KR101078964B1 - fuel cell system - Google Patents

Abstract

The present invention provides a power supply of a heat radiating fan for releasing heat energy of a heat recovery line during continuous operation of a fuel cell system so that power generation efficiency can be improved by using electricity produced using heat energy recovered through the heat recovery line. will be.

To this end, the present invention is a fuel supply for supplying fuel, a stack for producing electricity and heat through a chemical reaction of hydrogen, oxygen and carbon dioxide, and the power to convert the direct current generated from the stack into an alternating current to connect to the system A power generation module having a converter; A hot water module having a storage tank in which storage water is stored; A heat exchanger having a heat exchanger receiving heat generated from the stack of the power generation module, a fluid pipe guiding the storage water stored in the storage tank of the hot water module to pass through the heat exchanger, and a circulation pump circulating the storage water in the fluid pipe ; In addition, a low temperature contact point is located on the fluid outlet side passage of the storage tank among the fluid pipes of the heat exchange part, and a high temperature contact point is positioned on the fluid inlet side path of the storage tank of the fluid pipe while the temperature difference between the high temperature contact point and the low temperature contact point. Provided is a fuel cell system comprising: a thermoelectric module having a thermoelectric element for generating electrical energy.

Fuel Cell System, Thermoelectric Module, Heat Exchanger, Directional Valve

Description

Fuel cell system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell system. In particular, a power supply of a radiator for releasing heat energy of a heat recovery line during continuous operation of the system generates electricity using heat energy recovered through the recovery line. By using it, the power generation efficiency can be improved.

In general, a fuel cell system is a cogeneration system that generates electricity and heat through a chemical reaction between hydrogen contained in a hydrocarbon-based material and oxygen or oxygen-containing air.

The fuel cell system generally includes a power generation module and a hot water module.

Here, the power generation module is composed of a stack, a reformer, EBOP (controller, power converter, electrical sensors, etc.), MBOP (fluid machinery, heat exchangers, sensors, etc.), the hot water module is a hot water storage tank, auxiliary boiler And the like.

Along with this, the power generation module and the hot water module are provided with a circulating water pump for circulating the stored water stored in the hot water storage tank, a heat exchanger for heat recovery, and a radiator for cooling the stored water for continuous operation.

The fuel cell system converts city gas supplied to a reformer through a fuel fluid machine into hydrogen and supplies it to the stack, and oxygen is supplied to the stack through an air fluid machine, thereby generating electricity and heat by chemical reaction between hydrogen and coral in the stack. To produce.

At this time, the electricity is supplied to the home through a power converter, the heat is heat-exchanged with the stored water stored in the hot water storage tank to increase the temperature of the stored water.

However, the fuel cell system according to the related art described above stops because the normal operation of the system is impossible because no further temperature rise occurs when the storage water in the hot water storage tank reaches the target temperature.

Accordingly, conventionally, even when the storage water in the hot water storage tank reaches the target temperature, the radiator discharges the entire amount of the thermal energy recovered by driving the radiator to enable the continuous operation of the fuel cell system.

However, additional power is required to drive the radiator, and since the electric power uses a part of electricity generated through the power generation module of the fuel cell system, the cause of lowering the power generation efficiency of the actual fuel cell system is caused. Has the problem.

The present invention has been made to solve the various problems according to the prior art described above, the object of the present invention is to generate additional electricity by using the heat energy recovered during the continuous operation of the fuel cell system, power generation efficiency is It is to provide a new type of fuel cell system that can be further improved.

According to the fuel cell system of the present invention for achieving the above object, a fuel supply (M-BOP) for supplying fuel, a stack for producing electricity and heat through a chemical reaction of hydrogen, oxygen and carbon dioxide, A power generation module having a power converter (E-BOP) for converting the DC electricity generated in the stack into alternating current and linking it to a system; A hot water module having a storage tank in which storage water is stored; A heat exchanger having a heat exchanger receiving heat generated from the stack of the power generation module, a fluid pipe guiding the storage water stored in the storage tank of the hot water module to pass through the heat exchanger, and a circulation pump circulating the storage water in the fluid pipe ; In addition, a low temperature contact point is located on the fluid outlet side passage of the storage tank among the fluid pipes of the heat exchange part, and a high temperature contact point is positioned on the fluid inlet side path of the storage tank of the fluid pipe while the temperature difference between the high temperature contact point and the low temperature contact point. And a thermoelectric module having a thermoelectric element for generating electrical energy.

