Heat transfer analysis on dimple geometries and arrangements in dimple jacketed heat exchanger

Qian, Jin-yuan; Wu, Zan; Zhang, Qiankun; Sundén, Bengt

doi:10.1108/hff-12-2018-0792

Cited by 8 publications

(6 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sound traveling in gases is approximately an adiabatic process, and the local sound speed, which can be determined by Eq. (11), is related to the gas properties.…”

Section: Adiabatic Venturi Tube Wallmentioning

confidence: 99%

“…However, the temperature of the superheated steam leaving the pressure reducing valve should be reduced. In order to augment the heat transfer efficiency, scholars have proposed many novel high-efficiency heat transfer devices like spirally corrugated tube [6][7][8], dimpled surfaces [9][10][11], and inserted tubes/microtubes [12,13]. Furthermore, many investigators aimed at conducting research on the cooling of superheated steam.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A numerical study of heat transfer effects and aerodynamic noise reduction in superheated steam flow passing a temperature and pressure regulation valve

Qian

Chen

Jin

et al. 2020

Numerical Heat Transfer, Part A: Applications

Self Cite

View full text Add to dashboard Cite

Steam is a common medium in thermal engineering. When it flows through a throttling element, the aerodynamic noise may occur due to the disturbance. In this investigation, superheated steam flowing through a Venturi tube, one of the main parts in a temperature and pressure regulation valve, at different thermal conditions is studied to analyze to effects of heat transfer on the acoustic power. With a high temperature and a low pressure, the superheated steam is treated as ideal gas. The flow velocity is high, so the k-epsilon turbulent model is used, with the compressible steam. The results show that under the adiabatic condition, the acoustic power mainly influenced by the turbulent characteristics, such as the dissipation rate and the turbulent kinetic energy. Comparing the acoustic power levels at different thermal conditions, it is found that a lower temperature results to a lower acoustic power.

show abstract

“…The sound traveling in gases is approximately an adiabatic process, and the local sound speed, which can be determined by Eq. (11), is related to the gas properties.…”

Section: Adiabatic Venturi Tube Wallmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A numerical study of heat transfer effects and aerodynamic noise reduction in superheated steam flow passing a temperature and pressure regulation valve

Qian

Chen

Jin

et al. 2020

Numerical Heat Transfer, Part A: Applications

Self Cite

View full text Add to dashboard Cite

show abstract

“…Heat exchangers can be classified into several groups according to geometric configuration, although improving the heat transfer performance is the common goal. Over the last 50 years, the single-phase pipe exchanger has seen a variety of augmentation techniques, and the heat transfer capacity has been improved greatly [1][2][3][4][5][6][7][8]. Among various studies carried out on pipe flow enhanced technologies, adopting the insert inside a tube is a common approach.…”

Section: Introductionmentioning

confidence: 99%

Internal Flow Analysis of a Heat Transfer Enhanced Tube with a Segmented Twisted Tape Insert

et al. 2020

Self Cite

View full text Add to dashboard Cite

A heat exchanger is a device that transfers unneeded heat from one region to another, and transferred heat may be fully reused, thus improving energy efficiency. To augment this positive process, many studies and investigations on automation technologies have been performed. Inserts are widely used in pipe flow for heat transfer enhancement, since they can break the boundary layer and promote the heat exchange. Segmented twisted tape, which is applicable in 3D printing, is a novel insert and has potential in heat transfer enhancement. To clarify its advantages and disadvantages, this research presents a numerical investigation of vortex flow and heat enhancement in pipes containing one segmented twisted element. Flow state and heat transfer behaviour are obtained by simulation under constant wall temperature with different Reynolds numbers, ranging from 10,000 to 35,000. The effects of geometric parameters, including twist ratio (P/D = 2.0, 3.3 and 4.6) and length ratio (L/P = 0.3, 0.5 and 0.7), on the Nusselt number (Nu) and friction factor (f) are investigated. Streamline and temperature distribution are presented. Meanwhile, local and overall heat transfer performance is compared with those of a smooth tube, and the overall performance is evaluated by performance evaluation factor (η). The results indicate that the twist ratio (P/D) plays a dominant role in heat transfer enhancement while the length ratio (L/P) also has considerable influence. It is shown that a segmented tape insert can increase the overall heat transfer rate by 23.5% and the friction factor by 235%, while local improvement along the tube can be 2.8 times more than the plain tube.

