KR20040009647A - Non-utility generator system and control method thereof - Google Patents

Abstract

PURPOSE: A self-generation system and a method for controlling the system are provided, to reduce the waste of the electric power and the fuel supplied to a fuel cell by supplying the electric power with a charger. CONSTITUTION: The self-generation system employs a fuel cell comprising a reformer(12) which generates hydrogen from the supplied fuel and contains a burner(12b) inside; a stack(13) which comprises a fuel electrode(13b) where the hydrogen of hydrogen-containing gas generated at the reformer is supplied, an air electrode(13c) where oxygen or an oxygen-containing oxidizing agent is supplied and an electrolyte membrane(13a) placed between the two electrodes, and generates the electricity and the heat by the electrochemical reaction of hydrogen and oxygen; and at least one charger(21, 22) which is connected with the stack to charge the electricity generated at the stack, and supplies the charged electricity to the external part and stops the operation of the fuel cell when the charging is finished.

Description

Self-generating system and its control method {NON-UTILITY GENERATOR SYSTEM AND CONTROL METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-generating system and a control method thereof, comprising a charger for charging electricity generated by operating a fuel cell, and supplying power to the charger, thereby wasting power and waste of fuel supplied to the fuel cell. The present invention relates to a self-generating system and a control method thereof.

In general, a fuel cell used in a self-power generation system is a device that directly converts energy contained in a fuel into electrical energy. A pair of electrodes including an anode and a cathode is disposed with an electrolyte interposed therebetween. In addition, the anode (oxide electrode or fuel electrode) is contacted with hydrogen or a fuel gas containing hydrogen, while the other cathode (reduction electrode or cathode) is contacted with an oxidizing gas containing oxygen and ionized in the process. It is a system that obtains both electricity and heat through the electrochemical reaction of fuel gas and oxidized gas.

As shown in FIG. 1, the self-power generation system using the fuel cell includes a fuel tank 1 filled with gasoline or other hydrocarbon (LNG, LPG, CH ₃ OH ...) fuel, and the fuel tank ( A reformer 2 for producing hydrogen from fuel supplied and connected to 1), and an oxidation reaction of hydrogen generated from the reformer 2 and a reduction reaction of oxygen supplied separately from the reformer 2. At the same time, a stack 3 which generates electricity and heat together, a converter 4a connected to the stack 3 and converting the electricity obtained from the stack 3 into an alternating current electricity, which is a commercial electricity, and A power converter 4 composed of an inverter 4b is provided.

In the figure, 2a is a reactor, 2b is a burner, 3a is an electrolyte membrane, 3b is a fuel electrode, 3c is a cathode, 6 is a feed water pump, and 7 is a humidifier.

A schematic process of generating electricity using the fuel cell of the conventional structure as described above is as follows.

That is, after the gasoline or hydrocarbon-based fuel flows into the reactor 2a of the reformer 2 from the fuel tank 1 by the controller (not shown), the fuel filled in the reactor 2a The steam and oxygen are supplied, and the burner 2b of the reformer 2 is operated to perform a reforming reaction, and hydrogen generated through the reforming reaction is supplied to the fuel electrode 3b of the stack 3 and the other. Oxygen (O ₂ ) is supplied to one of the cathodes 3c, and an oxidation reaction occurs at the anode 3b and a reduction reaction occurs at the cathode 3c. The electrons generated in this process are the anodes 3b. Electricity and heat are generated while moving from the cathode to the cathode 3c, and the electricity is converted into alternating current through the power converter 4 and used to drive various electrical appliances.

In the fuel cell, when the electrolyte membrane 3a of the stack 3 is dried, the conductivity of hydrogen ions (H ⁺ ) is reduced or the electrolyte membrane 3a is contracted so that the contact resistance between the membrane and the electrode is increased. Therefore, when supplying hydrogen to the stack 3, always supply water together.

However, the self-generating system composed of the fuel cell of the conventional structure as described above, even when the electric appliances are reduced and the use of power is reduced, the reformer 2 is operated to generate unnecessary hydrogen, so that the loss of the supplied fuel occurs. There is a problem that the efficiency of the entire system is reduced.

