Fuel cell device and control method thereof

Abstract

The fuel cell device of the present application includes: a stack; a reformer; a burner; a water supply tank; a burner blower; a main air supply flow path; a vortex tube; a three-way valve that selectively supplies air sent from the burner blower to the main air supply flow path or the vortex tube; a four-way valve that switches a first switching flow path and a second switching flow path to discharge heated air and cooled air discharged from the vortex tube; a first heat exchanger that heat-exchanges cooling water discharged from the water supply tank and air discharged from the first switching flow path; a cooling water flow path that supplies the cooling water that has passed through the first heat exchanger to the stack; a first air supply flow path that supplies the air that has passed through the first heat exchanger to the burner; a second heat exchanger that heat-exchanges reforming gas discharged from the reformer and air discharged from the second switching flow path; a reforming gas flow path that supplies the reforming gas that has passed through the second heat exchanger to the stack; and a second air supply flow path that supplies the air that has passed through the second heat exchanger to the burner.

Description

Technical Field

[0001] This invention relates to fuel cell devices and control methods thereof, and more specifically, to a fuel cell device capable of using vortex tubes to control the temperature of cooling water and reformed gas. Background Technology

[0002] A fuel cell apparatus is a power generation device that produces electricity by electrochemically reacting hydrogen and oxygen contained in hydrocarbons such as methanol, ethanol, and natural gas.

[0003] Similar to prior art 1 (Korean Patent Publication No. 10-2012-0071288), existing fuel cell devices include: a fuel processing device that reforms fuel containing hydrogen atoms into hydrogen gas; and a stack that uses the hydrogen gas supplied from the fuel processing device to generate electrical energy. Additionally, the fuel cell device may also include a heat exchanger for cooling the stack and recovering heat, cooling water piping, and a power conversion device for converting the generated direct current power into alternating current power.

[0004] Since oxygen is required for the combustion of fuel gases in the burner of the fuel processing unit or for the generation of electricity in the fuel stack, similar to prior art 2 (Korean Patent Publication No. 10-1951439), fuel cell devices typically include a blower that directs external air to the fuel processing unit or fuel stack.

[0005] In the existing fuel cell device, it first operates in a preheating mode. In this mode, a reformer, which receives fuel gas and generates reforming gas required for power generation in the fuel cell stack, is heated by a burner to a temperature suitable for reforming. Then, it operates in a reforming mode. In this mode, if the reformer reaches the temperature condition, the reforming gas generated in the reformer is recycled back to the burner and reformed repeatedly until the concentration of hydrogen, carbon monoxide, etc., in the generated reforming gas reaches a concentration suitable for power generation in the fuel cell stack. Then, it can operate in a power generation mode. In this mode, if the concentration of the reforming gas reaches the concentration condition, the reforming gas and external air are supplied to the fuel cell stack to generate electricity by inducing an electrochemical reaction.

[0006] At this point, the fuel cell stack typically exhibits the best power generation efficiency at a temperature of approximately 75 degrees Celsius. In the case of the prior art, only when power generation begins will the high-temperature reforming gas and the cooling water heated by heat exchange with the reforming gas be supplied to the fuel cell stack and begin preheating. Therefore, there is a problem that the power generation efficiency decreases in the early stages of power generation operation due to the low temperature of the fuel cell stack.

[0007] On the other hand, as the fuel cell device generates electricity, heat is produced in the stack. This heat can reach a temperature suitable for the stack to generate electricity in the early stages of power generation, but after the stack reaches the target temperature, it needs to be cooled to prevent the stack from being overheated.

[0008] In existing fuel cell devices, when the power generation mode is maintained for a certain period of time and the stack reaches the target temperature, it is necessary to dissipate the heat generated by the operation of the fuel cell device. However, since the hot water in the water tank that is used to recover heat and store the heat by circulating cooling water according to the operation of the fuel cell device is discharged to the outside and then cold water is supplied again from an external water source, it is difficult to achieve precise thermal management of the fuel cell device and additional operating costs caused by water supply are generated.

[0009] Existing technical documents

[0010] Patent documents

[0011] Patent Document 1: KR10-2012-0071288A

[0012] Patent Document 2: KR10-1951439B Summary of the Invention

[0013] The purpose of this invention is to provide a fuel cell device that improves power generation efficiency by shortening the time required to preheat the fuel cell stack to a temperature suitable for power generation.

[0014] Another object of the present invention is to provide a fuel cell device that can simply and effectively dissipate waste heat generated in the fuel cell stack to maintain an optimal temperature.

[0015] Another object of the present invention is to provide a fuel cell device that improves the combustion efficiency of the burner or the power generation efficiency of the fuel cell by increasing the density of reforming gas supplied to the burner or fuel cell stack.

[0016] Another object of the present invention is to provide a fuel cell device that improves the combustion efficiency of the burner by increasing the density of the air supplied to the burner.

[0017] Another object of the present invention is to provide a fuel cell device that can precisely manage the temperature of the cooling water supplied to the fuel cell stack to an optimal temperature.

[0018] Another object of the present invention is to provide a fuel cell device that can precisely manage the temperature of reformed gas supplied to the burner or stack to an optimal temperature.

[0019] The subject matter of this invention is not limited to the subject matter mentioned above, and those skilled in the art can clearly understand other subject matters not mentioned from the following description.

[0020] To achieve the above-mentioned objectives, the fuel cell device of the present invention includes: a stack; a reformer for generating reformed gas and supplying it to the stack; a burner for heating the reformer; a water tank for storing cooling water to be supplied to the stack; a burner blower for drawing in external air and supplying it to the burner; a vortex tube for converting air into heated air and cooled air; and a three-way valve for selectively supplying air from the burner blower to the vortex tube or the burner.

[0021] Additionally, the fuel cell device includes: a first heat exchanger for exchanging heat between air discharged from the vortex tube and cooling water supplied from a water tank to the stack, and then supplying it to the burner; a second heat exchanger for exchanging heat between air discharged from the vortex tube and reformed gas discharged from the reformer, and then supplying it to the burner; and a four-way valve for supplying heated air and cooling air discharged from the vortex tube to different heat exchangers in the first and second heat exchangers.

[0022] The fuel cell device may further include: a reformed gas bypass path for supplying reformed gas discharged from the reformer and passing through the second heat exchanger to the burner; and a reformed gas bypass valve disposed in the reformed gas bypass path and capable of being opened or closed.

[0023] Therefore, the cooling water discharged from the water supply tank is preheated by exchanging heat with heated air in the first heat exchanger, and then supplied to the fuel cell stack. The preheated cooling water transfers heat to the fuel cell stack, thereby enabling the fuel cell stack to be quickly preheated to a temperature suitable for power generation.

[0024] In addition, the reformed gas generated and discharged in the reformer is cooled by exchanging heat with cooling air in the second heat exchanger and then supplied to the burner or fuel cell stack. The reformed gas with increased density is supplied to the burner or fuel cell stack, thereby improving the combustion efficiency of the burner and the power generation efficiency of the fuel cell stack.

[0025] In addition, to prevent unnecessary heat exchange between the cooling water and reforming gas, which have reached suitable temperatures for power generation, in the first and second heat exchangers, the air supplied from the burner blower can be switched to the burner instead of the vortex tube by switching the three-way valve. This maintains the optimal temperature of the cooling water and reforming gas, thereby maintaining the high power generation efficiency of the fuel cell stack.

[0026] The fuel cell device may further include: a reformed gas heat exchanger, which allows cooling water that has been heat-exchanged in a first heat exchanger and reformed gas that has been heat-exchanged in a second heat exchanger to exchange heat, and then supply them to the fuel cell stack respectively; a first bypass flow path, which allows air supplied from the vortex tube to the first heat exchanger to bypass the first heat exchanger; a first bypass valve, disposed in the first bypass flow path, which is capable of opening or closing; a second bypass flow path, which allows air supplied from the vortex tube to the second heat exchanger to bypass the second heat exchanger; and a second bypass valve, disposed in the second bypass flow path, which is capable of opening or closing.

[0027] Therefore, by bypassing the second heat exchanger, the cooling air is prevented from losing heat to the reformed gas as it passes through the second heat exchanger. As a result, the reformed gas is supplied to the reformed gas heat exchanger without heat loss and exchanges heat with the cooling water, thereby effectively preheating the cooling water passing through the reformed gas heat exchanger.

[0028] In addition, by opening the first bypass valve to prevent the supply of heated air to the first heat exchanger, or by switching the four-way valve to allow the supply of cooling air to the first heat exchanger, the cooling water passing through the first heat exchanger is prevented from being preheated or cooled, thereby enabling the cooling water to be kept at an appropriate temperature without being overheated.

[0029] Detailed descriptions of other embodiments are provided in the accompanying drawings.

[0030] In the fuel cell device of this embodiment of the invention, the three-way valve is controlled in the preheating operation mode of operating the burner to preheat the reformer, so that the air delivered from the burner blower is supplied to the burner instead of the vortex tube, thereby eliminating unnecessary pressure loss of the air supplied to the burner.

[0031] In the fuel cell device of this embodiment of the invention, during the reforming operation mode in which repeated reforming is performed to sufficiently reduce the carbon monoxide concentration of the reformed gas generated in the reformer, a three-way valve is controlled to supply air from the burner blower to the vortex tube. A four-way valve is controlled to supply heated air discharged from the vortex tube to the first heat exchanger and cooling air to the second heat exchanger. By closing the first and second bypass valves, cooling water is preheated by exchanging heat with the heated air in the first heat exchanger and then supplied to the fuel cell stack. The preheated cooling water transfers heat to the fuel cell stack, thereby enabling the fuel cell stack to be quickly preheated to a temperature suitable for power generation.

[0032] Furthermore, in the fuel cell device of this embodiment of the invention, the reformed gas generated and discharged in the reformer is cooled by exchanging heat with cooling air in the second heat exchanger and then supplied to the burner, thereby enabling the supply of reformed gas with increased density to the burner, thereby improving the combustion efficiency of the burner.

[0033] In the fuel cell device of this embodiment of the invention, in the power generation operation mode of supplying reformed gas and external air to the stack and generating electricity, the cooling water that is simultaneously preheated by the heated air through the first heat exchanger is further preheated by the reformed gas in the reformed gas heat exchanger and then supplied to the stack. The preheated cooling water transfers heat to the stack, thereby enabling the stack to be quickly preheated to a temperature suitable for power generation.

[0034] Furthermore, in the fuel cell device of this embodiment of the invention, the reformed gas, which is simultaneously cooled by cooling air through a second heat exchanger, is further cooled by cooling water in a reformed gas heat exchanger and then supplied to the fuel cell stack. The increased density of the reformed gas supplied to the fuel cell stack thereby improves the power generation efficiency of the fuel cell stack.

[0035] In the fuel cell device of this embodiment of the invention, during the power generation operation mode, the first bypass valve is closed and the second bypass valve is opened, thereby causing the heated air supplied to the burner to be cooled by heat exchange with cooling water in the first heat exchanger and then supplied to the burner. The cooled air supplied to the burner bypasses the second heat exchanger and is supplied to the burner while maintaining a low temperature. The air with increased density is supplied to the burner, thereby improving the combustion efficiency of the burner.

