The Simulation Of Heat Transfer Characteristic Of Concrete Radiation Terminal And Application Reaserch

Concrete radiant air conditioning is widely used in residential heating, large space cooling and heating, etc, which is a way different form the traditional air conditioning. The terminal of concrete randiat system has big theramal capacity, and it also has large laying area. Under steady-state conditions, the concrete radiant terminal mainly heat room with long-wave radiation. It has a larger angel factor on hunman body. In the condition of changing indoor or outdoor thermal condition, or intermittent heating condition, the characteristics of heating storage and release of concrete radiant terminal can stabilize the fluctuations of indoor thermal environment, and maintain indoor thermal environment. At present, the comparison between randint terminal and convective terminal is mianly simulation. And the research on heating storage of concrete buildings mainly ingnores the heating storage and release characterisatics effect on indoor thermal environment, the application and simulation of combination between concrete terminal and corresponding heat resource is less. This paper mainly studied the above problems, make comparion between radiant terminal and convective terminal on thermal confort and heating load, research on the application of concrete radiant terminal and corresponding matching heat source.By the way of block discrete of concrete radiant terminal, the variation of flow heat medium in the duct of concrete randiat terminal is considered, then the heat transfer model can be established. By the way of steady-space method, the block discrete of building envelope is used to establish the matrix equations of heat transfer. Combining the heat transfer modle of concrete radiant terminal and bulding envelope, the steady state simulation and unstable-state simulation can be calculated.The equivalent heat loss temperature of building envelope is put forward. The relative vatiation coefficient △t_loss/△t_op is based on the equivalent heat loss temperature and human operative temperature, which can be used to compare the steady state heat transfer characteristics of different terminals. The smaller relative vatiation coefficient △t_loss/△t_op means less heating load at the same operative temperature.As to the application of concrete radiant terminal and corresponding matching heat source, two application cases are studied. Combining concrete radiant terminal with city central heating network and using appropriate the on-off control strategy can minimize the return water temperature and improve the energy efficiency. Combining the concrete radiant terminal and solar heat source can constitute distributed heating system, which can be used in Qinghai Tibet Plateau with rich solar energy resources. In this heating way, the indoor room tempreture can maintain above 17 ℃, the varation of indoor room temperature is smaller with good thermal comfort. Moreover, the reaserch on the heat transfer process of distributed heating system is maked, and the strategies of optimizing operation improvement are proposed to get better effect.