JP4990640B2 - Cooling medium circulation supply system and cooling method for equipment to be cooled - Google Patents

Description

  The present invention relates to an improvement of a cooling medium circulation supply system for cooling a cooling target device such as a BOG compressor attached to a power plant, a factory, and other facilities equipped with an LNG tank.

Power plants, factories, and other facilities equipped with LNG tanks for storing LNG are equipped with BOG compressors, using liquefied natural gas (LNG) as fuel. A BOG compressor is a device that takes out the boil-off gas (BOG) that has naturally evaporated from the LNG in the LNG tank, pressurizes it, and sends it to the next process such as a combustor. The BOG compressor keeps the gas pressure in the LNG tank constant. (Patent Documents 1 and 2).
Since the BOG compressor generates heat when boosting the LNG, it is necessary to ensure stable operation and safety by always cooling the heat generation portion below a certain allowable temperature. For this reason, as shown in the cooling water system diagram of FIG. 4, a cooling water circulation system 100 for circulating and supplying cooling water to the BOG compressor 101 is provided.
The cooling water circulation system 100 includes a cooling water supply pipe 102 for supplying cooling water to the BOG compressor 101, a cooling water return pipe 103 for returning cooling water after cooling the BOG compressor 100, and a cooling water return. A cooling device 105 that cools the cooling water that has returned through the pipe 103 and then circulates and supplies the cooling water to the cooling water supply pipe 102 and a pump 106 are provided. As the cooling water, one to which a chemical is added in order to adjust the pH value or the like is used.

  When the cooling water circulation system 100 fails, for example, when the cooling water cannot be supplied to the BOG compressor 101 due to the operation stop of the cooling device 105 or the like, the LNG tank security problems such as the operation stop due to seizure of the BOG compressor. Therefore, backup water intake that always connects between the appropriate location of the cooling water supply pipe 102 and the industrial water (industrial water) pipe (industrial water system) 110 disposed at a location separated from the cooling water supply pipe. A pipe 115 is provided. The intake pipe 115 is provided with solenoid valves 116 and 117. The solenoid valves 107 and 108 are closed only in an emergency when the cooling water circulation system cannot be operated, the solenoid valves 116 and 117 are opened, and the intake pipe 115 is opened. The BOG compressor 101 is cooled by supplying industrial water to the cooling water supply pipe 102 via the. The industrial water after cooling the BOG compressor is drained from the drain pipe 104 connected to the appropriate place of the cooling water return pipe 103 to the outside (drainage groove or the like).

However, despite the fact that the cooling water circulation system does not stop frequently, backup water intake piping 115 and solenoid valves 107, 108, 116, 117 are always installed between the industrial water supply system. For this reason, there are problems that the material cost for the intake pipe and the management cost increase, and that it is necessary to always secure the installation space.
In addition, the electromagnetic valve 116 provided in the intake pipe 115 may not be able to completely close the intake pipe due to various reasons, for example, dust or the like being caught. In such a case, if piping or the like is always provided between the cooling water supply pipe 102 and the industrial water pipe 110, the industrial water leaks from the industrial water pipe 110 to the cooling water supply pipe 102. In addition, there is a risk of cooling water flowing out from the cooling water supply pipe 102.
Such a problem is not limited to the cooling water circulation system for the BOG compressor, but also in the cooling water circulation system for cooling the control air compressor that controls the air-driven on-off valves installed at various locations in the LNG power plant. Has also occurred.
Japanese Patent Laid-Open No. 11-351498 JP 2000-213697 A

  As described above, in power plants and factories equipped with LNG tanks, a cooling water circulation system is provided to prevent the BOG compressor and other equipment from being heated during operation, and the cooling water circulation system is suspended. In preparation for this, water intake piping and solenoid valves are always provided between the industrial water supply system (industrial water piping). However, since an emergency such as a shutdown of the cooling water circulation system occurs very rarely, if piping and solenoid valves are permanently installed between the industrial water supply system, there are problems such as increased costs and wasted installation space. Will occur. Also, if the cooling water circulation system and the industrial water supply system are always connected by water piping, leakage of industrial water or cooling water will occur if the solenoid valve placed in the water intake piping is not sufficiently tightened. There is also the problem of doing.