[0036] Furthermore, in the fuel cell device of this embodiment, when the reformed gas discharged from the reformer is supplied to the reformed gas heat exchanger through the second heat exchanger, the cooling air bypasses the second heat exchanger. Therefore, the reformed gas will not have its heat carried away by the cooling air in the second heat exchanger. Thus, it is supplied to the reformed gas heat exchanger at a high temperature and exchanges heat with the cooling water, thereby effectively preheating the cooling water passing through the reformed gas heat exchanger. This allows the fuel cell stack to be preheated to a temperature suitable for power generation more quickly.

[0037] In the fuel cell device of this embodiment of the invention, during the execution of the power generation operation mode, the four-way valve is controlled so that the heated air discharged from the vortex tube is supplied to the second heat exchanger and the cooling air is supplied to the first heat exchanger. The cooling water is cooled by exchanging heat with the cooling air in the first heat exchanger and is then supplied to the fuel cell stack. Thus, the cooling water can effectively absorb the heat generated by the electrochemical reaction of the fuel cell stack and keep the cooling water at an appropriate temperature without being overheated.

[0038] Furthermore, in the fuel cell device of this embodiment of the invention, the reformed gas is cooled for the first time by exchanging heat with cooling air in a second heat exchanger, and is further cooled by exchanging heat with cooling water in a reformed gas heat exchanger before being supplied to the fuel cell stack. This supplies the fuel cell stack with reformed gas of increased density, thereby improving the power generation efficiency of the fuel cell stack.

[0039] In the fuel cell device of this embodiment of the invention, during the execution of the power generation operation mode, the four-way valve is controlled so that the heated air discharged from the vortex tube is supplied to the first heat exchanger and the cooling air is supplied to the second heat exchanger. The first bypass valve is controlled to open and the second bypass valve is controlled to close, thereby preventing the heated air from being supplied to the first heat exchanger. This prevents the cooling water passing through the first heat exchanger from exchanging heat with the heated air, thereby maintaining the temperature of the cooling water.

[0040] In the fuel cell device of this invention embodiment, if the cooling water and reformed gas reach a temperature suitable for power generation during the execution of the power generation operation mode, in order to prevent unnecessary heat exchange between the cooling water and reformed gas in the first heat exchanger and the second heat exchanger, the temperature of the cooling water and reformed gas is maintained by switching the three-way valve to the burner side, thereby maintaining the high power generation efficiency of the fuel cell stack.

[0041] The effects of this invention are not limited to those mentioned above, and those skilled in the art can clearly understand other effects not mentioned from the description of the claims. Attached Figure Description

[0042] Figure 1 This is a structural diagram of a fuel cell device according to an embodiment of the present invention.

[0043] Figure 2 This is a schematic diagram of the configuration of a fuel processing apparatus according to an embodiment of the present invention.

[0044] Figure 3 This is a diagram illustrating the preheating operation mode of the fuel cell device according to an embodiment of the present invention.

[0045] Figure 4 This is a diagram illustrating the reforming operation mode of a fuel cell device according to an embodiment of the present invention.

[0046] Figure 5 This is a diagram illustrating the cooling water preheating mode of a fuel cell device according to an embodiment of the present invention.

[0047] Figure 6 This is a diagram illustrating the overheating limitation mode of the cooling water in a fuel cell device according to an embodiment of the present invention.

[0048] Figure 7 This is a diagram illustrating the cooling water temperature stabilization and reformed gas cooling mode of the fuel cell device according to an embodiment of the present invention.

[0049] Figure 8 This is a diagram illustrating the normal operating mode of a fuel cell device according to an embodiment of the present invention.

[0050] Figure 9 and Figure 10This is a control flowchart of a fuel cell device according to an embodiment of the present invention. Detailed Implementation

[0051] The advantages and features of the present invention, as well as the methods of implementing them, become clear from the accompanying drawings and the embodiments described in the following detailed description. However, the invention is not limited to the embodiments disclosed below, but can be implemented in various forms different from each other; it is only provided that this disclosure is intended to make the invention complete and to fully inform those skilled in the art of the scope of the invention, which is defined by the scope of the claims. Throughout the specification, the same reference numerals refer to the same constituent elements.

[0052] The terminology used in this specification is for illustrative purposes and not for limiting the invention. In this specification, the singular includes the plural unless otherwise stated. The use of the terms "comprises" and / or "comprising" in this specification does not preclude the presence or addition of more than one other constituent element, step, and / or action.

[0053] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) are to be used in the sense that is commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, terms defined in common dictionaries should not be interpreted ideally or excessively unless otherwise specifically defined.

[0054] The following is for reference Figure 1 The various parts of the fuel cell device 1 will be described.

[0055] The fuel cell device 1 may include a fuel processing unit I, a power generation unit II, a water circulation unit III, and / or a heat recovery unit IV. The fuel cell device 1 may also include a power conversion unit (not shown), which includes a power conversion device that converts the DC power generated by the power generation unit II into AC power.

[0056] The fuel treatment unit I may further include: a fuel treatment device 10; a fuel valve 30 for regulating the flow of fuel gas supplied to the fuel treatment device 10; and a burner blower 71 for directing air flow to the fuel treatment device 10.

[0057] The power generation unit II may include: fuel cell stacks 20a and 20b; a reforming gas heat exchanger 21 for performing heat exchange of reforming gas discharged from the fuel processing unit 10; a fifth heat exchanger 22 for performing heat exchange of gases discharged from the fuel cell stacks 20a and 20b that have not reacted; a humidification unit 23 for supplying moisture to the air supplied to the fuel cell stacks 20a and 20b; and a fuel cell stack blower 72 for directing airflow to the fuel cell stacks 20a and 20b. Here, the gases discharged from the fuel cell stacks 20a and 20b that have not reacted may be referred to as anode off gas (AOG). In one embodiment of the present invention, the fuel cell device 1 is described as having two fuel cell stacks 20a and 20b, but is not limited thereto.

[0058] The water circulation section III may include: a water supply tank 13 for storing water generated in the fuel cell unit 1; a water pump 38 for directing water to the fuel processing unit 10; a water supply valve 39 for regulating the flow of water supplied to the fuel processing unit 10; and a cooling water pump 43 for directing water to the reforming gas heat exchanger 21.

[0059] The heat recovery unit IV may include: a heat recovery tank 15 for storing water for heat exchange; and a heat recovery pump 48 for directing the water stored in the heat recovery tank 15 to the outside of the heat recovery tank 15; etc.

[0060] In order to help understand the core technical idea of ​​the present invention, specific constituent elements will first be described in a sequence that is independent of the order of operation of each part and each constituent element.

[0061] Reference Figures 1 to 3 The fuel cell device 1 of this embodiment includes: fuel cell stacks 20a and 20b; a reformer 140 that generates reformed gas and supplies it to fuel cell stacks 20a and 20b; a burner 120 that heats the reformer 140; a water tank 13 that stores cooling water supplied to fuel cell stacks 20a and 20b; a burner blower 71 that draws in external air and supplies it to the burner 120; a vortex tube 502 that converts air into heated air and cooled air; and a three-way valve 500 that selectively supplies air from the burner blower 71 to the vortex tube 502 or the burner 120.

[0062] Additionally, the fuel cell device 1 includes: a first heat exchanger 510 that supplies air discharged from the vortex tube 502 with cooling water supplied from the water supply tank 13 to the stacks 20a and 20b before supplying it to the burner 120; a second heat exchanger 520 that supplies air discharged from the vortex tube 502 with reformed gas discharged from the reformer 140 before supplying it to the burner 120; and a four-way valve 505 that supplies heated air and cooled air discharged from the vortex tube 502 to different heat exchangers in the first heat exchanger 510 and the second heat exchanger 520.

[0063] The fuel cells 20a and 20b generate electrical energy by causing an electrochemical reaction between hydrogen and oxygen. For example, the fuel cells 20a and 20b can generate electrical energy by causing an electrochemical reaction between hydrogen contained in reforming gas supplied from the fuel processing unit 10 and oxygen supplied as external air.

[0064] Stacks 20a and 20b can be constructed by stacking individual cells that induce electrochemical reactions. Each individual cell can consist of a membrane electrode assembly (MEA) with a fuel electrode and an air electrode arranged around an electrolyte membrane, as well as a separator. In the fuel electrode of the MEA, hydrogen is separated into hydrogen ions and electrons by a catalyst, thereby generating electricity. In the air electrode of the MEA, hydrogen ions and electrons can combine with oxygen to form water.

[0065] The reformer 140 can generate reformed gas by reforming the fuel gas to supply it to the fuel cell stacks 20a and 20b.

[0066] For example, the reformer 140 can utilize a catalyst to perform a reforming process that generates hydrogen from fuel gas after sulfur compounds have been removed. Here, the catalyst used for the reforming reaction can be a catalyst composed of nickel (Ni), alumina (Al2O3), or the like.

[0067] For example, fuel gas discharged from desulfurizer 110 and water vapor discharged from steam generator 130 can be mixed in second mixer 112 and supplied to reformer 140. At this time, when the fuel gas and water vapor supplied to reformer 140 undergo a reforming reaction in reformer 140, hydrogen can be generated.

[0068] On the other hand, the gas discharged from reformer 140 can be named reformed gas.

[0069] The burner 120 can heat the reformer 140 to promote the reforming reaction within the reformer 140. For example, fuel gas discharged from the desulfurizer 110 and air flowing in from the outside can be mixed in a first mixer 111 and supplied to the burner 120. At this time, the burner 120 can generate heat of combustion by burning the mixture of fuel gas and air, and the internal temperature of the reformer 140 can be maintained at an appropriate temperature (e.g., 800°C) by the heat supplied from the burner 120.

[0070] On the other hand, through the combustion of a gas mixture containing fuel gas and air, the exhaust gas generated in the burner 120 can be discharged to the outside of the fuel processing device 10. For example, the exhaust gas generated in the burner 120 of the fuel processing device 10 can be discharged from the fuel processing device 10 through the exhaust gas discharge path 210 and supplied to the third heat exchanger 26 for heat exchange, and then discharged to the outside.

[0071] The burner blower 71 can draw in and deliver outside air. The burner blower 71 can be connected to the first outside air inflow path 201 to draw in air flowing in through the first outside air inflow path 201. The burner blower 71 can be connected to the outflow path 201a to deliver the drawn-in outside air.

[0072] The outflow path 201a can be connected to the outlet of the burner blower 71 and the inlet of the three-way valve 500.

[0073] The three-way valve 500 can selectively supply air from the burner blower 71 to the main air supply path 202 or the vortex tube 502.

[0074] For example, the three-way valve 500 can be connected to the outlet flow path 201a, the main air supply flow path 202, and the vortex air supply flow path 501 in three directions. The three-way valve 500 can receive air supplied from the burner blower 71 through the outlet flow path 201a. The three-way valve 500 can be switched to discharge the received air to the main air supply flow path 202 or to the vortex air supply flow path 501.