Here, the heat dissipation fan is configured to further include a heat dissipation fan for cooling the storage water passing through the corresponding pipe line between the portion of the fluid tube of the heat exchange part is located between the low temperature contact of the thermoelectric module and the fluid outlet side of the storage tank, The heat radiating fan is characterized in that configured to receive electricity from the thermoelectric element.

In addition, the fluid pipe constituting the heat exchange unit is a first fluid pipe formed so that the storage water flows back into the storage tank again after passing out the storage water from the storage tank and the heat exchanger, and the fluid outlet side of the storage tank of the first fluid pipe And a second fluid tube branched from a pipeline between the fluid inlet side of the heat exchanger and passing through the low temperature contact point of the thermoelectric element, and then connected to the fluid inlet side pipeline of the heat exchanger, and a heat exchanger among the first fluid tubes. And a third fluid pipe branched from a conduit between the fluid outlet side of the storage tank and the fluid inlet side of the storage tank, and connected to the fluid inlet pipe of the storage tank after passing through the high temperature contact point of the thermoelectric element. Wherein each of the fluid pipe is divided into a direction switching valve for guiding the fluid flow direction is characterized in that each provided.

In addition, the second fluid pipe and the third fluid pipe is characterized in that it is formed as a flat manifold (manifold) tube capable of surface contact with the hot and cold contact.

As described above, the fuel cell system of the present invention has an effect that an inoperable state can be prevented due to excessively high storage water temperature in the storage tank constituting the hot water module even when continuous operation is performed.

In particular, since the power for driving the heat radiating fan operated during continuous operation is provided by a separate thermoelectric module, the consumption of power generated by the fuel cell system can be prevented, thereby achieving higher power generation performance. Have

Hereinafter, a preferred embodiment of the fuel cell system of the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, a fuel cell system according to an exemplary embodiment of the present invention includes a power generation module 100, a hot water module 200, a heat exchange unit 300, and a thermoelectric module 400.

This will be described in more detail below for each configuration.

First, the power generation module 100 is a series of components for producing electricity, including a fuel supply (E-BOP) 110, a stack (120) and a power converter (M-BOP) 130. It is configured by.

Here, the fuel supply unit 110 is a configuration that collectively refers to a mechanical device for supplying fuel to the stack 120, the reformer 111 is included therein.

In this case, the reformer 111 is a series of components for generating hydrogen gas, and not only converts the liquid fuel and water containing hydrogen into hydrogen gas required for electricity generation of the stack 120 by reforming catalytic reaction, It serves to remove harmful substances such as carbon monoxide, which poison fuel cells and shorten their lifespan.

The stack 120 is configured to produce electricity and heat.

In this case, the stack 120 is configured by stacking a fuel cell composed of an electrode, an electrolyte, and a separator, and chemically reacts with oxygen using hydrogen provided from the fuel supply 110 to generate electricity and heat. To produce.

In particular, the stack 120 is provided with a cooling passage 121 for cooling the device, and a circulation pump 122 for the flow of fluid is installed on the cooling passage 121.

In addition, the power converter 130 is a series of configurations that converts the direct current generated by the stack 120 into an alternating current and linked to the grid.

In this case, the power converter 130 includes a power conversion device (PCS; Photovoltaic Power Conditioning System) 131, a controller (not shown), electrical sensors (not shown), and the like.

Next, the hot water module 200 is a series of configurations for generating hot water using the heat energy produced from the power generation module 100 and supplying it to the home, the storage tank 210 in which the stored water is stored. It is configured to include.

Of course, the hot water module 200 may further include a separate auxiliary boiler 220 for heating the storage water in the storage tank 210 using the city gas.

