JP2018200166A - Hydrogen combustion boiler - Google Patents

Abstract

To provide a hydrogen combustion boiler enabling a more efficient purge of a hydrogen supply line.SOLUTION: A hydrogen combustion boiler 1 includes: a hydrogen supply line L100 connected to a burner 20 and supplying hydrogen gas G1 to the burner 20; a first shutoff valve V11 disposed in the hydrogen supply line L100 and opening/closing a flow passage of the hydrogen supply line L100; a purge line L200 connected to a portion in the vicinity of the first shutoff valve V11 at a secondary side of the first shutoff valve V11 and supplying inert gas G2 to the hydrogen supply line L100; first supply valves V31, V32 disposed in the purge line L200 and controlling a supply amount of the inert gas G2; and a control section 40 for controlling opening/closing of the first shutoff valve V11 and the first supply valves V31, V32. The control section 40 includes a post purge control section 41 for closing the first shutoff valve V11 when combustion of the hydrogen gas G1 in the burner 20 is stopped and opening the first supply valves V31, V32 only in a state where the first shutoff valve V11 is closed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen combustion boiler.

  Conventionally, hydrogen combustion boilers using hydrogen gas as fuel are known. Hydrogen combustion boilers are attracting attention because they do not generate carbon dioxide when fuel is burned.

  On the other hand, hydrogen gas, which is a fuel, has a higher combustion speed than hydrocarbon gas, and has a wide combustion range when mixed with air, preventing the flame generated in the burner from flowing back to the hydrogen supply line. There is a need to. In particular, it is conceivable that when the burner is stopped, hydrogen gas remains in the hydrogen supply line, and the hydrogen gas is mixed with air, thereby causing a flashback phenomenon when the burner is restarted.

  In view of this, a boiler has been proposed that purges hydrogen gas remaining in the hydrogen supply line by injecting an inert gas into the hydrogen supply line (see, for example, Patent Document 1).

JP 2010-65579 A

  The boiler disclosed in Patent Document 1 is useful in that the hydrogen supply line is purged with an inert gas, thereby improving the safety when the burner operation is stopped. In small once-through boilers that generate steam according to fluctuations in the required steam amount on the load side, boiler combustion frequently starts and stops. There has been a demand for a boiler capable of appropriately and efficiently purging inert gas when boiler combustion is started and stopped, and improving safety at the time of boiler operation stop and startup.

  Therefore, an object of the present invention is to provide a hydrogen combustion boiler capable of purging a hydrogen supply line more efficiently.

  The present invention includes a burner, a hydrogen supply line that is connected to the burner and supplies hydrogen gas to the burner, a shutoff valve that is disposed in the hydrogen supply line and opens and closes the flow path of the hydrogen supply line, and the shutoff A purge line connected to the vicinity of the shut-off valve on the downstream side of the valve and supplying an inert gas to the hydrogen supply line; and a first supply valve disposed in the purge line for adjusting the supply amount of the inert gas; A control unit that controls opening and closing of the shutoff valve and the first supply valve, and the control unit closes the shutoff valve when stopping combustion of hydrogen gas in the burner, and the shutoff valve The present invention relates to a hydrogen combustion boiler including a post purge control unit that opens the first supply valve only in a closed state.

  The hydrogen combustion boiler further includes a can body, the burner is disposed on an upper end surface of the can body, the hydrogen supply line is connected to the burner from above the burner, and the purge line is an oxygen It is preferable to supply a lighter inert gas.

  The post-purge control unit may control opening and closing of the first supply valve so as to supply an inert gas that is four times or more the volume of the hydrogen supply line between the burner and the shutoff valve. preferable.

Further, the control unit opens the first supply valve for a predetermined time before starting combustion of hydrogen gas by the burner, and then supplies the inert gas from the purge line, and then closes the first supply valve. A pre-purge control unit that opens the shutoff valve after the first supply valve is closed;
It is preferable that the pre-purge control unit allows the first supply valve to be opened only when the shut-off valve is closed.

  Further, it is preferable that the pre-purge control unit controls the opening and closing of the first supply valve so as to supply an inert gas that is four times or more the volume of the hydrogen supply line between the burner and the shutoff valve. .

  In addition, the control unit further includes an abnormality detection unit that closes the shut-off valve when an abnormality in combustion of hydrogen gas in the burner is detected, and after the shut-off valve is closed by the abnormality detection unit, It is preferable to perform control by the pre-purge control unit when combustion is started.

  The hydrogen combustion boiler further includes an orifice disposed in the purge line, and the pressure of the inert gas downstream of the orifice in the purge line is cut off in the hydrogen supply line in a minimum combustion state of the burner. The pressure is preferably set lower than the pressure of the hydrogen gas supplied to the downstream side of the valve.

  The pressure of the inert gas upstream of the orifice in the purge line is set higher than the pressure of hydrogen gas supplied downstream of the shutoff valve in the hydrogen supply line in the maximum combustion state of the burner. It is preferable.

  The hydrogen combustion boiler is further provided with a pressure detection unit that is disposed in the purge line and detects the pressure of the inert gas, and the control unit is configured such that the pressure of the inert gas detected by the pressure detection unit is a predetermined value. It is preferable to stop the combustion of hydrogen gas by the burner when the temperature is lower than that.

  The hydrogen supply line connected to the hydrogen combustion boiler is provided with a fuel main valve on the upstream side of the hydrogen combustion boiler, and the hydrogen combustion boiler branches from the purge line and is located near the downstream side of the fuel main valve. A branch purge line connected to the hydrogen supply line; and a second supply valve disposed on the branch purge line for opening and closing the branch purge line, wherein the control unit includes the shutoff valve from the fuel main valve. It is preferable to further include a shut-off valve upstream purge control unit that allows the hydrogen supply line to be purged only when the fuel source valve is closed when purging with an inert gas.

