Experimental analysis of a direct expansion solar assisted heat pump with integral storage tank for domestic water heating under zero solar radiation conditions

Fernández-Seara, José; Piñeiro, Carolina; Dopazo, Joaquín; Fernandes, F. T.; Sousa, Paulo X.B.

doi:10.1016/j.enconman.2012.01.018

Cited by 74 publications

(24 citation statements)

References 15 publications

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“…Thirdly, there have been many successful applications of DVG technology using refrigerant. One application is the solar assisted heat pump (SAHP) systems [23][24][25][26]. CPC, FPC and evacuated heat pipe collectors can be employed.…”

Section: Introductionmentioning

confidence: 99%

Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

Alvi

Pei

et al. 2016

Applied Thermal Engineering

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A novel solar organic Rankine cycle (ORC) system with direct vapor generation (DVG) is proposed. A heat storage unit is embedded in the ORC to guarantee the stability of power generation. Compared with conventional solar ORCs, the proposed system avoids the secondary heat transfer intermediate and shows good reaction to the fluctuation of solar radiation. The technical feasibility of the system is discussed. Performance is analyzed by using 17 dry and isentropic working fluids. Fluid effects on the efficiencies of ORC, collectors and the whole system are studied. The results indicate that the collector efficiency generally decreases while the ORC and system efficiencies increase with the increment in fluid critical temperature. At evaporation temperature of 120 o C and solar radiation of 800 Wm-2 , the ORC, collector and overall thermal efficiencies of R236fa are 10.59, 56.14 and 5.08% while their values for Benzene are 12.5, 52.58 and 6.57 % respectively. The difference between collector efficiencies using R236fa and Benzene gets larger at lower solar radiation. The heat collection is strongly

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Section: Introductionmentioning

confidence: 99%

Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

Alvi

Pei

et al. 2016

Applied Thermal Engineering

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“…Fernández-Seara et al [37] presented an experimental evaluation of a direct SAHP system during no solar radiation conditions. The system also used the storage tank as the condenser.…”

Section: Studiesmentioning

confidence: 99%

“…Each test continued until the water temperature reached 55℃. It was found that as the ambient temperature increased, the time required for heating decreased and the COP of the heat pump and of the system increased [37].…”

Section: Studiesmentioning

confidence: 99%

Evaluation of a Dual Tank Indirect Solar-Assisted Heat Pump System for a High Performance House

Chu¹

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This work focused on the design and evaluation of an integrated mechanical system, which incorporated a dual tank indirect solar-assisted heat pump, that offsets spaceheating, cooling, and domestic hot water loads for a high performance house. A model of the system was developed to investigate the effects of various parameters on the performance of the system. These parameters included the tank configurations, the solar collector size and orientation, and heat pump size and controls. In addition, an experimental study was conducted to investigate the relationship between the heat pump load side flow rate, the heat pump performance, and the thermal stratification in the storage tank. The experimental results indicated that the coefficient of performance of the heat pump reduced with lower flow rates. However, lower flow rates could result in higher temperature rises across the condenser and greater levels of the stratification which could improve the overall performance of the system by reducing the auxiliary energy consumption. Results from the modelling and experimental work were compared and the experimental results were used to improve the heat pump performance map that was used in the simulations. The simulation results showed that the system could achieve a free energy fraction of 0.506 (neglecting energy draws from circulation pumps and fans) for space-heating, cooling, and domestic hot water. This result suggests that the system does have the potential of reducing energy consumption in the residential sector in Canada. iii Table of Contents iv List of Tables viii List of Figures x Nomenclature xiv u COP Uncertainty of the coefficient of performance u COPaverage Uncertainty of the average coefficient of performance u Q load Uncertainty of the accumulated energy transferred (kJ) u Pcomp Uncertainty of the accumulated heat pump energy consumption (kJ) uṖ comp Uncertainty of the heat pump power consumption (kW) uQ load Uncertainty of the heat pump heat transfer rate (kW)

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“…They proved the roll-bond panel with optimized channel pattern could improve the performance of the DX-SAHP system significantly. The performance of a DX-SAHP water heater with integral storage tank with solar irradiance of zero was experimentally investigated [18]. The solar collectors were installed in a climate chamber to work at stable ambient air temperature.…”

Section: Introductionmentioning

confidence: 99%

Effects of Ambient Parameters on the Performance of a Direct-Expansion Solar-Assisted Heat Pump with Bare Plate Evaporators for Space Heating

Huang¹,

Ji²,

Modjinou³

et al. 2017

International Journal of Photoenergy

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Research on the direct-expansion solar-assisted heat pump (DX-SAHP) system with bare plate evaporators for space heating is meaningful but insufficient. In this paper, experiments on a DX-SAHP system applying bare plate evaporators for space heating are conducted in the enthalpy difference lab with a solar simulator, with the ambient conditions stable. The independent effects of ambient temperature, solar irradiation, and relative humidity on the system performance are investigated. When ambient temperature changes as 5°C, 10°C, and 15°C, COP increases as 2.12, 2.18, and 2.26. When solar irradiance changes as 0 W m−2, 100 W m−2, 200 W m−2, 300 W m−2, and 500 W m−2, COP of the system changes as 2.07, 2.09, 2.14, 2.26, and 2.36. With ambient temperature of 5°C and solar irradiance of 0 W m−2, when relative humidity is 50%, no frost formed. Whereas with relative humidity of 70% and 90%, frost formed but not seriously frosted after 120 min of operating. Frost did not deteriorate but improved the heating performance of the DX-SAHP system. The change of relative humidity from 70% to 90% improves the evaporating heat exchange rate by 35.0% and increases COP by 16.3%, from 1.78 to 2.07.

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Experimental analysis of a direct expansion solar assisted heat pump with integral storage tank for domestic water heating under zero solar radiation conditions

Cited by 74 publications

References 15 publications

Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

Effect of working fluids on the performance of a novel direct vapor generation solar organic Rankine cycle system

Evaluation of a Dual Tank Indirect Solar-Assisted Heat Pump System for a High Performance House

Effects of Ambient Parameters on the Performance of a Direct-Expansion Solar-Assisted Heat Pump with Bare Plate Evaporators for Space Heating

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