某水下热动力系统热爆事故的润滑失效原因分析

Analysis on Lubrication Failure Reason of Explosion Incident in Underwater Engine System Tests

针对某水下热动力系统换速试验中多次出现的旋转燃烧室头部的热爆事故,基于流体力学、传热学以及数值计算的理论和方法,充分考虑了密封环节在整个系统中的工作环境变化,给出了一种关于旋转密封失效原因的工程分析方法。得出以下主要结论(1)缓慢的系统升速过程不会引起摩擦面处温度的超调,系统的安全性可以得到保证;(2)过快的系统升速过程会造成摩擦面处的温度超调,超调量随换速过程的加快而增大,且较大幅度的温度超调会造成润滑失效,从而引发热爆事故。根据以上分析将系统过渡过程放慢,热爆事故得以有效地避免,多次热车试验证明了文中理论和分析的正确性。分析方法和采取的措施已经应用于工程实践。

Aimed at the explosion incidents of rolling combustion chamber head happened in the rotating rate changing tests of an underwater engine system, by considering the changing of work condition for the sealing subassembly, an engineering method for analyzing the reasons of rotating sealing failure was put forward based on hydrodynamics, principles of heat transfer and numerical calculation method. Some important conclusions were got, such as: 1. Slow rate increasing process of engine system does not make the temperature of friction surface overshoot and the system can work in security. 2. Too fast rate increasing makes the temperature overshoot. The overshooting increases when the rotating increasing process is expedited. The big amplitude of temperature overshooting can make lubrication failure happen so that the explosion incident is occurred. The result of engineering practice shows that when postponing the rotating increasing process based on these analysis conclusions, the explosion incident is avoided.