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US 7,087,326 B2Granted
Moisture sensor and fuel cell system using same
AssigneeDenso Corporation
InventorsTomonori Imamura, Toshiyuki Kawai
Life of this patent
Estimating the term…
Abstract
A moisture sensor working to measure a moisture content of a specified measurement gas is provided which consists of an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas and a controller. The electrochemical cell outputs an electrical energy arising from chemical reaction of the measurement gas with the reference gas. The controller controls at least one of voltage appearing across and current flowing through the electrochemical cell and uses one of them to measure the moisture content of the measurement gas. This enables the moisture content to be determined free from the humidify of the measurement gas.
Claims18
A fuel cell system, comprising:
- a moisture sensor working to measure a moisture content of a measurement gas, said moisture sensor including (a) an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas, said electrochemical cell outputting an electrical energy arising from chemical reaction of the measurement gas with the reference gas, (b) a voltage detector working to measure a voltage appearing at said electrochemical cell, (c) a current detector working to measure a current produced by said electrochemical cell, and (d) a controller controlling at least one of the voltage and the current of said electrochemical cell, said controller determining the moisture content of the measurement gas using one of the voltage and the current and providing a signal indicative thereof;
- a fuel cell producing an electrical energy through chemical reaction between hydrogen and oxygen;
- a moisture controlling mechanism working to control a quantity of moisture within said fuel cell;
- and
- a system controller working to determine a moisture condition within said fuel cell using the signal outputted from said moisture sensor, said system controller actuating said moisture controlling mechanism to control the quantity of moisture within said fuel cell to a desired value based on the determined moisture condition, wherein the measurement gas and the reference gas are identical in kind with each other, and wherein said controller works to bring a potential difference between the first and second electrodes of said moisture sensor to a given potential difference and determines that the quantity of moisture within said fuel cell is excessive when the current produced by the electrochemical cell is smaller than a first preselected current value.
2 more elements
A fuel cell system, comprising:
- a moisture sensor working to measure a moisture content of a measurement gas, said moisture sensor including (a) an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas, said electrochemical cell outputting an electrical energy arising from chemical reaction of the measurement gas with the reference gas, (b) a voltage detector working to measure a voltage appearing at said electrochemical cell, (c) a current detector working to measure a current produced by said electrochemical cell, and (d) a controller controlling at least one of the voltage and the current of said electrochemical cell, said controller determining the moisture content of the measurement gas using one of the voltage and the current and providing a signal indicative thereof;
- a fuel cell producing an electrical energy through chemical reaction between hydrogen and oxygen;
- a moisture controlling mechanism working to control a quantity of moisture within said fuel cell;
- and
- a system controller working to determine a moisture condition within said fuel cell using the signal outputted from said moisture sensor, said system controller actuating said moisture controlling mechanism to control the quantity of moisture within said fuel cell to a desired value based on the determined moisture condition, wherein the measurement gas and the reference gas are different in kind from each other, and wherein said controller works to bring the voltage of the electrochemical cell to a given voltage and determines that the quantity of moisture within said fuel cell is excessive when the current produced by the electrochemical cell is smaller than a first preselected current value.
2 more elements
A fuel cell system, comprising:
- a moisture sensor working to measure a moisture content of a measurement gas, said moisture sensor including (a) an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas, said electrochemical cell outputting an electrical energy arising from chemical reaction of the measurement gas with the reference gas, (b) a voltage detector working to measure a voltage appearing at said electrochemical cell, (c) a current detector working to measure a current produced by said electrochemical cell, and (d) a controller controlling at least one of the voltage and the current of said electrochemical cell, said controller determining the moisture content of the measurement gas using one of the voltage and the current and providing a signal indicative thereof;
- a fuel cell producing an electrical energy through chemical reaction between hydrogen and oxygen;
- a moisture controlling mechanism working to control a quantity of moisture within said fuel cell;
- and
- a system controller working to determine a moisture condition within said fuel cell using the signal outputted from said moisture sensor, said system controller actuating said moisture controlling mechanism to control the quantity of moisture within said fuel cell to a desired value based on the determined moisture condition, wherein the measurement gas and the reference gas are different in kind from each other, and wherein said controller determines that the quantity of moisture within said fuel cell is excessive when a value of the voltage of the electrochemical cell under control in which the current flowing through the electrochemical cell is kept at a given current value is smaller than a first preselected voltage value.
2 more elements
A fuel cell system, comprising:
- a moisture sensor working to measure a moisture content of a measurement gas, said moisture sensor including (a) an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas, said electrochemical cell outputting an electrical energy arising from chemical reaction of the measurement gas with the reference gas, (b) a voltage detector working to measure a voltage appearing at said electrochemical cell, (c) a current detector working to measure a current produced by said electrochemical cell, and (d) a controller controlling at least one of the voltage and the current of said electrochemical cell, said controller determining the moisture content of the measurement gas using one of the voltage and the current and providing a signal indicative thereof;
- a fuel cell producing an electrical energy through chemical reaction between hydrogen and oxygen;
- a moisture controlling mechanism working to control a quantity of moisture within said fuel cell;
- and
- a system controller working to determine a moisture condition within said fuel cell using the signal outputted from said moisture sensor, said system controller actuating said moisture controlling mechanism to control the quantity of moisture within said fuel cell to a desired value based on the determined moisture condition, wherein the measurement gas and the reference gas are different in kind from each other, and wherein said controller determines said fuel cell lacks in moisture content thereof when a value of the voltage of the electrochemical cell under control in which the current flowing through the electrochemical cell is kept at a given current value is greater than a second preselected voltage value.
2 more elements
A fuel cell system comprising:
- a fuel cell stack including a plurality of cells each of which is made up of a pair of collection members and an electrolyte film disposed between the collection members;
- a moisture sensor working to measure a quantity of moisture within at least one of the cells and output a signal indicative thereof;
- a moisture controlling mechanism working to control a moisture content of said fuel cell stack;
- and
- a system controller working to determine a moisture condition within said fuel cell stack using the signal outputted from said moisture sensor, said system controller actuating said moisture controlling mechanism to control the quantity of moisture within said fuel cell stack to a desired value based on the determined moisture condition,
- wherein said moisture sensor includes (a) an electrochemical cell having electrodes formed by portions of the pair of collection members of the cell and said electrolyte film and (b) a resistance measuring circuit working to measure a resistance value of said electrochemical cell, and wherein the quantity of moisture within the cell is determined as a function of the resistance value of said electrochemical cell.
3 more elements
Dependencies are inferred from the claim text.