Throttling components effect on aerodynamic performance of superheated steam flow in multi-stage high pressure reducing valve

Superheated steam (SHS) is widely used in various integrated energy systems. Multi-stage continuous-resistance perforated sleeves and n-stage adjustable-resistance perforated plates are the two key throttling components in the multi-stage high pressure reducing valve (MSHPRV) to control SHS flow. However, no general design guidelines on the relationship between aerodynamic features and throttling components were found. In this paper, the fluid dynamics of SHS flow are revealed by using both the experimental and numerical methods. Then, the effects of typical parameters on the pressure drop and Mach number are investigated. Furthermore, an orthogonal design method with array L9(34) is adopted to achieve the optimized design of throttling components. The results show that SHS flow in the MSHPRV is transonic and shows linear flow rate. Here, the smaller valve opening (L/Lmax), chamfer radii (r/D0) and the larger sleeve diameter (D1/D0) relate to the larger pressure drop and smaller Mach raise. Moreover, the n stages achieve n-level pressure drop and Mach raise. The smaller plate diameter (D2/D0) and the larger pressure ratio (π) relate to larger pressure drop and smaller Mach raise. Finally, optimized design of throttling components is achieved with plate diameter D2/D0 = 0.4, plate stage n = 3, sleeve diameter D1/D0 = 0.8 and chamfer radii r/D0 = 0.1.