微燃机冷热电三联供系统建模及热力学分析

某200 k W微燃机冷热电三联供系统按季节负荷特点分为热电联供和冷电联供2种模式,基于Ebsilon软件对该系统构建模型并进行仿真模拟及性能分析,分别计算出不同工况下冷热电三联供系统的一次能源利用率和效率。结果表明:冷电联供时,环境温度从24℃变化到38℃,系统一次能源利用率为65.2%~68%;热电联供时,环境温度从-10℃变化到24℃,系统一次能源利用率为66.4%~74.2%。系统冷电联供(取环境温度为32℃)运行时,效率为31.1%,损失之和为451.92 kW,当微燃机负荷率在30%~100%变化,系统一次能源利用率为60.3%~66.9%;系统热电联供(取环境温度为0℃)运行时,效率为38.5%,损失之和为408.4 kW,当微燃机负荷率在30%~100%变化,系统一次能源利用率为54.4%~68.5%。通过搭建的微燃机三联供系统模型对实际运行数据进行分析,结果认为:实际运行工况主要存在冷负荷较小的问题,通过蓄冷罐蓄存多余冷量,系统的一次能源利用率可提高13.8%。

Modeling and Thermodynamic Analysis of the CCHP System Based on Micro Gas Turbine

According to the seasonal load characteristics, the CCHP(combined cooling heating and power)system based on 200 kW micro gas turbine comprises two modes, HP(heating and power) and CP(cooling and power). Ebsilon is used for system modeling, simulation and performance analysis to calculate the primary energy ratio and exergy efficiency under different conditions. The results show that in cooling and power supply mode when the ambient temperature changes from 24 ℃ to 38 ℃, the primary energy utilization ratio of the system varies from 65.2% to 68%;in heating and power supply mode when the ambient temperature changes from-10 ℃ to 24 ℃, the primary energy utilization ratio of the system varies from 66.4% to 74.2%;in the cooling and power supply mode with the ambient temperature of 32 ℃, the exergy efficiency is 31.1%,and the sum of exergy loss is 451.92 kW, and when the load rate of micro gas turbine changes in the range of30%~100%, the primary energy utilization ratio of the system is 60.3%~66.9%;when the system operates in the heating and power supply mode with the ambient temperature of 0 ℃, the exergy efficiency is 38.5%, and the sum of exergy loss is 408.4 kW, and when the load rate of micro gas turbine changes in the range of 30%~100%, the primary energy utilization ratio of the system is 54.4%~68.5%. By analysis of actual operation data based on the model of micro gas turbine triple supply system, it is found that the cooling load is relatively small in the actual operating condition, and by storing the excess cooling energy in the storage tank, the primary energy ratio of the system can be increased by 13.8%.