The object of the present invention devised in view of the above point is to reduce the waste of power and waste of fuel supplied to the fuel cell by utilizing a charger for charging and storing electricity generated by the operation of the fuel cell of the self-generating system. The present invention relates to a self-generating system and a control method thereof.

1 is a block diagram showing a self-powered system using a typical fuel cell,

2 is a block diagram showing a self-generating system that is an embodiment of the present invention;

3 is a flowchart illustrating a method of controlling and executing the self-power generation system of FIG. 2;

** Description of the symbols for the main parts of the drawings **

11 fuel tank 12 reformer

12a: reactor 12b: burner

13: stack 13a: electrolyte membrane

13b: fuel electrode 13c: air electrode

14 power converter 14a converter

14b: inverter 16: feed water pump

17: humidifier 18: fuel supply valve of the reformer

19: fuel supply valve of the burner 21: the first charger

22: second charger

The self-generating system for achieving the object of the present invention as described above is to produce hydrogen from the fuel supplied and a reformer equipped with a burner therein, the anode and the cathode are disposed on both sides of the electrolyte membrane between the fuel electrode and the anode Is supplied with a hydrogen or a hydrogen-containing fuel generated in the reformer, while a cathode is provided with a stack for supplying oxygen or an oxygen-containing oxidant to generate electricity and heat by an electrochemical reaction of hydrogen and oxygen. In a self-powered system using a battery, the fuel cell is connected to the stack to charge the electricity generated in the stack, and when the charge is complete, supplying the charged power to the outside, and stops the operation of the fuel cell At least one charger is provided.

In addition, the control method of the self-generating system for achieving the object of the present invention is a standby mode step of stopping the operation of the fuel cell by closing the fuel supply valve of the reformer and the burner formed inside the reformer, and after the standby mode step, the first A voltage judging step of determining whether or not a voltage charged in the charger and the second charger is equal to or greater than each discharge setting voltage, and supplying power to the first charger according to the voltage judging step; According to the voltage determination step, the second step consisting of supplying power to the second charger and at the same time charging the first charger, supplying power to the first charger and at the same time charging the second charger And charging the first charger by operating the fuel cell according to the voltage determining step, and supplying power to the charged first charger. At the same time as the third step consisting of the step of charging the second charger.

Hereinafter, a self-generating power system and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating a self power generation system according to an embodiment of the present invention. As shown in FIG. 2, a self power generation system using a fuel cell includes gasoline or other hydrocarbons (LNG, LPG, CH ₃ OH ... A fuel tank 11 filled with a series of fuel, a reformer 12 connected to the fuel tank 11 to produce hydrogen from a fuel supplied thereto, and a reformer 12 connected to the reformer 12 Oxidation reaction of hydrogen produced from (12) and reduction reaction of oxygen supplied separately occur simultaneously with stack 13 which is generated together with electric superheat, and is connected to the stack 13 and the stack 13 A power converter 14 comprising a converter 14a and an inverter 14b for converting the electricity obtained from the electric power into an alternating current, which is commercial electricity, and is charged by being supplied with power from the converter 14a. Supply power charged in 14b) The first charger 21 and the second charger 22 is provided.

The reformer 12 includes a reactor 12a and a burner 12b therein, a fuel supply valve 18 of a reformer formed in a supply line for supplying fuel to the reactor 12a, and the burner ( And a fuel supply valve 19 of a burner formed in a supply line for supplying fuel to 12b), and the stack 13 contains hydrogen or hydrogen on both sides thereof with an electrolyte membrane 13a interposed therebetween. A fuel electrode (or anode) 13b supplied with a fuel material and an air electrode (or cathode) 13c supplied with an oxidant containing oxygen are disposed.

In the drawings, reference numeral 16 denotes a water supply pump and 17 denotes a humidifier.

Self-powered system using a fuel cell configured as described above has the following operation and action effects.

The fuel supply valve 18 of the reformer and the fuel supply valve 19 of the burner are opened, and the fuel liquid supplied from the fuel tank 11 is mixed with water and air to enter the reformer 12, and the fuel liquid Part of is introduced into the burner 12b of the reformer 12 and burned, and the rest is introduced into the reactor 12a to generate hydrogen through desulfurization, reforming and hydrogen purification. Is supplied to the fuel electrode 13b of the stack 13 to generate electricity and heat while undergoing an electrochemical reaction with oxygen supplied to the air electrode 13c, and the electricity is boosted by the converter 14a. Then, the boosted electricity is converted into a home alternating current by the inverter 14b and applied to each electric product to be used as a power source, or the boosted electricity in the converter 14a is converted into the first charger 21 and 2nd charge When the charging is completed and the charging is completed, electricity charged in the first charger 21 and the second charger 22 is sequentially supplied to the inverter 14b to be used as a power source for each electric product. Will be.

