Hydrogen Fuel Cell System Research Articles

Aerodynamic design of two-stage centrifugal compressor for vehicle hydrogen fuel cell

Abstract The on-board hydrogen fuel cell is a power generation device that converts the chemical energy of hydrogen and oxygen directly into electrical energy. The centrifugal compressor mainly provides oxygen for the cathode of the fuel cell system. With the rapid development of the hydrogen fuel cell industry, the key components of the air compressor field are also developing rapidly. In the technical route, most companies launched two-stage compression centrifugal air compressors in response to the increasing power of the product development trend. The newly developed hydrogen fuel cell system power has reached above 120kW to meet the needs of heavy trucks and other applications. Both the flow rate and pressure ratio of the air compressor are required to increase accordingly. Based on the reduction of parasitic power, the optimal efficiency at the working point of the two-stage centrifugal air compressor is taken as the design goal, from one-dimensional aerodynamic calculation to two-dimensional flow channel design. Finally, the feasibility and accuracy of the aerodynamic design are verified based on key parameters such as pressure ratio, flow rate, and efficiency of the final stage through CFD flow field simulation and test data comparison. The results show that the flow rate is consistent with the calculated flow field, and the maximum error of pressure ratio and efficiency is less than 2%, which meets the target requirements. The research results can provide a research and development basis for designing high-performance centrifugal air compressors for fuel cell vehicles.

Renewable fuel-powered micro-gas turbine and hydrogen fuel cell systems: Exploring scenarios of technology, control, and operation

Two technology options, a proton exchange membrane (PEM) fuel cell and a recuperated micro-gas turbine (MGT) consisting of equipment with variable efficiencies and a controllable bypass valve, are modeled numerically. The validated simulations are studied under multiple scenarios, including technology, control, and operation. Under the technology scenario, the PEM fuel cell depicts higher net heat energy (1390.5 kW) with an overall efficiency of 93.27 %, significantly reducing thermal dissipation compared to the MGT, which has a low heat-to-power ratio (0.69) with the same hydrogen combustion rate (0.018 kg s−1). Following the fuel scenario, at 40 %-part load and 100 % bypass valve position, the highest net power (137.08 kW) and heat generation (635.07 kW) are achieved when 0.009 kg s−1 of hydrogen is combusted in MGT, exceeding other fuel utilization. In addition, the heating control strategy determines the availability status of the proposed technologies. The observed operational trends indicate effective fulfillment of urban heating needs by hydrogen combustion during Winter and Fall. However, the utilization of biogas leads to significant functional limitations. Finally, the operating function of the PEM fuel cell under off-design conditions is evaluated, resulting in notable enhancements in energy outputs and hydrogen consumption when considering the combination of control parameters compared to their individual evaluations.

Simulation analysis of BOP thermal management system for hydrogen fuel cell bus

Hydrogen fuel cell bus has been rapidly developed. As an important part of the hydrogen fuel cell system, its BOP (Balance of plant) mainly includes air compressor, controller, and intercooler. In practical applications, the BOP thermal management system generally includes separated cooling circuits. This study proposes an integrated BOP thermal management system, in which the air compressor, the controller and the intercooler share the same cooling circuit. A 1-D numerical model is built in this paper. On the basis of the model, the 13 possible layout schemes of cooling circuit are investigated. Additionally, the BOP temperature variation characteristics under the UDDS (Urban Dynamometer Driving Schedule) condition are also analyzed. The results indicate that not all layouts of integrated scheme can meet the cooling requirements. To meet cooling requirements of the whole BOP, the coolant should pass through the intercooler first in the serial schemes. As for the parallel schemes, the air compressor should be in a single branch, and the controller and the intercooler should be in series successively at another branch. Under the same total flow rate, the average temperature of BOP in the series scheme can be lower than that in parallel scheme by 8 %. In the three components, the intercooler is most affected by the stack power. This study provides reference for the design of the BOP thermal management system.

