Dynamic Selection And Application Conditions Of Distributed Heating System

In the distributed heating system,the power plant,instead of the traditional heating system,can improve the stability and energy saving of the system.Therefore,it is a great significance for the application and popularization of distributed heating system that the correct selection of power plant and its applicable conditions research.First,this paper analyzes the working principle of the traditional heating system and the distributed heating system,pointing out the advantages of the distributed heating system.Combined with the structure and working principle of each power pump,it points out the application conditions of circulating water pump and jet pump in distributed heating system.Secondly,it is established the physical model of distributed heating system and introduced the concept of Zero pressure difference to segment the distributed heating system,that is,the heat source to the first station of the heat transfer station,the position of the heat transfer first station and the Zero pressure difference position,the Zero pressure difference position and the most unfavorable heat user section.It is derived a formula for calculating the power of each section to compare with the energy consumption of the traditional heating system,presenting the energy saving advantage of the sectional heating system.During the system transformation of the actual heating engineering,it is changed the length of the control parameter pipe network,the distribution of user heat load and the specific friction resistance of the system pipe network and calculated the number of circulating pumps under the control parameters,the first grade pump head,power and the energy saving rate of the system.It is found that three kinds of control variables change the position of Zero pressure difference in the system,the control of the location of Zero pressure difference is the main influencing factor for the design of hydraulic condition.It is found that three kinds of control variables change the position of zero pressure difference in the system,the control of the location of zero pressure difference is the main influencing factor for the design of hydraulic condition.Thirdly,it is not only expounded the type,structure and working principle of the jet pump but also given the distribution trend of axial pressure and velocity in the center of ejector pump,explaining the running process of the jet pump and the hydraulic working condition of the internal fluid.A double disc linear control valve is introduced,It is found that the working fluid temperature is the most important factor affecting the efficiency of the jet pump and the flow rate of the working fluid and the loss of the user pressure head will not affect the efficiency of the jet pump.Based on MATLAB software programming,we can verify the numerical results of temperature field,pressure field and velocity field though CFD method.In order to study the effect of ejector operation,this paper changes the heat user loss of head size and working fluid temperature,finding that working fluid temperature has great effect on the jet pump operation,working fluid flow and user head loss will not affect the basic operation quality of jet pump.It is studied the application of jet pump in heating engineering and discussed the influence of the installation position of water jet pump on the characteristics of the system pipe network.It is studied the influence of the location of the water jet pump on the pipe network characteristics and the water jet pump will improve the pressure head of the pipe network and change the Zero pressure differential location of the system.It is discussed that the application value of water jet pump in high and low buildings,which points out the applicable conditions and application conditions of the water jet pump in the water supply pipe and the backwater pipe network.Finally,it is the analyzed heating methods of traditional high-rise buildings,high-rise buildings and tier buildings and found that they do not make use of backwater static pressure to cause energy waste.It is studied that the heating mode of the traditional high-rise small and high level residential district,which gives a design scheme.This paper analyzes the actual heating project and calculates the annual conversion cost of the pressurized water pump and water jet pump installed.It is found that the water jet pump is more suitable for the high-rise heating building.The annual conversion cost of low-temperature radiation and the heating mode of the radiator end is calculated separately.It is found that the low temperature radiant heating mode has lower cost and more energy saving advantages.