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 Which one could be the good option to start with either air source heat pump or exhaust air heat pump to utilize waste heat from dryer exhaust?
Thank you!
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Prakash Adhikari an exhaust air heat pump (EAHP) is likely a better option to start with for utilizing waste heat from dryer exhaust, as:
- EAHPs are specifically designed to recover heat from exhaust air streams
- They can handle high-temperature exhaust air (up to 150°C) and humidity
- EAHPs typically have higher heat recovery efficiencies (up to 70%) compared to air source heat pumps (ASHPs)
- EAHPs can provide both heating and cooling, making them a versatile solution
ASHPs, on the other hand, are designed for outdoor air temperatures and may not be optimized for high-temperature exhaust air streams.
Starting with an EAHP can help you effectively utilize the waste heat from your dryer exhaust and achieve significant energy savings.
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I need to calculate the exit temperature of the heat source from the evaporator of a heat pump for a given situation. The heat source is a heat storage which provides source temperature of 40 °C. The flow and return temperature of the system is 70/50 °C, the heat demand is 100 kWh. The COP value of the heat pump is 3.0
The heat storage will be charged with the return (exit) flow from the evaporator. Thus, i need to know the temperature of it. What is the proper method to do this calculation ?
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How
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I would be grateful if someone could guide me how to get the input and output pressure in the compressor used in solar heat pumps? For example, in this article Annual comparative performance of direct expansion solar-assisted and
air-source heat pumps for residential water heating
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Otherwise check this publication below(not my own) . It will definitely assist.
Let me know
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unfortunately, i couldn't find any proper research papers about the influence of the flow-return temperature of the heating network (District heating) on the investment costs ( CAPEX ) of the heat generators such as CHP, Heat Pump and Biomass (Pellet,wood) boiler. I wanted to draw up a comparison between the heat generators in order to determine the most sensible variant for a given flow/return temperatures in terms of cost-effectiveness. I'm planning to establish a correlation between the temperatures and the capex.
I would really appreciate any help.
Best regards.
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To do this properly would require a lot of design and specification work followed by collating prices, so is barely feasible unless a case can be made that has not been done yet. The simple approach is to use the scaling rules for equipment e.g. the 0.6 power law. The cost of heat exchangers can be evaluated in tonnage or area terms: I would favour the latter. The area of the exchangers is given by A = Q/(U.LMTD) so scaling is fairly easy as U is set by flowrates mainly for a given design of heat exchanger. Thus, Area varies inversely with LMTD. The range of allowable flow-temperatures is quite small usually, the return value is controllable by the designer and more variable. Hope that this helps.
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Can the installation of heat pumps powered by renewable energy sources significantly reduce the scale of the increase in the cost of generating heat and power or completely solve the energy crisis that exists in countries with a predominantly coal-based energy industry and thereby increase the level of energy independence and security?
In 2022, the scale of sales of heat pumps in Poland increased by approximately 100 per cent compared to the previous year. This was due to the energy crisis generated by the slowing down of the development of renewable and emission-free energy sources by the PIS party currently in power over the past eight years and the promotion of energy development based mainly on burning combustible fuels, mainly coal and lignite. As a result, three quarters of Poland's electricity generation and even more of its heat generation is still based on burning coal. As a result, when the price of fossil fuels rose sharply between 2021 and 2022, the cost of living for many citizens increased by several tens of percent. The solution to the problem of rising heating and energy costs was to install heat pumps powered by electricity from photovoltaic panels installed on the roof or next to the house, or other renewable energy sources. However, these other alternative renewable and emission-free energy sources are few and far between due to energy policy. In order to increase the energy savings of their homes, many citizens would like to insulate their homes by renovating and adding insulation to the facades of their buildings. It is estimated that over 4 million residential homes in Poland lack thermal insulation. However, this is unfortunately not possible due to the overly limited financial programmes of non-refundable subsidies with which such investment projects could be financed. Many citizens, despite the fact that they would like, for example, to power heat pumps with electricity from a wind turbine, a windmill erected close to their home, have not had this opportunity because in 2016 the PIS government blocked the development of wind energy in Poland by passing the so-called 10h Law. Similarly, in April 2022, a change in the regulation of billing for photovoltaic panels installed on the roof or next to a residential house by citizens prosumers of their own electricity made these installations unprofitable and the number of new installations of this kind fell by three quarters. When the development of wind power in Poland was blocked in 2016, coal imports increased strongly. In addition, nuclear power and other fully renewable energy sources were not developed. The result is a low level of independence and energy security for the country. Besides, the result is one of the lowest air quality and high levels of smog in cities during the heating season in international rankings. Unfortunately, despite the existence of new renewable energy technologies whose application on a larger scale could solve the above problems, the scale of development of governmental and self-governmental programmes of financial subsidies and support from the European Union is still too small. And it is too small because Poland has not met the so-called milestones set by the European Commission and is the only country in the EU which has not received financial subsidies under the National Reconstruction Programme. One of these milestones is the issue of unblocking the onshore wind energy development previously blocked in 2016. Currently, i.e. in Q1. 2023, a law is being processed to unblock this issue. However, the still ruling PIS party, as part of its support for the development of coal-fired power generation and its support for government-controlled, monopolistically operating energy and fuel companies of the state treasury, included in the aforementioned law provisions that in practice limit the development of onshore wind energy (a minimum distance of 700 m between a windmill and the nearest buildings) so that only a few per cent of the country's area can be covered by these windmills. This means that a small proportion of willing citizens will benefit from this, and it will benefit mainly and also to a limited extent the government-controlled, monopolistically operating energy state companies. Thus the circle of this travesty of energy, climate and environmental pseudo-politics is closing. In view of the above, technological solutions that could solve the above problems are already available, but the national pseudo-politics of energy, climate and environment causes that the development of renewable and emission-free sources of energy, improvement of energy security, reduction of the scale of the energy crisis, improvement of air quality in cities is still being slowed down, the goals of sustainable development are being ignored by the PIS government, and the green transformation of the economy, achieving zero-emission of the economy, building a sustainable economy in accordance with counteracting the progressive process of global warming is progressing much slower than it could be.
In view of the above, I address the following question to the esteemed community of scientists and researchers:
Can the installation of heat pumps powered by renewable energy sources significantly reduce the scale of the increase in the cost of generating heat and energy or completely solve the energy crisis existing in countries where the energy industry is mainly based on coal and thus increase the level of independence and energy security?
What do you think about this topic?
What is your opinion on this subject?
