Analysis On Air-conditioning Load Variation Characteristics Of A Mall In The Hot-summer And Cold-winter Region

A large comprehensive mall in the hot-summer and cold-winter region is selected tostudy in this paper. Firstly, the author obtains the air-conditioning load distributions andvariation characteristics of the mall through researching and testing. Secondly, the authorcomparativly analyses on the cooling load indexs and variation characteristics of the hot potrestaurant, KTV and clothing store based on the testing datas. Finally, the author makesquantitative analysis of main factors affecting for air-conditioning load of the mall and selectedshops by simulating with DB and the method of linear regression analysis. The results are:(1) The ratio of annual cumulative cooling load and heating load of the mall is0.62:0.38.Cooling load is mostly concentrated in June to August. Heating load is mostly concentrated inDecember to February. The peak cooling load of the mall occurs at18:00-20:00, and the peakheating load appeares at10:00. With the same meteorological conditions, loads on weekendsare greater than working days, and their hourly volatility are slightly larger.(2) Cooling load of the mall would reduce12.9W/m2, and heating load would reduce7.7W/m2, if interior design temperature was increased by1℃or decreased by1℃; Coolingload of the mall would reduce20W/m2, and heating load would reduce5.7W/m2, if peopledensity value was decreased by0.1p/m2; Cooling load of the mall would reduce5.5W/m2, andheating load would reduce2.1W/m2, if fresh air index was decreased by1m3/(h p).(3) The measured load of the mall is less than design value. Cooling load obtained bymeasurement was86to118W/m2, the proportion accounts for design value was46.5%to63.8%. Heating load was60to89.3W/m2, the proportion was60.5%to90%. The measuredsupply and return temperature difference of chilled water and hot water is less than the designvalue. The actual supply and return temperature difference of chilled water was2.6-5℃,1-3.4℃less than the design value (6℃). The actual supply and return temperature difference of hotwater supply and return water temperature is2.7-6.4℃,3.6-7.3℃less than the design value (10℃).(4) In terms of cooling load hourly variations, the clothing store is most similar to themall, while sub-periods of the hot pot restaurant is most visible, KTV and the hot potrestaurant have complementary trends. The air-conditioning system of comprehensive mallsshould be districted by functions, and making rational load allocation in the light of their loadvariations.(5) Cooling load of the hot pot restaurant, KTV and clothing store would reduce21W/m2,8.8W/m2,2.8W/m2, if interior design temperature was increased by1℃;cooling load of the hot pot restaurant, KTV and clothing store would reduce18.8W/m2,22.8W/m2,10.5W/m2, ifpeople density value was decreased by0.1p/m2; cooling load of the hot pot restaurant, KTVand clothing store would reduce4.1W/m2,4.2W/m2,2.6W/m2, if fresh air index was decreasedby1m3/(h p).(6) Through investigation and comparative analysis, peak cooling load relationshipbetween selected shops and the mall is: the hot pot restaurant (124W/m2)> the mall (118W/m2)> KTV (115.4W/m2)> the clothing store (72W/m2). The cooling load fluctuation of themall is less than the specific shops, and the occurrence difference of peak load is2to4hours.Compared with design handbook, actual cooling load index of the mall, hot pot restaurant andclothing store are smaller than the standard value, while KTV meet the standard value.The results can provide basis reference and guidance for optimal design andenergy-efficient operation of mall buildings air-conditioning system in the hot-summer andcold-winter region.