  The present invention has been made in view of the above, and in a facility such as a power plant or a factory equipped with an LNG tank, a cooling water circulation system for cooling a cooling target device such as a BOG compressor has been suspended. In preparation for the construction of a backup system that temporarily cools the equipment to be cooled with industrial water supplied from the industrial water supply system, water intake piping for supplying industrial water to the pipes constituting the cooling water circulation system A cooling medium circulation supply system capable of constructing a backup system capable of supplying industrial water (cooling medium) only in the event of an emergency without incurring problems such as increased costs due to permanent installation and increased installation space. The purpose is that.

In order to achieve the above object, a cooling medium circulation supply system according to the invention of claim 1 includes a cooling water supply pipe for supplying cooling water to a cooling target device, and cooling after cooling the cooling target device. A cooling water circulation system comprising: a cooling water return pipe for returning water; and a cooling device for cooling and supplying the cooling water returned from the cooling water return pipe to the cooling water supply pipe. An industrial water supply system that supplies industrial water to the cooling object using a part of the cooling water circulation system when the system is stopped. An intake pipe for receiving industrial water disposed at an appropriate place and an on / off valve for the intake pipe, an industrial water drainage pipe disposed at an appropriate position for the cooling water return pipe, and an on / off valve for the drain pipe, Craft A temporary connection pipe which detachably connects the industrial water pipe and the intake pipe constituting the water supply system, characterized by comprising a.
In the event of an emergency in which the cooling water circulation system that constantly cools the cooling target device due to permanent installation cannot function normally, measures have been conventionally taken to cool the target device using industrial water. However, in the past, since piping equipment for emergency situations with low occurrence frequency was permanently installed, there were problems in terms of cost and installation space. In the present invention, conventional problems can be solved at once by using a temporary connection pipe that can be connected without delay only when necessary.

The invention of claim 2 is characterized in that, in claim 1, the device to be cooled is a BOG compressor attached to an LNG tank.
According to a third aspect of the present invention, in the first or second aspect, the temporary connection pipe is a fire hydrant hose.
By using a flexible hose or the like as the temporary connection pipe, it is possible to select any optimum piping route.
The invention of claim 4 comprises any one of claims 1 to 3, comprising a spare cooling target device separately from the cooling target device, a spare cooling water circulation system separate from the cooling water circulation system, and The cooling water circulation system and the preliminary cooling water circulation system share the cooling device.

A cooling method of a cooling target device according to the invention of claim 5 is a cooling method of the cooling target device by industrial water using the cooling medium circulation supply system according to any one of claims 1 to 4, wherein Opening both the open / close valve of the intake pipe for receiving industrial water and the open / close valve of the drain pipe for industrial water drainage in a state where the industrial water pipe and the intake pipe are connected by a temporary connection pipe. The cooling target device is started to be cooled with industrial water.
The invention of claim 6 is the invention according to claim 5, wherein the step of stopping the operation of the cooling target device, the step of starting the preliminary cooling target device, the on-off valve of the intake pipe for receiving industrial water, and the industrial water A step of closing both the on-off valve of the drain pipe for drainage, a step of starting supply of cooling water to the equipment to be cooled via the standby cooling water circulation system that operates the cooling water circulation system when stopped , and Stopping the supply of the cooling medium to the device to be cooled, and each step is executed after the cooling water circulation system is restored.

A facility such as a power plant equipped with an LNG tank is equipped with a BOG compressor in order to keep the BOG pressure in the LNG tank constant. The BOG compressor is configured to be cooled by a cooling water circulation system so that the operation is not stopped due to heat generation.
When the cooling water circulation system is malfunctioning, pipes, solenoid valves, and interlocks are configured to supply industrial water at a location away from security needs to the BOG compressor as a substitute for cooling water. However, there has been a problem of cost increase and installation space increase due to permanent installation of piping only for emergency use.
The present invention is configured to construct a backup system capable of supplying industrial water (cooling medium) only when an emergency occurs.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is a schematic configuration diagram of a cooling medium circulation supply system according to an embodiment of the present invention.
The cooling water circulation system 1 performs cooling by circulating and supplying cooling water (cooling medium) to a BOG compressor (cooling target device) 2 attached to an LNG tank installed in an LNG power plant, for example. .
The cooling water circulation system 1 includes a cooling water supply pipe 5 for supplying cooling water to the BOG compressor 2, a cooling water return pipe 10 for returning cooling water after cooling the BOG compressor 2, and cooling water. A cooling device 15 that circulates and supplies the cooling water that has returned through the return pipe 10 to the cooling water supply pipe 5 after cooling is provided, and a pump 16. As the cooling water, one to which a chemical is added in order to adjust the pH value or the like is used.
An opening / closing valve 8 for opening / closing the cooling water supply pipe, a strainer 8a, an electromagnetic valve 9 and the like are arranged at appropriate positions of the cooling water supply pipe 5, and an opening / closing valve for opening / closing the cooling water return pipe at appropriate positions of the cooling water return pipe 10. 13 is arranged.

