Performance Analysis of a New Cascade Waste Heat Recovery System With a Wider Range of Applications

Abstract

This paper proposes a new cascade waste heat recovery system with low power consumption and the ability to recover waste heat in a wider temperature range, namely, the absorption–compression coupled heat pump system. Simulations were conducted to reveal the effects of generator inlet and outlet water temperatures, supply hot water inlet and outlet water temperatures, and intermediate temperature on system performance. The results demonstrate that the coefficient of performance and exergy efficiency of the new system increase with an increase in generator outlet water temperature. The coefficient of performance and exergy efficiency of the new system decrease with an increase in supply heating water outlet water temperature. The coefficient of performance of the new system decreases with an increase in supply heating water inlet water temperature, while the exergy efficiency increases with an increase in supply heating water inlet water temperature. As the intermediate temperature increases, the coefficient of performance of the new system shows an increasing trend, and the exergy efficiency shows a decreasing trend. In addition, compared to the single-effect absorption heat pump system, the new system can recover heat at lower heat source temperatures, and compared to the compression heat pump system, it can reduce electricity consumption.