Application and analysis of two-stage heat recovery and flash vaporization process in high-temperature heat pump systems for steam production.

In conventional high-temperature heat pump systems for steam production, large temperature and pressure differences between the heat source and heat production cause significant energy losses in compression and expansion process. This research integrates two-stage heat recovery and flash vaporization processes into the two-stage compression heat pump system to enhance its thermodynamic performance. The thermodynamic model of the system was optimized using a simulated annealing algorithm, and experimental validation was conducted. Results indicate that when the evaporation temperature is 50 ◦C and the condensation temperature ranges from 110 ◦C to 135 ◦C, the proposed system’s COP is 3.6–5.2, and its thermodynamic perfection degree is 0.75–0.81, 32.5–62.4 % higher than the conventional cascade system.