The Choice of Cooling Parameters for Marine Diesel Engines

Abstract

The main trend in the development of modern engine building is the acceleration of internal combustion engines at an average effective pressure and boost pressure. This leads to an increase in thermal and mechanical loads on the main parts of the engine, the increase in vibration of diesel engines, which necessitates the improvement of systems that ensure reliable operation of the engine in the entire range of operating conditions, especially lubrication and cooling systems. One of the factors negatively affecting the reliability of engines with liquid cooling systems are erosion and corrosion damage to the elements of the systems, especially the outer surfaces of the cylinder sleeves, washed by the coolant. The article is devoted to the actual problem-the choice of cooling parameters of modern internal combustion engines with a high level of acceleration and advanced engines. The method of choice of cooling parameters includes the identification of the most important of them and the reasonable determination of the preferred values of these parameters, taking into account the requirements of efficiency and reliability of marine diesel engines. To solve this problem, an algorithm is proposed that takes into account the design characteristics of the engine, the parameters of the workflow, cooling modes. The article presents the calculation formulas that allow to implement the proposed algorithm. The temperature and pressure in the cooling system and the hydrogen index of the coolant are set as the main cooling parameters affecting the intensity of erosion-corrosion damage and the efficiency of the diesel engine. The results of the calculations allow to estimate the influence of these factors on the intensity of erosion-corrosion damage and specific fuel consumption, as well as to recommend the most preferred cooling parameters. The conclusions made on the basis of the calculations are confirmed by the results of motor tests. The article offers technical solutions that allow automatic control of cooling parameters of marine diesel engines.