A comprehensive second law analysis of coil side air injection in the shell and coiled tube heat exchanger: An experimental study

Jafarmadar, Samad; Moosavi, Amin; Dadvand, Abdolrahman; Hashemian, Mehran

doi:10.1016/j.applthermaleng.2018.12.163

Cited by 61 publications

(12 citation statements)

References 24 publications

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“…S gen implies the irreversibility rate in the processes that are divided into two terms, namely, thermal and friction entropy generation, which are illustrated below in Equation (13). The fluid friction terms in the equation for hot and cold streams may be neglected as a result of values fluctuation as two-phase has fluid streams as air bubbles were injected into water [23]; also, their value is very small compared to the thermal entropy generation with a value not exceeding 0.3% [24]. Furthermore, authors are disregarded during their work analysis [25].…”

Section: Discussionmentioning

confidence: 99%

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Combined Energetic and Exergetic Performance Analysis of Air Bubbles Injection into a Plate Heat Exchanger: An Experimental Study

Marouf

Fouad

2023

Energies

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This paper aims to give a comprehensive energetic-exergetic performance analysis on the impacts of injecting-submillimeter of air bubbles into both sides of cold and hot water streams before the entrance port of a corrugated plate heat exchanger (C-PHE) having ten plates within counterflow configuration. Hence, optimize the energy and exergy effectiveness at different operating conditions for counter and parallel fluid flow configurations. Hot streams were studied in seven flow rates ranging from 280 L/h to 880 L/h with a regular step of 100 L/h, and constant hot water temperature and cold-water stream of 50 °C and 290 L/h, respectively. Hence, the air was discharged with four flow rates ranging between 150 and 840 L/h. The obtained results showed the vital role of the ABI technique in enhancing the NTU and effectiveness by 59% and 18.6%, respectively, for CWS. The entropy generation was reduced to 0.038 W/K and the augmentation entropy generation number to 0.087 at the low airflow rate for CWS, which are the main parameters for evaluating the EGM. These two parameters increase the Witte-Shamsundar-efficiency to a maximum value of 98.6% at the same operating conditions. Moreover, the exergy effectiveness was enhanced to a maximum value of 80.9% at a high ABI flow rate and low volumetric rate of the hot stream at CWS. The thermo-economic assessment has been carried out, which revelers the positive effects of ABI on the combined energetic and exergetic performance on both sides, i.e., hot and cold sides.

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Section: Discussionmentioning

confidence: 99%

“…Overall heat transfer coefficient uncertainty ω U can be obtained from Equation ( 22) and derived from (23) to (25).…”

Section: Uncertainty Analysismentioning

confidence: 99%

Combined Energetic and Exergetic Performance Analysis of Air Bubbles Injection into a Plate Heat Exchanger: An Experimental Study

Marouf

Fouad

2023

Energies

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“…Figure 1 presents the schematic of the test rig provided for caring out the considered tests. The air injection method utilized in this study was previously used by different researchers [5,21,22]. The advantage of this injection method is that since it is located outside the heat exchange unit, it could be utilized for the existing thermal systems in industrial applications.…”

Section: Experimental Methodology and Proceduresmentioning

confidence: 99%

“…This is since the mass flow rate and the Cp of the air flow rate are significantly less than the water flow rate. It should be noted that many experts [27][28][29][30] have stated that this effect is negligible. Through the present investigation, the maximum fraction between the air mass flow rate and water mass flow rates was 0.0053 which denotes that the total energy gained by the air stream is so less than that of the water stream.…”

Section: Parameter Definitionmentioning

confidence: 99%

Fouling Performance of A Horizontal Corrugated Tube due to Air Injection

2022

IJE

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In the present study, the fouling performance of a circumferentially corrugated tube was probed due to the air injection. The molasses of sugar beet was considered as the working fluid. The tube was considered to be under constant heat flux. Also, the flow rate of the molasses of sugar beet was considered to be constant. Five different flow rates of the airstream were considered to check the effect of airflow rate. The flow rate of working fluid was kept at the constant flow rate of 2 L/min. The tests were conducted for 5000s (84 minutes). For a better understanding of the nature of the flow, the structure of two-phase steam was recorded via a Canon SX540 Camera. The results presented that the air injection in the corrugated tube will completely change the structure of the working fluid which will bring a very turbulent structure for the working fluid. The thermal results presented that during the testing time, the air injection will keep the heat transfer coefficient about 120% higher than a single-phase stream. The mass evaluation results revealed that the air injection could decrease the weight of fouled substance up to 75%.

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“…The experimental unit operates in such a way that the movement of the piston (16) in the engine cylinder (19) creates negative pressure in the following parts of the supply system: the air filter (9), the carburettor (8), the HEX air-fuel mixture channel (14), the inlet manifold (15), and the engine cylinder (19). Under negative pressure the fuel is sucked in from the carburettor's (8) float chamber (11), through the nozzle (12), and into the carburettor throat (10), and an air-fuel mixture is formed. The carburised air-fuel mixture then moves to the HEX's (13) air-fuel mixture channel (14), in which the air-fuel mixture will be complementary mixed and heated.…”

Section: Methodsmentioning

confidence: 99%

Developing and testing air-fuel mixture heating system for internal combustion engine

Raide

Ilves

Olt

2021

20th International Scientific Conference Engineering for Rural Development Proceedings

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An internal combustion engine consumes a maximum of a quarter of the energy that is fed into it in the form of fuel. Most of the useful energy leaves the engine in the form of heat energy, specifically as exhaust gases. In addition, exhaust gases contain a number of harmful components, which can be significantly reduced by improving the efficiency of the combustion process. The aim of this article is, firstly, to provide an overview of the design and development of a heat exchanger, one which uses exhaust gas energy to heat the air-fuel mixture and which is installed into the fuel supply system; and secondly, to analyse the impact of the pre-heated air-fuel mixture on the test engine's output parameters. The improved fuel supply system allows for the more efficient mixing and heating of the air-fuel mixture. Heating the air-fuel mixture allows light and heavy fuels to be used in a spark ignition engine. Additional mixing and heating of the air-fuel mixture ensures a faster and more complete combustion process in the engine cylinder. The present study compares the efficacy and economical parameters of a small displacement, four-stroke, spark ignition engine, which is equipped with an advanced fuel system. Experiments were carried out using standard petrol, ethanol, and diesel fuels. Data gained from this experiment have been compared and presented. The results show that further mixing and heating of the fuel mixture makes it possible to use different fuels in a spark ignition engine, while also significantly reducing fuel consumption levels and the volume of harmful components in exhaust gases (such as CO, HC, CO2 and soot).

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A comprehensive second law analysis of coil side air injection in the shell and coiled tube heat exchanger: An experimental study

Cited by 61 publications

References 24 publications

Combined Energetic and Exergetic Performance Analysis of Air Bubbles Injection into a Plate Heat Exchanger: An Experimental Study

Combined Energetic and Exergetic Performance Analysis of Air Bubbles Injection into a Plate Heat Exchanger: An Experimental Study

Fouling Performance of A Horizontal Corrugated Tube due to Air Injection

Developing and testing air-fuel mixture heating system for internal combustion engine

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