Numerical Study on Flow and Heat Transfer Performance of Natural Gas in a Printed Circuit Heat Exchanger During Trans-Critical Liquefaction

2020 ◽  
Author(s):  
Ting Ma ◽  
Pan Zhang ◽  
Jie Lian ◽  
Hanbing Ke ◽  
Wei Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Natural Gas ◽  
Numerical Study ◽  
Local Pressure ◽  
Local Flow ◽  
Printed Circuit ◽  
Minimum Value ◽  
Flow And Heat Transfer

Abstract The main cryogenic heat exchanger is a core piece of equipment in the liquefaction of natural gas. The printed circuit heat exchanger is gradually becoming a primary choice for the main cryogenic heat exchanger, because it has good pressure resistance, high efficiency, and compactness. In this work, a numerical simulation is conducted to examine the local flow and heat transfer characteristics of natural gas in the printed circuit heat exchanger during trans-critical liquefaction. It is found that the heat flux density reaches a minimum value and the heat transfer is the worst when the temperature difference between the hot and cold sides is the smallest. Owing to the large variations in physical properties of trans-critical natural gas, the local pressure drop exhibits an upward parabolic shape along the flow direction, and the pressure drop reaches a minimum value near the pseudo-critical point. Finally, the friction factor and heat transfer correlations for natural gas during trans-critical liquefaction are fitted.

Numerical Study of Flow and Heat Transfer of Heat Exchanger with Louver Baffles

2014 ◽  
Vol 721 ◽  
pp. 174-177 ◽  
Author(s):  
Hui Lai
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Energy Savings ◽  
Numerical Study ◽  
Dead Zone ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Local Flow ◽  
Flow And Heat Transfer

This paper presents a heat exchanger of louver baffle, the establishment of a three-dimensional model, research by numerical simulation of flow and heat transfer performance of the heat exchanger baffles different louver angle, and analyzes its local temperature, and evaluated for its overall performance. The results show that louver baffle heat exchanger avoids the existence of traditional segmental baffle heat exchanger problem after baffle local flow dead zone; compared with conventional segmental baffle heat exchanger, louver baffle heat exchanger greatly reduces the heat exchanger shell side pressure drop; louver baffle heat exchanger in the unit pressure drop coefficients are higher than the segmental baffle heat exchanger, and with the baffle plate angle increases, with significant energy savings.

scholarly journals Numerical Study on Flow and Heat Transfer Characteristics of Trapezoidal Printed Circuit Heat Exchanger

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1589
Author(s):  
Yuxuan Ji ◽  
Kaixiang Xing ◽  
Kefa Cen ◽  
Mingjiang Ni ◽  
Haoran Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Numerical Study ◽  
Three Dimensional ◽  
Channel Structure ◽  
Complex Flow ◽  
Compact Structure ◽  
Printed Circuit ◽  
Flow And Heat Transfer

Printed circuit heat exchanger (PCHE) is a promising regenerative device in the sCO2 power cycle, with the advantages of a large specific surface area and compact structure. Its tiny and complex flow channel structure brings enhanced heat transfer performance, while increasing pressure drop losses. It is, thus, important to balance heat transfer and flow resistance performances with the consideration of sCO2 as the working agent. Herein, three-dimensional models are built with a full consideration of fluid flow and heat transfer fields. A trapezoidal channel is developed and its thermal–hydraulic performances are compared with the straight, the S-shape, and the zigzag structures. Nusselt numbers and the Fanning friction factors are analyzed with respect to the changes in Reynolds numbers and structure geometric parameters. A sandwiched structure that couples two hot channels with one cold channel is further designed to match the heat transfer capacity and the velocity of sCO2 flows between different sides. Through this novel design, we can reduce the pressure drop by 75% and increase the regenerative efficiency by 5%. This work can serve as a solid reference for the design and applications of PCHEs.

scholarly journals Numerical Investigation on Flow and Heat Transfer Characteristics of Supercritical Liquefied Natural Gas in an Airfoil Fin Printed Circuit Heat Exchanger

2017 ◽  
Author(s):  
Zhongchao Zhao ◽  
Kai Zhao ◽  
Dandan Jia ◽  
Pengpeng Jiang ◽  
Rendong Shen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Natural Gas ◽  
Hydraulic Performance ◽  
Liquefied Natural Gas ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Printed Circuit ◽  
Flow And Heat Transfer ◽  
Staggered Arrangement

As a new kind of highly compact and efficient micro-channel heat exchanger, printed circuit heat exchanger (PCHE) is a promising candidate satisfying the heat exchange requirements of liquefied natural gas (LNG) vaporization at low and high pressure. The effects of airfoil fin arrangement on heat transfer an flow resistance were numerically investigated using supercritical liquefied natural gas (LNG) as a working fluid. The thermal properties of supercritical LNG were tested by utilizing a REFPROF software database. Numerical simulation was performed using FLUENT. The inlet temperature of supercritical LNG was 121 K,and its pressure was 10.5MPa. The reference mass flow rate of LNG was set 1.22 g/s for the vertical pitch Lv = 1.67 mm and the staggered pitch Ls = 0 mm, with the Reynolds number of about 3750. The SST k-ω model with enhanced wall treatment was selected by comparing with the experimental data. The airfoil fin PCHE had better thermal-hydraulic performance than that of the straight channel PCHE. Moreover, the airfoil fins with staggered arrangement displayed better thermal performance than that of the fins with parallel arrangement. The thermal-hydraulic performance of airfoil fin PCHE was improved with increasing Ls and Lv. Moreover, Lv  affected on the Nusselt number and pressure drop of airfoil fin PCHE more obviously. In conclusion, a sparser staggered arrangement of fins showed a better thermal-hydraulic performance in airfoil fin PCHE.

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