This paper proposed a heat-driven thermoacoustic heat pump system capable of utilizing medium/low-grade heat for heating supply in domestic applications. The system consists of one simple thermoacoustic energy-conversion unit with a direct-coupling configuration, which greatly reduces the system complexity compared to the traditional multi-stage thermoacoustic systems. The dimensional parameters of the system were optimized under nominal conditions, with heat-sink and heat-source temperatures of 55 Â°C and 7 Â°C. Simulation results show that the proposed system can obtain a heating capacity of 5.7 kW and an overall coefficient of performance of 1.40 at nominal conditions. Economic performance shows annual fuel energy savings and energy cost savings for individual systems are 20.3 MWh/year and 675 $/year. The environmental assessments show that the proposed system can displace CO2 emissions amounting to 3.72 tCO2/year. Exergy loss of each component was then given better to understand the energy conversion processes of the system. Moreover, system performance under different heat-source and heat-sink temperatures was studied.
Keywords Thermoacoustic heat pump; Building energy; Low/medium-grade heat recovery; Domestic heating; Energy saving; Energy conversion technology.