Thermal Management of Fuel Cell Systems

In this paper, a cooling channel was incorporated in the fuel cell to analyse the effect of cooling on fuel cell performance. Four different types of coolant combinations, namely DI100 (100% Deionised water), PG10 (90% DI water + 10% Propylene Glycol), PG20 (80% DI Water + 20% Propylene Glycol), and PG30 (70% DI Water + 30% Propylene Glycol) are used to analyse the fuel cell performance. A computational fluid dynamics model relying on a finite volume technique was used to assess efficiency. Performance evaluation was described as system temperature, operational parameters, coolant, and cooling channel geometry. The PEM fuel cell performance was good at PG30 combination, especially at high operating temperatures. The obtained results specify that the fuel cell performance was good at 356k. A decline in fuel cell performance was observed at temperatures between 362 and 371 k, obtained with the PG10 and PG20 conditions.

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Abstract The current research status of fuel cells in the space field is first introduced, followed by an analysis of the comprehensive utilization mode of fuel cell energy from three aspects: water, gas, and heat. The fuel evaporated from the liquid hydrogen and liquid oxygen tanks of spacecraft can be used for fuel cell power generation. The heat generated by fuel cells can be used to preheat gases through a dual-channel heat exchanger, achieving thermal energy recovery for hydrogen and oxygen fuels. The water produced by fuel cells can be separated and recovered through static drainage for reuse in heating control or environmental control systems. A prototype of a fuel cell power generation system is designed and relevant performance tests are conducted. When the fuel cell system stably generates 400W of power, approximately 215W of waste heat can be reused. The utilization efficiency of hydrogen and oxygen fuels reaches over 97%, and the water recovery efficiency of the system reaches over 95%.

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In the paper, a model of a heated building using a PEM (proton exchange membrane) fuel cell is presented. This work introduces a novel and more comprehensive depiction of the thermal processes occurring within a fuel cell under transient conditions. The developed PEM fuel cell model was synergistically incorporated with a thermodynamic model of a build-ing. The resulting mathematical framework provides insights into the building's performance concerning fluctuating am-bient temperatures and the heating system powered by the PEM cell. The developed mathematical model delineates the interplay between the building's thermodynamics and the fuel cell in the context of the devised heating control system featuring an indirect heat distribution mechanism.

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Abstract The stable output of power and the effective control of stack temperature play a very important role in the durability and stability of fuel cell hybrid vehicles. In actual working conditions, energy management of power system and thermal management of Proton Exchange Membrane Fuel Cells (PEMFCs) need to be coordinated with each other to jointly ensure the efficient and stable operation of vehicles, however, most of the research in these two directions is independent. In response to the research gaps mentioned above, the concept of adaptability has been proposed for the first time with the aim of combining these two systems for research. This paper takes the fuel cell hybrid vehicle as the research object and establishes the energy management system and thermal management system model based on Matlab/Simulink software. In order to investigate the adaptability of energy management strategies to the temperature control system, two representative types of rule-based and optimization-based energy management strategies (power-following strategy, PFS, and adaptive equivalent hydro... Read More

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Abstract The adoption of proton exchange membrane fuel cell (PEMFC) technology in heavy-duty trucks represents a promising solution for addressing the pressing issues of emissions and sustainability in the transportation sector. Achieving high-endurance operation is critical for the success of these systems, and effective cooling is central to this goal. This paper explores innovative cooling topologies and control strategies designed to extend the endurance and operational longevity of dual PEMFC stack systems in heavy-duty truck applications. To address these issues, a comprehensive analytical model for a dual PEMFC stack system is developed to assess the heat generation within the fuel cell stacks, enabling a meticulous evaluation of the cooling requirements. Two strategies for controlling coolant bypass flow are evaluated, one based on coolant temperature and the other based on stack temperature, during dynamic operation. Three different topologies are designed to achieve efficient cooling systems, and their impact on parasitic power and energy consumption is examined. The result... Read More

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Abstract Hydrogen energy is an important means of achieving decarbonization goals. Hydrogen fuel cells have broad application prospects due to their high-power output and wide temperature range. To improve the heat dissipation capacity of the fuel cell thermal management system, this paper establishes a simulation model of a 60kw fuel cell. The performance of the fuel cell engine thermal management system model under optimal operating parameters is studied by taking the temperature of the inlet and outlet water of the stack as the observation value. This is significant in improving the thermal environment of the fuel cell engine and ensuring its safe and efficient operation.

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The safe and efficient working of fuel cells depends on the thermal management of the heat generated during the electrochemical process.

