Exergy analysis of a photovoltaic thermal system with earth water heat exchanger cooling system based on experimental data

Solar energy is typically collected through photovoltaic (PV) to generate electricity or through thermal collectors as heat energy, they are generally utilised separately. This project is done with the purpose of integrating the two systems to improve the energy efficiency. The idea of this photovoltaic-thermal (PVT) setup design is to simultaneously cool the PV panel so it can operate at a lower temperature thus higher electrical efficiency and also store the thermal energy. The experimental data shows that the PVT setup increased the electrical efficiency of the standard PV setup from 1.64% to 2.15%. The integration of the thermal collector also allowed 37.25% of solar energy to be stored as thermal energy. The standard PV setup harnessed only 1.64% of the solar energy, whereas the PVT setup achieved 39.4%. Different flowrates were tested to determine its effects on the PVT setup’s electrical and thermal efficiency. The various flowrate does not significantly impact the electrical efficiency since it did not significantly impact the cooling of the panel. The various flowrates resulted in fluctuating thermal efficiencies, the relation between the two is inconclusive in this project.

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Performance Study of an Oil-Immersed Power Transformer With Shallow Geothermal Cooling

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4031889 ◽

2015 ◽

Vol 8 (2) ◽

Cited By ~ 2

Author(s):

Gerd Schmid ◽

Chien-Yeh Hsu ◽

Yu-Ting Chen ◽

Tai-Her Yang ◽

Sih-Li Chen

Keyword(s):

Experimental Data ◽

Thermal Analysis ◽

Heat Exchanger ◽

Water Flow ◽

Cooling System ◽

Flow Direction ◽

Water Flow Rate ◽

Transformer Oil ◽

Performance Study ◽

Cooling Performance

This paper investigates the cooling performance of a shallow geothermal energy method in relation to the cooling system of a 75 kVA oil-immersed transformer. A thermal analysis of the complete system is presented and then validated with experimental data. The cooling performance of the shallow geothermal cooling method is indicated by its cooling capacity and average oil temperature. The results of this study show that the average oil temperature can be reduced by nearly 30 °C with the aid of an 8 m deep U-pipe borehole heat exchanger, thereby making it possible to increase the capacity of the transformer. By increasing the water flow rate from 6 L/m to 15 L/m, the average oil temperature could be lowered by 3 °C. In addition, the effects of changing the circulating water flow direction and the activation time of the shallow geothermal cooling system were investigated. The results of the thermal analysis are consistent with the experimental data, with relative errors below 8%. The results of the study confirm that a larger temperature difference between the cooling water and the transformer oil at the inlet of the heat exchanger can increase the overall heat transfer rate and enhance the cooling performance of the shallow geothermal cooling system.

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Energy and exergy analysis of solar photovoltaic thermal system: experimental and numerical verification

International Journal of Exergy ◽

10.1504/ijex.2021.10034153 ◽

2021 ◽

Vol 34 (1) ◽

pp. 16

Author(s):

Metin Gül ◽

Ersin Akyüz

Keyword(s):

Exergy Analysis ◽

Thermal System ◽

Numerical Verification ◽

Solar Photovoltaic ◽

Photovoltaic Thermal System ◽

Energy And Exergy ◽

Energy And Exergy Analysis

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Correlation Investigation of Condensation Heat Exchanger Design for Secondary Passive Cooling System

Volume 3: Thermal-Hydraulics; Turbines, Generators, and Auxiliaries ◽

10.1115/icone20-power2012-55101 ◽

2012 ◽

Author(s):

Hee Joon Lee ◽

Han-Ok Kang ◽

Tae-Ho Lee ◽

Cheon-Tae Park

Keyword(s):

Heat Transfer ◽

Experimental Data ◽

Heat Exchanger ◽

Cooling System ◽

Condensation Heat Transfer ◽

Passive Cooling ◽

Heat Transfer Correlation ◽

Data Set ◽

Heat Exchanger Design ◽

Passive Cooling System

Recently vertical or horizontal type condensation heat exchangers are being studied for the application to secondary passive cooling system of nuclear plants. To design vertical condensation heat exchanger in water pool, a thermal sizing program of condensation heat exchanger, TSCON (Thermal Sizing of CONdenser) was developed in KAERI (Korea Atomic Energy Research Institute). In this study, condensation heat transfer correlation of TSCON is evaluated with the existing experimental data set to design condensation heat exchanger without non-condensable gas (pure steam condensation). From the investigation of the existing condensation heat transfer correlation to the existing experimental data, the improved Shah correlation showed most satisfactory results for the heat transfer coefficient and mass flow rate in a heat exchanger in both subcooled and saturated water pools without the presence of non-condensable gas.

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