System optimization of steam generation in the dual-flash compound circulation system

Abstract

Concentrating on the problem of massive energy loss in the compressor, expansion valve, and the other components present in the high-temperature heat pump system under extensive temperature lift, the dual-flash compound circulation system is proposed and the thermodynamic model of the dual-flash compound circulation system was established. The article combines the multivariate simulated annealing algorithm, utilizes the system COP as the optimization goal, and completes the calculation of the thermodynamic parameters in the steady-state of the system that is based on satisfying the conditions of the system process. Using R245fa as the refrigerant, the condensation temperature is set within the range of 110°C–140°C for the model calculation. The results show that, compared to the traditional two-stage compression system under the same environment, the COP of the dual-flash compound circulation system can be increased up to 5.71%–12.13%, and the exergy efficiency can be increased by 5.11%–10.71%, respectively. Besides, steam production per unit refrigerant is also increased by 3.79%–5.14%. Finally, the feasibility of the theoretical model is verified by simulation, and it is concluded that the dual-flash compound circulation system has better steam production performance at the extensive temperature lift and the elevated condensation temperature.

Research on multi-objective parameter optimization of split flow dual flash thermodynamic cycle

“…The results show that compared with traditional single stage compression systems, the thermal performance of systems with steam replenishment characteristics has improved by 4% to 6%. Zhang et al [4] [5] analyzed the reuse of low-temperature heat energy in large-span high-temperature heat pump systems using energy efficiency analysis methods. The results show that compared with traditional heat pumps, the COP of the dual flash heating system has increased by 23.8% to 44.54%.…”