低温地热发电有机朗肯循环的优化

采用(火用)分析方法及PR状态方程,建立了低温地热发电有机朗肯循环的工质优选及主要参数优化热力学方法.比较计算了以10种干流体有机工质为循环工质的低温地热发电有机朗肯循环的输出功率、(火用)效率及其余主要热力性能.结果表明,低温地热发电有机朗肯循环的性能极大地受工质的物性及蒸发温度的影响.总体来看,随着工质临界温度的升...

Optimization of the Low-temperature Geothermal Heat Powered Organic Rankine Cycle

The exergetic analysis method and PR equation of state were utilized to establish the thermodynamic method of working fluid se- lection and the optimization of the low-temperature geothermal heat powered organic Rankine cycles. Thermal performances, including power output, exergy efficiency, etc. of low-temperature geothermal heat powered organic Rankine cycles using 10 kinds of dry fluids as working fluids, were calculated and eompared. The results show that： The performances oflow-temperature geothermal heat powered organic Rankine cycle are greatly affected by evaporation temperature and working fluid＇ s thermal properties. As the critical temperature of working fluid in- creases, the output power and exergy efficiency show a decreasing trend, but the cycle thermal efficiency and the final discharge （or rejection） temperature of the geothermal fluid show an increasing trend as a whole. Moreover, the organic Rankine cycle charged with R227ea （hepta- fluoropropane） gets the highest power output and exergy efficiency, and the evaporation and condensation pressures are in the appropriate range, therefore, R227ea appears to be the ideal working fluid for low-temperature geothermal heat powered organic Rankine cycles. There exists an optimal evaporation temperature, at which the output power and exergy efficiency of the low-temperature geothermal heat powered organic Rankine cycle get the maximum.