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Thermal Analysis of a House Made of Composite Wall Comprising of Solar PV Panel and Epoxy/Al Polymer located in Gulmarg
Abstract
Thermal analysis of a house situated in Gulmarg made of composite walls comprising a solar photovoltaic (PV) panel and an epoxy/Al polymer has been performed analytically for a day. The PV panels absorb solar radiation; a part of it is used to produce electricity and the rest is converted to heat, which increases the temperature of the panel. The polymer sheet attached to the panel absorbs heat from the panel and conducts it to the room inside. The east, west and south walls contribute to heat transfer from the outside to the inside of the room. The northern wall is cool compared to other walls and contributes significantly to heat losses. Room temperature was found to increase uniformly and attain 26.4°C by 5 pm, thereby reducing the requirement for room heating during the daytime. It can be concluded that the composite wall is able to heat the room and can produce electricity during the daytime to meet energy demand.
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This work reports the development of a methodology for the measurement of thermal conductivity of thermosetting polymers during their cure. The study addresses the reliability and robustness of the method through FEA modeling and testing using a noncuring material with known thermal conductivity. The thermal conductivity and its evolution during the cure has been measured for three widely used aerospace epoxy resins, namely, RTM6, 890RTM, and the XU3508/XB3473 system as function of cure temperature. A constitutive model expressing the dependence of thermal conductivity on the degree of cure and temperature has been established. The device developed here can measure thermal conductivity of epoxy resin with accuracy up to 3%. © 2018 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47015.
This paper is proposing and analyzing an electric energy storage system fully integrated with a photovoltaic PV module, composed by a set of lithium-iron-phosphate (LiFePO4) flat batteries, which constitutes a generation-storage PV unit. The batteries were surface-mounted on the back side of the PV module, distant from the PV backsheet, without exceeding the PV frame size. An additional low-emissivity sheet was introduced to shield the batteries from the backsheet thermal irradiance. The challenge addressed in this paper is to evaluate the PV cell temperature increase, due to the reduced thermal exchanges on the back of the module, and to estimate the temperature of the batteries, verifying their thermal constraints. Two one-dimensional (1D) thermal models, numerically implemented by using the thermal library of Simulink-Matlab accounting for all the heat exchanges, are here proposed: one related to the original PV module, the other related to the portion of the area of the PV module in correspondence of the proposed energy-storage system. Convective and radiative coefficients were then calculated in relation to different configurations and ambient conditions. The model validation has been carried out considering the PV module to be at the nominal operating cell temperature (NOCT), and by specific experimental measurements with a thermographic camera. Finally, appropriate models were used to evaluate the increasing cell batteries temperature in different environmental conditions.
Global solar radiation is generally measured on a horizontal surface, whereas the maximum amount of incident solar radiation is measured on an inclined surface. Over the last decade, a number of models were proposed for predicting solar radiation on inclined surfaces. These models have various scopes; applicability to specific surfaces, the requirement for special measuring equipment, or limitations in scope. To find the most suitable model for a given location the hourly outputs predicted by available models are compared with the field measurements of the given location. The main objective of this study is to review on the estimation of the most accurate model or models for estimating solar radiation components for a selected location, by testing various models available in the literature. To increase the amount of incident solar radiation on photovoltaic (PV) panels, the PV panels are mounted on tilted surfaces. This article also provides an up-to-date status of different optimum tilt angles that have been determined in various countries.
Present work deals with the topic of building integration of solar thermal collector (BIST) as a refurbishment measure. Such equipment, more than its main function as heating generator, plays a specific role as a building component (envelope finishes, thermal insulation layer, roof cover etc). Consequently, from a heat transfer point of view, an integrated component affects twice the global building balance: supporting the thermal plant (i.e. providing heat for final uses) and modifying the wall heat-transfer pattern (i.e. reducing thermal losses). In turn, the collector performance itself is influenced by the wall structure (back losses reduction). Present work proposes a method for evaluating the yearly performance of a low cost BIST by means of a Trnsys model on a reference building. This model arises from previous studies based on experimental validation of a FEM model that was implemented in order to describe the collector-wall system efficiency.
