海上油气平台余热朗肯循环发电系统热力学分析

海上油气平台存在大量的燃气轮机余热。通过建立海上平台余热朗肯循环发电系统仿真模型,开展平台余热发电热力学及热经济性分析。选取工质泵功率、发电机输出功率、系统热效率、换热面积和单位面积发电量等参数作为优化目标,研究不同冷凝温度下优化目标函数随蒸发器烟气进出口温差的变化规律。结果表明:随着蒸发器烟气进出口温差的增加,工质泵功率、发电机输出功率和系统APR先增大后减小。冷凝温度越高,工质泵功率越大,发电机输出功率和系统热效率越小。当冷凝温度为65℃时,系统APR最大。受透平出口蒸汽干度的限制,所研究工况下,系统发电机最大输出功率为7 496 kW,系统最大热效率和APR分别为14.16%和5 kW·m~(-2)。研究结果可为撬装化、集成化海上油气平台余热发电系统研制提供理论参考。

Mechanical Analysis on Rankine Cycle for Waste Heat in Offshore Platform

A large amount of waste heat is produced in offshore platform.A simulation model of Rankine cycle for waste heat was established to carry out the electrothermal mechanics and economy analysis of platform waste heat power.The power of working fluid pump,power output,thermal efficiency,heat transfer area and power output for unit heat exchange area were selected to be the optimization objective.The regular of temperature difference between evaporator inlet and outlet on different condensing temperature were studied,The results show that power of working fluid pump,power output and APR increase first then decrease as temperature difference between evaporator inlet and outlet increase.The higher condensing temperature is,the larger power of working fluid pump is,however,the less power output and thermal efficiency are.When the condensing temperature is 65 ℃,APR arrives its maximum.As the restrictions of steam dryness of turbine outlet,the maximum power output is 7 496 kW,the maximum thermal efficiency and APR is 14.16％ and 5 kW·m-2 respectively.The conclusions can provide theory reference for integrated and shelled development of Rankine cycle for waste heat in offshore platform.