Control of a PEM Fuel Cell Cooling System

Author(s):  
Richard T. Meyer ◽  
Bin Yao

Previous research has assumed that a perfect Proton Exchange Membrane Fuel Cell (PEMFC) body temperature manager is available. Maintaining this temperature at a desired value can ensure a high reaction efficiency over all operation. However, fuel cell internal body temperature control has not been specifically presented so far. This work presents such control, using a Multiple Input Single Output (MISO) fuel cell cooling system to regulate the internal body temperature of a PEMFC intended for transportation. The cooling system plant is taken from a recently developed hydrogen/air PEMFC total system model. It is linearized and used to design a series of controllers via μ-synthesis. μ-synthesis is chosen since system nonlinearities can be handled as parameter uncertainties. A controller must coordinate the desired fuel cell internal temperature and commanded mass flow rates of the coolant and cooling air. Each linear controller is created for a segment of the expected current density range. Plant parameters are expected to vary over their linearized values in each segment. Also, a common set of μ-synthesis weighting functions has been developed to ease controller design at different operating points. Thus, the nonlinear cooling subsystem can be controlled with a series of current density scheduled linear controllers. Current density step change simulations are presented to compare the controller closed loop performance and open loop response which uses cooling system flow rates taken from an optimal steady state solution of the whole fuel cell system. Furthermore, a closed loop sinusoid response is also given. These show that the closed loop driven internal fuel cell temperature will vary little during operation. However, this will only be true over the range that the cooling system is required to be active.

2021 ◽  
Vol 248 ◽  
pp. 114800
Author(s):  
Quangang Xia ◽  
Tong Zhang ◽  
Yuan Gao ◽  
XiChen Ye ◽  
Ciming Guan

Author(s):  
Utku Gulan ◽  
Hasmet Turkoglu ◽  
Irfan Ar

In this study, the fluid flow and cell performance in cathode side of a proton exchange membrane (PEM) fuel cell were numerically analyzed. The problem domain consists of cathode gas channel, cathode gas diffusion layer, and cathode catalyst layer. The equations governing the motion of air, concentration of oxygen, and electrochemical reactions were numerically solved. A computer program was developed based on control volume method and SIMPLE algorithm. The mathematical model and program developed were tested by comparing the results of numerical simulations with the results from literature. Simulations were performed for different values of inlet Reynolds number and inlet oxygen mole fraction at different operation temperatures. Using the results of these simulations, the effects of these parameters on the flow, oxygen concentration distribution, current density and power density were analyzed. The simulations showed that the oxygen concentration in the catalyst layer increases with increasing Reynolds number and hence the current density and power density of the PEM fuel cell also increases. Analysis of the data obtained from simulations also shows that current density and power density of the PEM fuel cell increases with increasing operation temperature. It is also observed that increasing the inlet oxygen mole fraction increases the current density and power density.


Author(s):  
Munzer S. Y. Ebaid ◽  
Mohamad Y. Mustafa

The design of the fuel cell plays a major role in determining their cost. It is not only the cost of materials that increases the cost of the fuel cell, but also the manufacturing techniques and the need for skilled technicians for assembling and testing the fuel cell. The work presented in this paper is part of a research work aims to design and manufacture a proton exchange membrane (PEM) modular fuel cell of 100 W output at low cost using conventional materials and production techniques, then testing the fuel cell to validate its performance. This paper will be dealing only with the design of a modular fuel cell that can be mass produced and used to set up a larger fuel cell stack for stationary applications (6 kW) which is capable of powering a medium sized household. The design for 100 W fuel cell module will include the calculations for the main dimensions of the fuel cell components, mass flow rate of reactants, water production, heat output, heat transfer and the cooling system. This work is intended to facilitate material and process selection prior to manufacturing alternatives prior to capital investment for wide-scale production. The authors believe that the paper would lead to a stimulating discussion.


1999 ◽  
Author(s):  
C. Y. Wang ◽  
Z. H. Wang ◽  
Y. Pan

Abstract Proton exchange membrane (PEM) fuel cells have emerged, in the last decade, as a viable technology for power generation and energy conversion. Fuel cell (FC) engines for vehicular applications possess many attributes such as high fuel efficiency, low emission, quiet and low temperature operation, and modularity. An important phenomenon limiting fuel cell performance is the two-phase flow and transport of fuel and oxidant from flow channels to reaction sites. In this paper a mathematical model is presented to study the two-phase flow dynamics, multi-component transport and electrochemical kinetics in the air cathode, the most important component of the hydrogen PEM fuel cell. A major feature of the present model is that it unifies single- and two-phase analyses for low and high current densities, respectively, and it is capable of predicting the threshold current density corresponding to the onset of liquid water formation in the air cathode. A numerical study based on the finite volume method is then undertaken to calculate the detailed distributions of local current density, oxygen concentration, water vapor concentration and liquid water saturation as well as their effects on the cell polarization curve. The simulated polarization curve and predicted threshold current density corresponding to the onset of liquid water formation for a single-channel, 5cm2 fuel cell compare favorably with experimental results. Quantitative comparisons with experiments presently being conducted at our laboratory will be reported in a forthcoming paper.


2019 ◽  
Vol 969 ◽  
pp. 461-465
Author(s):  
Matha Prasad Adari ◽  
P. Lavanya ◽  
P. Hara Gopal ◽  
T.Praveen Sagar ◽  
S. Pavani

Proton exchange membrane fuel cell (PEMFC) system is an advanced power system for the future that is sustainable, clean and environmental friendly. The flow channels present in bipolar plates of a PEMFC are responsible for the effective distribution of the reactant gases. Uneven distribution of the reactants can cause variations in current density, temperature, and water content over the area of a PEMFC, thus reducing the performance of PEMFC. By using Serpentine flow field channel, the performance is increased. Two types of serpentine flow field channels are implemented such as curved serpentine flow field channel and normal serpentine flow field channels. The result shows that curved serpentine flow field channel gives better current density and power density, thus increasing the performance of PEMFC.


Author(s):  
Tao Zhang ◽  
Pei-Wen Li ◽  
Qing-Ming Wang ◽  
Laura Schaefer ◽  
Minking K. Chyu

Two types of miniaturized PEM fuel cells are designed and characterized in comparison with a compact commercial fuel cell device in this paper. One has Nafion® membrane electrolyte sandwiched by two brass bipolar plates with micromachined meander-like gas channels. The cross-sectional area of the gas flow channel is approximately 250 by 250 (μm). The other uses the same Nafion® membrane and anode structure, but in stead of the brass plate, a thin stainless steel plate with perforated round holes is used at cathode side. The new cathode structure is expected to allow oxygen (air) being supplied by free-convection mass transfer. The characteristic curves of the fuel cell devices are measured. The activation loss and ohmic loss of the fuel cells have been estimated using empirical equations. Critical issues such as flow arrangement, water removing and air feeding modes concerning the fuel cell performance are investigated in this research. The experimental results demonstrate that the miniaturized fuel cell with free air convection mode is a simple and reliable way for fuel cell operation that could be employed in potential applications although the maximum achievable current density is less favorable due to limited mass transfer of oxygen (air). The relation between the fuel cell dimensions and the maximum achievable current density is also discussed with respect to free-convection mode of air feeding.


Sign in / Sign up

Export Citation Format

Share Document