Study On The Jet Shape Of Air Distributor And The Flow Phenomenon In The Shroud Of The Outdoor Unit

The air conditioning system is involved to the air flow problem in many aspects. Among these problems, there are two details which are explored in depth in this paper. One is the jet shape of air distributor which is related to indoor air-flow organization, the other is the inner flow of the axial flow fan which is associated to the shroud of the outdoor unit of air conditioning system. The jet shape plays a leading role in the air flow of the indoor environment, and the shroud of the outdoor unit has an important influence on the internal flow and noise of the outdoor unit.Numerical simulation method is used to study the jet shape of air conditioner in winter condition, and it is verified by experiment in an air conditioning test laboratory. The results of experiments and simulations show that jet shape of air distributors is floating when there is no obstacle or attachment. The airflow is attached objects when there is wind pipe or other object. At the same vertical height, the analysis on jet velocity shows that the simulation results and the test results are in consistent with the trend about deduction of velocity. In this way, the reliability of the numerical simulation on airflow organization research is verified. This paper can provide the reference for the boundary conditions settings.With the height of the outdoor unit's shroud unchanged, effects of inlet diameter of the shroud outdoor on the axial flow fan in the flow and acoustic performance is studied. The following conclusions can be drawn. When the outlet static pressure is small, the flow rate of the outdoor unit is changed little with variation of the inlet diameter. In a certain range, with the increase of inlet diameter of the shroud, efficiency of axial flow fan increases slightly and turbulence intensity of the fan outlet reduces, surface acoustic power level of the shroud and the fan suction surface reduces, too. With the increase of the inlet diameter, the shroud inlet vortex core region decreases, its interaction with the fan tip vortex is weakened and their blocking effect on the passage recedes, too.Numerical simulation is used to study the influence of the different size notches of different locations, which is cause by assembly interference between the shroud and other components. The results show that, when notches are located near the middle wall and the central section of the outdoor unit, their influence on the flow rate is small, but the notches near the side entrance have a maximum impact on the flow rate. In particular, the cutting edge is close enough to the throat of the shroud, which causes the flow rate to decrease significantly. After the inlet shroud is cut, near the notches the corresponding low pressure district reduces, the amplitude of pressure fluctuation of corresponding monitoring points decreases. The control region of the tip vortex expand with flow passage area reduced; the noise of the outdoor unit increases.