Polymeric Hollow Fiber Heat Exchangers:  An Alternative for Lower Temperature Applications

2004 ◽  
Vol 43 (25) ◽  
pp. 8093-8106 ◽  
Author(s):  
Dimitrios M. Zarkadas ◽  
Kamalesh K. Sirkar
Keyword(s):  
Hollow Fiber ◽  
Heat Exchangers ◽  
Lower Temperature ◽  
Temperature Applications

Polymeric hollow fiber heat exchangers

2019 ◽  
Author(s):  
Miroslav Raudenský
Keyword(s):  
Hollow Fiber ◽  
Heat Exchangers

Polymeric Hollow-Fiber Bundles as Immersed Heat Exchangers

2018 ◽  
Vol 41 (7) ◽  
pp. 1457-1465 ◽  
Author(s):  
Klarissa Weiß ◽  
Ilya Astrouski ◽  
Marcus Reppich ◽  
Miroslav Raudenský
Keyword(s):  
Hollow Fiber ◽  
Heat Exchangers ◽  
Fiber Bundles

Numerical Investigation of a Friction Ventilator for Different Geometrical Setups

2016 ◽  
Vol 19 ◽  
pp. 35-42 ◽  
Author(s):  
Julian Praß ◽  
Andreas Renz ◽  
Johannes Weber ◽  
Stefan Becker ◽  
Jörg Franke
Keyword(s):  
Heat Exchangers ◽  
Heat Recovery ◽  
Ventilation System ◽  
Pressure Jump ◽  
Noise Generation ◽  
Temperature Level ◽  
Pressure Losses ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Novel Concept

Conventional ventilation systems with heat recovery used for building aeration exhibit characteristic disadvantages arising from their operating principle such as noise generation from bladed ventilators or remarkable pressure losses generated by heat exchangers. A novel concept that combines ventilators and heat exchanger in one compact friction ventilator that rotates in two separated ducts producing two opposed airflows and transferring thermal energy from the higher temperature airflow to the lower temperature level can overcome the mentioned shortcomings. In order to demonstrate the feasibility of a friction ventilator to operate as ventilation system with heat recovery computational fluid dynamics were used to analyze the resulting pressure jump and volume flow for different geometrical setups. An extensive grid dependency study for a defined operating point that represents the typical use has been carried out in order to improve the numerical results. Furthermore, the results were compared to experimental data whenever possible.

Dynamic Recrystallization Behaviour in Cu-Sn-P Alloy for High Strength Copper Tube

2010 ◽  
Vol 654-656 ◽  
pp. 1271-1274 ◽  
Author(s):  
Masato Watanabe ◽  
Takashi Shirai ◽  
Akihiko Ishibashi ◽  
Hiromi Miura
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Heat Exchangers ◽  
High Strength ◽  
Strain Rates ◽  
Testing Conditions ◽  
Lower Temperature ◽  
Increasing Temperature ◽  
Different Content

Dynamic recrystallization (DRX) behaviour in a newly developed Cu-Sn-P alloy for heat exchangers and tubes was systematically investigated. For this purpose, Cu-Sn-P alloys with different content of Sn were deformed in compression at temperatures between 1073 K and 1213 K and at various strain rates from 2 x 10-4 s-1 to 2 x 10-1 s-1. The onset of DRX was more advanced with increasing temperature and with decreasing strain rate. Full DRX was not achieved at the testing conditions of lower temperature and higher strain rate even after straining to ε = 1.0. This tendency was more significant in the alloy with higher Sn content. With increasing Sn content, the flow stress and the obtained grains size became higher and finer, respectively. These experimental results indicate the important role of Sn for strengthening and microstructual control.

scholarly journals Crude Oil Fouling in Heat Exchangers: A Study on Effects of Influencing Forces

2021 ◽  
Vol 287 ◽  
pp. 03003
Author(s):  
Sampath Emani ◽  
M. Ramasamy ◽  
Ku Zilati Ku Shaari
Keyword(s):  
Surface Roughness ◽  
Crude Oil ◽  
Flow Velocity ◽  
Deposition Rate ◽  
Heat Exchangers ◽  
Cfd Simulations ◽  
Deposition Velocities ◽  
Computational Fluid Dynamics Cfd ◽  
Lower Temperature ◽  
Oil Fouling

One of the major concerns in petroleum refinery preheat trains is identified as fouling. Fouling impacts the refinery economics and environment heavily. Various approaches to mitigate fouling have not yielded the desired results. This is due to lack of understanding on the effect of influencing forces on crude oil fouling in heat exchangers. Therefore, this study attempts to investigate the effects of various forces such as gravity, Saffman Lift, drag and thermophoretic on crude oil fouling in heat exchangers through Computational Fluid Dynamics (CFD) simulations. From the simulations, it is observed that the higher particle size and particle concentration resulted in higher deposition of particles. Deposition velocities increase for larger sized particles and decrease for small and medium sized particles. The Increased flow velocities and surface roughness increases wall shear and mitigate fouling. Lower temperature gradients at the heat exchanger surface decreases deposition rates due to high thermophoretic forces. The mass deposition rate is reduced by 10.3 and 16.9% with 0.03 and 0.05 Pa, respectively, for 0.14 m/s flow velocity. Also, the mass deposition rate is reduced by 15.6 and 25.1% with 0.03 and 0.05 Pa, respectively, for 0.47 m/s flow velocity. With increased surface roughness from 0.03 to 0.05 mm, the mass deposition rate is reduced by 11.48 and 19.18%, respectively, for 0.14 m/s flow velocity. Also, for 0.47 m/s flow velocity, the mass deposition rate is reduced by 18.84 and 32.92% for 0.03- and 0.05-mm surface roughness, respectively.

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