パッケージエアコン 4 方向室内機内部における熱交換器を考慮した遠心ファン外径の検討

抄録

Air conditioners designed for an energy saving are required in a market. Improvement of a fan efficiency and uniformization of a velocity distribution in heat exchanger are necessary for improvement of a performance for energy saving. The velocity distribution and pressure-loss of heat exchanger and shaft power of the centrifugal fan were evaluated with Computational Fluid Dynamics (CFD). An appropriate diameter of the fan was determined by the result of the evaluation. Reducing the diameter to a certain value reduced the shaft power by approximately 4 % compared with a basic diameter. However, further reducing the diameter increase the shaft power in approximately 6 % compared with a basic diameter. These were caused by the change of the fan efficiency and the velocity distribution. In particular, we found the velocity distribution was related with the outlet height of the fan and a distance between the fan and the heat exchanger.