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The energy management system and thermal control of fuel cell in fuel cell vehicles plays a crucial role in ensuring their stable and efficient operation.This study presents a novel fuel cell powertrain energy management system control strategy considered the temperature fluctuation based on deep reinforcement learning.A comprehensive SIMULINK model, encompassing fuel cell cooling system and stack models, was constructed for the fuel cell, followed by simulation testing under various temperature scenarios.To validate the robustness and stability of the control system, the standard operating conditions -US06 were employed for experimental verification.The experimental results highlight the effectiveness of the designed fuel cell energy management system in achieving transient temperature stabilization.Additionally, the results revealed that stable operation temperatures correlate with reduced hydrogen consumption.Furthermore, it's noted that fuel cell hydrogen consumption displays substantial variation under uniform operating conditions at varying temperatures.This highlights the key ... Read More

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<title>Abstract</title> The performance of fuel cells is influenced by many factors, among which operating temperature is crucial. Therefore, this study focuses on analyzing the performance of fuel cells at different temperatures and optimizing operational parameters at the optimum temperature condition to enhance the performance and lifespan of fuel cells. The research finds that the optimal temperature for fuel cells is 69.9C, with an efficient operating temperature range of 6080C, and the optimal flow rate range is 10001600 ml/min. The influence of back pressure on fuel cell performance becomes less significant when it exceeds 2.5 bar. Furthermore, this study utilizes a Gaussian process regression model to optimize the performance of fuel cells under different temperature, flow rate, and back pressure combinations. Regression analysis model predictions suggest that the optimum operating temperature is 71C, with an optimal back pressure range of 0.91.4 bar and a flow rate range of 13101600 ml/min.

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Abstract This paper introduces the application demands and research progress of fuel cells in the space field. Subsequently, an analysis of the comprehensive energy utilization modes of fuel cells from the aspects of water, gas, and heat is conducted. The fuel evaporated from the liquid hydrogen and liquid oxygen tanks of spacecraft can be used for fuel cell power generation, and the heat generated by fuel cells, together with the low-absorption and low-emissivity thermal control coatings, maintains the temperature of the spacecraft in the shadow area. The product water from fuel cells can be purified for reuse in thermal control, environmental control, and water electrolysis cells. The hydrogen and oxygen produced by electrolyzing water can be recycled for fuel cell power generation, and the oxygen can also be used for environmental control and life support, while the hydrogen can be used for methane production. To reduce system weight and achieve comprehensive utilization of energy and resources, integrated system design and research on regenerative fuel cell system principles are ... Read More

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Energy Management Strategies for Fuel Cell Vehicles: A Comprehensive Review of the Latest Progress in Modeling, Strategies, and Future Prospects

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Temperature plays a crucial role in efficiency improvement and lifespan extension of the fuel cell system which encourages energy management strategy (EMS) taking thermal into consideration. However, sluggish thermal response prevents the fuel cell performance from tracking the optimal states during scenarios with significant power variations, which was disregarded in the previous works. To solve this issue, an online hydrogen consumption minimization guarantee strategy (HCMG) including thermal management is proposed which is divided into two parts: 1) primary power distribution strategy, where a model predictive control (MPC) based EMS is employed herein to distribute power between fuel cell and battery with the objectives of minimizing hydrogen consumption as well as maintaining the state of charge (SOC), and 2) HCMG, where a modified MPC based method is exploited herein to track the reference power and optimal temperature with minimum hydrogen consumption by adjusting both the duty cycle of fan and fuel cell current. The presented approach ascertains hydrogen consumption reduction... Read More

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In this paper, fuel cell micro combined heat and power with green hydrogen production is investigated for a residential house. Solar and wind energy were investigated for green hydrogen production. The performance of the micro-CHP system was evaluated using yearly energy coverage rate as an index, defined by the energy production and need ratio. A dynamic mathematical model of PEM fuel cell combined with the condensing boiler, supplied by local production of green hydrogen was developed. It was validated based on the yearly measurements in the FC micro-CHP unit installed in a French residential house. The key factors in the micro-CHP operating strategy were the fuel cell heat generation, stop phases, and regeneration which control water temperature, fuel cell life cycle, and annual performance. For conventional residential house in Normandy, the fuel cell operates for a short period during a summer day and the stored hot water was sufficient for heat demand. For winter typical day, the fuel cell operates continuously with maximum heat production. Electricity demand is satisfied and t... Read More

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Hydrogen can serve as an abundant, green, low-carbon, and widely applicable secondary energy source, holding significant importance in building a clean, low-carbon, secure, and efficient energy system and achieving carbon peak and carbon neutrality goals. In the research of hydrogen fuel cells, thermal management, particularly cooling methods, plays a crucial role in the operation of the battery units. This paper primarily focuses on cooling methods in thermal management, using factors such as arrangement, cooling medium, and environmental temperature as variables to establish a simulation model for the thermal behavior of cylindrical hydrogen fuel cells and conduct a parametric study. The research findings indicate that enveloping the battery with a cooling medium can enhance heat dissipation by 19 %. Arranging the hydrogen fuel cell units in a symmetrical rectangular pattern yields excellent heat dissipation results. The battery's maximum temperature increases with the rise in environmental temperature, with every 5 K increase in environmental temperature resulting in a 1.01 % rise... Read More

