Study On Air Supply Mode And Structure Optimization Of Fan Coil Plus Fresh Air System In Small Spaces

With the gradual advancement of urbanization,more and more building clusters in the city are rising.The large-scale building cluster provides the necessary guarantee for people's daily life and work.However,due to its extremely high building density and maximum space utilization requirements,it has been difficult to meet the people's increasing requirements for indoor environment comfort and air quality simply by relying on natural wind to regulate the indoor environment.Therefore,the ventilation and air conditioning system in various buildings is extremely important.This research is mainly aimed at small work spaces,to simulate the air supply mode of the fan-coil unit and the fresh air system.There are four types of dual-system air supply:dual-system independent side air supply,dual-system independent top air supply,dual-system mixed side air supply and dual-system mixed top air supply.And through the establishment of mathematical models,physical models,meshing and other research steps using FLUENT numerical simulation software for CFD numerical simulation analysis and research,to obtain the temperature field,velocity field,water vapor mole fraction field and PMV index.Finally,analyze the simulation results and find out the optimal air supply method of fan coil and fresh air system.The results show that the temperature field of the independent side air supply meets the design requirements,but the speed field does not meet the design requirements.The spatial temperature distribution of the independent top air supply is poor.Due to the high wind speed in the breathing area of human head,the velocity field of the mixed side air supply method does not meet the design requirements.The temperature field and velocity field of the mixed top air supply meet the design requirements,but the PMV value is not good.In view of the poor PMV value of the mixed top air supply,the end diameter of the mixed air pipe was reduced.When the diameter of the end mixing pipe decreases to 230mm×230 mm,the wind speed of the supply air increases.The PMV went down to-1.27.So it's not feasible.When the diameter of the end mixing pipe increases to 270 mm×270 mm,the wind speed of the supply air slows down and the PMV value increases to-0.26.Therefore,it is believed that this scheme can effectively optimize the thermal comfort of the supply air of the fan-coil plus fresh air system.Finally,the economics of the fan coil plus fresh air system are analyzed.It mainly includes the construction cost of the fan coil,the construction cost of the fresh air system and the operating cost of the dual-system.According to the calculation of the operating cost of the dual-system,when the small-scale working space with a spatial scale of 5 m × 6 m × 3.5 m selects the mixed air supply mode of fan coil and fresh air system,the annual electricityconsumption of the room is 1770.08 k W.h,equivalent to 725.7 kg of standard coal...