Development and validation of Nusselt number and friction factor correlations for laminar flow in semi-circular zigzag channel of printed circuit heat exchanger

Yoon, S. D.; O’Brien, James E.; Chen, Ming‐Hui; Sabharwall, Piyush; Sun, Xiaodong

doi:10.1016/j.applthermaleng.2017.05.135

Cited by 79 publications

(28 citation statements)

References 12 publications

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“…Though the energy dissipation is observed to be higher for this design, there are many advantages and will be discussed in the later section. 5-channel design ▬ Present study, 7-channel design ▬ Present study, 9-channel design ▬ Present study, smooth surface (no threading) ▬ Present study; Zig-Zag (semicircular) ▬ Yoon et al 33 ; Serpentine (square) ▬ Karale et al 34 ; Coiled flow Inverter (circular) ▬ Kumar et al 35 ; Pinched tube (circular) ▬ Hasabnis et al 25 ; Spirally corrugated tube ▬ Kareem et al 44 ; Punched vortex generator ▬ Zhang et al…”

Section: Flow Characterizationmentioning

confidence: 94%

“…The enhancement is observed to be seven times higher than the straight pipe design at Re = 1600. 5-channel design ▬ Present study, 7-channel design ▬ Present study, 9-channel design ▬ Present study, Smooth surface (no threading) ▬ Present study; Zig-Zag (semicircular) ▬ Yoon et al 33 ; Serpentine (square) ▬ Karale et al 34 ; Coiled flow Inverter (circular) ▬ Kumar et al 35 Reynolds number, Re…”

Section: Heat Transfermentioning

confidence: 97%

“…70 It is observed that significant enhancement in the heat transfer is achieved by using inserts compared to other conventional designs (Figure 8b). 25,[33][34][35]44,55,56,70 No significant variation is observed for the different selected threaded designs, except for the inserts without any threading (infinite channels) which exhibits the best performance. All the insert designs have been found to perform better than the straight pipe design with reference to the heat transfer enhancement ratio.…”

Section: Heat Transfermentioning

confidence: 99%

“…Threaded inserts are found to be capable of achieving higher heat transfer when compared to other passive mixers by several folds. 25,[33][34][35]44,55,56,70 Heat transfer enhancement ratio (η), which relates heat transfer and momentum transfer were used to compare the studied configurations and with the literature (Equation 14). The objective functions and constraints used for defining (η) and its significance has been discussed previously in section 3.4.…”

Section: Heat Transfermentioning

confidence: 99%

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Passive Mixer cum Reactor Using Threaded Inserts: Investigations of Flow, Mixing, and Heat Transfer Characteristics

Khalde

Ramanan

Sangwai

et al. 2019

Ind. Eng. Chem. Res.

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Significant efforts have been and are being spent on developing intensified tubular reactors for continuous manufacturing of fine and specialty chemicals. In this work, we have proposed a new design of passive mixer-cum-reactor for process intensification and development of continuous processes. The mixer/reactor consists of threaded inserts with cone-shaped ends, placed concentrically in the tube such that fluid flows through the annular region between the inserts and the tube. The proposed design is easy to fabricate, maintain, and overcomes the limitations of scale up/scale down compared to most of the commercial passive mixers. The split and recombine of flow around inserts, the swirling effect generated by threads, change in the swirl direction due to change in the direction of screw threads, and pinching effect/expansion at the cone-cone shaped ends realize desired enhancements in mixing and heat transfer. A detailed computational study has been carried out on the mixer-cum-reactor to characterize flow, mixing and heat transfer at different operating conditions using a verified and validated CFD model. Various designs and configurations of threaded inserts were considered: 5-channel, 7-channel and 9-channel, smooth surface (no threading) and smooth surface-extended rear end inserts. The flow, mixing and heat transfer were characterized over the Reynolds number range of 100 to 1600. Structure of the generated swirling flow, effect of pinching/expansion, direction reversal of flow, tracer fraction, temperature and path lines were investigated systematically to gain new insights. Threaded inserts could achieve excellent mixing (>99 % of mixing intensity) and heat transfer (7 times smooth inserts and 20 times without inserts). The presented results will provide a sound basis for selecting appropriate threaded inserts for intensifying mixing and heat transfer in tubular reactors. The work also provides a useful starting point for further work on multiphase flows in a tubular reactor with threaded inserts.

