KR101205538B1 - A solid oxide fuel cell system - Google Patents

Abstract

PURPOSE: A solid oxide fuel cell system which promotes stable drive and efficiency and facilitates control of flow rate and temperature of an inner system is provided to facilitate temperature control on the inner system and to obtain stability during driving. CONSTITUTION: A solid oxide fuel cell system(100) comprises a high temperature box(110) and an air pre-heater exit valve(160). The high temperature box comprises a fuel cell stack(111) and a fuel reformer(112a), first and second catalytic combustors(116a,116b), a vaporizer(114) connected to the first catalytic combustor, a air pre-heater(115) connected to the second catalytic combustor, a first heat exchanger(118a) connected to the vaporizer, a second heat exchanger (118b) connected to the fuel cell stack, and a third heat exchanger(118c) connected to the air pre-heater. [Reference numerals] (110) High temperature box; (111) Stack; (112a) Fuel reformer; (113) Fuel reformer pre-heater; (114) Vaporizer; (115) Air pre-heater; (116a) The first catalytic combustor; (116b) The second catalytic combustor; (117) Fuel reformer pre-heater; (118a) The first heat exchanger; (118b) The second heat exchanger; (118c) The third heat exchanger; (120) The fourth heat exchanger; (130) Purifier; (140) Vaporizer exit valve; (150) Stack non-reactive vapor liquid exit valve; (160) Air pre-heater exit valve; (171) The first vapor liquid isolator; (172) The second vapor liquid isolator; (180) Hot water storage tank; (AA) Air; (BB) Exhausted gas; (CC) Exhausted gas

Description

Solid oxide fuel cell system {A SOLID OXIDE FUEL CELL SYSTEM}

The present invention relates to a solid oxide fuel cell system, and more particularly, to a solid oxide fuel cell system that facilitates flow rate and temperature control inside the system.

A fuel cell is an energy conversion device that directly converts chemical energy of a fuel into electrical energy through an electrochemical oxidation reaction of the fuel, and continuous power generation is possible by supply of fuel.

Compared with the existing power generation unit, theoretically high generation efficiency can be obtained, and it is a renewable energy generation system that does not emit pollutants other than water when using hydrogen as a fuel.

These fuel cells vary in characteristics depending on the type of electrolyte. The solid oxide fuel cell is composed of a ceramic and an electrolyte, and is operated at a high temperature of 600 to 1000 ° C., and various fuels such as hydrogen, carbon monoxide, and methane can be used.

In addition, fuel cells are easy to combine heat generation and combined cycle power generation, and research is being conducted into domestic, distributed power generation systems and large power generation systems.

When manufacturing such a fuel cell system, it is necessary to construct a stack in which a plurality of cells are stacked using a separator and a sealing material in accordance with the power generation capacity. The system must be designed accordingly.

On the other hand, the solid oxide fuel cell operates at a high temperature (600 to 1000 ° C.) and consists of a high temperature part such as a fuel reformer, a vaporizer, a combustor, a heat exchanger, a reactant supply device, a system control and monitoring device, a power converter, and the like around a stack. Can be.

Of these stacks operating at high temperatures, the operating temperature is very important. If the operating temperature is lower than the appropriate temperature, the performance of the cell is sharply lowered, and if the operating temperature is high, a problem arises in that the metal separator is oxidized and the sealing material is deteriorated.

In addition, a fuel reformer that converts a hydrocarbon fuel into a gas containing a large amount of hydrogen by a catalytic reaction can also be operated normally only when it is controlled within an appropriate temperature range.

Temperatures in key areas such as catalytic combustors for burning unreacted stack fuel, vaporizers for supplying steam for fuel reformers, and reactant preheaters must also be controlled to a constant temperature to prevent material corrosion and perform necessary functions.

In general, the fuel cell stack is supplied with an excess amount of fuel in consideration of the fuel utilization rate, and an amount of heat is supplied where necessary by burning fuel that does not react to electricity production.