Please respond,
Please answer with reasons,
I invite you all to discuss,
Thank you very much,
Best wishes,
Dariusz Prokopowicz
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Open Letter to Energy Involved Engineers and Researchers
There are proposals already known to build plants producing clean energy of refrigeration, heating or mechanical work by using the ambient temperature heat / sink source. The technology names generically “Mother and Father Hybrid Compression”, M&FHC. A recent author patent file applies in refrigeration and work yield, (Staicovici, 2023a). So far, power plants produce electrical work exclusively having the ambient temperature heat source as external sink and a higher temperature than sink as heat source. Such a plant was named (super-) ambient power plant or AP plant (Staicovici, 2023b), e.g. Rankine and Rankine-Gas Turbine plants. Unlike AP, M&FHC emphasizes a new concept of power plants capable to produce electrical work. These plants use the ambient temperature source as heat source and an artificially created source, of temperature below ambient temperature, as internal sink, named sub-ambient power plants, or SAP plants (Staicovici, 2023b). The AP plants produced until today most part of the planet electrical power. Except the hydro-power, wind-and wave-farms and possibly other few small clean power technologies, all the others power plants base on operation of (bottoming) steam Rankine cycle (SRC) or organic Rankine cycle (ORC), powered by fossil or non-pollutant fuels. Roughly, the SRC plants condensers evacuate to ambient sink a quantity of heat equal to 𝑞𝐶,𝑅𝑎𝑛𝑘=𝑞𝐺.𝑅𝑎𝑛𝑘(1−𝜂𝑤,𝑅𝑎𝑛𝑘) cycle anergy. In this equation, 𝑞𝐶,𝑅𝑎𝑛𝑘, 𝑞𝐺.𝑅𝑎𝑛𝑘 and 𝜂𝑤,𝑅𝑎𝑛𝑘 hold for the Rankine condensing and generator heats and power efficiency, respectively. If a mean 𝜂𝑤,𝑅𝑎𝑛𝑘≈0.5 Rankine efficiency is considered, it results the AP condensing processes reject to ambient a huge power worldwide, equal approximately to that produced. Most engineers and researchers involved in energy consider planet global warming is the result of 𝐶𝑂2 pollution caused by power technologies burning fossil fuels, characterized by limited availability. It is true, these technologies are the main cause for that, but this picture is not realistic to a good extent. Indeed, a large plants category do not burn hydrocarbon fuels and people consider them clean power plants. To this category, of “nonpolluting”, belong e.g. the actual Rankine plants powered by nuclear, biomass burning, or future fusion technology. However, they pollute the planet simply by rejecting in the atmosphere the condensing heat we mentioned earlier. The energy involved people attempt to solve the imminent catastrophic global warming by replacing 𝐶𝑂2 polluting plants with as much as more power plants belonging to the “nonpolluting” category, but this is far from being the solution. Indeed, first, because the hydrocarbon burning plants are most efficient and second, these plants are replaced by less efficient plants, which heat rejection of in the ambient could be even more pollutant. Here, we remember that a terrestrial object can be cooled through radiative heat exchange mainly in the “window” of the atmosphere, where this is essentially transparent in the wavelength region from 8 to 14 μm. The cooling is possible also outside the window where the atmosphere has radiating bands covering much of the infrared spectrum, but 𝐶𝑂2 is blocking in global warming all the Earth natural cooling channels. Because the global warming evolves rapidly and if not acting right, irreversibly, a realistic solution against chronometer is required. The solution could come from the introduction of the SAP technology. The author proposed lately a patent file, (Staicovici, 2023c), analyzing for the first time an AP & SAP energetic coupling. The AP can be either of “nonpolluting” or polluting type. The AP & SAP coupling applies until SAP will replace the AP in most possible applications. In the AP & SAP synergy, SAP is recovering as heat source the condensing heat rejected by AP to ambient sink, of 𝑇𝑀ℎ ambient temperature. In this thermal cascade, the energetic benefit is twofold, first, the polluting effect of the condensing heat rejected by AP vanishes and second, the power efficiency of AP coupled with SAP is significantly higher than that of the non-coupled AP. Finally, as a corollary, the global warming
Figure 1. 𝜂𝐴𝑃, 𝜂𝐴𝑃+𝑆𝐴𝑃 and 𝜂𝑊 AP&SAP synergy main functions vs. AP
Generator Temperature, 𝑇𝐺,𝐴𝑃,[℃].
decrease must be done using a technology that consumes the huge amount of heat accumulated in the atmosphere during industrial era and converts it in 100 % clean electrical power, and so far this technology is the SAP technology.
In Figure 1, 𝜂𝐴𝑃, 𝜂𝐴𝑃+𝑆𝐴𝑃 and 𝜂𝑊 functions involved in the AP&SAP synergy are plotted vs. AP generator temperature, 𝑇𝐺,𝐴𝑃,[℃]. These functions plot is for four steam Rankine plants powered by nuclear, biomass and fuel of hydrocarbon nature, or coming from the future fusion process. The steam Rankine plants are characterized by generator and steam superheating temperatures, 285℃, 330℃, 535℃ and 1300℃, respectively. The functions hold for work efficiency of AP, work efficiency of AP&SAP synergy, and ratio work yield of AP&SAP and AP. Further, 𝑇𝑀ℎ=36℃, 𝑇𝐷𝐼=−75℃, 𝜂𝑆𝐴𝑃=0.66 𝑘𝐽 𝑟𝑒𝑓𝑟𝑖𝑔𝑒𝑟𝑎𝑡𝑖𝑜𝑛𝑘𝐽 ℎ𝑒𝑎𝑡, 𝜂𝑒𝑥=0.7 and 𝐶𝑂𝑃𝑐,𝑆𝐴𝑃=6.6 𝑘𝐽 𝑟𝑒𝑓𝑟𝑖𝑔𝑒𝑟𝑎𝑡𝑖𝑜𝑛𝑘𝐽 𝑤𝑜𝑟𝑘 are SAP parameters holding true for external sink, desorber inlet temperature, work and exergy efficiencies and hybrid compression refrigeration efficiency, respectively. The 𝜂𝐴𝑃+𝑆𝐴𝑃 function shows work efficiency of AP&SAP synergy is approximately 1.5 - 2 two times higher as compared to 𝜂𝐴𝑃 function values. This result is a consequence of 𝜂𝑊 values, indicating that work produced by AP&SAP synergy is by approximately 1.5 - 2.3 times higher as compared to that produced by AP alone.
REFERENCES
Staicovici, M.-D., 2023a, Refrigeration and Work Mother and Father Hybrid Compression Procedure and Applying Plant, EP 23020142.8 / 17 March 2023.
2004006008001000120014002004006008001000120014000.00.51.01.52.02.50.00.51.01.52.02.5AP, W, AP+SAP, [-] AP Generator Temperature, TG,AP, [oC] AP W=WAP+SAP / WAP AP+SAP=W*APAP-SAP CouplingTMh=36oC; TDI=-75oCSAP=0.2513 ; ex=0.7 COPc,SAP=6.6
Staicovici, M.-D., 2023b, Mother and Father Hybrid Compression Plants For Refrigeration and Work Supplied by Ambient Heat Source. ICR 2023 proceedings, paper 0069, Commission E2, Paris.
Staicovici, M.-D., 2023c, Synergic Coupling Procedure and Applying Plant of Mother & Father Cycle and Plant for Refrigeration and Work, EP 23020391.1 / 21.08.2023.
Best regards,
Mihail-Dan Staicovici
Head Researcher First Rank,
Dr. Mechanical Engineer
Bucharest, Romania.
P.S. The author of this letter forwarded a flyer with the topic presented above to Dr. engineers Joselyn Bonjour and Gerald Cavalier during ICR 2023, August 21-26, 2023, Paris. Bearing in mind that France produces electrical power in proportion of more than 70 percent using nuclear power, the AP&SAP coupling technology may be a possible alternative towards a cleaner electrical power production in this country.
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I have modelled a heat pump and for a cooling capacity of 5 to 10kw, what would be the displacement volume, piston diameter and stroke length, number of cylinder in the compressor. I tried to research but I could not find, please do share
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Paride Gullo I am sorry I have a question here like the displacement volume usually come in cc ( cubic meter) here it showing 146 meter cube/ h , I don't understand what is it ?
Also the dia, it just this is diameter , diameter of what piston or vessel or anything else?
No info is showing for stroke length? Can you please guide me I will be thankful
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I am modeling a heat pump on the EES program and for the heat exchanger, I am using the NTU method to solve which requires iterations and I am unsure how to use it. If somebody explains it to me through an example then I will be thankful
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To design a thermoacoustic heat pump to lift a temperature of 50-60 degree Celsius. what are the design parameters for it and what is the cost of the heat pump.
