Energy Saving Research For The Combined Operation Of Air Conditioning And Hybrid Ventilation System In Large Space Building

It is fact that large space building has a high construction，high energy consumption andhigh energy saving potential. With the introduction of the theory and practice of greenbuilding, eco-building thinking has been going on in the field of large-space building. Todesign a hybrid ventilation through combining characteristics of large-space building andapplying ventilation principles, having combined operation of it and air conditioning insteadof air condition in the whole process. This ecological architecture technology can beconsidered to be a technical measure to reduce building energy consumption.Hybridventilation defined in the paper consists of thermal natural ventilation,mechanical exhaust airassisted thermal natural ventilation and direct evaporative cooling ventilation which be usedin building with less stringent with humility requirements.In the paper, the study object is energy-saving of air conditioning of one terminalbuilding in Guangzhou. Through using numerical simulation with Fluent software andreagarding temperature and wind speed in staff area as evalution parameters of indoorventilation,arriving at a conclusion: how the height from the ground and size height of theventilation inlet, exhaust pressure,indoor heat source and outdoor temperature to affectthermal natural ventilation and mechanical exhaust air assisted thermal natural ventilationbeing used in the large space building.The result showed that exhaust pressures will leadindoor air distribution, inhibiting the space thermal stratification; Enable mechanicalventilation natural ventilation, the forms of ventilation openings must meet certainrequirements; The height from the ground of ventilation inlet from is0.5m and its size heightis1.5m is the best form of ventilation openings; When the humidity requirements has less stringent in buildings, using direct evaporative cooling ventilation can get a further lowertemperature in the room.With mechanical ventilation rates, indoor heat souce and outdoor temperature is asvariable factors, using multivariate linear regression method to establish different ventilationinlet’s conditions of regression equations of temperature and wind speed in staff area.Through variance analysis of experimental result analysis, getting outdoor temperature andmechanical exhaust rates respectively, are the most significant factors affecting indoor airtemperature, wind speed in hybrid ventilation modes. Then combining adaptive model ofthermal comfort which taking into account with wind speed and humidity and hourlymeteorological parameters of transitional month in Guangzhou,to reach conversion values ofthe outdoor dry-bulb temperature between various ventilation and air conditioning modes inusing combined operation of air conditioning and hybrid systems in Guangzhou,also to get theavailable comfortable hours of hybrid ventilations modes.Finally,for the building with specific impact factors,analysising the energy consumptionmodel of main equipment in combined operation of air conditioning and hybrid ventilationsystem.Combining it with hourly load of building from DeST,to select the type of equipment.While calculating different main equipments under the various running strategies in May,Juneand October. This fact indicates that fractional energy saving in the best ventilation inlet’scondition of large space building can up to73.3%under using the combined operationstrategies. For the building with less stringent in humility requirements,it reduced to62.9%.The former and the latter can both meet fractional energy saving for60%optimizationof the request in green building evalution standard.The changes of form of ventilation inletwill significantly affect energy efficiency.