The temperature control and thermal management of the solid oxide fuel cell system is performed by supplying the heat generated by burning the reaction heat and the unreacted gas from the stack to a necessary place inside the system through a heat exchanger. As such, it is very important to control the system main site temperature.

For this reason, the optimal heat exchange network is constructed in consideration of the flow rate, calories of the reactants, and the operating temperature of the main parts when designing the system. There was a problem going down.

This problem is effective in controlling the internal temperature by adjusting the flow of reactants and feeds by installing a valve inside the solid oxide fuel cell system.However, due to the high temperature operation of over 700 ℃, sealing and valve operation There is a lot of difficulties, and there is a problem that costs a lot to produce a high temperature characteristics.

In addition, changing the reactant flow rate affects all parts of the vaporizer, the reformer, the stack, and the like, and controlling only the temperature of a specific part is also a difficult problem.

Accordingly, there is a need for a method for stable operation and efficiency improvement of a solid oxide fuel cell system operated at high temperature.

In order to solve the above-mentioned conventional problems, the present invention provides a solid oxide fuel cell which can change the opening angle of the valve by branching the internal pipe of the solid oxide fuel cell system into several parts and installing a valve on the branched pipe outlet side. Provide a system.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood from the following description.

In order to achieve the above object, the solid oxide fuel cell system according to an aspect of the present invention, in the internal space, the fuel cell stack and the fuel reformer, the first and second catalytic combustor connected to the fuel reformer, the first catalytic combustor A connected vaporizer, an air preheater connected to the second catalytic combustor, a first heat exchanger connected to the vaporizer, a second heat exchanger connected to the fuel cell stack, a third heat exchanger connected to the air preheater, And a hot box having an airtight function and a vaporizer outlet valve located outside of the hot box and connected to the first heat exchanger, a stack unreacted fuel outlet valve connected to the second heat exchanger, and the third row. An air preheater outlet valve connected to the exchanger, wherein unstacked fuel and internal air of the hot box are phased through the heat exchanger. The amount of heat required is supplied to the inside of the hot box, and the vaporizer outlet valve, the stack unreacted fuel outlet valve, and the air preheater outlet valve adjust the differential pressure of each pipe according to the opening angle of each valve to distribute the stack unreacted fuel. And control the internal temperature of the hot box.

In one aspect of the invention, the fuel cell stack and the fuel reformer is located at the top of the inner space of the hot box, the first and second catalytic combustor is located at the bottom of the fuel cell stack and the fuel reformer, the vaporizer and An air preheater is located in parallel at the bottom of the first and second catalytic combustors, and the first, second and third heat exchangers are located at the bottom of the first and second catalytic combustors in consideration of convection and operating temperatures inside the hot box. Are placed in parallel.

In one aspect of the invention, the hot box further comprises a third catalytic combustor and an auxiliary fuel reformer, wherein the third catalytic combustor combusts a portion of the stack unreacted fuel and the auxiliary fuel reformer is the stack unreacted fuel. Partial combustion of the fuel activates a reforming reaction to control the temperature of the fuel cell stack and fuel reformer.

In one aspect of the invention, an igniter located outside the hot box and combusting the stack unreacted fuel discharged to the outside through the stack unreacted fuel outlet valve and a fourth heat exchanger for producing hot water due to combustion of the igniter. The hot water production of the fourth heat exchanger further includes lowering the temperature of the exhaust gas discharged through the vaporizer outlet valve, the stack unreacted fuel outlet valve and the air preheater outlet valve.

In one aspect of the invention, where the first, second and third heat exchangers produce hot water, the hot water production of the first, second and third heat exchangers may comprise the vaporizer outlet valve, the stack unreacted fuel outlet valve and the air preheater. Lower the temperature of the exhaust gas discharged through the outlet valve.

