Internal combustion engine-based poly-generation systems have been widely used for energy savings and emissions reductions.To maximize their thermodynamic and environmental performance potentials,the efficient recovery of flue gas and jacket water heat is essential.In a conventional internal combustion engine-based steam and power cogeneration system,the low-temperature (less than 170℃) heat from flue gas and jacket water is usually directly discharged to the environment,which dramatically reduces the thermal and economic performance.In this work,a high-temperature heat pump is employed to recover this part of low-temperature heat for steam generation.The sensible heat of the flue gas and jacket water is cascade utilized in a steam generator and a heat pump.Simulation results show that the process steam yield of the proposed system is almost doubled (increased by 703 kg/h) compared to that of an engine-based cogeneration system without a heat pump.The proposed system can reduce natural gas consumption,CO2 and NOx emissions by approximately 199 069 m3,372.64 tons and 3.02 tons per year,respectively,with a primary energy ratio and exergy efficiency of 72.52％ and 46.28％,respectively.Moreover,the proposed system has a lower payback period with a value of 5.11 years,and the determining factors that affect the payback period are natural gas and electricity prices.The total net present value of the proposed system within its lifespan is 2 441 581 USD,and an extra profit of 785 748 USD can be obtained compared to the reference system.This is a promising approach for replacing gas boilers for process steam production in industrial sectors.