基于研制阶段多源信息的大推力氢氧发动机可靠性评估方法研究

Large thrust hydrogen-oxygen engine, as the "heart" of a heavy rocket, must be highly reliable. The reliability of hydrogen-oxygen engine in our country is verified mainly by components performance tests and validation of engine system test, which often results in the exposing of components defects when the system tests are carried out. Then the defects are corrected to produce revised components, which are integrated into system, and system tests are again carried out. As the increasing thrust level of future engines, this method will lead to unacceptable delay in the development period and increasing of development cost. Therefore, there are urgent desires for quantitative reliability evaluation in engine development, to help identify components defects as early as possible. However, the quantitative reliability evaluation of engine components and system in the development is faced with small sample size, very few failures or even no failures. To solve this problem, this project researches on methods to evaluate the reliability of the component by using the test data. Then further researches will be carried out to explore the methods of fusion multi-source information, such as of similar components data, simulation data, to evaluate component reliability. Based on foregoing researches, combining with multi-source information as the test data of the engine system, similar system data, the engine system reliability evaluation method is to be explored. The research results can provide techniques to evaluate the reliability design and growth for large thrust hydrogen-oxygen engine in development, which is of great significance to the development of the aerospace industry.

作为重型火箭 “心脏”的大推力氢氧发动机，必须具备高可靠性。我国氢氧发动机的可靠性主要依靠研制过程中组件性能试验和发动机整机状态的验证试验来检验，常常出现在整机试验时才开始暴露组件的缺陷，进而反复改进、整合到系统进行试验验证的现象。随着未来发动机推力量级的不断增大，这种方法将导致研制周期的拖延和研制成本的大幅增加，因此迫切需要在发动机研制阶段开展可靠性的定量评估，尽早发现组件缺陷。而目前的发动机研制阶段的组件和系统可靠性的定量评估面临试验小样本、极少失效甚至无失效的难题。因此，本课题首先研究利用研制试验数据来评估组件可靠性的方法，进一步研究融合相似组件数据、仿真数据等多源信息来评估组件可靠性，在此基础上，结合整机的试验数据、相似系统数据等多源信息，研究发动机系统的可靠性评估方法。课题研究成果可以为我国在研大推力氢氧发动机的可靠性设计和增长提供评估的技术手段，对航天事业的发展具有重要意义。

大推力氢氧发动机要求研制阶段能够保证其高可靠性的要求，但是现有的发动机研制过程中往往只有整机试验时才开始暴露组件的缺陷，进而反复改进、试验验证，耽误研制进度、增加研制成本。针对这种现象，因此迫切需要在发动机研制阶段开展可靠性的定量评估，尽早发现组件缺陷，而目前的发动机研制阶段的组件和系统可靠性的定量评估面临试验小样本、极少失效甚至无失效的难题。因此，本项目首先研究了利用研制试验数据来评估组件可靠性的方法，进一步研究融合相似组件数据、专家判断等多源信息来评估组件可靠性，在此基础上，结合整机的试验数据、相似系统数据等多源信息，研究发动机系统的可靠性评估方法。项目研究提出了分组加速试验和分阶段研制条件下组件可靠性评估方法，基于专家判断和不同类型研制试验数据的组件可靠性评估方法，系统剩余寿命预测的数值计算方法，初步探索了系统可靠性鉴定试验方案的推导方法。项目研究提出的方法应用于发动机阀门、涡轮泵等组件在研制过程的可靠性评估，以及可靠性鉴定试验方案的制定。经过与传统方法评估结果的对比，项目研究提出的可靠性评估方法精确度更高，置信度更高，推导出来的可靠性鉴定试验方案的两类风险更小、时间更短。研究成果可以为我国在研大推力氢氧发动机的组件可靠性评估提供评估的技术手段，能够解决产品在多组加速寿命试验中存在零失效、分阶段研制过程中存在前一阶段有失效、后一阶段无失效以及两个阶段均无失效的情况下准确评估其可靠性的难题，能够充分利用子系统的试验数据来推导系统可靠性鉴定试验的方案，在风险可控的条件下缩短试验时间，从而缩短产品的研制周期。项目研究提出的方法不仅可以应用于航天产品研制阶段的可靠性评估与鉴定工作，而且可以推广应用于其他领域复杂产品的可靠性评估与鉴定。项目组已在某型雷达、电子干扰设备的可靠性鉴定中开展了应用。