JP2012159274A - Electric power generation system, and method for operating the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve ignitability of a combustor as compared to conventional combustors, in an electric power generation system having the combustor therein and configured so that a combustion exhaust gas discharged from the combustor and a burning exhaust gas discharged from a burning device join together.SOLUTION: The electric power generation system includes: an electric power generation unit having the combustor; a first exhaust gas flow path through which the combustion exhaust gas discharged from the combustor flows; and a control unit. The first exhaust gas flow path is connected to a duct that is connected to a second exhaust gas flow path through which the burning exhaust gas discharged from the burning device that generates heat to be fed to a heat load flows. When starting an ignition operation of the combustor while the burning device is in a burning operation, the control unit controls, during the ignition operation of the combustor, the burning device to output a lower power than the output before the start of the ignition operation of the combustor.

Description

  The present invention relates to a power generation system having a combustor inside and having an exhaust gas flow channel connected to a common duct with a combustion device.

  2. Description of the Related Art Conventionally, a power generation device is known in which an exhaust gas flow path is connected to a duct extending in the vertical direction for the purpose of improving the exhaust performance of exhaust gas generated by a power generation device including a fuel cell disposed inside a building ( For example, see Patent Document 1).

  In addition, a power generator equipped with a fuel cell ignites a burner of a reformer that supplies reformed gas to the fuel cell at the time of startup, and raises the reformer to a predetermined temperature suitable for the reforming reaction. It is known (see, for example, Patent Document 2).

  Further, it is known that a gas engine power generator ignites a gas engine at the time of startup and generates electric power by rotational driving accompanying combustion of the gas engine (see, for example, Patent Document 3).

JP 2008-210631 A JP 2004-283071 A JP 2007-205293 A

  By the way, in the electric power generating apparatus described in patent document 1, the exhaust gas of a fuel cell is comprised so that it may connect to a duct. When there is a combustion device (hereinafter referred to as a combustion device) for supplying heat to the heat load outside such a power generation device, it is assumed that the exhaust gas flow path of the combustion device is also connected to the duct. In such a form, when the combustion device is operating, the back pressure of the exhaust gas flow path of the combustor is increased through the duct, and the ignition operation of the combustor as described in Patent Document 2 and Patent Document 3 is performed. Although a bad influence may arise, the conventional power generation device is not examined about the point.

  The present invention has been made in order to solve such problems, and in a power generation system configured to have a combustor inside, and configured so that combustion exhaust gas from the combustor merges with combustion exhaust gas of the combustion device, An object of the present invention is to provide a power generation system in which the ignitability of a combustor is improved as compared with the conventional one and an operation method thereof.

  In order to solve the above problems, a power generation system of the present invention includes a power generation unit including a combustor, a first exhaust gas passage through which combustion exhaust gas discharged from the combustor flows, and a controller. The exhaust gas passage 1 is connected to a duct connected to a second exhaust gas passage through which the combustion exhaust gas from the combustion device that generates heat supplied to the heat load flows, and the combustion is performed during the combustion operation of the combustion device. When starting the ignition operation of the combustor, the controller controls the output of the combustion device to be lower than that before the start of the ignition operation of the combustor during the ignition operation of the combustor.

  The operation method of the power generation system of the present invention includes a step in which the combustion exhaust gas from the combustor provided in the power generation unit merges with the combustion exhaust gas from the combustion device, a step of performing an ignition operation of the combustor, When the ignition operation of the combustor is started during the combustion operation of the combustion device, the output of the combustion device is reduced during the ignition operation of the combustor than before the ignition operation of the combustor is started.

  According to the present invention, the ignitability of the combustor is improved as compared with the conventional power generation system having the combustor inside and configured so that the combustion exhaust gas from the combustor merges with the combustion exhaust gas of the combustion device.

The figure which shows typically schematic structure of the electric power generation system which concerns on Embodiment 1. FIG. 1 is a block diagram illustrating an example of a schematic configuration of a power generation system according to Embodiment 1. FIG. Flow chart showing an example of operation of the power generation system according to Embodiment 1 Flow chart showing an example of the operation of the power generation system according to Modification 2 of Embodiment 1 FIG. 3 is a block diagram illustrating an example of a schematic configuration of a power generation system according to Embodiment 2. Block diagram showing an example of a schematic configuration of a power generation system according to Embodiment 3 The figure which shows the example of a display of the remote control of the electric power generation system which concerns on Embodiment 3.

