Evaluation of Steam Ejector Refrigeration and Heat Pump System on Marine Gas Turbine-Powered Naval Surface Ships

Naval surface ships are generally propelled by diesel engines and/or gas turbines. The waste gas from the gas turbines is released into the atmosphere at high temperatures and with high energy. Using this energy to cool and heat the naval surface ship will provide energy efficiency and reduce emissions. In this study, the cooling and heating needs of a naval surface ship will be met using exhaust gas from the gas turbine outlet, with an LM2500 gas turbine drive and a steam ejector cooling and heating system. In a study of two ship types (corvette and frigate), the required steam flow rates, heating loads, heating–cooling COPs, saved fuel rate, saved fuel cost, and reduced CO2 emissions for the required cooling capacities have been calculated. For a corvette with a cooling capacity of 540 kW, it saved 830.68 USD/h in cost and reduced CO2 emissions up to 2123.61 kg/h, given a steam inlet pressure of 9.5 bar, evaporation pressure of 0.8 kPa, and a 1/ω (inverse of the entrainment ratio) of 5. For the frigate with a cooling capacity of 720 kW, it saved up to 1107.58 USD/h in cost and reduced CO2 emissions by up to 2831.48 kg/h, given a steam inlet pressure of 9.5 bar, evaporation pressure of 0.8 kPa, and a 1/ω of 5.