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You can build the experimental setup under 5 to 7k. but it depends on the requirement. please share the requirements, I'll try to share the suitable compressor and equipment.
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What are the interesting topics in the field of air conditioning right now? or future of air conditioning?
Are we stuck with the conventional methods of air conditioning? a research lead that could save energy and efficiency in the field of air conditioning?
Looking keenly for my next mission, which is a PhD in the future of air conditioning, heat pumps, refrigerant cycle improvement, advance air cooler maybe, AHUs, duct sizing, air simulation, CFDs! Is their a way out to top what is currently available? a sustainable sufficient energy efficient method?
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A/C is a very "mature" field in that many smart people have been working on this problem for a very long time. All the "easy" things were done long ago. Most of the "very hard" things have also been done. You might want to reconsider your area of focus and select an emerging topic where new discoveries are more likely to be found. As Youssef suggests, new materials for heat exchangers, pumps, and refrigerants hold forth promise. Active thermal inertia devices that take advantage of diurnal variation is another topic that may be worth investigating.
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I need to know the entire design procedure of the heat pump. How the compressor is selected based on the refrigerant and temperature? How each and every component of a heat pump is designed and the theoretical calculations behind them.
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Remember that selecting the right compressor is just one aspect of designing an efficient heat pump system. The entire system, including components like the heat exchanger, air handler, and controls, must work together seamlessly to achieve optimal performance and energy efficiency. Therefore, it's essential to take a holistic approach to heat pump system design and consult with professionals when necessary.
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Which home heating systems based on green energy technologies should be developed in connection with the currently developing energy crisis and in the future also with the developing climate crisis?
If the currently developing energy crisis worsens significantly, how will you reduce your heating energy consumption and/or increase your household energy security in a situation where heating prices would increase by several tens of percent in the next heating season?
Nowadays, energy-saving solutions and systems are being developed due to rapidly rising fossil fuel prices. For example, solutions are being proposed for lowering the heating temperature in living spaces by a few percent when heating prices would still rise significantly. At present, many citizens are considering new investments in their household to increase energy security. Questions arise: maybe it is worthwhile in the near future, before the next heating season, to install new, renewable sources of heat and/or electricity at home, to insulate the house façade, etc.? Or are there already affordable new eco-innovations and green energy technologies that could be used now to increase energy savings? Besides, an energy crisis is currently developing and, in the long term, so will a climate crisis. When building a house now, it is important to take into account both the potential deepening of the energy crisis and the climate crisis in the future. In addition, the future correlation between the effects of both crises must be taken into account when planning heating systems and the electricity supply. Among the currently fast-growing green building heating technologies are the installation of heat pumps powered by electricity from photovoltaic panels installed on the roof of the house. In the future, the electricity supply for heat pumps may also come from domestic small-scale hydrogen power plants or nuclear fusion mini-reactors.
In view of the above, I address the following research question to the esteemed community of researchers and scientists:
Which home heating systems based on green energy technologies should be developed in view of the currently developing energy crisis and in the future also the developing climate crisis?
What is your opinion on this topic?
What is your opinion on this subject?
Please reply,
I invite you all to discuss,
Thank you very much,
Best regards,
Dariusz Prokopowicz
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How do local government units in your country inspire citizens to save electricity and/or heat, conserve water sparingly, segregate waste, and other pro-environmental daily practices and actions?
How do local government units, including municipalities, as part of their pro-environmental and pro-climate policies, inspire citizens to save electricity and/or heat, conserve water sparingly, segregate waste and other pro-environmental, everyday practices and actions?
There have been many different crises since the beginning of the 21st century, and there is little indication that this would change in the years to come. The dotcom crisis at the turn of the 20th/XXI century, the global financial crisis of 2007-2009, the global recession of the 2020 economy triggered by interventionist measures carried out during the 1st wave of the SARS-CoV-2 coronavirus (Covid-19) pandemic, the overly lenient monetary policy carried out during the pandemic, the strong rise in inflation and the risk of stagflation in 2020, the currently developing energy crisis, the currently developing food crisis in some poorer countries, the already ongoing climate crisis that will intensify in the coming decades. As the levels of various risks increase, the scales and frequency of various crises increase, more and more public institutions, government agencies, NGOs but also local government units are taking various anti-crisis measures. Currently, the currently developing crises in many countries are: the economic downturn caused by high inflation; the energy crisis caused by high fuel and energy prices and low levels of energy self-sufficiency and underdevelopment of renewable energy sources; the climate crisis (and in some countries also the food crisis), the consequences of which include severe heat and droughts causing a decline in the production of agricultural crops, increased energy consumption and other negative effects. The climate crisis is likely to develop for many more years. In some countries, due to the low level of energy self-sufficiency, the low level of development of renewable and carbon-free energy sources, the scale of the currently developing energy crisis is greater and in the future, the negative effects of the climate crisis may also be more severe for nature and humans. Accordingly, local government units are also inspiring citizens to use water sparingly, save energy, segregate waste and other pro-environmental daily practices and actions. However, there are big differences in this regard when comparing environmental and pro-environmental policies and realistically carried out pro-environmental activities and green projects by individual local government units.
In view of the above, I address the following research question to the esteemed community of researchers and scientists:
How do local government units, including municipalities, within the framework of their pro-environmental and pro-climate policies, inspire citizens to save electricity and/or heat, conserve water, segregate waste and other pro-environmental daily practices and actions?
Please answer,
I invite everyone to join the discussion,
Thank you very much,
Best regards,
Dariusz Prokopowicz
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The Clean Cities Campaign is a European partnership of civil society organisations that aims to encourage cities to move to zero emission transport by 2030. The campaign promotes green transport solutions for more liveable and sustainable cities. To achieve these goals, it is essential to phase out high emission vehicles from cities as soon as possible.
Imo, such campaigns are an important tool to reach the goal of your query, dear Dariusz Prokopowicz
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If the home is heated and supplied with electricity from various renewable, carbon-free and possibly also non-renewable energy sources, to what extent can energy consumption savings be generated through the use of computerised, integrated management systems for various heating, lighting, white goods, white goods, white goods, etc. smart home systems?
If the house is heated and supplied with electricity from various renewable, emission-free and possibly also non-renewable energy sources, when on the one hand the energy for heating water can be generated from the sun, heating the house can be generated through heat pumps powered by photovoltaic panels, possibly from geothermal sources, etc., the energy for heating the house can be generated from the sun, the energy for heating the house can be generated through heat pumps powered by photovoltaic panels, possibly from geothermal sources, etc., etc. Electricity can be generated from home solar and/or wind power and any shortfall can be made up from external energy suppliers. However, when there is too little sunshine and no wind, the shortfall in electricity must be made up from other energy sources to power the heat pumps that heat the house. However, when there is an energy crisis and high energy prices from external suppliers, powering the heat pumps can become highly expensive. In such a situation, a modern, low-emission wood-burning cooker or an eco-friendly fireplace fuelled by biofuels can be run as an emergency. As the weather aura changes and the price of electricity from external suppliers (energy companies supplying electricity and/or system heat) changes, this type of complex, multi-source heating and electricity supply system for the home needs to be managed continuously. It may then be useful to use computerised, integrated systems to manage the various heating, lighting, white goods, white goods, etc. smart home. Computerised, integrated systems for the management of various heating appliances, lighting, white goods, consumer electronics, etc. smart home can make use of a specific generation of artificial intelligence technology and other Industry 4.0 technologies. Through such solutions for the improvement of smart, computerised, integrated home energy risk management systems, savings can be generated in terms of thermal and electrical energy consumption.
