High back-pressure (HBP) retrofit is a satisfactory approach to enhance the heat-supply capacity of combined heat and power (CHP) units via waste heat recovery. In this study, focusing on economic operation, the problems regarding the plant-level dispatch of a cascade heating CHP plant with the HBP technology are addressed. In consideration of the operation region (OR) and load balancing constraints, the optimal dispatch strategies are proposed. It is found that the optimal heat load sharing ratio of the HBP unit can be predicted via the real-time temperatures of supply water, return water, preheat water, and heat load. For the extraction-condensing (EC) units, the uneven distribution of heat-power loads is a preferable coal-saving option. A case study is then performed to show the favorable outcomes quantitatively. Results show that the heat load sharing ratio of the HBP unit would be increased by about 8.01% overall. Moreover, the optimal heat-power loads of the EC units present a clear law. From the plant-level perspective, the average coal saving ratio is 0.76%. Besides, the reduction of standard coal consumption of the case plant is about 607,829 tons during the heating season, which means that 1.59 million tons of CO₂ would be accordingly reduced.

高背压 (HBP) 改造是通过废热回收提高热电联产 (CHP) 机组供热能力的令人满意的方法。本研究以经济运行为重点，解决了采用 HBP 技术的梯级供热 CHP 电厂的厂级调度问题。考虑操作区域（OR）和负载均衡约束，提出了最优调度策略。发现HBP机组的最佳热负荷分担比可以通过供水、回水、预热水和热负荷的实时温度来预测。对于抽-凝（EC）机组，热电负荷分布不均是一种较好的节煤方案。然后进行案例研究以定量显示有利的结果。结果表明，HBP机组的热负荷分担率总体提高了约8.01%。此外，EC机组的最佳热电负荷呈现出明确的规律。从厂级看，平均节煤率为0.76%。此外，案例厂采暖季减少标准煤消耗量约607829吨，即减少二氧化碳排放159万吨。₂会相应减少。