| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 101 === Abstract
Based on Taiwan governmental report, lung cancer is the most popular disease and has become the leading fatal factor for female patients during the past several decades. Because of the small smoking female population in Taiwan, thus it is inferred that this phenomenon primarily results from the cooking smoke and soot pollutions inside the kitchen, where usually utilizes the range hood as the ventilation tool. According to the market survey of range hoods in Taiwan, most driving force of range hood adopted the centrifugal fan, which not only limits the amount of flow rate but also generates high noise. Hence, a substantial demand for the high-performance, low-noise, and energy-saving range hood exists and motivates this research. Firstly, a two-stage axial-flow fan is chosen as the enhanced power to improve the maximum flow rate. After that, a comprehensive CFD analysis is executed to visualize the flow patterns inside the device and identify the adverse circulation and reversed flow for finding out the possible improvement alternatives. Therefore, this investigation intends to focus on the understanding and the improvement of the flow field inside the range hood by using the CFD simulation.
The CFD results show that the designed two-stage axial fan on the range hood yields a 738.2 CFM on airflow and a 28.6 mm-Aq maximum static pressure. Clearly, the maximum flow rate and energy efficiency of this innovative design is superior to those reported by other researchers of the range hood equipped with the centrifugal fans. Note that it is also found that the static pressure is slightly lower compared to the maximum pressure of the traditional designs. Nevertheless, this small pressure decrease is not essential since the range hood is operating under the free delivery condition (i.e. the maximum volume flow rate). In conclusions, this work successfully constructs a reliable tool to design a superior range hood with the novel two-stage axial-flow fan. Also, an important guideline for improving the design of range hood is attained and described in a rigorous and systematic manner.
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