In view of the above, I address the following question to the esteemed community of researchers and scientists:
In a situation where the home is heated and supplied with electricity from various renewable, carbon-free and possibly also non-renewable energy sources, what energy consumption savings can be generated through the use of computerised, integrated management systems for various heating, lighting, household appliances, white goods, consumer electronics, etc. smart home?
What do you think about this subject?
Please respond,
Please answer with reasons,
I invite you all to discuss,
Thank you very much,
Regards,
Dariusz Prokopowicz
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Dear Vjacheslav Fisenko,
The easiest does not always mean the best. Taking into account the issue of the pro-climatic transformation of the energy sector, a diesel generator powered by biofuel is a less emissive energy source compared to, for example, a coal stove. However, when completely emission-free energy sources based on home solar, wind and geothermal power plants are used, the air quality will be much better. The level of consumption in the heating season is lower and the level of the pro-climate transformation of the energy sector and the economy is higher. However, the problem is the issue of financing new pro-climate and pro-environmental investments, investments in the development of renewable and zero-emission energy sources, investments that are an important factor in the green transformation of the energy sector and sustainable development. It is necessary to increase the scale of financial subsidies under the governmental support programs for the pro-climate and pro-environmental transformation of the energy sector and to increase the scale of diversification, independence and security of the energy sector. Increasing the scale of diversification, independence and security of the energy sector through the development of renewable and emission-free energy sources is a particularly important issue not only in terms of reducing CO2 emissions into the atmosphere, counteracting the progressing global warming process, reducing the scale of the negative effects of the future climate disaster, but also due to the current energy crisis. Therefore, the current energy crisis and the prospective climate crisis increase the importance of the urgent and efficient implementation of the pro-environmental transformation of the energy sector.
Regards,
Dariusz Prokopowicz
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I am designing vertical geothermal heat exchangers, how can calculate the flow rate in u tubes per boreholes and also the total flow rate in the heat pump?
I used GHX tool (Excel) provided by Chaisson that use finite line source to calculate ground thermal resistance, did anyone have a description about the process of calculation ?
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I suspect you are asking the wrong question. You might ask, "Given such-and-such a system of this size and design, operating at these conditions (flow, temperature, etc.) what might one expect to see by way of heat transfer to or from the ground?" The information you have stated is incomplete and not nearly enough to evaluate the performance of such a system. You might begin with a tentative design based on one that has been successful in a similar setting and see how that reacts compared to the expectations you have, which have not been stated. You must have some expectations? watts? degrees? cost? life expectancy?
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Renewable Energy
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In principle, there is no objection, but it has to do with the available solar energy, other sources, and the application.
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I have the electricity consumption profile of a reversible heat pump covering 1 year. The heat pump datasheet contains the SEER and HSPF.
I also know the thermostat setpoint for the building as well as the ambient temperature for each day in the electricity consumption profile.
I will like to know how to obtain the thermal profile considering that COP changes with temperature ?
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Basically you should estimate the amount of heating demand/cooling demand as well as hourly heating/cooling profile of the buidling by the setpoint and ambient temperatures.
These give you the heat and cool supply of your heatpump and by using the electricty consumption of the heat pump you would be able to estimate the COP of the heatpump for heating or cooling mode.
there is a shortest way which is finding the corresponding COP from Charactersitic curve of the heatpump based on the supply and ambient temperatures of the set operation points.
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I would like to know what are the necessary steps required to perform a geothermal potential assessment for the installation of a Ground Source heat pump destined for heating and cooling buildings. It basically tells you whether a site is suitable for geothermal heating or not.
Thanks in advance.
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In both cases, I had the opportunity to open the papers mentioned in my reply.
Sorry,
Jorge
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Energy coupling technologies connect two or more types of energy systems (energy vectors) to each other.
For instance, heat pump, electric/gas boiler, CHP/CCHP, fuel cell, etc., are energy coupling technologies.
In this context, what other technologies do you know?
The following work may be useful in this regard:
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I appreciate you for your helpful answer in enumerating an energy-efficient and eco-friendly energy coupling technology that is beneficial in exploiting geothermal energy.
Best regards,
Omid
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For industrial applications in ground-coupled heat pumps, a vertical U-tube, horizontal (straight and Slinkies) pipes are used. In the ground condensers and evaporators, metal tubes such as Copper are utilized. Is it practical from the manufacturing and maintenance point of view to implement fins (internal or external) to the buried tubes?
Thanks
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Hi,
For ground source heat pumps (geothermal) I do not see the point of using copper pipes since heat transfer mechanism is penalized by the soil's poor conductivity. That's the reason why plastic pipes are used besides the fact that they do not corrode. At the end of the day, enhancing heat transfer coefficient of the tube (less thermal resistance) will definately not improve the heat pump performances.
Concerning added fins, theoratically increasing heat transfer surface of boreholes should enhance heat pump's performances. However, this should be done by adding other boreholes respecting distances between each of them to facilitate the ground regeneration. Adding fins definitely increases the heat transfer surface but does not allow to respect the necessary distance between the added surface and the initial surface (bare tube w/o fins) for regeneration purposes. At the bottom line, adding fins will not make a significant difference in my opinion.
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Is there any research prospect to improve the efficiency of heat pumps through the different coupling modes of solar energy and air source heat pumps?
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This is a good field of study. Know that many of the easy and obvious things have been tried but that doesn't mean that there aren't new and innovative approaches to be discovered. Don't let the current technology discourage you; rather, let it motivate you to press on for more. Master the scientific foundation and then build upon it!
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Solar heat pump is greatly affected by radiation intensity, resulting in unsustainable operation.
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The most effective but relatively expensive solution would be to integrate thermal storage, so that you will have a constant heat source. In addition, I suggest this one might be helpful for you as well https://mdpi-res.com/d_attachment/energies/energies-14-03534/article_deploy/energies-14-03534-v2.pdf
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Dear All,
I am looking for international standard(s) to evaluate the rated capacity of thermal driven cyclic heat pump such as adsorption cycle for cooling or heating purposes. Do you have suggestions? Thanks!
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Hi,
As far as I know, there is no specific standard for adsorption chiller.
Heat-driven chillers are tested in accordance with AHRI 551/591 (SI) 2020 including addendum 1 or with on of the following compatible standards AHRI 560-2021 (completed but not yet published), ANSI/ASHRAE standard 30-2019, ASHRAE 182-2020 and ANSI/ASHRAE/IESNA 90.1-2019 with addendum X and Y.
Hope this hepls.
Regards
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Hi everyone. Does anyone know how to model an air to water reversible heat pump to feed the heated and cooled floor (radiant surface) in Designbuilder detailed HVAC? I can find air to water heat pump only for heating and it is not possible to make it reversible.
Thank you in advance.
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Prince .. Thank you very much for the document!
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I want to simulate the heat pump (air source) with unite storage thermal Tank but I get the following msg:
''350 : Unable to open the file associated with an
ASSIGNED logical unit number.
Please check the ASSIGN statement and make sure
that the file exists at the specified location''
and I want to,know also how can I creat a file
external if necessary
thank you
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Dear Munsannif
For the problem of the external file, I have a problem in the data file because the component I have is empty, so I created my own data file based on the documentation available in the installation file TRNSYS. After that, I verified the right data from an X manufactring for my sizing calculation.
After, I have import the new data file into Heat pump component.
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In my project, I am designing a heat pump system to replace the current one.
I have done some calculations and I have the refrigerant flow rate required for the cooling load to be achieved.
How do I calculate how much refrigerant (Kg) goes into the circuit?
I have the loop length of the circuit and the diameter of the tubing.
Any help and literature recommendations are appreciated.
