Parametric understanding of vapor transport of hollow fiber membranes for design of a membrane humidifier

Nguyen, Xuan Linh; Vu, Hoang Nghia; Yu, Sangseok

doi:10.1016/j.renene.2021.06.003

Cited by 19 publications

(6 citation statements)

References 35 publications

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“…The humidifier wa designed for a 5 kW PEMFC system and to work in both water-to-gas and gas-to-ga modes. The membrane characteristics were taken from the literature [24]. The humidifier module was divided into three control volumes: (1) the inlet manifold that takes the supply air and distributes it to the membrane tubes; (2) the heat and mass exchanger, which includes the membrane bundle comprising tubes housed in a shell; and (3) the outlet manifold that exhausts the moist air from the humidifier.…”

Section: Gas-to-gas Membrane Humidifiermentioning

confidence: 99%

“…The humidifier was designed for a 5 kW PEMFC system and to work in both water-to-gas and gas-to-gas modes. The membrane characteristics were taken from the literature [24].…”

Section: Dry Air Outletmentioning

confidence: 99%

“…The conductive mass transfer coefficient represents the diffusivity of vapor in the membrane, which was taken from experimental results [24]. The mass transfer rate can then be calculated with the effectiveness:…”

Section: Mass Transfermentioning

confidence: 99%

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A Lumped-Mass Model of Membrane Humidifier for PEMFC

Nguyen

2022

Energies

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Maintaining the performance of a fuel cell stack requires appropriate management of water in the membrane electrode. One solution is to apply an external humidifier to the supply gases. However, the operating conditions change continuously, which significantly affects the humidifier performance and supply gas characteristics. A straightforward humidifier module is needed for integration with the fuel cell system model. In this study, a lumped-mass model was used to simulate a hollow-fiber membrane humidifier and investigate the effects of various input conditions on the humidifier performance. The lumped-mass model can account for heat transfer and vapor transport in the membrane bundle without losing simplicity. The humidifier module was divided into three parts: a heat and mass exchanger in the middle and two manifolds at the ends of the exchanger. These components were modeled separately and linked to each other according to the flow characteristics. Simulations were performed to determine the humidifier response under both steady-state and transient conditions, and water saturation was observed in the outlet manifold that may affect the humidifier performance. The findings on the effects of the operating conditions and humidifier dimensions on the cathode gas can be used to improve humidifier design and control.

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Section: Gas-to-gas Membrane Humidifiermentioning

confidence: 99%

“…The humidifier was designed for a 5 kW PEMFC system and to work in both water-to-gas and gas-to-gas modes. The membrane characteristics were taken from the literature [24].…”

Section: Dry Air Outletmentioning

confidence: 99%

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A Lumped-Mass Model of Membrane Humidifier for PEMFC

Nguyen

2022

Energies

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“…Most of the studies in the literature focus on steady state operating conditions when assessing membrane humidifiers, e.g. (Cahalan et al 2017;Nguyen, Vu, and Yu 2021;Pollak et al 2023). A previous study (Pollak et al 2023) investigated the same type of humidifier as discussed in our work, but focuses on detailed CFD model that is not suitable for system simulations with transient operation due to its long calculation times.…”

Section: Introductionmentioning

confidence: 99%

Steady State and Dynamic Simulation of a Small-Scale Hollow Fiber Membrane Humidifier

Pollak,

Kutz,

Schulze

et al. 2023

Linköping Electronic Conference Proceedings

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Membrane humidifiers are often used in mobile Proton Exchange Membrane (PEM) fuel cell systems to humidify the supply air of the fuel cell. The purpose of a humidifier in a PEM fuel cell system is to prevent a dry-out of the fuel cell membrane. In this paper, a humidifier model based on the number of transfer units (NTU) approach is set-up in Modelica, calibrated and validated using measurement of a test rig. In a first step, the model is evaluated for steady state operating conditions. Second the developed membrane humidifier model is simulated with dynamically changing operating conditions that are typical for mobile applications. Those simulation results are then compared to measurements. The aim of our study is to evaluate the accuracy of the NTU humidifier model under various operating scenarios. Our results indicate that the NTU model is suitable to predict the water transfer under steady state as well as dynamically changing operating conditions with low deviations to measurements.

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“…Hollow fiber membrane technology has become key in the fields of environmental protection, resource recovery, the new energy industry, and the upgrading of traditional industries. In recent years, hollow fiber membrane modules have become widely used in wastewater treatment [1][2][3], membrane extraction [4][5][6][7], gas separation [8][9][10], and air humidification [11][12][13][14][15] and dehumidification processes [16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Flow-Induced Vibration on Heat and Mass Transfer Performance of Hollow Fiber Membranes in the Humidification/Dehumidification Process

et al. 2021

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Cross-flow hollow fiber membranes are commonly applied in humidification/dehumidification. Hollow fiber membranes vibrate and deform under the impinging force of incoming air and the gravity of liquid in the inner tube. In this study, fiber deformation was caused by the pulsating flow of air. With varied pulsating amplitudes and frequencies, single-fiber deformation was investigated numerically using the fluid–structure interaction technique and verified with experimental data testing with a laser vibrometer. Then, the effect of pulsating amplitude and frequency on heat and mass transfer performance of the hollow fiber membrane was analyzed. The maximum fiber deformation along the airflow direction was far larger than that perpendicular to the flow direction. Compared with the case where the fiber did not vibrate, increasing the pulsation amplitude could strengthen Nu by 14–87%. Flow-induced fiber vibration could raise the heat transfer enhancement index from 13.8% to 80%. The pulsating frequency could also enhance the heat transfer of hollow fiber membranes due to the continuously weakened thermal boundary layer. With the increase in pulsating amplitude or frequency, the Sh number or Em under vibrating conditions can reach about twice its value under non-vibrating conditions.

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Parametric understanding of vapor transport of hollow fiber membranes for design of a membrane humidifier

Cited by 19 publications

References 35 publications

A Lumped-Mass Model of Membrane Humidifier for PEMFC

A Lumped-Mass Model of Membrane Humidifier for PEMFC

Steady State and Dynamic Simulation of a Small-Scale Hollow Fiber Membrane Humidifier

The Effect of Flow-Induced Vibration on Heat and Mass Transfer Performance of Hollow Fiber Membranes in the Humidification/Dehumidification Process

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