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A Progress Review on Heating Methods and Influence Factors of Cold Start for Automotive PEMFC System

Tongji University-Pengcheng Liu, Sichuan Xu
  • Technical Paper
  • 2020-01-0852
To be published on 2020-04-14 by SAE International in United States
Fuel cell vehicles (FCV) have become a promising transportation tool because of their high efficiency, fast response and zero-emission. However, the cold start problem is one of the main obstacles to limit the further commercialization of FCV in cold weather countries. Many efforts have made to improve the cold start ability. This review presents comprehensive heating methods and influence factors of the research progress in solving the Proton Exchange Membrane Fuel Cells (PEMFC) system cold start problems with more than 100 patents, papers and reports, which may do some help for PEMFC system cold start from the point of practical utilization. Firstly, recent achievements and goals will be summarized in the introduction part. Then, regarding the heating strategies for the PEMFC system cold start, different heating solutions are classified into self-heating strategies and auxiliary-heating heating depending on their heating sources providing approach. Then, the next part will review the main influence factors for PEMFC system cold start, including the fuel cell stack, PEMFC system integration and design, cold start control strategies. Shutdown purge and heating…
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Investigation of the operating conditions on the water and thermal management for a polymer electrolyte membrane fuel cell by one-dimensional model

Tongji Universtiy-Xuhui Wang, Yaqian Dong, Sichuan Xu
  • Technical Paper
  • 2020-01-0856
To be published on 2020-04-14 by SAE International in United States
Water and thermal management is an essential issue that influences performance and durability of a polymer electrolyte membrane fuel cell (PEMFC). Water content in membrane decides its ionic conductivity and membrane swelling favors the ionic conductivity, resulting in decreases in the membrane’s ohmic resistance and improvement in the output voltage. However, if excessive liquid water can’t be removed out of cell quickly, it will fill in the pores of catalyst layer (CL) and gas diffusion layer (GDL) then flooding may occur. It is essential to keep the water content in membrane at a proper level. In this work, a transient isothermal one-dimensional model is developed to investigate effects of the relative humidity of inlet gas and cell temperature on performance of a PEMFC. Comprehensive physical and chemical phenomenon inside the cell is included, especially the mass transfer of hydrogen, oxygen, vapor and liquid water in gas channels, GDL and CL and non-frozen membrane water in ionomer. Phase change between vapor and liquid water is also considered. The cell’s performances at the conditions of the different…
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Simulation and Parametric Analysis of Battery Thermal Management System Using Phase Change Material

CATARC-Chunjing Lin, Yuhan Sun
Tongji University-Zhao Li, Sichuan Xu
  • Technical Paper
  • 2020-01-0866
To be published on 2020-04-14 by SAE International in United States
The thermophysical parameters and amount of composite phase change materials (PCMs) have decisive influence on the thermal control effects of thermal management systems (TMSs). At the same time, the various thermophysical parameters of the composite PCM are interrelated. For example, increasing the thermal conductivity is bound to mean a decrease in the latent heat of phase change, so a balance needs to be achieved between these parameters. In this paper, a prismatic LiFePO4 battery cell cooled by composite PCM is comprehensively analyzed by changing the phase change temperature, thermal conductivity and amount of composite PCM. The influence of the composite PCM parameters on the cooling and temperature homogenization effect of the TMS is analyzed. which can give useful guide to the preparation of composite PCMs and design of the heat transfer enhancement methods for TMSs.
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Influence of Distributing Channel Configuration and Geometric Parameters on Flow Uniformity in Straight Flow-Field of PEM Fuel Cell

