300 MW机组供热蒸汽余压发电汽轮机选型研究

Research on Selection of Steam Turbine for Power Generation Using Residual Pressure of Heating Steam in 300 MW Units

为解决热电联产机组供热蒸汽压力过高而造成高品质蒸汽能量浪费的问题,提出了增设功–热汽轮机以回收利用供热蒸汽中的高品质能量。针对某300 MW机组供热蒸汽余压发电改造方案,结合采暖期机组热网系统实际运行参数,在分析选取功-热汽轮机的进汽参数、排汽参数及进汽量时需考虑的主要影响因素基础上,通过核算确定了功-热汽轮机的主要技术参数(额定功率6 MW、进汽压力0.36 MPa、进汽温度240℃、排汽压力0.070 MPa、排汽温度105℃、相对内效率80.4%),指出选型过程中要综合考虑机组采暖期内供热蒸汽参数、高压厂用电负荷、采暖抽汽量、热网水流量等因素。结论可为同类型机组改造时汽轮机选型提供参考。

In order to solve the problem of high-quality steam energy waste caused by high heating steam pressure of cogeneration units, a method that adds power-heat steam turbine to recycle the high-quality energy in heating steam is proposed. As for the retrofit scheme of a 300 MW unit for power generation using residual pressure of heating steam, combined with the actual operation parameters of the heating network system of the unit in the heating period, the main technical parameters of the power-heat steam turbine were determined through calculation(the rated power is 6 MW, the inlet steam pressure is 0.36 MPa, the inlet steam temperature is 240 ℃, the exhaust steam pressure is 0.070 MPa, the exhaust steam temperature is 105 ℃, and the relative internal efficiency is 80.4%), which is based on the analysis of the main influencing factors to be considered when selecting the steam inlet parameters, exhaust parameters and steam inflow of the power-heat turbine. It was proposed that factors such as the parameters of heating steam, the load of high-pressure auxiliary power, the amount of heating steam extraction, heat supply network water flow should be considered comprehensively in the selection process.The conclusion can provide a reference for the selection of steam turbine in the transformation of the same type of unit.