Research On Thermal Performance And Feasibility Of Capillary Radiant Air Conditioning System

With improvement of society and science, the requirement of people livingenvironment improves accordingly. Capillary radiant air conditioning system canprovide the comfortable environment as one type of air conditioning, and is used widely.But its cooling capacity is influenced by structure and operation parameters, so thispaper took one office building in Xi’an as research object, and built the heat transfersteady-state model from tube to room, then used the software named MATLAB tosimulate the influence of structure and operation parameters to thermal performance. Itis showed that the change of structure parameters, such as increasing thermalconductivity of pipe and laying material, the pipe diameter, or decreasing the pipespacing, and the change of operation parameters, such as decreasing water temperature,increasing water flow rate or indoor design temperature, all these may improve thesystem cooling capacity.In addition, this paper also built the heat and wet transfer dynamical models ofcapillary radiant air conditioning system, then used the software named MATLAB tosimulate the effect of some factors to the pre-dehumidification time and capacity, suchas indoor wet source, initial temperature and relative humidity, supply air volume andhumidity. It shows that if the indoor wet source, initial temperature and relativehumidity have no change, increasing supply air volume or decreasing supply airhumidity can shorten pre-dehumidification time, but the selection of supply air volumeand humidity should consider economy and energy saving. If the indoor air states havechanged, adjusting supply air volume and humidity in the same time is more effective toavoid condensation. In the last, the application of capillary radiant air conditioning system in sometypical climate cities are simulated, then analyzed the indoor air temperature andrelative humidity, discussed condense or not on the ceiling. As a result, capillary radiantair conditioning system is applicable in most regions of China if it combines withsupply air system, and it needs to pre-dehumidification in high humidity district. InUrumqi, using natural ventilation can avoid condensation and meet the thermal comfortrequirement. In Kunming, it is not necessary to do cooling design，so it is notapplicable.