工质对以低温余热蒸汽为热源的ORC系统热力性能影响  

Influence of the Working Medium on the Thermodynamic Performance of an ORC(Organic Rankine Cycle) System With Low Temperature Waste Heat-produced Steam Serving as the Heat Source

作　　者：杨新乐[1] 赵阳升[2] 戴文智[1] 任常在[1] 

机构地区：[1]辽宁工程技术大学机械工程学院,辽宁阜新123000 [2]太原理工大学采矿工艺研究所,山西太原030024

出　　处：《热能动力工程》2013年第2期139-144,215-216,共6页Journal of Engineering for Thermal Energy and Power

基　　金：国家自然科学基金重点基金资助项目(50534030);国家自然科学青年基金资助项目(51104083)

摘　　要：为回收利用矿藏热采过程中产生的低温余热蒸汽,提出利用有机朗肯循环(ORC)系统进行热力发电。以自主研制的对流热采油页岩低温余热发电实验系统参数为依据,选用5种环保工质,通过编制计算程序模拟分析了不同工质对ORC系统热力性能影响规律。计算模拟结果表明:各工质均只能以亚临界状态运行,系统热效率和净输出功率随蒸发压力的提升呈现单调递增和增幅减小的趋势,采用工质R236fa可获得最高蒸发压力1.94 MPa,工质R600可得到最高净输出功率和热效率分别为4.211 kW和11.1%,R236fa,R600和R114由于系统运行蒸发压力较大而产生较大的净输出功率及获得较高的热效率;系统火用效率随蒸发压力变化规律与热效率变化规律类似,R600火用效率最高可达45.98%,提高蒸发压力可有效提高系统火用效率,减小系统火用损失;从乏气冷凝难易角度认为R245fa和R123是ORC系统较为合适的工质。To recover and utilize the steam produced from low temperature waste heat during the hot exploitation of mineral resources,proposed was an organic Rankine cycle-based thermal power generation system.With the parameters of a self-developed convection hot production oil shale low temperature waste heat power generation test system serving as the basis,five environmentally-protected working media were chosen.Through utilizing the calculation program designed,the law governing the influence of different working media on the thermodynamic performance of the system was simulated and analyzed.The calculation and simulation results show that each working medium can work only in the subcritical state,the thermal efficiency and net output power of the system will assume a monotone increase and decreasing increment tendency with an increase of the evaporation pressure.To use R236fa can obtain the highest evaporation pressure of 1.94 MPa while to use R600 can get the highest net power output and thermal efficiency of 4.211 kW and 11.1% respectively.Due to a relatively high evaporation pressure permitted by the system when R236fa,R600 and R114 are used,a relatively big net power output can be produced with a relatively high thermal efficiency.The variation law of the exgergy efficiency of the system with the evaporation pressure is similar to that of the thermal efficiency.The exergy efficiency of the system when R600 is used can hit the highest of 45.98%.To raise the evaporation pressure can effectively enhance the exgergy efficiency of the system and decrease the exergy loss of the system.From the viewpoint of the difficulty of the exhaust steam to be condensed,the authors believe that R245fa and R123 should be the working media applicable for organic Rankine cycle systems.

关 键 词：有机工质 低温余热蒸汽 有机朗肯循环 热力性能 

分 类 号：TK11[动力工程及工程热物理—热能工程]