  Hereinafter, specific embodiments will be described with reference to the drawings.

(Embodiment 1)
The power generation system according to Embodiment 1 includes a power generation unit including a combustor, a first exhaust gas passage through which combustion exhaust gas discharged from the combustor flows, and a controller. When communicating with the second exhaust gas flow path through which the combustion exhaust gas from the combustion device that generates heat to be supplied to the load flows, and when starting the ignition operation of the combustor during the combustion operation of the combustion device, the controller During the ignition operation, the output of the combustion device is controlled to be lower than before the start of the ignition operation of the combustor.

  The operation method of the power generation system of the first embodiment includes a step in which combustion exhaust gas from a combustor provided in a power generation unit joins combustion exhaust gas from a combustion device, a step of performing an ignition operation of the combustor, and a combustion When the ignition operation of the combustor is started during the combustion operation of the apparatus, the output of the combustion device is reduced during the ignition operation of the combustor than before the ignition operation of the combustor is started.

  With such a configuration, the ignitability of the combustor is improved as compared with the conventional power generation system having the combustor inside and the exhaust gas flow path connected to a common duct with the combustion apparatus.

  Here, the first exhaust gas flow path “communicates” with the second exhaust gas flow path means that the first exhaust gas flow path and the second exhaust gas flow path are directly connected, and the first exhaust gas flow path. And a mode in which the passage and the second exhaust gas passage communicate with each other through a duct.

  Here, the reduction of the output of the combustion apparatus includes not only the reduction of the combustion amount of the combustion apparatus but also the stop of the combustion operation of the combustion apparatus.

  In the power generation system of the first embodiment, the controller may release the restriction on the output of the combustion device during the ignition operation of the combustor after the completion of the ignition operation of the combustor.

  The operation method of the power generation system according to Embodiment 1 may include a step of releasing the restriction on the output of the combustion device during the ignition operation of the combustor after the completion of the ignition operation of the combustor.

  Such a configuration is preferable because after the ignition operation is completed, the combustion apparatus can be operated at a required output for the heat load demand.

  Next, details of the power generation system according to Embodiment 1 will be described.

[Constitution]
1 is a block diagram illustrating an example of a schematic configuration of a power generation system according to Embodiment 1. FIG.

  As shown in FIG. 1, the power generation system 101 includes a power generation unit 1 including a combustor 3, a first exhaust gas flow path 4, and a controller 22.

  The power generation unit 1 is a power generation unit including the combustor 3, and examples thereof include a fuel cell unit and a gas engine power generation unit. The power generation unit 1 discharges exhaust gas in the power generation operation.

  The combustor 3 is a combustor that combusts a combustible gas. As such a combustor 3, a gas engine in a gas engine generator, an anode off-gas combustor in a fuel cell, and hydrogen used for power generation in the fuel cell. The combustor etc. which heat the reformer which produces | generates a containing gas are illustrated.

  The first exhaust gas channel 4 is a gas channel through which the combustion exhaust gas discharged from the combustor 3 flows, and is connected to the second exhaust gas channel 6. At the junction 21, the first exhaust gas channel 4 and the second exhaust gas channel 6 are merged. The first exhaust gas flow path 4 and the second exhaust gas flow path 6 after joining are connected to a duct 11, and combustion exhaust gas is discharged to the outside air through the duct.

  The first exhaust gas channel 4 and the second exhaust gas channel 6 are not directly connected, and the first exhaust gas channel 4 and the second exhaust gas channel 6 are independent from each other as shown in FIG. The first exhaust gas flow channel 4 and the second exhaust gas flow channel 6 may be configured to communicate with each other via the duct 11. That is, as long as the first exhaust gas channel 4 and the second exhaust gas channel 6 communicate with each other, any form may be used.

  The second exhaust gas channel 6 is a channel through which the combustion exhaust gas from the combustion device 5 flows.

  The combustion device 5 is a device that generates heat for burning fuel gas and supplying it to a heat load (not shown). Examples of the combustion device 5 include a boiler and a water heater. The combustion device 5 combusts fuel gas during a combustion operation and discharges combustion exhaust gas containing water (hereinafter referred to as combustion exhaust gas). Examples of the heat load (not shown) include heating, a bath, and a shower.

