Study On Characteristics Of Radiant Floor Cooling Loads And Optimization With High Temperature Chilled Water In Xi’an

In our country, at present the application of radiant floor heating system is start, butthe radiant floor cooling system is still at a research stage, and the reference material fordesign only come from abroad. Because of radiant cooling and heating have large arearadiant heat-transfer characteristics, natural source such as phreatic water, evaporatingcooler etc are likely as the cold and heat sources of radiant floor cooling and heating.The use of natural source can save refrigeration equipment, reduce cost, save energyand not pollute environment.In the existing floor heating design conditions, using finite element analysiscarryed out numerical computer simulation to two-dimensional heat conductiondifferential equation of radiation floor, optimizing the radiant floor heating and cooling.The influences on the ground temperature and comprehensive heat flux were researchedby this method, such as the supply and return water average temperature, thickness offiller layer, the tube space. The cooling ability and condensation problems of floorcooling system were analyzed and design parameters of floor that does not getcondensation and surface heat flux were obtained. Study on the tube space for200mm,the supply and return water average temperature for15℃, in this design condition, thelowest floor temperature is19.92℃,the average floor temperature is20.36℃, thecorresponding heat flux density is36.9w/m~2.Set up a mathematical model for indoor thermal environment on the base ofanalyzing enclosure heat gain and heat loss of each envelope. Under the above designparameters of the floor, building energy consumption simulation software EnergyPluswas applied to study the thermal environment of the residential building room with radiant floor cooling with natural high temperature chilled water system in the entiresummer in xi’an. To provide the basis for evaluating the thermal environment of roomwith this system. The result showed that the indoor temperature of radiant floor coolingwith natural high temperature chilled water system are under30℃in the early(May15-July10) and end (August10-October1)cooling. Due to the influence of the meanradiant temperature, it can satisfy the human thermal comfort. In the middle(July10-August10) cooling, single-floor radiant cooling system can not satisfy the humanthermal comfort, need to add auxiliary air-conditioning.Simulated the energy consumption of the conventional air conditioning system insummer, and compared it with the radiant floor cooling with high temperature chilledwater system. The result showed that the radiant floor cooling with natural hightemperature chilled water system has great energy saving potential. In the early and enddays cooling, radiant floor cooling with natural high temperature chilled water systemcan satisfy the human thermal comfort. Therefore, no cold energy consumption. Only inthe middle cooling, this system can not satisfy the human thermal comfort, need to addauxiliary air-conditioning. For the whole of the cooling season energy consumption canreduce about91.4%.