Flow dead zone analysis and structure optimization for the trefoil-baffle heat exchanger

Wang, Ke; Bai, Caipeng; Wang, Yongqing; Min-shan, Liu

doi:10.1016/j.ijthermalsci.2019.02.044

Cited by 22 publications

(9 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The corner whose angle between the wall and the horizontal line is less than 90° is defined as the acute angle corner, like (0, 0) in parallelogram cavity and trapezoid cavity or (0, 2) in the inverted parallelogram cavity and inverted trapezoid cavity. In the acute angle corner, the flow velocity of nanofluids is low, which can be also called flow dead zone 51 . In parallelogram cavity, horizontal cold intrusion flow entered the flow dead zone at a lower speed.…”

Section: Resultsmentioning

confidence: 99%

Lattice Boltzmann simulation on thermal management of electronic components with nonuniform temperature based on nanofluids

Ding

et al. 2021

Int J Energy Res

View full text Add to dashboard Cite

Summary In order to conduct thermal management of electronic components with nonuniform temperature, the flow and heat transfer characteristics of nanofluids in four kinds of cavities with inclined nonuniform heating surfaces were simulated by the lattice Boltzmann model. Classified from the two‐dimensional geometry, the influence of parallelogram cavity, inverted parallelogram cavity, trapezoid cavity, and inverted trapezoid cavity was researched. Considering the complex thermal environment in reality, effects of four kinds of heating wall boundary conditions (constant temperature, gradient temperature, piecewise temperature, and normal temperature) are discussed. Results showed that the flow velocity of nanofluid in the inverted trapezoid cavity is the highest. The highest average Nusselt number near the heating wall of the inverted parallelogram cavity can reach 3.97. Among all kinds of wall heating conditions, cavities with constant temperature have the best heat transfer effect, whose Nu number is 33.4% higher than that of cavities with piecewise temperature in average. The average total entropy change of inverted parallelogram cavity is 16.83. According to the simulation results, the best arrangement of natural convection cooling can be determined.

show abstract

Section: Resultsmentioning

confidence: 99%

Lattice Boltzmann simulation on thermal management of electronic components with nonuniform temperature based on nanofluids

Ding

et al. 2021

Int J Energy Res

View full text Add to dashboard Cite

show abstract

“…In a pressurized water reactor nuclear power plant, heat exchangers with trefoil-hole baffles are the main heat transfer equipment [20]. On the shell side, the tubes are supported by trefoil-hole baffles [6].…”

Section: Introductionmentioning

confidence: 99%

Effect of shell on performance of heat exchanger with trefoil-hole baffle

Wang

Du²,

et al. 2022

THERM SCI

Self Cite

View full text Add to dashboard Cite

The periodic whole cross-section model and the periodic unit duct model were established, and the differences between two models were discussed. The effects of shell wall and baffle edges on the shell side performance of the heat exchanger with trefoil-hole baffle were investigated using both models. Thermodynamics in the shell side and heat transfer coefficient of each tube in different position were discussed. It is found that disparities between the results of the two numerical models decreases with the increase of the inner shell diameter. When the shell diameter is 0.8 m, the disparity is less than 10%, which means that the effects of the shell wall and the edges of baffles become weaker. When the shell diameter is less than 0.8 m, modified correlations for the periodic unit duct model are introduced to quantitatively reveal the effects of shell wall and baffle edges on thermodynamics with the variations of the shell diameter and baffle spacing. The fluid flow velocities at specific locations on the shell side were measured using a Laser Doppler Velocimeter system. The accuracy of the numerical simulation method was verified by the experimental results.

show abstract

“…Many shell-side supporting baffles have been proposed and optimized by researchers around the world to improve the flow characteristics of the flowing medium on the shell side in the hope of obtaining better overall heat exchanger performance (Gu et al 2018a;Wang et al 2019), such as trefoil-hole baffles (You et al 2013), rod baffles (Liu et al 2017;Wang et al 2017), helical baffles (Lei et al 2008), unilateral ladder type helical baffles (Chen et al 2019), ladder-type fold baffles (Wen et al 2015b), flower baffles (You et al 2012), louver baffles (Lei et al 2017), etc. Mellal et al (2017) numerically researched the influence of baffle arrangement on thermal transport in the shell-and-tube heat exchanger with segmental baffles (SG-STHX) and reported that the baffle orientation of 180° and baffle spacing of 64 mm were the optimal design to ensure mixed flow.…”

Section: Introductionmentioning

confidence: 99%

“…The STHX with trefoil-hole baffles is a typical representative of the longitudinal flow heat exchanger, whose shell-side fluid flowing through the trefoil-hole baffles will produce a jet effect. Then, the boundary layer in the heat exchange region is weakened, effectively enhancing heat transfer, but there are some dead zones near the shell wall and baffles (Wang et al 2019). In the STHX with shutter baffles, the shell-side fluid is divided into multiple streams by the shutter baffles and renders them oblique to scour the tube wall, which can significantly reduce the flow dead zone (Gu et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Fluid Flow and Heat Transfer Characteristics Investigation in the Shell Side of the Branch Baffle Heat Exchanger

2021

JAFM

View full text Add to dashboard Cite

The branch baffle heat exchanger, being an improved shell-and-tube heat exchanger, for which the flow manner of the shell-side fluid is a mixed flow of oblique flow and local jet. The computational fluid dynamics (CFD) method has been implemented to investigate the fluid pattern and heat transfer performance. The accuracy of the modeling approach has been confirmed by an experimental approach using a Laser Doppler Velocimeter system. Flow field, temperature field, and pressure field are displayed to study the physics behavior of fluid flow and thermal transport. Heat transfer coefficient, pressure drop, and efficiency evaluation criteria are analyzed. In contrast with the shell-and-tube heat exchanger with segmental baffles and shutter baffles, the pressure loss in the proposed heat exchanger with branch baffles has been dramatically improved, accompanied by a slight decrease in heat transfer coefficient under the same volume flow rate. The efficiency evaluation criteria of the heat exchanger with branch baffles are 28%-31%,13.2%-14.1% higher than those with segmental baffles and shutter baffles, respectively. Further analysis in accordance with the field synergy principle illustrates that the velocity and pressure gradients of the heat exchanger with branch baffle have finer field coordination. The current heat exchanger structure provides a reference for the future optimization design to reach energy saving and emission reduction.

show abstract

Flow dead zone analysis and structure optimization for the trefoil-baffle heat exchanger

Cited by 22 publications

References 33 publications

Lattice Boltzmann simulation on thermal management of electronic components with nonuniform temperature based on nanofluids

Lattice Boltzmann simulation on thermal management of electronic components with nonuniform temperature based on nanofluids

Effect of shell on performance of heat exchanger with trefoil-hole baffle

Fluid Flow and Heat Transfer Characteristics Investigation in the Shell Side of the Branch Baffle Heat Exchanger

Contact Info

Product

Resources

About