  The controller 22 controls the operation of the combustion device 5. The controller only needs to have a control function, and includes an arithmetic processing unit (not shown) and a storage unit (not shown) for storing a control program. Examples of the arithmetic processing unit include an MPU and a CPU. An example of the storage unit is a memory. The controller may be composed of a single controller that performs centralized control, or may be composed of a plurality of controllers that perform distributed control in cooperation with each other. In the case of centralized control, the controller 22 directly controls the combustion device 5, and in the case of distributed control, the controller 22 indirectly through a controller (not shown) that controls the combustion device 5. Then, the combustion device 5 is controlled.

  In addition, the power generation system 101 includes an ON detector (not shown) that detects ON of the combustion device 5 (execution of the combustion operation). The ON detector includes, for example, a signal acquisition device that acquires an ON signal of the combustion device 5 output from the combustion device 5, a pressure detector that detects the pressure of the combustion exhaust gas discharged from the combustion device 5, and the like.

  In this example, the combustion apparatus 5 and the second exhaust gas flow path 6 are described as being not included in the power generation system 101. However, a form in which these are included in the power generation system 101 may be adopted.

[Operation]
Next, the control of the controller 22 in the power generation system 101 configured as described above will be described with reference to FIG.

  FIG. 3 is a flowchart showing an example of the operation of the power generation system 101 of the present embodiment.

  This control is executed when the ignition operation for starting the combustion operation of the combustor 3 is performed regardless of the operation state of the power generation system 101, but the presence or absence of execution is controlled according to the operation state. You may adopt. Here, examples of the operation state include a start operation of the power generation system 101, a power generation operation, a stop operation, and a standby state. Here, the standby state refers to a state where the stopping operation of the power generation system 101 is completed and waiting for the next activation. When the power generation system 101 is activated, the power generation unit 1 generates power.

  On the other hand, as shown in FIG. 3, the controller 22 determines whether or not the combustion device 5 is ON (performs a combustion operation) based on a detection value of an ON detector (not shown) (step S1). When the combustion apparatus 5 is ON (YES in step S1), the controller 22 controls the output of the combustion apparatus 5 to decrease (step S2). In this example, a controller (not shown) provided in the combustion device 5 is instructed to control the output of the combustion device 5. Thereby, the combustion apparatus 5 is controlled by a controller (not shown) so that the output of the combustion apparatus 5 decreases. In this example, the controller (not shown) is controlled so that the supply amount of the combustible gas supplied to the combustion device 5 is reduced, and the combustion amount of the combustion device 5 is reduced. Here, since the flow rate of the combustion exhaust gas flowing through the second exhaust gas channel 6 decreases, the back pressure of the first exhaust gas channel 4 also decreases. In addition, if the supply amount of combustion air is reduced together with the reduction of the supply amount of the combustible gas supplied to the combustion device 5, the back pressure of the first exhaust gas passage 4 is further reduced during the ignition operation of the combustor 3. Therefore, it is preferable. Here, the supply amount of the combustible gas and the supply amount of the combustion air are respectively adjusted by a flow rate regulator (not shown). As the flow rate regulator, either a flow rate regulating valve or a pump, or a combination thereof is used.

  After reducing the output of the combustion device 5, the controller 22 performs an ignition operation of the combustor 3 using an igniter (not shown) (step S3). Note that in this step, the output of the combustion device 5 is limited so as to operate below the output reduced in step S2. When it is detected that the combustor 3 has ignited by a flame detector (not shown) during the ignition operation, the controller 22 stops the ignition operation and releases the output restriction of the combustion device 5 (step S4). . In this example, a signal for releasing the output restriction of the combustion device 5 is output to a controller (not shown) of the combustion device 5. The controller (not shown) of the combustion device 5 releases the output restriction of the combustion device 5 and changes the output to supply heat necessary for the heat load demand. In addition, in this example, it is the flow which performs the ignition operation | movement of the combustor 3 after reducing the output of the combustion apparatus 5, However, These timings may be simultaneous and may be reverse. . That is, if the output of the combustion device 5 is lower in the ignition operation of the combustor 3 than before the ignition operation, the timing for executing the steps S2 and S3 is arbitrary.

