Patent Publication Number: US-2007099045-A1

Title: Fuel cell device capable of adjusting operational parameters

Description:
FIELD OF THE INVENTION  
      The present invention relates to a fuel cell device, and more particularly, to a fuel cell device capable of adjusting operational parameters, which sets the operational conditions on the fuel cell device, monitors the operational records, and controls the performance of the fuel cell device.  
     BACKGROUND OF THE INVENTION  
      The assigned United States Patent Application Publication Number US2005/0158608A1, entitled “Method For Manufacturing a Layer Lamination Integrated Fuel Cell And The Fuel Cell Itself” discloses how to fabricate a fuel cell board by printed circuit board processes.  
      The conventional fuel cell has a cell core that performs electrochemical reactions and outputs power The performance of the cell core, such as output voltage/current, fuel temperature, fuel concentration, etc., is conducted by the cell core that performs electrochemical reactions with predetermined and unchangeable parameters. Presently, there is no efficient, reliable test system to follow the relationship between the performance of the fuel cell and the operational parameters thereof. Additionally, a test system is demanded to connect the performance and the operational parameters during the electrochemical reactions in the fuel cell, so as to control the performance of the fuel cell and to satisfy the experimental requirements for the developers of fuel cells.  
      Since it is essential to simulate and control the operations of a fuel cell, a fuel cell capable of adjusting operational parameters is needed.  
     SUMMARY OF THE INVENTION  
      It is a first object of the invention to provide a fuel cell device capable of adjusting operational parameters, to overcome the aforesaid disadvantages in the related prior art.  
      It is a second object of the invention to provide a fuel cell device capable of adjusting operational parameters, which sets the operational parameters of the fuel cell boards, tests and records the operational status of the fuel cell boards, and retrieves the information about the performance associated with the operational parameters of the fuel cell boards.  
      It is a third object of the invention to provide a fuel cell device capable of adjusting operational parameters. The fuel cell device uses the information about the operational status associated with the operational parameters to control its performance, and thereby the experimental requirements for the developers of fuel cells are met.  
      In accordance with the aforesaid objects of the invention, a fuel cell device capable of adjusting operational parameters is provided, which includes fuel cell boards, an anode regulator, a cathode regulator, an anodic fuel supplier, and a control circuit. The fuel cell boards include an electrically connected interface to communicate status signals generated by the fuel cell boards in operation. The anode regulator is connected to the anodic fuel inlets and the anodic fuel outlets of the fuel cell boards and provides anodic fuels with predetermined parameters. The cathode regulator adjusts an amount of cathodic fuels supplied for cathodes of the fuel cell boards. The anodic fuel supplier is connected to the anode regulator and contains anodic fuels. The control circuit receives the status signals from the fuel cell boards, controls the anodic fuel supplier and the anode regulator based on the status signals to make the concentration, flow rate and temperature of anodic fuels injected into the fuel cell boards meet predetermined parameters, and controls the cathodic fuel supplier based on the status signals to make the flow rate of cathodic fuels injected into the fuel cell boards meet predetermined parameters. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other modifications and advantages will become even more apparent from the following detained description of a preferred embodiment of the invention and from the drawings in which:  
       FIG. 1  illustrates the structure of a fuel cell device able to regulate operational parameters according to one embodiment of the invention; and  
       FIG. 2  shows the cross section of a gas-liquid separator in accordance with one embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  illustrates the structure of a fuel cell device able to adjust operational parameters according to one embodiment of the invention. The fuel cell device  10  capable of adjusting operational parameters utilizes one or more fuel cell boards  101  as power generators, controls over other related devices using a control circuit  102  to set or regulate the operational parameters of the fuel cell boards  101 , and constantly monitors the performance of all the fuel cell boards  101  in use.  
      The fuel cell device  10  capable of adjusting operational parameters includes at least one fuel cell board  101 , a control circuit  102 , an anode regulator  103 , a cathode regulator  104 , and an anodic fuel supplier  105 , which are separately described hereinafter. For clarifying the invention, a direct methanol fuel cell (DMFC) is illustrated in this embodiment; however, the structure disclosed in the invention may be applied to any other fuel cells with liquid anodic fuels.  
      The control circuit  102  includes a calculating controller (not shown). The control circuit  102  retrieves the information about the current temperature and current concentration of methanol solution  1034  through a first temperature sensor  1021  and a concentration meter  1022  disposed in a solution mixer  1031 . In addition, the control circuit  102  controls and manages a first pump  1032 , a second pump  1051  and a third pump  1052  to regulate the flow rate of fluids in and out of the pumps  1032 ,  1051  and  1052 .  
