Research On Heating Technology Of High District Return Water Driving Low District

In the traditional heating system,the common way of heating is to use the regulating valve to regulate and eliminate the excess pressure head,but this way will cause problems such as hydraulic imbalance,increased power consumption and energy waste.In view of the above problems,it is proposed that the distributed heating system is widely used in today’s society.The form of "baton" is adopted in the distributed heating system to realize the transmission of heat medium,which greatly improves the utilization rate of energy and the stability of the system.However,with the improvement of people’s demand for heating,various kinds of multi-functional buildings have been built,and the building height is also increasing,The pressure of the heat dissipation equipment at the bottom of the building can not meet the pressure of the system.In order to further study the application of distributed heating system in high-rise buildings,this paper introduces the technology research of auxiliary heating with power device to meet the heating demand of heat users.In the group heating system of high-rise buildings,in order to meet the pressure demand of the most unfavorable loop,the pressure pump is usually set at the entrance of the heating system to pressurize according to the most unfavorable loop.There are still some problems,such as: the pressure of radiator and the impact of energy consumption waste,the original heating system can not meet the requirements of the existing heating scale.In order to solve this problem,this paper puts forward the research on the technology of using jet pump to supply heat in the high area return water and the low area.Secondly,introduce the application of jet pump in heating system,understand the domestic and foreign scholars’ research on jet pump,as well as the type,use and working principle of jet pump,through the analysis of its working principle,get the change chart of jet pump pressure and speed.According to the three laws of conservation of mass,momentum and energy in hydrodynamics,the relationship and calculation formula of the optimal section ratio,pressure ratio and injection ratio of the jet pump are studied,and the calculation process of the structural dimension of the jet pump is summarized.Finally,the structural dimension of the jet pump that can meet the requirements of the building is obtained according to the actual case.Thirdly,the three-dimensional modeling function of ICEM CFD software is used to establish the water jet pump model.The CFD method is used to simulate the model,set the boundary conditions,and obtain the temperature field,pressure field and velocity field numerical simulation verification.By changing the parameters of different nozzle distance,area ratio and mixing pipe length,the influence trend of different parameters on the efficiency of jet pump is analyzed.At the same time,changing the parameters of jet pump will affect the supply and return water pressure in high and low areas,that is,the demand of heat users for heat supply.So choosing a more suitable jet pump has a great impact on the performance of water jet pump in heating engineering.Finally,according to the analysis of the heating mode of high-rise buildings,it is found that after the transformation,there is no waste problem caused by the static pressure of return water in high-rise areas.It is used in practical heating engineering to analyze the problems,and to a certain extent,it also brings the effect of saving electricity and heat.In the process of heating,a large number of harmful substances,such as nitrogen oxides,sulfides,soot and so on,will be released due to the combustion of coal and natural gas.When jet pump is used to assist low-pressure fluid with highpressure fluid,it not only eliminates the phenomenon of low temperature or overheating in the hot user’s room,but also improves the energy utilization rate and reduces the system maintenance rate.