96/04039 Thermal performance of solar water heaters

1996 ◽  
Vol 37 (4) ◽  
pp. 281
2020 ◽  
Vol 27 (4) ◽  
pp. 1273-1289
Author(s):  
Da-peng Li ◽  
Yu-fan Wang ◽  
Gang Liu ◽  
Sheng-ming Liao ◽  
Xian-ping Liu

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1615 ◽  
Author(s):  
Ruth Saint ◽  
Céline Garnier ◽  
Francesco Pomponi ◽  
John Currie

2012 ◽  
Vol 30 ◽  
pp. 1365-1371 ◽  
Author(s):  
He Tao ◽  
Zhang Lei ◽  
Deng Yu ◽  
Huang Zhulian ◽  
Wang Xuan ◽  
...  

2013 ◽  
Vol 860-863 ◽  
pp. 81-87
Author(s):  
Yu Qin Yang ◽  
Run Sheng Tang

In the present specification of domestic solar water heating systems (GB/T19141), regardless of the type of collectors used in the systems, Q17, the daily heat gain corresponding to the daily radiation of 17MJ/m2 on the collector surface, is a key indication to rate the thermal performance of a domestic solar water heaters. In this work, an attempt was made to investigate effect of the distance between two adjacent tubes in solar tube collectors of a water-in-glass evacuated tube solar water heater (ETSWH) on by theoretical calculations and experimental measurements. Results obtained by simulations and experimental test showed that the tube space had a significant effect on of the ETSWH, the shorter the tube distance, the higher the Q17, thus better the ETSWH performs. However, the actual situation is the case, the shorter the tube distance, the lower the real daily solar gain of the system, thus worse it performs. This implied that Q17 as the indication of thermal performance of the ETSWH is not reasonable, and specifying the tube distance in solar tube collectors of the ETSWH in the technical specification of GB/T19141 is advisable so as to eliminate effect of the tube distance on Q17.


2020 ◽  
Vol 9 (3) ◽  
pp. 401-410
Author(s):  
Blaise Kamenan Koua ◽  
Paul Magloire Ekoun Koffi ◽  
Prosper Gbaha

 The aim of this study is to present the comparative results of experimental investigations of the thermal performance of two thermosiphon solar water heaters system (SWHS). The first uses the coconut fiber (CF), a local vegetable and the second, the glass wool (GW), an imported and expensive material, as thermal insulations. The maximum instantaneous efficiencies are, respectively, 65.30 % and 58.7% with glass wool and coconut fiber while the mass flow rate values are, respectively, 0.0098 kg/s and 0.0078 kg/s with glass wool and coconut fiber. In addition, the calculated average values of F’(τα) and F’UL are, respectively, 0.79 and 5.86 Wm-2°C for the coconut fiber collector and 0.8 and 5.26 Wm-2°C for the glass wool collector. The average heat exchanger effectiveness obtained for the two SWHS are superior to 50%. As an environment-friendly and renewable material, coconut fiber is particularly suitable for thermal insulation in order to save energy. The experimental results show the ability of the constructed solar water heater in providing hot water suitable for maternity, hotels, households and encourage its implementation and utilization on a broad scale. The SWHS can be used in any weather conditions. ©2020. CBIORE-IJRED. All rights reserved


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