Papers by Keyword: Flow Channel

Abstract: As fossil fuels are becoming less reliable and more costly, the Proton Exchange Membrane Fuel Cell (PEMFC) is emerging as the primary candidate to replace the stationary and transport applications. In this study numerical simulation on PEMFC is done by commercially available Computational Fluid Dynamics (CFD) software. A three-dimensional, model of a single PEM Fuel cell with serpentine flow field design has been used for the study. The numerical model is 3-D steady, incompressible, single phase and isothermal includes the governing of mass, momentum, energy, and species along with electrochemical equations. All of these equations are simultaneously solved in order to get current flux density and H₂, O₂ and H₂O fractions along the flow field design.

Abstract: Throught translation and rotation method of coordinate axis, a problem of the dynamic thermal stress distribution on the two-dimensional section of a flow channel occupied filling medium was studied theoretically. A general analytical solution with related computional process was described in detailed. As an illustration sample, some numberical results are shown in the figure about the dynamical thermal stress distribution on the section of an elliptic flow channel occupied filling medium.

Abstract: A multiple physical finite elements to analyze software (COMSOL Multiphysics) is employed to investigate serpentine flow channels of a small proton exchange membrane fuel cell with power 0.5W. Distributions of the oxygen flow, the liquid water, and the electric current density in three different designed flow channels are simulated and compared. Results show that increasing the channel width is conducive to increase the oxygen flow and reduce the production of liquid water. It thus enhances the electric current density. However, it will reduce the oxygen flow, produce more liquid water, and depress the current density if the channel width is decreased.

Abstract: Dealing with a droplet on the flow channel of PEMFC, a mathematical model based on the force balance of the flow force, gravity and hysteresis tension is derived to address the expressions of the critical airflow velocity and the droplet radii. The results show that in the horizontal flow channel, the critical airflow velocity is hardly affected by the working temperature but decreasing with the increasing of operation pressure. The droplet removal capability can be enhance by increasing the tilt angle of the cell. For a small droplet, the operation pressure has an apparent effect on the airflow velocity, while for a droplet in the spontaneous departure area, this effect can be neglected.

Abstract: Proton exchange membrane fuel cell (PEMFC) has high power density and energy conversion efficiency. Bipolar plate is one of the key components of the proton exchange membrane fuel cell, not only affects the performance of the battery, but also affects the cost of the battery, which is become a bottlenecks. This paper introduces several common forms of the bipolar plate flow channel of the PEMFC, analyzes their advantages and disadvantages, and then some new type of flow channel type comes up after improvements on this basis, so the future development trend of fuel cells summed up is combined with bionics or using a complex flow field. An overview of the commonly used material and processing of the bipolar plate, respectively, graphite sheet, sheet metal and composite bipolar plates.

Abstract: The components of sheet metal FMS are abstracted corresponding eM-Plant object, the sheet metal FMS’s automatic guided vehicle system and parts management system are built in eM-Plant. Adjusting the system parameters in the model, several simulations obtained an ideal simulation result. These research show that, using eM-Plant software to build model and simulate for sheet metal FMS can save time, improve simulation result of sheet metal FMS.

Abstract: A non-linear flow channel implementation method in magnetic gap space of magneto-rheological valve is proposed in this paper. The involved magneto-rheological valve in the method has a non-line flow channel which is formed by magnetic gap space between oil inlet disc and oil distribution disc, the concentric annular trapezoidal concave of the surface of the oil inlet disc, the concentric annular trapezoidal convex of the surface of the oil distribution disc, the corresponding convex and concave trapezium between the inlet oil disc and the oil distribution disc, the surface of oil distribution disc and oil inlet disc. The method is beneficial, because the maximum magneto-rheological effect is produced by placing the magneto-rheological fluid in the magnetic field whose intensity is maximum and not more than magneto-rheological fluid saturation intensity, and the magneto-rheological fluid channel length is lengthen in the limited space of the magnetic gap, we can further poly-magnetic by using of separated magnetic sheeting under condition of taking full advantage a limited poly-magnetic cross-section of the magnetic field. The method can significantly enhance the magneto-rheological fluid pressure difference under the same magneto-rheological fluid and flow requirements, size requirements, response time requirements and energy requirements.

Abstract: Due to lack of desirable mechanical properties of silicon substrate; the current trend of micro-fabrication technology is towards metallic materials. In this study, the electrochemical micromachining (EMM) technology is developed to fabricate micro-scale flow channels on thin metallic 316L stainless steel plate. The cathode electrode, the tool, is the mirror image of flow channels. It was produced by the MEMS and UV-LIGA technology and the size is 200μm in width and 500μm in height for the intension to fabricate a serpentine flow channel of 200μm in both depth and width. Because of the electrode size, the process control parameters and geometrical features surpassed conventional and CMOS methods. The flow channels on 0.6mm thick SS 316L plates were fabricated by EMM process within 30 seconds with effective area of 625mm2. The dimensions of flow channel were varying from 1504m to 5004m in width and about 2004m in depth. The results demonstrate the EMM technology produces good quality metallic flow channels efficiently.