fuel cell device

Abstract

To provide a fuel cell device with which it is possible to efficiently drain water in a circulation passage.SOLUTION: Included in a circulation passage (first heating medium circulation line 30) are a drain passage 25 that branches from between a thermal storage tank 3 and a radiator 50 and drains a heating medium in the circulation passage, and a holding unit 60 that holds a first passage 31 that constitutes a range of the circulation passage from the thermal storage tank 3 to the branch point of the drain passage 25. The holding unit 60 includes a first restriction unit 61 that restricts the upstream side height of the first passage 31 to a first height H1 or below, and a second restriction unit 62 that restricts the downstream-side height of the first passage 31 to a second height H2 or below (H1>H2). The provision of the first and second restriction units 61, 62 causes a difference in height to the first passage 31, and the difference in height enables the heating medium in the thermal storage tank 3 to be discharged, making it possible to efficiently drain.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fuel cell device. [Background technology]

[0002] Fuel cell devices are known that generate electricity using a hydrogen-containing fuel gas and an oxygen-containing gas (air) and supply the electricity to an external device. Such fuel cell devices are equipped with a heat storage tank that stores a heat medium, and the waste heat generated by the power generation of the fuel cell is recovered as a heat medium and stored in the heat storage tank, and the heat medium is used for hot water supply, heating, etc.

[0003] The fuel cell device has a circulation flow path through which the above-mentioned heat medium circulates, and on this circulation flow path, there are provided a heat exchanger that exchanges heat between the exhaust heat of the fuel cell and the heat medium, a circulation pump that circulates the heat medium, and a radiator that cools the high-temperature heat medium discharged from the heat storage tank (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-205631 Summary of the Invention [Problem to be solved by the invention]

[0005] Fuel cell devices store water necessary for power generation inside the device. Therefore, when the operation or operation of the fuel cell device is stopped for an extended period of time, the water stored inside the device must be drained to prevent damage due to freezing of the water. A drainage flow path for draining water is connected to the circulation flow path, and a structure that can perform this water drainage efficiently is desired.

[0006] SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an object to provide a fuel cell device that can efficiently drain water from the heat medium in the circulation flow path. [Means for solving the problem]

[0007] The present invention relates to a fuel cell module including fuel cells that generate electricity using a fuel gas and an oxygen-containing gas; a heat exchanger that exchanges heat between the exhaust heat of the fuel cell module and a heat medium; a heat storage tank that stores the heat medium; a radiator that cools the heat medium flowing through the heat exchanger, the radiator having a radiator that performs heat exchange between the heat medium and air; a circulation flow path through which the heat medium circulates through the heat exchanger, the heat storage tank, and the radiator; a drainage flow path that branches off from the circulation flow path between the heat storage tank and the radiator and discharges the heat medium in the circulation flow path; a holding unit that holds a first flow path that constitutes a portion of the circulation flow path from the heat storage tank to a branch point of the drainage flow path, The holding portion is a fuel cell device having a first regulating portion that regulates the height of the upstream side of the first flow path to a first height or less, and a second regulating portion that regulates the height of the downstream side of the first flow path to a second height or less that is lower than the first height. [Effects of the Invention]

[0008] With the above-described configuration, the heat medium in the circulation flow path can be efficiently drained. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram of a fuel cell device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a structural diagram illustrating a portion of the first heat medium circulation line of the present embodiment. [Figure 3] FIG. 3 is a vertical cross-sectional view of a radiator portion in a first heat medium circulation line of the present embodiment. [Figure 4] FIG. 2 is a bottom perspective view of the duct of the present embodiment. [Figure 5]FIG. 4 is an enlarged view of a connection portion between a first heat medium circulation line and a drainage flow path. [Figure 6] FIG. 2 is an exploded view of the heat sink according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A preferred embodiment of the present invention will be briefly described below, showing the operation of the present invention.

[0011] The present invention provides a fuel cell device having a circulation flow path through which a heat medium circulates a heat exchanger, a heat storage tank, and a radiator, the device including: a drainage flow path that branches off from the circulation flow path between the heat storage tank and the radiator and discharges the heat medium in the circulation flow path; and a holding unit that holds a first flow path that constitutes the circulation flow path from the heat storage tank to a branch point of the drainage flow path, the holding unit having a first restriction unit that restricts the height of the upstream side of the first flow path to a first height or less, and a second restriction unit that restricts the height of the downstream side of the first flow path to a second height or less that is lower than the first height. The provision of the first restriction unit and the second restriction unit creates a height difference in the first flow path, which allows the heat medium in the heat storage tank to be discharged using this height difference, thereby enabling efficient drainage.

