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A British-Chinese research group designed a dual-source heat pump (DSHP) that recovers waste heat from exhaust air along with absorbing heat from outdoor air.
An international research team has developed a Dual Source Heat Pump (DSHP) heating system designed for applications with high leaving water temperature and low ambient temperature.
“We have manufactured several prototypes of the dual-source heat pump,” the lead author of the research, Jing Li, explained to pv magazine . “The technology has been applied in some public buildings, as well as in a residential house. We have also filed patent applications [in] the EU, the US and China.”
The prototype is based on two low-pressure (LE) evaporators, one medium-pressure (ME) evaporator, an economizer, a plate condenser, a vapor injection compressor, expansion valves, and five air fans. Two of the fans are exhaust air devices and are positioned at the top of the DSHP, while the other three fans are exhaust air devices and are deployed at the bottom.
Este sistema recupera el calor residual del aire de escape junto con la absorción del calor del aire exterior. Su configuración permite que el aire exterior fluya hacia la unidad exterior y se mezcle con el aire de escape enfriado, convirtiéndose así en un aire mezclado más caliente, que luego fluye a través de los evaporadores de baja presión para la segunda etapa de intercambio de calor. El aire mezclado libera a su vez toda la energía calorífica en el refrigerante de baja presión y se convierte en aire de descarga más frío que el ambiente exterior.
El compresor de inyección de vapor comprime el refrigerante evaporado de los evaporadores de baja presión y lo mezcla con el refrigerante de media presión. La mezcla resultante de refrigerante más frío se descarga en el condensador de placas, donde la propia mezcla libera energía calorífica al agua.
“Subsequently, a part of the refrigerant flows to the medium-pressure evaporator and the economizer for medium-pressure evaporation after the corresponding throttling,” the scientists explained, noting that their refrigerant is R410A and that the optimal refrigerant charge is 13 kg. . "The remainder [of the] refrigerant flows through the economizer for subcooling followed by low-pressure evaporation in low-pressure evaporators, thus completing a cycle."
The research group tested the systems performance on the roof of the Hull University Central Library in the UK, where it was connected to the black exhaust air duct. “The practical DSHP draws exhaust air through the duct from the office corner window to the top of the DSHP, and then produces hot water and stores it in water tanks by absorbing heat from the exhaust air and from the air. outside," it said.
The researchers found that the simulated DSHP system was capable of providing an average working water outlet temperature of 56.28 C and a stable monthly simulated Coefficient of Performance (COP) between 2.69 and 3.03 throughout the year. "The amount of simulated heating of the DSHP heating system was 9.85% higher than the practical result, while the simulated energy consumption was 6.36% lower than the practical result", they pointed out, referring to the differences they recorded between the simulated and the practical system.
Their analysis also demonstrated that, depending on the location, the proposed heat pump system is capable of achieving annual heating bill savings ranging from 20.64% to 54.36% and annual carbon reductions ranging from from 14.39% to 86.09%, compared to traditional gas boiler heating systems.
The system is presented in the article “ Eco-economic performance and application potential of a novel dual-source heat pump heating system”, published in Energy . The research group is made up of academics from Britains University of Hull and the University of Science and Technology of China. |
