Research On Distributed Conversion Pumping System-Mixed Water System In Second Class Net

The growing energy crisis and the aggravating environmental pollution in China call for an increasing recognition on centralized heating system, since a chronic and serious problem of excessive energy consumption has plagued the engineers in the centralized heating system.Which may also accelerates the evolution for the centralized heating manner. In recent years,a novel heating manner-distributed conversion pumping system (kinetic dispersion system) is promoted by domestic and overseas scholars, and it has been researched and applied widely.Considering the ubiquitous heat maladjustment of the second class net in heating system, this paper converts the traditional heating manner into a distributed conversion pumping-consumer heat inlet mixed water system based on the philosophy of both two systems. It expects to address the condition effectively,that is the heat maladjustment of the second class net as well as the high energy consumption in the heating system.The paper illustrates the basic types, the characteristic and the design method as well as the energy saving effect of the system.. In order to meet the flow and head of the heat user, it adjusts the mixing-pump through a constant pressure difference. Simultaneously, it runs frequency control through the second class net pressure circulating pump so as to changer the ratio of the mixing water and then automatically adjust the water temperature. All the pumps in the system experience a frequency control, it can realize unified manage.Firstly, the second class net heating system of a district is studied using the SimHydraulics toolbox and Simscape programming language in the Matlab Simulink module library. With the theory guidance of equivalent length method it defines the physical simulating model of water pump, balance valve and radiator. Then it run the simulation for the district using both traditional heating system and the new system promoted in this paper,the hydraulic regime characteristic comparison of the two system show that the latter demonstrate much more stable hydraulic and can save more energy. Finally, a dynamic simulation of using balance valve to adjust the hydraulic balance is studied. It drafts a reasonable and effective hydraulic balance regulation scheme, which can decreased the workload in engineering site,dramatically,and improve the work efficiency.