在“双碳”目标下，热电联产机组为实现低碳灵活运行进行热电解耦改造。以某350 MW热电联产电厂的热电解耦改造为例，建立加装电锅炉机组模型、抽汽供热机组模型、低压缸切除机组模型，研究了改造前后机组的碳排放特性以及不同解耦方式组合后机组边界，选取了其中两种方案，分别进行以碳排放最低的单目标热电负荷优化和考虑碳排放以及收益的多目标热电负荷优化。研究表明：低压缸切除机组的供热、供电碳排放强度相比抽汽供热机组更低；抽汽供热机组耦合低压缸切除机组与加装电锅炉机组在热负荷为400~800 MW时有相近的电热特性；依据外界热负荷需求选择不同解耦方式有利于机组灵活运行；双机运行时1台机组承担主要热电负荷有助于减少机组碳排放；在文中背景下调峰收益高、碳交易收益低；机组碳排放量与机组总收益呈正比；热电解耦使机组收益随碳排放量增加更稳定。
Under the "dual carbon" goal, cogeneration units undergo thermoelectric decoupling transformation to achieve lowcarbon and flexible operation. Taking the thermoelectric decoupling transformation of a 350 MW cogeneration power plant as an example, a model of an additional electric boiler unit, a model of an extraction and heating unit and a model of a lowpressure cylinder cutting unit are established. The carbon emission changes and corresponding carbon emission characteristics of the unit before and after the transformation and the boundary of the unit after combining different decoupling methods are calculated, and two of these schemes are selected to conduct single objective thermoelectric load optimization with the lowest carbon emissions and multiobjective thermoelectric load optimization considering carbon emissions and benefits, respectively. Research shows that the carbon emission intensity of the heating and power supply of the lowpressure cylinder cutting unit is lower than that of the steam extraction heating unit; the coupling of the lowpressure cylinder cutting unit and the steam extraction heating unit has similar electric heating characteristics with installed electric boiler unit when the heat load is between 400 MW and 800 MW; selecting different decoupling methods based on external heat load demand is beneficial for the flexible operation of the unit; when two units are running, one unit bears the main thermal and electrical loads, which helps to reduce the carbon emissions of the unit; under the background of this paper, the peak shaving benefit is high, carbon trading benefit is low; unit carbon emissions are directly proportional to the total unit revenue; thermoelectric decoupling makes the unit′s revenue more stable with carbon emissions.