Tongji University-Huili Wei, Guofeng Chang, Jinling Liu, Sichuan Xu
  • Technical Paper
  • 2020-01-1173
To be published on 2020-04-14 by SAE International in United States
Gas distribution of proton exchange membrane fuel cells (PEMFCs) is mainly decided by flow field of bipolar plate. The improper design of distributing channel, nonuniform gas flow distribution and current density distribution among different straight channels are the leading factors that could tremendously undermine the performance and life expectancy of the cell. However, there is lack of research focusing on distributing channel in straight-parallel flow field. In this work, a three-dimensional numerical model of PEMFC cathode flow field is developed with CFD method to investigate the effects of configuration type and width of the distributing channel on pressure distribution in distributing channel and on reactant flow distribution, pressure drop and concentration distribution in multiple straight channel. Effects of electrochemical reaction and formation of water on the flow distribution are taken into consideration. By extending one group of z-type channels to four groups, a new flow field for a full cell is designed. Numerical results indicate that different type and width of distributing channel do affect the flow, pressure drop and gas concentration uniformity. The pressure…
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Parameter Identification for One-Dimension Fuel Cell Model Using GA-PSO Algorithm

Tongji University-Mingzhi Shao, Huili Wei, Sichuan Xu
Published 2019-11-04 by SAE International in United States
When studying on how to identify the proton exchange membrane fuel cell model parameters accurately and quickly, the model frequently used is a lumped parameter model. Compared to this kind of model, one-dimensional dynamic proton exchange membrane fuel cell model can correlate the physical parameters with output characteristics of fuel cell to predict the effects of design parameters, materials and environmental conditions, thus reducing the need for experimentation. However, there is little literature about parameter identification for one-dimensional dynamic models currently. In this paper, a one-dimension dynamic proton exchange membrane fuel cell model with many assumptions for reducing the complexity of calculation is realized in Matlab-Simulink environment. The model consists of five interacting subsystems. The GA-PSO hybrid optimization algorithm is used to identify the parameters of fuel cell model to emulate the output characteristics of different proton exchange membrane fuel cells. This hybrid algorithm is an improved Particle Swarm Optimization Algorithm relying on Genetic Algorithm's strong global search ability, with the aim of maintaining the population diversity and avoiding premature convergence. The result shows that…
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A Lattice Boltzmann Simulation of Gas Purge in Flow Channel with Real GDL Surface Characteristics for Proton Exchange Membrane Fuel Cell

SAE International Journal of Advances and Current Practices in Mobility

Tongji University-Peng Xu, Sichuan Xu, Pengcheng Liu, Xingyu Liu
  • Journal Article
  • 2019-01-0389
Published 2019-04-02 by SAE International in United States
Gas purge is considered as an essential shutdown process for a PEMFC (Proton Exchange Membrane Fuel Cell), especially in subfreezing temperature. The water flooding phenomenon inside fuel cell flow channel have a marked impact on performance in normal operating condition. In addition, the residual water freezes in the subzero temperature, thus blocking the mass transfer from flow channel to porous media. Therefore, the gas purge course is of primary importance for improvement of performance and durability. The water droplet residing in the flow channel can be purged out due to shearing force of gas. In fact, the flow channel is not completely flat due to surface roughness of gas diffusion layer (GDL), meaning the water droplet may climb over obstacles. Moreover, the water droplet may block the flow channel and then be sheared into films on the surface of GDL. The lattice Boltzmann method (LBM), based on the mesoscopic kinetic theory, has recently become a powerful simulation tool for multiphase flow. The main advantages of LBM over traditional computational fluid dynamics (CFD) include capacity for…
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Numerical Analysis and Optimization Design of a Centrifugal Compressor’s Volute for PEM Fuel Cell Vehicle

CATARC-Chunjing Lin
Tongji University-Yuemeng Zhang, Sichuan Xu, Qing Zhan
Published 2019-04-02 by SAE International in United States
Centrifugal compressors used in polymer electrolyte membrane fuel cell systems are different from turbochargers in internal combustion engines, because they are required to work at high speed, low mass flow rate, narrow range which nears surge boundaries. In order to meet these requirements, a centrifugal compressor’s volute is designed, analyzed and optimized on its cross-section area, shape of volute tongue and tapered angle of exit. The numerical results show that surge boundary of the compressor is influenced by spiral area significantly and that volute tongue has a major impact on aerodynamic performances at high mass flow rates.
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An Adaptive Neuro-Fuzzy Inference System (ANFIS) Based Model for the Temperature Prediction of Lithium-Ion Power Batteries

