KR20110130377A - Apparatus for load following fuel cell power generation system in a ship and method thereof - Google Patents

Abstract

PURPOSE: A load following apparatus for power generation system of fuel cell is provided to offer the necessary power by power generation system using hydrogen, and load follow by using polymer electrolyte membrane fuel cell. CONSTITUTION: A load follower apparatus for power generation system of fuel cell comprises: external reformer extracting hydrogen by reforming LNG transmitted from the LNG tank(100), and transferring the extracted hydrogen to the hydrogen tank; a hydrogen control part controlling the amount of flowing to a molten carbonate fuel cell(MCFC)(102) and polymer electrolyte membrane fuel cell(PEMFC)(112); a power control part supplying the generated power of PEMFC to the place in which power is necessary, and controlling power generation capacity as planned by controlling the generation capacity of MCFC stack by stack.

Description

Load tracking device for fuel cell power generation system and its method {Apparatus for load following fuel cell power generation system in a ship and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shipboard fuel cell, and in particular, a load tracking device for a fuel cell power generation system suitable for mounting on a ship by adding a load tracking function to a molten carbonate fuel cell (hereinafter referred to as MCFC). It is about a method.

In general, a fuel cell refers to a cell that directly converts chemical energy generated by oxidation into electrical energy. Unlike chemical cells, fuel cells are continuously supplied with reactants from outside and reaction products are removed out of the system. The most typical type of fuel cell is a hydrogen-oxygen fuel cell, and the fuel cell is divided into a high temperature type and a low temperature type (eg, a high temperature type at 300 ° C or higher, and a low temperature type) according to the operating temperature.

Specifically, hydrogen passes through the anode and oxygen passes through the cathode. Hydrogen reacts with oxygen electrochemically to generate water, generating current at the electrode. As electrons pass through the electrolyte, direct current power is generated and heat is incidentally produced. DC current is used as the power of a DC motor or converted into alternating current by an inverter. The heat generated from the fuel cell can be used to generate steam for reforming or to be used for heating and cooling. If not used, it is discharged as exhaust heat.

In order to improve the power generation efficiency, the second generation of high-temperature MCFC which does not use a noble metal catalyst, and a polymer electrolyte membrane fuel cell (PEMFC) which generates power with higher efficiency, It is called the third generation fuel cell.

In particular, since the MCFC is capable of large-capacity output and has a longer lifespan than other fuel cells, various studies have been made for use as a fuel cell for ships.

Korean Laid-Open Patent No. 2002-0031686 (published May 5, 2002)

In the conventional MCFC operating as described above, since there is no load tracking capability, it is difficult to mount it for ship use. In other words, the MCFC produces power at full loading once the stack is at its end of life.

This can be a problem for ships with large differences in power consumption during voyage and at sea port. In order to solve this problem, ships with large variations in power consumption may be equipped with additional batteries, but in this case, too much expensive batteries are required, which increases costs and increases weight and volume.

In addition, even when the surplus power produced in the MCFC is stored as a battery, the MCFC has a problem that it is not easy to find a use to use the power stored in the battery because the power is continuously produced in full loading.

Accordingly, the present invention provides a load tracking device for a fuel cell power generation system and a method thereof that can be mounted on a ship by adding a load tracking function to a molten carbonate fuel cell (MCFC).

In addition, the present invention is equipped with a water-receiving system and a PEMFC in the MCFC mounted on a vehicle such as a ship or a vehicle, it is possible to supply additional power required by the load tracking through the PEMFC to the MCFC during ship operation A load tracking device for a fuel cell power generation system and a method thereof are provided.

In addition, the present invention, by installing an electrolytic system and a PEMFC in addition to the MCFC mounted on the vessel, to produce electric power to the MCFC during the operation of the vessel, and accumulate hydrogen produced by driving the hydroelectric system with surplus power generated at this time In addition, when additional power is required in addition to MCFC during navigation, it provides a load tracking device and method for fuel cell power generation system that can supply the necessary power through the load tracking through PEMFC and the production of power using hydrogen.