show abstract

“…Among all rib geometries, the round transition cylindrical ribs gave the highest heat transfer. Qian et al (2019) analyzed different geometries and triangular and rectangular arrangement of dimples improving heat transfer performance of jacketed heat exchanger. They obtained better heat transfer and uniformity compared to conventional jacketed exchanger.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulations and optimization of impinging jet configuration

Singh

Balaji

Prasad

2020

HFF

View full text Add to dashboard Cite

Purpose Numerical simulations are performed to determine the heat transfer characteristics of slot jet impingement of air on a concave surface. The purpose of this paper is to investigate the effect of protrusions on the heat transfer by placing semi-circular protrusions on the concave surface at several positions. After identifying appropriate locations where the heat transfer is a maximum, multiple protrusions are placed at desired locations on the plate. The gap ratio, curvature ratio (d/D) and the dimensions of the plate are varied so as to obtain heat transfer data. The curvature ratio is varied first, keeping the concave diameter (D) fixed followed by a fixed slot width (d). A surrogate model based on an artificial neural network is developed to determine optimum locations of the protrusions that maximize the heat transfer from the concave surface. Design/methodology/approach The scope and objectives of the present study are two-dimensional numerical simulations of the problem by considering all the geometrical parameters (H/d, dp, Re, θ) affecting heat transfer characteristics with the help of networking tool and numerical simulation. Development of a surrogate forward model with artificial neural networks (ANNs) with a view to explore the full parametric space. To quantitatively ascertain if protrusions hurt or help heat transfer for an impinging jet on a concave surface. Determination of the location of protrusions where higher heat transfer could be achieved by using exhaustive search with the surrogate model to replace the time consuming forward model. Findings A single protrusion has nearly no effect on the heat transfer. For a fixed diameter of concave surface, a smaller jet possesses high turbulence kinetic energy with greater heat transfer. ANN is a powerful tool to not only predict impingement heat transfer characteristics by considering multiple parameters but also to determine the optimum configuration from many thousands of candidate solutions. A maximum increase of 8 per cent in the heat transfer is obtained by the best configuration constituting of multiple protrusions, with respect to the baseline smooth configuration. Even this can be considered as marginal and so it can be concluded that first cut results for heat transfer for an impinging jet on a concave surface with protrusions can be obtained by geometrically modeling a much simpler plain concave surface without any significant loss of accuracy. Originality/value The heat transfer during impingement cooling depends on various geometrical parameters but, not all the pertinent parameters have been varied comprehensively in previous studies. It is known that a rough surface may improve or degrade the amount of heat transfer depending on their geometrical dimensions of the target and the rough geometry and the flow conditions. Furthermore, to the best of authors’ knowledge, scarce studies are available with inclusion of protrusions over a concave surface. The present study is devoted to development of a surrogate forward model with ANNs with a view to explore the full parametric space.

show abstract

Heat transfer analysis on dimple geometries and arrangements in dimple jacketed heat exchanger

Cited by 8 publications

References 50 publications

A numerical study of heat transfer effects and aerodynamic noise reduction in superheated steam flow passing a temperature and pressure regulation valve

A numerical study of heat transfer effects and aerodynamic noise reduction in superheated steam flow passing a temperature and pressure regulation valve

Internal Flow Analysis of a Heat Transfer Enhanced Tube with a Segmented Twisted Tape Insert

Numerical simulations and optimization of impinging jet configuration

Contact Info

Product

Resources

About