区域供暖换热站温差影响因素及模拟分析

Simulation analysis and influence factors of temperature differences in substations of a district heating system

基于热力学基本定律创建整体供暖系统动态模型,并用于换热温差的分析和研究。文中考虑了室外温度、室内温度、实供面积、一次网循环流量、二次网循环流量、换热器综合传热系数及散热器散热面积对换热温差的影响,并通过模拟得出影响二次供水与一次回水温差(T_(s2r1))和一次回水与二次回水温差(T_(r1r2))的最大因素。多重因素分析、动态控制仿真及供暖系统实测数据均显示T_(s2r1)和T_(r1r2)之比约为2~3:1,此数据可作为系统运行人员参考。

An overall dynamic model of a district heating system was developed according to basic thermodynamic law and was utilized for analyzing and studying temperature differences of substations. The influence factors such as outdoor air temperature, indoor air temperature, actual heated floor area, flow rate in the primary system, flow rate in the secondary system,comprehensive heat transfer coefficient of heat exchanger and emission area of radiator were considered, and the maximal factors influenced temperature differences were found between supply water temperature in the secondary system and return water temperature in the primary system（Ts2r1）, and between return water temperature in the primary system and return water temperature in the secondary system（Tr1r2）. In terms of multi-factor analysis, simulation of system control and measured operational data of adistrict heating system, it can be seen that the ratio between Ts2r1 and Tr1r2is 23：1 approximately, and it could be used as reference for system operators.