清洁能源发电并网，导致大量热电联产机组在非采暖季有时难以满足外部用热需求。回收机组的发电余热不仅能有效降低供热过程中的有用能损失，还能进一步提高机组的供热能力，充分挖掘热电联供机组的节能潜力。本文针对某电厂的两种供热改造方案进行了对比，基于EBSILON平台分模块建立各设备的热力学模型开展了仿真试验。改造方案1为2#机切缸抽汽改造+1#机高背压乏汽利用同时打孔抽汽改造，改造方案2在方案1的基础上汽机系统串联在高背压热网凝汽器A和热网首站的加热器之间，提高系统的能量梯级利用能力。在典型供热工况下，研究供热量分配对两台机组抽汽量和系统热耗率的影响。结果表明，采用增汽机后，系统总热耗量更小，系统能效更优。

The grid connection of clean energy power generation leads to a large number of cogeneration units, which are sometimes difficult to meet the external heat demand in non heating seasons. Recovering the waste heat of power generation of the unit can not only effectively reduce the loss of useful energy in the heating process, but also further improve the heating capacity of the unit and fully tap the energy-saving potential of cogeneration unit. This paper compares two heating transformation schemes of a power plant, establishes the thermodynamic model of each equipment in modules based on EBSILON platform, and carries out simulation tests. Retrofit scheme 1 is the retrofit of cylinder-cutting steam extraction for unit 2 and the use of high backpressure spent steam for unit 1 while perforating the steam extraction. Retrofit scheme 2 is based on scheme 1, where the steam engine system is connected in series between the condenser A of the high backpressure heat network and the heater of the first station of the heat network, to increase the system ability to utilize energy in a graded manner. Under typical heating conditions, the impact of heat supply distribution on the amount of steam extraction and system heat consumption rate of the two units is studied. The results show that the total heat consumption of the system is smaller and the energy efficiency of the system is better.