Analytical predictions of exergoeconomic performance of a solar air heater with surface roughness of metal waste

Phu, Nguyen Minh; Bao, Tran The; Hung, Hoang Nam; Ngo, Tu Thien; Hap, Nguyen Van

doi:10.1007/s10973-020-09787-5

Cited by 23 publications

(13 citation statements)

References 67 publications

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“…Verifications have been performed about heat transfer and hydraulics of single-pass and multipass SAHs. Confirmation on the prediction of the exergy analysis model was presented in our previous study [5]. It is not repeated here for the sake of brevity.…”

Section: Preference Selection Index Methods For Multiobjectivesupporting

confidence: 67%

“…Modelling. e input exergy of the SAH is constituted by the air inflow and solar radiation source as follows [5,38]:…”

Section: Exergy-basedmentioning

confidence: 99%

“…Facing the needs and limitations of SAH, research on improving SAH performance is always paid attention [4]. Heat transfer improvement between the absorber plate and the air in the collector can be mentioned as the insertion of vortex generators [5], inclined plates [6], or roughness ribs on the absorber surface [7] to diminish the viscous sublayer close to the surface and create mixing of the primary and secondary flows.…”

Section: Introductionmentioning

confidence: 99%

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First and Second Law Evaluation of Multipass Flat-Plate Solar Air Collector and Optimization Using Preference Selection Index Method

Luân

Phu

2021

Mathematical Problems in Engineering

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In this paper, different flow configurations of multipass flat-plate air collectors are explored. Multiple passes are formed from glass cover, absorber plate, and back plate. Five types of air collectors were analysed and optimized with respect to maximum efficiencies and minimum cost. The analytical prediction of the heat exchanger, pressure loss, and efficiencies was presented. The effects of mass flow rate from 0.01 to 0.02 kg/s, air channel depth from 15 to 30 mm, and collector length from 1.5 to 2.5 m on different configurations were examined and compared. The results of the parametric study show that the triple-pass type has the greatest efficiency, whereas the smallest efficiency is of the single-pass type. Among double-pass types, the type with two glass covers and natural convection heat transfer achieved the highest effective and exergy efficiencies due to a reduction in the top loss. Double-pass type with single glass cover is not recommended from both energy and exergy standpoints. As the collector length increases, the effective efficiency decreases, but the exergy efficiency increases. The exergy performance of the triple-pass type can reach up to 5% at the air flow rate of 0.005 kg/s. Finally, multiobjective optimization using the preference selection index method is conducted with three targets including effective efficiency, exergy efficiency, and number of plates. Optimal results show that the triple-pass type with the lowest air flow rate and the longest length is the best. The effective and exergy efficiencies for the best case were found to be about 52.1% and 4.7%, respectively. However, this type with the highest flow rate and the shortest length is the worst.

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Section: Preference Selection Index Methods For Multiobjectivesupporting

confidence: 67%

“…Modelling. e input exergy of the SAH is constituted by the air inflow and solar radiation source as follows [5,38]:…”

Section: Exergy-basedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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First and Second Law Evaluation of Multipass Flat-Plate Solar Air Collector and Optimization Using Preference Selection Index Method

Luân

Phu

2021

Mathematical Problems in Engineering

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“…The repeated heat transfer element in the form of semicircular wire loops is expected to act as the artificial roughness near to absorber plate and turbulators across the collector cross section. Moreover, it was seen in literature that during the simulation of flat plate solar collector, an essential heat transfer parameter, i.e., radiative heat transfer, is often ignored and studies are limited to 1D and 2D analysis [31][32][33][34]. In the present analysis, more reliable and realistic 3D numerical models considering the radiative, convective and conductive heat transfer inside the flat plate solar collector were developed and model predicted results were validated with experiments.…”

Section: Introductionmentioning

confidence: 95%

Heat transfer augmentation of flat plate solar collector through finite element-based parametric study

Rani

Tripathy

2020

J Therm Anal Calorim

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The introduction of fins and baffles on the absorber plate is an effective way to ameliorate the thermal performance of flat plate solar collector (FPSC), but obstructs the air passage leading to considerable pumping power penalty. In the current work, attempt is made to improve the overall performance of collector with the incorporation of hollow semicircular loop fins and rectangular baffles over the absorber plate for air mass flow rate ranging from 0.006 to 0.02 kg s −1 . A parametric study was carried out with finite element approach considering different radius (2-4 cm), pitch (6-20 cm) and number of semicircular loops per row in transverse direction (3-8 loops). Compared to intermittent loops, placement of continuous staggered semicircular loops was more effective for attaining uniform profile and higher magnitude of air temperature at collector outlet. With regard to FPSC, finned collector provided 2.64-2.95 times greater Nusselt number and 41-75% higher thermal efficiency, as well as exhibited 8.38-10.4 K higher collector outlet average air temperature. The pressure drop noted for FPSC was 0.14 Pa and increased to the range of 0.5-0.7 Pa with the addition of loops and baffles at an air mass flow rate of 0.01 kg s −1 . Collector having baffles and continuous semicircular loops of radius 3 cm, made up of 2-mm-thick wire, presented maximum thermohydraulic performance factor of 1.73 in conjunction with showing maximum magnitude and uniform profile of collector outlet temperature. The modified collector with semicircular loops along with baffles will find its application in efficient drying of agricultural commodities.

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“…The equations below present a model for calculating SAH's performance such as thermal efficiency, effective efficiency and exergy efficiency. This model has been adopted by many researchers in the exergy study of SAH [7,9,12,14,16,18,20,22,23,25,27]. The useful heat gain of air flow acquired from solar radiation can be calculated by the following equations…”

Section: Efficiencies Of Roughened Solar Air Heater 31 Thermal Efficmentioning

confidence: 99%

A Review of Energy and Exergy Analyses of a Roughened Solar Air Heater

Phu

Luân

2020

ARFMTS

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In this paper, eleven roughness elements in solar air heater duct analysed both energy and exergy were reviewed. Various roughness geometries such as ribs, twisted tap, baffles, and metal waste were surveyed about heat transfer and friction when the air flow is passing absorber plate. Evaluation criteria of roughness on the absorber plate including thermohydraulic performance parameter, thermal efficiency, effective efficiency, and exergy efficiency were presented and compared. Results showed that protruded ribs in arc shape indicated the largest Nusselt number. The ribs exhibited the highest thermohydraulic performance parameter at a Reynolds number greater than 5000. Jet impingement with arc-shaped ribs and roughness elements of metal waste were found the smallest exergy efficiencies. The biggest effective and exergy efficiencies were obtained to be 70% and 1.9%, respectively. The thermohydraulic performance parameter varied from 0.5 to 2.0. The review paper aims to provide information about roughness geometries investigated both first and second laws of thermodynamics and figure of merits to overview artificial roughness in a solar air heater.

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Analytical predictions of exergoeconomic performance of a solar air heater with surface roughness of metal waste

Cited by 23 publications

References 67 publications

First and Second Law Evaluation of Multipass Flat-Plate Solar Air Collector and Optimization Using Preference Selection Index Method

First and Second Law Evaluation of Multipass Flat-Plate Solar Air Collector and Optimization Using Preference Selection Index Method

Heat transfer augmentation of flat plate solar collector through finite element-based parametric study

A Review of Energy and Exergy Analyses of a Roughened Solar Air Heater

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