Next, the heat exchange unit 300 heats the heat energy produced from the power generation module 100 with the stored water stored in the storage tank 210 of the hot water module 200 to increase the temperature of the stored water. A series of configurations that play a role.

The heat exchange unit 300 is a heat exchanger 310 for receiving heat generated from the stack 120 of the power generation module 100 and the storage water stored in the storage tank 210 of the hot water module 200 is It includes a fluid pipe (321, 322, 323) for guiding the heat exchanger 310 and a circulation pump (340) for circulating the storage water in the fluid pipe (321, 322, 323).

In this case, the heat exchanger 310 is installed to pass through the cooling passage 121 and the fluid pipes 321, 322, 323 connected to the stack 120, respectively, and serves to heat exchange fluids flowing through the two pipes 121, 321, 322, 323 with each other. Will be performed.

Next, the thermoelectric module 400 is a series of configurations for generating electrical energy by using the temperature difference between the storage water before the heat exchange with the heat exchange unit 300 and the storage water after heat exchange, power generation of the fuel cell system It serves to assist the power generation efficiency by the module 100 can be further improved.

The thermoelectric module 400 is located between the high temperature contact point 411 and the low temperature contact point 412 made of a metal layer and the respective contact points 411 and 412, as shown in FIG. ), A thermoelectric element 410 formed on the outer surface of each of the contacts 411 and 412 and having a heat sink 414 for thermal conduction, and a DC-DC converter 420 for making a stable DC output of the fuel cell. And a DC-AC converter 430 for injecting the produced electricity into the electric field system.

In this case, the low temperature contact point 412 is located on the fluid outlet side of the storage tank 210 of the fluid pipes (321, 322, 323), the high temperature contact 411 is the storage tank of the fluid pipes (321, 322, 323) And located on the fluid inlet side conduit of 210.

That is, the thermoelectric element 410 has a low temperature contact point 412 and the high temperature contact point 411 in contact with the fluid pipe (321,322,323) by the electrical energy due to the temperature difference of the storage water flowing along the fluid pipe (321,322,323) To be created.

On the other hand, among the fluid pipes 321, 322, 323 of the heat exchanger 300 described above, a portion between the portion where the low temperature contact point 412 of the thermoelectric element 410 is located and the fluid outlet side of the storage tank 210 is connected to the corresponding pipe line. A heat dissipation fan 440 is further included to cool the storage water passing through, and the heat dissipation fan 440 is configured to receive electricity from the thermoelectric element 400.

That is, the heat dissipation fan 440 operated to enable continuous operation of the fuel cell system can use the electricity obtained by the thermoelectric element so that the reduction in power generation efficiency by the power generation module 100 can be prevented.

In addition, in the embodiment of the present invention, the above-described fluid pipes 321, 322, 323 may be configured to circulate the storage tank 210 and the heat exchanger 310 by the first fluid pipe 321 and the respective parts of the first fluid pipe 321. The second fluid pipe 322 and the third fluid pipe 323 passing through the low temperature contact 412 and the high temperature contact 411 of the thermoelectric element 410 is branched from. In this case, the second fluid pipe 322 is branched from the pipeline between the fluid outlet side of the storage tank 210 and the fluid inlet side of the heat exchanger 310 of the first fluid pipe 321, the thermoelectric element 410 After passing through the low temperature contact point 412 of the) is configured to be connected to the fluid inlet side of the heat exchanger 310 again, the third fluid pipe 323 is a heat exchanger of the first fluid pipe (321) Branched from the conduit between the fluid outlet side of 310 and the fluid inlet side of the storage tank 210, and after passing through the high temperature contact point 411 of the thermoelectric element 410, the fluid inlet side of the storage tank 210 again It is configured to connect with the pipeline.

In particular, the second fluid pipe 322 and the third fluid pipe is composed of a plate-shaped manifold pipe (pipe) capable of surface contact with the high temperature contact 411 and the low temperature contact 412 It is more preferable that the heat transfer can be made more smoothly, thereby improving the generation efficiency of the electric energy. This is as shown in Figure 3 attached.

