scholarly journals Experimental Investigation of the Thermal Performance of a Solar Air Heater

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Abdulghani M. Ramadan ◽  
Khairi Muftah ◽  
Abdul-Rahman Al-Naaji ◽  
Abdul-Baset Al-Soul ◽  
Akram A. Essnid ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Solar Radiation ◽  
Mass Flow ◽  
Thermal Performance ◽  
Operating Conditions ◽  
Space Heating ◽  
Solar Air Heater ◽  
Air Mass ◽  
Incident Solar Radiation ◽  
Air Heater

Solar air heaters are widely used in many low temperature applications such as space heating, crops drying, desalination..etc. It collects solar radiant energy and transforms it into heat through a fluid (air) flowing inside the system. The outside cold air is heated through the system and delivered to the required application. It is simple, economic and clean. In this study, an experimental investigation is carried out using a test-rig installed at the laboratories facility for Center of Solar Energy Research and Studies (CSERS) in Tajoura-Libya equipped with all necessary measuring instruments and devices. The aim of this study is to investigate the effect of process air mass flow rate on the thermal performance of a solar air heater working at different operating conditions under the prevailing conditions of Tajoura-Libya. Experiments were conducted on specified days in August 2019, October 2019 and January, 2020.Results show that there is a noticeable increase in the air temperatures of the solar air heater as incident solar radiation values increase during the day time, especially at afternoon. The maximum average outlet air temperature measured reaches 60 oC which is suitable for space heating and crops drying applications. Useful heat energy collected is directly proportional to the incident solar radiation. Increasing air mass flow rates leads to a corresponding decrease in the temperature at different locations in the solar air heater. Furthermore, the average thermal efficiency values of the solar air heater range from 35% to 65%. Average overall heat loss coefficient values tend to decrease with the day time. Finally, the present study results coincide with literature and show a good agreement.

Experimental Investigation on Thermal Performance in Three-Sided Solar Air Heaters Having an Alignment of Multi-v and Transverse Wire Roughness on the Absorber Plate

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Dhananjay Kumar ◽  
Laljee Prasad
Keyword(s):  
Thermal Performance ◽  
Thermal Efficiency ◽  
Roughness Height ◽  
Space Heating ◽  
Solar Air Heater ◽  
Artificial Roughness ◽  
Absorber Plate ◽  
Air Heater ◽  
Relative Roughness ◽  
Operational Constraints

Abstract The use of artificial roughness is an efficient and commercial way to appreciate the thermal performance from the collector to the air in solar air heater ducts, for numerous applications such as space-heating, crop-drying, and seasoning of timber industrial purpose. In this paper, the tentative inquiry on thermal enactment using new-fangled of three-sided roughened quadrilateral duct solar air heater having an alignment of multiple-v and transverse wire is performed and compared the outcomes with smooth duct air heater under similar operational circumstances. The modification of an arrangement and operational constraints is inspected within the restrictions, the moral of four-sided duct aspect ratio (W/H) = 8, the Reynolds number occupied from 3000 to 12,000, fraction of pitch to roughness height, P/e in the range of 10–25; ratio of roughness height to hydraulic diameter, e/D in the range of 0.018–0.042; at flow attack angle, α = 60 deg for constant moral of relative roughness width, (W/w) = 6. The augmentation on thermal efficiency in three-sided rugged duct is found to be 23–86% when compared to smooth duct, and the maximum thermal efficiency can occur at P/e = 10 and e/D = 0.042. The enhancement in air temperature flowing under three-sided roughened duct is found to be 49.27% more than that of a smooth duct. The instant innovative form of three-sided roughened solar air warmer would be preferable to those of a smooth solar air heater with respect to heat assignment.

scholarly journals Effects of Louvered Parameters on Exergetic Performance of Louvered Finned Solar Air Heater

2021 ◽  
Vol 39 (5) ◽  
pp. 1649-1658
Author(s):  
Subhash Chand ◽  
Prabha Chand
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Operating Conditions ◽  
High Mass ◽  
Solar Air Heater ◽  
Air Heater ◽  
Pitch Ratio ◽  
Exergy Performance

