New test methodologies to analyse direct expansion solar assisted heat pumps for domestic hot water

Facão, Jorge; Carvalho, María Miguel

doi:10.1016/j.solener.2013.11.025

Cited by 26 publications

(8 citation statements)

References 17 publications

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“…The superheating vapour (2) is cooled in the flash tank by saturated liquid (7) up to saturated vapour (3). In the low-pressure cycle, the refrigerant is throttled in the expansion valve (7)(8) and feed the evaporator in the 8 state. For the high-pressure cycle, the saturated vapour is compressed by the high-pressure compressor (3-4) and then condensed in the condenser (4-5), and finally expands at the expansion valve (5-6).…”

Section: Direct Expansion Systemmentioning

confidence: 99%

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Review of the advances in solar-assisted air source heat pumps for the domestic sector

Yang

et al. 2021

Energy Conversion and Management

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Section: Direct Expansion Systemmentioning

confidence: 99%

“…Two approaches to solar boosting that have reported are direct expansion SAASHP (DX-SAASHP) [5][6][7][8][9] and indirect expansion SAASHP (IX-SAASHP) [10][11][12][13][14][15][16][17][18][19][20][21][22][23]. In the DX-SAASHPs, refrigerant is circulated directly through the solar collectors which serve as the HP evaporator.…”

mentioning

confidence: 99%

Review of the advances in solar-assisted air source heat pumps for the domestic sector

Yang

et al. 2021

Energy Conversion and Management

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“…Solar energy absorbed in the collector/evaporator is transferred to the load via the heat pump's condenser. The most common application for DX-SAHP is for water heating applications (Facao and Carvalho, 2014;Chaturvedi et al, 2014); in this case, the condensed working fluid exchanges heat with water in a thermal storage. The solar irradiance is changed with days and seasons, consequently the pressure and temperature of the evaporation vary.…”

Section: Direct Expansion Solar Assisted Heat Pumpmentioning

confidence: 99%

Combined building integrated photovoltaic-thermal collector with air source heat pump for cold climate

Kamel¹

2021

Preprint

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A TRNSYS model was developed to conduct a comprehensive study of combining a building integrated photovoltaic thermal (BIPV/T) collector with an air source heat pump (ASHP) in an Archetype Sustainable House. The heat pump uses the warm air generated in the BIPV/T as the source for heat production. The coupling of BIPV/T and ASHP enables a highly efficient heating system in winter conditions. A numerical model was developed for an air-based PV/T collector. The model was used to predict the thermal and electrical performance of the collector and to conduct a comprehensive analysis for different configurations (number of PV/T panels in rows NR and in series NS) and different design parameters. TRNSYS simulation results showed that low air mass flow rate and low duct depth enhance the heat pump coefficient of performance (COP). The arrangement with a large number of PV/T systems connected in series has higher COP. The maximum obtained seasonal heating COP was 3.45, corresponding to duct depth of 1.5 in, NS=5 and low row mass flow rate of 0.03 kg/s. The heat pump cumulative electricity consumption for a typical heating season could be reduced by 20.2%. When the analysis was based only on sunny hours, the electricity consumption of the combined ASHP + PV/T system was reduced by 52% and the predicted seasonal COP of the heat pump was 5.98. A new full-scale test facility was presented to be implemented at Toronto and Region Conservation Authority to examine the performance of combining passive system and dynamic building envelope technologies (BIPV/T+ASHP+TES) under real weather conditions. It is important to match the maximum airflow for the BIPV/T system with the maximum airflow for the outdoor coil of the heat pump. The pressure drop inside the PV/T collector along with the connecting air duct from the BIPV/T to ASHP for a wide range of airflow rates and different duct depths was calculated. It was found that for air a flow rate around 2000 CFM, which is the maximum CFM for the custom-made ASHP for the test facility, the predicted fan energy was 195 kWh/year corresponding to 1.5 in. duct depth.

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“…Other researchers have worked on serial systems in which heat pump evaporator consists in a solar collector. The refrigerant circulates directly in the solar collector [13,14]. There are also indirect systems in which the heat pump and the solar collector are linked with a heat exchanger.…”

Section: Solar Collectors and Heatmentioning

confidence: 99%

Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

Semenou

Rousse

Lostec

et al. 2015

Mathematical Problems in Engineering

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Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC) with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC). The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20 ∘ K when the solar irradiation is high.

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New test methodologies to analyse direct expansion solar assisted heat pumps for domestic hot water

Cited by 26 publications

References 17 publications

Review of the advances in solar-assisted air source heat pumps for the domestic sector

Review of the advances in solar-assisted air source heat pumps for the domestic sector

Combined building integrated photovoltaic-thermal collector with air source heat pump for cold climate

Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector

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