Study On Energy Saving Characteristics Of Capillary Radiation Air Conditioning System And Phase Change Material

As the country's requirements for energy conservation and consumption reduction have increased,building energy conservation has received more attention as an important part of social energy consumption.Capillary radiant air conditioning and phase change materials are two new types of building energy-saving technologies.The combination of the two technologies is important for further reducing building energy consumption.The former cools the room through the capillary radiant top plate,and uses the high temperature cold source to realize efficient use of energy.The latter uses the phase change latent heat of materials to store cooling capacity,reduce the indoor maximum load,and improve indoor Comfort level.In this paper,the energy-saving effect and influencing factors of phase change material(PCM)in capillary radiant air-conditioned rooms are studied,and reasonable suggestions for engineering applications are put forward.In this paper,the heat transfer model of the phase change wall is established by using the enthalpy method,and the influencing factors of the phase change wall are mainly the application conditions of the wall,the position and thickness of the phase change layer,etc.Secondly,using EnergyPlus to build a capillary radiant air conditioning system simulation model and an office model incorporating phase change materials,By changing the installation thickness of the phase change material(5~30mm)and the laying area to the surface ratio of the wall(10%~100%),the energy consumption of the air conditioning system in Wuhan is simulated.The system energy saving rate and the phase change material investment recovery period of each working condition are calculated.In this study,the organic phase change material BioPCM was used,and the latent heat of phase change was 230kJ/kg.The results show that the combination of capillary radiant air conditioner and phase change material can reduce the peak value of cold load(such as the peak of cold load of4.08%on July 31),and has a certain"shift peak filling"effect.The energy saving rate of the air conditioning system increases with the increase of the thickness and area ratio of the phase change material,and the growth rate is gradually reduced.When the phase change material is installed with a thickness of 30 mm and the laid area is 100%,the system energy saving rate reaches a maximum value of 20.51%.The PCM investment payback period tends to decrease first and then increase with the increase of laying area and thickness.When the ratio of different laying areas is occupied,the minimum value of PCM investment recovery period appears in the thickness of 15mm.The optimum installation thickness of the phase change material in the capillary radiant air-conditioned room is 15mm,the optimal laying area is 40%,the air conditioning system energy saving rate is 9.02%,and the investment recovery period of PCM is 15.05 years.If the PCM volume is constant,the installation thickness and area ratio are the best combination,the system energy saving rate is the largest,and the investment recovery period of PCM is the shortest.In practical engineering applications,the optimal installation thickness and area ratio combination of PCM can be selected according to the following recommendations:V(PCM volume)?0.26m~3,thickness is 10mm;0.26m~3<V?0.467m~3,thickness is 15mm;0.467m~3<V?0.623m~3,thickness is 20mm;0.623m~3<V,thickness is 25mm.The optimum laying area of PCM should not exceed 60%.