[0075] The vortex air supply path 501 can be connected to the outlet of the three-way valve 500 and the inlet of the vortex tube 502.

[0076] The main air supply path 202 can connect the outlet of the three-way valve 500 and the fuel processing device 10 to supply air from the burner blower 71 to the burner 120. For example, the air supplied to the fuel processing device 10 through the main air supply path 202 can be mixed with the fuel gas discharged from the desulfurizer 110 in the first mixer 111 and then supplied to the burner 120.

[0077] The vortex tube 502 can convert the air delivered from the burner blower 71 into heated air and cooled air.

[0078] For example, the intake of the vortex tube 502 is connected to the vortex air supply path 501, through which air can be received and converted into heated air and cooled air. For example, the heated air outlet of the vortex tube 502 is connected to the hot air supply path 503, through which the heated air converted in the vortex tube 502 can be discharged. For example, the cooled air outlet of the vortex tube 502 is connected to the cold air supply path 504, through which the cooled air converted in the vortex tube 502 can be discharged.

[0079] The hot air supply path 503 connects the heated air outlet of the vortex tube 502 and the four-way valve 505, which allows the heated air discharged from the vortex tube 502 to be supplied to the four-way valve 505.

[0080] The cold air supply path 504 can be connected to the cooling air outlet of the vortex tube 502 and the four-way valve 505, so that the cooling air discharged from the vortex tube 502 can be supplied to the four-way valve 505.

[0081] The four-way valve 505 can switch the heated air and cooling air discharged from the vortex tube 502 to different flow paths in the first switching flow path 511 and the second switching flow path 521 and discharge them.

[0082] For example, the four-way valve 505 can be connected to the hot air supply path 503, the cold air supply path 504, the first switching path 511, and the second switching path 521 in four directions.

[0083] For example, the four-way valve 505 can be switched to discharge heated air received through the hot air supply path 503 to the first switching path 511 and to discharge cooled air received through the cold air supply path 504 through the second switching path 521 (hereinafter referred to as the "first switching mode"). Alternatively, the four-way valve 505 can be switched to discharge heated air received through the hot air supply path 503 to the second switching path 521 and to discharge cooled air received through the cold air supply path 504 through the first switching path 511 (hereinafter referred to as the "second switching mode").

[0084] The first switching flow path 511 can connect the outlet of the four-way valve 505 and the first heat exchanger 510. The second switching flow path 521 can connect the remaining outlet of the four-way valve 505 and the second heat exchanger 520.

[0085] The first heat exchanger 510 can exchange heat between cooling water discharged from the water supply tank 13 and air discharged from the first switching flow path 511. For example, the first heat exchanger 510 can receive cooling water discharged from the water supply tank 13 through the cooling water flow path 304 and exchange heat with it, and then the cooled water that has been heat-exchanged is discharged into the cooling water flow path 304.

[0086] For example, the first heat exchanger 510 can receive heated air (first switching mode) or cooled air (second switching mode) discharged from the vortex tube 502 and the four-way valve 505 through the first switching flow path 511 and exchange heat with it, and then discharge it to the first supply flow path 512.

[0087] Cooling water flow path 304 can supply cooling water that has passed through the first heat exchanger 510 to fuel cells 20a and 20b.

[0088] For example, the first heat exchanger 510 can be configured in the cooling water flow path 304, dividing the cooling water flow path 304 into a front end and a rear end. In this case, the front end of the cooling water flow path 304 can be connected to the water supply tank 13 and the first heat exchanger 510, supplying cooling water from the water supply tank 13 to the first heat exchanger 510. At the same time, the rear end of the cooling water flow path 304 can be connected to the first heat exchanger 510 and the reformer gas heat exchanger 21, so that the cooling water that has passed through the first heat exchanger 510 passes through the reformer gas heat exchanger 21 and is then supplied to the fuel cell stacks 20a and 20b.

[0089] A cooling water pump 43 that directs water stored in the water supply tank 13 to the first heat exchanger 510 and / or a cooling water flow meter 56 that detects the flow rate of water flowing in the cooling water flow path 304 may be configured at the front end of the cooling water flow path 304.

[0090] Cooling water pump 43 can supply cooling water stored in water supply tank 13 to fuel cells 20a and 20b.

[0091] The first air supply path 512 can supply air that has passed through the first heat exchanger 510 to the burner 120. The first air supply path 512 can connect the first heat exchanger 510 and the burner 120. One end of the first air supply path 512 can be connected to the first heat exchanger 510, and the other end of the first air supply path 512 can be merged into the main air supply path 202.

[0092] The first bypass flow path 513 can branch from and merge into the first supply flow path 512 from the first switching flow path 511. The first bypass valve 514 can be configured in the first bypass flow path 513 and can be opened so that air passing through the first switching flow path 511 bypasses the first heat exchanger 510.

[0093] Air passing through the first switching flow path 511 bypasses the first heat exchanger 510 as the first bypass valve 514 opens, and can be directly supplied to the first supply flow path 512 through the first bypass flow path 513.

[0094] The second heat exchanger 520 allows heat exchange between the reformed gas discharged from the reformer 140 and the air discharged from the second switching flow path 521. For example, the second heat exchanger 520 receives the reformed gas discharged from the reformer 140 through the reformed gas flow path 104 and exchanges heat with it, and then discharges the heat-exchanged reformed gas back to the reformed gas flow path 104.

[0095] For example, the second heat exchanger 520 can receive heated air (second switching mode) or cooled air (first switching mode) discharged from the vortex tube 502 and the four-way valve 505 through the second switching flow path 521 and exchange heat with it, and then discharge it to the second supply flow path 522.

[0096] The reformed gas flow path 104 can supply the reformed gas that has passed through the second heat exchanger 520 to the fuel cell stacks 20a and 20b.

[0097] For example, a second heat exchanger 520 can be configured in the reformed gas flow path 104, dividing the reformed gas flow path 104 into a front end and a rear end. The front end of the reformed gas flow path 104 can be connected to the fuel processing unit 10 and the second heat exchanger 520, supplying reformed gas from the reformer 140 to the second heat exchanger 520. The rear end of the reformed gas flow path 104 can be connected to the second heat exchanger 520 and the reformed gas heat exchanger 21, allowing the reformed gas that has passed through the second heat exchanger 520 to pass through the reformed gas heat exchanger 21 and then be supplied to the fuel cell stacks 20a and 20b.

[0098] The reformed gas bypass flow path 105 can branch off from the reformed gas flow path 104 and connect to the burner 120.

[0099] For example, the reformed gas bypass flow path 105 can branch off from the rear end of the reformed gas flow path 104 and connect to the burner 120. The reformed gas flowing into the burner 120 through the reformed gas bypass flow path 105 can be used as fuel for combustion in the burner 120.

[0100] The reforming gas bypass valve 34 can be configured in the reforming gas bypass flow path 105.

[0101] The reforming gas bypass valve 34 can be opened to supply reforming gas through reforming gas flow path 104 to burner 120 via reforming gas bypass flow path 105. Alternatively, the reforming gas bypass valve 34 can be closed to prevent reforming gas through reforming gas flow path 104 from passing through reforming gas bypass flow path 105.

[0102] The reforming gas valve 33 can be configured downstream of the location of the branch of the reforming gas bypass flow path 105 in the reforming gas flow path 104.

[0103] For example, the reforming gas valve 33 can be configured downstream of the point where the reforming gas bypass flow path 105 branches off at the rear end of the reforming gas flow path 104. The reforming gas valve 33 can be opened to supply reforming gas through the reforming gas flow path 104 to the reforming gas heat exchanger 21 and the fuel cell stacks 20a and 20b. Alternatively, the reforming gas valve 33 can be closed to prevent the supply of reforming gas through the reforming gas flow path 104 to the reforming gas heat exchanger 21 and the fuel cell stacks 20a and 20b.

[0104] The second air supply path 522 can supply air that has passed through the second heat exchanger 520 to the burner 120. The second air supply path 522 can connect the second heat exchanger 520 and the burner 120. One end of the second air supply path 522 can be connected to the second heat exchanger 520, and the other end of the second air supply path 522 can be merged into the main air supply path 202.

[0105] The second bypass flow path 523 can branch from and merge into the second supply flow path 522 from the second switching flow path 521. The second bypass valve 524 can be configured in the second bypass flow path 523 and can be opened so that air passing through the second switching flow path 521 bypasses the second heat exchanger 520.

[0106] Air passing through the second switching flow path 521 can bypass the second heat exchanger 520 as the second bypass valve 524 opens, and be directly supplied to the second supply flow path 522 through the second bypass flow path 523.

[0107] The reformed gas heat exchanger 21 enables heat exchange between cooling water flowing through cooling water path 304 and reformed gas flowing through reformed gas path 104.

[0108] The reformed gas heat exchanger 21 can be connected to the rear end of the reformed gas flow path 104 to receive reformed gas. The reformed gas heat exchanger 21 can also be connected to the rear end of the cooling water flow path 304 to receive cooling water. The reformed gas heat exchanger 21 enables heat exchange between the reformed gas received through the reformed gas flow path 104 and the cooling water received through the cooling water flow path 304.

[0109] The fuel cell stack gas supply path 106 can connect the reforming gas heat exchanger 21 and the fuel cell stacks 20a and 20b, and supply the reforming gas that has been heat-exchanged with cooling water in the reforming gas heat exchanger 21 to the fuel cell stacks 20a and 20b.

[0110] The fuel cell stack cooling water supply path 305 can be connected to the reforming gas heat exchanger 21 and the fuel cell stacks 20a and 20b, and will supply the cooling water after heat exchange with the reforming gas in the reforming gas heat exchanger 21 to the fuel cell stacks 20a and 20b.

[0111] The water supply tank 13 can store cooling water to be supplied to the fuel cells 20a and 20b. For example, the water supply tank 13 can be connected to the water inflow path 301 and can store cooling water supplied from an external water source (not shown) through the water inflow path 301. The water inflow path 301 can be equipped with a first liquid filter 92 to remove foreign matter contained in the externally supplied water and / or a water inflow valve 41 to regulate the flow of water into the water supply tank 13.

[0112] Cooling water can refer to ultrapure water that has been free of impurities. For ease of explanation, it will be described without explicitly distinguishing it from water.

[0113] The water supply tank 13 can be connected to the water discharge passage 302, through which at least a portion of the cooling water stored in the water supply tank 13 can be discharged to the outside. A water discharge valve 42 can be configured in the water discharge passage 302, which regulates the flow of cooling water discharged from the water supply tank 13.

[0114] At this time, the cooling water stored in the water supply tank 13 is discharged through the water discharge path 302, and cold cooling water is received from an external water supply source (not shown), thereby reducing the temperature of the cooling water stored in the water supply tank 13.

[0115] The water supply tank 13 can be connected to the water storage flow path 308, through which flowing cooling water can be stored. For example, cooling water discharged from the reformed gas moisture removal device 61, the additional moisture removal device 62, the AOG moisture removal device 63, and / or the air moisture removal device 64 and flowing through the third water recovery flow path 311 can flow into the water supply tank 13 via the water storage flow path 308. A second liquid filter 93 can be configured in the water storage flow path 308 to remove foreign matter contained in the cooling water returning to the water supply tank 13.