  Further, the hydrogen combustion boiler includes a flow path switching valve disposed downstream of a connection position with the purge line in the hydrogen supply line, and a downstream side of a connection position between the hydrogen supply line and the purge line, And an atmosphere release line connected to a hydrogen supply line upstream of the flow path switching valve, and an atmosphere release valve disposed in the atmosphere release line for opening and closing the atmosphere release line, And an atmosphere release valve that is disposed in the atmosphere release line and opens and closes the atmosphere release line, and the shut-off valve upstream purge control unit closes the flow path switching valve and opens the atmosphere release valve. It is preferable to purge the hydrogen supply line.

  Moreover, it is preferable that a hydrogen combustion boiler is further equipped with the flame arrester arrange | positioned downstream from the connection position with the said purge line in the said hydrogen supply line.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen combustion boiler which can purge a hydrogen supply line more efficiently can be provided.

It is a figure showing typically the composition of the hydrogen combustion boiler concerning a 1st embodiment of the present invention. It is a figure which shows typically the structure of the hydrogen combustion boiler which concerns on 2nd Embodiment of this invention. It is a figure which shows typically the structure of the hydrogen combustion boiler which concerns on the other example of this invention.

  Hereinafter, the hydrogen combustion boiler 1 which concerns on each embodiment of this invention is demonstrated, referring drawings.

[First Embodiment]
First, the hydrogen combustion boiler 1 which concerns on 1st Embodiment of this invention is demonstrated with reference to FIG.
The hydrogen combustion boiler 1 of the first embodiment is a boiler that uses hydrogen gas G1 as fuel. The hydrogen combustion boiler 1 is, for example, a once-through boiler. In the hydrogen combustion boiler 1, the hydrogen gas G1 is supplied from a line that supplies the hydrogen gas G1 to the burner 20 disposed in the can 10. The hydrogen gas G1 remaining in the line supplying the hydrogen gas G1 is purged by the inert gas G2 when the burner 20 is stopped and when the burner 20 is started. Hereinafter, the purge when the combustion of the burner 20 is stopped is referred to as a post purge, and the purge when the combustion of the burner 20 is started is referred to as a pre-purge. Further, purging of the hydrogen gas G1 staying between the fuel source valve V13 and the first cutoff valve V11 described later is referred to as cutoff valve upstream purge.

  As shown in FIG. 1, the hydrogen combustion boiler 1 includes a can body 10, a burner 20, a blower 30, and a control unit 40. The hydrogen combustion boiler 1 includes a hydrogen supply line L100, a purge line L200, a branch purge line L250, and an air supply line L300. The “line” in this specification is a general term for a flow path, a path, a pipe line, and the like.

  The can body 10 includes a lower header, a plurality of water pipes, an upper header (all not shown), a combustion chamber B, and the like, and heats water supplied to the can body 10 to generate steam. .

The burner 20 is disposed on the upper portion of the can 10. The burner 20 burns hydrogen gas G1 in the combustion chamber B of the can 10.
The blower 30 supplies combustion air (combustion air A <b> 1) to the burner 20.
The control unit 40 controls the combustion of the hydrogen combustion boiler 1. Details of the control unit 40 will be described later.

  The hydrogen supply line L100 supplies hydrogen gas G1 to the burner 20 as fuel. More specifically, the hydrogen supply line L100 has a downstream side connected to the burner 20 from above the burner 20, and an upstream side connected to a supply source (not shown) that supplies the hydrogen gas G1.

The hydrogen supply line L100 includes a flame arrester 50, a first shut-off valve V11 as a shut-off valve, a second shut-off valve V12, a flow rate adjusting valve V21, a fuel source valve V13, and a first atmosphere release unit 110. And are arranged.
The flame arrester 50 is disposed on the hydrogen supply line L100, and is disposed on the downstream side of a connection position with a purge line L200 described later. The flame arrester 50 prevents the backfire generated in the hydrogen supply line L100 from the burner 20 from proceeding upstream.

  The first cutoff valve V11 and the second cutoff valve V12 are disposed upstream of the frame arrester 50 in the hydrogen supply line L100. The first cutoff valve V11 and the second cutoff valve V12 are constituted by electromagnetic valves, and open and close the flow path of the hydrogen supply line L100. In the present embodiment, the second cutoff valve V12 is disposed on the upstream side of the first cutoff valve V11. The second cutoff valve V12 is disposed in the vicinity of the first cutoff valve V11.

  The flow rate adjustment valve V21 is disposed upstream of the second shutoff valve V12 in the hydrogen supply line L100. Specifically, the flow rate adjustment valve V21 is disposed on the upstream side of the first cutoff valve V11. The flow rate adjustment valve V21 adjusts the flow rate of the hydrogen gas G1 flowing through the hydrogen supply line L100. The flow rate adjustment valve V21 is configured by, for example, a gas governor.

  The fuel source valve V13 is disposed upstream of the flow rate adjustment valve V21. In the present embodiment, the fuel source valve V13 is disposed in the vicinity of the upstream side of the hydrogen combustion boiler (outside), is configured by a manual valve, and opens and closes the flow path of the hydrogen supply line L100.

