scholarly journals Optimum Values of Tank Volume to Collector Area Ratios of Thermosyphon Solar Water Heaters for Libyan Families

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
M. J. R Abdunnabi
Keyword(s):  
Optimization Technique ◽  
Operating Conditions ◽  
Hot Water ◽  
Weather Data ◽  
Active System ◽  
Solar Water ◽  
Water Heaters ◽  
Temperature Ranges ◽  
Solar Water Heaters ◽  
Auxiliary Heater

Thermosyphon solar water heaters are the best choice to be utilized in residential sector to provide the required hot water in Libya. These systems are autonomy in operation and as a result require less maintenance and hence low operation and initial costs than active system. ln this paper, GenOpt optimization technique provided in TRNSYS simulation program is used for sizing Thermosyphon systems to obtain the optimum size (namely V/A ratio) of Thermosyphon system that suits Libyan families according to the weather and operating conditions of Tripoli. The typical hot water load pattern and quantity of the Libyan families are taken from a field study conducted on a number of solar system for a whole year. Whereas, the typical weather data are taken from five year measurements recorded at CSERS weather station. The results showed that the optimum storage tank volume to collector area ratio of Thermosyphon systems is between 49-60 Lit/m2 for the most common collector characteristics ratio (equation!!) and the auxiliary heater set point temperature ranges from (45-60C). 

scholarly journals Assessment and Modeling of Household-Scale Solar Water Heater Application in Zambia: Technical, Environmental, and Energy Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mehdi Jahangiri ◽  
Esther T. Akinlabi ◽  
Sam M. Sichilalu
Keyword(s):  
Fossil Fuels ◽  
Hot Water ◽  
Climate Data ◽  
Ghg Emission ◽  
Water Heater ◽  
Ghg Mitigation ◽  
Solar Water ◽  
Water Heaters ◽  
Industrial Sectors ◽  
Solar Water Heaters

Solar water heaters (SWHs) are one of the most effective plans for general and easy use of solar energy to supply hot water in domestic and industrial sectors. This paper gives the first-ever attempts to assess the optimal localization of SWHs across 22 major cities in Zambia, as well as determine the possibility of hot water generation and model the greenhouse gas (GHG) emission saving. The climate data used is extracted by using the MeteoSyn software which is modeled in TSOL™. Results show the high potential of GHG emission reduction due to nonconsumption of fossil fuels owing to the deployment of SWHs, and three cities Kabwe, Chipata, and Mbala had the highest GHG mitigation by 1552.97 kg/y, 1394.8 kg/y, and 1321.39 kg/y, respectively. On average, SWHs provide 62.47% of space heating and 96.05% of the sanitary hot water requirement of consumers. The findings have shown the potential for the deployment of SWHs in Zambia. The techno-enviro study in this paper can be used by the policymakers of Zambia and countries with similar climates.

Free Hot Water Day & Night Solar Water Heaters in California

1983 ◽  
Vol 62 (1) ◽  
pp. 38-51
Author(s):  
Ken Butti ◽  
John Perlin
Keyword(s):  
Hot Water ◽  
Solar Water ◽  
Water Heaters ◽  
Solar Water Heaters

Performance and Modeling of Thermosyphon Heat Exchangers for Solar Water Heaters

1997 ◽  
Vol 119 (3) ◽  
pp. 193-200 ◽  
Author(s):  
S. D. Dahl ◽  
J. H. Davidson
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Heating Systems ◽  
Solar Water ◽  
Water Heaters ◽  
Prandtl Numbers ◽  
Area Product ◽  
Solar Water Heaters

Determining the performance of indirect solar heating systems that use thermosyphon heat exchangers requires knowledge of how thermosyphon flow rate and heat exchanger performance vary with operating conditions. In this paper, measured performance of a two-pass, tube-in-shell, double-wall heat exchanger is discussed in terms of modeling issues. Thermosyphon heat exchangers may operate in the developing, mixed convection regime where natural convection effects can significantly influence overall heat transfer and friction coefficients. Existing models which assume the thermal and hydraulic behaviors of thermosyphon heat exchangers are only functions of the thermosyphon and collector flow rates may not be suitable for all heat exchanger types. For example, the overall heat-transfer coefficient-area product for the two-pass, tube-in-shell heat exchanger is best expressed as a function of Reynolds, Grashof, and Prandtl numbers on the thermosyphon side of the heat exchanger. It is proposed that annual simulations of solar water heaters with thermosyphon heat exchangers use this type of relationship to characterize heat transfer in the heat exchanger.

scholarly journals Assessment of Uncertainties in Energetic and Exergetic Performances of a Flat Plate Solar Water Heater

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Intissar Harrabi ◽  
Mohamed Hamdi ◽  
Majdi Hazami
Keyword(s):  
Flat Plate ◽  
Multiwall Carbon Nanotubes ◽  
Operating Conditions ◽  
Working Fluid ◽  
Water Heater ◽  
Solar Water ◽  
Water Heaters ◽  
Proposed Model ◽  
Energy And Exergy ◽  
Solar Water Heaters

