CN-116130706-B - Fuel cell device and control method thereof

Abstract

The fuel cell device includes a stack, a reformer, a combustor, a water supply tank, a combustor blower, a main air supply passage, a vortex tube, a three-way valve for selectively supplying air sent from the combustor blower to the main air supply passage or the vortex tube, a four-way valve for switching between a first switching passage and a second switching passage between heated air and cooling air discharged from the vortex tube, a first heat exchanger for exchanging heat between cooling water discharged from the water supply tank and air discharged from the first switching passage, a cooling water passage for supplying cooling water having passed through the first heat exchanger to the stack, a first air supply passage for supplying air having passed through the first heat exchanger to the combustor, a second heat exchanger for exchanging heat between reformed gas discharged from the reformer and air discharged from the second switching passage, a reformed gas passage for supplying reformed gas having passed through the second heat exchanger to the stack, and a second air supply passage for supplying air having passed through the second heat exchanger to the combustor.

Inventors

• ZHANG XIZHONG
• Liang Tonggen
• YU HENGXI
• Quan Zhixun

Assignees

• LG电子株式会社

Dates

Publication Date

20260512

Application Date

20221107

Priority Date

20211112

Claims (20)

1. 1. A fuel cell apparatus, comprising: a stack for generating electric energy by electrochemically reacting hydrogen and oxygen; A reformer generating a reformed gas and supplying it to the stack; A burner for heating the reformer; a water supply tank storing cooling water to be supplied to the electric pile; A burner blower for sucking and delivering outside air; A main air supply flow path for supplying air sent from the burner blower to the burner; a vortex tube for converting air sent from the burner blower into heating air and cooling air; 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 between discharging the heating air and the cooling air discharged from the vortex tube through different channels from each other; A first heat exchanger for exchanging heat between the cooling water discharged from the water supply tank and the air discharged from the first switching flow path; a cooling water flow path for supplying cooling water having passed through the first heat exchanger to the stack; A first air supply flow path for supplying air having passed through the first heat exchanger to the burner; a second heat exchanger for exchanging heat between the reformed gas discharged from the reformer and the air discharged from the second switching flow path; A reformed gas flow path for supplying the reformed gas having passed through the second heat exchanger to the electric stack, and And a second air supply flow path for supplying air having passed through the second heat exchanger to the burner.
2. 2. The fuel cell device according to claim 1, further comprising: A hot air supply flow path for supplying the heated air discharged from the vortex tube to the four-way valve, and A cool air supply flow path for supplying the cool air discharged from the vortex tube to the four-way valve.
3. 3. The fuel cell device according to claim 1, wherein comprising: 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. 4. The fuel cell device according to claim 3, further comprising: A first bypass flow path branching from the first switching flow path and merging into the first air supply flow path; a first bypass valve disposed in the first bypass passage and configured to open to bypass the air passing through the first switching passage to the first heat exchanger; A second bypass passage branched from the second switching passage and merging into the second air supply passage, and And a second bypass valve disposed in the second bypass passage and configured to open to bypass the air passing through the second switching passage to the second heat exchanger.
5. 5. The fuel cell device according to claim 1, wherein, One end of the first air supply flow path is communicated with the first heat exchanger, the other end is combined with the main air supply flow path, One end of the second air supply flow path is communicated with the second heat exchanger, and the other end of the second air supply flow path is combined with the main air supply flow path.
6. 6. The fuel cell device according to claim 1, wherein, And a cooling water pump for supplying water stored in the water supply tank to the electric pile.
7. 7. The fuel cell device according to claim 1, wherein, The apparatus further includes a reformed gas heat exchanger that exchanges heat between the cooling water passing through the cooling water passage and the reformed gas passing through the reformed gas passage.
8. 8. The fuel cell device according to claim 1, further comprising: a reformed gas bypass passage branched from the reformed gas passage and communicating with the burner; a reformed gas bypass valve disposed in the reformed gas bypass flow path, and And a reformed gas valve disposed downstream of the reformed gas bypass passage in the reformed gas passage at a position where the reformed gas bypass passage branches.
9. 9. The fuel cell device according to claim 1, further comprising: A stack blower sucking external air and supplying it to the stack; a stack air supply flow path connecting the stack blower and the stack; a stack exhaust flow path that communicates the stack with the outside; An in-stack valve disposed in the stack air supply passage and capable of opening and closing, and An off-stack valve disposed in the stack exhaust passage and capable of opening and closing.
10. 10. The fuel cell device according to claim 1, wherein, And a control unit that controls the three-way valve so that air sent from the burner blower is supplied to the main air supply flow path when the fuel cell device starts to operate.
