Increasing energy efficiency of gas piston TPP through integrated use of thermal secondary energy resources

Abstract

Recently, the advantages and prospects to use piston gas internal combustion engines for the combined generation of electrical and thermal energy have become increasingly obvious. The range of single capacities of gas piston units (GPU) ranges from 0,1 MW to tens of MW, which makes them more attractive when designing various power facilities. Most brands of gas piston units can operate in co-generation mode, that is, as a combined heat and power plant that simultaneously generates electrical and thermal energy. The purpose of this study is to substantiate the possibility of integrated use of heat of the cooling systems of the gas piston engine of a thermal power plant (TPP). The studies conducted are carried out using well-known methods of thermodynamic calculation of the internal combustion engine cycle, of determination of the components of its thermal balance and thermal calculation of the equipment for utilization of secondary thermal energy resources. The results of the analysis of the heat losses of the GPU drive engine have showed that the total losses during its operation are about 11544,5 kW. Average potential heat losses with flue gases are 45,87 %, and low-potential heat losses with water in cooling systems and oil in lubrication systems are 53,14 %. A schematic diagram is proposed for the integrated utilization of thermal renewable energy resources (RES) at a gas piston thermal power plant. The main difference between the proposed scheme and the existing technical solutions is the utilization of the heat of the low-temperature charge air cooling system after the second section of the compressor and the heat of the engine lubrication system. An analysis of the expenditure part of the energy balance of the drive engine in case of the integrated use of thermal RES in the GPU cycle, has showed that the implementation of energy-saving measures will make it possible to usefully use up to 93,05 % of the supplied energy in the generation of electrical and thermal power.