A Investigation Of Thermal Properties And Hydraulic Calculate Method Of A Capillary Air-conditioning System

Building energy efficiency is an effective measure to ease the energy shortage, and promote sustainable economic development in China. The capillary air-conditioning system, as a comfortable and energy saving system, attracts more attention in pratice nowadays, and the research on it needs to be improved.This paper analyzed the heat transfer process of the planar capillary cooling air-conditioning system, made a reasonable assumption and simplification and established a two-dimensional mathematical model of steady-state heat transfer. The mean temperature of the panel surface and the heat flow of unit area are the most important parameters of this system. In this paper, the MATLAB calculation program programmed by a micro-body heat balance method focuses on the impact of ceiling temperature field and the cooling performance of the factors such as temperature of supply water and return water,the pipe space and the water flow, then obtained the heat transfer per unit listed in a table, which provides a calculation basis for the system design.When the capillary air-conditioning system used for cooling or heating, determine the system pipe diameters and pressure loss is the most basic and most important step in the process of hydraulic calculation. It gained the Pareto Optimal Solutions of Multi-objective Optimization based on Genetic Algorithm, calculated the Optimal specific frictional resistance,optimal pipe diameter and velocity of the main pipes, in order to reduce the pipe pressure loss per unit length and to save the tube under the certain water flow.The research provided numerical parameters for the Capillary network's design and application. It analyzed the flow characteristics in the capillary network, investigated the method of the hydraulic calculation. Chose a suitable pressure loss formula according the flow state in the network to calculated the loss of frictional resistance, and the net loss of seats in the calculation of local resistance is more important. Differences in nets style has a great impact on the loss of local resistance as a percent of the loss of frictional resistance, then studied the percentages. A calculating program was developed for the system, which supplied to the basic calculations for the system's design.Finally, it calculated the actual situation on the basis of above theoretic outcome of researches. By setting up a test room, it measured the temperature of roof surfaces,heat transfer per unit area,indoor air temperature and the pressure less of the capillary networks in different winter conditions. By comparing the experimental results and theoretical calculations, the heat transfer model is correct and the hydraulic calculation method can be used in the engmeering.