Numerical Calculation on Heat Transfer Performance of the Capillary Plane HVAC Terminal System

Nowadays as a novel terminal air conditioning system, the capillary plane HVAC terminal system is being researched in China. In this system the terminal capillary pipes are buried in the surface of the ceiling or the wall or the floor with the purpose-built grout, the chilled or heated water circulates in the pipes and exchanges the sensible heat with the indoor air by radiation and convection to make the indoor air parameters stable. The capillary mat terminals usually combine with dedicated outdoor air system and the latter takes on the indoor latent heat. Compared with the floor radiant heating system, the capillary plane HVAC terminal system has the advantages of saving more indoor space and any position installation. In this paper, with the method of numerical calculation the heat transfer performance of the capillary pipe buried in the grout are studied, the average temperature of the radiation surface and average heat flow density in summer and winter are figured out, and the influence factors such as: the pipe spacing, pipe embedded depth, pipe diameter, average temperature of the supply and return water, and design indoor air temperature are analyzed respectively. The optimal mode or trend under given conditions are proposed and the relations of the influence factors are summarized. All these above will be good theoretical references for the design and application of the capillary plane HVAC terminal system.