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Abstract This research paper presents analysis of heat generation problem in Proton Exchange Membrane (PEM) fuel cell using COMSOL Multiphysics software. PEM fuel cells are widely recognized for their high electrical power output and environmental sustainability. However, in a PEM fuel cell around 50 to 60 % of energy generated from chemical reactions is dissipated as heat energy. To address this issue PEM fuel cell stack model is designed and thermal modeling is carried out to evaluate its performance. Based on thermal modeling of surface temperature distribution of cell it is found that the cathode side of PEM fuel cell is warmer and generates more heat as compared to other parts due to the exothermic reactions,slow reaction rate,joule heating effect and material properties.Moreover, it is also found that there is uniform temperature distribution across the cell due to rapid heat conduction from cathode side to the surface of the cell.The results of this study show that due to more heat generation on cathode side temperature will tend to increase.This increasing temperature enhance... Read More

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The thermal management of proton exchange membrane fuel cells is of great importance during the actual operation of the fuel cell. This study aims at the control of fuel cell coolant inlet and outlet temperature, considering the model uncertainty and disturbance, an output feedback controller is designed based on <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$H_{\infty}$</tex> . The simulation and experiment results show that both the inlet and the outlet coolant temperature can be kept at desired value even under the dynamically changing loads, which verifies the robustness of the proposed controller.

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The operating parameters of proton exchange membrane fuel cells (PEMFCs) are very effective at generating heat. The study examined and evaluated parameters that can help determine fuel cell (FC) performance. The parameters and structures used in systems have been examined. In this context, performance evaluations have been made by performing electrochemical analyses of PEMFCs. Evaluations about how the study parameters affect the performance was made on MATLAB and the results were presented. As a result of the study, it was seen that the operating temperature increased the efficiency until it reached certain limits. On the other hand, although the performance-enhancing effects of the working pressure are observed, high pressure appears as an obstacle. Air stoichiometric rate is another variable that affects FC performance. While high stoichiometric rates improve performance, they can adversely affect the membrane. According to the simulation result, it was found that the working temperature, working pressure and air stoichiometry should be optimized together.

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Energy has allowed the development of our society and currently, the hydrogen-powered fuel cell is the most promising energy source of the future since it would help to eliminate serious problems such as climate change and economic inequality. The fuel cell converts the chemical energy of the reactants used into electrical energy and produces water and heat as by-products during its operation. The proton exchange membrane fuel cell is expected to play a key role in the future energy system due to its favourable characteristics and its application in mobile phones, electric vehicles, distributed power systems, submarines and aerospace applications. To optimize the operation of the fuel cell, models have been developed that represent it as a structural, dimensional, thermal and state system, which requires -as a contribution to technological development-, a strategic and systemic vision. The document analyzes the technique of numerical methods, to ensure optimal operation of the Proton exchange membrane fuel cell, addressing non-linearities of electrical behaviour and the imprecision o... Read More

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The lately technology advancements of usage for fuel alternate energy source has gained tremendous pace with several organizations leading active development in the same sector. From all the technologies currently under advance stage of development, hydrogen powered fuel cell technology looks to be promising with very little disadvantages. Major challenge in the same field is the efficiency and thermodynamic voltage improvement by different avenues. The impacts of change in pressure in supplied hydrogen and oxygen, its effects on thermodynamic voltage and possible efficiency improvement. With the improvement in fuel cell voltage, number of fuel cells requirement can be dropped reducing the required area for mounting on mobile applications. This study details the calculations of required fuel flow, air flow, exhaust flow etc. with different pressure is determined. Supercharged fuel cell conceptual study is performed.&#x0D;

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The high-efficiency thermal management is one of the major challenges for fuel cell vehicles due to the diversity and complexity of the components and systems. Thermal management systems and corresponding control strategies can affect the components performance, durability and reliability, the vehicles driving performance, fuel economy and occupant thermal comfort. The main objective of this study is to perform multi-case simulation analysis of the fuel cell vehicle thermal management system through modeling to derive the operating mechanism and thermal performance analysis of each subsystem and integrated system. To achieve this purpose, an integrated thermal management system model with different control strategies was proposed based on a fuel cell vehicle prototype, powered by a 65 kW proton exchange membrane fuel cell stack and a Li-ion battery with a capacity of 15 kWh, which considers the cooling of the driving system, fuel cell stack, battery and cabin. The results showed that the critical temperature of each subsystem could be controlled within a reasonable range even in th... Read More

