Thermo-dynamic Performance Of Concrete Core Cooling Room

Radiant cooling system, with good prospects for development, has become one of priorities of air-conditioning systems in low-energy buildings and green buildings. As the building heat gains and operating parameters of cooling system have dynamic behavior, sufficient study and analysis about regulation of thermo-dynamic performance on indoor temperature in the concrete core cooling room are required to be conducted, and some general principles are to be formed, whose application in the design and operation of concrete core cooling system could help to achieve the energy efficiency of the air-conditioning system.The experiment platform was built to study the thermo-dynamic responses of concrete core cooling room induced by step change of external conditions, then a building model with concrete core cooling system was established by TRNSYS simulation software, and its reliability was verified using the experimental data through the Bland-Altman method. In addition, the thermo-dynamic performance indicators of the concrete core cooling room were identified, and the relationship between the thermo-dynamic performance indicators and their influence factors were obtained according to the extended analysis of the thermo-dynamic performance based on TRNSYS simulation models.The experiment results show that when heat gains and the supply water temperature have step changes, the room temperature, wall surface temperatures, discharge cooling rate of cold surface all changed significantly. In the initial response stage, the change rates of each parameter are greater, and then become smaller gradually, which change in the characteristics of first-order. However, the impacts of the water flow changes within a certain range on indoor temperature, surface temperatures and other parameters are not significant, thus the water flow is not recommended to be regulated in the range of 46%~218% of the initial flow.By the extended analysis of the thermo-dynamic performance, some conclusions are obtained: the degree of influence these three parameters on the dynamic thermal storage performance indicator is as follows: the impact of the type and the intensity of heat gains on the dynamic thermal storage performance indicators is not significant, which could be ignored in engineering applications; the degree of influence of the three factors, such as the heat capacity of passive thermal mass, the cooling system terminal and the air, on the dynamic characteristics weakened gradually in accordance with the above order; the functions of the dynamic response time constant and the change rate of indoor temperature are identified according to analyzing the relationship between the indicators and some parameters of passive thermal storage wall, which could be used to guide the operation of concrete core cooling systems.