Numerical analysis on pressure drop and heat transfer performance of mesh regenerators used in cryocoolers

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

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A Study on Flow Boiling in Microchannel With Piranha Pin Fin

Volume 3: Advanced Fabrication and Manufacturing; Emerging Technology Frontiers; Energy, Health and Water- Applications of Nano-, Micro- and Mini-Scale Devices; MEMS and NEMS; Technology Update Talks; Thermal Management Using Micro Channels, Jets, Sprays ◽

10.1115/ipack2015-48103 ◽

2015 ◽

Cited By ~ 2

Author(s):

X. Yu ◽

C. Woodcock ◽

Y. Wang ◽

J. Plawsky ◽

Y. Peles

Keyword(s):

Heat Transfer ◽

Heat Flux ◽

Fluid Flow ◽

Pressure Drop ◽

Heat Transfer Performance ◽

Flow Boiling ◽

Transfer Performance ◽

Flow Conditions ◽

Pin Fin ◽

Flow And Heat Transfer

In this paper we reported an advanced structure, the Piranha Pin Fin (PPF), for microchannel flow boiling. Fluid flow and heat transfer performance were evaluated in detail with HFE7000 as working fluid. Surface temperature, pressure drop, heat transfer coefficient and critical heat flux (CHF) were experimentally obtained and discussed. Furthermore, microchannels with different PPF geometrical configurations were investigated. At the same time, tests for different flow conditions were conducted and analyzed. It turned out that microchannel with PPF can realize high-heat flux dissipation with reasonable pressure drop. Both flow conditions and PPF configuration played important roles for both fluid flow and heat transfer performance. This study provided useful reference for further PPF design in microchannel for flow boiling.

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Numerical analysis on heat transfer performance of oscillating flow in wavy channel

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2021.107279 ◽

2022 ◽

Vol 172 ◽

pp. 107279

Author(s):

Ge-Yu Zhong ◽

Peng-Fan Chen ◽

Fa-Zhu Liu ◽

Ying-Wen Liu

Keyword(s):

Heat Transfer ◽

Numerical Analysis ◽

Heat Transfer Performance ◽

Oscillating Flow ◽

Transfer Performance ◽

Wavy Channel

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An experimental study on heat transfer performance and pressure drop of nanofluids using graphene and multi-walled carbon nanotubes based on diesel oil

Powder Technology ◽

10.1016/j.powtec.2019.04.078 ◽

2019 ◽

Vol 352 ◽

pp. 369-380 ◽

Cited By ~ 12

Author(s):

Atiyeh Naddaf ◽

Saeed Zeinali Heris ◽

Babak Pouladi

Keyword(s):

Heat Transfer ◽

Carbon Nanotubes ◽

Experimental Study ◽

Pressure Drop ◽

Heat Transfer Performance ◽

Diesel Oil ◽

Transfer Performance ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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3D Printed Architected Heat Sinks Cooling Performance in Free and Forced Convection Environments

ASME 2020 Heat Transfer Summer Conference ◽

10.1115/ht2020-9067 ◽

2020 ◽

Author(s):

Mohamed I. Hassan Ali ◽

Oraib Al-Ketan ◽

Mohamad Khalil ◽

Nada Baobaid ◽

Kamran Khan ◽

...

Keyword(s):

Heat Transfer ◽

Pressure Drop ◽

Forced Convection ◽

Heat Transfer Performance ◽

Convection Heat Transfer ◽

Heat Sinks ◽

Cfd Modeling ◽

Transfer Performance ◽

Convection Heat ◽

Performance Study

Abstract In this work, we extend our heat transfer performance study on our proposed new and novel 3D printable architected heat sinks with geometrically complex structures based on triply periodic minimal surfaces (TPMS). Computational fluid dynamics (CFD) modeling is used to assess the effect of porosity distribution, heat load, and isothermal boundary condition on the performance of the proposed TPMS-based heat sinks in active cooling using natural and forced convection heat transfer environments. The convection heat transfer coefficient, surface temperature, pressure drop are predicted using CFD method. The CFD model is validated using experimental results for the pressure drop and is verified by standard analytical results. Three TPMS structures are investigated in different orientations. Dimensionless heat transfer groups are developed to globalize the heat transfer performance of the proposed heat sinks.

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Experimental and Simulation Study of Micro-Channel Backplane Heat Pipe Air Conditioning System in Data Center

Applied Sciences ◽

10.3390/app10041255 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1255

Author(s):

Liping Zeng ◽

Xing Liu ◽

Quan Zhang ◽

Jun Yi ◽

Xiaohua Li ◽

...

Keyword(s):

Heat Transfer ◽

Heat Transfer Coefficient ◽

Pressure Drop ◽

Transfer Coefficient ◽

Heat Transfer Performance ◽

Outlet Temperature ◽

Transfer Performance ◽

Micro Channel ◽

Heat Transfer Capacity ◽

The Heat Transfer Coefficient

This paper mainly studies the heat transfer performance of backplane micro-channel heat pipes by establishing a steady-state numerical model. Compared with the experimental data, the heat transfer characteristics under different structure parameters and operating parameters were studied, and the change of heat transfer coefficient inside the system, the air outlet temperature of the back plate and the influence of different environmental factors on the heat transfer performance of the system were analyzed. The results show that the overall error between simulation results and experimental data is less than 10%. In the range of the optimal filling rate (FR = 64.40%–73.60%), the outlet temperature at the lowest point and the highest point of the evaporation section is 22.46 °C and 19.60 °C, the temperature difference does not exceed 3 °C, and the distribution gradient in vertical height is small and the air outlet temperature is uniform. The heat transfer coefficient between the evaporator and the condenser is larger than the heat transfer coefficient under the conditions of low and high liquid charge rate. It increases gradually along the flow direction, and decreases gradually with the flow rate of the condenser. When the width of the flat tube of the evaporator increases from 20 mm to 28 mm, the internal pressure drop of the evaporator decreases by 45.83% and the heat exchange increases by 18.34%. When the number of evaporator slices increases from 16 to 24, the heat transfer increases first and then decreases, with an overall decrease of 2.86% and an increase of 87.67% in the internal pressure drop of the evaporator. The inclination angle of the corrugation changes from 30° to 60°, and the heat transfer capacity and pressure drop increase. After the inclination angle is greater than 60°, the heat transfer capacity and resistance decrease. The results are of great significance to system optimization design and engineering practical application.

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