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This paper reviewed the recent research advances in the thermal management issues of Proton-Exchange-Membrane-Fuel-Cells (PEMFC) from design and control perspectives. Most of the current research on PEMFC thermal management have focused mainly on two main aspects; the cooling technology and stack cold start. However, PEM fuel cell thermal management involves many other issues such as effective heat-dissipation, temperature-distribution, temperature-control, and parasitic power, which are crucial in the process of thermal management research. The PEMFC temperature control has been weakly explored in the current review papers and thus, it has a potential research gap to be further studied in the area of PEMFC research. In addition, a review of the latest research in fuel cell technology is necessary due to its rapid development, especially with the increasing demand for fuel cell vehicles in recent years. In this paper, the PEMFC heat production, transfer and dissipation, and their related calculation equations are first reviewed. Then, the thermal management of PEMFC is reviewed from ... Read More

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An integrated thermal management system (VITMS) of hydrogen fuel cell vehicle (FCV) is proposed to solve the issues of poor temperature control and high energy consumption in current dispersed TMS. The vehicle energy integration is realized by coupling the key subsystems of cabin, fuel cell, power battery and motor through the waste-heat source heat pump (WSHP). The temperature control capability under extreme working conditions are analyzed. The energy consumption of three heating modes under extreme cold conditions is evaluated. The results show that VITMS has excellent thermal control performance and can realize fourteen work modes such as cooling, heating, preheating, defrosting and energy recovery, ensuring the optimal temperature ranges and temperature uniformity of fuel cell, power battery, motor, and cabin. VITMS using WSHP offers superior energy saving effect in extreme cold conditions, which can reduce equivalent hydrogen consumption by 12.21% and 3.6%, and increase maximum driving range by 29.34% and 8% compared to PTC and air-source heat pump (ASHP). The cabin heating tim... Read More

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The fuel cell system is an emerging technology for power generation because of its higher energy conversion efficiency and extremely low environmental pollution. Depending upon the applications, there are several types of fuel cell systems used for stationary, mobile and portable power generation. The most common types of fuel cells considered are the proton exchange membrane (PEMFC), direct methanol (DMFC), phosphoric acid (PAFC), molten carbonate (MCFC) and solid oxide (SOFC) fuel cells. These fuel cells use hydrogen as the fuel. If a hydrocarbon fuel is used, the fuel needs to be reformed to make it hydrogen rich or almost pure hydrogen depending upon the operating temperature and the type of the fuel cell. Heat exchangers play an important and critical role in the fuel cell systems to reform the fuel, to preheat the fuel and oxidant to the cell/stack operating temperature, to humidify the incoming fuel and oxidant streams, to recover water and energy, to cool the fuel cell stack and incoming high pressure air and reformed hydrogen, and in general, to control thermal management of... Read More

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Utilizing waste heat from fuel cells effectively has the potential to increase total energy utilization efficiency. Waste heat usage is a developing area of thermal management for fuel cell vehicles (FCV). The efficiency of heat exchange has not been taken into account, and conventional fuel cell vehicles do not properly utilize waste heat. This study recommends a heat exchanger only thermal management system (HEOS) and conducts thermodynamic modeling and controlled quantity simulation based on global optimization in order to evaluate the effectiveness of waste heat utilization in the proposed system structure. In order to meet the heating requirements of fuel cell vehicles in low temperature conditions, the system eliminates positive temperature coefficients (PTC) and utilizes an effective heat exchanger. By specifying an objective function, an optimization issue, and a global optimization technique using dynamic programming, the global optimal fuel cell energy-saving control effect is attained. The findings demonstrate that the suggested fuel cell vehicle thermal management system ... Read More

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Fuel cells attract attention because of their high-energy conversion efficiency, but they are still known for significant heat generation. Therefore, the heat generated must be removed efficiently in order to prevent the membrane and the catalyst from overheating and degrading. Also, the heat removed from the reactant and product streams is insignificant, so it highlights that most portion of the heat must be removed through the cooling system. Choosing an effective approach for cooling fuel cells is very challenging because it directly affects the durability, cost, and performance. As was mentioned in the previous chapter, cooling methods of fuel cells are divided into several categories. One of the most efficient cooling strategies is using liquid flow because of its very high heat capacity. In this chapter, the points, advantages, and disadvantages of using this approach are discussed. Also, the results of the related simulation and the experimental studies on this strategy are compared.