11. 11. The fuel cell device according to claim 1, wherein, And a control unit that controls the three-way valve such that air sent from the burner blower is supplied to the vortex tube and the four-way valve such that the heated air discharged from the vortex tube is discharged to the first switching flow path and the cooled air is discharged to the second switching flow path, if the internal temperature of the reformer reaches a set reformer temperature value.
12. 12. The fuel cell device according to claim 4, further comprising: A cooling water recovery flow path for supplying cooling water discharged from the stack to the water supply tank; A first temperature sensor for sensing the temperature of the cooling water discharged from the electric pile, and And a second temperature sensor that senses a temperature of the reformed gas supplied to the electric pile.
13. 13. The fuel cell device according to claim 12, wherein, The control part controls the three-way valve such that air sent from the burner blower is supplied to the vortex tube and controls the four-way valve such that the heated air discharged from the vortex tube is discharged to the first switching flow path, the cooled air is discharged to the second switching flow path, and the first bypass valve is controlled to be closed and the second bypass valve is controlled to be opened, if the temperature of the cooling water sensed by the first temperature sensor is less than a set cooling water temperature value.
14. 14. The fuel cell device according to claim 12, wherein, And a control unit that controls the three-way valve such that air sent from the burner blower is supplied to the vortex tube and the four-way valve such that the heated air discharged from the vortex tube is discharged to the second switching flow path, the cooling air is discharged to the first switching flow path, and the first bypass valve is controlled to be closed and the second bypass valve is controlled to be opened, if a difference between the temperature of the cooling water sensed by the first temperature sensor and a set cooling water temperature value is equal to or greater than a predetermined difference.
15. 15. The fuel cell device according to claim 12, wherein, And a control unit configured to control the three-way valve such that air sent from the burner blower is supplied to the vortex tube and the four-way valve is controlled such that the heated air discharged from the vortex tube is discharged to the first switching flow path, the cooled air is discharged to the second switching flow path, and the first bypass valve is controlled to be opened and the second bypass valve is controlled to be closed, if the temperature of the cooling water sensed by the first temperature sensor is equal to or higher than a set cooling water temperature value and a difference from the set cooling water temperature value is smaller than a predetermined difference.
16. 16. The fuel cell device according to claim 15, wherein, The control portion controls the three-way valve such that air sent from the burner blower is supplied to the burner and controls the first bypass valve and the second bypass valve to be closed, if the temperature of the reformed gas sensed by the second temperature sensor is equal to or lower than a set reformed gas temperature value.
17. 17. A control method of a fuel cell apparatus including a stack that generates electric power by causing hydrogen and oxygen to electrochemically react, and a reformer that generates reformed gas and supplies it to the stack, The control method comprises the following steps: a step of executing a warm-up operation mode in which a burner blower sucks and discharges external air, supplies the air discharged from the burner blower to a burner, and supplies fuel to the burner, and warms up the reformer by operating the burner; A step of executing a reforming operation mode in which air discharged from the burner blower is supplied to a vortex tube, cooling water discharged from a water supply tank is supplied to the stack after heat exchange with heating air discharged from the vortex tube, reformed gas generated and discharged from the reformer is supplied to the burner after heat exchange with cooling air discharged from the vortex tube, and the heat exchanged heating air and cooling air are supplied to the burner, if an internal temperature of the reformer reaches a set reformer temperature value, and And a step of executing a power generation operation mode in which, when the concentration of carbon monoxide contained in the reformed gas generated in the reformer is equal to or less than a set concentration value, the reformed gas subjected to heat exchange with the cooling air is supplied to the electric pile after heat exchange with the cooling water subjected to heat exchange with the heating air, and the electric pile blower is operated to supply air outside the electric pile to generate electric energy.
18. 18. The control method of a fuel cell device according to claim 17, wherein, In the step of executing the power generating operation mode, if the temperature of the cooling water discharged from the stack is less than a set cooling water temperature value, the cooling air discharged from the vortex tube is controlled to be supplied to the burner without heat exchange with the reformed gas generated and discharged in the reformer.
19. 19. The control method of a fuel cell device according to claim 17, wherein, In the step of executing the power generation operation mode, if a difference between the temperature of the cooling water discharged from the stack and a set cooling water temperature value is equal to or greater than a predetermined difference, 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 reformed gas generated and discharged from the reformer.
20. 20. The control method of 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 equal to or higher than a set cooling water temperature value and a difference from the set cooling water temperature value is smaller than a predetermined difference, the heating air discharged from the vortex tube is controlled to be supplied to the burner without heat exchange with the cooling water discharged from the water supply tank, and the cooling air discharged from the vortex tube is supplied to the burner after heat exchange with the reformed gas generated and discharged from the reformer.

