| Building heating and air conditioning energy consumption has been the main part of building energy consumption,up to 2/3,with the increasing shortage of energy,people pay more and more attention to air conditioning system energy saving.People's living standards continue to improve so the comfort requirement of the air conditioning system is also rising.In recent years,comfortable and energy-saving floor radiant air conditioning system is paid more and more attention.Different exterior walls and exterior windows are chosen as the research object in this study,and the influence of solar radiant heat transfer through different exterior walls and exterior windows on the radiant floor cooling system is calculated by theoretical formula.According to analysis the data,it is found that when the heat transfer coefficient of the wall is increased by 0.5 W/m2·K during 6:00 to 18:00,the floor cooling capacity of the room increases 1.25 W/m2?1.8 W/m2,the surface temperature increases 0.15 ?-0.32 ?;during most of day time with solar radiation effect,the transmittance of the exterior windows has a greater effect on heat transfer than the heat transfer coefficient,according to the calculation and analysis,the exterior wall and exterior window which are with less heat transfer of solar radiation and less influence on the cooling system are selected for the next study.In order to study the influence of solar radiation on the water flow rate and floor surface temperature of the floor cooling system,the determined external walls and windows with small heat transfer through above research are chosen for next study,cooling capacity and water flow rate and the temperature of floor surface are calculated with and without considering the effect of solar radiation on the condition of minimizing the impact of solar radiation.The difference of each parameter under the two conditions is analyzed to determine the extent of the influence of solar radiation on floor cooling system.The results showed that the average temperature of water supply and return during 2:00?12:00 is 19.5 0C without considering radiation and the average temperature of water supply and return during 13:00?1:00 is 16.5 ? to meet the 21 ? floor surface temperature requirements;According to this kind of water supply method,it can be concluded that under the condition of considering the solar radiation,the floor surface temperature is between 21 ? and 23.3 ? for 8 hours in a day,which cannot meet 21 ?floor surface temperature requirement.In the comparative analysis of this study,the influence of solar radiation cannot be neglected.However,in other researches,if exterior wall and window with less heat transfer are chosen in order to reduce the influence extent on floor cooling system which does not affect the research results,the solar radiation effect can be neglected.After analyzing the condensation problem,it is concluded that if the air-conditioning parameters are given according to the cooling parameters given in this paper,the indoor air humidity is not more than 67%to ensure that no condensation occurs on the interior of the system and on the floor surface.In order to study the impact of solar radiation on the indoor temperature field of the floor cooling system,fluent simulation was used to simulate the effects of solar radiation on indoor temperature field on the condition of without considering the effect of solar radiation and two rooms5 with different exterior windows considering the effect of solar radiation on the condition of three different floor surface temperatures of 20 ?,21 ? and 22 ?.By comparing the temperature in the level of 1.1m workspace,it is found that the highest solar radiation can increase the room temperature by 1.8 ?,even though the exterior window with small heat transfer is selected.Therefore,the influence of solar radiation cannot be underestimated. |
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