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Maximizing the waste heat utilization of the fuel cell without controlling the operating temperature the fuel cell at each power output point will increase the hydrogen consumption of the fuel cell, and thus the energy consumption of the system. In this paper as to ensure that the waste heat utilization subsystem always runs at low energy consumption, the waste heat utilization subsystem model of fuel cell vehicle is constructed, and the fuel cell operating temperature prediction model is established. Taking the optimal operating temperature of the fuel cell under each output power as the reference trajectory, the optimization target is set as reducing the difference between the fuel cell operating temperature and the ideal operating temperature. Thus, a predictive controller with the function of following the optimal working temperature of fuel cell is designed for the waste heat utilization subsystem. The effectiveness of the predictive controller is verified under NEDC and CHTC-HT driving cycle respectively. The feasibility and effectiveness of the predictive controller are verifi... Read More

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The transient and steady-state behaviors of a fuel cell system play an important role to analyze inherent characteristics and design control strategies. In this chapter, a control-oriented model of a fuel cell system is formulated in detail. First, comparison of existing fuel cell models in the literature is discussed and the motivation for establishing a lumped model in this thesis is described in Sect. 2.1. In Sect. 2.2, the general model of fuel cell stack is provided with respect to mass flow balance, electrochemical balance, and thermal energy balance. Moreover, models regarding to solid oxide fuel cell (SOFC) and proton exchange membrane fuel cell (PEMFC) are provided in Sects. 2.3 and 2.4, respectively. Finally, modeling of auxiliary components in the fuel cell system is presented in Sect. 2.5.

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Because of its clean or zero-emission nature, the PEM fuel cell is considered a potential energy conversion device for power production. The performance of the PEM fuel cell is known to be influenced by many parameters, such as operating temperature, pressure, and humidification of the reactants. In addition, the operational stability of the PEM fuel cell under these conditions with the purging of water during its operation should also be studied to understand the performance of the PEM fuel cell. Therefore, this paper brings out the effects of cell humidification and cell heating on the performance, especially the operational stability concerning the liquid water removal of the PEM fuel cell. The experiments are conducted on a single PEM fuel cell with mixed flow distributors operating on different cell temperatures and humidification conditions. At dry feed operation of the PEM fuel cell at ambient condition, the cell utilizes around 80.3% of water generated for its membrane hydration, i.e., self-humidification. When the PEM fuel cell is operated at full humidification (100% RH) on... Read More

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Fuel cell electric vehicles (FCEVs) requires proper thermal management of a proton-exchange membrane fuel cell (PEMFC) stack, but conventional thermal management systems (TMSs) cannot manage the thermal requirements of PEMFCs under high-power density at high ambient temperatures. In this study, a stack cooling system coupled with a secondary heat pump in an FCEV is suggested. The enhanced thermal flexibility of the secondary heat pump system enabled extensive cooling with various TMS configurations. The cooling performance with different TMS configurations was evaluated, considering the thermal and electrical coupling of the heat pump system and the PEMFC stack. The results show that the stack temperature was lowered up to 2.6 C when the excessive cooling load of the stack radiator was distributed to the cabin radiator under a relatively low-power output condition. To dissipate a large amount of waste heat from the stack, TMS requires a temporary shutdown of the cabin cooling system. In this case, utilizing the inactive outdoor heat exchanger as an additional radiator decreased the ... Read More

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Thermal management strategies implemented on-board fuel cell electrified vehicles (FCEVs) are currently based on heuristic reactive approaches. In this framework, developing predictive thermal management approaches that anticipate the travel needs of FCEV users could lead to improved hydrogen savings. However, the theoretical hydrogen saving achievable by predictive thermal management needs assessment first to quantify the technical and economical viability of the technology proposal. This paper lays the foundations in this domain by analyzing the a priori optimal thermal management of a fuel cell system in an FCEV. Initially, an electrochemical and thermal modeling technique for the fuel cell system is described. A reactive rule-based approach is then selected as the baseline controller for the coolant rate and the instantaneous radiator fan state of the FCEV. Then, the optimal control problem formulation for the thermal management of fuel cell systems in FCEVs is discussed and solved using a dynamic programming (DP) based optimization approach that makes use of a priori information... Read More

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The proton exchange membrane fuel cell, as a novel energy device, exhibits a wide array of potential applications. This paper offers a comprehensive review and discussion of modeling and control strategies for fuel cell systems. It commences with a concise introduction to the structure and principles of fuel cells. Subsequently, it outlines modeling approaches for various fuel cell subsystems, encompassing the fuel cell stack, air supply system, hydrogen supply system, thermal management system, and water management system. Following this, it conducts a comparative analysis and discussion of prevalent control strategies for the aforementioned subsystems. Lastly, the paper outlines future research trends and directions in the modeling and control strategies of fuel cells. The aim of this paper is to provide ideas and inspirations for the design and management of membrane fuel cell systems from control aspects.

