Thermoacoustic heat pump utilizing medium/low-grade heat sources for domestic building heating

•A heat-driven thermoacoustic heat pump is simulated based on time-domain model.•Minimalist system structure is applied with improved acoustic matching.•Heating power of 5.7 kW with COPh of 1.4 is obtained in typical heating condition.•The system shows promising prospect in the large temperature lift applications.•An individual heat pump system can reduce CO2 emissions by 4143 kg a year. Thermoacoustic heat pumps are a promising heating technology that utilizes medium/low-grade heat to reduce reliance on electricity. This study proposes a single direct-coupled configuration for a thermoacoustic heat pump, aimed at minimizing system complexity and making it suitable for domestic applications. Numerical investigations were conducted under typical household heating conditions, including performance analysis, exergy loss evaluation, and axial distribution of key parameters. Results show that the proposed thermoacoustic heat pump achieves a heating capacity of 5.7 kW and a coefficient of performance of 1.4, with a heating temperature of 300 °C and a heat-sink temperature of 55 °C. A comparison with existing absorption heat pumps reveals favorable adaptability for large temperature lift applications. A case study conducted in Finland over an annual cycle analyzes the economic and environmental performance of the system, identifying two distinct modes based on the driving heat source: medium temperature (≥250 °C) and low temperature (