Thermal Performance Test And Analysis Of A Tube Type Radiation And Convection Air-conditioning Device

The low-temperature radiation heating system has been widely adopted for its mature development, but the radiant cooling system remains in theory and experimental research because of condensation problems, thus is not widely used in practice. The object of this paper is new terminal equipment-wall panel radiation convection heat exchanger which relies on radiation and natural convective heat transfer. It can be used for both winter heating and summer cooling, and has not been applied in present air conditioning engineering. Compared with the traditional radiant cooling system, it has the function of dehumidification and is convenient for construction, installation and maintenance. Referring to relevant standards of Test methods for thermal performance of radiant cooling and heating unit, Radiant panel heat exchanger for cooling and heating, Technical specification for radiant heating and cooling, this paper is based on the thermal performance tests of the new terminal device, and evaluates the thermodynamic performance of the device thus giving convenience for type selection in engineering and making prospects in further improving in thermal performance.First of all, according to the standard design experiment plan, set up performance test-bed, according to the standard requirements to ensure the experiment devices, instruments and meters accuracy. Compared different terminal equipment standards, determine the heating, cooling condition standards for the experiment equipment. Then, according to the requirements of the standard of the terminal equipment cooling and heating load, calculate and analyze cooling and heating load, find that the standard cooling load was351.8W, the standard heating load was809.OW; then calculate the radiation heat transfer and convection heat transfer part, the proportion of radiation heat transfer and convection heat transfer is2:1. According to the results, derive the condensation rate calculation formula and fitting and simplified it then get the simplified formula of condensation flow applicable in engineering. Used the formula to make the condensate water line diagram, then briefly analyze the reason for the existence of the error. Then using the experiment data get the characteristic equation as the reference for engineering equipment type selection. Then, test the new terminal equipment import and export resistance under different flows. Through fitting the test results the relationship between water resistance and flow thus can be concluded and can give convenience for engineering hydraulic calculation and power equipment type selection. It is concluded that the impedance is808.OkPa/(m3/h)2.Finally, put forward that using unit the projection area of heat transfer as the thermal performance evaluation method. Compared with the different air-conditioning equipment such as radiation of the floor and roof systems, the radiator and fan coil, the results show that in heating condition, the unit projection area of heat transfer enhance about34.1%higher than that of traditional floor radiant system, enhance about34.4%higher than that of steel column radiator, about2.9%lower than that of cast iron column type radiator; in cooling condition, the unit projection area of heat transfer enhance about122.5%higher than that of traditional floor radiant system, enhance about100.8%higher than that of traditional roof radiant cooling system. The results show that this equipment is suitable for popularization and application in practical engineering.