Optimal performance and preliminary parameter matching for hydrogen fuel cell powertrain system of electric aircraft

Fuel cells are true net-zero carbon emission power sources for aircraft, which is highly sensitive to weight. In the initial phase of adapting hydrogen fuel cell systems for aircraft powertrains, preliminary design parameter matching remains premature. An explicit method for the performance optimization of aircraft hydrogen fuel cell powertrain systems and a process of preliminary parameter matching are proposed to address this problem. Performance and weight models of the fuel cell stack and its auxiliaries, the cathode air compressor subsystem, and the cooling subsystem are designed, and system performance at various altitudes and power output levels is calculated. The aircraft flight mission performance is synthesized and considered in the optimization process. The optimization result of system performance and the corresponding design parameters are then graphically illustrated as tern plots. Unlike the traditional iterative preliminary system parameter matching and optimization method, which explores the design space non-directionally and converges to a single local optimal point, the proposed explicit method sweeps the design space globally and obtains a group of design points with acceptable optimality. The system design process is boosted by a compact iterative loop. In the optimization practice, the cruise powertrain specific energy is improved by 6.5%. The relationship between specific system design parameters and system performance is displayed globally by the resulting tern plots. Multiple design guidelines are observed and proposed, and design scenarios are directly obtained from the graphs for further engineering processes.

Techno-economic and environmental analysis for the application of renewable energy sources in seaports.

Ports have an indisputable effect on the decarbonization of urban areas, helping to minimize air and environmental pollution and achieve sustainable development. In this instance, it is crucial to do research that can advance our understanding of how to increase ports' energy independence by utilizing renewable energy sources. The current study aims to study the environmental benefits and techno-economic challenges of converting three Egyptian ports to eco-friendly green ports by using solar panels, offshore wind turbines, and hydrogen fuel cells. The study shows that from a technical point of view, the required green power to be installed at Alexandria, Port Said, and Suez ports is around 13 MW, 5 MW, and 1.5 MW, respectively. Furthermore, the environmental analysis findings demonstrate that integrating green energy will significantly lower emissions in seaports. It is anticipated that the ports of Alexandria, Port Said, and Suez will achieve annual reductions in carbon dioxide emissions of roughly 68,7 k-tons, 25,8 k-tons, and 6,4 k-tons, respectively. From an economic point of view, the ports could be supplied with green energy from wind turbines for a cost of between 0.115 and 0.125 USD/kWh, while solar panels have a cost range of 0.098 to 0.129 USD/kWh. Additionally, hydrogen fuel cell systems cost about 0.102 USD/kWh.

Application of renewable energy systems in seaports towards sustainability and decarbonization: Energy, environmental and economic assessment

The application of green energy technologies to supply berthed ships in ports with the necessary power instead of using their diesel generators is considered an initiative towards sustainability and climate change mitigation. Therefore, the current paper investigates the implementation of solar panels, offshore wind turbines, and hydrogen fuel cell systems as green technologies to supply the berthed ships with power in three Egyptian ports. The power requirements are determined by analyzing the annual ship traffic data and estimating the energy demand for each ship type. As a relevant result, the annual energy demand for ships berthed in Alexandria, Damietta, and Safaga ports is about 44.2 × 103 MWh, 22 × 103 MWh, and 5.6 × 103 MWh, respectively. The analysis results reveal a potential annual carbon dioxide reduction of 31.7 k-tons, 15.7 k-tons, and 4.2 k-tons in Alexandria, Damietta, and Safaga ports, respectively. From an economic perspective, the levelized cost of energy (LCOE) of solar panels is estimated to be 80.7–90.1 $/MWh, while hydrogen fuel cells have a cost of 166.8–172 $/MWh. On the other hand, LCOE in the case of wind turbines is estimated to be 140.8 $/MWh for Alexandria ports, 178.3 $/MWh for Damietta port, and 103.9 $/MWh for Safaga port.