      The control circuit  102  further includes a communication interface (not shown) providing a means of coupling itself to an external electronic device (i.e. computer) for data exchange. The communication interface may be a USB communication interface, for example. The control circuit  102  also includes a voltage-regulated circuit (not shown) for regulating the output voltage from the fuel cell boards  101  to be constant. An exemplar of the control circuit  102  includes a printed circuit substrate with electronic components soldered thereon.  
      The anodic fuel supplier  105  includes, a water tank  1053 , an anodic fuel tank  1054 , a second pump  1051 , and a third pump  1052 . The water tank  1053  is a vessel for containing water. The source of water may be fresh water from the outside or recycled water  1043  from a condenser  1041 . The anodic fuel tank  1054  is a container for storing a methanol solution with high concentration, such as pure methanol. The second pump  1051  is provided to expel water  1055  in the water tank  1053  and to control the flow rate of water  1055 . The third pump  1052  is provided to propel a concentrated methanol solution  1056  within the anodic fuel tank  1054  and to control the flow rate of the concentrated methanol solution  1056 .  
      The pumps  1051  and  1052  may be replaced by check valves.  
      The anode regulator  103  includes a solution mixer  1031 , a first pump  1032  and a gas-liquid separator  1033 . The solution mixer  1031  is in the form of a vessel having outlets (not shown) respectively connected to the inlets (not shown) of the fuel cell boards  101 . The methanol solution  1034  inside the solution mixer  1031  is controlled by the control circuit  102  to have some predetermined parameters, such as predetermined concentration, temperature and flow rates. Only the methanol solution  1034  with predetermined parameters can be injected into the fuel cell boards  101 .  
      The first pump  1032  is positioned between the solution mixer  1031  and the gas-liquid separator  1033 . The first pump  1032  forces the methanol solution  1034  to pass through the fuel cell boards  101 , and recycles the anodic products/recycled aqueous solution of methanol  1011  to flow into the gas-liquid separator  1033 . Also, the first pump  1032  is provided to drive the recycled aqueous solution of methanol  1035  to the solution mixer  1031 .  
       FIG. 2  shows the cross section of a gas-liquid separator in accordance with one embodiment of the invention. The gas-liquid separator  1033  is a container, and a gas permeable but liquid impermeable membrane  1033   a  covers the opening of the container tightly. Each anodic fuel outlet (not shown) of the fuel cell board  101  is connected to the inlet  1033   b . The anodic products/recycled aqueous solution of methanol  1011  from the fuel cell boards  101  flow into the gas-liquid separator  1033  through the inlet  1033   b . Then, the gas permeable but liquid impermeable membrane  1033   a  separates the recycled aqueous solution of methanol  1035  from the anodic products (e.g. carbon dioxide) contained in the anodic products/recycled aqueous solution of methanol  1011 . The recycled aqueous solution of methanol  1035  inside the gas-liquid separator  1033  is pushed by the first pump  1032  such that the recycled aqueous solution of methanol  1035  flows towards the solution mixer  1031  through the outlet  1033   c.    
      The cathode regulator  104  includes a condenser  1041  and a fan  1042 . The fan  1042  causes external air to flow, and then provides air for the cathodes of the fuel cell boards  101 . The condenser  1041  is placed near the fan  1042  to collect steam out of the fuel cell boards  101  and to condense the steam as recycled water  1043 .  
      Furthermore, the fan  1042  is controlled by the control circuit  102 . As such, the airflow of external air induced by the fan  1042  is controllable. The flowing air not only supplies oxygen, but also radiates heat from the fuel cell boards  101  in operation. A second temperature sensor  1023  disposed around the fuel cell boards  101  is used to detect the environmental temperature. Thereby, the control circuit  102  may provide an adequate environmental temperature that favors the proceeding of electrochemical reactions in the fuel cell boards  101 .  
      The invention possesses one feature that the prior art lacks. That is, the fuel cell capable of regulating operational parameters can set various operational parameters so that the fuel cell board thereof generates power with the set parameters. In addition, the performance of the fuel cell board is controlled constantly, and every related operational parameter is adjusted dynamically.  
      While the invention has been particularly shown and described with reference to the preferred embodiments thereof, these are, of course, merely examples to help clarify the invention and are not intended to limit the invention. It will be understood by those skilled in the art that various changes, modifications, and alterations in form and details may be made therein without departing from the spirit and scope of the invention, as set forth in the following claims.