A load tracking device for a fuel cell power generation system according to an embodiment of the present invention includes a molten carbonate fuel cell (MCFC) that generates power by receiving hydrogen generated by extraction from an LNG tank, and receives surplus power of MCFC to supply water. Compares the power capacity of MCFC with the load power capacity and the MCFC power generation system, which can generate hydrogen by electrolysis, and the polymer electrolyte membrane fuel cell (PEMFC) that can receive the hydrogen from the hydrolysis system and produce the required additional power. And determining whether additional power is needed, and controlling the PEMFC to operate when additional power is required.

In one embodiment, a load tracking method for a fuel cell power generation system includes: extracting and generating hydrogen from an LNG tank; generating power from hydrogen extracted from a molten carbonate fuel cell (MCFC); The process of generating hydrogen by electrolysis of water by receiving surplus power of MCFC and comparing the load power capacity with the generation capacity of MCFC through the control unit controlling hydrogen generation and power generation to determine whether additional power is needed. The process and, if it is determined that the additional power is required, the process includes the process of producing additional power by receiving hydrogen from the electrolysis system under the control of the control unit in the polymer electrolyte membrane fuel cell (PEMFC).

In one embodiment of the present invention, a load tracking method for a fuel cell power generation system is performed by comparing a power generation capacity of a molten carbonate fuel cell (MCFC) installed in a ship to generate power from hydrogen extracted from LNG and a load power capacity of the ship. If additional power is needed through the process of following the load and following the load, the polymer electrolyte membrane fuel cell (PEMFC) that receives hydrogen from the electrolytic system that produces hydrogen through electrolysis of water by surplus power of MCFC Generating the necessary additional power.

Another embodiment of the present invention is a load tracking device for a fuel cell power generation system, which is installed in a ship and compares the power generation capacity of a molten carbonate fuel cell (MCFC) that generates electric power from hydrogen extracted from LNG with a load power capacity of the ship. In the following process, and if additional power is required through the following of the load, the polymer electrolyte membrane fuel cell (PEMFC) receiving hydrogen from the electrolytic system for producing hydrogen through the electrolysis of water to the surplus power of the MCFC Control to generate the necessary additional power.

According to another embodiment of the present invention, a load tracking method for a fuel cell power generation system includes an external reformer for reforming LNG received from an LNG tank to extract hydrogen, and transferring the extracted hydrogen to a hydrogen tank, and controlling the hydrogen supply of the hydrogen tank. The hydrogen control unit for controlling the hydrogen supply amount flowing into the molten carbonate fuel cell (MCFC), the polymer electrolyte membrane fuel cell (PEMFC) through the power supply, and the power generation capacity of the PEMFC first supplying the power where necessary, the power generation capacity of the MCFC It includes a power control unit for controlling the power generation capacity to control the power generation by a predetermined ratio by stack.

According to the load tracking device and method for fuel cell power generation system according to an embodiment of the present invention as described above has one or more of the following effects.

According to the load tracking device for fuel cell power generation system and the method according to an embodiment of the present invention, after producing and accumulating hydrogen with surplus power of MCFC during ship operation, if additional power is needed, it is easily added using hydrogen in PEMFC. Since the power can be supplied, a large-capacity long life MCFC can be mounted on a ship, and the MCFC has the effect of enabling high efficiency driving on a ship.

1 is a block diagram showing the structure of a fuel cell power generation system including a load tracking device mounted on a ship according to an embodiment of the present invention;
2 is a flowchart illustrating a power generation procedure of a fuel cell power generation system according to an embodiment of the present invention;
3 is a flowchart illustrating a load tracking procedure of a fuel cell power generation system according to an exemplary embodiment of the present invention.
4 is a block diagram illustrating a structure of a fuel cell power generation system including a load tracking device mounted on a ship according to another embodiment of the present invention;
5 is a flowchart illustrating a power generation and load tracking procedure of a fuel cell power generation system according to another exemplary embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The present invention is to add a load tracking function to a long-life molten carbonate fuel cell (MCFC) capable of large-capacity output and to be mounted on a vehicle or a vehicle, such as a ship electrolytic system and a PEMFC In addition, the ship produces electric power through the MCFC when the ship is operating, and the hydrogen generated by driving the hydration system with the surplus power generated at this time, and accumulates hydrogen, and if additional power is required in addition to the MCFC during the voyage, the load through the PEMFC It is to supply the necessary power through tracking and power generation using hydrogen.

