Figure 4 - uploaded by Daniel Favrat
Content may be subject to copyright.
Source publication
This paper presents field tests of an original concept of a small hybrid solar power plant integrating three technologies: hermetic volumetric scroll expander-generators installed in two superposed Organic Rankine Cycles (ORC), a (bio-)Diesel engine with heat recovery exchangers and a solar field made of two rows of sun following flat plate concent...
Contexts in source publication
Context 1
... fact, as it can be noticed in figure 3 and 4, the temperature difference between condensation and evaporation stage in this exchanger is about 20°C which is much too high. This can partly be explained by the large amount of oil mixed with the evaporating working fluid (134a), whose boiling temperature strongly increases in the dryout region of the evaporator (non linearity not represented in Figure 4). ...
Similar publications
This article aims at finding the most suitable waste heat recovery technology for existing and future offshore facilities. The technologies considered in this work are the steam Rankine cycle, the air bottoming cycle and the organic Rankine cycle.
A multi-objective optimization approach is employed to attain optimal designs for each bottoming unit...
Waste heat recovery is an effective method for improving engine efficiency. While most research on waste heat recovery from heavy-duty engines focuses on the high-temperature heat sources, this paper investigates the performance of a low-temperature system. The experimental setup features an organic Rankine cycle with R1233zd(E) as the working flui...
The performance of a 300 kW organic Rankine cycle (ORC) prototype was experimentally investigated for low-grade waste heat recovery in industry. The prototype employed a specially developed single-stage radial turbine that was integrated with a semi-hermetic three-phase asynchronous generator. R245fa was selected as the working fluid and hot water...
Currently, internal combustion engines (ICEs) are still the main power for transportation. Energy conservation and emission reduction for ICEs have become the driving force of the industrial R&D in recent years. Organic Rankine cycle (ORC) is a feasible technology to recover the waste heat of an ICE so that the energy efficiency can be enhanced app...
Renewable Energy Investment triggering a debate on clean energy Vs conventional energy. The house of conventional energy i.e. Coal Mines which are abandoned can be serve as a green and clean energy option for the world. Abandoned and flooded coal mines have good potential as low enthalpy geothermal resources, which could be used for small to medium...
Citations
... When used, the power range of il\e engine varied between 11 and 13 kWe, due in particular to variations in the air aemperaflue, and gave a heat recovery of the order of 20 kWth on the engine block and 7 kWth on the exhaust gases. For all tests covering a cumulated duration of 110 hours, the power plant produced about 800 rThe approach is part of iglobal methodology developped in a recent thesis (Kane, 2002) for the systemic optimisation of hybrid thermal solar power plants in general. ...
... The tests of the SPS prototype allowed the identiFrcation and model validation of the most significant operational patameters (Kane, 2002). However the actual size of the different components (motor, turbine) as well as the type and number of installed turbines ar9 not optimal when considering the yearly operation. ...
A new concept of small hybrid solar power system (HSPS) has been successfully demonstrated in the context of a project called SPS (Solar Power System). This plant integrates two rows of solar collectors, two superposed Organic Rankine Cycles (ORC) each equipped with a scroll hermetic expander-generator and a heat engine. In operation with solar energy only, the heat is supplied by a thermal fluid (presently pressurized water) heated in the vacuum insulated focal tubes of sun following, flat concentrators made of series of thin plate mirrors (CEP). In hybrid mode additional heat is supplied by heat recovery from the exhaust gases of the engine in series with the solar network and by a separate network recovering heat from the cooling of the engine block at an intermediate temperature level. This paper presents the results of a multi-criteria optimization of a 22 kWe HSPS, including aspects such as energy performance, economic and financial analysis, and environemental aspects. The so called mini-maxi methodological approach with genetic algorithm is used considering three principal criteria such as the energy efficiency of the superposed ORCs, the minimal cost of the installation and the minimum emission of CO2 . Taking into account of the solar radiation time dependence, the elecricity supply variation and the change of configuration (night and day operation), the performance analysis is based essentially on the yearly energy simulation in which the off-design physical models of components are considered. A comparison of HSPS with pure fossil fuelled Plants (DEPU-Diesel Engine Power Unit) is reported for the same electrical power load curve, with an economic sensitivity analysis. Results show that the solar electricity costs are still high and depend considerably on the size of the Solar Field (the HSPS Levelized Electricity Cost with 5 to 16% of annual solar share is about 17% to 49% higher than a similar size Diesel Engine Power Unit). However, a reduction of CO2, emission up to 26% could be obtained when replacing the Diesel Engine Unit by a similar HSPS. Those hybrid solar thermal power systems may already be competitive if a tax of about 42 Swiss cts/kgCO2 would be considered.
