LNG 플랜트용 프로판 냉매 원심압축기의 공력설계 및 전산해석적 연구

Abstract

Key Words: Aerodynamic Design(공력설계), Centrifugal Compressor(원심압축기), Tip Clearance(익단간극),CFD(전산유체역학), Propane Refrigerant(프로판냉매), LNG Plant(LNG 플랜트)초록: 본연구에서는4단으로구성된LNG 플랜트용프로판냉매원심압축기각단의설계점에대해상용코드를이용하여공력설계를하였다. 1차원공력설계결과와3차원유로형상의타당성은유동해석을통해확인하였다. 특히입구전압이높고회전수가큰4단압축기임펠러의유로와베인리스디퓨저내부유동에대한속도장, 압력장및엔트로피등의유동특성에대해고찰하였고, 아울러익단간극이유동장에미치는영향에대해서도알아보았다. 본연구결과는프로판냉매압축기의시스템제작에활용될것이며추후실제실험결과와비교하고자한다. 향후설계된프로판냉매압축기에대한LNG 플랜트에서의실증시험을통해구체적인설계결과에대한평가및설계개선이이루어지리라생각한다.Abstract: We design a four-stage propane-refrigerant centrifugal compressor for an LNG plant. Using a commercialcode, we aerodynamically designed the compressor at each design point of the corresponding stages. We estimated theone-dimensional aerodynamic design output and the three-dimensional shape of the impeller flow passage viathree-dimensional flow analysis. In particular, we discuss in detail the flow characteristics of the impeller and thevaneless diffuser passages of the fourth-stage compressor in terms of the velocity fields, the pressure, and the entropydistributions of the flow passages. We include the flow effects of the tip clearance flow, because at this stage therotating speed and total inlet pressure are higher than those at the other compressor stages are. We carried outperformance tests of the designed compressor stages using propane as a refrigerant in the LNG cycle. The practicalevaluation could lead to design enhancements in the future.