4E analyses of a novel solar-assisted vapor injection autocascade high-temperature heat pump based on genetic algorithm

Abstract

Insufficient heating performance is one of the main obstacles that inhibit the widespread application of autocascade heat pump. Therefore, a novel solar-assisted vapor injection autocascade high-temperature heat pump is put forward, which owns two working modes to take full use of solar energy and air energy. At first, the performance variations of the novel system with key operating parameters are theoretically investigated to assess the system characteristics. Thereinto, under considered condition, SV mode is more appropriate to the novel system than VA mode under over 200 W m−2 solar radiation intensity. And then, the energy, exergy, economic and environmental performance of the novel system, vapor injection autocascade heat pump and convenient autocascade heat pump is conducted based on genetic algorithm. The novel system respectively increases the maximum heating COP and corresponding heating capacity by averages of 16.5 % and 18.1 %, in comparison with the vapor injection autocascade heat pump. The irreversibility distributions in three systems are also analyzed. Moreover, the novel system produces the lowest full life cycle cost and air pollutant emissions among three systems. Under given application scenario, the payback period is 2.06 years and 2.95 years when the novel system is adopted to replace other two systems.