In one aspect of the invention, the cathode exhaust gas of the fuel cell stack stays inside the hot box and is combusted with the stack unreacted fuel in the first and second catalytic combustors to provide a high temperature exhaust gas.

In one aspect of the invention, the stack unreacted fuel outlet valve controls the temperature when the temperature of the pipe connected to the fuel cell stack, air preheater and vaporizer is overheated.

In one aspect of the invention, when the valve of the stack unreacted fuel outlet is opened, the differential pressure of the pipe connected to the stack unreacted fuel outlet valve is reduced so that a portion of the stack unreacted fuel is removed from the first and second catalytic combustors. By discharging to the outside without passing, the amount of fuel burnt in the inside of the hot box is reduced to control the internal temperature of the hot box.

In one aspect of the present invention, the third catalytic combustor and the auxiliary fuel reformer is an integral structure of a double pipe, an auxiliary fuel reforming catalyst is located inside the double pipe, and the stack unreacted fuel is supplied to the outside of the double pipe. And supply the heat source using the cathode outlet gas of the fuel cell stack discharged into the high temperature box.

In one aspect of the invention, the third catalytic combustor comprises a branched piping, the branched piping allowing the stack unreacted fuel to be uniformly distributed throughout the auxiliary fuel reformer to prevent local overheating.

According to one of the problem solving means of the solid oxide fuel cell system of the present invention described above, a valve is installed at a portion where the heat exchange is completed by branching the pipe where the combustion gas is discharged by the main portion where the heat exchange takes place, and each branched pipe By regulating the flow rate inside the system by the differential pressure applied to, the temperature control inside the system can be facilitated.

In addition, by installing an electric valve and measuring the temperature of the main part so that the temperature can be automatically controlled according to the operating state of the system, it can secure safety during operation and contribute to the improvement of system performance and durability.

1 is a view showing the configuration of a solid oxide fuel cell system according to the present invention.
2 is a diagram illustrating a configuration of a solid oxide fuel cell system according to another exemplary embodiment of the present invention.
3 is a diagram illustrating a detailed structure of a third catalytic combustor and an auxiliary fuel reformer according to an embodiment of the present invention.

The present invention may be variously modified and have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail with reference to the accompanying drawings.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In addition, the numbers (eg, first, second, etc.) used in the description process of the present specification are merely identification symbols for distinguishing one component from another component.

Also, in this specification, when an element is referred to as being "connected" or "connected" with another element, the element may be directly connected or directly connected to the other element, It should be understood that, unless an opposite description is present, it may be connected or connected via another element in the middle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing the configuration of a solid oxide fuel cell system according to the present invention.

The solid oxide fuel cell system 100 according to the present invention includes a high temperature box 110, a stack 111, a fuel reformer 112a, a fuel pre-reformer 113, a vaporizer 114, an air preheater 115, a first Catalytic combustor 116a, second catalytic combustor 116b, fuel reforming preheater 117, first heat exchanger 118a, second heat exchanger 118b, third heat exchanger 118c, fourth heat exchanger ( 120, igniter 130, vaporizer outlet valve 140, unreacted fuel outlet valve 150, air preheater outlet valve 160, first gas-liquid separator 171, second gas-liquid separator 172, and hot water Storage tank 180.

In describing each component, the hot box 110 includes a stack 111, a fuel reformer 112a, a vaporizer 114, a first and second catalytic combustors 116a and 116b, and a first, second and third heat exchanger ( 118a to 118c) to provide thermal insulation to maintain the operating temperature of components operating at high temperatures, and to minimize heat losses during heat exchange to improve system efficiency.

For reference, the first, second, third, and fourth heat exchangers 118a to 118c and 120 may use hot water heat exchangers, hereinafter, the first, second, third, and fourth heat exchangers 118a to 118c and 120. For example, use a hot water heat exchanger.

