Climatic Zoning For The Design Of Air Conditioning Systems

At present,there is a gap between early design stage and equipment selection/design in the later stage of air conditioning systems.In these two stages,design parameters which are acquired under particular condition,such as peak load and rated condition,are considered only.And no distinction is made between sensible and latent heat parts.To deal with these problems,relevant climatic zoning researches have been made.These researches consider the diversity of working conditions faced by the design of air conditioning systems to a certain extent,so in the design stage the estimated load matches better with the cooling/heating capacity compared to traditional design method.However,there are still some defects in these studies.Temperature parameters are usually taken as the main or only zoning index,while humidity parameters are ignored.Temperature-based climatic zoning cannot guide the design of air conditioning systems in dealing with latent load.A few studies involve humidity parameters,but are only targeted for some specific air conditioning systems,so the scope of application is limited.To tackle these defects,this paper focuses on the climatic zoning for the design of air conditioning systems.First,"humidity-based cooling degree-day" and "freezing degree-hour" were selected as the humidity indices of climatic zoning,and were used to make humidity climatic division of China during cooling period and heating period,respectively.The result showed the regional influence of humidity on the air conditioning system design,and further proved the importance of considering humidity in the design.Then locations where cooling was needed were discussed.96 cities were selected.Building energy consumption simulation was conducted tocalculate the load characteristics for every chosen city.Based on the simulation results,mean sensible heat ratio and mean total load were were used as zoning index.Five comprehensive climatic zones were made.Different demands for air conditioning systems in each zone were analyzed.On the basis of comprehensive climate zoning,hourly sensible heat load and hourly latent heat load of representative cities in each zone were investigated.The characteristics of load range and load density in each region were compared and analyzed on the hourly load figure.The load characteristics were connected to the output capacity plane of the air conditioning systems,and a new "plane-to-plane" air conditioning system design procedure,which is different from the traditional "point-to-point" design process,was proposed.