Temperature Evolution of Evacuated Tube Adsorbtion Bed Heated by Solar Radiation

Author(s):  
Chun-Xu Du ◽  
Zhong-Xian Yuan ◽  
Xiao-Huang Hou ◽  
Feng Xin ◽  
Dong-Dong Gao ◽  
...  

Instant hot water requirement is more in tropical countries during the winter season. The conventional flat plate collector and evacuated tube collector based solar water heaters are unable to delivesr instant hot water in the presence of low solar radiation. Passive heating of water in an evacuated tube with heat transfer fluids having low specific heat can deliver a better solution to the above problem. Therminol D-12 was identified as one such fluid and its performance was studied under varying flow rates and radiation heat fluxes. The analysis was carried out with the CFD solver FLUENT 6.2. P1 radiation model was used to predict the static temperature and velocity magnitude of therminol D-12 at the exit of the evacuated tube. The result obtained from the CFD analysis was validated with the experimental result. The deviation of experimental result from the predicted result was found to be less than 5%. The error percentage increases with increasing radiative heat fluxes due to convection boundary conditions. The performance of P1 model was found to be good for solar radiation experiments less than 600 W/m2 .


2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Kajewole Emmanuel Dami ◽  
Ricardo Beltran-Chacon ◽  
Saul Islas ◽  
Daniel Leal-Chavez

Abstract This paper analyzes the direct solar vapor generation of acetone by solar radiation falling on the heat pipes of an evacuated tube collector (ETC) that can activate a domestic scale organic Rankine cycle (ORC). The irradiance from the sun determines the mass flow of acetone along the horizontal manifold of the ETC to produce vapor at the collector outlet. A scilab code is developed to simulate the flow of acetone inside the manifold where subcooled acetone undergoes heating and evaporation process. Simulation is run from 60 °C to a saturation temperature of 120 °C at a pressure of 604 kPa, vapor qualities from 1% to 100%, and solar radiation from 300 to 1100 W/m2. The Kattan–Thome–Favrat flow boiling model is used to obtain the two-phase local heat transfer coefficients along the horizontal manifold, and it is validated with the numerical and experimental values of ammonia. The ORC system can generate 218 kWh/year of electrical energy, a thermal power capacity of 1616 kWh/year and achieve an ORC efficiency of 84.4%. The solar-ORC has a thermal efficiency of 3.25% and an exergy efficiency of 21.3% with a solar collector of 2.84 m2.


Energy ◽  
2020 ◽  
Vol 198 ◽  
pp. 117331 ◽  
Author(s):  
Gholamabbas Sadeghi ◽  
Anna Laura Pisello ◽  
Habibollah Safarzadeh ◽  
Miad Poorhossein ◽  
Mohammad Jowzi

2014 ◽  
Vol 11 (1) ◽  
pp. 111-115
Author(s):  
Baghdad Science Journal

The aim of this work was to capture solar radiation and convert it into solar thermal energy by using a storage material and the heat transfer fluid like oil and water and comparison between them, we used the evacuated tube as a receiver for solar radiation, The results showed that the oil better than water as storage material and the heat transfer fluid and the effective thermal conductivity material and good for power level, rates and durations of charge and discharge cycles.


Space Weather ◽  
2006 ◽  
Vol 4 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Tracy Staedter
Keyword(s):  

2003 ◽  
Vol 107 ◽  
pp. 743-747
Author(s):  
D. R.S. Lean ◽  
SD. Siciliano
Keyword(s):  

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