以热定电模式下热电联产机组电功率灵活调节能力分析

Analysis on Electric Power Flexible Regulation Capacity for Combined Heat and Power Units in Heat-led Mode

"以热定电"模式下热电联产(CHP)机组的电功率输出受机组供热负荷制约,对于以采暖负荷为主的CHP机组,区域集中供热系统的供热时滞性和采暖用户的热惯性使其供热负荷具有灵活性,其电功率输出仍具有一定的灵活调节能力。分析了供热管网热损失、供热时滞性,以及采暖用户热惯性对CHP机组供热负荷的影响,并利用生产模拟方法生成供水温度、抽汽量与供热负荷样本数据,通过拟合方法将抽汽量表达为供水温度与供热负荷的函数,用以描述汽水换热器的热传递过程。在此基础上,构建了一种CHP机组电功率灵活调节能力评估模型。算例分析证明,所述模型可用于分析CHP机组利用供热时滞性和热惯性作用所能提供的电功率调节范围,以及相应的成本指标。

The power output of combined heat and power (CHP)units in the "heat-led"mode is usually constrained by the heating load.For the heating load based CHP units,the time delay of district heating system and the thermal inertia of users make the heating load flexible,which makes the electric power still have the flexible regulation capacity.The influence of heat loss of heating pipeline network,the time delay of hot water transmission and the thermal inertia of the heating users on units heating load is analyzed.And the production simulation method is applied to generate the sample data of supply water temperature,the mass flow rate of extraction steam and heating load.Then the mass flow rate of extraction steam is expressed as a function of supply water temperature and heating load through fitting method,which is used to describe the heat transfer process in the gas-liquid exchanger.On this basis,an evaluation model of electric power flexible regulation capacity of CHP units is constructed.The simulation results show that the proposed model can be used to analyze electric output adjustment range of CHP units based on the time delay of hot water transmission and thermal inertia,as well as the corresponding cost index.