Numerical investigation of ejector transient characteristics for a 130‐kW PEMFC system

Liu, Zhanrui; Zhi, Liu; Jiao, Kui; Yang, Zirong; Zhou, Xia; Du, Qing

doi:10.1002/er.5156

Cited by 44 publications

(9 citation statements)

References 35 publications

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“…The gas involved in the reaction reaches the proton exchange membrane through the diffusion layer on the electrode. On the anode side of the membrane, hydrogen is dissociated into hydrogen ions and electrons under the action of the catalyst, and hydrogen ions form hydronium ions in the carrier of water and reach the cathode through the PEM, thus completing the proton transfer process [7][8][9][10][11][12][13]. The anode reaction equation is as follows:…”

Section: The Working Principle Of Pemfcsmentioning

confidence: 99%

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Experimental Investigation into the Performance of PEMFCs with Three Different Hydrogen Recirculation Schemes

Li,

Wang,

et al. 2024

Inventions

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Hydrogen recirculation systems (HRSs) are vital components of proton exchange membrane fuel cells (PEMFCs), and it is necessary to investigate different HRS schemes to meet the needs of high-power PEMFCs. PEMFCs are developing in the direction of low cost, high power, wide working conditions, low noise, compact structure, etc. Currently, it is difficult for hydrogen recirculation pumps (HRPs) to meet the flow requirements of high-power PEMFCs. HRPs inevitably have high parasitic energy consumption, loud noise output, high cost, easy leakage, and high failure rates. Therefore, it is necessary to study different HRS schemes to develop a better solution for high-power PEMFCs. In this study, the functional prototype of a piping and instrumentation diagram (P&ID) based on three HRSs of HRPs was designed, and a functional prototype was built. Working according to the analysis and comparison of PEMFC performance test data, we find that the net power trend of PEMFC systems using three different HRS technology schemes is consistent. The ejector scheme and the combination scheme do not reduce the performance of PEMFCs and have advantages in different power ranges, such as 24 A, 48 A, and other small current points. The PEFMC system net power order is as follows: ejector scheme > HRP scheme > combination scheme. At about 120 A, the net power outputs of the three HRS schemes in the PEMFC system coincide. From around 180 A onwards, the PEMFC system power of the combined HRS scheme gradually dominates. At 320 A, the PEFMC system net power order is as follows: combined HRS scheme > HRP scheme > ejector scheme.

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Section: The Working Principle Of Pemfcsmentioning

confidence: 99%

“…For PEMFCs, apart from high efficiency, the influence of hydrogen fuel supply on the fuel utilization rate and system efficiency should also be considered [7][8][9]. With the development of PEMFCs towards the high-power range, a massive amount of liquid water will inevitably be produced when PEMFCs work at high current densities.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation into the Performance of PEMFCs with Three Different Hydrogen Recirculation Schemes

Li,

Wang,

et al. 2024

Inventions

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“…Yan et al [19] optimized structural parameters with six different sequenc Recently, several studies have been carried out to improve the performance of continuous ejectors. Further, it is known that the structural parameters and operating conditions have an important effect on the entrainment ratio [7][8][9][10][11][12]. Pei et al [13] used the dynamic pressure drop boundary in the CFD model to optimize the nozzle diameter, the mixing chamber diameter, the mixing chamber length, and the nozzle exit position, respectively.…”

Section: Introductionmentioning

confidence: 99%

Coupling Global Parameters and Local Flow Optimization of a Pulsed Ejector for Proton Exchange Membrane Fuel Cells

Li,

Sun,

Bao

2024

Sustainability

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Proton exchange membrane fuel cells (PEMFCs), as an important utilization of hydrogen energy, contribute to the sustainable development of global energy. Pulsed ejectors have a high potential for improving the hydrogen utilization of PEMFCs in the full operating range by circulating unconsumed hydrogen. In this study, a pulsed ejector applied to a 120 kW fuel cell was designed, and the flow characteristics were analysed using computational fluid dynamics (CFD). Based on the data from the CFD model, the global optimization of the ejector was carried out using the Gaussian process regression (GPR) surrogate model and the grey wolf optimization (GWO) algorithm. The local structure was then further optimized using an adjoint method coupling streamlining modification that takes into account the local flow characteristics. The CFD results showed that, under a fixed structure, increasing the pressure difference between the secondary flow and the ejector outlet would promote boundary layer separation, shorten the shockwave chain length, change the effective flow area of the secondary flow, and lower the entrainment ratio (ER). The analytical results from the GPR model indicated significant interactions among the structural parameters. The globally optimized ejector using GPR and GWO improved the hydrogen entrainment ratio from 1.42 to 3.12 at the design point. Furthermore, the results of streamlining local optimization show that the entrainment ratio increased by 1.67% at the design point and increased by up to 3.99% over the full operating range compared to the optimized ejector by global optimization.

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“…The static ejector primarily uses the suction and turbulent diffusion of the high-speed jet (which is created by the high-pressure gas from nozzle) to enroll the low-pressure gas into the equipment, and the energy transfer process is accomplished through the direct contact and mixing of the two gases with different pressures. Static ejectors have the benefits of simple structure, low cost, and low sensitivity to impurities [9,10]. However, the isentropic efficiency of static ejector is low due to the viscous dissipation in the turbulent mixing [11], and its pressurization capacity is limited when the gas pressure ratio between gases is small [12].…”

Section: Introductionmentioning

confidence: 99%

Preliminary Test of Gas Wave Ejector in Coalbed Methane Well Site and Impact Analysis of Fluid Medium Characteristics on Its Pressure Port Design

Zhao

et al. 2023

International Journal of Energy Research

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Gas wave ejector (GWE) is an efficient energy conversion device which can recover and utilize excess pressure energy of high pressure fluid. It has significant application value in the sustainable development of energy resources, including the exploitation and transportation of natural gas. The first practical application test of GWE in the natural gas industry is completed in this study. The mechanisms and regulations of the effect of actual gas properties on the pressure port design of GWE were also investigated. The primary conclusions are as follows: the composition of working medium significantly affects the propagation velocity of pressure waves. The wave propagation velocity increases as methane purity (φCH4) rises. The equipment efficiency was decreased by up to 23% of the optimal value as a result of the variation in port position brought on by the increase in φCH4 from 0.7 to 1.0. The variation of working pressure ratio has a greater impact on the device performance than the pressure value when the pressure port design kept unchanged. The intake temperature fluctuation in the range of -30°C to 50°C has no obvious influence on the ideal port design. In the coal-bed methane well site industrial test, GWE accomplishes a recovery of low-pressure well by roughly 8.83 × 10 3 N m 3 / d , demonstrating its excellent ejection capacity. In addition, the variable speed test conducted under different working conditions shows that the equipment performance can be effectively enhanced by adjusting the rotation speed as the equipment structure remains unchanged with the changing working pressure/pressure ratio. In the field test range of this study, the increase of equipment ejection rate obtained by speed adjustment can rise up to 12% of the corresponding value at the designed rotation speed.

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Numerical investigation of ejector transient characteristics for a 130‐kW PEMFC system

Cited by 44 publications

References 35 publications

Experimental Investigation into the Performance of PEMFCs with Three Different Hydrogen Recirculation Schemes

Experimental Investigation into the Performance of PEMFCs with Three Different Hydrogen Recirculation Schemes

Coupling Global Parameters and Local Flow Optimization of a Pulsed Ejector for Proton Exchange Membrane Fuel Cells

Preliminary Test of Gas Wave Ejector in Coalbed Methane Well Site and Impact Analysis of Fluid Medium Characteristics on Its Pressure Port Design

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