In addition, the cathode (cathode of the fuel cell) outlet gas of the stack 111 was discharged into the hot box 110 after providing the required amount of heat to the fuel reformer 112a, and then the first catalytic combustor 116a and the second catalyst. It is supplied to the combustor 116b to combust the stack unreacted fuel.

To this end, the high temperature box 110 may maintain the gas tightness within a high heat insulating property and a constant pressure, and the pipe and the measuring line inlet may also be sealed using a high temperature gasket.

In addition, an electric heating element may be installed inside the high temperature box 100 for the initial temperature raising and temperature control of the solid oxide fuel cell system 100.

For reference, the solid oxide fuel cell may use a variety of fuels, the present invention will be described an embodiment using the fuel NG or LPG.

On the other hand, the fuel supplied by using a compressor (not shown) or a Mass Flow Controller (MFC) (not shown) is passed through a desulfurizer (not shown) and then mixed with the steam generated in the vaporizer 114, fuel pre-reformer 113 Is supplied.

In this case, the water required for the reforming reaction may be supplied to the vaporizer 114 using a pump in the first gas-liquid separator 171, and then the vaporizer 114 may supply the stack unreacted fuel in the first catalytic combustor 116a. By exchanging heat with the combustion gas produced | generated, hot steam can be produced | generated.

On the other hand, the fuel pre-reformer 113 decomposes steam and hydrocarbon fuel into methane and hydrogen by a catalytic reaction, the heat required at this time may be supplied by the steam generated in the vaporizer 114.

Subsequently, the reactant after the fuel preliminary reforming reaction is preheated by heat exchange with a stack unreacted fuel having a high temperature (700 to 750 ° C.) in the fuel reforming preheater 117, and then undergoes steam reforming reaction in the fuel reformer 112a. It is supplied to the inlet of the anode (fuel cell anode) of the stack 111.

For reference, the amount of heat required for the fuel reforming reaction may be supplied through heat exchange with the cathode outlet gas at a high temperature (700-750 ° C.).

Meanwhile, the hot exhaust gas generated by stack unreacted fuel combusted in the second catalytic combustor 116b undergoes heat exchange while passing through the air preheater 115 to preheat the air supplied to the stack 111.

Here, the distribution of the unreacted fuel stack may vary depending on the opening angles of the stack unreacted fuel outlet valve 150, the vaporizer outlet valve 140, and the air preheater outlet valve 160.

Under normal operating conditions, the stack unreacted fuel outlet valve 150 is closed completely so that the stack unreacted fuel flows only to the piping with the first catalytic combustor 116a and the second catalytic combustor 116b.

If the temperature of the vaporizer 114 and the fuel pre-reformer 113 is low, vaporization

Opening more air outlet valve 140 reduces the differential pressure in the pipe branched to the first catalytic combustor 116a so that a larger amount of unreacted fuel can flow into the first catalytic combustor 116a.

Thus, a larger amount of unreacted fuel is burned, thus allowing more heat to be supplied to the vaporizer 114.

In addition, when the air inlet temperatures of the air preheater 115 and the stack 111 are low, the air preheater outlet valve 160 may be opened more to reduce the differential pressure in the pipe branched to the second catalytic combustor 116b. .

Thus, a larger amount of unreacted stack of fuel enters the second catalytic combustor 116b and the temperature of the air preheater 115 rises.

As described above, the cathode outlet gas of the stack 111 stays inside the hot box 110 after supplying the required amount of heat to the fuel reformer 112a, and then the vaporizer outlet valve 140 and the air preheater outlet valve 160. Due to the pipe differential pressure change according to the opening condition of the first catalytic combustor 116a and the second catalytic combustor 116b may be branched out after combustion and discharged to the outside.

In addition, when the temperature of the pipes branched into the stack 111, the air preheater 115, and the vaporizer 114 inside the hot box 110 is all overheated, the stack unreacted fuel outlet valve 150 is opened for temperature control. It is available.

