Development And Application Research Of New Cooling And Dehumidification Terminal Equipment

With the continuous development of air-conditioning industry, people also gradually increase the requirements of indoor environment comfort. In recent years, radiant cooling with its high efficiency and energy saving, quiet and comfortable characteristics get more and more attention. High temperature cold-water can be used for radiant cooling, indoor design temperature can improve 1～2℃ than conventional air conditioning system, therefore the energy saving effect is obvious. But the application of radiation cooling system also has some disadvantages, the system needs to cooperate with the air supply system to achieve the purpose of dehumidification, if use the fresh air to undertake all of the indoor wet load, will cause the increase of energy consumption, especially in southern area of high heat and humidity, the application of the system is limited, is not conducive to energy conservation and efficiency improvement.In this paper, in order to solve the problem of radiant cooling air conditioning system when it apply in the high thermal and moisture area, design a kind of new equipment that using the principle of cooling dehumidification, can make up the disadvantages of radiant cooling capacity and reach the effect of prevent condensation.The equipment is applied to the radiant cooling room, to form the radiation cooling+displacement ventilation+new auxiliary cooling and dehumidification equipment three-in-one hybrid air conditioning system.This paper first carries on the design calculation of the new auxiliary cooling and dehumidification equipment, determine the pipes and heat exchange area. Secondly, use the CFD numerical simulation method, to study the dehumidifying and heat properties of the equipment, and the average rate of condensation law changes with the import of wet air speed under the different average surface temperature inside the device. According to the simulation results obtain the recommended operating parameters of equipment. Finally, put the optimized device in the radiant cooling and displacement ventilation room, inspect the operation and comfort effect of the equipment in the radiation air conditioning system.Through the simulation on condensation characteristics inside the equipment, we can know that the entrance of moist air parameters have great effect on the condensation rate of copper surface, the condensation rate first increased and then decreased gradually with the increasing of inlet wet air speed, the condensation law is basically the same under different cooling wall temperature;Due to the location of the outlet in the lower part of the room, considering the limit of displacement ventilation on the parameters of the supply air and requirements of indoor dehumidification, the outlet temperature of the equipment is controlled at about 18℃ and the speed of the 0.2-0.25m/s;An office of Ji’nan city as an example, the average indoor temperature can be reduced to 2.5℃, heat lamination height is about 1.5m, indoor air moisture content can be reduced by 13%, PMV-PPD index can meet the requirements of specification after using the auxiliary cooling and dehumidification equipment.The results of this study show that the application of the device can effectively achieve the supplementary cooling capacity and prevent radiation cooling condensation on the surface of the objective, make positive thinking to the application and extension of the radiant cooling air conditioning system in the high thermal and moisture area.