  When the cooling water circulation system 1 fails, for example, when the cooling water cannot be supplied to the BOG compressor 2 due to the operation stop of the cooling device 15 or the pump 16, the LNG (not shown) is stopped due to the operation stop due to seizure of the BOG compressor. Since a security problem occurs on the tank side, in the present invention, the industrial water (engineering water) pipe 31 (industrial water supply system) disposed at a proper place of the cooling water supply pipe 5 and a place separated from the cooling water circulation system 1 is used. 30) is temporarily connected by a temporary connecting pipe 35 to supply industrial water as a cooling medium to the BOG compressor to cool it. The industrial water supply system 30 including the industrial water pipe 31 is not a dedicated means for backing up the cooling water circulation system 1 but a permanent supply means for supplying industrial water to other facilities. Therefore, industrial water is not adjusted in pH value like cooling water.

The characteristic configuration of the cooling medium circulation supply system according to the present invention is that an intake pipe 6 for receiving industrial water and an on-off valve of the intake pipe are disposed at appropriate positions (on the downstream side of the on-off valve 8 and the strainer 8a) of the cooling water supply pipe 5. 7 and a configuration in which a drain pipe 11 for industrial water drainage and a drain pipe on / off valve 12 are arranged at an appropriate position (upstream of the on-off valve 13) of the cooling water return pipe 10, and further away from the cooling water circulation system 1. The industrial water pipe 31 installed at the position and the temporary connection pipe 35 detachably connected to the water intake pipe 6 are provided.
As the temporary connection pipe 35, for example, a foldable hose for a fire hydrant is used, and the connection parts provided at both ends of the fire hydrant hose and the connection parts provided respectively for the intake pipe 6 and the industrial water pipe 31 are manually attached and detached. It is configured to be freely connected. In this example, a delivery pipe 32 and an on-off valve 33 are provided at appropriate positions on the industrial water pipe 31, and one end of a temporary connection pipe 35 is detachably connected to the delivery pipe 32. The temporary connection pipe 35 is normally housed in a place suitable for storage, and is taken out from the housing place only in an emergency and used for connecting the water intake pipe 6 and the industrial water pipe 31. .

The emergency connection pipe 35 is connected to the water pipe 6 and the delivery pipe 32 only in an emergency when the cooling water circulation system 1 cannot be operated, and the on-off valves 8 and 13 are closed and the on-off valves 7 and 12 are opened. Thus, the industrial water is supplied to the cooling water supply pipe 5 via the temporary connection pipe 35 to cool the BOG compressor 2. In addition, the industrial water after cooling the BOG compressor is drained from the drain pipe 11 connected to the cooling water return pipe 10 to the outside (drainage groove or the like).
The temporary connection pipe 35 is not connected between the cooling water circulation system 1 and the industrial water supply system 30 at all times, and is connected between both systems only in an emergency, so that industrial water is always sent to the cooling water circulation system side. Leakage or conversely cooling water will not flow out to the industrial water supply system. In particular, since a solenoid valve is not permanently installed, water leakage due to poor closing of the solenoid valve does not occur.

Reference numeral 2A denotes a spare BOG compressor, and the spare BOG compressor 2A is provided with a spare cooling water circulation system 1A. The spare cooling water circulation system 1A includes a spare cooling water supply pipe 5A for supplying cooling water to the spare BOG compressor 2A, and a spare for returning the cooling water after cooling the spare BOG compressor 2A. Common cooling water return pipe 10A, auxiliary cooling water return pipe 10A, and cooling water that has returned via the auxiliary BOG compressor 2A are cooled and then supplied to the auxiliary cooling water supply pipe 5A. The cooling device 15 and the pump 16 to be used are provided. A preliminary on-off valve 8A for opening and closing the preliminary cooling water supply pipe and a strainer 8a are disposed at appropriate positions on the preliminary cooling water supply pipe 5A, and the preliminary cooling water return is disposed at appropriate positions on the preliminary cooling water return pipe 10A. A preliminary on-off valve 13A for opening and closing the pipe is disposed.
The spare BOG compressor 2A and the spare coolant circulation system 1A are permanently installed to operate when the BOG compressor 2 and the coolant circulation system 1 are stopped for maintenance.

