JP2013217509A - Cogeneration system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cogeneration system that is superior in workability of manufacturing processes and maintenance.SOLUTION: A cogeneration system includes: a power generation device 2 which generates electric power; a waste gas purification device 3 which purifies a waste gas discharged from the power generation device 2; and a heat recovery device 4 which recovers heat from the purified gas. A connection portion connecting the waste gas purification device 3 and heat recovery device 4 is inclined at a predetermined angle relative to a connection plane between the waste gas purification device 3 and power generation device 2. Consequently, screwing places of the heat recovery device 4 can be confirmed even without peeping from below the waste gas purification device 3, and thereby, the heat recovery device 4 is easily attached and detached to improve workability of manufacturing processes and maintenance.

Description

  The present invention relates to a cogeneration system that uses waste heat generated during power generation to supply electric power and heat together for efficient use of energy.

  Conventionally, a cogeneration system has been developed that uses exhaust heat from an internal combustion engine or an external combustion engine to extract power, heat, and cold to increase overall energy efficiency. This cogeneration system includes, for example, a cogeneration device composed of a heat engine such as an engine or a gas turbine and a generator, and burns fuel in the heat engine to drive the generator to generate power. The system is configured to perform heating and hot water supply using exhaust heat, and in recent years, a system using a fuel cell as a cogeneration device has been proposed.

  The fuel cell system used here performs power generation by supplying a fuel gas and an oxygen-containing gas to a cell stack, and high-temperature exhaust gas is discharged from the battery module along with power generation.

  And, downstream of the battery module, a heat recovery device for recovering heat from the high temperature exhaust gas discharged from the battery module is provided, and this heat recovery device is connected to the hot water storage tank by a heat medium circulation path, Hot water generated by heat exchange with the exhaust gas is stored in a hot water storage tank, and the exhaust gas that has passed through the heat recovery device is discharged outside the device.

  In Patent Document 1, a purification catalyst is used as an exhaust gas purification device in an exhaust path of a fuel cell system in order to purify an environmental impact component contained in the exhaust gas of the fuel cell system and safely discharge it outside the fuel cell system. The heat of the exhaust gas that has passed through the purification catalyst is stored in the hot water storage tank via the heat recovery device.

JP 2010-238446 A

  By the way, in such a cogeneration system, downsizing of the apparatus and power generation performance are regarded as the most important items. For this reason, a large number of parts and pipes are densely arranged in a narrow space, and as a result, the manufacturing process and maintenance work may be difficult.

  Specifically, in the case of the system as described above, generally, an exhaust gas purification device is disposed below the battery module, and a heat recovery device is disposed below the exhaust gas purification device. A heat recovery device is attached to the bottom with screws or bolts. In the manufacturing process of the system, it is necessary to install a heat recovery device by inserting a driver from below the exhaust gas purification device, but the workability is limited because the space for the driver to enter is limited in a narrow space where many parts and piping are densely packed. Was getting worse.

  Moreover, in order to use a cogeneration system safely, it is necessary to perform regular maintenance. For example, a purification catalyst used in an exhaust gas purification device is activated by a purification action when it reaches a certain temperature. Therefore, a heater is provided inside to raise the temperature of the purification catalyst, but the heater gradually deteriorates with use. As a result, the output may be reduced or the wire may be disconnected. Therefore, periodic maintenance work must be performed for inspection and replacement. However, in order to take out the exhaust gas purification device during maintenance, it is necessary to remove the heat recovery device connected below the exhaust gas purification device. In order to remove the heat recovery device, a screwdriver and bolts must be removed by inserting a screwdriver as if looking into the exhaust gas purification device from below. In addition, such devices are often installed along the walls of the building being used. For this reason, at least one surface of the apparatus comes into contact with the building, and the place where the maintenance work is performed is also restricted, so that workability is further deteriorated.

  The present invention is for solving the above-described problems, and an object of the present invention is to provide a cogeneration system excellent in manufacturing process and maintenance workability.

  The present invention includes a power generation device that generates power, an exhaust gas purification device that purifies exhaust gas discharged from the power generation device, and a heat recovery device that recovers heat from the exhaust gas that has passed through the exhaust gas purification device. It is a cogeneration system characterized in that the connecting portion connecting the heat recovery device has an inclination of a predetermined angle with respect to the connecting surface between the exhaust gas purification device and the power generation device.