For example, when the stack unreacted fuel outlet valve 150 is opened, the differential pressure in the pipe branching there is reduced so that a portion of the stack unreacted fuel does not pass through the first catalytic combustor 116a and the second catalytic combustor 116b. May be discharged to the outside through the stack unreacted fuel outlet valve 150.

Therefore, the amount of fuel burnt in the high temperature box 110 may be reduced, thereby lowering the internal temperature.

On the other hand, the solid oxide fuel cell system 100 according to an embodiment of the present invention is easy to heat generation power generation through hot water production as well as power generation due to high temperature operation.

In the embodiment of the present invention to improve the thermal efficiency through the production of hot water, and to lower the exhaust gas temperature discharged through the vaporizer outlet valve 140, the stack unreacted fuel outlet valve 150, the air preheater outlet valve 160. The first, second, third and fourth heat exchangers 118a to 118c and 120 for producing hot water can be used.

For example, the water stored in the hot water storage tank 180 may be supplied to the first hot water heat exchanger 118a by a pump (not shown) to lower the temperature of the gas discharged to the vaporizer outlet valve 140.

In addition, the water stored in the hot water storage tank 180 may lower the temperature of the gas discharged from the second hot water heat exchanger (118b) to the stack unreacted fuel outlet valve 150, the third hot water heat exchanger (118c) In this case, the temperature of the gas discharged to the air preheater outlet valve 160 may be lowered.

Thereafter, the water stored in the hot water storage tank 180 undergoes heat exchange with the exhaust gas combusted by the igniter 130 in the fourth hot water heat exchanger 120 outside the high temperature box 110, and then again, the hot water storage tank 180. Gathered in).

In addition, the stack unreacted fuel discharged to the outside through the stack unreacted fuel outlet valve 150 removes moisture from the second gas-liquid separator 172 and then burns with outside air in the igniter 130, and the fourth hot water The hot water may be manufactured in the heat exchanger 120 and then cooled to room temperature and then discharged to the atmosphere.

For reference, the circulation pipe of the hot water is preferably passed through the gasket used for the pipe connection for airtightness of the hot box 110 as well as the hot water heat exchanger.

In addition, the arrangement of the main components in the high temperature box 110 is arranged in the stack 111, the fuel reformer 112a on the top in consideration of the convection phenomenon and the operating temperature in the high temperature box 110, the heat exchange proceeds Therefore, a part having a lower temperature can be disposed below.

In addition, since both the stack unreacted fuel and the combustion gas contain a large amount of water, the stack is cooled to room temperature so that only the water may be collected in the first gas-liquid separator 171 and the second gas-liquid separator 172, and the collected water may be pumped. It can be used in the circulation process is supplied back to the vaporizer 114 is supplied to the fuel reforming.

2 is a diagram illustrating a configuration of a solid oxide fuel cell system 100 according to another exemplary embodiment of the present invention.

A third catalytic combustor 116c and an auxiliary fuel reformer 112b have been added to the solid oxide fuel cell system 100 to more effectively control the temperature of the fuel reformer 112a and stack 111.

The fuel reformer 112a is required to supply heat to a place where an endothermic reaction occurs, and the heat supply is not sufficient only by the amount of heat of the cathode outlet gas of the stack 111.

As a result, when the temperature of the fuel reformer 112a is lowered, hydrocarbons such as methane, which are not converted into hydrogen, may be supplied to the stack 111. In this case, an internal reforming reaction may occur in the stack 111 so that the stack 111 may be formed. The operating temperature of the stack is lowered, so that not only the performance of the normal stack 111 may not be obtained, but a vicious cycle may occur such that the temperature of the cathode exit gas of the stack 111 is lowered, resulting in a poor reforming reaction.

Accordingly, the solid oxide fuel cell system 100 according to another embodiment of the present invention may further control the third catalytic combustor 116c and the auxiliary fuel reformer 112b to more effectively control the temperature of the fuel reformer 112a and the stack 111. ) May be further included.