  On the other hand, when the combustion device 5 is not ON in step S1 (NO in step S1), the controller 22 executes an ignition operation of the combustor 3 using an igniter (not shown) (step S1). S5). Then, when it is detected by the flame detector (not shown) that the combustor 3 has ignited, the controller 22 stops the ignition operation.

  In the above flow, step S4 is executed, but step S4 is not executed, and after the ignition operation of the combustor 3 is completed, the output of the combustion device 5 is limited until the combustion of the combustor 3 becomes stable. You may employ | adopt the form to maintain.

  Next, a modification in the first embodiment will be described.

[Modification]
The power generation system according to the present modification is the power generation system according to Embodiment 1, wherein the controller stops the combustion operation of the combustion device during the ignition operation of the combustor.

  The operation method of the power generation system of the present modification is characterized in that, in the operation method of the power generation system of the first embodiment, the step of reducing the output of the combustion device is a step of stopping the combustion operation of the combustion device. .

  With this configuration, the back pressure of the first exhaust gas flow path 4 due to the combustion operation of the combustion device 5 is not increased, so that the combustor is less than the power generation system of the first embodiment that reduces the combustion amount of the combustion device 5. The ignitability of No. 3 is further improved, which is preferable.

  The power generation system according to the present modification may be configured in the same manner as the power generation system according to the first embodiment, except for the above characteristics.

  Next, the power generation system 101 of this modification will be described in detail.

  The power generation system according to the present modification is the power generation system according to the first embodiment. In the power generation system according to the first embodiment, the controller starts the ignition operation of the combustor after post-purging the combustion device with combustion air after the combustion operation of the combustion device is stopped. You may control so.

  The operation method of the power generation system according to the present modification is the operation method of the power generation system according to the first embodiment. In the ignition operation of the combustor, after the combustion operation of the combustion device is stopped, the combustion device is posted with combustion air. After purging, the ignition operation of the combustor may be started.

  With such a configuration, the ignition operation is performed in a state where there is no increase in the back pressure of the first exhaust gas flow path 4 due to the post purge of the combustion device 5, so that compared with the case where the ignition operation is performed during the post purge. The ignitability of the combustor 3 is improved, which is more preferable.

  The power generation system of the present modification may be configured in the same manner as the fuel cell system of Embodiment 1 except for the above features.

  Since the power generation system 101 of this modification has the same configuration as that of the power generation system of the first embodiment, the description thereof will be omitted, and the operation of the power generation system 101 of this modification will be described.

  FIG. 4 is a flowchart showing an example of the operation of the power generation system 101 in the modification of the first embodiment.

  As shown in FIG. 4, the power generation system 101 of this modification example performs the combustion operation of the combustion device 5 when detecting that the combustion device 5 is ON (execution of the combustion operation) (Yes in step S1). The operation is the same as in FIG. 3 except that the operation is stopped (step S6), the combustion of the combustor 3 is ignited (step S3), and the combustion operation of the combustion device 5 is resumed (step S7).

  In this example, in step S7, the controller 22 controls to resume the combustion operation of the combustion device 5 upon completion of the ignition operation of the combustor 3. However, without providing step S7, the operator's manual operation is performed. The combustion apparatus 5 may be stopped until a new operation resumption instruction is issued by an operation or the like.

  Note that, when the combustion apparatus 5 is stopped, post-purge with combustion air is generally performed as a stop operation, thereby increasing the back pressure of the first exhaust gas flow path 4. It is preferable to perform control so that the ignition operation of the combustor 3 is started after obtaining a post-purge completion signal. However, when the back pressure during the post purge is lower than the back pressure before the ignition operation of the combustion device 5, a form in which the ignition operation of the combustor 3 is executed during the post purge may be adopted.

(Embodiment 2)
The power generation system of Embodiment 2 includes a first flow rate regulator that adjusts the flow rate of combustible gas supplied to the combustor, and a second flow rate regulator that adjusts the flow rate of combustion air supplied to the combustor. The controller includes a first flow rate regulator and a second flow rate so that the air ratio during the ignition operation of the combustor is lower than the air ratio during the ignition operation of the combustor when the combustion device is stopped. At least one of the regulators may be controlled.