On the other hand, MCFC and PEMFC described in detail in the following examples may each be one or more fuel cells, a fuel converter for delivering air and fuel to the fuel cell, as well as a fuel cell, a heat exchanger using the heat released, It may be a fuel cell system including an inverter for converting after storing the electric power in a storage battery, a controller for controlling each device, and the like.

1 is a block diagram showing the structure of a fuel cell power generation system including a load tracking device mounted on a ship according to an embodiment of the present invention.

Referring to FIG. 1, a fuel cell power generation system includes an LNG tank 100, an MCFC 102, a battery 104, a motor 106, an electrolytic system 108, a hydrogen tank 110, a PEMFC 112, Control unit 114 and the like.

The LNG tank 100 extracts hydrogen using LNG as a raw material, and the extracted hydrogen flows into the MCFC 100. In this case, the MCFC 100 generates electric power by using the introduced hydrogen and oxygen in the air. Thereafter, power generated through the MCFC 100 is transferred to the motor 106 to drive the motor 106, and some power is transferred to the battery 104 to charge the power. However, since the fuel cell power generation system including the MCFC 102, the battery 104, and the motor 106 has no load tracking, energy efficiency may be reduced, and as a solution to this, additional power may be used by using the battery 104. In case of supplying, since many batteries 104 must be mounted, there are also problems that may occur due to the cost and the weight and volume of the many batteries 104. And a hydrogen tank 110, a PEMFC 112, a controller 114, and the like.

At this time, the maximum production power of the MCFC 102 is set to the average power production amount of the ship to be mounted in the ship. The electrolytic system 108 generates hydrogen and oxygen by electrolyzing water (H 2 O) generated during power generation of the MCFC 102 with surplus power generated from the power generated from the MCFC 102, and producing hydrogen and oxygen. To accumulate. At this time, the produced hydrogen is compressed and stored in the hydrogen tank 110, the hydrogen stored in the hydrogen tank 110 is later supplied to the PEMFC 112 to generate power through the PEMFC (112). The PEMFC 112 is suitable for use as a backup power source because of its low temperature maneuverability and high reactivity.

The control unit 114 controls the respective components, and in particular, the process control for maintaining the pressure and temperature as well as the flow rate control of fuel or air to smoothly perform power generation of the MCFC 102 and the PEMFC 112. Perform.

In addition, the surplus power generated through the MCFC 102 is stored in the battery based on the load tracking unit 116 in the controller 114 to track whether the current power required in the ship and the power produced through the MCFC 102 are loaded. In order to control the power supply to the electro-hydraulic system, or if the production power of the MCFC 102 is insufficient, the PEMFC 112 may control additional power production.

For example, if the power capacity required for the entire ship is 100%, the MCFC 102 sets about 70% as the maximum capacity and mounts it on the ship. Due to the nature of the ship's operation, the full power 100% loading state only accounts for a portion of the voyage. Most loads are 70-80% and power consumption is significantly lower near port of call.

Even when arriving at the port of call or when the power consumption is low, the MCFC 102 constantly generates 70% of the power, so that the surplus power generated at this time is supplied to the receiving system 108, and the receiving system 108 The water generated from the MCFC 102 is electrolyzed to produce hydrogen. The hydrogen produced in this way is stored and supplied directly from the hydrogen, using the PEMFC 112 to supply an additional 30% of the power that is insufficient for the MCFC 102 to produce a 100% power load. Done.

