Influence of wear of high-pressure fuel pump plunger pairs on the performance of marine diesel engines

Abstract

 An overview of the author's studies focused on increasing the durability of plunger pairs of high-pressure fuel pumps of marine diesel engines and the effect of their wear on engine performance is presented, made from 1990 to 2020. The factors affecting the resource indicators of the plunger pairs of high-pressure fuel pumps of marine low- and medium-speed engines have been clarified. Methods and possibilities for assessing wear indicators of fuel equipment are determined. A comparative analysis of the resource capabilities of plunger pairs, restored by various methods, and new pairs, manufactured by leading diesel-building companies, as well as an analysis of the effect of wear of plunger pairs of high-pressure fuel pumps on the performance of marine diesel engines is presented.It is shown that as the plunger pairs of high-pressure fuel pumps of marine medium- and low-speed diesel engines wear out, the cycle fuel supply decreases due to its leaks, while the temperature of the exhaust gases rises, which often leads to emergency situations. To increase the efficiency of operation and reliability of diesel engines, we have developed a promising hardening technology, which makes it possible to increase the wear resistance of the injection pump plunger pairs.It has been shown for the first time that high-pressure fuel pump plunger pairs, restored by applying wear-resistant chromium coatings, successfully compete with serial (uncoated plungers), and in the case of applying composite coatings (chromium + cermet), they provide significantly higher wear resistance. The dynamic hydraulic density of the steam and, accordingly, the cyclic fuel supply of plunger pairs with a wear-resistant plunger coating remains practically unchanged for a longer time (the period of stable dynamic hydraulic density is on average 2–3 times longer than for uncoated steam). The conditions of operation of precision parts of the fuel equipment of marine low and medium speed engines are described. The factors influencing the service life of the plunger pairs are given. Methods and possibilities for assessing the wear indicators of fuel equipment are determined.