ORC发电系统变热源温度实验研究

Experimental Study on Variable Heat Source Temperature for ORC Power Generation System

为研究有机朗肯循环(ORC)热源温度变化引起的循环热效率、(火用)效率、发电效率等性能的变化情况,搭建以R245fa为循环工质的ORC发电系统实验平台。实验结果表明:热源温度的提高使循环蒸发压力、冷凝压力升高,膨胀机入口温度、压力升高,膨胀比增大,等熵效率提升,膨胀做功能力增强,系统循环热效率、(火用)效率、发电效率均增大;在冷源温度为12℃,工质流量保持恒定的情况下,热源温度从87.5℃上升至108.1℃时,循环热效率由4.1%提升到7.1%,系统(火用)效率由17.2%提升到30.0%,系统发电效率由4.1%提升到7.3%。

Organic Rankine cycle has the characteristics of using effectively organic working substance to absorb low temperature heat sources such as solar energy and geothermal energy and transform them into electrical energy.In order to study the changes of cyclic thermal efficiency,exergy efficiency and power generation efficiency caused by the change of heat source temperature in the organic Rankine cycle power generation system,an experimental platform for ORC power generation system is built using R245fa as working fluid.The results show that with the increase in the heat source temperature,the evaporation pressure and condensation pressure increases,and the inlet temperature and pressure of the expander,the expansion ratio,and the isentropic efficiency also increase,and the work ability of expander is enhanced.As a result,the cycle thermal efficiency,exergy efficiency and power generation efficiency of the system are improved.Under the condition that the cold source temperature is 12℃and the refrigerant flow is constant,the cycle thermal efficiency is increased from 4.1%to 7.1%,the system efficiency is increased from 17.2%to 30%,and the power generation efficiency of the system is increased from 4.1%to 7.3%as the heat source temperature rises from 87.5℃to 108.1℃.