2 is a flowchart illustrating a power generation procedure of a fuel cell power generation system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the MCFC 102 in the fuel cell power generation system mounted on the ship in step 200 generates power using hydrogen supplied from the LNG tank 100, and the generated power requires power in the ship. Delivered (eg, motor 106). However, since the MCFC 102 produces a constant power without increasing or decreasing the power production according to the required power, if surplus power is generated in addition to the current power required in the ship at step 202, the MCFC 102 proceeds to step 204 and surplus power of the preset capacity. To be stored in the battery 104.

If surplus power is generated in addition to the surplus power stored in the battery 104 in operation 206, the surplus power generated is supplied to the electrolysis system 108 to transmit the surplus power to the MCFC 102 in operation 208. Hydrogen is produced by electrolysis on the water discharged from), and the produced hydrogen is compressed and stored in the hydrogen tank 110.

Thereafter, in step 210, the stored hydrogen is supplied to the PEMFC 112 later under the control of the controller 114 to allow generation of additional power in the PEMFC 112.

As such, the surplus power is stored in the battery 104 firstly because it is disadvantageous in terms of energy efficiency to produce hydrogen using the electrolysis system 108 and then produce electricity using the PEMFC 112. The power of the set capacity or% is stored directly in the battery 104, and when additional power is needed later, the power stored in the battery 104 is implemented first.

3 is a flowchart illustrating a load tracking procedure of a fuel cell power generation system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the load follower 116 of the controller 114 periodically checks the load power capacity, that is, the required power value in the ship, and performs comparison with the capacity currently generated through the MCFC 102. If the load power capacity is greater than the power generation capacity, the process proceeds to step 304 to compensate for the insufficient power generation capacity through the additional power production of the PEMFC 112, and then proceeds to step 306.

However, if the load power capacity is less than or equal to the power generation capacity in step 302, the process proceeds to step 306 to determine whether the load power capacity and the power generation capacity are the same, and in this case, proceeds to step 308 to maintain the current operation state. Done. However, in step 306, when the load power capacity and the power generation capacity are not the same, that is, when the load power capacity is smaller than the power generation capacity, surplus power may occur. In step 310, surplus power generated through the MCFC 102 is received. Transfer to system 108 to generate hydrogen.

As such, since the PEMFC 112 has good load followability, the PEMFC 112 can be easily operated whenever needed to produce power, so that additional power can be supplied quickly if there is only hydrogen stored therein.

4 is a block diagram illustrating a structure of a fuel cell power generation system including a load tracking device mounted on a ship according to another embodiment of the present invention.

Referring to FIG. 4, the fuel cell power generation system includes an LNG tank 400, an external reformer 402, a hydrogen tank 404, an MCFC 406, an electrolytic system 408, a PEMFC 410, and a hydrogen controller 412. ), A power control unit 414, a motor, a battery 418, and the like.

LNG is delivered from the LNG tank 400 in which LNG is stored, and hydrogen is obtained through reforming in the external reformer 402, and the obtained hydrogen is stored in the hydrogen tank 404.

Hydrogen stored in the hydrogen tank 404 delivers hydrogen to the MCFC 406 and the PEMFC 410 through flow control of the hydrogen control unit 412 connected to the hydrogen tank 404. In this case, the MCFC 406 generates power by using the introduced hydrogen and oxygen in the air. At this time, the predetermined amount of power is transmitted to the system 408 by receiving a predetermined amount of power generated through the MCFC 406. Normally, surplus power remaining after driving the motor 416 and storing the battery 418 is transmitted to the system 408.

Accordingly, the electrolytic system 408 electrolyzes the transferred power and water (H 2 O) generated during the power generation of the MCFC 406 to produce hydrogen and oxygen, and to store the produced hydrogen in the hydrogen tank 404 again. do.

In the PEMFC 410, power is generated by hydrogen introduced from the hydrogen tank 404 under the control of the hydrogen controller 412, and the motor 416 is driven by the generated power.

