工业余热MW级ORC发电机组[火用]分析

Exergy analysis of industrial waste heat MW-level ORC power generation unit

为了探究有机朗肯循环(ORC)实际发电系统各个设备的[火用]效率和[火用]损失情况以及影响系统[火用]效率的因素,以上海某工业园区厂用余热MW级ORC发电机组为对象,利用Refprop 9.1等工具对机组有机朗肯循环热力过程中冷热源和循环工质状态点实际参数进行[火用]分析。通过确定蒸发器、透平机、冷凝器、工质泵等主要部件的能量转换效果和有效利用程度,分析系统[火用]效率与部件[火用]效率的关系,提出系统性能改进优化方向。结果表明:透平机[火用]效率最高,可达75%;冷凝器[火用]效率最低,基本在25%以下。蒸发器(包括热水蒸发器和蒸汽蒸发器)[火用]损失占比最大,达到71%,其次是冷凝器和透平机,分别为20%和8%,工质泵[火用]损失占比最小,仅为1%。系统[火用]效率受蒸发器[火用]效率影响,随着蒸发器[火用]效率的提升,系统[火用]效率也会有所增加。因此,提高蒸发器和冷凝器的[火用]效率,同时降低蒸发器的[火用]损失是减小系统能量损失的关键。

In order to explore the exergy efficiency and exergy loss of each device of ORC(organic Rankine cycle)actual power generation system and factors that influence the system exergy efficiency,taking the MW-level ORC power generation unit in an industrial park in Shanghai as object.Using Refprop 9.1 and other tools to conduct exergy analysis on actual state parameters of cold and heat sources and circulating working fluid in the thermal process of the organic Rankine cycle of the unit.By determining the energy conversion effect and effective utilization degree of the main components such as evaporator,turbine,condenser,working fluid pump,etc.,the relationship between the system exergy efficiency and the component exergy efficiency is analyzed,and the optimization direction for system performance improvement is proposed.The results show that the exergy efficiency of the turbine is the highest,reaching more than 75%,and the exergy efficiency of the condenser is the lowest,basically below 25%.The exergy loss of the evaporator including hot water evaporator and steam-heated evaporator accounts for the largest proportion,reaching 71%,followed by the condenser and turbine,20%and 8%respectively,and the exergy loss of the working fluid pump is the smallest,only 1%.The exergy efficiency of the system is affected by the exergy efficiency of the evaporator.As the exergy efficiency of the evaporator increases,the exergy efficiency of the system will increase to a certain degree.Therefore,improving the exergy efficiency of the evaporator and the condenser while reducing the exergy loss of the evaporator is a key to reducing the energy loss of the system.