In addition, the branched portions of the respective fluid pipes 321, 322, 323 are proposed to further include a direction switching valve 331, 332 for guiding the fluid flow direction.

In this case, the direction switching valve (331,332) is the first to guide the flow of the fluid flowing along the first fluid pipe 321 flows along the second fluid pipe 322 before passing through the heat exchanger (310) A second direction for guiding the flow of the fluid flowing along the first direction switching valve 331 and the first fluid pipe 321 to flow along the third fluid pipe 323 after passing through the heat exchanger 310. The switch valve 332 is configured.

As described above, the structure of each of the fluid pipes 321, 322, and 323 and the structure of each of the directional valves 331, 332 may be operated until the storage water temperature in the storage tank 210 reaches a target temperature, and the storage water temperature is set to a target temperature. After the temperature is reached, the operation can be proceeded differently.

That is, the storage water only flows through the first fluid pipe 321 until the storage water temperature reaches the target temperature, and after the storage water temperature reaches the target temperature, not only the first fluid pipe 321 but also the second The storage water also flows through the fluid pipe 322 and the third fluid pipe 323 to allow the generation of electrical energy by the thermoelectric element 410.

In the following, the operation of the fuel cell system according to the embodiment of the present invention described above will be described in more detail.

First, when the operation of the fuel cell system is made in the initial state, the fuel gas is supplied to the fuel supplier 110 constituting the power generation module 100. In this case, the fuel gas may be a normal city gas.

In addition, the fuel supplier 110 receiving the fuel gas as described above supplies the fuel gas to the reformer 111, and then the fuel gas is converted into hydrogen through the reformer 111 to the stack 120. And oxygen is supplied to the stack 120 through an air fluid machine to produce electricity and heat by chemical reaction of hydrogen and coral in the stack 120.

In this case, the electricity produced through the stack 120 is supplied to the home or other power demand (eg, KEPCO) through the power converter 130.

In addition, heat generated from the stack 120 is heat-exchanged with the fluid circulating in the cooling passage 121 by driving the circulation pump 122, thereby gradually increasing the temperature of the fluid.

In addition, in the above process, as the circulation pump 340 constituting the heat exchange unit 300 is driven, the stored water stored in the storage tank 210 circulates through the first fluid pipe 321.

In the above process, the fluid and the storage water flowing along the cooling passage 121 and the first fluid pipe 321 are exchanged with each other in the process of passing through the heat exchanger 310. That is, the temperature of the fluid flowing along the cooling passage 121 is lowered along with the temperature of the storage water flowing along the first fluid pipe 321.

Therefore, the storage water flowing along the first fluid pipe 321 by the above process is provided into the storage tank 210 to gradually increase the storage water temperature in the storage tank 210.

Meanwhile, when the storage water in the storage tank 210 reaches a target temperature while the above-described series of processes are performed, the first direction switching valve 331 and the second direction switching valve 332 are operated, and the first The flow direction of the storage water flowing along the fluid pipe 321 is allowed to flow along the second fluid pipe 322 and the third fluid pipe 323.

That is, the storage water flowing out of the storage tank 210 flows along the second fluid pipe 322 and then passes through the heat exchanger 310, and the storage water passing through the heat exchanger 310 is the third water. After flowing along the fluid pipe 323 it is to be introduced into the storage tank 210 again.

Accordingly, the relatively high temperature storage water flowing along the third fluid tube 323 is absorbed by the heat sink 414 provided at the high temperature contact point 411 of the thermoelectric element 410, and then the low temperature contact point 412 is opened. Current is generated from the semiconductor layer 413 by the process of being discharged through.

At this time, since the storage water flowing along the third fluid pipe 323 is deprived of heat by the thermoelectric element 410, even though the storage water flows into the storage tank 210, the temperature in the storage tank 210 is maintained. It will not rise.

Thereafter, the current generated from the semiconductor layer 413 is used as a current for driving the heat radiating fan 440, and the surplus current is provided to a home or other power source.