The power controller 414 controls the power generated by being connected to the MCFC 406 and the PEMFC 410, and requests the hydrogen inflow control according to the power information and the required power generated through the hydrogen controller 412. The motor 416 is driven by the power generated through the MCFC 406 and the PEMFC 410.

For example, if the power capacity required for the entire ship is 100%, the power control unit 414 sets the power generation rate at 70% of the MCFC 406 and 30% of the PEMFC 410, and the power when the ship starts to operate. Supply 30% to the PEMFC 410 which has good load followability, and gradually increase the power supply ratio of the MCFC 406 so that when the ship leaves the port and becomes a steady state of long-term operation 70% of the phosphorus may be controlled to be supplied by the MCFC 406.

As such, the power control unit 414 first supplies the power generation capacity of the PEMFC 410 to the place where power is needed, and gradually increases the power generation capacity of the MCFC 406 at a predetermined ratio, so that the MCFC 406 is fully loaded. While rising until then, the PEMFC 410 may control the power generation capacity to be stepped down in inverse proportion to the MCFC 406.

In addition, the MCFC 406 composed of each stack is controlled so that the supply of power is divided by 10%, MCFC 406 40%, PEMFC 410 30% when additional power is required in the state, MCFC By controlling 406 by 10% and performing power generation, MCFC may only use 30% of additional power if the ship continues to drive at 70% in the long run.

That is, when the entire capacity of the MCFC 406 is mounted as a single control system, it may be very inefficient to start and stop a large amount of power at once, so that the control is divided by the stack by 10% of the total power and the like. . Such power control is economical because it can reduce the use rate of the expensive and short-lived battery 418.

The battery 418 serves as a buffer for receiving and storing power from the MCFC 406 and may be powered from the PEMFC 410 in an implementation manner.

The motor 416 is a driving device for driving a ship by receiving power, and may refer to all devices that require power in the ship.

5 is a flowchart illustrating a power generation and load tracking procedure of a fuel cell power generation system according to another exemplary embodiment of the present invention.

Referring to FIG. 5, in step 500, the external reformer 402 receives hydrogen from the LNG tank 400 to reform hydrogen to generate hydrogen, and the generated hydrogen is stored in the hydrogen tank 404.

In step 502, the hydrogen stored in the hydrogen tank 404 is transferred to the MCFC 406 and the PEMFC 410 through the hydrogen control unit 412, and the MCFC 406 and the PEMFC 410 transfer power through the delivered hydrogen. The power generation is to control the power generation rate for the MCFC 406 and PEMFC 410 through the power control unit 414.

MCFC 406 and PEMFC 410 are MCFC 406 if the power capacity required for the entire ship is 100% to compensate for the shortcomings of MCFC 406 performing full loading when the ship is on board. ) Sets about 70% at maximum capacity, and PEMFC 410 sets about 30% at maximum capacity and mounts it on a ship.

When the vessel starts to operate in step 504, in step 506, the power control unit 414 supplies power to the PEMFC 410 having good load followability, and in step 508, increases the power generation rate of the MCFC 406 step by step. Supply sequentially.

That is, the power supply in each stack of the MCFC 406 is controlled to be generated by dividing by 10%, for example. The power control unit 414 controls the power generation rate for each stack, or controls the power supply rate by controlling the hydrogen supply amount through interworking with the hydrogen control unit 412.

In operation 510, the ship enters a fixed state of long-term operation. If the required operating power is fixed at, for example, 70% of the total production power, in step 512, the power control unit 414 of the MCFC 406 is configured. In step 514, if power control is performed in step 514, the MCFC 406 generates power in steps of 10% and operates 40% first, and the remaining 30% of power is produced by the PEMFC (410). ) So that it can be supplied through

Then, when more than 70% of the power is required for ship operation, additional power is produced and supplied to the ship through power control of the MCFC 406.

Meanwhile, the MCFC 406 may provide surplus power generated through full loading or step-by-step power generation to the electrolysis system 408 and the battery 418 at a predetermined ratio.

