Research On The Simulation And Testing Of Ceiling Radiation-Displacement Ventilation Air Conditioning System

Displacement ventilation and ceiling radiation cooling/heating technology,integrating the collection ceiling heating, cooling, fresh air and life horizontal hot wateras an organic whole, is considered as an ideal air conditioning mode, which is widelyused in senior housing, villas, and public places. This paper introduces the principle andcharacteristics of Displacement ventilation and ceiling radiation cooling/heatingtechnology, a detailed description is made about its system characteristics, structure,technology characteristics, comfortableness and energy saving property.In order to know exactly the situation of the air conditioning system operation,the air conditioning system of a residential area in Jinan is tested, with in and out of thewater temperature, flow, and system power consumption measured. The results showthat air conditioning system has a better comfortableness while suffers a lager energyconsumption compared with the normal air conditioning systems. Based on thisobservation, a model of Ceiling radiation-displacement ventilation hybrid airconditioning system is set to do simulation research, taking the TRNSYS program forthe platform, and adopting the Loads and Structures module and HVAC librarymodules.A building model is established to do a simulation study about the cooling/heatingload, indoor environment of the building, with TRNSYS as a platform. By changing thethickness of the thermal insulation layer in the outerbuilding envelope, the effect ofouterbuilding envelope on the annual energy consumption of air conditioning system inJinan is analysed. It is found that the outerbuilding envelope has a great influence onconsumption of air conditioning system. When30to50mm thick expandingpolystyrene board insulation layer structure is adopted, the energy saving rate of the airconditioning system is about77.2%~83.9%.Through the model of the air conditioning system, the supply/return watertemperature of evaporator and condenser, and the coefficient of performance (COP) insummer is obtained. Compare the TRNSYS simulation results with the measured data,the result is consistent. On this basis, four common design working conditions are given, the power consumption and indoor thermal comfort of the air conditioning system forthe four conditions are simulated in constant flow conditions, providing a theoreticalguidance for the system design and spread.