Thank You
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It is important to start with modeling and simulation of the whole heat pump circuit to get the optimum conditions. In the modeling process, you will get the amount of refrigerant at high COP. I wish the following paper link is helpful for you:
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I was wondering if you could help me with a simulation as I am new to the programme, I am new to Abaqus and any help would be appreciated. I need to model heat transfer between the soil of temperature approximately 12 degrees and a concrete pile foundation with a pipe carrying water flowing through it of temperature of approximately 5 degrees. What's the best way to do this?
It is essentially the modelling of a geothermal heat pump but would like the readings of the drop in temperature in the soil.
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The book by Carslaw and Jaeger, [1], gives some examples of problems concerned with heat conduction in soil, and discusses where to find information for the thermal properties of soil. The book by Incropera and DeWitt, [2], has some thermal properties of soils and concrete listed in its Appendix A.
[1] H. S. Carslaw, J. C. Jaeger; Conduction of Heat in Solids, 2nd Ed.; Oxford University Press; 1959; pp. 81-85, see the footnotes on p. 82.
[2] Frank P. Incropera, David P. DeWitt; Fundamentals of Heat and Mass Transfer, Second Edition; John Wiley & Sons; 1985; pp. 755-784.
Regards,
Tom Cuff
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Power-to-heat (P2H) shows how we can use renewables for heating. Power-to-heat technologies have been on the market for quite some time now, with heat pumps being the most important. However, they are only efficient at lower temperatures. Whenever very high temperatures are needed – for example, in the industry – electrode boilers are used.
So what do you think? Which technologies do you think will substitute the current fossil-fuel-based heaters in the future European energy system?
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I think the major source will be direct solar heaters. Especially in the European countries in the south and east of Europe where they are rich with solar radiation.
For very controlled heating for industry one has to use the photovoltaic generators.
Best wishes
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My model is a rectangular multi layered structure under which refrigerant flows through cylindrical pipes. A heat flux of 600W/m2 applied on panel and internal forced convection is used for refrigerant flow. Trying the phase change option from heat transfer in solids and fluids node but I am not getting any sollution.
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Dear Sir/ Madam,
I need a manufacturer data of high temperature (70-80 Celcius) heat pump system for district heating network. I need a heat capacity table of an industrial heat pump to create quadratic equation of COP characterization.
Where can I find such heat capacity table/data for industrial heat pumps?
Kind regards
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I recommend this paper for the regression model of water/air heat :
A. Khouya, Performance assessment of a heat pump and a concentrated photovoltaic thermal system during the wood drying proces, August 2020, Applied Thermal Engineering 180:115923. DOI: 10.1016/j.applthermaleng.2020.115923
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I am developing a regression model to predict the mass flow rate of a Direct Expansion Solar Assited CO2 heat pump (for a needle valve expansion device). The mass flow is based on the following equation:
m = Cd * A * [2 * rho * (Pi-Po)] ^ 0.5
For tests done in the sun, we have found a cd greater than 1. I expected this correction factor to be less than 1. But my experimental data, apparently show the opposite.
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I think,there are mistak with uint of this equation.please check the units for all parameters within this equation.
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Good morning,
I am a student of the Mechanical Engineering Course of Udine University. Since I am at the last year of the course (fifth year), I am moving in order to collect information about the thesis. The theme I would like to deal with is the thermal management of the cabin and of the battery pack of an electric vehicle; my aim is to build a thermal model so as to be able to study the needs of cooling and heating of the vehicle and make considerations about possible ways of reducing energy consumptions of AC systems.
More specifically, in order to build an initial simple model of the heat pump system of the electric car, I should know the condensation temperature (or pressure) and the evaporation temperature (or pressure), in both cooling and heating mode, of the refrigerant used. I have made some research, and I have found the article "Performance evaluation of an integrated automotive air conditioning and heat pump system", that's why I am writing here. I have also found some other tables (here attached) which report reference numerical values.
Therefore, I have concluded that, in the cooling mode, the evaporation temperature of the refrigerant ranges from -2,5°C to 12,5°C and the condensation temperature of the refrigerant ranges from 50°C to 60°C. In the heating mode, instead, the evaporation temperature ranges from -4°C to 8°C, while the condensation temperature ranges from 45°C to 55°C. Do you think I can take these values as reference for my thesis, or could you gently provide me more precise numerical values? Thank you.
Best regards
Alessandro Fabiani
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Ok, thank you for the indication.
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Since the instantaneous values of the compressor power requirement, pressure and temperature values at various locations of the circuit, and mass flow rate are highly fluctuating during the operation of VFD compressor-based heat pump system, what may be the better method to perform the energy and exergy analysis. Analysis based on the average values is giving some unbecoming results.
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A study on a laboratory model or theoretical pedal can be carried out, then the effect of compressor speed (i.e. refrigerant mass flow rate and the refrigerant pressure ratio) on the exergy efficiency can be investigated.
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It is well known the impossibility of building a Perpetual Motion machine of any kind, but I want to talk about the following issue ...
the idea of building a perpetual motion machine using the Thermoelectric Effect (be the Thomson Effect, the Seebeck Effect or the Peltier Effect) is very tempting , since ideally the Thomson Effect and the combination of the Seebeck and Peltier Effect can be thought as a ideal reversible thermodynamic cycles ...
So I'v been thinking for a time now. How can we explain the impossibilities of building such perpetual motion devices; such a free energy running Thermoelectric Generator, a Heat Pump or Refrigerator.
I have been thinking such the irreversibilities should be in the electron/holes transport, as well as Phonon transport, sure these particles should create new amount of Entropy
Can anyone explain this in a coneptual and descriptive way , at a fundamental level (i.e.
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Dear Rüdiger Mitdank:
I understand, there is an internal driving force (not just a Temperature Gradient, but also an Electric Potential Gradient), and I understand; since heat and charge transport have a statistical origin/or behaviour , just a window of this function can be used by the transport phenomena.
I understand as well that the Carnot Efficiency will be higher than the maximum efficiency of a device of this kind,
But what I want to understand is; What is the reason, at the physical microscopic level. In otrher words: Where we can find those irreversibilities which make the device cannot continue running perpetually (in the case of a TE device , to continue generating a current and and generating a Temperature difference, and so on ...
I know, macroscopically we can advocate to the "efficiency less than the Carnot Efficiency" argument and this could be sufficient by practical terms.
But I want to go deeper. ¿What does cause this efficiency to be less than one?
If you think on a simple TE material (no contacts, no module, no p-n pair).
If dS/dT is different than zero, then we can observe a Thomson Effect in our material.
Now, lets imagine we can isolate this block of material, and place it into a closed circuit... made with a superconducting wire (rho=0) and isolate the wire as well (thermically and electrically), so the losses through the ambient nearly approach to zero.
Then, ideally, this material will generate its own Heat Flux (due to combination of the Ohm's Law and the TE Effect, and the Fourier's Heat Flux Law), and this Heat Flux will generate a Current .. and go on, continuously, ideally with no losses (when imagining the ideal case of idual insulation).
But we know this is impossible, because the First and/or Second Law of get on our way. And ultimatelly, if we can defeat the 1st. and 2nd. Laws of Thermodinamics using the most futuristic and advance combined isolation-vacumm-cryogenics-superconducting technology... Well, at the microscopic level, there will always be irreversibilities (friction, energy losses, etc.) and ultimatelly Quantum Mechanics won't allow us to build this perpetual motion device that runs forever, it is impossible to build a perpetual motion machine of any kind, and one using the Thomson Effect (or TE Effect) is no exception.
But what I'm saying is that the TE Effect (Seebeck and Peltier Effects combined) and the Thomson Effect, are two visions than particularly easily can lead to thoughs about a perpetual motion device, because the way I described these Effects above.