However, when the power control unit 414 controls to fully load the MCFC 406 in step 512, 70% power required for long-term operation is supplied through the MCFC 406 in step 516. Control to be supplied through the PEMFC (410).

Meanwhile, in the embodiment of the present invention, the ratio of the MCFC to the total power consumption is set to 70% or the power is produced in steps of 10%, but the power output ratio is described in the embodiment of the present invention. It can be changed according to the implementation method, and the power production rate of the PEMFC can also be changed according to the capacity change of the MCFC.

As described above, the load tracking device and method for fuel cell power generation system according to the embodiment of the present invention, to add a load tracking function to a long-life molten carbonate fuel cell (MCFC) capable of large-capacity output to be mounted on a ship For the purpose, the MCFC mounted on the ship is equipped with an electrolytic system and an additional PEMFC to produce electric power by the MCFC during the operation of the vessel, and the hydrogen generated by driving the hydroelectric system with the surplus power generated at this time is accumulated. In addition, if additional power is needed in addition to MCFC during voyage, it is supplied by load tracking through PEMFC and power generation using hydrogen.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

100: LNG tank 102: MCFC
104: battery 106: motor
108: hydroelectric system 110: hydrogen tank
112: PEMFC 114: control unit
116: load follower
400: LNG tank 402: external reformer
404: hydrogen tank 406: MCFC
408: hydroelectric system 410: PEMFC
412: hydrogen control unit 414: power control unit
416: motor 418: battery

Claims (5)

An external reformer for reforming the LNG received from the LNG tank to extract hydrogen, and transferring the extracted hydrogen to the hydrogen tank;
A hydrogen control unit controlling hydrogen supply amount flowing into a molten carbonate fuel cell (MCFC) and a polymer electrolyte membrane fuel cell (PEMFC) through hydrogen supply control of the hydrogen tank;
A power control unit that supplies power generation capacity of the PEMFC to a place where power is needed first, and controls power generation capacity to generate power at a predetermined rate by controlling the generation capacity of the MCFC for each stack;
Load tracking device for a fuel cell power generation system comprising a.
The method of claim 1,
The power control unit,
Power control is performed in conjunction with the hydrogen control unit, and the power generation capacity of the PEMFC is first supplied to a place where power is needed, and the power generation capacity of the MCFC is gradually increased at a predetermined rate, until the MCFC is fully loaded. In the meantime, the PEMFC stepping down the generation capacity in inverse proportion to the MCFC load tracking device for a fuel cell power generation system.
The method of claim 1,
The load tracking device,
Receiving a surplus power of the MCFC to electrolyze water to generate hydrogen, and to deliver the generated hydrogen to the hydrogen tank;
A battery for storing surplus power of the MCFC,
The surplus power distribution of the MCFC is carried out under the control of the power control unit load tracking device for a fuel cell power generation system, characterized in that.
A process of extracting hydrogen by reforming LNG received from an LNG tank in an external reformer and transferring the extracted hydrogen to a hydrogen tank;
Controlling a hydrogen supply amount flowing into a molten carbonate fuel cell (MCFC) and a polymer electrolyte membrane fuel cell (PEMFC) through a hydrogen supply control of the hydrogen tank in a hydrogen control unit;
A process of controlling a generation capacity of the PEMFC by supplying power generation capacity of the PEMFC to a place where power is needed first and controlling the generation capacity of the MCFC for each stack to generate a predetermined rate
Load tracking method for a fuel cell power generation system comprising a.
The method of claim 4, wherein
The process of controlling the power generation capacity,
The power control unit performs power control in conjunction with the hydrogen control unit, and first supplies power generation capacity of the PEMFC to a place where power is needed, and raises the generation capacity of the MCFC step by step at a predetermined rate, so that the MCFC is fully loaded. While increasing until the PEMFC, the load tracking method for a fuel cell power generation system, characterized in that to lower the generation capacity in inverse proportion to the MCFC.

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