Research On Intermittent Radiant Heating Of Phase-change Energy Storage Floor In Residential Buildings In Villages And Towns

In consideration of economic and living habits in northern villages and towns in China,many residential buildings still use coal as a heating method,which is not comfortable and pollutes the environment.In recent years,the northern region has vigorously promoted the development of clean heating in villages and towns,and explored an effective way to convert coal to clean energy for heating.China's power supply is adequate,but the problem of uneven power load between day and night is more serious.To alleviate this problem,policies such as peak-valley electricity price differentials and state subsidy electricity prices have been implemented.For this reason,based on the current status of energy and village heating in China,this paper focuses on the phase change material storage(electricity)heating floor radiant heating system,proposes a radiant heating method combining phase change material with floor by storing off-peak electricity and provides the new solutions which can improve the quality of clean heating in villages,reduce heating costs and cut peak fill valley in electricity.Firstly,the paper selects the research object,establises the floor radiation heat transfer model,and carries out the numerical analysis.A typical room in a northern village and town was selected as the research object,and a mathematical model of rooms such as exterior walls,roofs,and phase change energy storage floors was established.Matlab was used to program and calculate the thermal performance of the room heated by electric heating and phase change energy storage floors simulation study.Subsequently,the factors that affect the thermal performance of the room with phase change energy storage floor heating are analyzed.The paper uses PMV,PPD,operating costs and other indicators to evaluate the advantages and disadvantages of the three operating modes.The following conclusions are drawn:(1)The relative heating power ratio has the greatest impact on the performance of the phase-change energy storage floor.Different intermittent operating times have different relative heating power ratios.(2)The better thickness of the phase change material layer is related to the intermittent operation time.With the extension of the intermittent operation time,the thickness of the phase change material layer that needs to be stable at room temperaturewill also increase.(3)As the thermal conductivity of the phase change material increases,the indoor average temperature also increases,but the indoor temperature fluctuations increase and the floor energy storage ratio decreases.(4)As the phase transition temperature increases,the average surface temperature of the floor and the indoor average temperature also increase,and the floor energy storage ratio increases first and then decreases.(5)The latent heat of the phase change increases,the room temperature becomes lower,and the floor energy storage ratio increases,but as the latent heat of the phase change continues to increase,these changes slow down.(6)The Bier number(Bi)of the floor decoration layer will affect the fluctuation of the floor surface temperature and the indoor temperature.The higher the Bi,the greater the indoor temperature fluctuation.In addition to Bi,the choice of floor covering needs to be comprehensively considered based on actual working conditions.