The thermal conductivity of epoxy resin composites filled with combustion-synthesized hexagonal boron nitride (h-BN) particles was investigated. The mixing of the composite constituents was carried out by either a dry method (involving no use of solvent) for low filler loadings or a solvent method (using acetone as solvent) for higher filler loadings. It was found that surface treatment of the h-BN particles using the silane 3-glycidoxypropyltrimethoxysilane (GPTMS) increases the thermal conductivity of the resultant composites in a lesser amount compared to the values reported by other studies. This was explained by the fact that the combustion synthesized h-BN particles contain less -OH or active sites on the surface, thus adsorbing less amounts of GPTMS. However, the thermal conductivity of the composites filled with the combustion synthesized h-BN was found to be comparable to that with commercially available h-BN reported in other studies. The thermal conductivity of the composites was found to be higher when larger h-BN particles were used. The thermal conductivity was also found to increase with increasing filler content to a maximum and then begin to decrease with further increases in this content. In addition to the effect of higher porosity at higher filler contents, more horizontally oriented h-BN particles formed at higher filler loadings (perhaps due to pressing during formation of the composites) were suggested to be a factor causing this decrease of the thermal conductivity. The measured thermal conductivities were compared to theoretical predictions based on the Nielsen and Lewis theory. The theoretical predictions were found to be lower than the experimental values at low filler contents (< 60 vol %) and became increasing higher than the experimental values at high filler contents (> 60 vol %).
Silica-epoxy nanocomposites are very common among nanocomposites, which makes them very important. Several researchers have studied the effect of nanoparticle’s size, shape, and loading on mechanical behavior of silica-epoxy nanocomposites. This paper reviews the most important research done on the effect of nanoparticle loading on mechanical properties of silica-epoxy nanocomposites. While the main focus is the tensile behavior of nanocomposite, the compressive behavior and flexural behavior were also reviewed. Finally, some of the published experimental data were combined in the graphs, using dimensionless parameters. Later, the best fitted curves were used to derive some empirical formulas for mechanical properties of silica-epoxy nanocomposites as functions of weight or volume fraction of nanoparticles.
In spite of ample natural and human resources, the north east region of India that consists of eight states is still lagging behind as compared to many states of India. People of these states are deprived in different socio-economic indicators. The aim of the paper is to examine the inequalities in socio-economic parameters of development, analyse inequality in the access to basic amenities, and quantify the level of facility and socio-economic deprivations. It was found that Multi-dimensional Poverty Index (MPI) value is highest in Assam but, inequality among the MPI poor is high in Meghalaya. In 2011-12, BPL population was highest in Manipur (46.7 %) followed by Assam (40.9 %) and Arunachal Pradesh (37.4 %) exceeding the all India level (29.5). It was observed that inequality is high in growth rate of population (%) (among demographic indicators), sanitation facilities (among the indicators of economic conditions), rail density (among indicators of infrastructure), average years of education, per capita monthly expenditure (Rs) and population Below Poverty Line. Analysis of access to basic amenities, namely, drinking water, toilet facility and electricity reveals the existence of wide state-level variations. Inequality in access to electricity is highest in urban sector as compared to the rural sector among the three basic services. Among the states of NER, the maximum average deprivation in the basic facilities is located in Meghalaya and the most Socio-economic deprived state is Nagaland. Thus, it is recommended for consistent and balanced development approach, expansion of capability, improvement in infrastructure and diversification of agriculture across the eight states of North East India.
