Analysis And Study Of The Heat Transfer Characteristics Of Concrete Radiant Ceiling In Winter Heating Transfer Conditions

With the society focusing on building energy efficiency, radiant ceiling system as the form of air conditioning energy saving effect has been paid more and more attention by the experts.Meanwhile it has competitive advantages in energy conservation, thermal comfort and environment friendliness. The heat transfer process of the radiant ceiling is more complex, and the research of this aspect is still not enough, this paper studies the heat transfer performance of the radiant ceiling through the method of experimental research and theoretical analysis.First, the paper introduces the principle, the structure, the adv antages and disadvantages of the radiant ceiling system, a quick and easy calculation heat transfer mathematical model was introduced for radiant ceiling, which is modified to improve the calculation accuracy. Secondly, the experiment platform for the concrete radiant ceiling system is built up, through which test the thermal performance of concrete radiant ceiling. And through experience, datas are obtained, such as indoor air temperature and humidity, ceiling temperature, f loor temperature, and wall temperature. By analyzing data of experiment, the heat storage performance, the thermal response characteristics, and the relationship between the heat transfer performance and parameters has been found, then analysis experimental datas to find the impact on radiant ceiling when the parameters of ceiling heat transfer performance changes.Finally, the celing temperature and heat transfer were compared between model calculation results and the experimental data measured values. Compared with the results of thermal performance test,the mathematical model was reasonable with a maximum error less than 5.15%.According to the results of model and experiment, in the constant flow condition,heating capacity of the ceiling increases as the temperature increases, meanwhile heating capacity decreases as the heat exchange coil spacing increases. Factors affecting the heat transfer performance of radiant ceiling were analyzed. Radiant heating heat transfer is at the proportion of the total amount of heat exchange more than 70%. When the water temperature rises, the proportion of radiation heat transfer was reduced, while the convection heat transfer rises. With the same water temperature, the smaller tube pitch, more heating transfer the radiant ceiling will get and the ceiling temperature distribution will be more uniform and easier to reach the interior temperature, which increases comfort room. so it should not let the heat exchange coil spacing too large.the ceiling temperature becomes higher with the increase of indoor ai r temperature, but the amount of heating by ceiling becomes lower; when the buried pipe spacing becomes larger, the ceiling temperature and the heating capacity of the ceiling become lower, so the buried pipe spacing should not been taken too large; the ce iling temperature and the heating capacity of the ceiling become lower with the increase of the depth of buried pipe, but the impact is not significant; the buried pipe diameter and the outdoor air temperature has little effect on the heat transfer perform ance of the ceiling.