I was thinking to an answer to my question, but I have it far from clear, What I started to devise is the following:
Maybe the explanation is somehow in the Entropy generated by the carriers (holes and electrons) they transport in the crystal ... I have seen some approaches where an finite amount of Entropy can be assigned to the transport of a Particle , like and Electron or other fundamental particle. so It could be that at the microscopic level the transport of these charge carriers generates Entropy, which then this Entropy transforms into irreversibilities of the system at the nanoscale level.
But... I don't know if we can come up with a formal definition of Entropy for a particle at this level .. or a mathematical expression,
Besides, the other issue is... What is up with the Phonons? It could happen the same logic could be applied to them?... If so, What about the Entropy production of each Phonon? since Phonons make up a condensate of Phonons... So? then, the case for Phonons seems to be a little different.
I will stop here I hope we can summarize our disscurion, hope someone else provide more ideas to it .
Kind Regards Rüdiger Mitdank !
Franklin !
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Hi,
I'm modeling a heat pump using ammonia as the primary refrigerant and I'm evaluating the UA values of of the evaporator and condenser. I'm trying to find a reliable source of UA values for them, preferably a range looking at different type of HX (flooded, plate etc.) to use as a comparison.
Thanks in advance,
Matt James
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Dear researchers,
Have a nice weekend with your family....
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I am working on heat pump assisted reactive distillation column. Trying to develop aspen plus model of vapor re-compression in reactive distillation column. the process includes three recycle streams ( one from separation column, one reflux stream and one reboil stream). I have used direct substitution method to converge the flowsheet. All blocks converge to desired results. But simulation ends with the error "solver block didn't converge in 100 iterations" and " solver block didn't converge normally in the final pass." increasing the no of iterations have no effect as depicted in convergence history chart. chart becomes linear. Not able to solve this error despite trying number of options. If anyone can help with this, it would be a great favor.
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You probably need to look closely to see if it really is converged or if it is very close to being converged. Can you print out the iteration history to see if it is oscillating between 2 or more solutions If it is a smaller step size or a change of convergence methods might help.
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There are are a large number of emerging areas for uses of copper.These include e- vehicles,renewable energy sector,in starter and rotors of giant turbines ,high-efficiency thermal heat pumps,solar panels,hospitals,aquaculture etc.Copper demand growth opportunities are high
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Though the utilities mentioned are high, but there are a few points to be looked into. For e.g.India imports major requirements of Copper as its natural resources are highly inadequate to meet its demands. Most of the imports are from African countries & its entry point in India is through JNPT & the Logistics corridor development is still in its infancy in India. Being imported in Trapezoid bars form, turning it into various end products involves high use of energy & except a very few states, most of them are deficient in this sector.
Atmospheric carbon dioxide has affinity towards Copper, giving it a green covering of Copper carbonate on its storing. Hence the turn over of finished goods has got to be substantial, unless protective covering is given.
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Hi all
I have data (e.g. T(out), operating hours and output power of the compressor, length of borehole) from a lot of Ground Source Heat Pumps. Can they be used to calculate subsurface temperatures? If yes, how? And do you have any idea how accurate these calculations are? Are we talking about errors in the range of < 1 °C or several degrees?
Thank you very much for your help!
Daniela
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I think you could try to perform an energy balance on the boreholes, but you need to have a precise knowledge both on the operational parameters (temperatures and mass flows) and on the design parameters (materials, conductivity, etc.). In theory you could obtain precise results, but of course it is strictly related to the quality of the input data you have.
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In order to integrate the geothermal as the primary source into the DH system, is it possible to only use heat exchanger to exchange the heat geothermal fluid in the separated loop or heat pump is the only option for this purpose?
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Needed in the determination of the COP of the heat pump unit base on the ratio of useful thermal output and the electrical input
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Dear Loh
The Ultrasonic flow meters is used to measure the volume flow rate of the refrigerant. Or you can use the float flow meter, electromagnetic flow meter and turbine flow meter.
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exergy efficiency comparison
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Condenser is a party of heat pump. I'm the condenser the useful energy is its suplied heat, where it's the same of the heat pump. However heat pump request other work for its functioning ... for that the exergitic efficiency of the condenser is more than heat pump.
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Hi
How can I calculate run fraction (Fc) based on bin method in ground source heat pump?
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Generally, run fraction calculated by degree days method. The following may be help you.
Shen, B., Baxter, V., Abdelaziz, O. and Rice. K. (2017). CCHP –Finalize field testing of cold climate heat pump (CCHP) based on tandem vapor injection compressors (Regular)– FY17 2nd Quarter Milestone Report. OAK Ridge National Laboratory. Page 5.
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My question is about the simulation of an internally heat integrated distillation column (HIDiC) by using as software ASPEN PLUS. My main question is related how to calculate the exact amount of heat that can be exchanged in each stage between the rectifier and the stripper?
Thank you in advance!
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Hello! Thanks for both answers! Washim I want to ask you if you have worked with HIDiC, because I wanna ask some more specific questions?
Im looking forward for your answer!
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If a bivalent heat pump unit serving a water-based circuit (that heats and cools an office) is working between evaporating at 5°C and condensing at 45°C, from a refrigerant condition point of view, how quickly can this unit be turned off?
The reason behind the question is building-grid interoperability when at times of grid congestion heat pumps can be turned off. I am wondering if the refrigerant operates between the temperature points outlined above, it might be necessary to run the heat pump for few seconds to allow the refrigerant to settle or move back from a super critical state (?) where otherwise and with a sudden shut-down the heat pump might be damaged.
Any advice or source of info would be great.
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Hi Mohammad,
In this case, it is better to adjust the control valve which is installed according to the expanded valve. Try to balance the system pressure.
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With solar heating systems characterised by their relative low flow and high head, I was wondering what the state of the art is with regard to solar application specific circulation pumps? It seems that many systems employ circulation pumps that run at extremely low inefficiencies.
As my experience with circulation pumps is limited, I would greatly appreciate any comments related to this query. 
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Do you really mean "... that run at extremely low inefficiencies." ?
If you meant "at low efficiencies": this is true for some older installation. Current installations should include variable speed, electronically controlled pumps (as Valeria Palomba stated), delivering reasonable efficiencies.
The main reason for this are the costs for electricity per kWh. Thus, in countries with low electricity costs low efficiency pumps may still dominate due to lower initial invest. But it is reasonable to go for high efficiency pumps: not only to lower energy consumption (which may or may not pay off), but also to increase pump lifetime (lower power, (eventually) lower average rpms -> lower operating temperatures -> longer life).
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I am eager to know if it is logical enough from the Heat Pump point of view to switch it e.g. 80-100 times a day? How does it affect the life-cycle of the Heat-Pump? it would be really helpful if someone can share their practical feasibility insights on this. I am an electrical engineer and I have no expertise on the Heat-Pump operation. Literature suggests this control of switching, but I want to know whether it is really practical to do so.
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Short-cycling a heat pump wastes energy rapidly. The "ancillary services" you provide by cycling the unit would be swamped by the increased energy used as the unit fights to restore the desired temperature. Ideally, you would have a variable speed heat pump that runs continuously at low speed. Short-cycling heat pumps are typically the result of bad design.
Heat pumps are low temperature devices, unlike fossil fuel systems whose output temperature is high. With a fossil fuel furnace, you can blast hot air to overheat the living space quickly and then wait for indoor temperature to drop before blasting hot air again. With a heat pump, you want to be constantly balancing thermal output of the heat pump against the thermal loss of the structure. The goal should be to keep the indoor temperature constant, not varying around an average temperature as you might with a fossil fuel furnace. (This is one reason why heat pumps increase "comfort" over a fossil fuel system.)
