热负荷分配比例对抽凝-背压供热机组能耗影响

抽凝-背压供热模式是实现能量梯级利用、降低火力发电煤耗的有效途径，研究不同室外温度下供热凝汽器与尖峰加热器热负荷分配比例对机组能耗的影响，确定最佳热负荷分配比例，是抽凝-背压供热机组节能降耗的核心问题之一。本文利用热网变工况模型及Ebsilon软件仿真，以某310MW抽凝-背压供热机组为研究对象，分析了供热期不同温度下供热凝汽器与尖峰加热器热负荷分配比例不同时机组的发电功率及煤耗。结果表明：对于抽凝-背压热电联产机组，并非供热凝汽器热负荷比例越高而发电功率越高，供热期不同阶段，机组发电功率随供热凝汽器热负荷变化呈现不同规律；相同室外温度下，供热凝汽器与尖峰加热器热负荷分配比例对机组能耗影响很大，凝汽器热负荷比例不同时，其极差最小值和最大值分别为2.02g/（kW·h）和5.50g/（kW·h）。

Impacts of heat load distribution ratio on energy consumption of extraction steam-high back pressure heating cogeneration unit

Using extraction steam-high back pressure heating mode is an effective way to achieve energy cascade utilization and reduce the coal consumption rate in cogeneration units. In a cogeneration power plant,a key issue for energy saving is to determine the optimal value of heat load distribution ratio between heating condenser and peak load heater,based on the power plant energy consumption variation resulting from the heat load distribution ratio between heating condenser and peak load heater. The output power was simulated by using Ebsilon platform,and coal consumption were calculated under conditions with different heat load distribution ratios. Results showed that heat load distribution ratio greatly affects cogeneration unit energy consumption. The variation of coal rate range is from 2.02g/(kW·h) to 5.50g/(kW·h),due to the change of heat load distribution ratio between heating condenser and peak load heater. The relations between the output power and heating condenser heat load distribution ratio varies with heating stages.