Second law efficiency analysis of air injection into inner tube of double tube heat exchanger

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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“…Witte-Shamsundar efficiency (η W−S ), is an important principle for evaluating the combined energetic and exergetic performance of HEs [27,28]…”

Section: Discussionmentioning

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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“…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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“…2021 (Sinaga et al) [8] The effect of two-phase air/water flows on the thermally efficiency of a vertical twin pipe heat exchanger was investigated in this work. Inside a dual pipe heat exchanger, the air flows were combined in a T junction before being pumped into the heating exchanger's inner tube.…”

Section: (Singh and Sarkar)mentioning

confidence: 99%

Review on Heat Exchangers with Different Geometries and Flow Arrangement

Gautam¹,

Sagar²

2022

IJOSCIENCE

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A heat exchanger is a device that enables heat from one fluid (liquid or gas) to be transferred to some other fluid (liquid or gas) without the two fluids mixing or coming into direct contact. The various sorts of fluid flows in different types of heat exchanging systems are discussed in this paper.Heat exchangers can be found in a variety of locations, generally working to warm up or cool buildings or to improve the efficiency of engines and machineries. Refrigerators and air conditioners, for example, use heat exchangers in the opposite way that central heating systems do: they remove heat from a chamber or room that isn't needed and pump it away in a fluid to another location that can be dropped out of the way. The refrigerating fluid is completely enclosed within a series of channels, so it never comes into direct contact with the air: it extracts heat energy from the air inside and dumps it in the air outside, but it never mixes with it.

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Second law efficiency analysis of air injection into inner tube of double tube heat exchanger

Cited by 45 publications

References 30 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

Review on Heat Exchangers with Different Geometries and Flow Arrangement

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