Development of a boost system turbocompaund piston engine

Abstract

The requirements for modern engines are constantly being tightened in terms of ensuring economic and environmental parameters. Thermodynamic analysis shows that approximately 30-40% of fuel energy is emitted into the environment by exhaust gases. For this reason, obtaining additional energy from exhaust gases is a promising way to significantly improve the thermal efficiency of the engine. Methods for generating additional energy from exhaust gases include: turbocharging, turbocompound, Brighton cycle, Rankine cycle and thermoelectric generators. These methods showed an increase in thermal efficiency, which vary from 2-20%, depending on the design of the system, the quality of energy recovery, component efficiency and implementation. In this work theme of one of the promising options for energy saving in piston engines will be revealed. Unfortunately, the topic turbocompounding in Russia is poorly studied, there are no methods for developing these systems, recommendations for selecting boost units. The aim of this work is to create a turbocompound system for boosting an aircraft engine. In accordance with the goal, the following tasks are formulated and solved: studied domestic and international experience in creating turbocharging systems for turbocharged piston engines; a methodology has been developed for creating turbocharged boost systems for internal combustion engines; recommendations were developed to coordinate the joint operation of a turbocompressor and a power turbine, as well as a turbocompound system with an engine; developed recommendations for choosing a method for regulating turbocompound boost systems. Based on the developed methodology and recommendations, the calculation of the pressurization parameters of the APD - 500 diesel aircraft piston engine with a power of 368 kW was performed. The required characteristics of the blade machines were determined and the required sizes were selected. The choice of turbochargher was made by superimposing the flow characteristics of the APD-500 engine on the characteristics of the compressor stage of the turbochargher. The parameters of the power turbine were calculated, the required gear ratio of the power turbine gearbox was determined.