喷射器对地热有机朗肯循环发电系统性能的影响  

Influence of a Jet Ejector on the Performance of a Geothermal Organic Rankine Cycle Power Generation System

作　　者：彭继慎[1] 鲁广栋 宋立业[1] 李逃昌[1] 

机构地区：[1]辽宁工程技术大学电气与控制工程学院,辽宁葫芦岛125105

出　　处：《热能动力工程》2016年第7期30-35,132,共6页Journal of Engineering for Thermal Energy and Power

基　　金：辽宁省教育厅创新团队项目(LTJ2011101;LT2010047)

摘　　要：为了缓解由于冷凝温度较高带来的高背压问题,提出一种带喷射器的ORC(有机朗肯循环)发电系统。针对373 K地热热源,分析了不同工质及冷凝温度下,喷射器对系统性能的影响,并将其在有/无分流2种工况下进行比较。结果表明:采用喷射装置可提高系统性能,存在一最佳升压比a使系统性能最大,其中ORC-分流喷射系统>ORC-喷射系统>ORC系统,若以R245fa为工质,在Tc=298 K时,经分流喷射的系统较喷射ORC及ORC系统火用效率分别高出1.89%和6.43%。工质临界温度越高,采用喷射装置对系统性能提高越大,通过分流可以削弱工质对喷射装置的影响,使其更接近ORC系统的工质表现规律:R236fa>R114>R245fa>R152a。当系统冷凝温度较高时,采用喷射装置具有重要意义。In order to lessen the high back pressure problems arisen from a relatively high condensation temperature,proposed was an ORC power generation system. For a geothermal heat source at a temperature of 373 K,the influence of the jet ejector on the performance of the system was analyzed under various working media at different condensation temperatures and a comparison was made under the following two operating conditions,one having a flow division and another having not. It has been found that the use of a jet ejector device can enhance the performance of the system and an optimum boosting pressure ratio a does exist to make it be the best,among them,an ORC-based flow division jet ejector system > an ORC-jet ejector system > an ORC cycle system. If R245 fa serves as the working medium and when Tc = 298 K,the flow division jet ejector system will have a higher exergy efficiency than the jet ejector ORC system and the ORC cycle system by 1. 89 % and 6. 43% respectively. The higher the critical temperature of the working medium,the better in enhancing the performance of the system using the jet ejector device. The flow division can lessen the influence of the working medium on the jet ejector device,thus making the law governing the system efficiency when various media is used closer to that of the ORC cycle system: R236 fa > R114 >R245fa > R152 a. When the condensation temperature of the systems is comparatively high,the use of a jet ejecto rdevice has an important significance.

关 键 词：喷射器 冷凝温度 最佳升压比 临界温度 系统性能 

分 类 号：TM611.3[电气工程—电力系统及自动化]