Imahigashi, S., Sakai, M., Yoshino, E., and Mitsuishi, Y., "Compact High-Efficiency 2-Layer Blower Fan for HVAC," SAE Technical Paper 2016-01-0193, 2016, doi:10.4271/2016-01-0193.
In recent years, the spread of eco-car has led to the demand for adaptation to low heat source, high efficiency and low noise in vehicle air conditioner. On the other hand, larger interior space of vehicle to assure passenger comfort is demanded, so that the car air-conditioner is required to be smaller. Therefore, we adopted 2-layer HVAC for the air conditioner which can respond to a low heat source. At the same time we have developed the compact high-efficiency 2-layer blower fan for HVAC in order to enable the 2-layer HVAC to be mounted on eco-car with smaller space than conventional HVAC.Generally, because axial flow velocity increases resulting from downsizing of the blower, the ununiform velocity distribution in the axial direction and the turbulent flow between fan blades occurs. It causes the efficiency decrease.To satisfy both downsizing and high-efficiency of the 2-layer blower, we have developed new technologies which can make the flow uniform between fan blades. The new fan is characterized by the inclined blade leading edge. This inclination of edge spread inside diameter of fan in the upper part more than the under part. Furthermore, we devised new scroll which is extended main flow part. This expansion of scroll prevents main flow from colliding with the scroll wall.We were able to reduce electricity consumption by 20% and noise by 4.5dBA with 40% of downsizing.By compact high-efficiency 2-layer blower, we were able to place 2-layer HVAC in the smaller space than ever before.