典型区域供冷系统用户换热站工艺水力学分析
Hydraulic analysis of typical user substations of district cooling systems
摘要：
对典型区域供冷系统用户换热站工艺配置进行了分类,对每种工艺的设计与运行工况进行了水力学分析。结果表明:在小流量负荷率时,工艺3～6具有更小的最小资用压差,比工艺1、2有较大的节能优势;工艺6采用调节阀先后调节策略运行后,可以承受较大的管网压差及变化,调节精度高,有较大适用范围;在水泵扬程允许的条件下,工艺1可以取消静态平衡阀;工艺3、4比工艺1、2有较大的实际可调比,工艺4的阀门先后调节策略具有较好的调节精度;由于采用高可调比调节阀,工艺5、6可以克服管网压差变化对实际可调比变化的影响。本文提出的理论分析方法为换热站工艺选择与优化设计提供了理论依据,也可作为管网运行优化的理论基础。
Abstract：
The typical process configurations of the user substations of district cooling systems are classified, and the design and operating conditions of each process are studied with hydraulic analysis. The results show that the processes 3 to 6 have a smaller minimum allowable pressure difference between the supply and return pipes of the substation when the flow load rate is small, which have a greater energy-saving advantage than the processes 1 and 2. While the process 6 adopts one valve by one valve operation strategy, it can withstand a large pressure difference and variation of the pipe network, the regulating accuracy is high, and it has a wide range of application. Under the condition that the pump head allows, the static balance valve can be eliminated for the process 1. The processes 3 and 4 have a larger actual regulation ratio than that of the processes 1 and 2, and the valve regulation strategy of the process 4 has a better regulation accuracy. Due to the use of high regulation ratio control valves, the processes 5 and 6 can overcome the influence of the variation of pressure difference of the pipe network on the change of actual regulation ratio. The theoretical analysis method proposed in this paper provides a theoretical basis for the process selection and optimization design of the user substation, and can also be used as the theoretical basis for the operation optimization of the pipe network.
Keywords:district cooling; user substation; process; hydraulics; minimum allowable pressure difference; maximum pressure difference of pipe network; regulating accuracy