[0012] Furthermore, the first flow path is maintained at a downward slope by the retaining portion. By maintaining the entire first flow path at a downward slope, water retention is suppressed, and water can be reliably drained.

[0013] The holding part has a passage through which the first flow path is inserted, and the first restriction part and the second restriction part are insertion openings for the passage. When assembling the fuel cell device, the first flow path can be held at a downward slope by inserting the first flow path into the passage, which improves workability and prevents the first flow path from coming off the holding part.

[0014] The retaining portion also has a third restriction portion consisting of one or more protruding pieces between the first restriction portion and the second restriction portion. By providing the third restriction portion in this manner, it becomes easier to maintain the first flow path at a downward gradient, allowing for efficient drainage.

[0015] At least one of the protruding pieces is provided with a fixing portion for fixing the first flow path. By providing the fixing portion, the first flow path can be more reliably maintained at a downward slope, allowing for more efficient drainage.

[0016] The heat sink further includes a duct that houses the radiator and the heat dissipation fan to form an air passage, and the holding portion is formed in the duct. By adding the function of the holding portion to an existing structure, it is possible to prevent an increase in the number of parts.

[0017] The radiator is located higher than the branch point of the drainage flow path and is connected to this branch point with a joint, which ensures that water is also drained from the radiator when draining. [Example]

[0018] An embodiment of the present invention will now be described with reference to the drawings.

[0019] 1 is a system configuration diagram of a fuel cell device according to this embodiment. The fuel cell device 100 includes a fuel cell module 1, and a plurality of accessories for operating the fuel cell module 1, such as a first heat exchanger 2, a heat storage tank 3, a condensed water tank 4, a radiator 5, an air supply device 14, a fuel supply device 15, and a reforming water supply device 16, are housed in a housing 50. It is not necessary to house all of the above-mentioned devices within the housing 50; for example, the first heat exchanger 2 and the heat storage tank 3 may be provided outside the housing 50. It is also possible to omit some of the above-mentioned devices in a fuel cell device.

[0020] The fuel cell module 1 is constructed by housing, inside a box-shaped storage container 10, a fuel cell 11 that generates electricity using fuel gas and oxygen-containing gas, and a reformer 12 that generates fuel gas to be supplied to the fuel cell 11.

[0021] The configuration of the fuel cell 11 is not particularly limited, but may have, for example, a cell stack structure in which a plurality of fuel cell units are arranged. The fuel cell 11 having a cell stack structure is constructed, for example, by fixing the lower end of each fuel cell unit to a manifold using an insulating bonding material such as a glass sealant.

[0022] The reformer 12 steam reforms raw fuel gas such as natural gas or LP gas to generate fuel gas to be supplied to the fuel cell 11. The reformer 12 is connected to a fuel supply device 15 that supplies the raw fuel gas and a reforming water supply device 16 that supplies reforming water, and the raw fuel gas and the reforming water undergo a reforming reaction in the heated reformer 12 to generate fuel gas containing hydrogen.

[0023] The fuel cell 11 is supplied with fuel gas produced in the reformer 12 and air (oxygen-containing gas) introduced by the air supply device 14. As the fuel gas passes through the fuel cell, it reacts with the oxygen-containing gas to generate electricity. The fuel gas and oxygen-containing gas that are not used for power generation join together at the top of the fuel cell 11 and are burned. This combustion of the fuel gas generates high-temperature exhaust gas, which heats the reformer 12. The exhaust gas produced in this way within the fuel cell module 1 is supplied to the first heat exchanger 2.

[0024] The first heat exchanger 2 is connected to a heat storage tank 3, a heat medium pump P1, and a radiator 5 via piping, forming a first heat medium circulation line 30. A heat medium is introduced into this first heat medium circulation line 30, and in the first heat exchanger 2, heat exchange occurs between this heat medium and the exhaust gas, heating the heat medium. Water or the like can be used as the heat medium, and the heat storage tank 3 stores the heat medium whose temperature has been increased by heat exchange. The heat medium stored in the heat storage tank 3 is sent to the radiator 5 and cooled, and then exchanges heat with the exhaust gas again in the first heat exchanger 2 before returning to the heat storage tank 3. As a result, a high-temperature heat medium is stored in the heat storage tank 3 from the top, forming a temperature stratification.

[0025] The heat dissipator 5 is equipped with a radiator 50 through which the heat medium flows, and a heat dissipation fan 51 that takes in air from outside the fuel cell device 100 and blows it to the radiator 50 as cooling air, and cools the heat medium by exchanging heat between the heat medium and the air.