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Cold start is still a major factor for PEM fuel cell degradation. Using a metal hydride-based preheater can significantly reduce the time to reach temperatures above 0 C without consuming any extra energy due to two specific features of the fundamental thermochemical reaction: First, thermal energy provided during fuel cell operation as waste energy can be stored long-time and loss-free for the next cold start event. Second, providing a hydrogen pressure of 8 bar immediately triggers the exothermal absorption reaction to heat up a system from temperatures as low as -20 C.The manuscript presents the results of a system with a 1 kW PEM fuel cell starting from temperatures of -5 C with and without an active preheating module at a hydrogen pressure of 6 bar. The experiments indicate that the single-cell voltage behavior is improved when the preheating module is active as the lowest values measured are in the range of 0.6 V in contrast to 0.45 V without a preheater. These findings are supported by simulation data of the modeled system, which indicates severe ice formation of up to 87% ... Read More

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In this chapter, the heat generation mechanisms are introduced. Different types of waste heat are explained, namely, reversible heat, irreversible heat, Joule heat, and latent heat of phase change. The heat transport mechanisms within different components of a proton exchange membrane fuel cell (PEMFC) are also introduced. The cooling methods for fuel cell stacks and their pros and cons, as well as their corresponding application scenarios, are well elucidated, for instance, air cooling, heat spreader cooling, liquid cooling, nanofluids cooling, evaporative cooling, flow boiling cooling, heat pipe cooling, and phase-change materials. The functions of each component included in a representative thermal management subsystem of the PEMFC stack are explained. The control strategies applied in thermal management, like proportionalintegralderivative control, model predictive control, fuzzy control, artificial neural network control, adaptive control, and robust control, are presented.

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In this study, a comprehensive set of experimental tests were carried out to investigate individual cell voltage and temperature deviation under different operating conditions in a fuel cell stack. Five key operating conditions were considered: temperature, pressure, anode and cathode relative humidity, and cathode stoichiometry. Different configurations of reactant flow within the stack were also investigated. A 100 cm2 7-cell stack was used for the experiments, and voltage and temperature measurements were taken for each individual cell. Both ANOVA and range analysis method were used to evaluate the results. The findings showed that the performance of the external cells was consistently lower than that of the central ones since its temperature, the parameter that most affected performance, was also lower due to heat losses. Additionally, voltage deviation increased with temperature deviation. The study also revealed that stack performance was improved by an increase in temperature, pressure and cathode stoichiometry, whereas the effect of anode and cathode humidity was not so signi... Read More

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Proton exchange membrane fuel cells (PEMFCs) have the advantages of long operation cycles, high energy efficiency, and no pollution of reaction products. Temperature is an important factor to ensure the operation of fuel cell systems. Too high temperature will cause irreversible damage to the proton exchange membrane, and too low temperature will greatly reduce the power generation efficiency of fuel cells. Therefore, the effective thermal management temperature control can ensure the stable operation of the system under steady state and dynamic variable load. It can also improve the reaction efficiency of the fuel cell system and prolong the life of the fuel cell. This paper mainly summarized the cooling mode and control strategy of PEMFCs based on thermal management system. The application of different cooling methods is further discussed. The characteristics of traditional proportional-integral-derivative (PID) control, fuzzy PID control, predictive control, adaptive control, and other common thermal management control strategies were described in detail. The research status of sc... Read More

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Using hydrogen fuel cells for power systems, temperature conditions are important for efficient and reliable operations, especially in low-temperature environments. A heating system with an electrical energy buffer is therefore required for reliable operation. There is a research gap in finding an appropriate control strategy regarding energy efficiency and reliable operations for different environmental conditions. This paper investigates heating strategies for the subfreezing start of a fuel cell for portable applications at an early development stage to enable frontloading in product engineering. The strategies were investigated by simulation and experiment. A prototype for such a system was built and tested for subfreezing start-ups and non-subfreezing start-ups. This was done by heating the fuel cell system with different control strategies to test their efficiency. It was found that operating strategies to heat up the fuel cell system can ensure a more reliable and energy-efficient operation. The heating strategy needs to be adjusted according to the ambient conditions, as this... Read More

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For a correct management of a PEMFC fuel cell (Proton Exchange Membrane Fuel Cell), it is necessary to incorporate the degradation phenomenon of performance in the control decisions, which is the reason why it is important to be able to quantify its performance throughout its useful life, because ignoring degradation has a direct impact on the system. Therefore, in this work, heat produced during the reaction is proposed as another indicator of degradation. For this purpose, experimental results will be presented that consider the operating conditions and the electrical and thermal energy of a PEMFC stack at two stages of its lifetime. The relationship between the decrease in stack voltage, which is often used as a predictive tool, and the increase in heat generated during the reaction will be demonstrated experimentally.