This paper aims to quantify sensitivities of energy and exergy performances of Flat Plate Solar Water Heaters (FPSWHs) with respect to measurement parameters. For that purpose, a computational tool is developed and validated by using outdoor conditions according to the test standard EN 12975. First of all, numerical simulations are compared with experimental results and available data in the literature, and the comparison shows a good agreement. Then, we apply the proposed model to the quantification of uncertainties associated with transient simulation. Results show that ambient temperature is the main relevant factor in operating conditions, and its effect reaches 13.7% and 3.89% on energy and exergy efficiencies, respectively, when the deviation in the sensor measurement is about ±1°C. When 0.15 v% multiwall carbon nanotubes (MWCNT)-Ethylene-Glycol (E-G) (30 : 70) nanofluid is used as working fluid, results show that a suitable choice of nanofluid properties achieves 84.7% of the thermal efficiency during the zero reduced temperature conditions compared to 75.4% when the collector works with E-G. Using common empirical correlations affects substantially the accuracy of the fitting parameters, and the deviation in exergy efficiency reaches 1.18%.

Comparison of Experimental and Simulated Thermal Ratings of Drain-Back Solar Water Heaters

1993 ◽  
Vol 115 (2) ◽  
pp. 101-105 ◽  
Author(s):  
J. H. Davidson ◽  
W. T. Carlson ◽  
W. S. Duff ◽  
P. J. Schaefer ◽  
W. A. Beckman ◽  
...  
Keyword(s):  
Flow Rate ◽  
Storage Tank ◽  
Experimental Tests ◽  
Hot Water ◽  
Drop Tube ◽  
Recirculation Flow ◽  
Solar Water ◽  
Water Heaters ◽  
Tank Design ◽  
Solar Water Heaters

Short-term experimental tests of drain-back solar water heaters are compared to ratings obtained using TRNSYS to determine if computer simulations can effectively replace laboratory thermal ratings of solar domestic hot water heating systems. The effectiveness of TRNSYS in predicting changes in rating due to limited changes in collector area, collector flow rate, recirculation flow rate, storage tank volume, and storage tank design is validated to within ±10 percent. Storage tank design is varied by using a stratification manifold in place of the standard drop tube. Variations in other component sizes and operating factors are based on current industry standards.

scholarly journals Energy Efficiency for Social Buildings in Morocco, Comparative (2E) Study: Active VS. Passive Solutions Via TRNsys

Inventions ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Fatima Zohra Gargab ◽  
Amine Allouhi ◽  
Tarik Kousksou ◽  
Haytham El-Houari ◽  
Abdelmajid Jamil ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Building Envelope ◽  
Hot Water ◽  
Solar Water Heater ◽  
Water Heater ◽  
Climatic Zones ◽  
Solar Water ◽  
Water Heaters ◽  
Solar Water Heaters

This paper aims to highlight the potential of solar water heater installations in Morocco. The project involves the comparison of active and passive solutions for energy efficiency in buildings. To this end, a numerical simulation model of solar water heater installations is created under TRNsys. Three hot water demand scenarios (Low, Standard, and High) were taken into account for the six climatic zones defined in the Moroccan thermal regulation of constructions. The same software (TRNsys) is used to model a pilot building consisting of 16 flats. Energy efficiency actions have been applied to the building envelope (insulation and glazing) and simulations are made for the six areas. The simulation results comparing energy and financial savings show the influence of subsidized gas prices on solar water heaters’ relevance despite significant energy savings. This work proves that solar water heaters will be a primary obligation for Morocco, taking into account changes in butane gas prices.

scholarly journals Review on solar water heating in Libya

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Mohammad Abdunnabi ◽  
Ibrahim Rohuma ◽  
Essam Endya ◽  
Esmaeel Belal
Keyword(s):  
Hot Water ◽  
Decision Makers ◽  
Wide Spread ◽  
Water Heating ◽  
Solar Water Heating ◽  
Solar Water ◽  
Water Heaters ◽  
Industrial Sectors ◽  
Solar Water Heaters ◽  
Annual Amount

This review paper aims to provide a comprehensive review of the history and the best practices of solar water heaters in Libya. Although, Libya is blessed with high solar potential, there is no wide-spread implementation of this technology due to many reasons such as: the cheap price of both electricity and electric water heaters, lack of clear and systematic policy, and lack of environmental awareness. The Center for Solar Energy Research and Studies (CSERS) has given attention to this technology since its establishment in 1978, and the solar water heating system field test project is one of the research projects in the Center. The paper has shown that there was no attention paid to this technology and even to renewable energy in general in the previous years. However, preliminary information clearly shows the importance of continuing research in this field. Numerous valuable information on solar water heating systems from literature were dedicated and made available for researchers and decision makers. The studies conducted in this field for Libya are arranged in this review on the bases of the topic studied: performance evaluation, optimization, on-site measurements and policies and strategies. One of the most important results retrieved from these studies show that the daily quantity of hot water withdrawn per capita at 45 °C is estimated around 60 liters. The estimated annual amount of energy consumed for water heating per person is 510 kWh. For average Libyan family of six persons, the annual amount of energy consumed per dwelling is estimated about 3060 kWh. The review also presented the history of solar water heaters implementation, manufacturing and testing facilities for quality control in Libya. The study calls upon the Libyan decision makers to take their responsibility and put an urgent action plan to help the wide-spread implementation of solar water heaters in the residential, services and industrial sectors. Such a plan will surely alleviate the ever increasing demand for electricity, save fossil fuel reserves and mitigate GHG emissions.

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