  The first atmosphere opening portion 110 is disposed on the upstream side of the fuel source valve V13. The first atmosphere release unit 110 includes an atmosphere release line L500 and a first atmosphere release valve V51 disposed in the atmosphere release line L500. The first atmosphere release unit 110 opens the first atmosphere release valve V51 to perform inert gas purge and hydrogen replacement of the hydrogen supply line L100 on the upstream side of the fuel source valve V13.

The purge line L200 is a line that supplies the inert gas G2 to the can body 10 through the hydrogen supply line L100. The upstream side of the purge line L200 is connected to the supply source 60 of the inert gas G2, and the downstream side is connected between the first cutoff valve V11 and the flame arrester 50 in the hydrogen supply line L100. In the present embodiment, the purge line L200 is connected in the vicinity of the first cutoff valve V11.
As the inert gas G2, a gas having a lighter specific gravity than oxygen, such as nitrogen, helium, or neon, is used. In the present embodiment, nitrogen is used as the inert gas G2.

The first supply valves V31 and V32 and the orifice 70 are arranged in the purge line L200.
The first supply valves V31 and V32 are constituted by electromagnetic valves, and adjust the supply amount of the inert gas G2 by opening and closing the flow path of the purge line L200.

  The orifice 70 is disposed downstream of the first supply valve V32 in the purge line L200. The orifice 70 restricts the inert gas G2 flowing through the purge line L200 and lowers the pressure of the inert gas G2 flowing downstream.

  From the purge line L200, the inert gas G2 having a pressure higher than the pressure of the hydrogen gas G1 supplied to the downstream side of the first cutoff valve V11 in the hydrogen supply line L100 is supplied. That is, the pressure of the inert gas G2 upstream of the orifice 70 in the purge line L200 is higher than the pressure of the hydrogen gas G1 supplied downstream of the first shutoff valve V11 in the hydrogen supply line L100 in the maximum combustion state of the burner 20. Is set to be higher.

  The pressure of the inert gas G2 downstream of the orifice 70 in the purge line L200 is the pressure of the hydrogen gas G1 supplied downstream of the first shutoff valve V11 in the hydrogen supply line L100 in the minimum combustion state of the burner 20. Is set to be lower. Thereby, the pressure of the inert gas G2 downstream of the orifice 70 is determined by the sum of the pressure of the hydrogen gas G1 downstream of the first cutoff valve V11 in the hydrogen supply line L100 and the reverse pressure resistance of the first cutoff valve V11. Also lower.

  The branch purge line L250 is a line branched from the purge line L200. The branch purge line L250 is a line that bypasses the purge line L200 and supplies the inert gas G2 to the can 10. The branch purge line L250 supplies the inert gas G2 that flows to the burner 20 via the hydrogen supply line L100 via the flow rate adjustment valve V21, the second cutoff valve V12, and the first cutoff valve V11. The branch purge line L250 branches from the purge line L200 and is connected to the hydrogen supply line L100 in the vicinity of the downstream side of the fuel source valve V13. Specifically, the upstream side of the branch purge line L250 is connected to the purge line L200 between the first supply valve V31 and the supply source 60, and the downstream side is a fuel source valve V13 (manual valve provided outside the boiler). ) Near the downstream side. In the present embodiment, the downstream side of the branch purge line L250 is connected to the upstream side of the flow rate adjustment valve V21 in the hydrogen supply line L100.

The second supply valve V33 is arranged in the branch purge line L250.
The second supply valve V33 is configured by an electromagnetic valve, and opens and closes the flow path of the branch purge line L250 to adjust the supply amount of the inert gas G2 supplied from the branch purge line L250 to the hydrogen supply line L100. In other words, the second supply valve V33 is configured by an electromagnetic valve, and opens and closes the flow path of the branch purge line L250, and from the branch purge line L250 to the flow rate adjustment valve V21, the second cutoff valve V12, and the first cutoff valve V11. The supply amount of the inert gas G2 to be supplied is adjusted.

  The air supply line L300 supplies combustion air A1 to the burner 20. The upstream side of the air supply line L300 is connected to the blower 30. The downstream side of the air supply line L300 is connected to the burner 20.

  The control unit 40 controls opening and closing of the first cutoff valve V11, the second cutoff valve V12, the first supply valves V31 and V32, and the second supply valve V33. The control unit 40 controls the start and stop of the blower 30. The control unit 40 includes a post-purge control unit 41, a pre-purge control unit 42, and a shut-off valve upstream purge control unit 44.

The post-purge control unit 41 purges the hydrogen supply line L100 when the combustion of the hydrogen gas G1 in the burner 20 is stopped.
The pre-purge control unit 42 purges the hydrogen supply line L100 before the combustion of the hydrogen gas G1 by the burner 20 is started.

The shutoff valve upstream purge controller 44 purges the hydrogen supply line L100 between the fuel source valve V13 and the first shutoff valve V11. More specifically, the shutoff valve upstream purge control unit 44 activates the blower 30 to ventilate the inside of the can body 10, and connects the branch purge line L250 to the hydrogen supply line L100 and the hydrogen of the purge line L200. The hydrogen supply line L100 between the connection position to the supply line L100 is purged.
The operation of the shutoff valve upstream purge control unit 44 will be described later.

Next, the operation of the hydrogen combustion boiler 1 will be described.
When the combustion of the hydrogen gas G1 in the burner 20 is stopped, the post purge by the post purge control unit 41 is performed. First, the post-purge control unit 41 closes the first cutoff valve V11 and the second cutoff valve V12. By closing the first cutoff valve V11 and the second cutoff valve V12, the hydrogen supply line L100 is closed and the supply of the hydrogen gas G1 to the burner 20 is stopped.

