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South Korean scientists have built an air-source heat pump integrated with a photovoltaic thermal unit that can reportedly achieve a heating and cooling average coefficient of performance (COP) of 3.54 and 3.31, respectively.
Researchers from Pusan ??National University (South Korea) have designed an integrated system based on a photovoltaic-thermal (PVT) unit and an air source heat pump (ASHP) for implementation in buildings Zero Energy Consumption (ZEB) with limited space.
In these buildings, the sum total of annual energy consumption is approximately equal to the sum total of renewable energy produced on site. “Our system has been designed to meet the entire heating, cooling, domestic hot water and electricity demand of a ZEB,” corresponding author of the research, Sangmu Bae, told pv magazine .
The scientists explained that the proposed system configuration offers more advantages compared to integrated PVT geothermal heat pumps (GSHPs), which have so far had limited success in real applications in urban areas due to the complex installation process and high costs. initials.
The system consists of a PVT module, an ASHP, a heat storage tank with a volume of 0.3 m3, a fan coil unit (FCU), three circulation pumps and three-way valves.
The 1.012m × 1.972m PVT panel is based on 0.015m and 0.008m diameter main and capillary pipes, respectively, which the academics say are easy to fabricate and weld. “The tubes were fully clamped and fixed through the jig and aluminum plate, and the slot in the plate had clearances available to account for tube expansion,” they explained.
The module achieves electrical and thermal efficiencies of 59.7% and 16.1%, as well as heating and cooling capacities equal to 7.55 kW and 11.36 kW, respectively.
The Korean group evaluated the heating and cooling performance of the PVT-ASHP system in a small-scale office building located in Busan and compared it with that of a PVT-GSHP. "The model included a control room," explains the study. "The air conditioning surfaces of the office and the monitoring rooms were equal to 85.8 m2 and 22.1 m2, respectively."
During the testing period, the system achieved a thermal efficiency of 18.1% and a production of 37 kWh. It also achieved electrical efficiency of 11.4% on a winter day and 10.2% on a summer day. The electrical production was 8.84 kWh and 12.9 kWh, respectively.
“The electrical efficiency was lower than that of a representative winter day,” the scientists explain. “However, the PVT module was able to generate more electrical power due to the higher total solar radiation and longer hours of sunlight.”
The heat pump also achieved an average heating and cooling coefficient of performance (COP) of 3.54 and 3.31, respectively. The PVT module was able to improve heat pump performance by up to 52% compared to an ASHP system without PVT power.
The PVT module was able to offset approximately 18% and 27% of the total power consumption of the PVT-ASHP system during the winter and summer seasons, respectively.”
winter and summer, respectively”, say the scientists, who add that the proposed system is also 44% cheaper than a PVT-GSHP system. |
