scholarly journals Eco-Friendly and Economical Solar Heater Design Using Internal Structure and Phase Change Materials

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7423
Author(s):  
Jihu Lee ◽  
Sung-Hun Son ◽  
Kibum Kim
Keyword(s):  
Phase Change ◽  
Internal Structure ◽  
Air Temperature ◽  
Phase Change Materials ◽  
Operating Conditions ◽  
Internal Space ◽  
Solar Air Heater ◽  
Air Heater ◽  
Solar Heater ◽  
Heater Design

Indoor heating systems currently used are highly dependent on fossil fuels; hence, it is urgent to develop a new heating system to achieve carbon zero-emission. A solar air heater is eco-friendly because it generates nearly zero greenhouse gases. In this study, a parametric study was conducted for optimizing solar air heater design applicable to indoor heating. Installing the internal structure in the solar heater changes the interior flow characteristic, resulting in the air temperature increased by about 14.2 K on average compared to the heater without the internal structure. An additional case study was carried out to optimize the ideal quantity of phase change materials (PCM) in terms of mass fraction and heat capacity for various operating conditions. An excessive amount of PCM (e.g., 66% of the storage space filled with PCM) deteriorates the performance of the air heater unless the entire PCM could be melted during the daytime. After heating, the air temperature was maintained the longest when only 33% of the internal space was filled with PCM. The solar air heater can fully replace or partly assist a conventional heater for indoor heating, and it could reduce approximately 0.6 tCO2 per year.

scholarly journals Flat solar air heater collector with phase change materials for domestic purposes in Iraqi climate

2020 ◽  
Vol 928 ◽  
pp. 022099
Author(s):  
Bashar K Mahmoud ◽  
Sulafa I Ibrahim ◽  
Khaleel I Abass ◽  
Ali J Ali ◽  
Miqdam T Chaichan
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Solar Air Heater ◽  
Air Heater

scholarly journals Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material

2019 ◽  
Vol 25 (2) ◽  
pp. 1-17 ◽  
Author(s):  
Abdulrahman Shakir Mahmood
Keyword(s):  
Experimental Study ◽  
Phase Change ◽  
Phase Change Material ◽  
Air Temperature ◽  
Thermal Performance ◽  
Thermal Storage ◽  
Solar Air Heater ◽  
Double Pass ◽  
Air Heater ◽  
Change Material

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.  

Design and Development of V-Grooved Natural Convection Solar Air Heater for Odisha

2015 ◽  
Vol 813-814 ◽  
pp. 668-673
Author(s):  
D.V.N. Lakshmi ◽  
S.S. Mohapatra ◽  
Anbalgan Satheesh ◽  
Harish Das
Keyword(s):  
Experimental Study ◽  
Natural Convection ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Flow Rate ◽  
Meteorological Conditions ◽  
Second Law ◽  
Solar Air Heater ◽  
Air Heater ◽  
Solar Heater

This paper presents an experimental study of natural convection V-grooved solar heater. Based on the experimental study, the first law and second law efficiencies and entropy generation have been calculated considering the available radiation under the meteorological conditions of Bhubaneswar, Odisha, India. Experiments were conducted during the month of November 2014 to March, 2015 for studying the performance characteristics of the solar air heater. The results obtained are quite significant with respect to outlet air temperature as compared to other solar heaters. The maximum air heater efficiency was found to be 16.91%, calculated at a mass flow rate of 3.55 gm/s of air and the second law efficiency was 6.72%.

scholarly journals Energy Saving and Charging Discharging Characteristics of Multiple PCMs Subjected to Internal Air Flow

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 275
Author(s):  
Ahmed J. Hamad
Keyword(s):  
Phase Change ◽  
Energy Saving ◽  
Air Temperature ◽  
Temperature Control ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Heating System ◽  
Air Heating ◽  
Room Model ◽  
Model Temperature