The Indian Himalayan region is repository of abundance of natural resources such as water, land and forest. Varied landscapes – the valleys, mid-altitudes and the highlands comprise this region. Water potential, in the forms of glaciers, glacier-fed perennial rivers, highland lakes, springs and ground water is enormous and the whole Himalayan region is known as water tower. Economically viable forests from subtropical to temperate with high biodiversity characterise this region. These abundant natural resources are largely unused and as a result, economic status of the inhabitants is significantly low. Economy is mainly dependent on traditionally grown subsistence cereal crops with low output. Average Human Development Index is 0.561, people living below poverty line are 12.59 per cent, environmental sustainability index is 60-80 per cent and per capita income is Rs. 34029. This paper examines natural resources potentials and socioeconomic status in the Indian Himalayan region. Qualitative approach was applied to conduct this study. Data were mainly gathered from the secondary sources and through participatory observation method. This study reveals that the potential of natural resources is quite high. It further depicts that the optimum/sustainable utilization of available natural resources may enhance the livelihoods and economic sustainability. INTRODUCTION The Indian Himalayan Region (IHR) is endowed with abundance of natural resources in the forms of water, forest, fertile soil, pleasant climatic conditions and panoramic landscapes. Water potential such as glaciers, glacier-fed perennial rivers, the highland lakes, springs and ground water is abundant in the whole region. In terms of floral biodiversity, it is high in all altitudinal zones, comprises of subtropical to montane and temperate forests. The economic viability of these forests is significant. Alpine pasturelands/meadows are the repository of medicinal plants. The Himalayan region comprises of lofty snow clad mountain peaks, river valleys, alpine pastures and dense forest covers. Landscape is fragile and highly vulnerable to natural hazards. Agricultural practices are the main occupation and the major source of income. Meanwhile, the output from these traditionally grown cereal crops is less. Farming system varies from terraced cultivation in the western and central Himalaya to shifting cultivation in the eastern and eastern extension of the Himalaya. Environmental conditions are sound, as the environmental sustainability index (ESI) is 60-80 per cent. Literacy rate is also very high (78.73 per cent). The two peculiar situations are existed i.e. the rich land: presence of high economically viable natural resources; and the poor people: socially backward and economically underdeveloped. However, the whole Himalayan region consists of the high cultural, ethnic and biological diversity. In this region, about 171 schedule tribes are inhabited, which represents 29.8 per cent of the total tribal population of India (Samal et al., 2000). The landscape, climatic conditions, socio-economy and cultural status of this region varies from the western to central, eastern and eastern extension of the Himalaya. Meanwhile, the whole Himalayan region is underdeveloped. Furthermore, the infrastructural facilities are lagged behind. Human
The 2013 Special Issue of Australian Journal of Chemistry highlights papers on the current state of research in the field of coordination polymer and indicates briefly where some of the future challenges and opportunities in the field may lie. Coordination polymers, which are also widely known as metalorganic frameworks (MOFs), are infinite solid-state networks that can be synthesized from combinations of organic links and metals or metal oxide clusters. In their full paper, Hawes and Kruger report the structural diversity that can be observed when flexible linkers are employed. As part of a series of papers on silver(I) coordination networks, Mak and coworkers report the synthesis of organosilver(I) framework based on underexplored multinuclear heteroaryl ethynide supramolecular synthons. Neville and co-workers report the magnetic properties of a family of 3-D coordination polymers based on the three-connecting ligands 2,4,6 tris(3-pyridyl)-1,3,5-triazine (3-tpt) or 2,4,6 tris(4-pyridyl)-1,3,5-triazine (3-tpt).
The solar energy photovoltaic thermal system is a method to achieve grade utilization of solar energy to improve the comprehensive utilization efficiency of energy. A kind of solar energy photovoltaic air conditioning wall is put forward in this paper, adopting the air flow channel with a small hole on the surface and the negative pressure inside, which can provide electricity and hot air heating simultaneously. The comparison test of the solar photovoltaic cells components (PV) and the solar photovoltaic air conditioning wall (PV/T) shows, under the condition that the radiation intensity reaches above 700W/m²，and the ambient temperature exceeds 25°C, the temperature of PV/T components is slightly higher than PV components, so the power generating efficiency decreases slightly, with the average generating efficiency 12.51%, while the efficiency of the PV is 12.96%.each square meter of the solar energy photovoltaic air conditioning wall can provide the building with 40 m³ of fresh air per hour, with 20°C higher than outdoor, so the average photo-thermal efficiency is 39%.If the photovoltaic air conditioning wall is installed on outside surface of the building envelope, or replace it, to built the building integrated photovoltaic solar thermal system, the building energy consumption would greatly reduce.
This article is designed to review the developments in synthesis, modifications, and properties of epoxy monomers derived from both petroleum and renewable resources. It begins with the enhancement in epoxy monomer properties such as mechanical, thermal, adhesive, barrier and etc by addition of flexible polymer and elastomers. It also explains the role of organic/inorganic fillers on epoxy monomers to achieve the desired properties for outdoor applications. The effect chemical/physical treatments on fiber are reviewed and their improvements with epoxy monomers also observed. Authors also suggested for further improvement of epoxy monomers for various eco-friendly high performance applications.
