Second law optimization of flat-plate solar air heaters Part I: The concept of net exergy flow and the modeling of solar air heaters

Altfeld, K.; Leiner, Wolfgang; Fiebig, M.

doi:10.1016/0038-092x(88)90128-4

Cited by 129 publications

(23 citation statements)

References 10 publications

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“…Take a house with the built-up area of 40 m 2 The correlation between the friction factor and Reynolds number for the collector with perforating corrugated plate was:…”

Section: Economic Analysismentioning

confidence: 99%

“…To improve the thermal performance of the solar air collectors, researchers have investigated several types of collectors with different sizes, shapes, layouts, materials, and so on. Some of them also studied the effects of structural and operating parameters on the thermal performance of the improved collectors [2,3]. Li et al [4,5] studied the thermal performance of a glazed transpired solar air collectors with slit-like perforations.…”

Section: Introductionmentioning

confidence: 99%

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Experimental Investigation of the Transpired Solar Air Collectors and Metal Corrugated Packing Solar Air Collectors

et al. 2017

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Abstract:The thermal performance of three novel solar air collectors with perforating corrugated plate, slit-perforated plate, and corrugated packing were experimentally studied in this paper. Experiments were conducted in Tianjin to study the thermal and dynamic performance of the collectors in cold and severe cold regions. A chamber with a PID (Proportion Integration Differentiation) temperature controller was designed to control the inlet air temperature of the three collectors. Effects of radiation intensity, inlet air temperature, and flow rate on the thermal efficiency and outlet air temperature were experimentally studied. The results indicated that the thermal efficiency of the three collectors in severe cold regions could be much higher than 50% and the collector with perforating corrugated plate had the highest thermal efficiency. The inlet air flow rate had significant effects on the thermal comfort of buildings in cold and severe cold regions and it should be lower than 45 m 3 /h. The results indicated that the pressure drops of collectors with perforating corrugated plate were a little larger than the collectors with slit-perforated plate, but the thermal efficiency and outlet air temperature was higher. Therefore, the collector with perforating corrugated plate was more suitable to use in cold and severe cold regions.

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“…Take a house with the built-up area of 40 m 2 The correlation between the friction factor and Reynolds number for the collector with perforating corrugated plate was:…”

Section: Economic Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Transpired Solar Air Collectors and Metal Corrugated Packing Solar Air Collectors

et al. 2017

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“…The destroyed exergy,

E x_{d e s t}

, is the result of three terms: The absorber surface and sun temperature difference :

E x_{d e s t} (p - s) = - η_{0} I_{T} A_{c} T_{a} false((1 / T_{p}) - (1 / T_{s}) false) .

The duct pressure drop :

E x_{d e s t} (Δ P) = - (Δ P T_{a} / ρ) false(T_{a} \ln ({normalT}_{out} / {normalT}_{normala}) false) / (T_{o u t} - T_{i n}) .

The heat transfer from absorber plate to fluid :

E x_{d e s t} (p - f) = - \dot{m} C_{p} T_{a} false(\ln (T_{o u t} / T_{i n}) - (T_{o u t} - T_{i n} / T_{p}) false) .

…”

Section: Energy and Exergy Analysis Of The Equipped Solar Air Heater mentioning

confidence: 99%

Energy and Exergy Analysis of a Single-Pass Sequenced Array Baffled Solar Air Heater with Packed Bed Latent Storage Unit for Nocturnal Use

Ghiami

Kianifar

Aryana

et al. 2016

Heat Trans. Asian Res.

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The current study presents an experimental investigation on evaluation of thermal performance of a single-pass double-glazed solar air heater with the use of packed bed paraffin wax as a phase change material (PCM). Moreover, the absorber plate is equipped with baffles attached over its top. Galvanized sheets with a thickness of 0.4 mm and total surface areas of 30 cm 2 are chosen as baffles that are placed in a sequential manner over the absorber plate. The solar energy was stored in the packed bed PCM during the diurnal period (charging process) and was released at night for nocturnal use (discharging process). The tests were performed at three different mass flow rates of 0.009 kg∕s, 0.014kg∕s, and 0.017kg∕s, resulting in the creation of different Reynolds numbers along the channel. The measured parameters were inlet, outlet, and the PCM temperatures under the meteorological condition of Mashhad, Iran. Energy and exergy efficiencies of the system have been calculated according to the first and second laws of thermodynamics. The experimental results illustrate that the daily energy efficiency varied between 20.7% and 26.8%, whereas the daily exergy efficiency varied between 10.

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“…Karsli [17] determined the first and second laws of efficiencies of four types of air heating flat-plate solar collectors. Altfeld et al [23,24] performed an optimization analysis on the net flow of exergy in flat plate collectors for air heating. They found that the collection surface characteristics, especially those of the extended surface, diminished the air flow, thus increasing the net flow of exergy and the thermal efficiency of the device.…”

Section: Introductionmentioning

confidence: 99%

Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates

2010

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Second law optimization of flat-plate solar air heaters Part I: The concept of net exergy flow and the modeling of solar air heaters

Cited by 129 publications

References 10 publications

Experimental Investigation of the Transpired Solar Air Collectors and Metal Corrugated Packing Solar Air Collectors

Experimental Investigation of the Transpired Solar Air Collectors and Metal Corrugated Packing Solar Air Collectors

Energy and Exergy Analysis of a Single-Pass Sequenced Array Baffled Solar Air Heater with Packed Bed Latent Storage Unit for Nocturnal Use

Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates

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