A novel configuration of ejector refrigeration cycle coupled with organic Rankine cycle for transformer and space cooling applications

Abstract

Abstract To provide stable voltage at some nodes of electricity grid network, gas engines are used for generating and injecting electricity to those specific nodes. A transformer is also required for increasing the voltage from that generated by the gas engine to the voltage of grid network. This transformer warms up due to power losses and needs to be cooled. Thus an ejector refrigeration cycle (ERC) which uses a part of available exhaust gas heating power in its generator for free, is selected for providing the required cooling effect. Furthermore the excess heating power of engine exhaust gas is used in an Organic Rankine Cycle (ORC) to generate electricity for selling to the grid. The proposed ERC-ORC configuration is novel, as the generator of ERC uses the rejecting heating power of ORC condenser. Modeling and optimizing the proposed ERC-ORC configuration are performed here for four selected gas engines. For example, results for 1948 MW gas engine integrated with ERC-ORC show that the ejector refrigeration system provides 271.1 kW cooling capacity with 0.33 coefficient of performance (COP) which decreases the transformer oil temperature for 20.2 °C and increases the transformer capacity for about 20%. Furthermore, 225.6 kW power output by the ORC system with 26.2% thermal efficiency is also generated.