  Next, the post-purge control unit 41 opens the first supply valves V31 and V32 for a predetermined time after the first cutoff valve V11 and the second cutoff valve V12 are closed, and performs post-purge. In the present embodiment, the post-purge control unit 41 allows the first supply valves V31 and V32 to be opened only when the first cutoff valve V11 (and the second cutoff valve V12) is closed. Thereby, it is possible to prevent the hydrogen gas G1 from being supplied to the burner 20 by mistake when performing the post purge.

  By opening the first supply valves V31 and V32, the inert gas G2 is supplied from the supply source 60 of the inert gas G2 to the hydrogen supply line L100 through the purge line L200. The inert gas G <b> 2 supplied to the hydrogen supply line L <b> 100 passes through the flame arrester 50 and is ejected from the burner 20. The hydrogen gas G1 ejected from the burner 20 is purged from the combustion chamber B of the can body 10 together with the combustion air A1 supplied to the burner 20 from the air supply line L300.

  Here, the post-purge control unit 41 supplies the first supply valve so as to supply an inert gas G2 that is at least four times the internal volume of the hydrogen supply line L100 between the outlet of the burner 20 and the first cutoff valve V11. Controls opening and closing of V31 and V32. In the present embodiment, the post-purge control unit 41 supplies a predetermined amount of the inert gas G2 to the hydrogen supply line L100 by opening the first supply valves V31 and V32 for a predetermined time. By supplying the inert gas G2 to the hydrogen supply line L100 at least four times the volume of the hydrogen supply line L100, the hydrogen gas G1 remaining in the hydrogen supply line L100 is diluted to 1% or less. By diluting the hydrogen gas G1 to 1% or less, the concentration of the hydrogen gas G1 remaining in the hydrogen supply line L100 deviates from the combustible range (4% to 75%).

  The post-purge control unit 41 closes the first supply valves V31 and V32 after purging the hydrogen supply line L100 with the inert gas G2 supplied from the purge line L200. Next, the post-purge control unit 41 stops the blower 30 and ends the combustion stop operation of the hydrogen gas G1 by the burner 20.

  Next, when the combustion of the hydrogen gas G1 by the burner 20 is started, pre-purge by the pre-purge control unit 42 is performed. First, the pre-purge control part 42 starts the air blower 30, and starts supply of the combustion air A1 to the burner 20 from the air supply line L300. Next, the pre-purge control unit 42 opens the first supply valves V31 and V32. By opening the first supply valves V31 and V32, the inert gas G2 is supplied from the supply source 60 of the inert gas G2 to the hydrogen supply line L100 through the purge line L200. The inert gas G <b> 2 supplied to the hydrogen supply line L <b> 100 passes through the flame arrester 50 and is ejected from the burner 20. In the present embodiment, the post-purge control unit 41 allows the first supply valves V31 and V32 to be opened only when the first cutoff valve V11 (and the second cutoff valve V12) is closed. Thereby, it is possible to prevent the hydrogen gas G1 from being supplied to the burner 20 by mistake when performing the post purge.

  Here, the pre-purge control unit 42 opens and closes the first supply valves V31 and V32 so as to supply an inert gas G2 that is four times or more the volume of the hydrogen supply line L100 between the burner 20 and the first cutoff valve V11. To control. In the present embodiment, the pre-purge control unit 42 supplies a predetermined amount of the inert gas G2 to the hydrogen supply line L100 by opening the first supply valves V31 and V32 for a predetermined time. The pre-purge control unit 42 purges the hydrogen supply line L100 with the inert gas G2 supplied from the purge line L200, and then closes the first supply valves V31 and V32.

  Next, the pre-purge control unit 42 opens the first cutoff valve V11 and the second cutoff valve V12. By opening the first cutoff valve V11 and the second cutoff valve V12, the hydrogen supply line L100 is opened, and the supply of the hydrogen gas G1 to the burner 20 is started. Thereby, the pre-purge control part 42 complete | finishes the combustion start operation | movement of the hydrogen gas G1 by the burner 20. FIG.

The shut-off valve upstream purge stays in the hydrogen supply line L100 when, for example, the hydrogen combustion boiler 1 is installed or when maintenance is performed by disassembling or removing all or part of the hydrogen supply line L100 of the hydrogen combustion boiler 1. For the purpose of discharging air to replace with the inert gas G2, and when performing maintenance of the hydrogen supply line L100, or when stopping the hydrogen combustion boiler 1 for a long period of time, the hydrogen gas G1 staying in the hydrogen supply line L100 is discharged. This is performed for the purpose of replacing with the inert gas G2.
Specifically, first, the cutoff valve upstream purge control unit 44 confirms that the fuel source valve V13 is closed. By confirming the closing of the fuel source valve V13, it is confirmed that the supply of the hydrogen gas G1 to the downstream side of the fuel source valve V13 in the hydrogen supply line L100 is confirmed.

  Next, the shutoff valve upstream purge control unit 44 activates the blower 30 to ventilate the can body 10 and opens the second shutoff valve V12 and the first shutoff valve V11. As a result, the hydrogen gas G1 staying between the fuel main valve V13 and the first shut-off valve V11 passes through the flame arrester 50 and can move to the burner 20. Next, the shutoff valve upstream purge control unit 44 opens the second supply valve V33. Thereby, the inert gas G2 is supplied from the supply source 60 to the burner 20 through the purge line L200, the branch purge line L250, and the hydrogen supply line L100. Thereby, the hydrogen gas G1 staying between the fuel source valve V13 and the first shutoff valve V11 is ejected from the burner 20 together with the inert gas G2. Therefore, the downstream side of the fuel supply valve V13 in the hydrogen supply line L100 is purged with the inert gas G2. The shutoff valve upstream purge control unit 44 closes the second supply valve V33, the first shutoff valve V11, and the second shutoff valve V12 after a predetermined time has elapsed. Thereby, the shut-off valve upstream purge control unit 44 ends the shut-off valve upstream purge.

