A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

scholarly journals Comparison of Short-Term Testing and Long-Term Monitoring of Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (4) ◽  
pp. 274-280
Author(s):  
S. B. Beale
Keyword(s):  
Water Systems ◽  
Hot Water ◽  
Testing Time ◽  
Short Term ◽  
Solar Simulator ◽  
Good Correspondence ◽  
Domestic Hot Water ◽  
Solar Fraction ◽  
Load Schedule

This paper reports on the results of a comparison between short-term indoor testing and long-term outdoor monitoring of solar domestic hot water systems. Five solar-preheat systems were monitored under side-by-side conditions of irradiance and load, for a period of two years. The systems were then tested according to a standard day test, using a solar simulator, and a load schedule identical to that imposed on each system during the monitoring. The systems were found to deliver 19.7 MJ–25.8 MJ daily in the test, compared to a two-year average of 19.1 MJ–26.0 MJ (1.5 to 2.0 GJ/m2 annually) outdoors. System rank was reasonably well preserved. Comparison of results on the basis of efficiency and solar fraction suggests that good correspondence exists between long-term outdoor results and those of indoor testing, at least for systems with stable controllers. Selected systems were also tested at different load schedules and radiation levels. Methods of predicting the performance of a solar-preheat system from the results of a standard day test are discussed, and the possibility of reducing testing time to a single day is explored.

Plume entrainment effects in solar domestic hot water systems employing variable-flow-rate control strategies

Solar Energy ◽  
1992 ◽  
Vol 49 (6) ◽  
pp. 497-505 ◽  
Author(s):  
G.F. Csordas ◽  
A.P. Brunger ◽  
K.G.T. Hollands ◽  
M.F. Lightstone
Keyword(s):  
Flow Rate ◽  
Rate Control ◽  
Control Strategies ◽  
Water Systems ◽  
Hot Water ◽  
Variable Flow ◽  
Domestic Hot Water ◽  
Flow Rate Control

Modeling occupant behavior’s influence on the energy efficiency of solar domestic hot water systems

2022 ◽  
Vol 309 ◽  
pp. 118503
Author(s):  
Xin Zhou ◽  
Shuai Tian ◽  
Jingjing An ◽  
Da Yan ◽  
Lun Zhang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Water Systems ◽  
Hot Water ◽  
Domestic Hot Water
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