Thermal performance of a packed bed double-pass solar air heater

Energy ◽  
2007 ◽  
Vol 32 (8) ◽  
pp. 1524-1535 ◽  
Author(s):  
M.R.I. Ramadan ◽  
A.A. El-Sebaii ◽  
S. Aboul-Enein ◽  
E. El-Bialy
2011 ◽  
Vol 8 (1) ◽  
pp. 101-105
Author(s):  
M. K. Lalji ◽  
R. M. Sarviya ◽  
J. L. Bhagoria

Solar energy is an economical alternative to the today's energy demand. Solar air heater is used for heating the air economically but produces low thermal efficiency. In this paper, an attempt has been made to study the design of solar heaters to increase the thermal efficiency. The matrix solar air heater with a wire mesh produces higher thermal efficiency over the conventional flat plate solar air heater. The evaluation of different methods for increasing efficiency of packed bed solar air heater has been done . Effect of different parameters on thermal efficiency of solar heater has also been studied.


2007 ◽  
Vol 48 (3) ◽  
pp. 990-1003 ◽  
Author(s):  
A.A. El-Sebaii ◽  
S. Aboul-Enein ◽  
M.R.I. Ramadan ◽  
E. El-Bialy

2019 ◽  
Vol 25 (2) ◽  
pp. 1-17 ◽  
Author(s):  
Abdulrahman Shakir Mahmood

In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant air mass flow rate of (0.0375 kg/sec). The parameters that affect the thermal performance of the SAH with and without the PCMs presented by solar radiation, the difference in air temperature, outlet air temperature, instantaneous thermal efficiency, and daily efficiency are evaluated. The experimental results show that when using the PCM, the temperature of the outlet air was enhanced and increased over the ambient temperature by (1.5 - 6.5 C) after sunset for 5 hours period. It was found that the instantaneous thermal efficiency of the heater using thermal storage exceeds 100% after sunset, this is due to a large amount of heat stored in the paraffin wax that has been released during the discharge process. Also, it was found that the daily efficiency of the double pass SAH integrated with and without thermal energy storage unit was (56, 47%) respectively.  


2019 ◽  
Vol 15 ◽  
pp. 100543 ◽  
Author(s):  
Muhammad Sajawal ◽  
Tauseef-ur Rehman ◽  
Hafiz Muhammad Ali ◽  
Uzair Sajjad ◽  
Ali Raza ◽  
...  

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman

The present work intended to investigate thermal and thermohydraulic efficiencies of two different models of recyclic double pass packed bed solar air heaters experimentally. Model-I consists of single air pass through two glass covers as well as double air pass caused due to recycle of the air exiting from the packed bed duct formed between the absorber plate and the glass cover through another duct integrated between the absorber and back plates to inlet of the packed bed duct. On the other hand, model-II consists of only double air pass originated due to recycle operation constituted between the similar solar air heater elements as that of model-I. Twelve numbers of wire mesh screens to form 95% bed porosity were used. Both solar air heater models were tested under the range of packed bed Reynolds number from 300 to 1500 for air mass flow rate and recycle ratio of 0.01 kg/s to 0.025 kg/s and 0.3 to 1.8, respectively. Results revealed that thermal performance of model-I is found to be 15% higher than that of model-II. The optimum value of the recycle ratio for model-I and model-II are obtained as 0.9 and 1.2, respectively, at a mass flow rate of 0.025 kg/s that yields the best thermohydraulic efficiency of 77% and 67%, respectively. Moreover, optimum solution for recycle ratio and air mass flow rate during off sun shine hours are also obtained and presented in the current work.


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