[0116] At least a portion of the cooling water stored in the water supply tank 13 can flow to the reformer gas heat exchanger 21 via the cooling water pump 43, where it can exchange heat with the reformer gas. The cooling water discharged from the reformer gas heat exchanger 21 can flow into the fuel cell stacks 20a and 20b via the fuel cell stack cooling water supply path 305.

[0117] The cooling water flowing into fuel cells 20a and 20b through the fuel cell cooling water supply path 305 can preheat or cool fuel cells 20a and 20b. The cooling water flowing into fuel cells 20a and 20b can absorb the heat generated by the electrochemical reactions that occur in fuel cells 20a and 20b.

[0118] Therefore, the cooling water stored in the water supply tank 13 is closely related to the temperature of the fuel cell stacks 20a and 20b. Thus, it is necessary to manage the temperature of the cooling water stored in the water supply tank 13 so that the fuel cell stacks 20a and 20b can reach and maintain a suitable temperature for power generation.

[0119] Multiple fuel cell stacks 20a and 20b can be connected via water connection path 306. Cooling water discharged from the first fuel cell stack 20a can flow into the second fuel cell stack 20b via water connection path 306.

[0120] Cooling water discharged from fuel cell stacks 20a and 20b can be supplied to the water supply tank 13 via cooling water recovery path 307. Alternatively, cooling water discharged from fuel cell stacks 20a and 20b can flow into the cooling water heat exchanger 24 via cooling water recovery path 307. The cooling water heat exchanger 24 allows for heat exchange between the cooling water discharged from fuel cell stacks 20a and 20b and the cooling water discharged from the heat recovery tank 15. The cooling water discharged from fuel cell stacks 20a and 20b is stored in the water supply tank 13 via the cooling water heat exchanger 24 and the water storage path 308.

[0121] The fuel cell stack blower 72 can draw in outside air and supply it to the fuel cell stacks 20a and 20b. The fuel cell stack blower 72 can be connected to a second external air inflow path 203, which is connected to the first external air inflow path 201, and a fuel cell-side air inflow path 204. The second external air inflow path 203 can be connected to the rear end of the air filter 91. The fuel cell stack blower 72 can cause the air flowing in through the second external air inflow path 203 to flow to the fuel cell side through the fuel cell-side air inflow path 204.

[0122] A second air-side check valve 82 that restricts the direction of air flow can be configured in the second external air inflow path 203.

[0123] The fuel cell stack air supply path can connect the fuel cell stack blower 72 and fuel cell stacks 20a and 20b. The fuel cell stack air supply path can include fuel cell side air inflow path 204, fuel cell side air supply path 205, and independent supply paths 206 and 207.

[0124] An air flow meter 53 may be configured in the air inflow path 204 on the fuel cell side, the air flow meter 53 detecting the flow rate of the air flowing in the air inflow path 204 on the fuel cell side.

[0125] The humidifier 23 can supply moisture to the air flowing in through the fuel cell side air inflow path 204 and can discharge moisture-containing air through the fuel cell side air supply path 205.

[0126] An internal valve 36 is configured in the fuel cell supply air path and can be opened or closed. For example, an internal valve 36 can be configured in the fuel cell side air supply path 205, which regulates the flow of air supplied to fuel cells 20a and 20b.

[0127] The fuel cell side air supply path 205 can be connected to independent supply paths 206 and 207 corresponding to fuel cell stacks 20a and 20b, respectively. Air flowing through the fuel cell side air supply path 205 can be supplied to fuel cell stacks 20a and 20b through independent supply paths 206 and 207.

[0128] The fuel cell stack exhaust path can connect fuel cell stacks 20a and 20b to the outside. The fuel cell stack exhaust path may include independent exhaust paths 208 and 209, air exhaust path 211, air discharge path 212, and exhaust path 213.

[0129] The fuel cell side air discharge path 211 can be connected to independent discharge paths 208 and 209 corresponding to fuel cells 20a and 20b, respectively. Air discharged from fuel cells 20a and 20b can flow to the fuel cell side air discharge path 211 through independent discharge paths 208 and 209. At this time, the air flowing through the fuel cell side air discharge path 211 may include moisture generated by the electrochemical reactions caused in fuel cells 20a and 20b.

[0130] The fuel cell side air discharge path 211 can be connected to the humidification device 23. The humidification device 23 uses the moisture contained in the air supplied through the fuel cell side air discharge path 211 to supply moisture to the air flowing into the fuel cell stacks 20a and 20b. The air supplied to the humidification device 23 through the fuel cell side air discharge path 211 can be discharged by the humidification device 23 to the air exhaust path 212.

[0131] An external valve 37 is configured in the fuel cell exhaust flow path and can be opened or closed. For example, an external valve 37 can be configured in the air discharge flow path 211 on the fuel cell side, and the external valve 37 regulates the flow of air discharged from the fuel cell 20a and 20b and flowing into the humidification device 23.

[0132] The fuel cell device 1 may also include a thermometer for sensing temperature and / or a pressure gauge for sensing pressure.

[0133] For example, the fuel cell device 1 may include a thermometer that senses the temperature of cooling water flowing in the hot water recovery flow path 317, a thermometer that senses the temperature of anode exhaust gas (AOG) discharged from the stacks 20a and 20b and flowing in the AOG discharge flow path 108, etc.

[0134] For example, fuel cell device 1 may include: a first temperature sensor 530 for sensing the temperature of cooling water discharged from stacks 20a and 20b; a second temperature sensor 531 for sensing the temperature of reforming gas supplied to stacks 20a and 20b; and a third temperature sensor 532 for sensing the temperature inside reformer 140.

[0135] For example, the fuel cell device 1 may include a pressure gauge that senses the pressure of reforming gas flowing into the stacks 20a and 20b, and a pressure gauge that senses the pressure of anode exhaust gas (AOG) discharged from the stacks 20a and 20b.

[0136] The fuel cell device 1 may include a concentration measurement sensor 534 that senses the concentration of carbon monoxide in the reformed gas generated and discharged in the reformer 140.

[0137] The fuel cell device 1 may also include at least one control unit (not shown). The control unit 440 may include at least one processor. Here, the processor may be a general-purpose processor such as a CPU (central processing unit). Of course, the processor may be a dedicated device such as an ASIC or a processor based on other hardware.

[0138] The control unit can control the overall operation of the fuel cell device 1. The control unit can be connected to each component installed in the fuel cell device 1 and can send and / or receive signals with each component. For example, the control unit can confirm the temperature of the burner 120, reformer 140, first reactor 150 and / or second reactor 160, cooling water discharged from stacks 20a and 20b, and reforming gas supplied to stacks 20a and 20b based on signals received from at least one thermometer included in the fuel cell device 1.

[0139] The control unit can process signals received from each component installed in the fuel cell device 1, and can send control signals based on the processed signals to each component installed in the fuel cell device 1. For example, the control unit can adjust the opening degree of each valve installed in the fuel cell device 1.

[0140] The following is for reference Figure 1 and Figure 2 The remaining configurations of the fuel cell device 1 according to an embodiment of the present invention will be described.

[0141] The fuel processing device 10 may include a desulfurizer 110, a burner 120, a steam generator 130, a reformer 140, a first reactor 150, and / or a second reactor 160. The fuel processing device 10 may also include at least one mixer 111, 112.

[0142] The desulfurizer 110 can perform a desulfurization process to remove sulfur-containing cooling water from fuel gas. For example, the desulfurizer 110 may contain an adsorbent. In this case, the sulfur-containing cooling water contained in the fuel gas passing through the interior of the desulfurizer 110 can be adsorbed onto the adsorbent. The adsorbent may be composed of metal oxides, zeolite, activated carbon, etc.

[0143] The desulfurizer 110 may also include a filter to remove foreign matter contained in the fuel gas.

[0144] Steam generator 130 can vaporize cooling water to discharge as steam. For example, steam generator 130 can receive heat from exhaust gas generated by burner 120, first reactor 150 and / or second reactor 160 to vaporize cooling water.

[0145] The steam generator 130 may be configured adjacent to the flow path for the exhaust gas flow from the first reactor 150, the second reactor 160 and / or the burner 120.

[0146] On the other hand, the first mixer 111 and / or the second mixer 112 can be implemented by an injector. For example, the second mixer 112 can be an injector that uses water vapor discharged from the steam generator 130 to draw fuel gas discharged from the desulfurizer 110 into its interior.

[0147] The first reactor 150 can reduce the amount of carbon monoxide generated by the reforming reaction in the components of the gas discharged from the reformer 140. For example, the carbon monoxide in the gas discharged from the reformer 140 can react with water vapor inside the first reactor 150 to produce carbon dioxide and hydrogen. In this case, the internal temperature of the first reactor 150 can be a temperature lower than the internal temperature of the reformer 140 but higher than room temperature (e.g., 200°C).

[0148] The first reactor 150 can be named a shift reactor.

[0149] The second reactor 160 can reduce the residual carbon monoxide in the components of the gas emitted from the first reactor 150. For example, it may cause the carbon monoxide in the gas emitted from the first reactor 150 to undergo a preferential oxidation (PROX) reaction with oxygen inside the second reactor 160.

[0150] On the other hand, a drawback of selective oxidation is that, due to the need for a large amount of oxygen, an additional air supply is required, which dilutes the hydrogen and reduces the concentration of hydrogen supplied to fuel cells 20a and 20b. Therefore, to overcome this drawback, a selective methanation reaction involving carbon monoxide and hydrogen can be utilized.

[0151] On the other hand, a reforming gas moisture removal device 61, which regulates the amount of moisture contained in the reforming gas, can be configured in the fuel cell gas supply flow path 106. After the moisture is removed, the reforming gas flowing into the reforming gas moisture removal device 61 can be discharged from the reforming gas moisture removal device 61.

[0152] The condensate generated in the reforming gas moisture removal device 61 can be discharged from the reforming gas moisture removal device 61 and flow to the first water recovery flow path 309. The first water recovery flow path 309 may be equipped with a first water recovery valve 44 for regulating the flow of cooling water.

[0153] Multiple fuel cell stacks 20a and 20b can be connected to each other via gas connection path 107. Unreacted reformed gas discharged from the first fuel cell stack 20a can flow into the second fuel cell stack 20b via gas connection path 107.

[0154] An additional moisture removal device 62 may be configured in the gas connection flow path 107 to remove condensate generated when the reformed gas is condensed during its passage through the first fuel cell stack 20a.

[0155] The condensate generated by the additional moisture removal device 62 can be discharged from the additional moisture removal device 62 and flow to the second water recovery flow path 310. The second water recovery flow path 310 can be equipped with a second water recovery valve 45 to regulate the flow of condensate. The second water recovery flow path 310 can be connected to the first water recovery flow path 309.

[0156] Unreacted anode exhaust gas (AOG) emitted from fuel cells 20a and 20b can flow through AOG discharge path 108.

