ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ МАЛООБЕРТОВОГО ДВИГУНА ЕЖЕКТОРНОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ ПРИ ЕКСПЛУАТАЦІЇ СУДНА В ТРОПІЧНИХ УМОВАХ

Abstract

The efficiency of air cooling at the inlet of the main low-speed engine turbocharger of a transport vessel during operation in tropical climatic conditions on the Shanghai-Singapore-Shanghai route was analyzed. A feature of the tropical climate is the high relative humidity, respectively, moisture content at its simultaneously high temperatures. The cooling of the air at the inlet of a low-speed engine with an ejector chiller by transforming the waste heat of exhaust gases into cold was studied. The ejector chiller is used as the most simple and reliable in operation. However, the efficiency of the transformation of heat into cold by ejector chillers is low - low thermal coefficients.A design solution of the system for cooling air at the inlet of the ship's main engine using the heat of the exhaust gases by an ejector chiller is proposed and analyzed. The effect of using the heat of the exhaust gases to cool the air at the engine inlet is analyzed taking into account the variable climatic conditions during the voyage of the vessel. It is shown that because of the insufficiently high efficiency of transforming the waste heat of the exhaust gases by an ejector chiller (low thermal coefficients), the obtained cooling capacity is not sufficient for cooling the air at the inlet of the turbocompressor during operation of a marine engine in tropical climatic conditions. Therefore, the possibility of use in the ejector chiller of additional heat of charge air, which is removed by cooling water, is also considered. It is shown that the use of the heat of exhaust gases and charge air for cooling the air at the engine inlet in an ejector chiller makes it possible to double decrease the air temperature at the inlet of the main engine by 20-30 °C when the vessel operates in tropical climatic conditions on a voyage lines Shanghai-Singapore-Shanghai. This, in turn, provides an almost twice fuel consumption reduction in compared with its reduction in the case when the ejector chiller uses only the heat of the exhaust gases.