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In this paper, aiming at the heating problem of fuel cell vehicles in low temperature environment, the principle, advantages and disadvantages of heat pump heating system and PTC heating system are analyzed. In addition, this paper takes a fuel cell bus as an example to analyze the application of PTC heating system in fuel cell vehicles. The results show that PTC heating is the most suitable vehicle heating method in low temperature environment, and the temperature rise rate of fuel cell bus is slow due to the large interior space. This paper also puts forward specific suggestions for the current vehicle heating scheme.

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PEM fuel cell systems in automotive applications must provide a low minimum power compared to their maximum power. Especially systems without external humidification require a rather low stoichiometry and elevated pressure at the cathode to avoid dry-out at low load operation. Targeted experiments show that this may cause flooding, as the gas velocity becomes too low for sufficient liquid water drainage. An increase of the gas velocity would cause a membrane dry-out, negatively impacting the cells performance and lifetime. One solution for this issue is proposed in this work: a dynamic operation of the air system, which is periodically switched between one set point for membrane humidification and another one for liquid water drainage. A sophisticated experimental fuel cell system is used to test the proposed solution on a 100kW stack.

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The vehicles thermal management system is critical to the safety, durability, performance and passenger comfort of fuel cell vehicles, and is also one of the core technologies of fuel cell vehicles. The thermal management system needs to meet the thermal balance of the vehicle under the operating limit conditions and balance the working temperature of different components. This paper analyzes the structure and control strategy of the thermal management system of different vehicle models through the research summary of the current thermal management technology of fuel cell vehicles, summarizes the impact of different parameters on thermal efficiency, and deeply analyzes the technical research field and development in this direction. The direction gives some methods to improve the performance of the thermal management system during the selection of the R&amp;D technology route and the development process of the enterprise.

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Combined heat and power technologies represent an efficient way to ensure energy efficiency, as they promote usage of both electrical and thermal energy, something not done by most traditional energy sources, especially in residential environments. In this context, high-temperature proton exchange membrane fuel cells allow the implementation of combined heat and power systems. Additionally, in this environment, fuel cells are more efficient and less polluting than their traditional counterparts. We present a literature review of energy management in residential systems based on this type of fuel cell. In addition, we classify and detail the current state of fuel cell technologies, paying special attention to their characteristics, mathematical modelling and control, as well as combined heat and power systems and energy management strategies.

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Abstract Thermal management system is importance to the efficiency and durability of fuel cell vehicles, so related researches are carried out on the thermal balance test and evaluation of fuel cells. Through theoretical and technical analysis, a test and evaluation method of thermal management system applied to various extreme conditions is proposed, and the test and evaluation conditions and evaluation indicators of each system of fuel cell vehicles are formed. In this paper, the thermal balance test results of a fuel cell vehicle are analyzed. The research results show that the thermal balance of fuel cell vehicles under extreme conditions reduces power and increases temperature difference to dissipate heat

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Fuel cell is one of the main powers of new energy vehicles. In the fuel cell, bipolar plate is an important component for its normal operation, which plays a variety of roles, such as distributing reaction gas, collecting current, draining water, conducting heat and supporting machinery. Its flow field structure determines the proportion of reaction area, the uniformity of reaction gas distribution, etc., and significantly affects many important parameters such as fuel cell power, current density distribution in the range of electrode plates, voltage consistency between electrode plates, etc., thus determining the working performance index and service life of fuel cell, which is an important content of fuel cell structure design. at present, the hydrogen fuel cell technology is in the initial stage, and there are some problems, such as uneven distribution of reaction gas in the whole system, low conversion rate of hydrogen and electricity, and high production cost, especially the low reaction effect of bipolar plate flow field and the utilization rate of membrane electrode, which ser... Read More

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This paper investigates the potential of predictive thermal management as hydrogen saving enabler for Fuel Cell Electric Vehicles (FCEVs). First, a numerical approach to model the fuel cell system of the FCEV from energy and thermal perspectives is described. A rule-based reactive approach is then considered as baseline controller for the instantaneous radiator fan state and the coolant rate of the FCEV. Subsequently, an optimal predictive thermal management strategy is implemented based on the global optimal principle of dynamic programming (DP). The fuel cell system is simulated while the FCEV performs a 93 kilometer long drive cycle considering different ambient temperatures that respectively represent summer, mid-season, and winter cases. Both baseline reactive thermal management and optimal predictive thermal management approaches are considered in this case. Results highlight how predictive thermal management can enable up to more than 8% hydrogen saving compared with the baseline reactive controller. The viability and usefulness of predictive thermal management for FCEVs is de... Read More

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A solid oxide fuel cell (SOFC) can be fed with several types of fuel, including hydrogen gas, carbon monoxide and methane, which are direct oxidation fuels within the cell. In this paper, models of thermochemical and thermoelectric processes were designed and calculated for three types of fuels by using C++ program, The results indicated the thermal behavior and electrical output of the fuel cell according to the temperature change over its operation period. This study showed that the maximum and minimum values for cell outputs such as reversible voltage, electrical work, heat generated and cell efficiency. The behavior of changing these outputs with the increasing operating temperature was compared for each chemical reaction of three direct oxidation fuels.