  Further, the connecting portion may be further characterized by facing the direction in which the heat recovery apparatus is attached.

  Further, the exhaust gas purification device may be further disposed at the bottom of the power generation device, and the heat recovery device may be further disposed between the exhaust gas purification device and the heat recovery device mounting work surface.

  In addition, the exhaust gas purification device may further include a purified exhaust gas passage through which the purified exhaust gas passes, and may be further characterized in that a connection portion is provided in the purified exhaust gas passage.

  Further, the exhaust gas purifying device and the purified exhaust gas flow path may be further formed integrally.

  Further, the inclination of the connecting portion may be 45 to 90 °.

  The connecting portion may be a plate-like connecting member, and the connecting member may further have a screw hole.

  With the configuration as described above, the heat recovery device can be easily attached and detached, so that the workability of the manufacturing process and maintenance can be improved.

It is a block diagram of the cogeneration system of this invention. It is a schematic block diagram of the cogeneration system of this invention. Fig.3 (a) is sectional drawing in 1st Embodiment of the exhaust gas purification apparatus of this invention. FIG. 3B is a view showing the angle of the connecting portion in the first embodiment of the present invention. It is the schematic explaining the arrangement | positioning inside a cogeneration system of this invention, and a heat recovery apparatus attachment work surface. Fig.5 (a) is sectional drawing in 2nd Embodiment of the exhaust gas purification apparatus of this invention. FIG. 5B is a view showing the angle of the connecting portion in the second embodiment of the present invention. Fig.6 (a) is sectional drawing in 3rd Embodiment of the exhaust gas purification apparatus of this invention. FIG. 6B is a view showing the angle of the connecting portion in the third embodiment of the present invention. Fig.7 (a) is sectional drawing which shows the modification of 3rd Embodiment of the exhaust gas purification apparatus of this invention. FIG.7 (b) is the figure which showed the angle of the connection part in the modification of 3rd Embodiment of this invention. It is a figure explaining attachment of the conventional exhaust gas purification apparatus and a heat recovery device.

  An embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, a case where a fuel cell system is used as the power generation device will be described as an example. However, the power generation device is not limited to this, and a heat engine such as an engine or a gas turbine can also be used.

First embodiment

  FIG. 1 and FIG. 2 show schematic views when the fuel cell system 1 is used as a cogeneration system. A fuel cell system 1 includes a battery module 2 as a power generator for generating power, and an exhaust gas purification device that removes and purifies unburned components such as carbon monoxide, hydrogen, and methane contained in exhaust gas discharged from the battery module 2. 3. A heat recovery device 4 that recovers heat from exhaust gas that has passed through the exhaust gas purification device 3 using a heat medium, a heat medium circulation path 30, and a heat storage tank 31 that stores heat recovered by the heat recovery device 4. Yes. For example, water can be used as the heat medium. In this case, the water heated in the heat recovery device 4 can be stored in the heat storage tank 31 as hot water.

  The fuel cell system 1 includes a reforming device 5 that generates a fuel gas using a hydrogen-containing fuel, a hydrogen-containing fuel supply passage 18 that supplies the reforming device 5 with a hydrogen-containing fuel as a raw fuel, an exhaust gas passage 12, , An oxidant gas flow path 13, a reformed water supply path 17 that supplies reformed water to the reformer 5, and a cell stack that is an assembly of fuel cells that generate power using fuel gas and oxidant gas 6 and so on. In addition, FIG. 2 shows an outline and does not limit the structure, shape, and positional relationship of each component. For example, the shape of the cells constituting the cell stack 6 may be a plate shape or a cylindrical shape. The cell stack may have a shape in which a plurality of cells are connected in series, parallel, or series-parallel.

  The reformer 5 is configured by filling a reforming catalyst therein, and can generate hydrogen by a steam reforming method, a partial oxidation method, an autothermal reforming method, or a combination thereof. it can.