[0157] The fifth heat exchanger 22 can be connected to the AOG discharge path 108, which supplies the anode exhaust gas (AOG) discharged from the fuel cells 20a and 20b. The fifth heat exchanger 22 can also be connected to the hot water supply path 313, which supplies the condensate discharged from the heat recovery tank 15. In the fifth heat exchanger 22, the anode exhaust gas (AOG) flowing in through the AOG discharge path 108 and the condensate supplied through the hot water supply path 313 can exchange heat.

[0158] The hot water supply path 313 may be equipped with a hot water pump 48 that directs the condensate stored in the heat recovery tank 15 to the fifth heat exchanger 22 and / or a hot water flow meter 55 that detects the flow rate of the condensate flowing in the hot water supply path 313.

[0159] The fifth heat exchanger 22 can be connected to the AOG supply path 109, through which the heat-exchanged anode exhaust gas (AOG) can be discharged. The anode exhaust gas (AOG) discharged from the fifth heat exchanger 22 can flow to the fuel processing unit 10 through the AOG supply path 109. The anode exhaust gas (AOG) supplied to the fuel processing unit 10 through the AOG supply path 109 can be used for combustion of fuel in the burner 120.

[0160] The AOG discharge path 108 and AOG supply path 109, which allow the anode exhaust gas from fuel cells 20a and 20b to flow toward the fuel processing unit 10, can be designated as AOG flow paths. In this case, the AOG discharge path 108 can be designated as the front end of the AOG flow path, and the AOG supply path 109 can be designated as the rear end of the AOG flow path.

[0161] An AOG supply path 109 may be configured with an AOG moisture removal device 63 to regulate the amount of moisture contained in the AOG and / or an AOG valve 35 to regulate the flow of the AOG supplied to the fuel treatment unit 10. The AOG flowing into the AOG moisture removal device 63 can be discharged from the AOG moisture removal device 63 after the moisture has been removed.

[0162] The condensate generated in the AOG moisture removal device 63 is discharged from the AOG moisture removal device 63 and can flow through the third water recovery flow path 311. A third water recovery valve 46 for regulating the flow of cooling water can be configured in the third water recovery flow path 311. The third water recovery flow path 311 can be connected to the first water recovery flow path 309.

[0163] The condensate pumped out of the heat recovery tank 15 by the hot water pump 48 can flow into the fifth heat exchanger 22 via the hot water supply path 313. The condensate after exchanging heat with the anode exhaust gas (AOG) in the fifth heat exchanger 22 can be discharged into the first hot water circulation loop 314.

[0164] The fourth heat exchanger 25 can be connected to the air outlet path 212 for air flowing from the humidifier 23. The fourth heat exchanger 25 can also be connected to the first hot water circulation loop 314 for cooling water flowing from the fifth heat exchanger 22. The fourth heat exchanger 25 allows heat exchange between the air flowing in through the air outlet path 212 and the cooling water flowing in through the first hot water circulation loop 314.

[0165] The air that has been heat-exchanged in the fourth heat exchanger 25 can be discharged from the fourth heat exchanger 25 through the exhaust flow path 213. The exhaust flow path 213 can be connected to the exhaust gas discharge flow path 210, and the exhaust gas flowing in the exhaust gas discharge flow path 210 and the air flowing in the air discharge flow path 212 can be mixed.

[0166] An air moisture removal device 64 may be configured in the exhaust flow path 213. The air moisture removal device 64 can adjust the amount of moisture contained in the air discharged to the outside. The air flowing into the air moisture removal device 64 can be discharged from the air moisture removal device 64 after the moisture is removed.

[0167] The condensate generated in the air moisture removal device 64 can be discharged from the air moisture removal device 64 and flow through the fourth water recovery flow path 312. A fourth water recovery valve 47 for regulating the flow of condensate can be configured in the fourth water recovery flow path 312. The fourth water recovery flow path 312 can be connected to the water storage flow path 308.

[0168] The cooling water that has undergone heat exchange in the fourth heat exchanger 25 can be discharged from the fourth heat exchanger 25 through the second hot water circulation path 315. The cooling water discharged from the fourth heat exchanger 25 can flow into the cooling water heat exchanger 24 through the second hot water circulation path 315.

[0169] The cooling water heat exchanger 24 allows water flowing in through the cooling water recovery flow path 307 and cooling water flowing in through the second hot water circulation flow path 315 to exchange heat.

[0170] The third heat exchanger 26 can be connected to the exhaust gas discharge path 210 for supplying exhaust gas. The third heat exchanger 26 can also be connected to the third hot water circulation path 316 for supplying cooling water discharged from the cooling water heat exchanger 24. The third heat exchanger 26 can facilitate heat exchange between the exhaust gas flowing in through the exhaust gas discharge path 210 and the cooling water flowing in through the third hot water circulation path 316.

[0171] The exhaust gas that has been heat-exchanged in the third heat exchanger 26 can be discharged into the exhaust flow path 213, and the exhaust gas flowing in the exhaust flow path 213 can be discharged to the outside.

[0172] The cooling water that has been heat-exchanged in the third heat exchanger 26 can be discharged to the hot water recovery flow path 317, and the cooling water flowing in the hot water recovery flow path 317 can flow into the heat recovery tank 15.

[0173] The following is for reference Figures 3 to 10 The control flowchart and operation mode of the fuel cell device 1 according to an embodiment of the present invention will be described.

[0174] If the fuel cell unit 1 starts operating, the burner blower 71 draws in and discharges outside air, and the air discharged from the burner blower 71 is supplied to the burner 120, supplying fuel to the burner 120. This allows for the execution of a preheating operation mode (S1) where the burner 120 is operated to preheat the reformer 140 (see reference). Figure 3 ).

[0175] Air supplied from the burner blower 71 can be delivered to the three-way valve 500 via the delivery flow path 201a. The control unit can control the three-way valve 500 so that the air supplied from the burner blower 71 is supplied to the main air supply flow path 202. Since the three-way valve 500 is switched to the main air supply flow path 202 side, the air supplied to the three-way valve 500 can be directly supplied to the burner 120 via the main air supply flow path 202 without being supplied to the vortex tube 502, thereby eliminating unnecessary pressure loss.

[0176] The burner 120 heats the reformer 140 by burning the fuel received and the air received through the main gas supply path 202. The combusted exhaust gas can be discharged to the outside through the exhaust gas discharge path 210.

[0177] The descriptions of the fuel supplied to burner 120, desulfurizer, and mixer, etc., are as described above, and therefore are omitted.

[0178] During the preheating operation mode, the control unit can determine whether the temperature value received from the third temperature sensor 532, which senses the internal temperature of the reformer 140, has reached the set reformer temperature value (S2).

[0179] At this time, the set reformer temperature value refers to the temperature suitable for the reforming reaction of fuel and steam in the reformer 140 to generate reformed gas, and can be a value pre-stored in the memory of the control unit.

[0180] If the internal temperature of the reformer 140 reaches the set reformer temperature value, the reforming operation mode (S3) can be executed. In this reforming operation mode, air discharged from the burner blower 71 is supplied to the vortex tube 502, allowing the cooling water discharged from the water supply tank 13 to exchange heat with the heated air discharged from the vortex tube 502. This air is then supplied to the fuel cell stacks 20a and 20b, where the reformed gas generated and discharged in the reformer 140 exchanges heat with the cooling air discharged from the vortex tube 502. This gas is then supplied to the burner 120, where the heated and cooled air that has undergone heat exchange is supplied (see reference). Figure 4 ).

[0181] Fuel and steam are supplied to reformer 140, whereby the fuel and steam undergo a reforming reaction to generate reformed gas. Descriptions of the fuel and steam, desulfurizer, mixer, and steam generator, etc., are as described above, and therefore are omitted.

[0182] Air supplied from the burner blower 71 can be delivered to the three-way valve 500 via the delivery flow path 201a. The control unit can control the three-way valve 500 so that the air supplied from the burner blower 71 is supplied to the vortex tube 502. Since the three-way valve 500 is switched to the vortex tube 502 side, the air supplied to the three-way valve 500 can be supplied to the vortex tube 502 via the vortex supply flow path 501.

[0183] The vortex tube 502 can convert the received air into heated air and cooled air and discharge them. The heated air discharged from the vortex tube 502 can be supplied to the four-way valve 505 through the hot air supply flow path 503. The cooled air discharged from the vortex tube 502 can be supplied to the four-way valve 505 through the cold air supply flow path 504.

[0184] The control unit can control the four-way valve 505 so that the heated air discharged from the vortex tube 502 is discharged to the first switching flow path 511, and the cooled air is discharged to the second switching flow path 521 (first switching mode).

[0185] The heated air discharged to the first switching flow path 511 can be supplied to the first heat exchanger 510. The first heat exchanger 510 allows the cooling water discharged from the water supply tank 13 and the heated air to exchange heat. The heated air that has undergone heat exchange can flow into the main supply flow path 202 through the first supply flow path 512 and be supplied to the burner 120. The cooled air that has undergone heat exchange supplied to the burner 120 can be used for combustion.

[0186] Cooling water stored in water supply tank 13 can be discharged from water supply tank 13 by the operation of cooling water pump 43. The cooling water discharged from water supply tank 13 is preheated by exchanging heat with heated air while passing through the first heat exchanger 510, and can then be supplied to reformer gas heat exchanger 21 through cooling water flow path 304. The cooling water supplied to reformer gas heat exchanger 21 can be supplied to fuel cell stacks 20a and 20b through fuel cell stack cooling water supply flow path 305. The cooling water supplied to fuel cell stacks 20a and 20b preheats fuel cell stacks 20a and 20b and is discharged to cooling water recovery flow path 307, and can then be recycled back to water supply tank 13.

[0187] Therefore, the cooling water discharged from the water supply tank 13 is preheated by exchanging heat with heated air in the first heat exchanger 510, and then supplied to the fuel cell stacks 20a and 20b. Thus, the preheated cooling water transfers heat to the fuel cell stacks 20a and 20b, which can quickly preheat the fuel cell stacks 20a and 20b to a temperature suitable for power generation.

[0188] The cooling air discharged to the second switching flow path 521 can be supplied to the second heat exchanger 520. The second heat exchanger 520 allows the reformed gas discharged from the reformer 140 to exchange heat with the cooling air. The cooled air that has undergone heat exchange can flow into the main supply flow path 202 through the second supply flow path 522 and be supplied to the burner 120. The cooled air that has undergone heat exchange supplied to the burner 120 can be used for combustion.

[0189] The control unit can control the reforming gas valve 33 to close and the reforming gas bypass valve 34 to open, so that the reforming gas generated and discharged in the reformer 140 is supplied to the burner 120.

[0190] The reformed gas generated and discharged in reformer 140 is cooled by exchanging heat with cooling air while passing through the second heat exchanger 520, and can then be supplied to burner 120 through reformed gas flow path 104 and reformed gas bypass flow path 105. The reformed gas supplied to burner 120 can be used for combustion.