According to the hydrogen combustion boiler 1 of 1st Embodiment demonstrated above, there exist the following effects.
(1) The hydrogen combustion boiler 1 includes a burner 20, a hydrogen supply line L100 that supplies hydrogen gas G1 to the burner 20, a first cutoff valve V11 disposed in the hydrogen supply line L100, and a downstream of the first cutoff valve V11. A purge line L200 connected to the vicinity of the first shutoff valve V11 on the side for supplying the inert gas G2 to the hydrogen supply line L100, and a first supply valve V31 disposed in the purge line L200 for adjusting the supply amount of the inert gas G2. , V32. Thus, by purging the hydrogen gas G1 in the hydrogen supply line L100 from the burner 20 to the first shutoff valve V11 with the inert gas G2, it is possible to prevent the hydrogen gas G1 from mixing with the air and entering the combustible range. It is possible to prevent the flashback phenomenon from occurring during the ignition of the burner 20. Further, a purge line L200 is connected in the vicinity of the downstream side of the first shutoff valve V11 in the hydrogen supply line L100. Thereby, the inert gas G2 can be supplied from the immediate vicinity of the 1st cutoff valve V11. Therefore, the hydrogen gas G1 remaining in the hydrogen supply line L100 from the burner 20 to the first cutoff valve V11 can be efficiently purged.
Further, the hydrogen combustion boiler 1 is configured to include a post-purge control unit 41, and before the combustion of the hydrogen gas G1 by the burner 20 is started in the post-purge control unit 41, the first supply valves V31 and V32 are set for a predetermined time. Open and supply the inert gas G2 from the purge line L200, then close the first supply valves V31 and V32, and allow the first shut-off valve V11 to open only when the first supply valves V31 and V32 are closed. It was. Thereby, it is possible to prevent the hydrogen gas G1 from being erroneously supplied when performing the post purge. Therefore, the safety of the hydrogen combustion boiler 1 can be further improved.

  (2) The hydrogen combustion boiler 1 was configured including the can body 10, and the burner 20 was disposed on the upper end surface of the can body 10. Further, the hydrogen supply line L100 was connected to the burner 20 from above the burner 20, and an inert gas G2 lighter than oxygen was further supplied from the purge line L200. As a result, the burner 20 and the hydrogen supply line L100 are positioned above the can body 10, so that the space between the first shutoff valve V11 and the burner 20 in the hydrogen supply line L100 is filled with an inert gas G2 that is lighter than oxygen. In this case, it is possible to prevent the inert gas G2 from being replaced with oxygen present inside the can 10. Therefore, mixing of oxygen into the hydrogen supply line L100 can be prevented.

  (3) The first supply valves V31 and V32 are configured to supply the post-purge control unit 41 with an inert gas G2 that is four times or more the volume of the hydrogen supply line L100 between the burner 20 and the first cutoff valve V11. Opening and closing was controlled. Thereby, when combustion of the hydrogen gas G1 in the burner 20 is stopped, the hydrogen gas G1 remaining in the hydrogen supply line L100 can be suitably purged.

  (4) The hydrogen combustion boiler 1 includes the pre-purge control unit 42, and before the combustion of the hydrogen gas G1 by the burner 20 is started in the pre-purge control unit 42, the first supply valves V31 and V32 are opened for a predetermined time. Then, the inert gas G2 was supplied from the purge line L200, and then the first supply valves V31 and V32 were closed, and after the first supply valves V31 and V32 were closed, the first cutoff valve V11 was opened. In addition, the first shutoff valve V11 is allowed to open only when the first supply valves V31 and V32 are closed. As a result, the hydrogen supply line L100 can be purged before the burner 20 is ignited, and hydrogen gas G1 can be prevented from being erroneously supplied when pre-purging is performed. Therefore, the safety of the hydrogen combustion boiler 1 can be further improved.

  (5) The pre-purge control unit 42 is controlled to open and close so as to supply an inert gas G2 that is at least four times the internal volume of the hydrogen supply line L100 from the outlet of the burner 20 to the first shutoff valve V11. It was. Thereby, the density | concentration of the hydrogen gas G1 remaining between the burner 20 and the 1st cutoff valve V11 can fully be reduced, and the burner 20 can be ignited more safely.

  (6) The hydrogen combustion boiler 1 is configured to include an orifice 70 disposed in the purge line L200, and the pressure of the inert gas G2 downstream of the orifice 70 in the purge line L200 is reduced to hydrogen in the minimum combustion state of the burner 20. The pressure was set lower than the pressure of the hydrogen gas G1 supplied to the downstream side of the first cutoff valve V11 in the supply line L100. Thereby, it can prevent that the 1st cutoff valve V11 opens from the downstream by the inert gas G2 supplied from the purge line L200.

  (7) The pressure of the inert gas G2 upstream of the orifice 70 in the purge line L200 is the pressure of the hydrogen gas G1 supplied downstream of the first shutoff valve V11 in the hydrogen supply line L100 in the maximum combustion state of the burner 20. Set higher than. Thereby, it is possible to prevent the hydrogen gas G1 from flowing back into the purge line L200.

