Numerical Simulation And Experimental Research On The Thermal And Humid Environment Of A Site Museum In The Yellow River Basin

As the product of ancient human social activities,site museums have certain historical value,artistic value,and scientific research value.Preventing the destruction of soil ruins and prolonging the life of soil sites are the hot and difficult points of scientific research in recent years.Building a museum based on the original site of an earthen heritage site can better protect the earthen heritage site.The forms of it can be divided into closed and open.This paper proposes that air condition system should be introduced to control the temperature and humidity while protecting the earthen ruins.Numerical simulation was used to study the air distribution of the three layout schemes,and a simulation experimental platform was built to study the heat and humidity exchange between air and soil.The main research contents include:(1)Study the appropriate environmental parameters of the soil ruins protection area,make statistics of the environmental parameters of the current soil ruins museum by literature survey.Study the causes of soil ruins surface dryness and cracking,mold and other diseases in the indoor museum,and the environmental parameters suitable for the preservation of the soil ruins.The climatic conditions and geographical location of the earthen sites are studied,and the factors that may affect the earthen sites protection areas are analyzed.In this paper,the air temperature is 15±1℃,the relative humidity of 85 ± 5% design parameters of the protection zone.According to the specification of HVAC design,load calculation of the earth heritage protection area is carried out.(2)To meet the requirements of uniform temperature and humidity distribution and low wind speed on the surface of the soil site.The numerical models of three layout schemes were designed and established.The influence of the position of outlet and the angle of supply air on the uniformity of temperature and humidity distribution was studied by CFD software.The three arrangement schemes are of offside layout,same side layout and annular layout.The simulation results show that when the outlet is located at the bottom of the side wall,the distribution uniformity of the air distribution is greater and the wind speed is lower,followed by the annular layout.When the outlet is located at the top of the side wall,the gradient of temperature and humidity on the soil surface decreases,but the average temperature value increases,the average humidity value decreases,and the uniformity coefficient of temperature and humidity distribution increases.The influence of angle of inlet on air distribution is studied: the offside layout and annular layout have the lowest average temperature and maximum relative humidity,while the same side layout has the lower average wind speed and more uniform distribution of temperature and humidity.Therefore,for the soil heritage protection area studied in this project,the arrangement scheme of sending air upward at a small angle on the same side can obtain a better air distribution environment.(3)In order to study the heat and humidity exchange between air and soil in the soil conservation area,a simulated experimental wind tunnel was built.The effects of surface air temperature and soil temperature difference and wind speed on soil temperature and moisture fields were studied.The results show that when the surface air temperature is lower than the soil temperature,the higher the wind speed is,the soil surface temperature is more and more close to the surface air temperature,and the limit distance of cold transport is longer.When the wind speed is low,the surface soil may be affected by the fluctuation of ambient temperature,and the soil moisture content may increase.When the wind speed of the soil surface is high,the moisture content of the soil surface is not easy to change due to the small fluctuation of the surface air.So,when the wind speed is low,the temperature difference between the air and the soil has little effect on evaporation.However,with the increase of wind speed,the evaporation of soil is affected by the surface air temperature.