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

China Automotive Technology and Research Center Co., Ltd. (CATARC)-Bin Fan, Chunjing Lin, Fang Wang, Shiqiang Liu, Lei Liu
Tongji University-Sichuan Xu
  • Journal Article
  • 07-12-01-0001
Published 2018-08-14 by SAE International in United States
Li-ion batteries have been widely applied in the areas of personal electronic devices, stationary energy storage system and electric vehicles due to their high energy/power density, low self-discharge rate and long cycle life etc. For the better designs of both the battery cells and their thermal management systems, various numerical approaches have been proposed to investigate the thermal performance of power batteries. Without the requirement of detailed physical and thermal parameters of batteries, this article proposed a data-driven model using the adaptive neuro-fuzzy inference system (ANFIS) to predict the battery temperature with the inputs of ambient temperature, current and state of charge. Thermal response of a Li-ion battery module was experimentally evaluated under various conditions (i.e. ambient temperature of 0, 5, 10, 15 and 20 °C, and current rate of C/2, 1C and 2C) to acquire the necessary data sets for model development and validation. A Sugeno-type ANFIS model was tuned using the obtained data. The numbers of input membership functions (MFs) representing the three input parameters of this model are 1, 2, 3, respectively.…
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A Progress Review on Gas Purge for Enhancing Cold Start Performance in PEM Fuel Cell

Tongji University-Peng Xu, Sichuan Xu
Published 2018-04-03 by SAE International in United States
Cold start capability is one of remaining major challenges in realizing PEMFC (Proton Exchange Membrane Fuel Cell) technology for automotive applications. Gas purge is a common and integral shutdown procedure of a PEMFC automotive in subzero temperature. A dryer membrane electrode assembly (MEA) can store more water before it gets saturated and ice starts to penetrate in the open pores of porous media, thus enhancing cold start capability of a PEMFC. Therefore, gas purge is always performed prior to fuel cell shutdown to minimize residual water in a PEMFC. In the hope of improving effectiveness of purge in a PEMFC vehicle, two important purge parameters are evaluated including purge time and energy requirement. In practice, an optimized gas purge protocol should be developed with minimal parasitic energy, short purge duration and no degradation of components. To conclude, the cold start capability and performance can be consolidated by proper design of gas purge strategies.Despite of its paramount importance, gas purge is not studied in detail and no known efforts have been made to review in detail.…
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Numerical Models for PEMFC Cold Start: A Review

SAE International Journal of Alternative Powertrains

Tongji University-Xin Guo, Xu Peng, Sichuan Xu
  • Journal Article
  • 2017-01-1182
Published 2017-03-28 by SAE International in United States
Startup from subzero temperature is one of the major challenges for polymer electrolyte membrane fuel cell (PEMFC) to realize commercialization. Below the freezing point (0°C), water will freeze easily, which blocks the reactant gases into the reaction sites, thus leading to the start failure and material degradation. Therefore, for PEMFC in vehicle application, finding suitable ways to reach successful startup from subfreezing environment is a prerequisite. As it’s difficult and complex for experimental studies to measure the internal quantities, mathematical models are the effective ways to study the detailed transport process and physical phenomenon, which make it possible to achieve detailed prediction of the inner life of the cell. However, review papers only on cold start numerical models are not available. In this study, an extensive review on cold start models is summarized featuring the states and phase changes of water, heat and mass transfer. To begin with, the states of water in PEMFC are discussed. Then, the distinct stages for cold start process are introduced. Last but not least, various numerical models are reviewed…
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