[0191] Therefore, the reformed gas generated and discharged in the reformer 140 is cooled by exchanging heat with cooling air in the second heat exchanger 520 and then supplied to the burner 120. The reformed gas with increased density is supplied to the burner 120, thereby improving the combustion efficiency of the burner 120.

[0192] In the reforming operation mode, the control unit can determine whether the concentration value received from the concentration measurement sensor 534, which senses the concentration of carbon monoxide in the reforming gas generated in the reformer 140, has reached the set concentration value (S4).

[0193] At this time, the set concentration value refers to the carbon monoxide concentration that is suitable for inducing electrochemical reactions when the reforming gas is supplied to the fuel cells 20a and 20b, and can be a value pre-stored in the memory of the control unit.

[0194] If the concentration of carbon monoxide in the reforming gas generated in the reformer 140 is below a set concentration value, a power generation operation mode can be executed. In the power generation operation mode, the reforming gas after heat exchange with cooling air and the cooling water after heat exchange with heating air are heat exchanged and then supplied to the fuel cell stacks 20a and 20b. External air is supplied to the fuel cell stacks 20a and 20b by operating the fuel cell stack blower 72 to generate electrical energy (S5).

[0195] In the power generation operation mode, the positions or whether the three-way valve 500, four-way valve 505, first bypass valve, and second bypass valve are the same as in the reforming operation mode.

[0196] The control unit can control the reforming gas valve 33 to open and the reforming gas bypass valve 34 to close, so that the reforming gas generated and discharged in the reformer 140 is supplied to the fuel cell stacks 20a and 20b.

[0197] The reformed gas generated and discharged in the reformer 140 is cooled by exchanging heat with cooling air while passing through the second heat exchanger 520, and can then be supplied to the reformed gas heat exchanger 21 through the reformed gas flow path 104.

[0198] By operating the cooling water pump 43, the cooling water stored in the water supply tank 13 can be discharged from the water supply tank 13. The cooling water discharged from the water supply tank 13 is preheated by exchanging heat with the heated air while passing through the first heat exchanger 510, and can then be supplied to the reforming gas heat exchanger 21 through the cooling water flow path 304.

[0199] The reforming gas heat exchanger 21 allows the received cooling water and reforming gas to exchange heat. The reforming gas, after heat exchange with the cooling water, can be supplied to fuel cells 20a and 20b through fuel cell gas supply path 106. The cooling water, after heat exchange with the reforming gas, can be supplied to fuel cells 20a and 20b through fuel cell cooling water supply path 305.

[0200] Therefore, since the cooling water, which is preheated while passing through the first heat exchanger 510, is further preheated by the reformed gas in the reformed gas heat exchanger 21 and then supplied to the fuel cell stacks 20a and 20b, the preheated cooling water transfers heat to the fuel cell stacks 20a and 20b, thereby enabling the fuel cell stacks 20a and 20b to be preheated to a temperature suitable for power generation more quickly.

[0201] Therefore, since the reformed gas, which is cooled while passing through the second heat exchanger 520, is further cooled by cooling water in the reformed gas heat exchanger 21 and then supplied to the fuel cell stacks 20a and 20b, the reformed gas with increased density is supplied to the fuel cell stacks, thereby significantly improving the power generation efficiency of the fuel cell stacks 20a and 20b.

[0202] The control unit can operate the fuel cell blower 72 and open the fuel cell internal valve 36, thereby supplying external air to the fuel cell stacks 20a and 20b. Air drawn into the fuel cell blower 72 through the second external air inflow path can be supplied to the humidification unit 23 through the fuel cell side air inflow path 204. Air that has obtained moisture in the humidification unit 23 can be supplied to the fuel cell stacks 20a and 20b through the fuel cell side air supply path 205. An air flow meter 53 disposed in the fuel cell side air inflow path 204 can sense the flow rate of the air supplied to the fuel cell stacks 20a and 20b.

[0203] The control unit can discharge air from the fuel cells 20a and 20b to the outside by opening the external valve 37. The air supplied to the fuel cells 20a and 20b can be discharged to the humidification device 23 through the fuel cell side air discharge path 211 after undergoing an electrochemical reaction with the reformed gas. The moisture contained in the discharged air can be absorbed in the humidification device 23.

[0204] The air that has absorbed moisture can be supplied to the fourth heat exchanger 25 through air exhaust path 212. The air that has passed through the fourth heat exchanger 25 can be supplied to the exhaust gas discharge path 210 through exhaust path 213. The air supplied to the exhaust gas discharge path 210 can be supplied to the third heat exchanger 26 together with the exhaust gas. The air that has passed through the third heat exchanger 26 can be discharged to the outside together with the exhaust gas through exhaust path 213.

[0205] The descriptions of the third heat exchanger, the fourth heat exchanger, and the air moisture removal device 64 are the same as those described above, so their descriptions are omitted.

[0206] Fuel cells 20a and 20b can generate electrical energy by causing an electrochemical reaction between the received reformed gas and air. Since the electrochemical reaction is accompanied by the generation of heat and moisture, the heat and water generated as a result of the electrochemical reaction can be discharged through the cooling water supplied to fuel cells 20a and 20b, and the generated water vapor can be discharged together with the air discharged from fuel cells 20a and 20b.

[0207] In the power generation operation mode, the control unit can determine whether the temperature value received by the first temperature sensor 530, which senses the temperature Tw of the cooling water discharged from the fuel cell stacks 20a and 20b, is above the set cooling water temperature value T1 (S6).

[0208] At this time, the set cooling water temperature value T1 refers to the temperature at which the fuel cells 20a and 20b receive reformed gas and air and are effective in causing electrochemical reactions. It can be a value pre-stored in the memory of the control unit.

[0209] In the power generation operation mode, if the temperature Tw of the cooling water discharged from the fuel cell stacks 20a and 20b is less than the set cooling water temperature value T1, the control unit can control the supply of cooling air discharged from the vortex tube 502 to the burner 120 without exchanging heat with the reformed gas generated and discharged in the reformer 140 (S61). This operation mode of the fuel cell device 1 can be named the cooling water supplementary preheating mode (see reference). Figure 5 ).

[0210] The control unit can control the three-way valve 500 to supply air from the burner blower 71 to the vortex tube 502. For example, the three-way valve 500 can be switched to the vortex tube 502 side or kept switched to the duct side. The air supplied to the three-way valve 500 can be supplied to the vortex tube 502 through the vortex supply air passage 501.

[0211] The control unit can control the four-way valve 505 so that the heated air discharged from the vortex tube 502 is discharged to the first switching flow path 511, and the cooled air is discharged to the second switching flow path 521 (the "first switching mode" mentioned above). For example, the control unit can switch the four-way valve 505 to the first switching mode or keep the four-way valve 505 switched to the first switching mode.

[0212] The control unit can control the first bypass valve 514 to close and the second bypass valve 524 to open. For example, the control unit can keep the first bypass valve 514 in the closed position. For example, the control unit can open the second bypass valve 524 or keep the second bypass valve 524 in the open position.

[0213] Since the first bypass valve 514 is closed, the heated air discharged to the first switching flow path 511 can be supplied to the first heat exchanger 510 instead of flowing to the first bypass flow path 513.

[0214] The first heat exchanger 510 allows cooling water discharged from the water supply tank 13 to exchange heat with heated air. The heated air that has undergone heat exchange can flow into the main air supply passage 202 through the first air supply passage 512 and can be supplied to the burner 120. The heated air supplied to the burner 120 can be used for combustion.

[0215] With the second bypass valve 524 open, the cooling air discharged to the second switching flow path 521 can flow into the second bypass flow path 523 and be supplied to the second supply flow path 522, instead of being supplied to the second heat exchanger 520. The cooling air supplied to the second supply flow path can flow into the main supply flow path 202 and be supplied to the burner 120. The cooling air supplied to the burner 120 can be used for combustion.

[0216] Therefore, the heated air supplied to the burner 120 is cooled by heat exchange with cooling water in the first heat exchanger 510 and then supplied to the burner 120. The cooled air supplied to the burner 120 can bypass the second heat exchanger 520 and be supplied to the burner 120 while maintaining a low temperature. Therefore, the temperature of the air supplied to the burner 120 becomes lower and the density of the air increases, thereby improving the combustion efficiency of the burner 120.

[0217] By operating the cooling water pump 43, the cooling water stored in the water supply tank 13 can be discharged from the water supply tank 13. The cooling water discharged from the water supply tank 13 is preheated by exchanging heat with the heated air while passing through the first heat exchanger 510, and can then be supplied to the reforming gas heat exchanger 21 through the cooling water flow path 304.

[0218] The reformed gas generated and discharged in the reformer 140 can be supplied to the reformed gas heat exchanger 21 through the reformed gas flow path 104. At this time, since the cooling air discharged from the vortex tube 502 bypasses the second heat exchanger 520 and is not supplied to the second heat exchanger 520, even if the reformed gas passes through the second heat exchanger 520, it can pass through the second heat exchanger 520 at a high temperature without having its heat carried away by the cooling air.

[0219] The reforming gas heat exchanger 21 allows the received cooling water and reforming gas to exchange heat. The reforming gas supplied to the reforming gas heat exchanger 21, which has not had its heat carried away by the cooling air in the second heat exchanger 520, transfers heat to the cooling water to further preheat the cooling water, and can then be supplied to the fuel cell stacks 20a and 20b through the fuel cell stack gas supply path 106.

[0220] Cooling water passing through reforming gas heat exchanger 21 can be supplied to fuel cells 20a and 20b via fuel cell cooling water supply path 305. The cooling water supplied to fuel cells 20a and 20b preheats fuel cells 20a and 20b and is discharged to cooling water recovery path 307, where it can be recycled back to water supply tank 13.

[0221] Therefore, when the reformed gas discharged from the reformer 140 is supplied to the reformed gas heat exchanger 21 through the second heat exchanger 520, the cooling air is bypassed by the second heat exchanger 520 to prevent the reformed gas from losing heat in the second heat exchanger 520. This ensures that the gas is supplied to the reformed gas heat exchanger 21 at a high temperature and exchanges heat with the cooling water. As a result, the cooling water passing through the reformed gas heat exchanger 21 can be effectively preheated, thereby enabling the fuel cell stacks 20a and 20b to be preheated to a temperature suitable for power generation more quickly.

[0222] If the temperature value received by the first temperature sensor 530 of the cooling water Tw discharged from the sensing stacks 20a and 20b during the power generation operation mode is higher than the set cooling water temperature value T1, the control unit can determine whether the difference between the received temperature value Tw and the set cooling water temperature value T1 is less than a specified difference D (S7).

[0223] At this point, the specified difference D refers to the value that defines the width of the interval between T1 and T1+D. This interval is the temperature range in which the fuel cells 20a and 20b receive reforming gas and air and are effective in causing electrochemical reactions. It can be a value pre-stored in the memory of the control unit.