  (8) The hydrogen combustion boiler 1 is branched from the purge line L200, the branch purge line L250 connected to the hydrogen supply line L100 in the vicinity of the downstream side of the fuel main valve V13, and the second supply for opening and closing the branch purge line L250. And a valve V33. Further, when the control unit 40 purges between the fuel source valve V13 and the first shutoff valve V11 with an inert gas, the shutoff that enables the hydrogen supply line L100 to be purged only when the fuel source valve V13 is closed. The valve upstream purge control unit 44 is included. Thereby, the space between the fuel main valve V13 and the first cutoff valve V11 can be replaced with the inert gas G2. Therefore, when the hydrogen combustion boiler 1 is installed, or when maintenance is performed by disassembling or removing all or part of the hydrogen supply line L100 of the hydrogen combustion boiler 1, the air staying in the hydrogen supply line L100 is discharged and not discharged. It can be replaced with the active gas G2. Further, when the maintenance of the hydrogen supply line L100 is performed or when the hydrogen combustion boiler 1 is stopped for a long time, the gas containing the hydrogen gas G1 staying in the hydrogen supply line L100 can be discharged and replaced with the inert gas G2. As a result, the safety of the hydrogen combustion boiler 1 can be improved.

  (9) The hydrogen combustion boiler 1 is configured to include the flame arrester 50 that is disposed downstream of the connection position with the purge line L200 in the hydrogen supply line L100. Thereby, even if a backfire occurs from the burner 20 in the hydrogen supply line L100, the backfire is prevented by the flame arrester 50, so that the backfire can be prevented from reaching the connection position of the purge line L200. . Therefore, damage to the purge line L200 due to flashback can be suppressed, and safety can be improved. In addition, an inert gas G <b> 2 is supplied toward the burner 20 from a hydrogen supply line L <b> 100 upstream of the flame arrester 50. Accordingly, the hydrogen gas G1 staying in the hydrogen supply line L100 inside and downstream of the flame arrester 50 can be diffused from the burner 20 to the outside. As a result, even if the flame arrester 50 has a reduced ability to prevent backfire due to breakage or dust, the backfire can be reduced and safety can be improved. Further, the inert gas G2 flows from the upstream side of the flame arrester 50 toward the burner 20, so that the concentration of the hydrogen gas G1 decreases from the burner 20 toward the upstream side of the hydrogen supply line L100. As a result, the possibility of backfire reaching the flame arrester 50 can be reduced, and burning of the flame arrester 50 due to backfire can be suppressed.

[Second Embodiment]
Next, a hydrogen combustion boiler 1A according to a second embodiment of the present invention will be described with reference to FIG. In the description of the second embodiment, the same constituent elements are denoted by the same reference numerals, and the description thereof is omitted or simplified.
1 A of hydrogen combustion boilers of 2nd Embodiment implement a pre purge only when starting combustion after having stopped abnormally. In this embodiment, the case where the start of combustion of the hydrogen gas G1 by the burner 20 is interlocked due to the abnormal combustion of the burner 20 or the pressure drop of the inert gas G2 will be described as an example.

  As shown in FIG. 2, the hydrogen combustion boiler 1 </ b> A according to the second embodiment is mainly the first in that it includes a pressure detection unit 80 and a burner monitoring unit 90, and the control unit 40 </ b> A includes an abnormality detection unit 43. Different from the embodiment.

  The pressure detection unit 80 is disposed in the purge line L200 and detects the pressure of the inert gas G2. The pressure detection unit 80 is disposed on the upstream side of the first supply valve V31, and detects the pressure of the inert gas G2 on the upstream side of the first supply valve V31. In the present embodiment, the pressure detector 80 is, for example, a pressure switch, and the pressure decreases when the pressure of the inert gas G2 flowing upstream from the first supply valve V31 is lower than a predetermined pressure. An abnormality signal indicating this is sent to an abnormality detection unit 43 described later.

  The burner monitoring unit 90 is constituted by a flame detector, for example, and monitors the combustion of the hydrogen gas G1 in the burner 20. The burner monitoring unit 90 indicates that an abnormality has occurred in combustion when an abnormality has occurred in the combustion of the hydrogen gas G1 in the burner 20 (for example, when flame detection is no longer performed when a combustion instruction is issued). An abnormality signal is sent to an abnormality detection unit 43 described later.

The abnormality detection unit 43 closes the first cutoff valve V11 and the second cutoff valve V12 when detecting an abnormality in combustion of the hydrogen gas G1 in the burner 20. More specifically, when the abnormality detection unit 43 acquires an abnormality signal from the burner monitoring unit 90, the abnormality detection unit 43 closes the first cutoff valve V11 and the second cutoff valve V12.
Moreover, the abnormality detection part 43 closes the 1st cutoff valve V11 and the 2nd cutoff valve V12, when the pressure fall of the inert gas G2 is detected. More specifically, when the abnormality detection unit 43 acquires an abnormality signal from the pressure detection unit 80, the abnormality detection unit 43 closes the first cutoff valve V11 and the second cutoff valve V12.
And the abnormality detection part 43 applies an interlock in the state which stopped combustion of the hydrogen gas G1 in the burner 20 based on the abnormality signal. That is, the abnormality detection unit 43 interlocks the automatic start of combustion of the hydrogen gas G1 by the burner 20.

  The pre-purge control unit 42 performs pre-purge when the interlock is released.