  As the hydrogen-containing fuel, for example, a hydrocarbon fuel can be used. As the hydrocarbon fuel, a compound containing carbon and hydrogen in the molecule (may contain other elements such as oxygen) or a mixture thereof is used. Examples of the hydrocarbon fuel include hydrocarbons, alcohols, ethers, and biofuels. As these hydrocarbon fuels, those derived from conventional fossil fuels such as petroleum and coal, those derived from synthetic fuels such as synthesis gas, and those derived from biomass can be appropriately used. Specific examples of hydrocarbons include methane, ethane, propane, butane, natural gas, LPG (liquefied petroleum gas), city gas, town gas, naphtha, kerosene, and light oil. Examples of alcohols include methanol and ethanol. Examples of ethers include dimethyl ether. Examples of biofuels include biogas, bioethanol, biodiesel, and biojet.

  As the oxidizing agent, for example, air, pure oxygen gas (which may contain impurities that are difficult to remove by a normal removal method), or oxygen-enriched air can be used.

  A fuel gas supply path 9 is provided between the reformer 5 and the cell stack 6, and the fuel gas generated by the reformer 5 passes through the fuel gas supply path 9 to each cell of the cell stack 6. It is supplied to the anode 6a. The oxidant gas is supplied to the cathode 6 c of the cell stack 6 through the oxidant gas supply path 13. The fuel gas and the oxidant gas that have not reacted in the cell stack 6 are combusted in the combustion unit 10, and the reformer 5 is heated by the heat of the exhaust gas resulting from the combustion.

  An exhaust pipe 15 is provided downstream of the exhaust gas flow path 12, and fuel gas or oxidant that has not reacted in the cell stack 6 or exhaust gas due to combustion thereof is connected downstream through the exhaust pipe 15. Into the exhaust gas purification device 3.

  2 shows an example in which the battery module 2 includes the reformer 5, the cell stack 6, and the combustion unit 10, but the configuration is not limited thereto. For example, a vaporizer for vaporizing the reforming water and a desulfurizer for removing sulfur components contained in the raw fuel may be included. Alternatively, the reformer 5 may be provided independently from the battery module 2.

  FIG. 3 shows a first embodiment of the present invention. FIG. 3A is a cross-sectional view of the exhaust gas purification device 3. The exhaust gas purification device 3 is connected to the downstream of the exhaust gas flow path 12 via the exhaust pipe 15, and removes unburned components such as carbon monoxide, hydrogen, methane and the like from the exhaust gas flowing through the exhaust gas purification device 3. The purification catalyst 20 for purifying the catalyst, the purification catalyst case 21 in which the purification catalyst 20 is accommodated, the heater 22 for heating the purification catalyst 20, the catalyst temperature detection unit 23, and the bottom plate 24 are configured.

  The fluid flowing into the exhaust gas purification device 3 from the exhaust gas passage 12 passes through the purification catalyst 20 heated to a temperature at which the purification action is activated by the heater 22, and the unburned components are purified.

  The heater 22 is a sheathed heater in which a nichrome wire is embedded inside a metal heater pipe and magnesia, which is an insulating powder, is filled, and a heater terminal 22c is provided at the end.

  As the purification catalyst 20, a generally known catalyst such as a noble metal catalyst such as platinum or palladium or a base metal catalyst such as manganese or iron is used, and unpurified catalysts such as carbon monoxide, hydrogen, and methane contained in the exhaust gas are used. By purifying and decomposing the fuel component, the exhaust gas is purified. When heated, the exhaust gas is activated and activated to efficiently decompose and decompose harmful components. Further, the shape of the purification catalyst 20 is not particularly limited, and any honeycomb type, pellet type, metal foam or the like can be used as long as it can be accommodated in the purification catalyst case 21. May be selected as appropriate.

  The catalyst temperature detection unit 23 is inserted from the bottom plate 24 so that the temperature detection point of the catalyst temperature detection unit 23 is buried in the purification catalyst 20. The temperature acquired by the catalyst temperature detector 23 is used for output control of the heater 22.

  The purification catalyst case 21 is a substantially cylindrical tubular body. The first flange 21a is formed by folding the lower end outward, and the second flange 21b for connecting to the exhaust pipe 15 is attached to the upper end. Since the exhaust gas purification device 3 is attached to the battery module 2 by screwing the second flange 21b and the exhaust pipe 15, the second flange 21b is connected to the exhaust gas purification device 3 and the battery module 2. It becomes.

