| 《Heating, ventilation and air conditioning design specification》 provides the days ofdaily average temperature for ages which are lower than or equal to5℃, which are greaterthan or equal to90days should be used only with areas central heating. The Yangtze Riveris hot in summer and cold winter zone where cannot satisfy with this condition, therefore itdoes not consider the traditional winter heating in this region. The785residents’ surveyshowed that more than90%of residents were used the split-type air conditioner in thewinter of2009in Shanghai, and the room was clear thermal stratification, human activatedin different locations, the temperature difference was relatively large, poor thermal comfort.So study the distribution of flow field and temperature field characteristics of the split-typeair conditioning room under different air supply parameters, understand the different formsunder the heating effect of split-type air conditioning room makes sense; for winterair-conditioning heating thermal stratification, establish the model and put forward a seriesof improvement measures has theoretical and practical significance for reducing the thermalstratification, raising people living area of comfort, and the installation、using、controllingand optimization of system development of the split-type air conditioner.In this paper, the actual mounted split air conditioner and air-conditioned rooms wereacted as the study objects, through experimental test chambers arranged in a temperaturethermocouples and data acquisition systems, thermal comfort test system, we studied theeffects of different variables under the indoor air temperature and flow field distributioncharacteristics, while testing the indoor environment related parameters which wasprovided accurate data for the numerical simulation. Study found that when the windshieldangle was90°, up and down of the room temperature stratification was more serious,reducing the angle of the windshield, the vertical height could improve the indoortemperature gradient; when the air speed increased from2m/s to3m/s, it couldeffectively reduce the thermal stratification in the vertical direction. By the thermal comforttest system for Z=0.1m, Z=1.1m, Z=1.7m height of the three measuring points,wecalculated PMV-PPD and reached a different operating conditions, the different heightlevels with different heat feel; and with the increasing height, PPD values increasing,indicating the ankle feels was the most sensitive to heat, but also the most difficult toachieve a satisfactory level.On this basis of the experimental test, we created a mathematical model and used fluiddynamics software Fluent to study the numerical simulation of the actual workingconditions. Simulation results showed that with the wind deflector angle (angle with the vertical plane) decreased from90°to60°, and then reduced to30°, the verticaltemperature difference is reduced in turn, when the wind deflector angle of30°, Z=0.1m, Z=1.1m, Z=1.7m height on the temperature exceeded the Z=2.7m height’stemperature, then reduce the angle of wind deflector has a significant effect for hot air tothe workspace; supply air wind speed increases by2m/s to3m/s,0.4℃temperaturedifference was reduced of the up and down; living in the area of the Z≤1.7m range,different positions on the air conditions needed differently; when reducing the range of themounting height of air and the indoor temperature setting in the reasonable area, it could bevery effectively to reduce the thermal stratification reasonably; further, by means of splittype air conditioner with a new air exhaust system integrated effect, it could effectivelyreduce the vertical height thermal stratification. It also provided a theoretical reference ofthe rational use of split air-conditioning and system optimization.By comparison between experimental value and analog value, verifying the feasibilityof theoretical model, and the basic theoretical model can express the actual situation,related research for split type air conditioning heating provides reliable theoretical basis. |
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