Next, the operation of the hydrogen combustion boiler 1A will be described.
When the burner monitoring unit 90 detects abnormal combustion of the hydrogen gas G1 during the operation of the hydrogen combustion boiler 1A, the burner monitoring unit 90 sends an abnormal signal to the abnormality detection unit 43. The abnormality detection unit 43 closes the first cutoff valve V11 and the second cutoff valve V12 and stops the supply of the hydrogen gas G1 to the burner 20. Further, the abnormality detection unit 43 interlocks the automatic start of the combustion of the hydrogen gas G1 by the burner 20 in a state where the supply of the hydrogen gas G1 is stopped.

  The pre-purge control unit 42 determines whether or not the interlock is released. The pre-purge control unit 42 performs pre-purge when the interlock is released.

According to 1 A of hydrogen combustion boilers of 2nd Embodiment demonstrated above, there exist the following effects.
(10) The control unit 40A includes the abnormality detection unit 43, and the control unit 40A is pre-purged when the combustion of the hydrogen gas G1 is started after the first cutoff valve V11 is closed by the abnormality detection unit 43. Control by the control unit 42 was performed. As a result, when the combustion of the hydrogen gas G1 by the burner 20 is normally stopped, only the post purge at the time of the combustion stop is performed, and when the combustion is stopped due to the abnormality detection, not only the post purge but also the combustion starts. A pre-purge is also performed before. Therefore, the burner 20 can be ignited more safely.

  (11) The hydrogen combustion boiler 1A includes a pressure detector 80 that is disposed in the purge line L200 and detects the pressure of the inert gas G2. Then, the combustion of the hydrogen gas G1 by the burner 20 was stopped when the pressure of the inert gas G2 detected by the pressure detection unit 80 decreased below a predetermined value. Thereby, when there is a possibility that the hydrogen supply line L100 between the burner 20 and the first shutoff valve V11 cannot be purged by the inert gas G2, the operation of the burner 20 can be stopped. Therefore, it is possible to prevent the hydrogen combustion boiler 1A from operating in a state where the inert gas G2 is insufficient, and it is possible to safely operate the hydrogen combustion boiler 1A.

  The preferred embodiments of the hydrogen combustion boiler according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed.

  For example, in the above-described embodiment, the purge line L200 is connected to the vicinity of the downstream side of the first shutoff valve V11, but is not limited thereto. For example, the purge line L200 may be connected to the hydrogen supply line L100 on the downstream side of the frame arrester 50. Thereby, consumption of the inert gas G2 used for purging can be suppressed.

  Moreover, in the said embodiment, although the flame arrester 50 was arrange | positioned in the hydrogen supply line L100, it is not restrict | limited to this. In other words, the frame arrester 50 may not be included. In this case, the purge line L200 may be connected to any position as long as it is downstream of the first cutoff valve V11.

  Moreover, in the said 2nd Embodiment, although the pressure switch was illustrated as the pressure detection part 80, it is not restrict | limited to this. For example, the hydrogen combustion boiler 1 is provided with a flow meter arranged in the purge line L200, and the abnormality detection unit 43 is the first when the flow rate of the inert gas G2 measured by the flow meter is lower than a predetermined amount. The shutoff valve V11 and the second shutoff valve V12 can be closed.

  In the above embodiment, the first supply valves V31 and V32 having a predetermined pressure loss may be used instead of the orifice 70. In this case, the pressure loss of the first supply valve V31 and the first supply valve V32 may be the same, or one of them may be larger.

  Moreover, in each said embodiment, although the fuel main valve V13 was comprised by the manual valve, it is not restricted to this. That is, the fuel source valve may be constituted by an air drive valve. In this case, the shut-off valve upstream purge control unit may electrically check the open / close state of the fuel source valve.

Moreover, in each said embodiment, as shown in FIG. 3, the hydrogen combustion boiler 1 may be provided with the 2nd atmospheric release part 120 in the upstream of a burner part. The second atmosphere opening portion 120 includes a flow path switching valve V14 disposed downstream of the frame arrester 50 in the hydrogen supply line L100, a downstream side of the frame arrester 50, and an upstream side of the flow path switching valve V14. An atmosphere release line L400 connected to the hydrogen supply line L100 and a second atmosphere release valve V15 as an atmosphere release valve disposed on the atmosphere release line L400 and opening and closing the atmosphere release line L400 are provided.
The second atmosphere opening unit 120 starts the blower 30 and does not ventilate the inside of the can body 10, and the inert gas G2 and the gas purged by the inert gas G2 (hydrogen gas G1, air, or a mixture thereof) Gas) can be released into the atmosphere.

The flow path switching valve V14 is configured by an electromagnetic valve, and opens and closes a gas flow path that flows through the hydrogen supply line L100 and flows to the burner 20 side, whereby the gas flow path is on the burner 20 side or the atmosphere release line L400 side. Switch to.
The atmosphere open line L400 is a line capable of releasing gas from the hydrogen supply line L100 to the atmosphere. The atmosphere open line L400 is a line that can release, for example, an inert gas G2 and a hydrogen gas G1 purged by the inert gas G2 into the atmosphere.
The second atmosphere release valve V15 is configured by an electromagnetic valve, and opens and closes the atmosphere release line L400.

Next, operations using the flow path switching valve V14, the atmosphere release line L400, and the second atmosphere release valve V15 will be described.
In this case, the shutoff valve upstream purge control unit 44 closes the flow path switching valve V14 (opens during boiler operation) and opens the second atmosphere release valve V15. Thereby, the gas (hydrogen gas, air, or a mixed gas thereof) staying in the hydrogen supply line L100 and the purging inert gas G2 can be discharged from the atmosphere open line L400 to the atmosphere without going through the can 10. . Accordingly, purging of the hydrogen supply line L100 (for example, the first supply valves V31 and V32 and the second supply valve V33 are opened, the first cutoff valve V11 and the second cutoff valve V12 are opened, and the fuel main valve V13 is used). Since the downstream hydrogen supply line L100 can be purged), the hydrogen supply line L100 can be purged without driving the blower 30.

