Working Process Control in a Ship Gas Turbine Engine of Complex Cycle

Abstract

Gas turbine engines (GTE) of complex cycles are more efficient in comparison to GTE of simple cycle, and they can be recommended for application in a ship propulsion complex. GTE’s representative of complex cycle is GTE with overexpansion turbine and heat regeneration, which has high efficiency, and which can provide heat energy to the consumers of specialized ships in co-generative mode of operation. GTE with R and OT is adapted for used in different conditions of ships’ operation. It has high power efficiency at partial loads due to the working process control in the engine. There are two applicable methods of getting required engine’s characteristics of GTE with heat regeneration at partial loads. If more constant production of heat energy is required at partial loads of the main engine, the method of air by-pass to the combustion chamber by recuperator is applied. Hereby, utilized heat is being redistributed towards the gas cooler boiler-utilizer increasing its power. For the increase of efficiency of GTE with R and OT at partial loads it is used the method of GTE’s characteristics change by application of variable area nozzles (VAN) of power turbine. VAN in GTE with R allows keeping initial temperature of gas in the engine close to nominal value at partial loads. If the efficiency of GTE with R and OT at nominal load is 20 % relatively higher, in this case when power is equal to 50%, the efficiency of GTE with R and OT is 30% higher in relation to Brayton cycle. In GTE with R and OT it is possible to apply two methods of working process control simultaneously in various regimes of ship operation.