集中供热系统多热源调度优化模型

Scheduling optimization model for multi-source district heating system

多热源集中供热系统在运行成本、一次能耗和可靠性等方面相较于传统单热源系统取得很大的进步。针对多热源集中供热系统运行过程中热源负荷分配和调度的优化问题,建立了在满足系统供热量平衡和流量平衡的前提下,使系统热源的运行费用和污染物综合排放量最小化的优化模型,以确定不同室外温度时各热源的运行状态和所承担的热负荷。同时,针对此多目标模型求解的复杂性,对模型中的等式约束进行降维或松弛处理,并用NSGA-Ⅱ和TOPSIS求解。最后,以某热源为燃气热电厂(设计热负荷147 MW)、燃气锅炉房(设计热负荷80 MW)和第2类吸收式热泵系统(设计热负荷41.2 MW)的多热源集中供热系统为例,给出了热源优化调度方案和供热调节方式。采用该优化调度方案,实现了吸收式热泵系统的满负荷运行,从而优化了集中供热系统的运行费用和污染物综合排放量;而提出的供热调节方式实现了燃气热电厂部分流量运行,减少了运行费用,在严寒期,各热源通过流量分配实现了热负荷的分配。

Compared with ordinary single-source heating systems,multi-source district heating systems have many advantages such as low operating cost,low primary energy consumption and high reliability in heat supply.Against the optimization problem of heat source load distribution and scheduling in the operation process of multi-heat source central heating system,a scheduling optimization model for a multi-sources district heating system is developed to predict and determine the operation state and the thermal load of each source with good economic and environmental performance at different ambient temperatures.Both the operating cost and the integrated pollutant emissions have been taken as optimization goals and the heat demand requirements for the customers are also considered in the model.The dimensionality reduction or relaxation method for equality constraints is introduced to make the solution of the optimization model easy.Then,the multi-objective optimization model is solved by the NSGA-Ⅱmethod and the TOPSIS method.At last,the scheduling optimization model is applied in a case study of a multi-sources district heating system with three heat sources including a gas-fired thermal power plant(with design heat load of 147 MW),a gas-fired boiler(with design heat load of 80 MW)and a second-class absorption heat pump system(with design heat load of 41.2 MW),and the heat source optimization scheme and heating regulation method are given.In the optimal scheduling scheme,the absorption heat pump system is operated at the full load mode to optimize both the operating cost and integrated pollutant emissions of the district heating system.In the proposed regulation scheme,the gas-fired thermal power plant is operated under part-load conditions to reduce the operating cost.Additionally,the heat load distribution for all heat sources are done by the water flow distribution in the cold period.