  In this modification, the discharge destination of the gas purged by the inert gas G2 is switched to the burner 20 side or the atmosphere release line L400 side using the flow path switching valve V14 and the second atmosphere release valve V15. Not limited to this. That is, a three-way valve may be disposed at the connection portion between the hydrogen supply line L100 and the atmosphere release line L400, and the purged gas flow path may be switched by controlling the three-way valve by the shutoff valve upstream purge control unit 44.

DESCRIPTION OF SYMBOLS 1,1A Hydrogen combustion boiler 10 Can body 20 Burner 40, 40A Control part 41 Post purge control part 42 Pre purge control part 43 Abnormality detection part 44 Shutoff valve upstream purge control part 50 Flame arrester 60 Supply source 70 Orifice 80 Pressure detection part L100 Hydrogen Supply line L200 Purge line L250 Branch purge line L400 Atmospheric release line G1 Hydrogen gas G2 Inert gas V11 First shutoff valve (shutoff valve)
V12 2nd cutoff valve V13 Fuel source valve V14 Flow path switching valve V15 2nd atmosphere release valve (atmosphere release valve)
V31, V32 first supply valve

Claims (12)

With a burner,
A hydrogen supply line connected to the burner for supplying hydrogen gas to the burner;
A shutoff valve disposed in the hydrogen supply line and opening and closing a flow path of the hydrogen supply line;
A purge line connected to the vicinity of the shutoff valve on the downstream side of the shutoff valve, and supplying an inert gas to the hydrogen supply line;
A first supply valve that is disposed in the purge line and adjusts the supply amount of the inert gas;
A control unit for controlling opening and closing of the shutoff valve and the first supply valve,
The controller is
Closing the shut-off valve when stopping combustion of hydrogen gas in the burner,
A hydrogen combustion boiler comprising a post-purge control unit that opens the first supply valve only when the shut-off valve is closed. A can body,
The burner is disposed on the upper end surface of the can body,
The hydrogen supply line is connected to the burner from above the burner,
The hydrogen combustion boiler according to claim 1, wherein the purge line supplies an inert gas lighter than oxygen.   The said post purge control part controls opening and closing of a said 1st supply valve so that an inert gas more than 4 times the volume of the said hydrogen supply line from the said burner to the said cutoff valve may be supplied. 2. The hydrogen combustion boiler according to 2. The controller is
Before starting combustion of hydrogen gas by the burner, the first supply valve is opened for a predetermined time to supply inert gas from the purge line, and then the first supply valve is closed, and the first supply valve is closed. A pre-purge control unit that opens the shutoff valve after being
4. The hydrogen combustion boiler according to claim 1, wherein the pre-purge control unit allows the first supply valve to be opened only when the shut-off valve is closed. 5.   The said pre-purge control part controls opening and closing of a said 1st supply valve so that an inert gas more than 4 times the volume of the said hydrogen supply line between the said burner and the said cutoff valve may be supplied. Hydrogen fired boiler. The controller is
An abnormality detector for closing the shut-off valve when an abnormality in combustion of hydrogen gas in the burner is detected;
The hydrogen combustion boiler according to claim 4 or 5, wherein control by the pre-purge control unit is performed when combustion of hydrogen gas is started after the shutoff valve is closed by the abnormality detection unit. Further comprising an orifice disposed in the purge line;
The pressure of the inert gas downstream of the orifice in the purge line is set lower than the pressure of hydrogen gas supplied downstream of the shut-off valve in the hydrogen supply line in the minimum combustion state of the burner. Item 7. The hydrogen combustion boiler according to any one of Items 1 to 6.   The pressure of the inert gas upstream of the orifice in the purge line is set higher than the pressure of hydrogen gas supplied downstream of the shutoff valve in the hydrogen supply line in the maximum combustion state of the burner. Item 8. The hydrogen combustion boiler according to Item 7. A pressure detector disposed in the purge line for detecting the pressure of the inert gas;
The hydrogen combustion according to any one of claims 1 to 8, wherein the control unit stops combustion of hydrogen gas by the burner when the pressure of the inert gas detected by the pressure detection unit falls below a predetermined value. boiler. The hydrogen supply line connected to the hydrogen combustion boiler is provided with a fuel valve on the upstream side of the hydrogen combustion boiler,
A branch purge line branched from the purge line and connected to the hydrogen supply line in the vicinity of the downstream side of the fuel main valve;
A second supply valve disposed in the branch purge line and opening and closing the branch purge line;
Further comprising
The control unit, when purging with an inert gas between the fuel main valve and the shut-off valve, a shut-off valve upstream purge control that allows the hydrogen supply line to be purged only when the fuel main valve is closed The hydrogen combustion boiler according to claim 1, further comprising a section. A flow path switching valve disposed downstream of a connection position with the purge line in the hydrogen supply line; a downstream side of a connection position between the hydrogen supply line and the purge line; and a flow path switching valve. An open air line connected to the upstream hydrogen supply line, and an open air valve disposed in the open air line to open and close the open air line,
The hydrogen combustion boiler according to claim 10, wherein the shutoff valve upstream purge control unit purges the hydrogen supply line by closing the flow path switching valve and opening the atmosphere release valve.   The hydrogen combustion boiler according to any one of claims 1 to 11, further comprising a flame arrester disposed downstream of a connection position with the purge line in the hydrogen supply line.

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