Water management subsystems

Research, develop, assemble, and test a 50 kW net polymer electrolyte membrane (PEM) fuel cell stack system comprised of a PEM fuel cell stack and the supporting gas, thermal, and water management subsystems. The PEM fuel cell stack system will be capable of integration with at least one of the fuel processors currently under development by Hydrogen Burner Technology (HBT) and Arthur D. Little, Inc. 

FCS water management is the key factor for an efficient and reliable operation of a PEMFC stack. Membrane hydration control and water balance for a durable operation of FCS are the main objectives of this sub-system, whose design and control issues, strictly connected to thermal management but also to reactant subsystem components, are discussed in Sect. 4.5. The possibility of interactions between the wet and warm cathode outlet stream and the components of thermal and water management sub-systems is also discussed. 

Figure 1 provides a schematic of the gasoline fuel cell power plant. The major subsystems include the Fuel Processing Subsystem, the Power Subsystem and the Balance of Plant. The Balance of Plant includes the Thermal Management Subsystem, the Air and Water Subsystems and the Controller and associated electrical equipment. 

While different developers are addressing improvements in individual components and subsystems in automotive fuel cell propulsion systems (e.g., cells, stacks, fuel processors, balance-of-plant components), we are using modeling and analysis to address issues of thermal and water management, design-point and part-load operation, and component-, system-, and vehicle-level eificiencies and fuel economies. Such analyses are essential for effective system integration. 

Nuvera will design, build, test, and deliver a 15 kilowatt electrical (kWe ) direct current (DC) fuel cell power module that will be specifically designed for stationary power operation using ethanol as a primary fuel. Two PEM fuel cell stacks in parallel will produce 250 amps and 60 volts at rated power. The power module will consist of a fuel processor, carbon monoxide (CO) clean-up, fuel cell, air, fuel, water, and anode exhaust gas management subsystems. A state-of-the-art control system will interface with the power system controller and will control the fuel cell power module under start-up, steady-state, transient, and shutdown operation. Temperature, pressure, and flow sensors will be incorporated in the power module to monitor and control the key system variables under these various operating modes. The power module subsystem will be tested at Nuvera and subsequently be delivered to the Williams Bio-Energy Pekin, Illinois site. 

The PEM fuel cell stack system consists of the fuel cell stack and supporting gas, thermal and water management systems as shown in Figure 1. Overall system performance depends on the careful integration of these subsystems. The system developed under this contract was designed to accept reformed gasoline from a fuel processor. Development of the fuel processor was not part of this program. 

Boryezko, K. Tchorzewska-CieSak, B., 2012. Maps of risk in water distribution subsystem. 11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference, 2012, Curran Associates, Inc.,p. 5832-5841. 

Water management is absolutely critical in PEM fuel cells, because it affects the overall power and efficiency of a system. For a PFSA-membrane-based PEM fuel cell operated at <90 °C, complicated humidifier subsystems are usually needed to humidify the feeding gases (H2 and O2 or air) to maintain... 

Regardless of the organization of the Data Acquisition and Archiving Subsystems, part of the information will come from automatic measurements of air and water pollution concentrations at a number of measurement stations, and from automatic water level gauges in individual river segments, which are of use for flood management. Because of considerable distances between measurement stations and data acquisition centers in this distributed system, the best solution for communication is a nationwide 2G cellular phone network, covering over 96% of the country s area. 

Table 10.1 shows variations in gas consumption rates, water production rate, and heat generation rate for different fuel cell stack power. As we can see, with increased power level, subsystems such as air and fuel delivery system, and water and heat management systems also scale up in size and complexity. 

In a fuel cell power system, the stack is integrated with a number of subsystems such as air supply system, fuel supply system, water removal and management cooling and heat management system and power supply management and control subsystem as shown in Figure 10.7. 

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