| Summary: | This paper presents the results of a numerical study on the parameters that affect the efficiency of the cogeneration cycle of a ship’s power plant. The efficiency was assessed based on the excess power (N<sub>gen.</sub>) of a free turbine, operated with the inflow of gaseous nitrogen, which was used to generate electricity. A mathematical model and simulation of the regenerative cycle were created and adjusted to operate with a dual-fuel (diesel-liquid natural gas (LNG)) six-cylinder four-stroke engine, where the energy of the exhaust gas was converted into mechanical work of the regenerative cycle turbine. The most significant factors for N<sub>gen</sub>. were identified by parametrical analysis of the cogeneration cycle: in the presence of an ‘external’ unlimited cold potential of the LNG, N<sub>gen.</sub> determines an exhaust gas temperature Te<sub>g</sub> of power plant; the pressure of the turbo unit and nitrogen flow are directly proportional to N<sub>gen</sub>. When selecting the technological units for cycle realization, it is rational to use high flow and average <inline-formula><math display="inline"><semantics><mrow><msub><mi>π</mi><mi>T</mi></msub></mrow></semantics></math></inline-formula> pressure (~3.0–3.5 units) turbo unit with a high adiabatic efficiency turbine. The effect of the selected heat exchangers with an efficiency of 0.9–1.0 on N<sub>gen.</sub> did not exceed 10%. With LNG for ‘internal’ use in a ship as a fuel, the lowest possible temperature of N<sub>2</sub> is necessary, because each 10 K increment in N<sub>2</sub> entering the compressor decreases N<sub>gen.</sub> by 5–8 kW, i.e., 5–6%.
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