| Traditional air-conditioning systems have high energy consumption,poor indoor air quality,and a strong sense of blowing and noise.As an energy-saving,comfortable and healthy green air-conditioning system,radiant air-conditioning system has the advantages of good economy,thermal comfort,and high indoor air quality compared with traditional airconditioning systems.However,it is easy to condense,low cooling capacity and high initial investment.The three main issues that limit the development of radiant air conditioning systems.Among them,condensation is an important problem that limits its cooling capacity and engineering applications.Therefore,how to effectively solve the condensation problem of radiant air-conditioning system,improve its cooling capacity,and expand its application range is particularly important.Aiming at the problem of easy condensation in radiant air conditioning systems,this paper proposes a radiant air conditioning terminal anti-condensation system based on selective transmission of radiant film,which wraps the radiant panel with a radiant film with high infrared transmittance in the wavelength of 8～12μm.The radiant panel is completely isolated from the indoor air,and the film allows heat radiation to pass,but does not allow air and humidity to pass.Analyze and study the condensation on the radiant cooling surface of the radiant air conditioning terminal anti-condensation system that selectively penetrates the radiant film radiant air conditioner under different temperature and humidity environments and different water supply temperatures through experimental research.The results show that: the same water supply temperature and indoor environment Conventional radiant panels are more prone to condensation than radiant panels that selectively pass through the radiant film,and the relative humidity in the gas interlayer is 20%.Even if the water supply temperature is lowered,the dew point temperature in the gas interlayer is very low,and no condensation occurs on the surface of the radiant panel.In the same indoor environment,when the water supply temperature of the conventional radiant panel is 16℃,and the relative humidity of the indoor air is 50%,condensation will appear on the cooling surface of the radiant panel.When the water supply temperature of the radiant panel is 12 ℃,when the relative humidity of indoor air is 65%,condensation will appear.A simulated room was built to study the cooling and heating heat transfer characteristics of conventional radiant panels and selective radiant film radiant panels.The results showed that:increase the flow rate of cold water supply,that is,the water flow rate,conventional radiant panels and selective radiant film radiant panels The cooling capacity is increased first and then decreased.When the water supply flow reaches 0.227m3/h,the cooling capacity reaches the maximum.Under the same water supply flow,the air temperature of the selective radiant film radiant panel is 0.94 higher than that of the conventional radiant panel on average.℃,the wall temperature is 1.13 higher.With the increase of the water flow rate,the surface temperature ℃of the radiator panels of the two radiator devices will decrease and the change trend is the same;Reduce the temperature of cold water supply,improve the heat exchange performance of conventional radiant panels and selective radiant film radiant panels,and increase the cooling capacity.At the same water supply temperature,the air temperature that selectively penetrates the radiant film radiant panel is 0.93℃ higher than that of the conventional radiant panel,and the wall temperature is 1.02℃ higher.With the increase of outdoor environment temperature,indoor wall temperature and air temperature will increase accordingly.For every 1℃ increase in outdoor environment temperature,the air temperature of conventional radiant panels will increase by 0.83℃,and the wall temperature will increase by 0.88℃.The air temperature of the radiant film radiant panel increases by 0.85℃,and the wall temperature increases by0.91℃.At the same ambient temperature,the surface temperature of the selective radiant film radiant panel is 1.49 ℃lower than that of the conventional radiant panel.After the film is installed,the surface temperature of the radiant panel selectively permeates the radiant film for every 5 increase in ambient temperature.With an increase of 1.08°C,the surface temperature ℃of the conventional radiant panel increases by 1.51°C.The infrared spectroscopy experiment of the radiation film is carried out by Fourier infrared spectrometer: the 50μm thick radiation film selected in this experiment has a corresponding transmittance of 82.9% in the long wavelength band of 8-12μm. |
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