Study On Prediction Model Of Refrigeration Performance Curve Of Open Radiant Ceiling

Radiant ceiling air conditioning system is a kind of air conditioning system which mainly uses radiation heat transfer and is accompanied by convection heat transfer.As a new indoor thermal environment control system,radiant ceiling air conditioning system has been paid more and more attention in recent years due to its excellent energy saving and thermal comfort.However,due to its insufficient cooling capacity,the popularization and application of radiant ceiling air conditioning system in China are severely restricted.In order to improve the cooling capacity of the radiant ceiling,the concept of the open radiant ceiling was proposed for the first time in China,and the feasibility of the open radiant ceiling to improve the cooling capacity was verified through experiments.The experimental study showed that:(1)When the area of the radiation plate of the open radiation ceiling is75% of the room area,compared with the closed radiation ceiling,the cooling capacity per unit area is increased by 49.4%-64.4%,and the total cooling capacity is increased by12%-23.3%.Expansion simulation was conducted on the basis of verifying the accuracy of the model.The influences of room area S,room height H,the ratio of radiation plate area to room area 1,the ratio of wet circumference to perimeter of radiation plate 2 and the distance between radiation plate and roof d on the cooling capacity per unit area of open radiation ceiling were studied.The simulation study showed that:(2)The total cooling capacity per unit area of the radiation panel increases with the increase of the room area.When the room area is 36m2,the cooling capacity per unit area of the radiation panel increases by 16%-23.8% compared with that when the room area is 16m2.(3)With the increase of room height H,the cooling capacity per unit area of the radiation plate basically remains unchanged;(4)As the area ratio of the radiation plate increases,the cooling capacity per unit area of the radiation plate first increases and then gradually decreases with the increase of the area ratio of the radiation plate.When the area ratio 1 of the radiation plate is 0.65,the cooling capacity per unit area of the radiation plate reaches the maximum.Compared with the radiation plate area ratio of 0.2 and 0.8,it increases by13.6%-19.6% and 4.3%-7.1% respectively.(5)The cooling capacity per unit area of the radiation plate first increases and then tends to be stable with the increase of the wet peripheral ratio of the radiation plate.When the wet peripheral ratio is 2.5,the cooling capacity reaches the maximum,which increases by 14.1%-16.5% compared with that when the wet peripheral ratio is 1.(6)As the distance d between the radiation plate and the roof increases,the cooling capacity per unit area of the radiation plate first decreases and then tends to be stable.When the distance between the radiation plate and the roof is 0.4m,the cooling capacity of the radiation plate decreases by 8.5%-14.4% compared with that when the distance is 0.1m.Collection at the end of the simulation,the simulation data as a return data,using SPSS software to arrange the return of the data regression analysis,the definition of radiation in ASHRAE condole carries on the coefficient of cooling performance curve correction,the condole top open radiation cooling performance curve prediction model,when open radiation air-conditioning in engineering applications,According to this prediction model,the refrigeration performance curves of the open radiant ceiling in different sizes of rooms and different installation types can be predicted,so as to determine the best area,open type and installation distance of the radiant plate.This topic is of great significance to improve the cooling capacity of the radiation ceiling,and has a guiding role to the application of the open radiation ceiling in engineering.