工業界每年消耗大量的電力來從事生產，一度電的生產將消耗約一磅的煤並釋放大量二氧化碳及廢熱，造成地球暖化日益嚴重以及空氣汙染、酸雨、臭氧層破洞和森林的破壞等各種負面影響，使得尋求替代能源及回收能源的方法勢在必行，在回收能源上近來許多研究方向開始紛紛轉往超臨界循環發展。本研究針對超臨界布雷頓循環根據美國Sandia實驗室報告指出其複循環熱效率可高達50%以上約為傳統郎肯循環的1.25~1.5倍。選用二氧化碳為工作流體的原因是基於其流體穩定性佳、臨界點條件低、取得來源難度低以及適用範圍廣，並且可減少環境中的溫室氣體。
然而此循環系統中的壓縮機與渦輪機需要經過精密的設計，為因應超臨界態的工作環境而選用了徑向式轉子作為內部元件，利用本實驗室邱豐壬學長當初使用ANSYS軟體建立的一套設計流程重新設計一可承受高溫高壓(12~18MPa、500~700K)設計點之渦輪機轉子，研究過程中首先利用Aspen Plus軟體進行循環站位分析得到系統總輸出及效率等。在轉子設計流程中設計點採用質量流率1kg/s、轉速30000RPM進行轉子設計分析，目標使14MPa高壓流體在經過渦輪轉子後壓力能夠下降到約8MPa左右且效率能維持在75%以上。
經過理論分析與設計流程後得到兩組轉子模型，經CFD模擬後壓降雖可達到目標預期但礙於設計的導引葉片效果不如預期也影響到轉子使其效率僅60%左右，在未來還需修改錯誤以增進轉子效率符合目標設計點條件

There is a lot of electricity power used for production by industry. degree of electricity produced would consume a pound of coal and release lots of CO2 and wasted heat which cause the global warming、air pollution、acid rain、ozone hole etc. It’s necessary to find the substitute and recycle energy. For recycle energy, many researches changed the direction to supercritical cycle recently. According to the report from Sandia, the America National lab, supercritical Brayton cycle’s heat efficiency can be over 50% which is about 1.25~1.5 times compare to the traditional Rankine cycle. The reason choosing CO2 as working fluid is based on its stability , low critical point condition, wide range of applications and greenhouse gas reduction in the atmosphere.
However the compressor and turbine of the system need to be designed precisely. To meet the work conditions of supercritical system, we choose the radial rotor as interior component. Utilize the design procedure built with ANSYS software by the lab graduated student Mr. Chiu to redesign a rotor which could take the high temperature and high pressure (12~18MPa、500~700K) design point. First using the software Aspen Plus to simulate the cycle stations and analyze the workout and efficiency. The design point of the rotor is 1kg/s of mass flowrate and 30000RPM of the rotor velocity to make 14MPa working fluid decrease to about 8MPa and keep the rotor efficiency over 75%.
After the theory analysis and design procedure there are two rotor models derived. Although the pressure drop conforms to the design point but the inducer’s effect doesn’t answer to the anticipation and also influence the rotor efficiency to be only 60%. The flaw will be corrected to improve the rotor efficiency and meet the design point.

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