Balancing Stack, Air Supply, and Water/Thermal Management Demands for an Indirect Methanol PEM Fuel Cell System

2001 ◽  
Author(s):  
David J. Friedman ◽  
Anthony Eggert ◽  
P. Badrinarayanan ◽  
Joshua Cunningham
Keyword(s):  
Fuel Cell ◽  
Thermal Management ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Fuel Cell System ◽  
Air Supply

A Thermal Management System for a PEM Fuel Cell System in Commercial Vehicles

2010 ◽  
Author(s):  
Jong-Woo Ahn ◽  
Song-Yul Choe
Keyword(s):  
Fuel Cell ◽  
Thermal Management ◽  
Management System ◽  
Pem Fuel Cell ◽  
Cell System ◽  
State Feedback Control ◽  
Fuel Cell System ◽  
Commercial Vehicles ◽  
Coolant Pump ◽  
Thermal Management System

Polymer electrolyte membrane (PEM) fuel cell operating in commercial vehicles produces a relatively high amount of heat. In order for securing durable operations, the produced heat should be rejected to keep the temperature in the cell under the limit. High temperature increases the rate of electrochemical reactions and mobility of water vapor. However, a thermal stress imposing on the thin layers of catalysts and membranes can accelerate degradation processes. Therefore, proper design of a thermal management system (TMS) and the associated control is required for ensuring highly reliable and efficient operations of the system. A typical thermal circuit consisting of a radiator, a fan, a reservoir and a coolant pump has been used to reject the excessive heat from the fuel cell. However, the capability of heat rejection is limited by sizes of the components that cannot be employed in heavy duty vehicles. In this study, we used two coolant loops, where the inner circuit consists of a bypass valve, a heat exchanger, a reservoir and a water pump and the outer circuit includes a radiator, a fan, a reservoir and a coolant pump. A state feedback control for the two loops was designed. Objectives for the controls were to maintain the temperature at the set value and to reduce the parasitic loss of the system. The controllers were tested on a dynamic model of a stack developed in the laboratory. Included is analysis of dynamic performance of the designed controllers at multiple step currents and FUDS. As a result of the proposed thermal management system, the size of radiator and the capacity of the pumps for proposed design become 10% smaller than those for the typical one. In addition, the overall net power of the fuel cell system increases to 5%.

Design of Air, Water, Temperature and Hydrogen Controls for a PEM Fuel Cell System

2011 ◽  
Author(s):  
Jong-Woo Ahn ◽  
Jinglin He ◽  
Song-Yul Choe
Keyword(s):  
Fuel Cell ◽  
Thermal Management ◽  
State Feedback ◽  
Cell System ◽  
Supply System ◽  
Water Flooding ◽  
Fuel Cell System ◽  
Air Supply ◽  
Bypass Valve ◽  
Oxygen Excess

Polymer electrolyte membrane (PEM) fuel cell is the potential power source for vehicle applications, where supply of fuels and rejection of heat play significant roles in ensuring performance and durability. Operations of the fuel cells require four subsystems, air supply system, water and thermal management and hydrogen delivery system. Air supply system consists of a blower and a gas-to-gas humidifier. The air is supplied to the stack by the blower and humidified by a gas-to-gas humidifier using stack exhaust gas. Controls for the air supply system are designed based on a static feed-forward control and a state feedback control with integrator to maintain the oxygen excess ratio at a desired level regardless of any load applied. Flow rates of air controlled by a voltage of an electric motor driving a blower should be able to supply oxygen to dynamically follow changes of loads, whereby oxygen excess rate should be kept at a level that prevents oxygen starvation. At the same time, water in the stack should be maintained optimally to keep from low proton conductivity and water flooding in porous materials. Therefore, supplying air is humidified with a humidifier that captures moistures exiting the stack. In order to manipulate the amount of humidity, we propose to use an extra bypass valve, which opening is controlled to optimally maintain humidification of the membrane and avoid water flooding. Thermal management system consists of two thermal circuits because of cooling effectiveness, where the inner thermal circuit is made of a bypass valve, a heat exchanger, a water reservoir and a water pump, while the outer thermal circuit is made of a radiator along with a fan, a coolant reservoir and a pump. In order to maintain the stack working temperature at a desired temperature and reduce parasitic powers, a state feedback controller with integrator is employed. Fuel delivery system is a hybridized one that consists of two recirculation lines with an ejector and a blow in order to increase efficiency of fuel usage. The supply line is made of a hydrogen tank, a flow control valve and a low pressure regulator. Controls are designed to track a flow rate where pressure is kept at constant and purging operations are allowed. In this paper, controls for four subsystems of fuel cell system were proposed and examined on a dynamic one dimensional model for a stack that considers non isothermal and two-phase effects. Optimized state feedback controllers with integrator and observers are used to improve control performances and results are presented.

scholarly journals Balanced version of Slime Mold Algorithm: A study on PEM fuel cell system parameters identification

2021 ◽  
Vol 7 ◽  
pp. 3199-3209
Author(s):  
Junlong Zheng ◽  
Yujie Xie ◽  
Xiaoping Huang ◽  
Zhongxing Wei ◽  
Bahman Taheri
Keyword(s):  
Fuel Cell ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Slime Mold ◽  
Parameters Identification ◽  
Fuel Cell System ◽  
System Parameters
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