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Commercialization of technology of PEMFC (proton electron membrane fuel cells) remains a big obstacle regardless of the broad research on PEM and other fuel cells.High temperature proton exchange fuel cell has found its wide application now days and it is very important to manage the Heat and apply cooling arrangement for the fuel cell stack as durability is at stake when exposed for the longer duration. Considering the heat sources HT-PEM has three heat sources: 1) irreversible joule heating caused by the charge transport in the solid electrolyte or the conductor 2) Reversible heating due to the charge entropy change and 3) irreversible heating of the reaction caused due to the over potential. Considering all the aspect it is found that the optimum temperature for HT PEM Fuel cell is 170 to 180 though it is observed that at 200 the efficiency has shown positive effect. The enormous heat generated by the electrochemical reaction of the fuel cell as a by-product and when it reaches to the extreme limit of the recommended temperature which makes cooling necessary and based on the FC... Read More

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Heat and power cogeneration plants based on fuel cells are interesting systems for energy- conversion at low environmental impact. Various fuel cells have been proposed, of which proton-exchange membrane fuel cells (PEMFC) and solid oxide fuel cells (SOFC) are the most frequently used. However, experimental testing rigs are expensive, and the development of commercial systems is time consuming if based on fully experimental activities. Furthermore, tight control of the operation of fuel cells is compulsory to avoid damage, and such control must be based on accurate models, able to predict cell behaviour and prevent stresses and shutdown. Additionally, when used for mobile applications, intrinsically dynamic operation is needed. Some selected examples of steady-state, dynamic and fluid-dynamic modelling of different types of fuel cells are here proposed, mainly dealing with PEMFC and SOFC types. The general ideas behind the thermodynamic, kinetic and transport description are discussed, with some examples of models derived for single cells, stacks and integrated power cogeneration uni... Read More

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&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Proton exchange membrane fuel cell (PEMFC) is regarded as the reality power source in the 21th century because of its characteristics of high energy density, low working noise, no air pollution, good cold-start performance, quickly start-up and so forth. However, the durability of fuel cell engine is an important factor hindering their mass commercialization and the stack`s consistency is the key factor of the durability for fuel cell engine. Based on the fuel cell water heat management subsystem control strategy, a decoupling control scheme for the temperature management subsystem coolant outlet temperature and inlet temperature is designed to improve the temperature distribution between individual batteries and individual batteries by adjusting the coolant temperature at the outlet and inlet in real time during the operation of the PEMFC system. The control strategy is applied to the 100,000 kilometers durability test for the 41kW fuel cell commercial vehicle. The results show that: To begin with, this contro... Read More

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Vehicle thermal management system (VTMS) is an important part of the safe operation of fuel cell vehicles (FCVs). In this work, an integrated thermal management system was proposed for a fuel cell bus, with 80 kW fuel cell and 105 kWh battery. Liquid cooling is adopted for fuel cell, battery and motor. The model of VTMS was based on AMESim software. Two modes, including cooling and heating, were simulated for VTMS under different ambient conditions. The simulation is performed under a modified New European Driving Cycle (MNEDC), in which the running time is 1180 s and the distance is 10437 m. Results show that the VTMS could fulfill the temperature requirement for both modes. In cooling mode, ambient temperature of 34 C, 37 C and 40 C are considered. The equivalent hydrogen consumption (EHC) is 505.68 g, 522.93 g and 539.48 g respectively. In heating mode, the ambient temperature is set to be 10 C, 5 C, 0 C, and the corresponding EHC is 840.16 g, 783.64 g and 707.53 g, respectively. Besides, EHC at different heating target temperature for the fuel cell and battery was investi... Read More

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Fuel cells produce not only electricity but also heat as a side product. The produced heat can be used in combined heat and power, better known as CHP systems. Using CHP concept with fuel cell operation increases the system net efficiency even more. CHP is well known for high-temperature fuel cells, and different high-temperature fuel cells benefit from this feature. However, low-temperature fuel cells such as PEMFCs are not usually considered for CHP purposes. In the present chapter, we develop the concept of CHP and discuss its applications to both high- and low-temperature fuel cells. This concept is applied to SOFC and PEMFC through different examples and discussions.

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