Thermal Performance Study Of Assembled Capillary Ultra-low Temperature Radiant Heating Floor

Nowadays,assembled buildings have been widely used in many large buildings by virtue of its advantages of easy construction,saving consumables during construction and low waste waste production,capillary radiant heating system has also been marketed in China by virtue of its advantages of high comfort,low energy consumption and easy laying,but there are few studies on the modular production of capillary flooring,so this paper will synthesize the characteristics of both and propose an assembled Capillary ultra-low temperature radiant heating floor,this paper will study its thermal performance,for the later assembly of capillary ultra-low temperature radiant heating floor market to provide strong support.First of all,a detailed introduction to the form of capillary radiant heating end,summarize the advantages and disadvantages of capillary radiant end;through threedimensional diagrams,top views and other pictures of the way to show the composition of the assembled capillary low-temperature radiant floor system and the form of construction;the operating mechanism of the floor heat transfer and from the low-temperature hot water to the capillary wall,from the capillary wall to the floor surface,from the floor surface to the indoor environment of the three stages of the heat transfer process The detailed theoretical analysis is carried out.Next,the CFD research method,basic theory and Fluent calculation software used in the study are briefly introduced.Six models of assembled capillary low-temperature radiation floor with length,width and height dimensions of 600mm×300mm×60mm are established;the fluid domain and solid domain of assembled capillary low-temperature radiation floor are divided,and each boundary condition is set reasonably;then the mesh is divided;the simulation calculation is started after reasonable settings in Fluent,and the simulation results are compared with the theoretical calculation results The reliability of the software is verified by comparing the simulation results with the theoretical calculation results.Then the assembled capillary low temperature radiant heating floor different structural parameters(different capillary laying methods and different tube spacing),different water supply conditions(different water supply temperature and different water supply flow rate)two types of factors on the floor surface temperature distribution and heat transfer characteristics of the study.The results found that the capillary tube spacing are 20 mm,the water supply conditions are set for the inlet water temperature 308K(35 ℃),the flow rate of0.3m / s,U type,I type two laying the highest temperature area of the floor surface are in the supply and return water main location,capillary tube using I type laying method than the U type laying method of the floor surface temperature distribution more uniform,higher temperature;in The same water supply conditions,that is,the inlet water temperature 308K(35 ℃),the flow rate of 0.3m / s,the smaller the pipe spacing,the better the heat dissipation effect,the floor surface temperature distribution about uniform,and the greater the degree of influence on the floor surface temperature,that is,for the same supply water temperature rise,the smaller the capillary pipe spacing floor surface temperature rise value is greater;keep the water supply temperature of 308K(35 ℃)unchanged,respectively I model of the tube spacing of 10 mm,20mm,30 mm in five kinds of water supply flow rate conditions,the average temperature change of the floor surface simulation,found that the flow rate control in0.2m / s to 0.25 m / s between the floor surface temperature rise more obvious;keep the water supply flow rate of 0.3m / s constant,respectively,the tube spacing of 10 mm,20mm,30 mm It is found that when the water supply temperature increases from 32℃ to 36℃,the gradient value of the floor surface temperature increases gradually,especially when the water supply temperature increases from 32 ℃ to 33 ℃,the floor surface temperature increases most obviously.Then the U-shaped model was used to study the effect of capillary water supply temperature,water supply flow rate and tube spacing on the performance of assembled capillary low-temperature radiant floor heating through a three-factor,three-level orthogonal test design scheme.The results found that the three factors on the floor surface temperature of the degree of influence from largest to smallest: capillary tube water supply temperature,capillary tube spacing,capillary tube water supply flow rate,and the water supply temperature of 31 ℃,water supply flow rate of 0.3 m / s,capillary tube spacing of 30 mm water supply conditions can meet the design value of the floor surface temperature of 25 ℃,that is,with31 ℃ of low-temperature hot water can meet the heating requirements.Finally,the ultra-low temperature radiant heating system with solar hot water as the main heat source and household air conditioner as the auxiliary heat source is determined,and the area of solar collector is 28m2 and the volume of heat storage tank is 1.35m3.The system is analyzed economically,and the annual value of cost method is used to compare the heating system with solar energy as the heat source,household air conditioner as the auxiliary heat source and assembled capillary ultra-low temperature radiant heating floor as the end.Heating system and municipal heat network as a heat source,ordinary radiators as the end of the heating system for the initial investment,operating costs,annual cost value of the comparison,the results found that,in addition to the initial investment,solar energy as a heat source,home air conditioning as an auxiliary heat source,assembled capillary ultra-low temperature radiant heating floor as the end of the heating system operating costs and annual cost value are lower than the municipal heat network as a heat source,ordinary radiators as The former’s operating cost is 64.15% lower than the latter’s.The assembled capillary ultra-low temperature radiant heating floor studied in this paper uses solar energy as the main heat source and home air conditioner as the auxiliary heat source for the heating system with considerable economic benefits.