[0224] If, during the power generation operation mode, the temperature difference Tw of the cooling water discharged from the stacks 20a and 20b and the set cooling water temperature value T1, Tw-T1, is greater than or equal to a predetermined difference D, the control unit can control the cooling air discharged from the vortex tube 502 to exchange heat with the cooling water discharged from the water supply tank 13, and then supply it to the burner 120, so that the heated air discharged from the vortex tube 502 is supplied to the burner 120, without exchanging heat with the reformed gas generated and discharged in the reformer 140 (S71). This operation mode of the fuel cell device 1 can be named the cooling water overheating limitation mode (see reference). Figure 6 ).

[0225] The control unit can control the three-way valve 500 to supply air from the burner blower 71 to the vortex tube 502. For example, the three-way valve 500 can be switched to the vortex tube 502 side or kept switched to the duct side. The air supplied to the three-way valve 500 can be supplied to the vortex tube 502 through the vortex supply air passage 501.

[0226] The control unit can control the four-way valve 505 so that the heated air discharged from the vortex tube 502 is discharged to the second switching flow path 521, and the cooled air is discharged to the first switching flow path 511 (the "second switching mode" mentioned above). For example, the control unit can switch the four-way valve 505 to the second switching mode, or it can maintain the position of the four-way valve 505 switched to the second switching mode.

[0227] The control unit can control the first bypass valve 514 to close and the second bypass valve 524 to open. For example, the control unit can keep the first bypass valve 514 in the closed position. For example, the control unit can open the second bypass valve 524 or keep the second bypass valve 524 in the open position.

[0228] Since the first bypass valve 514 is closed, the cooling air discharged to the first switching flow path 511 can be supplied to the first heat exchanger 510 instead of flowing to the first bypass flow path 513.

[0229] The first heat exchanger 510 allows cooling water discharged from the water supply tank 13 and cooling air to exchange heat. The cooled air that has undergone heat exchange can flow into the main air supply passage 202 through the first air supply passage 512 and be supplied to the burner 120. The heated air supplied to the burner 120 that has undergone heat exchange can be used for combustion.

[0230] With the second bypass valve 524 open, the heated air discharged to the second switching flow path 521 can flow into the second bypass flow path 523 and be supplied to the second supply flow path 522, instead of being supplied to the second heat exchanger 520. The heated air supplied to the second supply flow path can flow into the main supply flow path 202 and be supplied to the burner 120. The heated air supplied to the burner 120 can be used for combustion.

[0231] By operating the cooling water pump 43, the cooling water stored in the water supply tank 13 can be discharged from the water supply tank 13. The cooling water discharged from the water supply tank 13 is cooled by exchanging heat with the cooling air while passing through the first heat exchanger 510, and can then be supplied to the reforming gas heat exchanger 21 through the cooling water flow path 304.

[0232] The reformed gas generated and discharged in the reformer 140 can be supplied to the reformed gas heat exchanger 21 through the reformed gas flow path 104. At this time, by causing the heated air discharged from the vortex tube 502 to bypass the second heat exchanger 520 and not be supplied to the second heat exchanger 520, even if the reformed gas passes through the second heat exchanger 520, it can pass through the second heat exchanger 520 without exchanging heat with the heated air.

[0233] The reforming gas heat exchanger 21 allows the received cooling water and reforming gas to exchange heat. The reforming gas supplied to the reforming gas heat exchanger 21 transfers heat to the cooling water to preheat the cooling water, and can then be supplied to the fuel cell stacks 20a and 20b through the fuel cell stack gas supply path 106.

[0234] Cooling water passing through reforming gas heat exchanger 21 can be supplied to fuel cells 20a and 20b via fuel cell cooling water supply path 305. The cooling water supplied to fuel cells 20a and 20b absorbs heat from fuel cells 20a and 20b and is discharged to cooling water recovery path 307, where it can be recycled back to water supply tank 13.

[0235] Therefore, the cooling water is cooled by exchanging heat with the cooling air in the first heat exchanger 510 and then supplied to the fuel cells 20a and 20b, thereby effectively absorbing the heat generated by the electrochemical reaction of the fuel cells 20a and 20b, and keeping the cooling water at an appropriate temperature without being overheated.

[0236] If, during the power generation operation mode, the temperature Tw of the cooling water discharged from the fuel cell stacks 20a and 20b is above the set cooling water temperature value T1, and the difference between the cooling water temperature Tw and the set cooling water temperature value Tw-T1 is less than a specified difference D, then the control unit can control the supply of heated air discharged from the vortex tube 502 to the burner 120 without heat exchange with the cooling water discharged from the water supply tank 13. Instead, the cooling air discharged from the vortex tube 502 exchanges heat with the reformed gas generated and discharged in the reformer 140 before being supplied to the burner 120 (S8). This operation mode of the fuel cell device 1 can be named the cooling water temperature stabilization and reformed gas cooling mode (see reference). Figure 7 ).

[0237] The control unit can control the three-way valve 500 to supply air from the burner blower 71 to the vortex tube 502. For example, the three-way valve 500 can be switched to the vortex tube 502 side or kept switched to the duct side. The air supplied to the three-way valve 500 can be supplied to the vortex tube 502 through the vortex supply air passage 501.

[0238] The control unit can control the four-way valve 505 so that the heated air discharged from the vortex tube 502 is discharged to the first switching flow path 511, and the cooled air is discharged to the second switching flow path 521 (the "first switching mode" mentioned above). For example, the control unit can switch the four-way valve 505 to the first switching mode or keep the four-way valve 505 switched to the first switching mode.

[0239] The control unit can control the first bypass valve 514 to open and the second bypass valve 524 to close. For example, the control unit can open the closed first bypass valve 514. For example, the control unit can close the second bypass valve 524 or keep the second bypass valve 524 in the closed position.

[0240] With the first bypass valve 514 open, the heated air discharged to the first switching flow path 511 can be supplied to the first supply flow path 512 via the first bypass flow path 513, instead of being supplied to the first heat exchanger 510. The heated air supplied to the first supply flow path 512 can flow into the main supply flow path 202 and be supplied to the burner 120. The heated air supplied to the burner 120 can be used for combustion.

[0241] Because the second bypass valve 524 is closed, the cooling air discharged to the second switching flow path 521 can be supplied to the second heat exchanger 520 instead of flowing to the second bypass flow path 523.

[0242] The second heat exchanger 520 allows the reformed gas discharged from the reformer 140 to exchange heat with the cooling air. The cooled air that has undergone heat exchange can flow into the main supply air passage 202 through the second supply air passage 522 and be supplied to the burner 120. The cooled air that has undergone heat exchange supplied to the burner 120 can be used for combustion.

[0243] By operating the cooling water pump 43, the cooling water stored in the water supply tank 13 can be discharged from the water supply tank 13. At this time, the heated air discharged from the vortex tube 502 bypasses the first heat exchanger 510 and is not supplied to the first heat exchanger 510, so that even if the cooling water passes through the first heat exchanger 510, it can pass through the first heat exchanger 510 without exchanging heat with the heated air. The cooling water that has passed through the first heat exchanger 510 can be supplied to the reforming gas heat exchanger 21 via the cooling water flow path 304.

[0244] The reformed gas generated and discharged in the reformer 140 is cooled by exchanging heat with cooling air while passing through the second heat exchanger 520, and can then be supplied to the reformed gas heat exchanger 21 through the reformed gas flow path 104.

[0245] The reforming gas heat exchanger 21 allows the received cooling water and reforming gas to exchange heat. The reforming gas supplied to the reforming gas heat exchanger 21 transfers heat to the cooling water to preheat the cooling water, and can then be supplied to the fuel cell stacks 20a and 20b through the fuel cell stack gas supply path 106.

[0246] Cooling water passing through reforming gas heat exchanger 21 can be supplied to fuel cells 20a and 20b via fuel cell cooling water supply path 305. The cooling water supplied to fuel cells 20a and 20b absorbs heat from fuel cells 20a and 20b and is discharged to cooling water recovery path 307, where it can be recycled back to water supply tank 13.

[0247] Therefore, the reformed gas is cooled for the first time by exchanging heat with cooling air in the second heat exchanger 520, and is further cooled by exchanging heat with cooling water in the reformed gas heat exchanger 21, and then supplied to the fuel cell stacks 20a and 20b. Thus, the reformed gas with increased density is supplied to the fuel cell stacks 20a and 20b, thereby improving the power generation efficiency of the fuel cell stacks 20a and 20b.

[0248] Therefore, by opening the first bypass valve 514 to prevent heated air from being supplied to the first heat exchanger 510, the cooling water passing through the first heat exchanger 510 is prevented from exchanging heat with the heated air, thereby maintaining the temperature of the cooling water.

[0249] In the cooling water temperature stabilization and reforming gas cooling mode, the control unit can determine whether the temperature value received by the second temperature sensor 531, which senses the temperature Tg of the reforming gas supplied to the fuel cell stacks 20a and 20b, is below the set reforming gas temperature value T2 (S9).

[0250] At this time, the reforming gas temperature value T2 refers to the maximum value among the reforming gas temperature values ​​that are effective in forming the reforming gas density in terms of electrochemical reaction in charge of the fuel cell stacks 20a and 20b, and can be a value pre-stored in the memory of the control unit.

[0251] If the temperature Tg of the reforming gas supplied to the fuel cell stacks 20a and 20b is below the set reforming gas temperature value T2, the control unit can control the supply of air from the burner blower 71 to the burner 120 (S10). This operating mode of the fuel cell device 1 can be named the normal operating mode (see reference). Figure 8 ).

[0252] The control unit can control the three-way valve 500 to supply air from the burner blower 71 to the burner 120. For example, the three-way valve 500 can be switched to the burner 120 side. The air supplied to the three-way valve 500 can be supplied to the burner 120 through the main air supply path 202.

[0253] The control unit can control the first bypass valve 514 and the second bypass valve 524 to close. For example, the control unit can close the open first bypass valve 514. For example, the control unit can keep the second bypass valve 524 in the closed position.

[0254] By operating the cooling water pump 43, the cooling water stored in the water supply tank 13 can be discharged from the water supply tank 13. At this time, the air discharged from the burner blower 71 is supplied to the burner 120 and not to the vortex tube 502, so that the cooling water can pass through the first heat exchanger 510 without additional heat exchange. The cooling water that has passed through the first heat exchanger 510 can be supplied to the reforming gas heat exchanger 21 via the cooling water flow path 304.

[0255] Since the air discharged from the burner blower 71 is supplied to the burner 120 and not to the vortex tube 502, the reformed gas generated and discharged in the reformer 140 can pass through the second heat exchanger 520 without additional heat exchange. The reformed gas passing through the second heat exchanger 520 can be supplied to the reformed gas heat exchanger 21 via the reformed gas flow path 104.

[0256] The reforming gas heat exchanger 21 allows the received cooling water and reforming gas to exchange heat. The reforming gas supplied to the reforming gas heat exchanger 21 transfers heat to the cooling water to preheat the cooling water, and can then be supplied to the fuel cell stacks 20a and 20b through the fuel cell stack gas supply path 106.