  The bottom plate 24 has a cylindrical purified exhaust gas passage 26 joined thereto by welding, and a connecting member 27 for joining to the heat recovery device 4 is joined to the end of the purified exhaust gas passage 26. The exhaust gas purified in this way flows into the heat recovery device 4 through the purified exhaust gas passage 26.

  The connection member 27 has a screw hole 28 for screwing the heat recovery device 4. If the heat recovery device 4 is directly attached to the purified exhaust gas flow path 26, the exhaust gas flowing through the purified exhaust gas flow path 26 may leak from the screw hole. Then, the connection member 27 and the heat recovery device 4 are screwed to eliminate the possibility that the exhaust gas leaks from the screw hole 28. Further, since the connection member 27 is attached to the purified exhaust gas flow path 26 by welding, the exhaust gas does not leak from the joint portion between the connection member 27 and the purified exhaust gas flow path 26.

  FIG. 3B is a diagram showing the angle of the connection member 27. The connecting member 27 is attached to the purified exhaust gas flow path 26 with a predetermined angle of inclination θ with respect to the second flange 21b, which is a connection surface between the exhaust gas purifying device 3 and the battery module 2. This inclination θ is an angle at which an operator can easily attach and remove screws without looking into from the lower side when attaching and detaching the exhaust gas purification device 3 and the heat recovery device 4. A range of ° is preferable.

  The inclination θ of the connection member 27 may be changed depending on the angle at which the connection member 27 is joined to the purified exhaust gas passage 26, or may be changed depending on the shape of the purified exhaust gas passage 26. For example, in FIG. 3, the purified exhaust gas flow path 26 is configured by connecting two cylindrical pipes in a substantially L shape, but the inclination θ can be changed by changing the angle connecting the pipes.

  Here, the manufacturing process and maintenance work of the cogeneration system in the first embodiment will be described.

  FIG. 4 is a cross-sectional view showing the internal arrangement of the cogeneration system of the present invention. Generally, the cogeneration system is often provided along the wall surface of a building, and maintenance cannot be performed from the direction along the wall surface. Therefore, the direction in which the worker performs the maintenance work (black arrow) is determined in advance as the heat recovery device mounting work surface, the maintenance opening 33 is provided in the exterior 32 of the cogeneration system, and the connection member 27 is the maintenance opening 33. It is arranged so as to face. Usually, the maintenance opening 33 is closed by a door (not shown).

  In the manufacturing process of the cogeneration system, the exhaust gas purification device 3 is first attached to the bottom of the battery module 2, and then the heat recovery device 4 is attached to the exhaust gas purification device 3. Here, a conventional manufacturing process will be described with reference to FIG. In the conventional configuration, the heat recovery device 4 is attached to the bottom surface of the exhaust gas purification device 3 using screws or the like. Therefore, when the heat recovery device 4 is attached to the exhaust gas purification device 3, the exhaust gas purification device 3 The driver must be inserted from below. However, parts and piping are densely packed inside the system, and a sufficient space for changing the direction of the driver is not provided in the system, so that assembly inside the system becomes difficult. Therefore, in consideration of workability, the heat recovery device 4 is attached to the exhaust gas purification device 3 outside the system instead of attaching the heat recovery device 4 to the exhaust gas purification device 3 inside the system. However, since the assembly of the battery module 2, the exhaust gas purification device 3, and the heat recovery device 4 assembled outside cannot be put into the system from the maintenance opening 33, the assembly is lifted by a crane and It was dropped from. Such an assembling method not only requires time and labor for lifting the crane, but also the heat recovery device 4 is in an unstable state hanging from the exhaust gas purification device 3 through a thin pipe. must not.

  However, if the connection member 27 that connects the exhaust gas purification device 3 and the heat recovery device 4 has an inclination with respect to the connection surface of the exhaust gas purification device 3 and the battery module 2, the battery module 2 that is assembled in advance outside the system. When the assembly of the exhaust gas purification device 3 is assembled in the system, the connecting member 27 faces the maintenance opening 33. That is, since the screw can be stopped at the connecting member 27 without changing the direction by inserting a driver from the maintenance opening 33, the exhaust gas purification device 3 and the heat recovery device 4 can be easily connected even in a narrow space. Assembling can be performed inside the system.

