Theoretical and experimental investigations of a two-phase thermosyphon solar water heater

Entropy generated by operation of a two-phase self-pumping solar water heater under Solar Rating and Certification Corporation rating conditions is computed numerically in a methodology based on an exergy cascade. An order of magnitude analysis shows that entropy generation is dominated by heat transfer across temperature differences. Conversion of radiant solar energy incident on the collector to thermal energy within the collector accounts for 87.1 percent of total entropy generation. Thermal losses are responsible for 9.9 percent of total entropy generation, and heat transfer across the condenser accounts for 2.4 percent of the total entropy generation. Mixing in the tempering valve is responsible for 0.7 percent of the total entropy generation. Approximately one half of the entropy generated by thermal losses is attributable to the self-pumping process. The procedure to determine total entropy generation can be used in a parametric study to evaluate the performance of two-phase hot water heating systems relative to other solar water heating options.

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Latent Heat Storage in a Two-Phase Thermosyphon Solar Water Heater

Journal of Solar Energy Engineering ◽

10.1115/1.2147588 ◽

2005 ◽

Vol 128 (1) ◽

pp. 69-76 ◽

Cited By ~ 32

Author(s):

Wen-Shing Lee ◽

Bo-Ren Chen ◽

Sih-Li Chen

Keyword(s):

Energy Storage ◽

Latent Heat ◽

Heat Storage ◽

Solar Water Heater ◽

Water Heater ◽

Two Phase ◽

Latent Heat Storage ◽

Solar Water ◽

Energy Storage Material ◽

Optimum Charge

This article experimentally studies the thermal performance of latent heat storage in a two-phase thermosyphon solar water heater, which utilizes the superior heat transfer characteristics of boiling and condensation, and eliminates drawbacks found in the conventional solar water heater. Experimental investigations are first conducted to study the thermal behavior of tricosane (paraffin wax 116), water, and sodium acetate (NaCH3COO∙3H2O) used as energy storage materials. The results indicate that tricosane provides many advantages to be the energy storage material in the latent heat storage system. This study also examines the functions of charge and discharge thermal behaviors in a two-phase thermosyphon solar water heater. The results show that the system gives optimum charge and discharge performance under 40% alcohol fill ratio and with tricosane used as the energy storage material, and displays an optimum charge efficiency of 73% and optimum discharge efficiency of 81%.

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Experimental investigation of a two-phase closed thermosyphon solar water heater

Solar Energy ◽

10.1016/j.solener.2005.01.001 ◽

2005 ◽

Vol 79 (5) ◽

pp. 459-468 ◽

Cited By ~ 230

Author(s):

Mehmet Esen ◽

Hikmet Esen

Keyword(s):

Experimental Investigation ◽

Solar Water Heater ◽

Water Heater ◽

Two Phase ◽

Solar Water

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03/02420 Optimization of a natural circulation two phase closed thermosyphon flat plate solar water heater

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(03)92549-5 ◽

2003 ◽

Vol 44 (6) ◽

pp. 392

Keyword(s):

Flat Plate ◽

Natural Circulation ◽

Solar Water Heater ◽

Water Heater ◽

Two Phase ◽

Solar Water

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A Comparative Performance Analysis between Serpentine-Flow Solar Water Heater and Photovoltaic Thermal Collector under Malaysian Climate Conditions

International Journal of Photoenergy ◽

10.1155/2021/7176506 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

M. S. Hossain ◽

Laveet Kumar ◽

Afroza Nahar

Keyword(s):

Thermal Performance ◽

Simulation Models ◽

Energy Conversion Efficiency ◽

Experimental Investigations ◽

Outlet Temperature ◽

Solar Water Heater ◽

Water Heater ◽

Comparative Performance ◽

Climate Conditions ◽

Solar Water

Solar energy has increasingly been employed for domestic and industrial water heating. Both conventional solar water heater (SWH) and photovoltaic thermal (PVT) systems suffer from the drawback of poor energy conversion efficiency. In this article, a unique parallel serpentine-flow thermal collector has been designed and developed that has been employed as an isolated SWH and also integrated with a 32-cell monocrystalline photovoltaic (PV) module. Simulation models of both SWH and PVT systems have been built in TRNSYS to study their thermal performance numerically. Thereafter, outdoor experimental investigations have been conducted under the composite climates of Malaysia. Experimental results show very good agreement with the simulation outcomes with disparity less than 2%. At the optimum flow rate, the maximum thermal efficiencies of SWH and PVT are 82.5% and 74.62%, respectively. Superior water outlet temperature was obtained with SWH. Although SWH exhibits superior thermal performance, PVT’s additional electrical output might make it preferable for several applications.

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