The efficiency of cooling the scavenge air of the main low-speed engine of the transport vessel during operation in the equatorial tropical latitudes is analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures and temperatures of seawater. The cooling of the scavenge air with an absorption lithium bromide chiller by transforming the scavenge air heat into the cold was investigated. With this, the potentially possible minimum temperature of the cooled air was determined considering the temperature of the cold water (coolant) from the absorption lithium bromide chiller and the temperature differences in the heat exchangers of the intermediate water circuit of cooling. Absorption lithium bromide chillers are characterized by high efficiency of transformation of waste heat into cold - high coefficients of performance. Circuit-design solution of three-stage cooling system of scavenging air of ship's main engine - in high-temperature (cogeneration) stage using the extracted heat of scavenging air to get cold with absorption chiller and traditional stage for cooling scavenge air by seawater and low-temperature cooling stage by absorption chiller. The effect of deeper cooling of the scavenge air was determined in comparison with the cooling of the scavenge air with seawater, taking into account the changing climatic conditions during the route of the vessel. It is shown that due to the high efficiency of heat transformation in absorption chillers (high coefficients of performance 0.7…0.8), there is a significant amount of excess heat of scavenging air over the heat required to cool it to 22 °C, which reaches almost half of the available scavenge air heat on the Shanghai-Singapore-Shanghai route. This reveals the possibility of additional cooling the inlet of the turbocharger of the engine with the achieving almost double fuel economy due to the cooling of all cycle air of the low-speed engine, including the air at the inlet.

The efficiency of air cooling at the inlet of gas turbine engines by exhaust heat conversion chiller, which transforms the GTE exhaust gases heat into cold, under variable climatic operating conditions, has been investigated. Considered is the use of a combined absorption-ejector exhaust heat conversion chiller with a step-by-step principle of air cooling at the gas turbine engines inlet: preliminary down to 15°C – by an absorption lithium-bromide chiller (ACh), which is used as a high-temperature air cooling stage, and further cooling down to 10°C – by a refrigerant ejector chiller (ECh) as a low-temperature cooling stage. Reserves have been identified for reducing the design (installed) refrigeration capacity of chillers by accumulating excess cold at reduced current heat loads with its use at increased heat loads. In this case, the design (installed) refrigeration capacity of chillers was determined by two methods: the first – based on the close to the maximum reduction in annual fuel consumption, the second – according to the maximum rate of increase in the reduction in annual fuel consumption. A scheme of the air cooling system at the gas turbine engines inlet using the refrigeration capacity reserve of the ACh, which provides preliminary cooling of the ambient air at the gas turbine engines inlet, in the booster stage, using the ACh accumulated excess refrigeration capacity has been proposed. The ACh excess refrigerating capacity, which is formed at decreased heat loads on the air coolers at the gas turbine engines inlet, is accumulated in the cold accumulator and is used at increased heat loads. The simulation results show the advisability of using the air cooling system at the gas turbine engine inlet with using the ACh accumulated excess refrigeration capacity, which allows reducing the ACh design (installed) refrigeration capacity by approximately 40%.