[0026] A drain passage 25 is connected to the first heat medium circulation line 30. In cases such as when the fuel cell device will not be operated for an extended period of time, the heat medium in the first heat medium circulation line 30 can be discharged to the outside of the housing 40 via the drain passage 25 to prevent the water inside the device from freezing. The drain passage 25 branches off from the passage connecting the heat storage tank 3 and the radiator 50. The passage connecting the heat storage tank 3 and the radiator 50 is divided at this branch point 30a into a first passage 31 that forms the heat storage tank 3 side and a second passage 32 that forms the radiator 50 side. In addition, a drain plug 25a is provided in the drain passage 25, and the heat medium is discharged from the first heat medium circulation line 30 by opening the drain plug 25a.

[0027] In addition, a condensed water tank 4 is connected to the first heat exchanger 2 via a condensed water recovery path 20. When the exhaust gas generated in the fuel cell module 1 is cooled by heat exchange, the water vapor contained in the exhaust gas is separated into water and gas, and the separated water is recovered in the condensed water tank 4 through the condensed water recovery path 20. In the condensed water tank 4, the recovered water is purified by removing impurities through an ion exchanger (not shown) or the like. The purified water is supplied to the reformer 12 by the water supply device 16 and used as reforming water. Meanwhile, the gas from which the water has been removed passes through the exhaust path 21 and is then discharged to the outside of the housing 50.

[0028] The fuel supply device 15 that supplies raw fuel to the reformer 12 is provided with accessories such as a first solenoid valve 150, a pressure sensor 151, a desulfurizer 152, a gas flow meter 153, a fuel pump 154, and a second solenoid valve 155 on a raw fuel flow path 22 that connects to a fuel supply source. The reforming water supply device 16 that supplies reforming water to the reformer 12 is provided with accessories such as a reforming water pump 160 on a reforming water flow path 23 that connects to the condensed water tank 4. The air supply device 14 that supplies oxygen-containing gas to the fuel cell module 1 is provided with accessories such as an air filter 140, an air flow meter 141, and a blower 142 on an oxygen-containing gas flow path 24. Note that the accessories listed here are merely examples, and the configuration may include other accessories.

[0029] Furthermore, the fuel cell device 100 is provided with a control device 7 that controls the operation of various devices, as well as a power supply adjustment unit (power conditioner) 8 that converts the DC power generated by the fuel cell module 1 into AC power and adjusts the amount of the converted electricity supplied to an external load.

[0030] The fuel cell device 100 may also include a second heat exchanger 6, a heat pump P2 that circulates the heat medium from the heat storage tank 3, and a second heat medium circulation line 36 that includes piping connecting these. In the second heat medium circulation line 36, tap water supplied from the outside via a supply flow path 27 is heated in the second heat exchanger 6 using the high-temperature heat medium stored in the heat storage tank 3. The heated water can be supplied via a supply flow path 28 to a reheating device such as an external water heater.

[0031] FIG. 2 is a structural diagram illustrating a portion of the first heat medium circulation line of this embodiment. The diagram shows the heat storage tank 3, the radiator 5, the flow paths (first flow path 31 and second flow path 32) of the first heat medium circulation line 30 connecting the heat storage tank 3 and the radiator 5, and the drainage flow path 25; other components are omitted. In the diagram, solid arrows indicate the heat medium circulation direction, and dashed arrows indicate the drainage direction. The first flow path 31 is connected to the bottom of the heat storage tank 3, passes under the radiator 5, and extends toward the branch point 30a on the left side of the drawing. The radiator 50 has a heat medium inlet 501 and outlet 502. The second flow path 32 extending from the branch point 30a is connected to the inlet 501. The left side of the branch point 30a is the drainage flow path 25, which is connected to the outside of the housing 40.

[0032] Heat radiator 5 has duct 52 that forms an air passage. Duct 52 has air intake 521 at one end for taking in air and air outlet 522 at the other end for discharging air, and air intake 521 and air outlet 522 are connected to the outside of housing 40. Also housed within duct 52 is radiator 50 and heat dissipation fan 51, and air from outside housing 40 is taken into duct 52 by the rotation of heat dissipation fan 51, and heat exchange occurs between the taken-in air and a heat medium circulating through radiator 50 to cool the heat medium.

