Analysis And Research For Some Problems Of Radiation Refrigeration System In A Building

With the development of society, the policy of sustainable development of energy saving and emission reduction has been considered as a primary task in all the walks of industries. It is essential to air conditioning industry which consumes the major energy in the construction industry. Floor radiation systems combined with displacement ventilation which can be used both in winter and summer and helpful to develop new sources of hot and cold, has been more and more attractive. In addition, the radiant floor heating system has a earlier development than the cooling system, and has a series of corresponding measures of technical norm, there are many cases available for reference and research in lots of cities. But the theoretical research on the radiant cooling system is less, and there is no mature norm to follow now. So its designers maily follow reference on heating system, and the problems are inevitably arisen. In this article, some of the problems on a case of radiant floor cooling system has been analyzed, which can provid some theoretical help for the future design and construction.Based on the previous theoretical studies, at first, the author has made a brief summary for heat transferring process of the radiant floor cooling and displacement ventilation systems. Some simplified mathematical and physical models are presented, which deepen understanding for the whole system, and a theoretical basis for the analysis of the actual project is provided in the fourth chapter. Then, those problems in practical engineering are analyzed by pracrical measure, and the reasons of the problem that the hot above and cold below indoor have been found as the following three points: Firstly, the cooling capacity of floor is not good; Secondly, the uneven distribution of heat inhibits its role of thermal plumes; Thirdly, due to no additional air vent, air can not flow regularly, hot air of the upper can not be discharged in time. Consequently, the room becomes more hot.This thesis has focused on the influence of the air distribution on thermal comfort indoor, and has used the Airpak2.1 simulation software to simulate 305 room without exhaust outlet and a virtual room with additional air vent with regard to the third reason. The result shows that simulation results of 305 room with no exhaust port is consistent with the actual measurement. Finally, air distribution of two cases, velocity field changes in the indoor, vaule of PMV and value of PPD have been analyzed, showing that the room with an additional air outlet is more comfortable than the room without exhaust outlet. So it is concluded that additional air vents will be positive to the distribution of room airflow. But this thesis still has some shortcomings. Limited by engineering practices, the 305 room with additional vent can only be simulated at first. More actual engineering studies should be done in the future.