In addition to wasting energy, short cycling will also reduce compressor, fan and pump life since short cycling forces the equipment into high speed modes.
If you want to increase heat pump efficiency, consider using a thermal battery. For instance, at night during the cooling season, use the heat pump to cool water in a thermal battery or produce ice. You would then use the thermal battery as a thermal sink during the day. To support heating, you would heat water or melt ice during warm parts of the day and then use the thermal battery as a thermal source during the colder periods. In all of this, the goal is to keep the heat pump running at a constant slow speed. You use the thermal battery to smooth the demand over the day.
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What type of heat pump is the best choice to recover thermal energy from a small sewage water treatment unit?
“best" means compact with minimum power requirement.
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Any suggested literature for thermo-economic analysis of heat pumps, particularly for low temp (sub-zero) applications.
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I can suggest the following papers:
Esen H, Inalli M, Esen M. Technoeconomic appraisal of a ground source heat pump system for a heating season in eastern Turkey. Energy Convers Manage 2006;47(9–10):1281–97.
Esen H, Inalli M, Esen M. A techno-economic comparison of ground-coupled and air-coupled heat pump system for space cooling. Build Environ 2007;42(5):1955–65.
Hepbasli A, Akdemir O. Energy and exergy analysis of a ground source (geothermal) heat pump system. Energy Convers Manage 2004;45:737–
Esen H, Inalli M, Esen M, Pihtili K. Energy and exergy analysis of a groundcoupled heat pump system with two horizontal ground heat exchangers. Build Environ 2007;42(10):3606–15.
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Hi
I need Equations for Compute the geothermal system components?
Heat pump
heat exchanger
Borehole length
Design flow rate
Thanks
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Please see attached file
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 In performing  transient simulations with ansys fluent (Workbench),The ansys file that is
created is huge (148 GB),and I have 27 case to simulate.
                                                                                                                                                                         I am looking for any way to reduce the size of the results file.
Observations:
- In all cases ,I am interesting just for the inlet and outlet of fluid temperature and it's velocity.
- In all cases I have to simulate 93 days ,and all days contain the first 11 hours (I want to record it results ) and the last 13 hours(I am not interesting to record it).
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You can use the command:
OUTRES, Item, Freq, Cname
the following link explains to you how you can use it......Best wishes.
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I simulated ground coupled to heat exchanger with Ansys fluent and I want to calculate the mean thermal energy (KWh) transferred to the heat exchanger from the soil.
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But do you see an increase in temperature in the heat exchanger? If so, I guess you're integrating over  "both sides" of the interface, so that the ingoing and the outgoing heat flux add up to zero.
If you have a water or gas flow through the heat exchanger, you could also simply calculate the energy input into the fluid via Q=massflow*Cp*deltaT.
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We are talking about dumping heat from 4 peltier element combined connected parallel to a 12V supply having ratting of 100 watt approx each.
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You could try using a computer processor water cooling system coupling it through a thin layer of conductive paste. Considering the power you reported (100 W), the size of such device should be perfect.
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I am trying to simulate a specific type of an Absorption machine under Trnsys, the machine is a Yazaki 17.6 kWcool.
My question is how can I create a parametric file of the Type 107 to meet the performance of my AB machine ?
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I'm having the same problem, the external performance data for modeling the absorption chiller using Type 107 requires:
- Part load fraction to chiller
- inlet hot water temperature
- Inlet water temperature to the evaporator 
- Inlet cooling water temperature 
I think the absorption chiller you mentioned above is the Yazaki WFC SC5, for this and other size, the manufacturer defines the performance of the chiller using the last three parameters, nothing about the part load fraction chiller.
To be more specific in the manufacturer datasheet is shown the effect of water inlet temperature and hot water generator inler temperature on the design heat input and chilling power factor, giving the fraction of design heat input and the values of fraction of related chilling capacity.
What I'm trying to create is a simple model that allows to predict Yazaki's performance using the equations for the absorption chiller heat balance.
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I plan to start working on paper for Geothermics journal very soon where I will present more precise method of determining thermal conductivity by analyzing fall-off period after "classical" TRT time of min 48-72hr or longer. I have own sets of data which I measured on inclined coaxial heat exchanger (2*50m breholes drilled at 65° angle and equiped with coaxial probes 63/32 connected in series to achieve 100m in length). Data is 72hr TRT time and then equalt time recording fall off period with 3 different power supply. Since there is always power deviation during TRT (commonly due to day/night voltage fluctuations using public electricity grid) results of thermal conductivity always carry certain error in analysis. By analyzing fall-off period where there is stable decline in temperature could lead to overall more precise result in thermal conductivity, as prime factor in determining borehole grid size.
So, if anyone has some own TRT data gathered on BHE (preferably on 100m depth but not limited to) would be good to connect as possible co-authors and present measurements from different locations and geological setting.
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Wonjun, thank you very much for reply. Indeed, Horner analysis is the idea. Since I am petroleum engineer originally I have done a lot of well testing on oil wells (mainly pressure buildup tests). Since line source is also applicable and frequently used in petroleum engineering, Horner method and derivative curves could give more precise results in thermal conductivity determination. It is quite the same procedure to get permeability of reservoir.
Since I am focused on geothermal applications for awhile now, I would like to connect TRT and well testing from petroleum research in a science paper. Also to introduce skin factor in thermogeology terms, as skin is degree of formation damage around the wellbore (lower permeability) due to mud infiltration in pores. In thermogeology, as you know it is the same thing with thermal resistance, if grout is lower conductivity than the ground (plus thermal resistance from pipes etc.).
I have done in Croatia more than 20 TRT's on different geologic environment for commercial projects (1U, 2U and coaxial) but in practice is very hard to fully test recovery time due to timeframe of the project.
Therefore, we have drilled borehole at University, 2*50m of inclined boreholes (110mm) and installed coaxial heat exchangers 63/32. Heat exchangers are connected in series to get 100m in length. TRT was carried out  at the borehole proximity as much as possible with complete insulation (to avoid thermal disturbance) and with 4 different heat steps. The general idea is since TRT most often use electricity from construction site there is power fluctuations during day/night, to analyze recovery period as a more precise method. I have made all the calculations and results are very interesting.
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Hi.
I want to know how air temperature can effect on air source heat pump operation ?
How we can illustrate it on heat pump T_S diagram?
Thank you so much.
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In simpler terms: As the outside air temperature increases or decreases relative to the desired inside temperature, the efficiency of air source heat pumps will decrease. Air source heat pump efficiency will be lowest when the outside temperature is either very high or very low, relative to the indoor temperature. This is important when considering the impact of air coupled cooling or heating on electric demand. Typically, these devices will produce the largest energy demand at times when electricity demand is already peaking. In fact, it is air-source heat pumps and air-conditioners that are a primary cause of energy peak demand during hot periods.
The efficiency of geothermal or water source heat pumps is much less impacted by the outside air temperature since such systems are not coupled to the outside air but rather to the ground or water which will typically have a temperature much closer to the desired indoor temperature. 
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what is the design pressures for condenser and evaporater in heat pump for a home?
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You can use ASHRE standard to find out the design pressures and temperatures for R 134a.
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I would like to know your practical experience about Open Loop GWHP (Ground Water Heat Pump) in confined aquifer. In my case I have 1 extraction well and 1 reinjection well. The problem is the rapid worsening of absorbability of reinjection well (from 15 l/sec to 3 l/sec in 12 months).