An Optimization Approaches and Control Strategies of Hydrogen Fuel Cell Systems in EDG-Integration Based on DVR Technology

An Optimization Approaches and Control Strategies of Hydrogen Fuel Cell Systems in EDG-Integration Based on DVR Technology

Net-zero energy management through multi-criteria optimizations of a hybrid solar-hydrogen energy system for a laboratory in Toronto, Canada

Hydrogen production and storage in hybrid systems is a promising solution for sustainable energy transition, decoupling energy generation from demand and boosting the deployment of renewable energy. Nonetheless, the optimal and cost-effective design of hybrid hydrogen-based systems is crucial to tackle existing limitations in the diffusion of these systems. The present study explores net-zero energy management via a multi-objective optimization algorithm for an outdoor test facility equipped with a hydrogen-based hybrid energy production system. Aimed at enabling efficient integration of hydrogen fuel cell system, the proposed solution attempts to maximize the renewable factor (RF) and carbon mitigation in the hybrid system as well as to minimize the grid dependency and the life cycle cost (LCC) of the system. In this context, the techno-enviro-economic optimization of the hybrid system is conducted by employing a statistical approach to identify optimal design variables and conflictive objective functions. To examine interactions in components of the hybrid system, a series of dynamic simulations are carried out by developing a TRNSYS code coupled with the OpenStudio/EnergyPlus plugin. The obtained results indicate a striking disparity in the monthly RF values as well as the hydrogen production rate, and, therefore, in the level of grid dependency. It is shown that the difference in LCC between optimization scenarios suggested by the design of experiments could reach $15,780, corresponding to 57 % of the mean initial cost. The LCOE value yielded for optimum scenarios varies between 0.389 and 0.537 $/kWh. The scenario with net-zero target demonstrates the lowest LCOE value and the highest carbon mitigation, i.e., 828 kg CO2/yr, with respect to the grid supply case. However, the LCC in this scenario exceeds $57,370, which is the highest among all optimum scenarios. Furthermore, it was revealed that the lowest RF in optimal scenarios is equal to 66.2 % and belongs to the most economical solution.

An Optimization Approaches and Control Strategies of Hydrogen Fuel Cell Systems in EDG-Integration Based on DVR Technology

An Optimization Approaches and Control Strategies of Hydrogen Fuel Cell Systems in EDG-Integration Based on DVR Technology

A Study on the Thermal Behavior of Series and Parallel Connection Methods in the Process of Hydrogenation of Ship-Borne Hydrogen Storage Cylinder

As a subdivision of the hydrogen energy application field, ship-borne hydrogen fuel cell systems have certain differences from vehicle or other application scenarios in terms of their structural type, safety, environmental adaptability, and test verification. The connection method of the ship-borne hydrogen storage cylinder (SHSC) is very important for the hydrogen fuel cell ship, and the structural parameters of the SHSC are particularly important in the hydrogen refueling process. To ensure the safe and reliable operation of the hydrogen-powered ship, research on the filling of the SHSC under different connection modes was carried out during refueling. In our study, a thermal flow physical model of the SHSC was established to research the hydrogen refueling process of the series and parallel SHSCs. The influence of series and parallel modes of the SHSCs on the hydrogen refueling process was explored, and the evolution law of the internal flow field, pressure, and temperature of series and parallel SHSCs under different filling parameters was analyzed by numerical simulation. Our results confirmed the superiority of the parallel modular approach in terms of thermal safety during refueling. The results can supply a technical basis for the future development of hydrogen refueling stations and ship-board hydrogenation control algorithms.

A Review of the Research Progress and Application of Key Components in the Hydrogen Fuel Cell System

The hydrogen cycle system, one of the main systems used for hydrogen fuel cells, has many advantages. It can improve the efficiency, the water capacity, and the management of thermal fuel cells. It can also enhance the safety of the system. Therefore, it is widely used in hydrogen fuel cell vehicles. We introduce the structure and principles of hydrogen cycle pumps, ejectors, and steam separators and analyze and summarize the advantages of the components, as well as reviewing the latest research progress and industrialization status of hydrogen cycle pumps and ejectors. The technical challenges in hydrogen circulation systems and the development direction of key technologies in the future are discussed. This paper aims to provide a reference for research concerning hydrogen energy storage application technology in hydrogen fuel cell systems.

