Research Of Stack Effects Of A Super High-rise Building With Air Conditioning In Winter

In1972, the international conference of the high-rise building presided in the UnitedStates, where it was explicitly pointed out that the building more than40layers or abovethe height of100m is defined as a super high-rise building. High-rise building will makethe stack effect worse in winter, increase the energy consumption of the wind infiltration,increase the difficult of the door switch and other issues, these issues are detrimental tobuilding energy conservation and the proper use of ultra-high-rise buildings. Since the21stcentury, high-rise buildings appear constantly, and people pay more attention to high-risebuildings.In this paper, based on a super high-rise building under construction in Xi’an, therelated research was conducted by numerical simulation method, and this paper analyzedthe formation of stack effect in super high-rise buildings, the effecting factors andproblems that it brings out. The full-size physical model of the building was built by CFD,and the numerical simulation was realized under thermal pressure individually,and boththermal pressure and wind pressure simultaneously by changing the boundary conditionsand parameters of the model. The temperature distribution, velocity distribution andpressure distribution in the air conditioning rooms in the building and the shaft flow fieldwere calculated. By numerical analyzing on simulated results of the two cases, someconclusions could be obtained as follows. Due to the air supplying by air-conditioning,there is no external cooling air infiltrating through the exterior walls and the gate of thebuilding into the building, but only exuding. Under the effect of thermal pressure, theinternal and external pressure difference in the air conditioning room increases graduallywith the increase of vertical height. The absolute value of pressure difference on both sidesof the elevator doors (chamber side was relative to the elevator shaft)increasesprogressively with the increase of distance to neutralization boundary. Compared with theother layers, the absolute value of the pressure difference in the first floor was themaximum, which affected the normal switch of the elevator door. In the combined actionof thermal pressure and wind pressure, the air only exudes outside the rooms, and the internal and external pressure difference in the air conditioning room on windward andleeward increases progressively with the vertical height, while the pressure difference ofthe air conditioning rooms on windward each floor is smaller than that under thermalpressure, and the pressure difference on leeward is greater than that under heat pressure,and the absolute value of the pressure difference on both sides of the elevator doors(chamber side was relative to the elevator shaft) increases progressively with the increaseof distance to neutralization boundary, which however did not affect the normal switch ofthe elevator door.