  On the other hand, in maintenance work, when a maintenance door (not shown) is first opened, components such as the battery module 2, the exhaust gas purification device 3, and the heat recovery device 4 are exposed from the maintenance opening 33. 4. Remove 4

  In the conventional structure, since the heat recovery device 4 is fixed to the bottom surface of the exhaust gas purification device 3 with a screw, in order to remove this screw, a driver must be inserted upward from below the exhaust gas purification device 3, It was not possible to confirm the place of the screw stop without bending and looking into from below. Furthermore, since there is not enough space to change the direction of the driver inserted from the maintenance opening 33 inside the system, the handling of the driver becomes very difficult. However, in the present embodiment, by tilting the connecting member 27, the operator can not bend and look into it from below, but can confirm the screw-fastening location from the front, and the driver inserted from the maintenance opening 33 can be confirmed. Since there is no need to change the direction, screws can be removed and attached smoothly.

  Further, since the connection member 27 faces in the direction in which the worker performs the maintenance work, there is no need to go around the side after opening the maintenance door, and the fuel cell system is excellent in maintenance workability.

  Further, since the heat recovery device 4 is screwed to the purified exhaust gas passage 26 via the connecting member 27, there is no possibility that the exhaust gas flowing through the purified exhaust gas passage 26 leaks from the screw hole 28. Can work safely.

Second embodiment

  FIG. 5 is a diagram showing a second embodiment of the exhaust gas purifying apparatus 3 according to the present invention. 5A is a cross-sectional view of the exhaust gas purification device 3, and FIG. 5B is a view showing the angle of the connection member 27. In the second embodiment, the cylindrical purification exhaust gas flow channel 26 is integrated with the bottom plate 24. FIG. It differs from the first embodiment in that it is molded. Further, since the bottom plate 24 forms the bottom surface of the exhaust gas purification device 3 and has a role of an attachment plate when the exhaust gas purification device 3 is attached to the battery module 2, the bottom plate 24 is connected to the exhaust gas purification device 3 and the battery module 2. It becomes a connecting surface.

  The purified exhaust gas flow path 26 is constituted by a single cylindrical pipe, and the connecting member 27 is inclined with respect to the bottom plate 24 by bending the pipe.

  Thus, since the bottom plate 24 and the purified exhaust gas passage 26 are integrally formed, the number of parts and the welding process can be reduced, so that the manufacturing cost can be reduced.

  In the second embodiment, the heater 22 is not embedded in the purification catalyst 20 and is provided upstream of the purification catalyst 20. The fluid flowing into the exhaust gas purification device 3 from the exhaust gas passage 12 passes through the purification catalyst 20 after passing through the heater 22 and becoming high temperature. That is, the purification catalyst 20 is maintained at the activation temperature by the heat of the exhaust gas.

Third embodiment

  FIG. 6 is a view showing a third embodiment of the exhaust gas purifying apparatus 3 according to the present invention. FIG. 6A is a cross-sectional view of the exhaust gas purification device 3, and FIG. 6B is a view showing the angle of the connection member 27. The third embodiment is the same as the second embodiment in that the purified exhaust gas flow channel 26 is integrally formed on the bottom plate 24, but the shape of the purified exhaust gas flow channel 26 is different. That is, the convex portion protruding downward from the bottom plate 24 by the drawing process becomes the purified exhaust gas passage 26, and the connecting member 27 is joined to the side wall 26a of the convex portion.

  When the dimensional error of the angle θ between the connecting member 27 and the bottom plate 24 or the distance between the exhaust gas purification device 3 and the heat recovery device 4 increases, the position (installation plane direction or height direction) where the heat recovery device 4 is installed is changed. There is a need. However, within the system in which parts and piping are densely packed, the allowable change range of the installation position is limited. Therefore, if the exhaust gas purification device 3 is connected without changing the installation position of the heat recovery device 4, stress is applied to the piping portion through which the purified exhaust gas flows between the exhaust gas purification device 3 and the heat recovery device 4, and the durability of the piping portion is increased. There is a risk of deteriorating the performance.