Thank you
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Hi Roberto,
It sounds like you're having an injectivity problem. What are the chemical, physical conditions of your system? Poor injectivity in such wells can be caused by various precipitation/scaling reactions, for example due to mixing of different water chemistries, or a large difference between extraction and injection temperature. If you're injecting into a different aquifer than where you are extracting from this could also be a cause.
Curious to hear more about your system. Feel free to send me a message.
Best regards,
Niels
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The PCM whose latent heat of fusion is more and must have high cyclicity.
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I would suggest 1-decanol; having the fusion enthalpy of approx. 37.7 kJ/mol (*) at the (normal) fusion temperature of approx. 6.6 ºC.  
(*) J.A. Dean (Ed.), "Lange's Handbook of Chemistry", 15th ed., 1999, McGraw-Hill, p. 6.58.
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Just a range of usual values will do.
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Dear Kae Luen Toh
Greetings,
Please find the attached file very related for your topic,
Best Regards
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Hello Friends,
My pump flow capacity is 50 LPH and head requirement is 3.5 m.my pressure range is between 5 mm of hg to 70 mm of hg.My solution density is about 1600-1800 kg/m3.I have tried diaphragm pump,submersible pump ,magnetic rotor pump but all these pump didnt work properly.Is there  any pump available in market that is suitable to my requirement?
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Dear friend,
Centrifugal pump suitable for all application, try to chose the best.
regards  
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The Laval Nozzle has been designed for given inlet and outlet pressure, so the throat is after certain convergent portions. Let's say however that the pressure inlet is changed from the design pressure, what will be it's effect on nozzle's performance? Will the flow adjust itself and get the lowest diameter at throat or will it mess up due to Mach no lower than 1 at the divergent portion inlet? Would the divergent portion act as a diffuser?
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In application of an ejector, increasing pressure of the motive medium may bring the shocks which are in the mixing chamber back to the nozzle exit and fail the ejector.
On the other hand, it changes forms of shocks in a way that velocity in the center line of the diffuser becomes sub-sonic early and this leads to a decrease in ejector performance.
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I am using the commercial library TIL to construct a Heat Pump cycle in DYMOLA. When integrating the components to form a closed cycle it fails to start (fails to reduce the DAE index). However when testing the components separately shows no such error. Can anyone help me to know the probable reason for such an error and suggest any method to overcome it.
Thanks in advance :)   
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Dear Aryan,
what is a bit unconventional with the TIL is the concept of pressure state calculation. As far as I know there only two position where the dynamic pressure is calculated (in your model the der(i) blocks, one for high and low pressure, respectively). All other pressures are depending statically on these high and low pressure states. I would expect that if you had no pressure loss at one of the heat exchangers between the pressure state points then this would result in a DAE index problem. Which components are affected by the DAE index problem?
Concerning mass energy storage: In principle the heat exchangers' balance equation will feature energy and mass storage (i.e. dynamic enrgy and mass balance are supported). What they probably not provide is a mean to outbalance larger density variation due to load changes. When the evaporator load is increased the mass in the evaporator will fall and this mass is stored usually in some storage device like a feedwater tank (large stationary applications) or a condenser hotwell (smaller, mobile applications). If you donot have this components or something similar providing this functionality then your system simulation will be a) difficult to initialize (aside from your DAE index problems) and b) difficult to control. In this sense the simulation is comparable to the real world! So you might want to check the library for some kind of separator model or two-zonal model
Hope this helps.
Friedrich
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The problem is to match the pinch point conditions at the absorber and the desorber of the LiBr-water absorption chiller, and also to evaluate the needed/evaluated concentrations of the LiBr in the LiBr-water solution.
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Hello Tauseef,
Use pressure-temperature-concentration diagram and enthalpy-temperature-concentration diagram for LiBr-water solution in addition to energy balance and mass balance equations.You will eventually get the required concentration in the absorber and desorber.
If you have more doubts then please let me know,
Good luck!. 
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It should be a heat pump model to heat air to about 65 degrees and the evaporator side may be used as an air dehumidifier. I need the correlations for different components of a basic HP so that I can convert it into Modelica code.
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Dear Aryan, when I had to model the HP I used:
1. Polynominal values for compressor (usually compressor manufacturer can give them).
2. Moving boundary model for heat exchanger.
3. Empirical correlation for capillary tube.
Overall the model was able to predict the capacity and the COP within 5% with respect to experimental data.
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I want to calculate the experimental uncertainty for a geothermal heat pump as the reviewer suggestion of my paper?
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See the book Experimental methods for engineers by J.P.Holman.  There are books by other authors also.  
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Does anybody know how to configure Type 917 for a single zone building? I've been trying the example in the TRNSYS 17, however, I still couldn't tweak the performance of the Type 917 AWHP? Does anyone have experience using it?
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The following literature may be useful for your research work
This paper presents a TRNSYS simulation case study on the integration of a heat pump into a hot water and cold water storage systems for the purpose of providing heating and cooling to a residential home or office building in a tropical climate. The motivation is to utilize waste heat rejected by the heat pump.The heat pump is integrated with two water storage tanks. One is the cold water tank where heat is extracted by the heat pump and the other is the hot water which stores the heat rejected by the heat pump. The cold water tank provides cooling water for air
conditioning to the building. The hot water tank is used for daily usage like bathing and washing. The sizing of the two storage tanks and the balancing of the heat transfer
between the two tanks are important design factors to maintain suitable temperatures in the storage tanks. Thepaper discusses the performance of the integrated system
under different operational modes and the effects of eachstorage tank size on the performance.
Ref:A TRNSYS Simulation Case Study on Utilization of Heat Pump For both
Heating and Cooling
S.M. Al-Zahrani; F.L. Tan; F.H. Choo
Energy Science and Technology
Vol. 3, No. 2, 2012, pp. 84-92
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I am working on ASPEN simulation for an OSN membrane which requires pressure to be set at 30bars but my exit stream from the pump is giving a very high temperature at the same pressure and low discharge flow rate
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As suggested by Luo, you may try to cool and condense the stream before pumping, so the temperature of liquid streams practically have no rise.
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The sun is delivering a large amount of heat.
Buildings with large windows are able to collect this. Normally architects avoid overheating of building rooms by the sun. Otherwise there is the chance to use this heat and cool the rooms by air/water heat pumps. The stored heat can be used for warm water supply or to heat the rooms at the evening/night when outside temperatures go down.
For calculating the heat amount of the sun I need information about the volume of the sun input in dependence of the windows areas / building construction / region / seasons /....
Can anybody help?
With best regards
Michael
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Dear all;
these are good and almost complete data on the the question topic. In addition, the following missing books seems to cover precisely the use of solar panels on buildings. Regards
Building Science: Concepts and Application By Jens Pohl; 2011, (280 Pages); ISBN: 0470655739
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The notion of cascading for heat pump systems have been well developed to address efficiency drop in cold climates. Do you think it (cascading) also would help to enhance COP of system even for not critical working conditions?
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please, can you precise your question
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ASHP Systems
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Thank you very much indeed Andrea for your useful paper that you have sent to me, yet am still looking for ASHP more than GSHP thank again Andrea.
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I have read many articles about this topic. I wanted to hear some expert opinion about it. In my case. I'm interested in the flows of matter and energy coming in and out from the pump to the two different environments, and are not interested in the various internal losses and destruction of exergy.
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I always go through each component of the system one by one, you have inlets and outlets, then you apply your equations. Actually in HP you are dealing with less parameters compare to let say power plant.
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There are good methods for modeling of water to water, Water to Air and Air to Air Heat pump, like parameter estimation and equation fit, but I couldn't find any method for modeling this Air To Water Heat Pump.
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thanks Fred for your good attached file.