Hereinafter, the third catalytic combustor 116c and the auxiliary fuel reformer 112b will be described in detail.

As shown in FIG. 2, piping may be further added to allow a portion of the stack unreacted fuel that has passed through the fuel reforming preheater 117 to be supplied to the third catalytic combustor 116c.

In this case, the length and diameter of the pipe is preferably designed in consideration of the differential pressure applied to the pipe branched to the first catalytic combustor 116a and the second catalytic combustor 116b.

If the temperature of the fuel reformer 112a and the stack 111 drops, the stack unreacted fuel outlet valve 150 is locked and the opening angles of the air preheater outlet valve 160 and the carburetor outlet valve 140 are simultaneously reduced. As a result, the pressure of the pipes branched to them increases, so that the stack unreacted fuel flowing to the pipes branched to the third catalytic combustor 116c increases.

Accordingly, the combustion heat additionally generated in the third catalytic combustor 116c may activate the reforming reaction in the auxiliary fuel reformer 112b and raise the temperature of the fuel reformer 112a and the stack 11.

For reference, the carburetor outlet valve 140, the stack unreacted fuel outlet valve 150, and the air preheater outlet valve 160 may all be configured as electric valves. By making it possible, it is possible to ensure safety during system operation and to improve the performance and durability of the system.

3 is a diagram illustrating the detailed structure of the third catalytic combustor 116c and the auxiliary fuel reformer 112b according to an embodiment of the present invention.

As shown in FIG. 3, the third catalytic combustor 116c and the auxiliary fuel reformer 112b according to the exemplary embodiment of the present invention may be manufactured as an integrated structure of a double pipe.

An auxiliary fuel reformer 112b in which a reforming reaction of a part of a reactant that passes through the fuel reforming preheater 117 occurs is located in the inner pipe, and a third catalytic combustor 116c is wrapped in an outer pipe of the auxiliary fuel reformer 112b.

Combustion occurs using the cathode outlet gas of the stack 111 supplied to the stack unreacted fuel and discharged into the high temperature box 110.

In this case, a branched pipe may be added to the third catalytic combustor 116c to uniformly distribute the stack unreacted fuel throughout the auxiliary fuel reformer 112b to prevent local overheating.

As described above, the present invention branches a plurality of exhaust pipes of the cathode outlet gas of the stack 111 remaining in the stack unreacted fuel and the high temperature box 110 for temperature control of the solid oxide fuel cell system 100. Then, the combustion high temperature exhaust gas is passed through the branched pipe and sufficiently cooled through heat exchange necessary for preheating the reactant and producing hot water, and then may be discharged to the outside of the high temperature box 110.

At this time, the outside of the high temperature box 110 of the branched pipe has an electric valve, that is, the opening angle is adjusted, that is, the vaporizer outlet valve 140, the stack unreacted fuel outlet valve 150, the air preheater outlet valve 160 is branched The temperature inside the system can be controlled by adjusting the differential pressure of the finished pipe by controlling the flow rate of the exhaust gas passing through the pipe.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

100: Solid Oxide Fuel Cell System
110: high temperature box
111: stack
112a: fuel reformer, 112b: auxiliary fuel reformer
113: fuel reserve reformer
114: carburetor
115: air preheater
116a: first catalytic combustor, 116b second catalytic combustor, 116c third catalytic combustor
117: fuel reforming preheater
118a: first hot water heat exchanger, 118b: second hot water heat exchanger
118c: third hot water heat exchanger, 120: fourth hot water heat exchanger
130: igniter
140: carburetor outlet valve
150: stack unreacted fuel outlet valve
160: air preheater outlet valve
171: first gas-liquid separator
172: second gas-liquid separator
180: hot water storage tank

Claims (10)

