Thermodynamic Analysis And Experiment For Combined Power And Refrigeration Cycles For Low Temperature Heat Sources

Low temperature heat sources refer to low grade heat sources including solar energy, waste heat, geothermal energy and ocean thermal energy. Recently many scholars pay a lot attentions on how to use these low temperature heat sources efficiently. Base on the studies of these scholars, this dissertation analyse the thermodynamic performance and do experiment on a new type combined power and refrigeration cycles for low temperature heat sources. Main contents are included as follows:(1) Introduce the composition and working principle of a new type combined power and refrigeration cycle for low temperature heat sources. Especilly focus on the expander and ejector. Select the scroll expander as the system output device. Due to improve the quality of power, this dissertation pay some attentions on the power transformation device, using the EMTP software to simulate the power transformation device. Meanwhile this dissertation also analyse the working fluid through thermodynamics properties and comprehensive environmental performance and it is concluded that the working fluids with high critical temprature (R245fa,R123,R600a) can be the alternative working fluids for combined cycle.(2) Analyse the thermodynamic performance for the basic combined power and refrigeration cycle for low temperature heat sources and caculate the performance parameters and all the state points parameters of the system on standard condition. It is conclude that the thermal efficiency is 36.85% and the correction efficiency is 15%. In addition, this dissertation also analyse the effects of key parameters on cycle performance. (3) Analyse the thermodynamic performances for the heat recovery type and reheat type combined power and refrigeration cycles for low temperature heat sources and caculate the performance parameters and all the state points parameters of the system on standard condition. Analyse the effects of key parameters on these cycle performances.(4) Introduce the experimental prototype of combined power and refrigeration cycle for low temperature heat sources and the main devices. Make experiments on power generation cycle, refrigeration cycle and combined power and refrigeration cycle. Analyse the experimental datas. By changing the heat source temperatures and frequency of pump, analyse the changing parameters of the influence on the performance of the system.