Cooling system of slow-speed marine propulsion diesel engine

U završnom radu opisan je centralni sustav hlađenja brodskog sporohodnog dvotaktnog dizel motora MAN B&W 7L70ME-C. Izgaranjem goriva u cilindrima motora postižu se visoke temperature pa zbog toga treba hladiti cilindarske košuljice motora, glave motora, stapove motora, rasprskače goriva, sjedišta i kućišta ispušnih ventila te turbopuhalo. Opisano je hlađenje visoko temperaturne rashladne vode, sistemskog ulja i ispirnog zraka u rashladnicima, uključujući izračun odvedenih toplina u rashladniku rashladne vode cilindarskih košuljica motora, sistemskog ulja i ispirnog zraka, te je napravljen izračun protočne mase rashladne vode niske temperature kroz rashladnik sistemskog ulja i rashladnik ispirnog zraka. Napravljen je izračun odvedene topline u centralnom rashladniku. Odvedena toplina u centralnom rashladniku ovisna je o odvedenim toplinama u rashladnicima rashladne vode cilindarskih košuljica motora, sistemskog ulje i ispirnog zraka. Izračun je napravljen za motor MAN B&W 7L70ME-C pri MCR-u.In this final paper, a central water cooling system of a ship is low speed two stroke diesel engine MAN B&W 7L70ME-C is described. By fuel combustion in the engine cylinders, high temperatures are achieved so we need to cool the cylinder liners, cylinder heads, pistons, fuel injectors, exhaust valve seats and casing and the turbocharger. The paper contains a description of cooling high temperature water, system oil and scavenging air cooling in the coolers, including the calculation of heat taken away from the cylinder liners coolers, system oil and the scavenging air. Also, a calculation of low temperature cooling water mass flow rate through the system oil and the scavenging air coolers has been made. The calculation of heat taken has been made for central cooler. The heat taken from central cooler depends of taken heats from cylinder liner cooling water, the system oil and the scavenging air coolers. The heat taken away in the central cooler depends on the heat taken away in the cylinder liners cooling water coolers, system oil and scavenging air. The calculation was made for the MAN B&W 7L70ME-C at MCR