Research On Natural Seasonal Ice Storage Device In Northeast Severe Cold Regions

With the increasing energy consumption of building heating and air conditioning,the rising price of fossil fuel and serious environmental pollution,the voice of building energy conservation is increasingly urgent.Using natural energy is an effective way to realize building energy saving.Making full use of natural energy is an important way to reduce the dependence on conventional energy and realize building energy saving.Natural energy has the characteristics of low energy flow density,discontinuity and instability.It is necessary to combine energy storage means to achieve continuous and stable energy supply.It is of great significance to study cross season natural ice storage device to reduce building energy consumption.This paper designs a kind of cylinder type cross season natural ice storage device,puts forward the calculation method of the economic thickness of the cold insulation layer for the cold insulation problem of the device,and uses MATLAB software to calculate and analyze the economic thickness of the cylinder type cross season natural ice storage device in Harbin,Changchun,Shenyang and Beijing.The results show that the economic thickness of cold insulation increases with the increase of cold price and the diameter of ice storage device.When the diameter of the device is given to be 2M and kept until June,the best cold insulation thickness of Harbin,Changchun,Shenyang and Beijing is 11cm,10.6cm,11.2cm and 11.7cm respectively,and the cold loss is 1.089 GJ,1.0548 GJ,1.1253 GJ and 1.1675 GJ respectively.A quick method to determine the economic thickness of cold insulation in different areas is proposed.Through the reasonable simplification of the natural ice storage device across seasons,the mathematical model of the heat transfer process is established,and the model equation is discretized and solved.Through the differential integration of the heat transfer equation inside and on the surface of the device,the discrete equation of the heat transfer equation inside and on the surface of the phase change energy storage module is obtained.The boundary micro element is analyzed,and the discrete square of the heat transfer fluid energy equation is obtained Matlab software is used to calculate and solve the internal temperature field of phase change energy storage module.The ice storage depth of 10 days,30 days,60 days and 90 days in Shenyang area was obtained.It provides a theoretical basis for device optimization.In this paper,the model of ice making and ice storage of natural ice storage device across seasons is established by using FLUENT software.The boundary conditions of simulation and reasonable grid division are given.Through the use of MATLAB software to test the outdoor weather parameters for data fitting,using FLUENT software user-defined(UDF)to fit the weather parameters into the boundary conditions,more accurate simulation data.The influence of these three factors on the ice making process can be obtained by changing the inlet size,inlet wind speed and air passage size,and the influence of changing the air passage size on the ice storage process can be obtained.The results show that the error between the experimental and numerical simulation data is within a reasonable range,the root mean square error is 0.48k.Finally,the structure optimization and energy saving potential of the natural ice storage device are analyzed.Using the calculation method of static economic recovery period,it is obtained that when the recovery period is 5 years,the height of cross season natural ice storage device is 1.21m.Considering the loss of ice storage and use process,1.82×10~6KJ-1.77×10~6KJ of cooling capacity can be obtained every year.In terms of environmental protection benefits,the cross season natural ice storage device also has a good performance.For thermal power generation,1k W·h electricity needs to consume 0.4kg standard coal,and generate 0.272kg carbon dust,0.997kg carbon dioxide,0.03kg sulfur dioxide and other pollutants.Cross season natural ice storage device can use natural cold source to make ice,reduce electricity and ice,thus reduce pollution caused by thermal power generation.Combined with the typical annual hourly parameters(extremely high temperature)in the special software for thermal environment analysis of Chinese buildings,the optimal ice making radius of natural ice storage device across seasons in Harbin,Changchun and Beijing is given,and the device size in different areas is guided.