  The operation method of the power generation system according to the second embodiment is supplied to the combustor so that the air ratio during the ignition operation of the combustor is lower than the air ratio during the ignition operation of the combustor when the combustion device is stopped. A step of controlling at least one of the amount of fuel gas and the amount of combustion air supplied to the combustor may be provided.

  With such a configuration, the air ratio during the ignition operation of the combustor is reduced and the fuel gas concentration is increased compared to the case where the air ratio during the ignition operation of the combustor is made constant regardless of the operating state of the combustion device. The ignitability of the combustor is further improved.

  Here, the air ratio means the ratio of the amount of air actually supplied to the combustor to the theoretical amount of air necessary to completely burn the combustible gas supplied to the combustor.

  The power generation system according to the present embodiment may be configured in the same manner as the power generation system according to the first embodiment and the modifications thereof, except for the above characteristics.

  Next, the power generation system 101 of the present embodiment will be described in detail.

  FIG. 5 is a block diagram illustrating an example of a schematic configuration of the power generation system according to the second embodiment.

  As shown in FIG. 5, the power generation system 101 includes a first flow rate regulator 7 and a second flow rate regulator 8. Since the configuration other than the above and having the same reference numerals as those in FIGS. 1 and 2 is configured in the same manner as the power generation system 101 of Embodiment 1, the description thereof is omitted.

  The first flow rate adjuster 7 adjusts the flow rate of the combustible gas supplied to the combustor 3. The first flow rate regulator 7 is configured by, for example, one of a flow rate regulation valve and a pump, or a combination thereof.

  The second flow rate adjuster 8 adjusts the flow rate of the combustion air supplied to the combustor. The second flow rate regulator 8 is constituted by, for example, one of a flow rate regulation valve and a pump, or a combination thereof.

  Next, the operation of the power generation system 101 configured as described above will be described.

  In the power generation system 101 of the present embodiment, in the ignition operation of the combustor 3, the controller 22 controls at least one of the first flow rate regulator 7 and the second flow rate regulator 8, and the combustor 3 is controlled so that the air ratio during the ignition operation of 3 is lower than the air ratio during the ignition operation of the combustor 3 when the combustion device 5 is stopped.

  Specifically, the controller 22 controls the first flow rate regulator 7 to increase the flow rate of the combustible gas supplied to the combustor 3 and to reduce the air ratio. 22 controls at least one of the second controls for controlling the second flow rate regulator 8 to decrease the flow rate of the combustion air supplied to the combustor 3 and increase the air ratio.

  Since the concentration of the combustible gas with respect to the combustion air supplied to the combustor increases due to the decrease in the air ratio, the ignitability of the combustor 3 is improved, which is preferable.

  Except for the above-described control in the ignition operation of the combustor 3, the operation flow is the same as that of any one of the first embodiment and the modification thereof, and the description thereof will be omitted.

(Embodiment 3)
In the power generation system of the third embodiment, the controller displays on the display screen that the output of the combustion device is being reduced during the ignition operation of the combustor.

  Such a configuration is preferable because the user will not erroneously determine an abnormality even if a desired amount of heat cannot be obtained in the heat load during the ignition operation of the combustor.

  The power generation system according to the present embodiment may be configured in the same manner as the power generation system according to any one of Embodiments 1-2 and the modified example, except for the above characteristics.

  Next, the power generation system 101 of the present embodiment will be described in detail.

  FIG. 6 is a block diagram illustrating an example of a schematic configuration of the power generation system according to Embodiment 3.

  As shown in FIG. 6, the power generation system 101 includes a display device 10. Since the configuration other than the above and having the same reference numerals as those in FIGS. 1, 2, and 5 is configured in the same manner as the power generation system 101 of Embodiment 1, the description thereof is omitted.

  The display device 10 has a screen and displays predetermined information on the screen. The display device 10 may have any form as long as the display device has a screen, such as a remote control of the power generation system 101.

  In the power generation system 101 according to the present embodiment, when the output of the combustion apparatus 5 is reduced in the ignition operation of the combustor 3, the controller 22 performs control so that the fact is displayed on the screen of the display 10. Although the display format is arbitrary, for example, the fact that the output of the combustion device 5 is reduced due to the ignition operation of the combustor 3 is displayed by text or a code. Note that the reduction in the output of the combustion device 5 includes at least one of the reduction in the combustion amount of the combustion device 5 and the stop of the combustion device 5.

