MEDIUM SIZE LNG TANKER LUBRICATING SYSTEM HEAT EXCHANGER (COOLER) ANALYSIS

Abstract

As part of the project, the necessary steps are taken to carry out a calculation of a main engine lubrication system fitted on board an LNG tank vessel with a capacity of 45,000 dwt. The validation of the system is achieved by using a calculation program based on finite element theory (CFD). This is a new ship with a series of innovations regarding the construction of the cargo tanks, which was built in 2018. For sure, this engine is a dual fuel type, powered by marine fuel and natural gas. A general description of the naval lubrication system is made, then a specific calculation is performed for the essentials, such as: the main oil pump, the oil storage tanks, the oil separator, the oil filters and the oil cooler. Next, the focus is on the oil cooler, which is considered an essential part of the installation. In the first part of chapter five it is described in detail, from a constructive and functional point of view, then, using the Ansys program, the corresponding calculation is performed to verify it. A model is made according to the geometrical characteristics, then a series of specific simulations are performed. The main purpose of the simulation is to determine de operational behaviour of this heat exchanger from a temperature point of view and to establish its optimal operational status. This cand be done by establishing a proper simulation model and by conducting a precise simulation stage focused and key parameters. As noted in the final part of this study the temperature contour in the heat exchanger for cooled oil flows form minimum 291 0K to maximum 363 0K, this being its optima operational limit.