Potential of Proton-Exchange Membrane Fuel-Cell System with On-Board O2-Enriched Air Generation

Hydrogen fuel-cell systems are one of the alternatives for the decarbonization of the transportation sector. In such systems, the usage of O2-enriched air has the potential to improve fuel cell performance as well as to reduce degradation phenomena linked to local O2 starvation. However, the production of an O2-enriched air stream implies energy consumption that needs to be evaluated in the overall system efficiency. In this study, the potential of a system including polymeric membranes for O2-N2 separation to produce O2-enriched air was evaluated theoretically. First, the balance of plant, including the O2-N2 separation membrane and a two-stage boosting system, was considered. Two sources of energy recovery were identified: a high-pressure H2 stream and retentate flow (N2-rich) at the outlet of the separation membrane. Then, the efficiency of the system was evaluated for different levels of O2 enrichment, with sensitivities to the main operational and design parameters, i.e., cathode excess O2 ratio, turbomachinery efficiency, essure ratios. The results show the potential for an O2-enriched system if the energy recovered reaches approximately 25% of the additional power consumption induced by the separation membrane.

Model Based Controller Design for Hydrogen Fuel Cell Systems

In this paper, fuel cell system modelling alongside controller development for performance improvements, are investigated. Essentially and in general terms there are two approaches to modelling; black box modelling and detailed dynamic modelling. This work addresses both modelling approaches. These models are then used for hydrogen fuel cell (FC) controller development for improved system performance. A fuzzy-PID hybrid controller has been designed and tested and the results indicate that the fuzzy-PID hybrid control strategy can improve the system’s performance significantly.

An Optimization Model for the Optimal Control of the Oxygen Excess Ratio in a Hydrogen Fuel Cell System

This paper focuses on the control of a fuel cell system, for which an optimization model is proposed to control the oxygen excess ratio in order to tackle the fuel cell starvation phenomenon and increase the net power production of the system. The optimization problem considers the detailed nonlinear dynamics of the stack and the air supply sub-system as constraints and upper and lower bounds to consider the technical limitations in the system’s operation. The goal is to maintain the oxygen excess ratio at its reference value, using the compressor input voltage as a control variable, under several load variations of the current demand, considered as the external noise to the system. The proposed nonlinear optimization problem has been applied to a 75 kW stack used in the Ford P2000 fuel cell prototype vehicles, and results have been compared to the proportional-integral (PI) control technique. The proposed control approach has shown a significant enhancement in the control performance of the oxygen excess ratio.

A new design method for the vortex hydrogen circulating pump system

Against the backdrop of “carbon peak and carbon neutrality,” the hydrogen and fuel cell vehicle industry are rapidly developing. Within the on-board hydrogen supply system, the hydrogen circulation pump serves as an essential component of the hydrogen fuel cell system. The spiral disk, as a core part of the hydrogen fuel cell system’s vortex hydrogen circulation pump (VHCP), plays a crucial role in determining the performance of the hydrogen circulation system in hydrogen fuel cell vehicles. To meet the requirements for high-performance and high-reliability development of the hydrogen circulation pump, the VHCP scheme is adopted as the choice for the hydrogen pump solution. Through the magnetic suspension and no connection shaft structural design, the feasibility of applying the high speed and high flow hydrogen turbine was initially validated. Utilizing Fluent analysis software and high precision performance test bench, a comprehensive three-dimensional numerical simulation of the turbine design under various operating conditions was conducted and performance test verification, demonstrating that the performance meets the required specifications. By conducting research in both strength optimization design and performance requirement, two major technical challenges in turbine pump application were overcome. Combined with the experimental results of the turbine medium, it is concluded that the vortex pump can meet the flow and pressure rise under the premise of low power consumption in the hydrogen circulation system so as to perfectly increase the hydrogen return amount. Based on these findings, recommendations are proposed for the future development direction of hydrogen supply systems in hydrogen fuel cell vehicles.

