Working domains of a hybrid absorption-compression heat pump for industrial applications

Abstract

Absorption-compression heat pumps are especially suitable for high-temperature heat production, however, its performance at different conditions are highly influenced by the choice of ammonia-rich solution mass fraction and circulation ratio. This paper revealed the working domains of a hybrid absorption-compression heat pump for high-temperature (>130 °C) saturated steam production and obtained its optimized thermodynamic performance at different conditions. For saturated steam production, a supplied heat temperature up to 160 °C can be obtained using commercially available components with a thermal benefit compared to a gas boiler. For hot water or air production, the supplied temperature can be even higher. Moreover, a new heat coefficient of performance is proposed to evaluate the heat pump systems with both heat and power consumption. There are optimal heat coefficient of performance values for the circulation ratio and ammonia-rich solution mass fraction for the hybrid system. The results indicated that setting the ammonia-rich solution mass fraction less than 0.6 and the circulation ratio more than 0.7 is a better choice for the hybrid system in actual application. Finally, the hybrid heat pump system was used to improve the thermal performance of a saturated steam and power cogeneration system driven by an internal combustion engine. This work provides a useful guidance for the hybrid absorption-compression heat pump in actual application.