Thermal Comfort Investigation And Heat Transfer Analysis Of C Agillary Network Radiation Refrigeration

As the social economy developed in high speed, people’s demand for in-door thermal comfort was lifted to a new level, and it also resulted in heavy consumption of energy by using air-conditioner. The traditional air-condition system still had some problems, such as energy loss of combining adjusting process of both temperature and humidity, mildew on the cold surface, blowing feeling caused by convection, noises and repeated installing of two environment adjusting system, etc. The increasing of comfort level would definitely cause a rising in energy consumption.Capillary network air-conditioning system was built basing on temperature and humidity independent control technology and long-wave radiation theory, combining with displacement ventilation. It could effectively improve in-door air quality, and utilized energy more efficient. Therefore, it.was a comfortable, energy-saving and eco air-conditioning system.In this paper, a heat transfer physic model of capillary network microenvironment was established, and used to study the influence of different tube range, material, temperature difference between supply and back water on the temperature distribution of capillary network radiation roof and heat transfer. A model of room using capillary network air-conditioning system was built and simulated by CFD software. The result of simulation provided temperature field and velocity field of this room under different roof temperature, air supply mode and air supply temperature. By using Matlab to calculate the PMV-PPD index, the human thermal comfort result in radiation air-conditioning system could be obtained. For valid all the works mentioned above, an experiment room was using to get the data of temperature field, velocity field and humidity. These data were compared with results of above model. And it proved the possibility of using numerical method to predict thermal environment of capillary network air-conditioning system.This study showed that tube range, materials, supply velocity and temperature played important roles in influencing roof s heat transfer capability. Optimum parameters could insure the roof had best heat transfer capability, and kept its heat flow rate above60W/m2. According to this study, PMV should be-0.5+0.5, which meant the PPD will be below10%; upper supply and bottom return showed the best performance; roof temperature was the core factor influencing human thermal comfort, when it was below the20℃, PPD will less than10%.This study solved some problems recently showed in capillary network air-conditioning system, and could provide reference for design and practice. The capillary network air-conditioning system showed a lot of potential in applying for high thermal comfort demand places.