Combined Ejector Refrigeraiton And Low-Grade Energy Recovery System Application

Energy conservation is the mainstream research of the world. Research and development on power generation and refrigeration from low-grade energy, such as solar energy, geothermal energy, and other low-grade industrial waste energies is one of the important direction.Basic structure and working principle of refrigeration and power generation system, with ejector and expander in parallel. Then, selected R290, R600a, R1234yf, R1234ze(E) etc. as the working fluid of the cycle. And a thermodynamic model of the system was established. Analyzed the performances of system with different working fluids. Next, analyzed two enhanced ejector refrigeration system:basic enhanced ejector refrigeration system(EERS) and Rankine-compressor-ejector refrigeration system(RCERS). Compared with the RCERS, the EERS had low the total refrigerant mass flow, low heat consumption, low pump power consumption, and high coefficient of performance (COP) for overall system. However, the overall system power consumption of EERS was much higher than RCERS, and the mechanical coefficient of performance(COPm) of EERS was much lower than the RCERS. In the basis, pressure energy recovery enhanced ejector refrigeration system(PEERS) were designed. Compared with pure single-stage ejector refrigeration system, the COP of PEERS increased by an average of more than 10%.An ejector refrigeration and power generation system designed, combined with a 200,000 tons of acrylonitrile project, Guangxi, recycling cold energy of raw materials in feeding section of acrylonitrile production and low waste heat. Propane was selected as the working fluid. The thermal efficiency and the exergy efficiency of the proposed combined system are 19.1% and 49.8%, respectively. In addition, the results show that the performance of the combined system could benefit from increasing generation pressure, increasing superheat and decreasing condensing temperature.