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Section: Flow Characterizationmentioning

confidence: 94%

Section: Heat Transfermentioning

confidence: 97%

Section: Heat Transfermentioning

confidence: 99%

Section: Heat Transfermentioning

confidence: 99%

See 2 more Smart Citations

Passive Mixer cum Reactor Using Threaded Inserts: Investigations of Flow, Mixing, and Heat Transfer Characteristics

Khalde

Ramanan

Sangwai

et al. 2019

Ind. Eng. Chem. Res.

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show abstract

“…Kim et al [9] predicted the thermal performance by developing a mathematical expression of geometric parameters, material properties, and flow conditions to express the effectiveness of cross, parallel, and counterflow PCHEs. Yoon et al [10] developed a friction factor and Nusselt number relationship of laminar flow in various bend angles for a semi-circular zigzag channel PCHE. Ishizuk et al [11] studied heat transfer and flow characteristics of zigzag-type PCHE experimentally using supercritical carbon dioxide and obtained the total heat transfer efficiency and pressure drop.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study on Thermal Hydraulic Performance of Supercritical LNG in Zigzag-Type Channel PCHEs

Zhao

Zhou

et al. 2019

Energies

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In this paper, we study a promising plate-type heat exchanger, the printed circuit heat exchanger (PCHE), which has high compactness and is suitable for high-pressure conditions as a vaporizer during vaporization. The thermal hydraulic performance of supercritical produce liquefied natural gas (LNG) in the zigzag channel of PCHE is numerically investigated using the SST κ-ω turbulence model. The thermo-physical properties of supercritical LNG from 6.5 MPa to 10MPa were calculated using piecewise-polynomial approximations of the temperature. The effect of the channel bend angle, mass flux and inlet pressure on local convection heat transfer coefficient, and pressure drop are discussed. The heat transfer and pressure loss performance are evaluated using the Nusselt and Euler numbers. Nu/Eu is proposed to evaluate the comprehensive heat transfer performance of PCHE by considering the heat transfer and pressure drop characteristics to find better bend angle and operating conditions. The supercritical LNG has a better heat transfer performance when bend angle is less than 15° with the mass flux ranging from 207.2 kg/(m2·s) to 621.6 kg/(m2·s), which improves at bend angle of 10° and lower compared to 15° at mass flux above 414.4 kg/(m2·s). The heat transfer performance is better at larger mass flux and lower operating pressures.

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Investigations of mixing and heat transfer in a structured tube‐in‐tube millireactor by numerical, experimental and statistical methods

Liu

Jiang

Wang

et al. 2022

Asia-Pacific J Chem Eng

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Millireactors are widely used in flow chemistry due to their process intensification performance and sufficient product throughout. A novel structured tube‐in‐tube millireactor with industrial potential was designed, whose mixing and heat transfer were investigated by experiment and CFD. Partial least square regression (PLS) was introduced in the flow chemistry study and used to determine that the key parameters of the millireactor were jet Reynolds ( Reh) and hole diameter ()Dh. The introduction of twist tape in the annular space generates swirling flow, which effectively increases the heat transfer capacity (up to 16.5 times). This millireactor achieves excellent mixing (>99% of mixing intensity after 1 cm) and the heat transfer enhancement ratio up to 6.5. The local flow field and concentration field from CFD model agreed with those obtained from PIV and PLIF visualization experiments.

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Development and validation of Nusselt number and friction factor correlations for laminar flow in semi-circular zigzag channel of printed circuit heat exchanger

Cited by 79 publications

References 12 publications

Passive Mixer cum Reactor Using Threaded Inserts: Investigations of Flow, Mixing, and Heat Transfer Characteristics

Passive Mixer cum Reactor Using Threaded Inserts: Investigations of Flow, Mixing, and Heat Transfer Characteristics

Numerical Study on Thermal Hydraulic Performance of Supercritical LNG in Zigzag-Type Channel PCHEs

Investigations of mixing and heat transfer in a structured tube‐in‐tube millireactor by numerical, experimental and statistical methods

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