[0033] 3 is a longitudinal cross-sectional view of a radiator portion of the first heat transfer medium circulation line of this embodiment. The duct 52 has a holding portion 60 that holds the first flow path 31, and this holding portion 60 defines the height of the first flow path 31. Specifically, the holding portion 60 includes a first restricting portion 61 and a second restricting portion 62 that extend downward from the bottom surface 52a of the duct 52. The first restricting portion 61 restricts the height of the upstream side of the first flow path 31 to a first height H1 or less, and the second restricting portion 62 restricts the height of the downstream side of the first flow path 31 to a second height H2 or less that is lower than the first height H1. In this way, the provision of the first restricting portion 61 and the second restricting portion 62 creates a height difference in the first flow path 31, which makes it easier for the heat transfer medium in the first flow path 31 to flow from upstream to downstream. Therefore, when draining the water, the heat medium that flows out of the heat storage tank 3 quickly passes through the first flow path 31 and flows into the drainage flow path 25, so that the water can be drained efficiently.

[0034] In this embodiment, an example is shown in which the duct 52 forms the holding portion 60 (first restricting portion 61, second restricting portion 62). However, the holding portion 60 need only define the height of the first flow path 31, and is not limited to being formed by the duct 52. For example, if there is a frame for holding the auxiliary equipment, the holding portion may be formed on this frame, or an auxiliary equipment other than the radiator 5 may serve as the holding portion.

[0035] Furthermore, with regard to the holding portion 60, the positions at which the first regulating portion 61 and the second regulating portion 62 are provided, and the first height H1 and the second height H2 can be set as appropriate, but by maintaining the entire first flow path 31 at a downward slope from upstream to downstream, water stagnation is suppressed, thereby ensuring water drainage.

[0036] A passage 64 through which the first flow path 31 is inserted is formed in the duct 52. The first restricting portion 61 and the second restricting portion 62 serve as insertion openings for inserting the first flow path 31 into this passage 64. The first flow path 31 passes under the first restricting portion 61, passes through the passage 64, and then passes under the second restricting portion 62 to exit the passage 64. In this way, when assembling the fuel cell device 100, the first flow path 31 can be held at a downward slope simply by inserting the first flow path 31 into the passage 64, which provides excellent workability. Furthermore, it is also easy to prevent the first flow path 31 from coming off the holding portion 60.

[0037] Furthermore, a third restriction portion 63 consisting of one or more protruding pieces 631 can be provided between the first restriction portion 61 and the second restriction portion 62. In this embodiment, a plurality of protruding pieces 631 protruding from the bottom surface 52a of the duct 52 are provided between the first restriction portion 61 and the second restriction portion 62, and the protruding pieces 631 are formed so that the protruding length gradually increases from the first restriction portion 61 toward the second restriction portion 62. As a result, by abutting the first flow path 31 against the third restriction portion 63, the first flow path 31 can be maintained at a downward slope, allowing for efficient drainage.

[0038] At least one of the protruding pieces 631 may be provided with a fixing portion 65 that fixes the first flow path 31. FIG. 4 is a bottom perspective view of the duct. As shown in the figure, a plurality of protruding pieces 631 extend from the bottom surface 52a of the duct 52, and fixing portions 65 are provided at two of the protruding pieces 631 to fix the first flow path 31 to the duct 52. The structure of the fixing portions 65 is not particularly limited. For example, as shown in the figure, a part such as a nylon clip may be used and attached to the bottom surface of the duct 52 with a screw, or a hook-shaped locking portion may be provided at the tip of the protruding piece 631 to lock the first flow path 31.

[0039] 5 is an enlarged view of the connection between the first heat medium circulation line and the drainage flow path. The first flow path 31 consists of a hose 70, and a branch joint 71 that branches the flow path in two directions is attached to the downstream end of the hose 70. This branch joint 71 causes the first flow path 31 to branch into a second flow path 32 and a drainage flow path 25. A radiator connection joint 72 is attached to the second flow path 32 side of the branched branch joint 71 and is connected to the inlet 501 of the radiator 50. On the other hand, a drainage hose 73 is connected to the drainage flow path 25 side of the branch joint 71, and the drainage hose 73 is connected to the outside of the housing 40.

[0040] Because the first flow path 31 passes under the radiator 50 and is maintained at a downward slope, the start point (branch point 30a) of the drainage flow path 25 is located at a position lower than the radiator 50. In other words, the second flow path 32, from which water is discharged from the radiator 50 during drainage, also has a downward slope toward the drainage flow path 25. Furthermore, because the inlet 501 of the radiator 50 and the branch point 30a are linearly connected by a joint, the water in the radiator 50 can be quickly flowed into the drainage flow path 25, allowing for efficient drainage. The branch joint 71 and the radiator connection joint 72 may be integrated.

