基于焦耳-汤姆逊效应的压力容器泄漏模型和数值仿真

Leak Model and Numerical Simulation of Pressure Vessel Based on Joule-Thomson Effect

提出了一种方法用来模拟在狭窄的裂纹中泄漏的高压氩气所发生的焦耳-汤姆逊效应引起的热传递过程。当前,压力容器的破前漏设计规范并没有考虑泄漏过程中此效应所导致的低温以及伴随的金属断裂韧性的退化。提出了一种单向耦合的模型来计算气体在泄漏中的压强和温度的降低,进而模拟出金属的温度变化;选择了准确度比较高的雷德利希-邝氏状态方程[1]来评估气体在泄漏过程中的温度;采用由Adams等[2]改进的Petukhov关系式[3]来评估气体的传热系数。对于起始温度30℃和压强91 MPa,模拟得到的测试板上裂纹周围的最低温度为13.8℃。设计了一个试验装置并在相同条件下进行测试得到的测试板上的最低温度与模拟得到的结果很好的吻合。

A method was proposed to simulate the heat transfer process of high pressure argon gas leaking through a narrow crack which caused by the Joule-Thomson cooling effect. Currently, Leak-before-Break （LBB） design codes for pressure vessels do not take into account of the subsequent low temperature depression and the drop in fracture toughness in the aftermath of a leak. A one-way coupling model was de- veloped to calculate the pressure and temperature drops of leaking gas. A heat transfer simulation then was performed to calculate the temperature distribution in the metal. The Redlich-Kwong （RK） equation with a relatively high accuracy was adopted to evaluate the gas temperature change during a leak. The modified Petukhov correlation by Adams et al. was employed to evaluate the gas heat transfer coefficient. For the initial temperature of 30 ℃ and pressure of 91 MPa,the simulated lowest temperature of the test plate in the vicinity of the crack is 13.8 ℃. An experiment rig designed and tested under the same conditions showed a good agreement with the simulation result at the obtained lowest temperature in the test plate.