In a solid oxide fuel cell system,
In an interior space, a fuel cell stack and a fuel reformer, first and second catalytic combustors connected to the fuel reformer, a vaporizer connected to the first catalytic combustor, an air preheater connected to the second catalytic combustor, a first heat exchanger connected to the vaporizer A high temperature box including a second heat exchanger connected to the fuel cell stack, a third heat exchanger connected to the air preheater, and having a heat insulation and airtight function;
A vaporizer outlet valve located outside of the hot box and connected to the first heat exchanger, a stack unreacted fuel outlet valve connected to the second heat exchanger, and an air preheater outlet valve connected to the third heat exchanger.
Including but not limited to:
Stack unreacted fuel and the internal air of the hot box supply the required amount of heat to the interior of the hot box through the heat exchanger, and the vaporizer outlet valve, the stack unreacted fuel outlet valve, and the air preheater outlet valve open each valve. And controlling the distribution of the stack unreacted fuel and the internal temperature of the hot box by adjusting the differential pressure of each pipe according to the angle.
The method of claim 1,
The fuel cell stack and the fuel reformer are located at an upper portion of the inner space of the hot box, the first and second catalytic combustors are located at the bottom of the fuel cell stack and the fuel reformer, and the vaporizer and the air preheater are located in the first, Located in parallel at the bottom of the two catalytic combustor, the first, second, third heat exchanger is disposed in parallel at the bottom of the first, second catalytic combustor in consideration of the convection phenomenon and operating temperature inside the hot box. Solid oxide fuel cell system.
The method of claim 1,
The hot box is a third catalytic combustor and auxiliary fuel reformer
Further comprising:
The third catalytic combustor combusts a portion of the stack unreacted fuel, and the auxiliary fuel reformer activates a reforming reaction according to the partial combustion of the stack unreacted fuel to control the temperature of the fuel cell stack and the fuel reformer, Solid oxide fuel cell system.
The method of claim 1,
An igniter located outside the hot box and combusting the stack unreacted fuel discharged to the outside through the stack unreacted fuel outlet valve;
A fourth heat exchanger for producing hot water due to the combustion of the igniter
Include more
The hot water production of the fourth heat exchanger lowers the temperature of the exhaust gas discharged through the vaporizer outlet valve, the stack unreacted fuel outlet valve, and the air preheater outlet valve.
The method of claim 1,
When the first, second and third heat exchangers produce hot water, the hot water production of the first, second and third heat exchangers is exhausted through the vaporizer outlet valve, the stack unreacted fuel outlet valve and the air preheater outlet valve. A solid oxide fuel cell system, each lowering the temperature of a gas.
The method of claim 1,
The cathode exhaust gas of the fuel cell stack stays inside the hot box and is combusted with the stack unreacted fuel in the first and second catalytic combustors to provide a high temperature exhaust gas.
The method of claim 1,
And the stack unreacted fuel outlet valve controls a temperature when a temperature of a pipe connected to the fuel cell stack, an air preheater, and a vaporizer is overheated.
The method of claim 7, wherein
When the valve of the stack unreacted fuel outlet is opened, the differential pressure of the pipe connected to the stack unreacted fuel outlet valve is reduced so that a part of the stack unreacted fuel is discharged to the outside without passing through the first and second catalytic combustors, Wherein the amount of fuel burnt inside the hot box is reduced to control the internal temperature of the hot box.
The method of claim 3, wherein
The third catalytic combustor and the auxiliary fuel reformer are an integral structure of a double pipe, wherein the auxiliary fuel reforming catalyst is located inside the double pipe, and the stack unreacted fuel is supplied to the outside of the double pipe to the inside of the hot box. And a heat source is supplied using the cathode outlet gas of the discharged fuel cell stack.
The method of claim 9,
Wherein the third catalytic combustor comprises a branched piping, the branched piping such that the stack unreacted fuel is uniformly distributed throughout the auxiliary fuel reformer to prevent local overheating.

Images