Experiment Investigation And Application Analysis On Insulation And Exhaust Pressure Of Breathing Well Covers Based On Hot Box Method

With the rapid development of China's economy,the country's allocation of water resources more and more frequent.Transporting water from a richer area to a designated area requires a longer water supply,and at every interval,the exhaust pipe is required to remove gas from the pipe.In some cold and cold areas,if the exhaust valve in the water supply pipe directly to the outdoor air,the exhaust valve will be frozen and could not be normal exhaust due to low outdoor temperature in winter.An air valve is needed between the exhaust valve and the outdoor atmosphere.The exhaust valve discharges the gas in the water supply pipe into the air valve well,which then discharges the gas through the manhole cover.Manhole cover in the air valve shaft exhaust process plays a huge role,on the one hand the air valve well gas discharge,on the other hand to ensure that the air valve shaft and the outdoor heat transfer volume should not be too large to prevent air valve well temperature is too low to exhaust valve of the water supply pipe to freeze.In the research the method and the exhaust pressure test hot box for the literature data,a lot of research work,based on the thermal insulation performance and the exhaust breathing covers performance testing principle and experimental scheme,introduces the design and construction of experimental platform,and introduces the experimental equipment and related equipment.Three kinds of well cover,the best thermal insulation for the No.3 manhole cover,its heat transfer is 160 W,the worst for the No.1 manhole cover,the heat transfer is 160 W.Under the condition of enhanced frosting,the exhaust pressure of No.2 well cover is 200 Pa,which is twice as good as that without frosting.When the cover of No.3 covers is frosted,the exhaust pressure is 800 Pa,and the exhaust pressure is increased by 60%.The thermal insulation performance of the insulation cover with different structure is studied,the exhaust performance of the manhole cover is measured,and the exhaust pressure of the insulation cover is measured.On the basis of experiment test,first queries the meteorological parameters in Fushun City,the general year and extremely cold years using different types of well within the lowest temperature was calculated.Analyzed the well chamber in different water temperature using 3 different heat preservationcovers the well chamber winter minimum temperature,and obtained the well chamber temperature is not lower than the Frost temperature,the number of heat preservation covers need to be closed.Through the research of this subject,the insulation performance and exhaust performance of 3 kinds of insulation breathing manhole covers are obtained.The corresponding improvement measures are put forward according to the safety protection cover and the cover.On the basis of the experimental study,the indoor temperature of the air valve well is analyzed and simulated,and the results show that the temperature of the well chamber is not lower than the frosting temperature,which needs to be closed.This paper was through theoretical analysis,experimental research and engineering practice of combining research methods.The first insulation performance and the exhaust performance of three types of insulation breathing manhole cover was studied by ANSYS analysis software on the basis of experimental results,the simulation study of thermal analysis in air breathing valve covers well application.The research results of this paper have some guiding significance for the improvement of the performance of the insulation and the application in the air valve well.