While sheet-and-tube absorber is generally recommended for flat-plate photovoltaic/thermal (PV/T) collector design because of the simplicity and promising performance, the use of rectangular-channel absorber is also tested to be a good alternative. Before a new energy technology, like PV/T, is fully implemented, its environmental superiority over the competing options should be assessed, for instance, by evaluating its consumption levels throughout its production and service life. Although there have been a plenty of environmental life-cycle assessments on the domestic solar hot water systems and PV systems, the related works on hybrid solar PV/T systems have been very few. So far there is no reported work on the assessment of PV/T collector with channel-type absorber design. This paper reports an evaluation of the energy payback time and the greenhouse gas payback time of free-standing and building-integrated PV/T systems in Hong Kong. This is based on two case studies of PV/T collectors with modular channel-type aluminium absorbers. The results confirm the long-term environmental benefits of PV/T applications.
Both air and water cooled PV/T collectors have enjoyed growing attentions in recent years. Investigators have reported PV/T research data within a wide range of control parameters. In this paper, the effects of the major control parameters on the thermal/electrical performance of PV/T collectors are compiled and reviewed. Figures and tables are provided to give an overall picture about how PV/T performance could be improved in terms of these parameters. Although investigators understand the effects of different param- eters, the improvement of PV/T performance by optimizing these parameters has not been fully realized.
The conceptualized non-contact Photovoltaic-Thermal (PV-T) collector consists of a PV panel separated by a conventional sheet
and tube solar thermal collector. Simulation of both non-contact type and contact type collectors is carried out and correlations
are proposed for both thermal and electrical efficiencies in terms of irradiation, inlet water temperature, ambient temperature
and PV transmissivity. At high values of transmissivity (τ > 0.75), the thermal efficiency of the non-contact type system
exceeds that of the contact type collector at higher values of inlet temperatures. The PV-T system yields thermal and electrical
efficiencies in the order of 30–35% and 8–9% respectively. Experiments are carried out to validate the simulation results
and to study the infl uence of performance parameters. It is found that non-contact type collectors can perform better than
the contact type collectors at high water inlet temperatures and high PV panel transmissivity values.
The performance of an improved double-pass hybrid photovoltaic-thermal (PV/T) solar air heater is analyzed in the present work. Hybrid photovoltaic thermal systems overcome the limitations of simple photovoltaic systems. A detailed analytical study was performed under steady state conditions. The various performance parameters like temperature rise of air, electrical efficiency, thermal efficiency, energy efficiency of hybrid system, exergy efficiency, etc. were determined. The improved PV/T system showed a better performance compared with the base model PV/T air heater. Electrical efficiency of the base model PV/T air heater varies from 6.49 –7.65 % while it varies from 7.82- 9.82% in the case of a PV/T system with slats attached to the absorber due to better heat dissipation. Energy efficiency of the PV/T system without slats varies from 36.34 to 39.65% while for the PV/T with slats it is between 52.57 and 58.24%.
Short term forecasting of solar radiation is useful for power plant operations, grid balancing, real-time unit dispatching, automatic generation control and trading. Solar forecasting is an essential tool in solar PV power plant to improve quality of energy delivery to the grid and to reduce weather dependent ancillary costs. In this paper short term forecasting of solar radiation and power output of 89.6 kWp solar PV power plant has been conducted. A new model has been proposed to conduct short term solar forecasting for different days of the year at Amity University Haryana (AUH) campus (28.4595°N, 77.0266°E) located in the northern region of India whereas auto-regressive integrated moving average (ARIMA) model is applied to forecast power output from the solar PV power plant. Root mean square error (RMSE) and Forecast Score (FS) has been used to for accessing the quality of forecasting models.
The proposed model for prediction of solar radiation on tilted surface is simple and has very high accuracy. The model has ability to incorporate uncertainty due to environmental conditions. The proposed model is compared with Smart Persistence model and ARIMA model and it has been observed that it has better RMSE and Forecast Score than both Smart Persistence model and ARIMA model for both 15 min and 30 min time horizon.
ARIMA model provides a reliable forecast for both solar radiation and solar PV power output. It is flexible enough to accept more information and its performance improves with the increase in number of data points.
