Abstract: Perforated plate is an important throttling component inside high pressure reducing valve (HPRV). After superheated steam flowing through perforated plate, temperature difference is generated, and then thermal stress. When the thermal stress is large, cracks may be generated on the surface of perforated plate, which may cause failure. Flow fields of HPRV are investigated by CFD. Using the thermo-fluid-structure coupling method, the distribution of thermal stress in the welded perforated plate inside MSHPRV was studied, and then the parameters of perforated plate were optimized to avoid failure. The effects of structure type, advancing distance and pressure ratio on the thermal-mechanical stress distribution were investigated. Results showed that compared with end and head perforated plates, the inner perforated plate can reduce energy consumption obviously and obtain smaller thermal stress. The best conditions for avoiding failure of perforated plate were to choose the inner perforated orifice, advancing distance 2mm and pressure ratio 1.014. This research is scientific and can guide the safety design of perforated plate in the pressure reducing valve and other process devices.

Key words: high pressure reducing valve(HPRV), perforated plate, thermo-fluid-structure coupling analysis, thermodynamics, numerical simulation, computational fluid dynamics(CFD)

摘要： 多孔板是高参数减压阀中的重要节流元件。过热蒸汽通过多孔板时，会形成温度差，进而产生热应力。热应力较大时多孔板表面会生成裂纹，有失效可能。本文利用计算流体力学软件分析高参数减压阀内部流场，继而运用热流固多物理场耦合方法，研究了多级高参数减压阀中焊接孔板上热应力的分布，进而对多孔板进行参数优化以避免失效。重点考察了结构形式、推进距离和减压比对多孔板热-机械应力分布的影响。结果表明，相较于端部式孔板和封头式孔板，内部式孔板可显著减少能量消耗，并获取更小的热-机械应力。节流孔板避免失效的较优使用条件是选择内部孔板、表面推进2mm且压力比设为1.014。此研究具有科学性并可以指导节流孔板在减压阀等过程装置中的安全设计。

关键词: 高参数减压阀, 多孔板, 热流固耦合分析, 热力学, 数值模拟, 计算流体力学