In the fuel cell, when the electrolyte membrane 13a of the stack 13 is dried, the conductivity of hydrogen ions (H ⁺ ) is reduced or the electrolyte membrane 13a is contracted so that the contact resistance between the membrane and the electrode is increased. Therefore, when supplying hydrogen to the stack 13, always supply water together.

3 is a flowchart illustrating a method of controlling and executing the self-generating system configured as described above, and as shown in FIG. 3, the self-generating system includes a fuel supply valve 18 of the reformer and a fuel supply valve of a burner. 19) the standby mode step of stopping the operation of the fuel cell by closing the step, and after the standby mode step, it is determined whether or not the voltage charged in the first charger 21 and the second charger 22 is above the respective discharge set voltage. According to the voltage determination step, and the voltage determination step, the first step consisting of supplying power to the first charger 21, and according to the voltage determination step, the power to the second charger 22 Charging the first charger 21 at the same time of supplying, charging the second charger 22 at the same time as supplying power to the first charger 21, and determining the voltage. Follow the steps, above A third step of operating a battery cell to charge the first charger 21 and to supply power to the charged first charger 21 and to charge the second charger 22 at the same time. Including proceeds.

In addition, after the standby mode step, when the temperature inside the reformer 12 is measured and the temperature inside the reformer 12 is lower than or equal to the set temperature, the burner 12b inside the reformer 12 is operated to maintain the temperature above the set temperature. A heating step is included to proceed.

In the voltage determining step, in the voltage determining step of the first charger 21 determining whether the voltage of the first charger 21 is greater than or equal to the discharge set voltage, and in the voltage determining step of the first charger 21, Determining the voltage of the second charger 22 when the voltage of the first charger 21 is not equal to or greater than the discharge set voltage, and determining whether or not the voltage of the second charger 22 is greater than or equal to the discharge set voltage. Proceed.

The first step is to supply power to the first charger 21. When the voltage of the first charger 21 is equal to or greater than the discharge set voltage in the voltage determining step, the power is supplied to the first charger 21. And determining whether the voltage of the first charger 21 is greater than or equal to the discharge set voltage and determining whether to continuously supply power to the first charger 22.

The second step is to supply power to the second charger 22 and to charge the first charger 21, to supply power to the first charger 21 and at the same time to the second charger 22 As a step of charging, first, power is supplied to the second charger 22 and the first charger 21 is charged as follows.

When the voltage of the first charger 21 is not greater than the discharge set voltage, the voltage of the second charger 22 is greater than the discharge set voltage in the voltage determination step, and the first charger that has completed the first step When the voltage at 22 is not equal to the discharge set voltage, supplying power to the second charger 22, opening the fuel supply valve 18 of the reformer and the fuel supply valve 19 of the burner to open the fuel. Operating the battery; charging the first charger 21; and determining whether or not the voltage of the second charger 22 is equal to or greater than the discharge set voltage. If power is supplied to the terminal 22, and it is not abnormal, it is determined whether the charging voltage charged in the first charger 21 is lower than or equal to the charging set voltage.

When the charging voltage of the first charger 21 is lower than or equal to the charging set voltage, the third step proceeds to supply power through the fuel cell. When the charging voltage is not lower than or equal to the charging set voltage, the fuel of the reformer and the burner And closing the supply valve and stopping charging of the first charger.