Combination of Photovoltaic (PV) and solar thermal collectors is used for the simultaneous production of electricity and heat. The proposed research work evaluates the thermal performance of Photovoltaic/Thermal (PV/T) hybrid collectors for the hot and humid weather condition of North Tamilnadu, South India. It is done by providing the cooling arrangement under the collector using wooden duct with baffles. Various parameters influencing the performance of the collector such as solar irradiance, ambient, glazing & tedlar temperatures, air inlet and outlet temperatures at the duct, velocity and mass flow rate of air inside the duct are analyzed. The thermal and electrical performance of the PV/T collectors are evaluated under natural and forced circulation of air through the thermal collector. The experimental results are presented in this paper.
In this study, we report a facile approach to fabricate epoxy composite incorporated with silicon carbide nanowires (SiC NWs). The thermal conductivity of epoxy/SiC NWs composites was thoroughly investigated. The thermal conductivity of epoxy/SiC NWs composites with 3.0 wt% filler reached 0.449 Wm⁻¹ K⁻¹, approximately a 106% enhancement as compared to neat epoxy. In contrast, the same mass fraction of silicon carbide micron particles (SiC MPs) incorporated into epoxy matrix showed less improvement on thermal conduction properties. This is attributed to the formation of effective heat conduction pathways among SiC NWs as well as a strong interaction between the nanowires and epoxy matrix. In addition, the thermal properties of epoxy/SiC NWs composites were also improved. These results demonstrate that we developed a novel approach to enhance the thermal conductivity of the polymer composites which meet the requirement for the rapid development of the electronic devices.
The higher penetration of renewable resources in the energy portfolios of several communities accentuates the need for accurate forecasting of variable resources (solar, wind, tidal) at several different temporal scales in order to achieve power grid balance. Solar generation technologies have experienced strong energy market growth in the past few years, with corresponding increase in local grid penetration rates. As is the case with wind, the solar resource at the ground level is highly variable mostly due to cloud cover variability, atmospheric aerosol levels, and indirectly and to a lesser extent, participating gases in the atmosphere. The inherent variability of solar generation at higher grid penetration levels poses problems associated with the cost of reserves, dispatchable and ancillary generation, and grid reliability in general. As a result, high accuracy forecast systems are required for multiple time horizons that are associated with regulation, dispatching, scheduling and unit commitment. Here we review the theory behind these forecasting methodologies, and a number of successful applications of solar forecasting methods for both the solar resource and the power output of solar plants at the utility scale level.
This work focuses on the performance analysis of a photovoltaic (PV)–thermal collector, regarding parameters like number and location of PV cells, inlet fluid temperature, irradiation level and ambient temperature. This is accomplished through the numerical solving of a developed 2D mathematical model of the collector. A hybrid flat plate and tube collector is considered for the study, using water as thermal fluid. The results are a contribution to a better design of hybrid solar collectors, namely when the PV cell area is smaller than total collector area, which is the case in many practical applications. Specific conclusions point to a linear decrease in global efficiency with the increase in PV cell area and to a small change in global efficiency with the location of cells (either at the inlet or outlet collector zones).
To investigate the effect of the large-scale adoption of photovoltaic (PV) systems on the national electricity transmission network, an appropriate represent-ation of solar radiation is a very important factor, since this dictates the power output of the PV systems. This paper discusses the generation of synthetic radiation values at hourly intervals that can represent both the variability and the average solar flux obtained in practice. The use of the Markov Transition Matrix (MTM) method to generate hourly global horizontal radiation series for different locations in the UK is described. The method of preparation of the MTM and the comparison of generated and measured data are presented. A preliminary study on the temporal correlation of insolation between locations is also discussed.
