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 ◽  
...  

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.

1992 ◽  
Vol 114 (4) ◽  
pp. 219-226 ◽  
Author(s):  
J. H. Davidson ◽  
W. T. Carlson ◽  
W. S. Duff

A half-factorial, two-level experimental design is used to determine the effects of changes in collector area, storage tank volume, collector flow rate, recirculation flow rate, and storage tank design on thermal rating of a solar drain-back water heating system. Experimental ratings are determined in accordance with the Solar Rating and Certification Corporation guidelines. 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. Statistical analyses indicate that a change in collector area accounts for nearly 90 percent of the variation in heat output. Doubling collector area from 2.78 m2 to 5.56 m2 increases delivered solar energy by 31 percent. Use of a stratification manifold increases the delivery of solar energy by six percent. Doubling collector flow rate from 0.057 to 0.114 1/s increases solar output by approximately three percent; however, the increase in pumping energy outweighs the benefits of increasing collector flow rate. The effects of recirculation flow rate and tank volume are obscured by experimental error.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mehdi Jahangiri ◽  
Esther T. Akinlabi ◽  
Sam M. Sichilalu

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.


1983 ◽  
Vol 62 (1) ◽  
pp. 38-51
Author(s):  
Ken Butti ◽  
John Perlin

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
M. J. R Abdunnabi

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). 


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