[0257] Cooling water passing through reforming gas heat exchanger 21 can be supplied to fuel cells 20a and 20b via fuel cell cooling water supply path 305. The cooling water supplied to fuel cells 20a and 20b absorbs heat from fuel cells 20a and 20b and is discharged to cooling water recovery path 307, where it can be recycled back to water supply tank 13.

[0258] Therefore, unnecessary heat exchange between the cooling water and reforming gas in the first and second heat exchangers is prevented from reaching temperatures suitable for electrochemical reactions in fuel cells 20a and 20b, and the temperatures of the cooling water and reforming gas are maintained, thereby enabling the high power generation efficiency of fuel cells 20a and 20b to be maintained.

[0259] On the other hand, the control unit measures the time Tn when entering the normal operation mode and can store it in the memory.

[0260] In normal operation mode, the control unit measures the current time Tn+1 and can calculate the elapsed time (Tn+1-Tn) since entering normal operation mode. The control unit can determine whether the elapsed time (Tn+1-Tn) since entering normal operation mode is greater than the control cycle time C (S11).

[0261] If the time elapsed after entering the normal operating mode (Tn+1-Tn) is greater than the control cycle time C, the control unit can return to step S6 and start temperature control of cooling water and reforming gas.

[0262] At this time, the control cycle time C refers to the cycle time for controlling the temperature of cooling water and reforming gas, which can be a value pre-stored in the memory of the control unit.

[0263] The accompanying drawings are only for the purpose of helping to understand the embodiments disclosed in this specification. The technical ideas disclosed in this specification are not limited to the drawings and should be understood to include all changes, equivalents and substitutions included in the ideas and technical scope of this specification.

[0264] Similarly, the actions are described in a specific order in the accompanying drawings, but this should not be construed as meaning that the actions must be performed in that specific order or sequentially to obtain the preferred result, or that all of the actions shown must be performed. In certain situations, multitasking and parallel processing may be advantageous.

[0265] For example, in this embodiment, steps S1 to S11 are listed in chronological order, but this is only to help understand the embodiments of the present invention. The present invention is not limited to this order in the process of performing steps S1 to S11.

[0266] Furthermore, the preferred embodiments of the present invention have been shown and described above, but the present invention is not limited to the specific embodiments described above. Obviously, those skilled in the art can make various modifications and implementations without departing from the spirit of the present invention as claimed in the claims. Such modified embodiments should not be understood separately from the technical concept or prospect of the present invention.

Claims

1. A fuel cell device, wherein, include: A fuel cell stack generates electrical energy by causing an electrochemical reaction between hydrogen and oxygen; A reformer generates reformed gas and supplies it to the fuel cell stack; The burner heats the reformer; A water supply tank stores cooling water to be supplied to the fuel cell stack; The burner blower draws in and delivers outside air; The main air supply path supplies air from the burner blower to the burner; The vortex tube converts the air delivered from the burner blower into heated air and cooling air; The three-way valve selectively supplies air from the burner blower to the main air supply path or the vortex tube; The four-way valve switches the heated air and the cooled air discharged from the vortex tube to be discharged through flow paths that are different from each other, namely the first switching flow path and the second switching flow path. The first heat exchanger allows cooling water discharged from the water supply tank and air discharged from the first switching flow path to exchange heat. The cooling water flow path supplies cooling water that has passed through the first heat exchanger to the fuel cell stack; The first air supply path supplies air that has passed through the first heat exchanger to the burner; The second heat exchanger allows the reformed gas discharged from the reformer to exchange heat with the air discharged from the second switching flow path. The reformed gas flow path supplies the reformed gas, which has passed through the second heat exchanger, to the fuel cell stack; as well as The second air supply path supplies the air that has passed through the second heat exchanger to the burner.

2. The fuel cell device according to claim 1, wherein, Also includes: The hot air supply path supplies the heated air discharged from the vortex tube to the four-way valve; as well as The cold air supply path supplies the cooling air discharged from the vortex tube to the four-way valve.

3. The fuel cell device according to claim 1, wherein, include: The first switching flow path connects the four-way valve and the first heat exchanger. The second switching flow path connects the four-way valve and the second heat exchanger.

4. The fuel cell device according to claim 3, wherein, Also includes: The first bypass flow path branches off from the first switching flow path and merges into the first supply flow path; A first bypass valve is configured in the first bypass flow path and is opened to allow air passing through the first switching flow path to bypass the first heat exchanger. The second bypass flow path branches off from the second switching flow path and merges into the second supply flow path; and A second bypass valve, configured in the second bypass flow path, is opened to allow air passing through the second switching flow path to bypass the second heat exchanger.

5. The fuel cell device according to claim 1, wherein, One end of the first air supply path is connected to the first heat exchanger, and the other end is merged into the main air supply path. One end of the second air supply path is connected to the second heat exchanger, and the other end is merged into the main air supply path.

6. The fuel cell device according to claim 1, wherein, It also includes a cooling water pump that supplies water stored in the water tank to the fuel cell stack.

7. The fuel cell device according to claim 1, wherein, It also includes a reforming gas heat exchanger that allows cooling water flowing through the cooling water path and reforming gas flowing through the reforming gas path to exchange heat.

8. The fuel cell device according to claim 1, wherein, Also includes: A reforming gas bypass flow path branches off from the reforming gas flow path and connects to the burner; A reforming gas bypass valve is configured in the reforming gas bypass flow path; as well as A reforming gas valve is located downstream of the branch of the reforming gas bypass flow path in the reforming gas flow path.

9. The fuel cell device according to claim 1, wherein, Also includes: The fuel cell stack blower draws in outside air and supplies it to the fuel cell stack. A fuel cell stack air supply path connects the fuel cell stack blower and the fuel cell stack. The fuel cell stack exhaust path connects the fuel cell stack to the outside. An internal valve of the fuel cell stack is configured in the fuel cell stack gas supply path and can be opened or closed; as well as An external valve for the fuel cell stack is configured in the fuel cell stack exhaust flow path and can be opened or closed.

10. The fuel cell device according to claim 1, wherein, It also includes a control unit that, if the fuel cell device starts operating, controls the three-way valve to supply air from the burner blower to the main air supply path.

11. The fuel cell device according to claim 1, wherein, It also includes a control unit. If the internal temperature of the reformer reaches the set reformer temperature value, the control unit controls the three-way valve to supply air from the burner blower to the vortex tube, and controls the four-way valve to discharge the heated air from the vortex tube to the first switching flow path and the cooled air to the second switching flow path.

12. The fuel cell device according to claim 4, wherein, Also includes: The cooling water recovery path supplies cooling water discharged from the fuel cell stack to the water supply tank; A first temperature sensor senses the temperature of the cooling water discharged from the fuel cell stack; as well as A second temperature sensor senses the temperature of the reforming gas supplied to the fuel cell stack.

13. The fuel cell device according to claim 12, wherein, It also includes a control unit. If the temperature of the cooling water sensed by the first temperature sensor is less than the set cooling water temperature value, the control unit controls the three-way valve to supply air from the burner blower to the vortex tube, and controls the four-way valve to discharge the heated air from the vortex tube to the first switching flow path and the cooled air to the second switching flow path, and controls the first bypass valve to close and the second bypass valve to open.

14. The fuel cell device according to claim 12, wherein, It also includes a control unit. If the difference between the temperature of the cooling water sensed by the first temperature sensor and the set cooling water temperature value is greater than a specified difference, the control unit controls the three-way valve to supply air from the burner blower to the vortex tube, and controls the four-way valve to discharge the heated air from the vortex tube to the second switching flow path, the cooled air to the first switching flow path, and controls the first bypass valve to close and the second bypass valve to open.

15. The fuel cell device according to claim 12, wherein, It also includes a control unit. If the temperature of the cooling water sensed by the first temperature sensor is above a set cooling water temperature value and the difference between the set cooling water temperature value and the set cooling water temperature value is less than a predetermined difference, the control unit controls the three-way valve to supply air from the burner blower to the vortex tube, and controls the four-way valve to discharge the heated air from the vortex tube to the first switching flow path and the cooled air to the second switching flow path, and controls the first bypass valve to open and the second bypass valve to close.

16. The fuel cell device according to claim 15, wherein, If the temperature of the reformed gas sensed by the second temperature sensor is below the set reformed gas temperature value, the control unit controls the three-way valve to supply air from the burner blower to the burner, and controls the first bypass valve and the second bypass valve to close.

17. A method for controlling a fuel cell device, the fuel cell device comprising a fuel cell stack that generates electrical energy by causing an electrochemical reaction between hydrogen and oxygen, and a reformer that generates reforming gas and supplies it to the fuel cell stack, wherein, The control method includes: The steps of executing the preheating operation mode are as follows: in the preheating operation mode, the burner blower draws in and discharges external air, supplies the air discharged from the burner blower to the burner, and supplies fuel to the burner, and preheats the reformer by operating the burner; If the internal temperature of the reformer reaches the set reformer temperature value, the reforming operation mode is executed. In this mode, air discharged from the burner blower is supplied to the vortex tube; cooling water discharged from the water supply tank is supplied to the fuel cell stack after heat exchange with heated air discharged from the vortex tube; reformed gas generated and discharged from the reformer is supplied to the burner after heat exchange with cooled air discharged from the vortex tube; and the heated air and cooled air after heat exchange are supplied to the burner. If the concentration of carbon monoxide in the reforming gas generated in the reformer is below a set concentration value, the power generation operation mode is executed. In the power generation operation mode, the reforming gas, after heat exchange with the cooling air, is then supplied to the fuel cell stack after heat exchange with the cooling water, which has exchanged heat with the heating air. External air is supplied to the fuel cell stack by operating the fuel cell stack blower to generate electricity.

18. The control method for a fuel cell device according to claim 17, wherein, In the step of executing the power generation operation mode, if the temperature of the cooling water discharged from the stack is lower than the set cooling water temperature value, the cooling air discharged from the vortex tube is controlled to be supplied to the burner, instead of exchanging heat with the reforming gas generated and discharged in the reformer.

19. The control method for a fuel cell device according to claim 17, wherein, In the step of executing the power generation operation mode, if the temperature difference between the cooling water discharged from the stack and the set cooling water temperature value is greater than a specified difference, then the cooling air discharged from the vortex tube is controlled to be supplied to the burner after heat exchange with the cooling water discharged from the water supply tank, and the heating air discharged from the vortex tube is supplied to the burner without heat exchange with the reforming gas generated and discharged in the reformer.

20. The control method for a fuel cell device according to claim 17, wherein, In the step of executing the power generation operation mode, if the temperature of the cooling water discharged from the stack is above the set cooling water temperature value and the difference between the set cooling water temperature value and the set cooling water temperature value is less than a specified difference, then the heated air discharged from the vortex tube is controlled to be supplied to the burner without exchanging heat with the cooling water discharged from the water supply tank. The cooling air discharged from the vortex tube is supplied to the burner after exchanging heat with the reformed gas generated and discharged in the reformer.

21. The control method for a fuel cell device according to claim 20, wherein, If the temperature of the reforming gas supplied to the fuel cell stack is below a set reforming gas temperature value, then the air discharged from the burner blower is controlled to be supplied to the burner.

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