Monitoring the locomotive diesel cylinder-piston group technical condition during the pre-start cold cranking

Abstract

High-speed diesel engines of small dimensions (with the cylinder diameter of up to 210 mm) are increasingly used as prime movers in the autonomous locomotives of various purposes. Characteristic design feature of many of them lies in the absence of indicator valves to connect devices measuring the intra-cylinder pressure (maximum meter or pressure sensor). It excludes the possibility of using diagnostic methods based on the indicator analysis to control technical state of the cylinder-piston group of such engines based on analyzing diagrams of the working process inside the cylinder. This circumstance determines relevance of searching for other approaches to solve this problem. One of such approaches is based on monitoring parameters of the signal of the crankshaft instantaneous angular velocity and the starter motor current in the engine cold cranking mode. Based on analyzing alteration in the crankshaft instantaneous angular speed and the starter motor current in the cold cranking mode during bench testing of the locomotive diesel, diagnostic parameters, indicators and criteria to monitor the diesel cylinders performance were proposed. Effectiveness of the proposed criteria was confirmed by analysis of the results of the diesel engine cold scrolling with the opened indicator cocks of individual cylinders. Using the proposed diagnostic criteria would improve operational reliability and reduce cost of the diesel locomotive maintenance through rational planning the scope of work within the scheduled repair operations.