Description

Fuel cell device and control method thereof Technical Field The present invention relates to a fuel cell device and a control method thereof, and more particularly, to a fuel cell device capable of controlling the temperatures of cooling water and reformed gas by using a vortex tube. Background The fuel cell device (Fuel cell apparatus) is a power generation device that generates electric power by electrochemically reacting hydrogen contained in hydrocarbon substances such as methanol, ethanol, natural gas, and the like with oxygen. Similar to prior art 1 (korean laid-open patent publication No. 10-2012-0071888), the existing fuel cell apparatus includes a fuel processing device that reforms (reforms) a fuel containing hydrogen atoms into hydrogen gas, and a stack (stack) that generates electric power using the hydrogen gas supplied from the fuel processing device. The fuel cell device may further include a heat exchanger for cooling the stack and recovering heat, a cooling water pipe, a power conversion device for converting the generated dc power into ac power, and the like. Since oxygen must be used in the combustion of fuel gas occurring in the burner of the fuel processing apparatus or in the generation of electricity in the electric pile, the fuel cell apparatus generally includes a blower (blower) for flowing external air to the fuel processing apparatus or the electric pile, similarly to the prior art 2 (korean patent laid-open publication No. 10-1951439). In the conventional fuel cell apparatus, first, a reformer for receiving a fuel gas and generating a reformed gas necessary for power generation of a stack is heated by a burner to preheat the reformed gas to a temperature suitable for reforming, and then, in a reforming mode in which the reformed gas generated in the reformer is recirculated to the burner and reformed repeatedly until the concentration of hydrogen, carbon monoxide, and the like of the generated reformed gas reaches a concentration suitable for power generation of the stack, if the temperature condition of the reformer is reached, the reformer is operated, and then, in a power generation mode in which the reformed gas and external air are supplied to the stack and an electrochemical reaction is caused to generate electric power, the reformer is operated. In this case, the electric pile generally exhibits the best power generation efficiency at a temperature of about 75 degrees, and in the case of the conventional technique, only the reformed gas at a high temperature and the cooling water heated by heat exchange with the reformed gas are supplied to the electric pile and start to warm up the electric pile, so that there is a problem in that the power generation efficiency is lowered at the initial stage of the power generation operation due to the low temperature of the electric pile. On the other hand, with the power generating operation of the fuel cell apparatus, heat is generated in the cell stack, and this heat can reach a temperature suitable for power generation of the cell stack at the initial stage of the power generating operation, but heat radiation is required after the cell stack reaches the target temperature to prevent the cell stack from being excessively heated. In the conventional fuel cell apparatus, in a case where the power generation mode is maintained for a certain period of time and the stack reaches a target temperature, and heat generated according to the operation of the fuel cell apparatus is required to be dissipated, since a system is used in which hot water of a water supply tank for recycling heat by circulating cooling water according to the operation of the fuel cell apparatus is discharged to the outside and then cold water is supplied again from an external water supply source, there is a problem in that it is difficult to achieve precise thermal management of the fuel cell apparatus and additional operation cost due to water supply is generated. Prior art literature Patent literature Patent document 1 KR 10-2012-00711288A Patent document 2 KR10-1951439B Disclosure of Invention The purpose of the present invention is to provide a fuel cell device that improves the power generation efficiency by shortening the time for preheating a stack to a temperature suitable for power generation. Another object of the present invention is to provide a fuel cell device that can simply and effectively dissipate waste heat generated in a stack to maintain an optimal temperature. It is still another object of the present invention to provide a fuel cell apparatus that improves the combustion efficiency of a combustor or the power generation efficiency of a stack by increasing the density of reformed gas supplied to the combustor or the stack. It is still another object of the present invention to provide a fuel cell apparatus that improves the combustion efficiency of a burner by increasing the density of air supplied to the burner. It is still another object of