  Possible causes of this error include the angle at which the purified exhaust gas flow channel 26 and the connecting member 27 are joined, and a dimensional error when the purified exhaust gas flow channel 26 is molded. However, according to the present embodiment, the purified exhaust gas passage 26 is formed into a fixed shape by drawing, and the angle of the connecting member 27 is fixed by the side wall 26a, so that the angle θ can be easily and accurately maintained. Therefore, it is possible to improve the ease of manufacture and assembly, and further the durability.

Further, according to this, the temperature of the purified exhaust gas decreases due to an excessive flow channel surface area between the exhaust gas purification device 3 and the heat recovery device 4, and the pressure of the purified exhaust gas between the exhaust gas purification device 3 and the heat recovery device 4 Since it is possible to suppress the loss from becoming excessive, it is also possible to suppress a decrease in power generation efficiency.

  The convex portion of the purified exhaust gas flow channel 26 may be joined to the purified exhaust gas outlet portion of the bottom plate 24 after the convex portion of the purified exhaust gas flow channel 26 is independently molded. Further, it may be integrally formed with the bottom plate 24. In this case, since the bottom plate 24 and the purified exhaust gas passage 26 are integrally formed, the number of parts and the welding process can be reduced, so that the manufacturing cost can be reduced.

  The inclination θ of the connecting member 27 with respect to the bottom plate 24 can be changed as appropriate by changing the throttle shape of the purified exhaust gas passage 26. For example, in FIG. 6, the inclination θ becomes an acute angle by making the side wall 26 a constricted downward. On the other hand, in FIG. 7, since the side wall 26a is orthogonal to the bottom plate 24, the inclination θ is a right angle.

The illustrated embodiments are merely examples of the present invention, and the present invention includes various improvements and modifications made by those skilled in the art within the scope of the claims in addition to those directly illustrated by the described embodiments. Needless to say, it is included.

  For example, as the first to third embodiments, the substantially quadrangular connection member 27 is shown, but the shape of the connection member is not limited to this, and any shape that does not cause gas leakage with the heat recovery device 4 is possible. Good. Further, the connecting member 27 may be provided with a bead. By providing the bead, when the connecting member 27 and the heat recovery device 4 are screwed, a higher pressure is applied to the bead portion than the others, so that the adhesion of the connection portion can be further enhanced.

Moreover, although the spiral heater 22 was illustrated as 1st-3rd embodiment, it is not restricted to this, For example, a rod shape may be sufficient and planar which is located substantially perpendicular | vertical with respect to the flow direction of waste gas. It may be a simple shape.

  Moreover, although the purification catalyst case 21 illustrated the substantially cylindrical cylinder, polygonal box shape may be sufficient.

2 Battery module (power generation device)
DESCRIPTION OF SYMBOLS 3 Exhaust gas purification apparatus 4 Heat recovery apparatus 26 Purified exhaust gas flow path 27 Connection member

Claims (7)

  A power generation device that generates power, an exhaust gas purification device that purifies exhaust gas discharged from the power generation device, and a heat recovery device that recovers heat from the exhaust gas that has passed through the exhaust gas purification device, the exhaust gas purification device and the A cogeneration system characterized in that a connecting portion for connecting a heat recovery device has an inclination of a predetermined angle with respect to a connecting surface between the exhaust gas purification device and the power generation device.   The cogeneration system according to claim 1, wherein the connection portion faces a direction in which a heat recovery apparatus is attached.   The cogeneration system according to claim 2, wherein the exhaust gas purification device is disposed at a bottom portion of the power generation device, and the heat recovery device is disposed between the exhaust gas purification device and a heat recovery device mounting work surface. system.   The exhaust gas purification device further includes a purified exhaust gas passage through which the purified exhaust gas passes, and the connection portion is provided in the purified exhaust gas passage. Cogeneration system.   The cogeneration system according to any one of claims 1 to 4, wherein the exhaust gas purification device and the purified exhaust gas flow path are integrally formed.   The cogeneration system according to any one of claims 1 to 5, wherein the inclination of the connecting portion is 45 to 90 °.   The cogeneration system according to any one of claims 1 to 6, wherein the connection portion is a plate-like connection member, and the connection member has a screw hole.

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