In the next step of supplying power to the first charger 21 and simultaneously charging the second charger 22, after stopping the charging of the first charger 21, the first charger 21 is charged to the first charger 21. Supplying power, opening a fuel supply valve 18 of the reformer and a fuel supply valve 19 of the burner to operate a fuel cell, charging the second charger 22, and Determining whether the voltage of the first charger 21 is equal to or greater than the discharge set voltage and determining whether the power supply of the first charger 21 is in progress and if the voltage of the first charger 21 is equal to or greater than the discharge set voltage, When the power is continuously supplied to the first charger 21 and the voltage of the first charger 21 is not equal to or higher than the discharge set voltage, the charging voltage charged in the second charger 22 is equal to or less than the charging set voltage. It is determined whether or not the charging voltage charged in the second charger 22 If the charging set voltage is less than the fuel cell is operated to supply power and at the same time proceeds to the step of charging the second charger 22, and if the charging voltage charged in the second charger 22 is not less than the set charging voltage. Closing the fuel supply valve 18 of the reformer and the fuel supply valve 19 of the burner, stopping charging of the second charger 22, and then returning to the first step of the second step. Proceed.

The third step is to operate the fuel cell to charge the first charger 21 and to supply power to the charged first charger 21 and to charge the second charger 22. First, the step of charging the first charger 21 by operating the fuel cell is as follows.

Operating the fuel cell to charge the first charger 21, and determining whether or not the voltage of the second charger 22 is equal to or higher than a discharge set voltage; If the power is supplied to the power supply, and if it is not abnormal, it is determined whether the charging voltage charged in the first charger 21 is lower than or equal to the charging set voltage.

When the charging voltage of the first charger 21 is lower than or equal to the charging set voltage, the third step proceeds to supply power through the fuel cell. When the charging voltage is not lower than or equal to the charging set voltage, the fuel of the reformer and the burner And closing the supply valve and stopping charging of the first charger.

The next step of charging power to the first charger 21 and simultaneously charging the second charger 22 is to supply power to the first charger 21 in the second step and simultaneously to the second charger. The procedure is the same as in the step 22 of charging.

In addition, after the standby mode step, the temperature inside the reformer 12 is measured to open the fuel supply valve 19 of the burner to supply fuel to the burner 12b when the temperature inside the reformer is less than or equal to a predetermined temperature. By operating the burner 12b using the supplied fuel, the internal temperature of the reformer 12 is maintained above the set temperature.

As described above, the self-power generation system and the control method thereof according to the present invention provide a power source for operating a home appliance by operating a fuel cell.

The fuel cell is operated to supply power to the first charger and the second charger, and when the charging is completed, the electricity of the first charger and the second charger is sequentially supplied, and the fuel is supplied. By stopping the operation of the battery, it is possible to reduce the loss of fuel supplied to the reformer and the stack, thereby increasing the efficiency of the entire self-generation system.

When the fuel cell is stopped, the temperature inside the reformer is detected. When the temperature inside the reformer decreases below the set temperature, the reformer is operated to maintain the set temperature or more, thereby restarting the fuel cell. In operation, it can be quickly activated to generate electricity.

As described above, the self-power generation system and its control method according to the present invention charge some of the electricity generated when the fuel cell is operated to supply power to the charger, and when the charging is completed, supply power to the charger and supply the fuel. By stopping the operation of the battery, there is an effect of reducing the loss of fuel supplied to the reformer and the stack, thereby increasing the efficiency of the entire self-generating system.

In addition, there is an effect of increasing the efficiency of the self-powered system by repeatedly mounting the two or more chargers and at the same time supplying power and charging.

In addition, when the operation of the fuel cell is stopped by the standby mode, the temperature inside the reformer is detected and when the temperature inside the reformer drops below the set temperature, the reformer is operated to maintain the set temperature or more. When the fuel cell is restarted, the fuel cell can be quickly operated to produce electricity so that the fuel can be efficiently used.

Claims (9)