In a recent research and development project a novel prototype pultruded composite structure was designed, fabricated, and tested. The bargelike, box-girder type structure measured approximately 24-ft long by 15-ft wide by 5-ft high (7.3 3 4.6 3 1.5 m). The structure was constructed from commercially available off- the-shelf pultruded structural profiles and panel sections. Tubular steel structural members and steel hardware were used to connect and join the different sections and subassemblies. The structure consisted of three 24-ft- long by 5-ft-wide by 5-ft-high (7.3 3 1.5 3 1.5 m) rectangular box-girder modular units and six 4-ft (1.2-m) wide modular deck panels. A design requirement was that the structure be capable of being transported by conventional, nonpermit trucking and be assembled at a remote site for subsequent testing. The structure was fabricated at a ship building and repair shop in Norfolk, Va., whose primary expertise was with conventional steel ship-structure fabrication methods and which had no prior experience with fabricating a large pultruded structural system. To fabricate and assemble the structure, a set of construction documents was produced. These included a set of written construction and assembly specifications, a set of detailed construction drawings, a detailed parts list, and a schedule. This case study details the construction process and provides a step-by-step explanation of how the engineering design team developed the construction documents for a relatively complex pultruded composite structure. Details of the design, analysis, and testing of the system are provided elsewhere.
Hybrid photovoltaic-thermal (PV-T) solar collectors are used to simultaneously obtain electricity and heat from the same collector. For the same energy output, the combined collectors lead to a lower total area than separate thermal and PV collectors. Numerical models were developed for two types of hybrid collectors, with a flat-plate and tube geometry: one using monocrystalline silicon (mono-Si) PV cells and one using amorphous silicon (a-Si) flexible PV cells. The electrical, thermal and total efficiency characteristics of both types were quantified. Application of the hybrid collectors to a system generating electricity and hot water was analysed, considering two building types: a residential building and a hotel. The electrical and thermal energies produced annually, as well as the amount of backup energy, were calculated by means of the SolTerm energy simulation program for the climatic conditions of Porto, Lisbon, Faro and Bragança (Portugal). An economical analysis was carried out by comparing the hybrid system with a conventional energy system and with a system with thermal collectors and PV modules installed separately. Finally, the environmental impact of the hybrid system was assessed and compared with a conventional energy system.
The failure process arising at a broken fibre end in polymer matrix composite materials has been studied experimentally and analytically using the finite element method. A series of experiments were carried out using S-glass and E-glass single filaments, with different sizings and/or coupling agents, embedded in epoxy matrices with different moduli. A finite element analysis was used to simulate the experiments and calculate the change in strain energy accompanying the observed fracture mode. The strain energy release rate upon arrest of the crack, G
arrest, was then calculated. The measured interface debonding energies varied from G
arrest=57–342 J m–2, depending primarily on the nature of the fibre sizing and the ratio of moduli of the fibre and matrix. Transverse and shear matrix cracks were characterized by G
arrest values of 58–103 J m–2. Subtle changes in the constituent properties or fibre surface treatment resulted in a change in the fracture mode. This measurement and analysis technique may suggest reasons for the variability of previous measurements of interfacial adhesion, and provide a standard method for characterizing fracture modes at broken fibre ends.
The photovoltaic (PV) cells suffer efficiency drop as their operating temperature increases especially under high insolation levels and cooling is beneficial. Air-cooling, either by forced or natural flow, presents a non-expensive and simple method of PV cooling and the solar preheated air could be utilized in built, industrial and agricultural sectors. However, systems with heat extraction by air circulation are limited in their thermal performance due to the low density, the small volumetric heat capacity and the small thermal conductivity of air and measures for heat transfer augmentation is necessary. This paper presents the use of a suspended thin flat metallic sheet at the middle or fins at the back wall of an air duct as heat transfer augmentations in an air-cooled photovoltaic/thermal (PV/T) solar collector to improve its overall performance. The steady-state thermal efficiencies of the modified systems are compared with those of typical PV/T air system. Daily temperature profiles of the outlet air, the PV rear surface and channel back wall are presented confirming the contribution of the modifications in increasing system electrical and thermal outputs. These techniques are anticipated to contribute towards wider applications of PV systems due to the increased overall efficiency.
Climate Change in Northeast India: Recent Facts and Events- Worry for Agricultural Management
- A Das
- P K Ghosh
- B U Choudhury
- D P Patel
- G C Munda
- S V Ngachan
- P Chowdhury
- Das A.
Modeling and Testing of a Solar Energy Intensifier System
- R M Polak
- Polak R. M.
Solar Energy-Principles of thermal collection and storage. 3 edition, Tata McGraw Hill Education Private limited
- S P Sukhatme
- J K Nayak
Indigenous technology knowledge for watershed management in upper north-west Himalayas of India (GCP/RAS/161/NET)
- L R Verma