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ALCO251柴油机是一种广泛应用于铁路牵引、船舶推进和辅助机组、发电站等领域的中速四冲程柴油机。本文着重进行了用于核电站备用发电机组的ALCO251柴油机气缸套裂纹的原因分析。分析结果确认了引起气缸套凸缘裂纹的各种条件。业已证明，虽然高循环疲劳会引起气缸套凸缘裂纹，但大多数裂纹将停止扩展。带有这种已停止扩展的裂纹的气缸套预期可继续提供可靠的运行。在最坏的情况下，低循环热疲劳有可能引起裂纹扩展，直至超过标准临界点，最终导致气缸套凸缘严重损坏。提出了预防换装的气缸套再发生裂纹的若干措施。这些措施适用于所有ALCO251柴油机的用户。气缸套裂纹原因的研究分析包括有限元应力分析、气缸套的断裂力学分析和用于其它领域的ALCO251柴油机应用经验的详细考察。文中对所有这些分析和研究的结果都一一作了介绍。
ALCO251 diesel engine is a medium-speed four-stroke diesel engine widely used in the fields of railway traction, ship propulsion and auxiliary units, power stations and other fields. This article focuses on the reasons for the crack of ALCO251 diesel engine cylinder liner used in the standby power plant of nuclear power station. The results of the analysis confirmed various conditions that led to the cracking of the liner flange. It has been demonstrated that while high cycle fatigue can cause cylinder liner flange cracking, most cracks will stop expanding. Cylinder liners with this cracked extension have been expected to continue to provide reliable operation. In the worst case, low cycle thermal fatigue may cause crack propagation until it exceeds the standard critical point, eventually causing serious damage to the flange of the liner. A number of measures have been put forward to prevent the cylinder liner from reloading from cracking. These measures apply to all ALCO251 diesel users. The research and analysis of the causes of cylinder liner cracks include the finite element stress analysis, fracture mechanics analysis of cylinder liner and the application of ALCO251 diesel engine in other fields. All the results of these analyzes and studies are introduced in this paper.