One essential utilization of phase change materials as energy storage materials is energy saving and temperature control in air conditioning and indirect solar air drying systems. This study presents an experimental investigation evaluating the characteristics and energy savings of multiple phase change materials subjected to internal flow in an air heating system during charging and discharging cycles. The experimental tests were conducted using a test rig consisting of two main parts, an air supply duct and a room model equipped with phase change materials (PCMs) placed in rectangular aluminum panels. Analysis of the results was based on three test cases: PCM1 (Paraffin wax) placed in the air duct was used alone in the first case; PCM2 (RT–42) placed in the room model was used alone in the second case; and in the third case, the two PCMs (PCM1 and PCM2) were used at the same time. The results revealed a significant improvement in the energy savings and room model temperature control for the air heating system incorporated with multiple PCMs compared with that of a single PCM. Complete melting during the charging cycle occurred at temperatures in the range of 57–60 °C for PCM1 and 38–43 °C for PCM2, respectively, thereby validating the reported PCMs’ melting–solidification results. Multiple PCMs maintained the room air temperature at the desired range of 35–45.2 °C in the air heating applications by minimizing the air temperature fluctuations. The augmentation in discharging time and improvement in the room model temperature using multiple PCMs were about 28.4% higher than those without the use of PCMs. The total energy saving using two PCMs was higher by about 29.5% and 46.7% compared with the use of PCM1 and PCM2, respectively. It can be concluded that multiple PCMs have revealed higher energy savings and thermal stability for the air heating system considered in the current study.

Natural Convection in an Enclosure With Blend of Micro Encapsulated Phase Change Materials

2013 ◽  
Author(s):  
Yasmin Khakpour ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Heat Transfer ◽  
Thermal Expansion ◽  
Natural Convection ◽  
Phase Change ◽  
Latent Heat ◽  
Phase Change Materials ◽  
Numerical Study ◽  
Pure Water ◽  
Operating Conditions ◽  
Effective Density

This numerical study investigates the effect of using a blend of micro-encapsulated phase change materials (MEPCMs) on the heat transfer characteristics of a liquid in a rectangular enclosure driven by natural convection. A comparison has been made between the cases of using single component MEPCM slurry and a blend of two-component MEPCM slurry. The natural convection is generated by the temperature difference between two vertical walls of the enclosure maintained at constant temperatures. Each of the two phase change materials store latent heat at a specific range of temperatures. During phase change of the PCM, the effective density of the slurry varies. This results in thermal expansion and hence a buoyancy driven flow. The effects of MEPCM concentration in the slurry and changes in the operating conditions such as the wall temperatures compared to that of pure water have been studied. The MEPCM latent heat and the increased volumetric thermal expansion coefficient during phase change of the MEPCM play a major role in this heat transfer augmentation.

scholarly journals Thermohydraulic Performance and Entropy Generation of a Triple-Pass Solar Air Heater with Three Inlets

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6399
Author(s):  
Nguyen Minh Phu ◽  
Ngo Thien Tu ◽  
Nguyen Van Hap
Keyword(s):  
Reynolds Number ◽  
Air Temperature ◽  
Entropy Generation ◽  
Solar Air Heater ◽  
Minimum Entropy ◽  
Air Heater ◽  
The Third ◽  
Thermohydraulic Efficiency ◽  
The Difference ◽  
Minimum Entropy Generation

In this paper, a triple-pass solar air heater with three inlets is analytically investigated. The effects of airflow ratios of the second and third passes (ranging from 0 to 0.4), and the Reynolds number of the third pass (ranging from 8000 to 18,000) on the thermohydraulic efficiency and entropy generation are assessed. An absorber plate equipped with rectangular fins on both sides is used to enhance heat transfer. The air temperature change in the passes is represented by ordinary differential equations and solved by numerical integration. The results demonstrate that the effect of the third pass airflow ratio on the thermohydraulic efficiency and entropy generation is more significant than that of the second pass airflow ratio. The difference in air temperature through the collector shows an insignificant reduction, but the air pressure loss is only 50% compared with that of a traditional triple-pass solar air heater. Increasing the air flow ratios dramatically reduces entropy generation. Multi-objective optimization found a Reynolds number of 11,156 for both the airflow ratio of the second pass of 0.258 and airflow ratio of the third pass of 0.036 to be the an optimal value to achieve maximum thermohydraulic efficiency and minimum entropy generation.

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