分布式小型有机朗肯循环运行特性实验

Flexible operating characteristics of an organic Rankine cycle for distributed energy system

针对分布式能源系统中可利用热源的温度和流量频繁波动的特点,测试了kW级有机朗肯循环原型机组在110~150℃波动热源下的运行性能和以工质流量与膨胀机转速为控制变量的多工况运行能力。结果表明,通过调节工质流量可以在相对平稳的热效率下实现对机组输出功率的有效控制。机组输出功率随热源温度变化剧烈,但随热源流量变化规律不一:小工质流量下,换热面积冗余较多,热源流量的变化对机组性能的影响可以忽略;随着工质流量的提高,热源流量的影响逐渐凸显,表现为机组性能随工质流量下降而明显降低。机组在热源温度150℃下获得最大输出功约4 kW,最大热效率6.0%。

In view of the frequent fluctuation of temperature and flow rate of the available heat source in distributed energy system,the performance of the kW-scale organic Rankine cycle prototype with fluctuating heat source of 110~150 ℃ was tested and its multi-condition operation characteristics with the working fluid flow rate and expander rotary speed as the control variables was analyzed.The results showed that,the fluid mass flow rate was an effective control parameter to adjust the shaft power while maintaining the relatively stable system thermal efficiency.The shaft power was sensitive to the variation of heat source temperature while it exhibited different trends with the heat source mass flow rate.When the fluid mass flow rate was relatively small,there was enough redundancy in the heat transfer area.Under this condition,the heat source flow rate had quite weak effect on the ORC performance.With an increase in the fluid flow rate,the effect of heat source flow rate emerged.The ORC performance was deteriorated with the reducing heat source flow rate.The maximum shaft power and thermal efficiency of 4 kW and 6.0% could be achieved at the heat source temperature of 150 ℃.