IMPROVING THE HEAT BALANCE BY USING THE EXHAUST GASES FOR A TANKER SHIP

Abstract

Me ch anical Te s ting and Di agnosis IS S N 2247 – 9635, 2018 (VIII), Volume 2, pp. 11-14 IMPROVING THE HEAT BALANCE BY USING THE EXHAUST GASES FOR A TANKER SHIP Article DOI : https://doi.org/10.35219/mtd.2018.2.02 Catalin FAITAR1)*, Andra Teodora NEDELCU2), Mihail Lucian DUMITRACHE1) 1) Maritime Univers ity of Cons tanta, Faculty of Naval Electromechanics , 104 Mircea cel Batran, RO-900663, Cons tanta, Romania 2) Mircea cel Batran Naval Academy, Faculty of Navigation and Naval Trans port, 1 Fulgerului, RO-900218, Cons tanta, Romania * Corres ponding author: catalinfaitar@yahoo.ro ABSTRACT Exhaust gas energy recovery is more preferred than the energy contained in the cooling water. This is determined by the higher exhau st gas temperature, from 250 °C to 400 °C, for two-strok e engines and from 400 °C to 500 °C for four-strok e engines. Recovery is accomplished by means of a heat exchanger, called a heat recovery boiler or directly from the exhaust gas by the entrainment of a power turbine that drives an electric generator. Mitsubishi engines waste recovery systems consist of high-quality, highly efficient machinery that significantly increases ov erall vessel efficiency and it is an effective way to reduce th e EEDI (energy efficiency design index ). Very large crude carriers (VLCC) are among the biggest work ing freight vessels on the planet. With a capacity more than 250,000 dwt, these big ve ssels are equipped with two -strok e engines of high power. Keywor ds : heat, recovery, engine, boiler, parameters 1. INTRODUCTIO N The abs olute thermal balance is us ed when it comes to analyze the us e of thermal energy on a particular engine, while the s p ecific heat balance, as well as the relative thermal balance, are us ed both for analyzing the us e of thermal energy and for comparing, in terms of effective efficiency, one engine to another. The dis tribution of the heat flows for a particular operating regime of an engine is repres ented graphically in Fig. 1. This figure s hows the heat balance diagram in which the heat flows are divided into components corres ponding to the real s ituation. The los t heat flow, Qpd , is : Qpd =Qint ‐(Qu +Qpr +Qpg ) (1)