The aim of the present study to improve the performance of solar air heater because of low thermo-physical properties of air. In the current work, an attempt has been made to improve the performance of the heater by employing louvered fins to the absorber plate, as it not only enhances heat transfer coefficient but also improve heat transfer area. The effect of exergy performance on the geometrical parameters of louvered fin i.e., louvered angle, louvered pitch and louvered length has been studied and analyzed. The results are compared to plane solar air heater (PSAH) to evaluate the effectiveness of louvered finned solar air heater (LFSAH). The exergy efficiency of LFSAH is comparatively higher for all the operating conditions except for higher mass flow rate where it may even go below that of PSAH; possibly due to the higher pressure drop and more loss of exergy at high mass flow rate. In addition, the results conclude that for louvered parameters viz., louvered angle 20°, fin pitch to louvered pitch ratio 0.75 and louvered length to louvered pitch ratio 1.25, high exergy performance of SAH is obtained as compared to other louvered parameter values.

scholarly journals Mathematical Modelling of Single Glazed and Double Glazed Solar Air Heater

2021 ◽  
Vol 10 (3) ◽  
pp. 34-42
Author(s):  
Bhawna Agrawal ◽  
Pallavi Agrawal ◽  
Suman Agrawal
Keyword(s):  
Solar Radiation ◽  
Mathematical Modelling ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Winter Season ◽  
Solar Air Heater ◽  
Counter Flow ◽  
Heat Gain ◽  
Air Heater

This paper focuses on Mathematical Modelling of Single Glazed and Double Glazed Solar air heater (SAH) which is special kind of heat exchanger that transfers thermal energy from the solar radiation to the fluid flowing inside of the collector. The most potential applications of SAH is the supply of hot air for heating of buildings, to maintain a comfortable environment especially in the winter season, air preheating, desiccant refrigeration, and drying of vegetables, fruits, meat, textile and marine products. Solar radiation intensity is less in the morning that increase gradually till noon and again decrease from noon to evening. During simulations it is observed that the heat gain is directly proportional to the mass flow rate. It is maximum for the counter flow SAH and is least for transpired solar air heater. The efficiency of the SAH is directly proportional to mass flow rate. The thermal efficiency is maximum for the counter flow SAH, The useful heat gain increases is highest in the clear days of summer month particularly in the month of April-May and lowest in the cloudy days of winter month particularly in the month of December. The results are in conformation with theoretical aspects.

scholarly journals Experimental Study of Artificial Solar Air Heater Using Trapezoidal Wave Plate

2019 ◽  
Vol 4 (2) ◽  
pp. 135-148
Author(s):  
Lohdy Diana ◽  
Arrad Ghani Safitra ◽  
Muhammad Syarifuddin Firmansyah ◽  
Mishbaakhus Prana Zinedine
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Airflow Rate ◽  
Halogen Lamp ◽  
Solar Air Heater ◽  
Air Mass ◽  
Wave Plate ◽  
Air Heater ◽  
Air Heating

A solar air heater is needed for the drying process, especially in Indonesia.  It means the researches to produce a solar air heater that had high performance is necessary. This research analyses the performance of solar air heater using trapezoidal absorber plate with variation of folded angle 83˚, 85˚, and 87˚. The research carry out artificial experimentally using halogen lamp as a solar simulator. The working principle of solar air heating begins with an induction fan sucking air to enter through the honeycomb then flowing into the air heating duct. The process of heat transfer occurs in a halogen heat lamp passed by the transparent glass and then absorbed by the absorbent plate. This heat will heat the air flowing in the air heating pipe to be transmitted into the drying cupboard. The experiment used several variations of the mass airflow rate 0.022 until 0.051 kg/s and intensity 850, 900, dan 950 W/m2. Temperature measurement is carried out by installing a thermocouple at several points that have been determined. The best performance produced by the wave plate-shaped trapezoidal wave heaters 83˚ when I = 950 W/m2 air mass flow rate 0.022 kg/s with the temperature of the absorbent plate 87 ˚C, the temperature of the exit air 43.2 ˚C, the difference in the rise in air temperature 15.2 ˚C, and when I = 950 W/m2 air mass flow rate 0.051 kg/s the useful heat generated by the air heater 527 Watt, and thermal efficiency 96.8%.

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