  FIG. 7 is a diagram illustrating a display example of the display of the power generation system according to the third embodiment.

  When the combustion amount of the combustion device 5 is reduced by the controller 22 during the ignition operation of the combustor 3 as compared with before the ignition operation, the fact is displayed on the screen of the display 10 as shown in FIG. Is displayed. Further, when the combustion device 5 is stopped by the controller 22 during the ignition operation of the combustor 3, that effect is displayed on the screen of the display 10 as shown in FIG.

  In the above example, the display 10 may not be included in the power generation system 101. In this case, the display 10 is exemplified by a remote controller of the combustion device 5, a television receiver, or the like.

  From the above description, many modifications and other embodiments are apparent to persons skilled in the art. Accordingly, the above description should be construed as illustrative only.

  A power generation system and an operation method thereof according to the present invention include a combustor inside, and a power generation system configured such that combustion exhaust gas from the combustor merges with combustion exhaust gas of the combustion device. Since ignitability improves, it is useful.

DESCRIPTION OF SYMBOLS 1 Power generation unit 3 Combustor 4 1st exhaust gas flow path 5 Combustion device 6 2nd exhaust gas flow path 7 1st flow regulator 8 Second flow regulator 10 Display 11 Duct 21 Merge location 22 Controller 101 Power generation system

Claims (12)

A power generation unit including a combustor, a first exhaust gas passage through which combustion exhaust gas discharged from the combustor flows, and a controller, wherein the first exhaust gas passage generates heat to be supplied to a heat load. When the combustion device is in communication with the second exhaust gas flow path through which the combustion exhaust gas flows, and starts the ignition operation of the combustor during the combustion operation of the combustion device, the controller performs the ignition operation of the combustor. A power generation system that controls the output of the combustion device to be lower than before the ignition operation of the combustor starts. A first flow rate regulator for regulating the flow rate of the fuel gas supplied to the combustor;
A second flow rate regulator for regulating the flow rate of combustion air supplied to the combustor,
The controller includes the first flow rate regulator and the first flow controller so that an air ratio during the ignition operation of the combustor is lower than an air ratio during the ignition operation of the combustor when the combustion device is stopped. The power generation system according to claim 1, wherein at least one of the two flow regulators is controlled. The power generation system according to claim 1, wherein the controller stops the combustion operation of the combustion device during the ignition operation of the combustor. 4. The power generation system according to claim 3, wherein the controller performs control so that an ignition operation of the combustor is started after the inside of the combustion device is post-purged with combustion air after the combustion operation of the combustion device is stopped. 5. The power generation system according to claim 1, wherein after the ignition operation of the combustor is completed, the controller releases the restriction on the output of the combustion device during the ignition operation of the combustor. A display for displaying the operating state of the combustion device on a screen;
The power generation system according to any one of claims 1 to 4, wherein the controller causes the display to display that the output of the combustion device is reduced during an ignition operation of the combustor. A step where the flue gas from the combustor provided in the power generation unit merges with the flue gas from the combustion device;
Performing an ignition operation of the combustor;
In the case where the ignition operation of the combustor is started during the combustion operation of the combustion device, the power generation includes the step of reducing the output of the combustion device during the ignition operation of the combustor than before the start of the ignition operation of the combustor. How to operate the system. The amount of fuel gas supplied to the combustor and the combustor so that the air ratio during the ignition operation of the combustor is lower than the air ratio during the ignition operation of the combustor when the combustion device is stopped. The method for operating a power generation system according to claim 7, further comprising a step of controlling at least one of the amount of combustion air supplied. The operation method of the fuel cell system according to claim 7, wherein the step of reducing the output of the combustion device is a step of stopping a combustion operation of the combustion device. 10. The power generation system according to claim 9, wherein, in the ignition operation of the combustor, after the combustion operation of the combustion device is stopped, after the inside of the combustion device is post-purged with combustion air, the ignition operation of the combustor is started. how to drive. The operation method of the power generation system according to any one of claims 7 to 10, further comprising the step of releasing the restriction on the output of the combustion device during the ignition operation of the combustor after the completion of the ignition operation of the combustor. The operation method of the power generation system according to any one of claims 7 to 10, further comprising a step of displaying that the output of the combustion device is reduced on a display screen during an ignition operation of the combustor.

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