At this time, the heat dissipation fan 440 driven by receiving the current generated from the thermoelectric element 410 serves to further lower the temperature of the storage water flowing through the first fluid tube 321. At the same time to further increase the power generation efficiency by lowering the storage water temperature in the storage tank (210).

When the temperature inside the storage tank 210 drops below the set temperature by the above-described process, the first and the second diverter valves 313 and 314 operate while the storage tank 210 is operated. The storage water therein is allowed to flow only to the first fluid pipe 321 to allow the generation of hot water. Of course, at this time, the operation of the heat radiating fan 440 is stopped.

As a result, as the above-described series of processes are repeatedly performed, continuous operation of the fuel cell becomes possible, and in this process, current required for driving the heat radiating fan 440 is generated by the thermoelectric element 410. The reduction in power generation by the actual fuel cell system does not occur.

1 is a schematic block diagram illustrating a fuel cell system according to a preferred embodiment of the present invention.

2 is a schematic view illustrating a thermoelectric element of a fuel cell system according to an exemplary embodiment of the present invention.

3 is a configuration diagram schematically showing the installation structure of the second fluid pipe and the third fluid pipe of the fuel cell system according to the preferred embodiment of the present invention.

Explanation of symbols for main parts of the drawings

100. Power Generation Module 110. Fuel Supply

111. Reformer 120. Stack

121. Cooling passage 122. Circulation pump

130. Power Converter 131. Power Converter

200. Hot water module 210. Storage tank

220. Auxiliary boiler 300. Heat exchanger

310. Heat exchangers 321,322,323. Fluid tube

331,332. Directional valves 340. Circulation pump

400. Thermoelectric module 410. Thermoelectric element

411,412. On-contact 413. Semiconductor layer

414. Heat sink 420 .DC-DC converter

430. DC-AC converter 440. Heat dissipation fan

Claims (4)

Fuel supply (M-BOP) for supplying fuel, Stack for producing electricity and heat through chemical reaction of hydrogen, oxygen and carbon dioxide, and DC electricity generated from the stack is converted into AC and connected to the system A power generation module having a power converter (E-BOP); A hot water module having a storage tank in which storage water is stored; A heat exchanger having a heat exchanger receiving heat generated from the stack of the power generation module, a fluid pipe guiding the storage water stored in the storage tank of the hot water module to pass through the heat exchanger, and a circulation pump circulating the storage water in the fluid pipe ; And, The low temperature contact point is located on the fluid outlet side of the storage tank of the fluid pipe of the heat exchanger, and the high temperature contact point is located on the fluid inlet side of the storage tank of the fluid pipe, and the electrical energy is reduced by the temperature difference between the high temperature contact point and the low temperature contact point. A thermoelectric module having a thermoelectric element for generating a fuel cell system, characterized in that it comprises a. The method of claim 1, A heat dissipation fan for cooling the storage water passing through the corresponding pipe line is further configured at a portion between the fluid pipe of the heat exchange part where the low temperature contact point of the thermoelectric module is located and the fluid outlet side of the storage tank. The heat dissipation fan is configured to receive electricity from the thermoelectric element. The method of claim 1, The fluid pipe forming the heat exchange part A first fluid pipe configured to allow the storage water to flow into the storage tank again after passing the storage water from the storage tank and passing through a heat exchanger; A second branch which is branched from a conduit between the fluid outlet side of the storage tank and the fluid inlet side of the heat exchanger of the first fluid pipe and passes through the low temperature contact point of the thermoelectric element and is connected to the fluid inlet side conduit of the heat exchanger again Fluid pipe, A third branched from the conduit between the fluid outlet side of the heat exchanger and the fluid inlet side of the storage tank and passing through the high temperature contact point of the thermoelectric element and then connected to the fluid inlet side conduit of the storage tank again; Configured to include a fluid tube, Fuel cell system, characterized in that each of the diverging portion between the fluid pipe is provided with a direction switching valve for guiding the fluid flow direction. The method of claim 3, wherein The second fluid pipe and the third fluid pipe is a fuel cell system, characterized in that formed in the flat manifold (manifold) tube capable of surface contact with the hot and cold contact.

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