[0041] The water discharged from the radiator 50 and the water discharged from the heat storage tank 3 join at the branch point 30a. If the draining of the heat storage tank 3 is completed before the draining of the radiator 50, air will enter the branch point 30a, preventing any more water from being drained from the radiator 50. Therefore, by considering the structure and arrangement of each part so that the draining of the radiator 50 is completed before the draining of the heat storage tank 3, it is possible to more reliably perform the draining of water. For example, the height of the radiator 50 may be adjusted, or a trap may be provided in the first flow path 31 to obstruct the flow of water from the heat storage tank 3 toward the drain flow path 25.

[0042] FIG. 6 is an exploded view of the heat sink of this embodiment. The duct 52 of the heat sink 5 has a structure that can be disassembled into three parts: a lower duct 523, a first upper duct 524, and a second upper duct 525. The lower duct 523 forms the lower half of the duct 52, has a heat dissipation fan 51 attached thereto, and has a mounting portion 523a for the radiator 50. This mounting portion 523a also serves as a holder 60 that holds the first flow path 31. The first upper duct 524 and the second upper duct 525 form the upper half of the duct 52. The first upper duct 524 covers the upper side of the radiator 50, and sandwiches and fixes the radiator 50 between the first upper duct 524 and the lower duct 523. The second upper duct 525 covers the upper side of the heat dissipation fan 51. By making the duct 52 disassembled in this way, the maintainability of the heat sink 5 can be improved.

[0043] To further improve maintainability, the first upper duct 524 and the second upper duct 525 are attached to the lower duct 52 without using screws. Specifically, the first upper duct 524 and the second upper duct 525 are fixed to the lower duct 523 by engaging locking portions 524a, 525a provided on the first upper duct 524 and the second upper duct 525 with locked portions 523b provided on the lower duct 523. Furthermore, the second upper duct 525 and the lower duct 523 have rivet fixing portions 526 that are fixed using push rivets. This improves the ease of attachment and detachment and also prevents the problem of dropping screws. [Explanation of symbols]

[0044] 1 Fuel Cell Module 2 1st heat exchanger (heat exchanger) 3. Heat storage tank 5 Heat sink 30 First heat medium circulation line (circulation flow path) 30a Junction 31 First Channel 25 Drainage channel 50 Radiator 51 Heat dissipation fan 52 Duct 60 Holding part 61 First Regulatory Department 62 Second Regulatory Department 63 Third Regulatory Department 631 Projecting piece 64 Passage 65 Fixed part 71 Branch joint (joint) 72 Radiator connection joint (joint)

Claims

1. a fuel cell module including fuel cells that generate electricity using a fuel gas and an oxygen-containing gas; a heat exchanger that exchanges heat between the exhaust heat of the fuel cell module and a heat medium; a heat storage tank that stores the heat medium; a radiator that cools the heat medium flowing through the heat exchanger, the radiator having a radiator that performs heat exchange between the heat medium and air; a circulation flow path through which the heat medium circulates through the heat exchanger, the heat storage tank, and the radiator; a drainage flow path that branches off from the circulation flow path between the heat storage tank and the radiator and discharges the heat medium in the circulation flow path; a holding unit that holds a first flow path that constitutes a portion of the circulation flow path from the heat storage tank to a branch point of the drainage flow path, The holding portion is a fuel cell device having a first regulating portion that regulates the height of the upstream side of the first flow path to a first height or less, and a second regulating portion that regulates the height of the downstream side of the first flow path to a second height or less that is lower than the first height.

2. 2. The fuel cell device according to claim 1, wherein the first flow path is maintained at a downward gradient by the holding portion.

3. the holding portion includes a passage through which the first flow path is inserted, 3. The fuel cell device according to claim 2, wherein the first restricting portion and the second restricting portion are insertion openings of the passages.

4. 4. The fuel cell device according to claim 3, wherein the holding portion has a third restriction portion formed of one or more protruding pieces between the first restriction portion and the second restriction portion.

5. 5. The fuel cell device according to claim 4, wherein at least one of the protruding pieces is provided with a fixing portion for fixing the first flow path.

6. the heat sink further includes a heat dissipation fan that generates an airflow, and a duct that houses the radiator and the heat dissipation fan and forms an air passage; 6. The fuel cell device according to claim 1, wherein the holding portion is formed in the duct.

7. 7. The fuel cell device according to claim 6, wherein the radiator is disposed at a position higher than a branch point of the drainage flow path and is connected to the branch point by a joint.

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