Optimization analysis of structure parameters of steam ejector based on CFD and orthogonal test

One-dimensional theoretical methods are always utilized for analysis of performances of a steam ejector but they commonly have certain limitations. Numerical simulation and analysis were carried out by means of CFD method to the flow field inside a steam ejector for recovery of waste heat; moreover, the single-factor analysis was performed to see how the ejector was affected by those single-factors such as the diameter of the nozzle outlet, the distance between the nozzle outlet to the inlet of the mixing chamber and diameters of the contraction section of the mixing chamber and the diffuser chamber, respectively, while other conditions are fixed. Multi-factor analysis was then carried out to investigate the performances of the ejector and its structures were optimized by means of the five-factor and four-level orthogonal tests to gain the sensitivity for each factor to performances of the ejector. Results indicate that the optimized ejector has much better performances and the diameter of the nozzle outlet is the most sensitively influencing factor on performances of the ejector. This study may provide a new way of thinking for optimization of structure parameters of any steam ejector and have certain values for design and application of steam ejectors.