A reformer having a burner mounted therein to generate hydrogen from the supplied fuel, A fuel electrode and an air electrode are disposed on both sides with an electrolyte membrane interposed therebetween, and a fuel electrode containing hydrogen or hydrogen generated from the reformer is supplied to the fuel electrode, while an oxygen or oxygen-containing oxidant is supplied to the cathode. In the self-power generation system using a fuel cell comprising a stack for generating electricity and heat by the electrochemical reaction of The fuel cell includes at least one charger connected to the stack to charge electricity generated in the stack, and supplying charged power to the outside when the charging is completed, and at the same time stopping the operation of the fuel cell. Self-generating system, characterized in that. According to claim 1, wherein the charger is a self-power generation system characterized in that the first charger and the second charger is configured to perform the charging and power supply sequentially. Standby mode step of stopping the operation of the fuel cell by closing the fuel supply valve of the reformer and the burner formed inside the reformer, A voltage judging step of determining whether the voltage charged in the first charger and the second charger is equal to or greater than each discharge set voltage after the standby mode step; According to the voltage determination step, the first step consisting of supplying power to the first charger, According to the voltage determination step, the second step consisting of supplying power to the second charger and at the same time charging the first charger, supplying power to the first charger and at the same time charging the second charger Wow, According to the voltage determination step, the third step consisting of operating the fuel cell to charge the first charger, and supplying power to the charged first charger and at the same time charging the second charger. Control method of a self-powered system, characterized in that proceeding by. The method of claim 3, further comprising a heating step of measuring a temperature inside the reformer after the standby mode to operate a burner inside the reformer to maintain the temperature above the set temperature when the temperature of the reformer is lower than the set temperature. Control method of a self-powered system, characterized in that. The method of claim 3, wherein the determining of the voltage comprises: determining a voltage of the first charger to determine whether the voltage of the first charger is equal to or greater than a discharge set voltage; In the voltage determining step of the first charger, when the voltage of the first charger is not more than the discharge set voltage, determining the voltage of the second charger to determine whether or not the voltage of the second charger is more than the discharge set voltage. Control method of a self-powered system, characterized in that the progress. The method of claim 3, wherein the supplying power to the first charger in the first step comprises supplying power to the first charger when the voltage of the first charger is greater than or equal to a discharge set voltage in the voltage determining step. Wow, And determining whether or not to continuously supply power to the first charger by determining whether the voltage of the first charger is greater than or equal to a discharge set voltage. The method of claim 3, wherein the charging of the first charger at the same time as supplying power to the second charger in the second step Supplying power to the second charger when the voltage of the first charger is not equal to or higher than the discharge set voltage and the voltage of the second charger is equal to or greater than the discharge set voltage; Opening a fuel supply valve of the reformer and burner to operate a fuel cell; Charging the first charger; Determining whether the power supply of the second charger is in progress by determining whether the voltage of the second charger is greater than or equal to a discharge set voltage; When the voltage of the second charger is not equal to or higher than the discharge set voltage, it is determined whether the charging voltage charged in the first charger is lower than or equal to the charging set voltage and whether the first charger is charged or the fuel cell is supplied. Determining whether or not to implement; Closing a fuel supply valve of the reformer and the burner when the voltage of the first charger charged in the first charger is not equal to or lower than the charge set voltage; Self-generation system control method comprising the step of stopping the charging of the first charger. 4. The method of claim 3, wherein the charging of the second charger while simultaneously supplying power to the first charger in the second and third steps comprises: supplying power to the second charger and simultaneously charging the first charger. Supplying power to the first charger after stopping the charging of the first charger in the charging step; Opening a fuel supply valve of the reformer and burner to operate a fuel cell; Charging the second charger; Determining whether the power supply of the first charger is in progress by determining whether the voltage of the first charger is equal to or greater than a discharge set voltage; When the voltage of the first charger is not equal to or higher than the discharge set voltage, it is determined whether the charging voltage charged in the second charger is lower than or equal to the charging set voltage and whether the charging of the second charger is progressed and power is supplied by operating the fuel cell. Determining whether or not to implement; Closing the fuel supply valves of the reformer and the burner when the charging voltage of the second charger is not lower than the charging set voltage; And stopping the charging of the second charger, and then returning to the second step. The method of claim 3, wherein the step of operating the fuel cell of the third step to charge the first charger Operating the fuel cell to charge the first charger; Determining whether the power supply of the second charger is determined by determining whether the voltage of the second charger is greater than or equal to a discharge set voltage; When the voltage of the second charger is not equal to or higher than the discharge set voltage, it is determined whether the charging voltage charged in the first charger is lower than or equal to the charging set voltage, and whether the first charger is charged or the fuel cell is supplied. Determining whether or not to implement; Closing a fuel supply valve of the reformer and the burner when the voltage of the first charger charged in the first charger is not equal to or lower than the charge set voltage; The control method of a self-powered system, characterized in that proceeding including the step of stopping the charging of the first charger.