Methods for Estimating Hydrogen Fuel Tank Characteristics

Abstract The pressure vessels needed to store hydrogen for next-generation hydrogen fuel cell vehicles are expected to be a substantial portion of the total system mass, volume, and cost. Gravimetric capacity, volumetric capacity, and cost per kilogram of usable hydrogen are key performance metrics that the U.S. Department of Energy (DOE) uses to determine the viability of hydrogen fuel cell systems. Research and development related to hydrogen storage systems covers a wide range of potential operating conditions, from cryogenic temperatures to high temperatures (above ambient) and low pressure to high pressure. Researchers at PNNL have developed methods for estimating these key pressure vessel characteristics to support on-board hydrogen storage system design and performance evaluation and to support decision-making about DOE hydrogen storage system research investments. This article describes the pressure tank estimation methodology that has been used as a stand-alone calculation and has been incorporated into larger system evaluation tools. The methodology estimates the geometry, mass, and material cost of type I, type III, and type IV pressure vessels based on operating pressure and material strength at the system's operating temperature, using classical thin-wall and thick-wall pressure vessel stress calculations. The geometry, mass, and material cost requirements of the pressure vessel have significant impacts on the total system performance. For example, hydrogen storage materials that can separately achieve a very high hydrogen density can be deemed impractical for use in fuel cell vehicle hydrogen storage systems because the pressure tank containing them is too large, heavy, or expensive. This article describes the design philosophy and analytical process of the tank characteristic estimation methodology, which has been implemented in spreadsheet calculation tools and system-level analysis tools used by DOE researchers. Each of the three tank types (type I, type III, and type IV) uses a different analysis methodology with some common elements. This article also provides examples of implementing the methodology to perform parametric studies of all three pressure vessel types. The goal of this article is to present the methodology in sufficient detail so it can be implemented in other hydrogen fuel cell vehicle design and analysis tools.

AMESet 기반 20 kW급 수소 연료전지 시스템 동특성 모델 해석

AMESet 기반 20 kW급 수소 연료전지 시스템 동특성 모델 해석

Inherent safety assessment of on-board methanol reforming hydrogen production fuel cell system considering jet fire and vapor cloud explosion

The on-board methanol reforming hydrogen fuel cell system (MRFC) is considered more promising than hydrogen fuel cell vehicle. However, few studies have been conducted on the safety of this system. This study investigates the inherent safety of MRFC. An inherent safety assessment framework was established to assess the MRFC's inherent safety, considering jet fire and vapor cloud explosion (VCE). The analysis results show that the radiation intensity of the hot methanol stream was 135.0920 kW/m2 at 0.5 m when a jet fire occurred. The methanol tank had the most severe explosive consequence, which can affect up to 60 m. The study concludes that the streams around the reformer and the methanol tank pose high risks. Compared to other studies, this study quantifies the risks of MRFC's equipment and pipelines, providing a reference for the inherent safety design of integrated processes in the future.

Investigation of Nanoparticle Degradation in Hydrogen Fuel Cell Systems through Automated Electron Microscopy.

Investigation of Nanoparticle Degradation in Hydrogen Fuel Cell Systems through Automated Electron Microscopy.

Study of the influence under different operating conditions on the performance of hydrogen fuel cell system for a bus

In order to analyze the impact of operating conditions on the performance of hydrogen fuel cell systems and optimize the external operating conditions of fuel cells, this paper takes an electrically hybrid hydrogen fuel cell bus as the research object, adopts a data driven hydrogen fuel cell stack model, establishes a simulation model and performance simulation platform for the hydrogen fuel cell system, and analyzes the output characteristics of the hydrogen fuel cell stack under different temperatures, humidity, and stoichiometric ratios. It turns out that the optimum working temperature of the target stack is 61 ℃; When the target reactor is operated at the optimum operating temperature, humidification of cathode and anode can effectively improve the relative humidity distribution of MEA; The best stoichiometric ratio of the target reactor is λ = 2. The model obtains the optimal operating conditions.The results of this study provide a basis for setting the optimal operating parameters of this type of Hydrogen fuel cell system, and the research method also has reference significance for other Hydrogen fuel cell systems to set the target operating parameters.