Next, FIG. 2 is a flowchart showing a procedure for supplying industrial water in an emergency such as when the cooling water circulation system stops operating.
When the operation stop of the cooling water circulation system or the like occurs, the operation of the BOG compressor 2 as the cooling target device is stopped (step 1).
Next, the coolant inlet valve (open / close valve 8) is fully closed, and the coolant outlet valve (open / close valve 13) is fully closed (step 2).
In step 3, a fire hydrant hose (temporary connection pipe 35) is provided between the delivery pipe 32 provided with the industrial water backup inlet valve (open / close valve 33) and the intake pipe 6 provided with the cooling water backup inlet valve (open / close valve 7). In step 4, a fire hydrant hose is connected to the drain pipe 11 provided with the cooling water backup outlet valve 12, and its discharge end is fixed to the drain groove.
In step 5, the cooling water inlet valve 9 is set to a fully open locked state, and in step 6, both the industrial water backup inlet valve 33 and the cooling water backup outlet valve 12 are fully opened.
In step 7, the required amount of industrial water is secured by adjusting the open state of the cooling water backup inlet valve 7 as necessary.
In step 8, the BOG compressor 2 is started.

Next, FIG. 3 is a flowchart showing an operation procedure for restoring the BOG compressor, which is performed at the stage where the cooling water circulation system is restored after the supply of industrial water is started by the procedure shown in FIG. The recovery procedure is shown.
In step 11, the BOG compressor 2 is stopped, and then the spare BOG compressor 2 </ b> A is started to start compression of the BOG taken out from the LNG tank.
In step 12, the industrial water backup inlet valve 33 is fully closed. In step 13, both the cooling water backup inlet valve 7 and the outlet valve 12 are fully closed. As a result, industrial water is not supplied to the cooling water circulation system, and industrial water is not discharged into the drainage channel.

Next, at step 14, the cooling water source inlet valve 8 and the outlet valve 13 are fully opened. As a result, a circulation cycle in which the cooling water is supplied to the BOG compressor 2 via the cooling water supply pipe 5 and the cooling water returns to the cooling device 15 via the cooling water return pipe 10 is performed. . Thereafter, the BOG compressor 2 is set in a standby state as a spare.
In step 15, the cooling water inlet valve 9 is fully closed. The cooling water inlet valve 9 has a function of automatically opening when the corresponding BOG compressor 2 is started and automatically closing in a predetermined time (for example, 5 minutes) after the compressor is stopped.
After the operation for restoration is thus completed, the temporary connection pipe 35 is removed and stored.

  As described above, according to the present invention, since a backup posture capable of supplying industrial water (cooling medium) only in the event of an emergency situation is constructed, the cost increase due to permanent installation of piping only for emergency use, Without causing the problem of an increase in installation space, when the cooling water circulation system is malfunctioning, industrial water at a remote location can be supplied to the BOG compressor as a substitute for cooling water.

1 is a schematic configuration diagram of a cooling medium circulation supply system according to an embodiment of the present invention. The flowchart which shows the supply operation procedure of the industrial water at the time of emergency, such as when a cooling water circulation system stops operation. The flowchart which shows the operation procedure for restoring a BOG compressor. Explanatory drawing of a prior art example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Cooling water circulation system, 1A ... Preliminary cooling water circulation system, 2 ... BOG compressor, 2A ... Preliminary BOG compressor, 5 ... Cooling water supply pipe, 5A ... Preliminary cooling water supply pipe, 6 ... Intake pipe, 7 8 ... Open / close valve, 8A ... Preliminary open / close valve, 12 ... Open / close valve, 10 ... Cooling water return pipe, 10A ... Preliminary cooling water return pipe, 11 ... Drain pipe, 12 ... Open / close valve, 13 ... Open / close valve, 13A ...... Preliminary open / close valve, 15 ... cooling device, 16 ... pump, 30 ... industrial water supply system, 31 ... industrial water piping, 32 ... delivery pipe, 33 ... open / close valve, 35 ... temporary connection pipe.

Claims (6)

A cooling water supply pipe for supplying cooling water to the cooling target device, a cooling water return pipe for returning the cooling water after cooling the cooling target equipment, and the cooling water returned from the cooling water return pipe And a cooling device that circulates and supplies the cooling water to the cooling water supply pipe, and uses a part of the cooling water circulation system for the object to be cooled when the cooling water circulation system is stopped. An industrial water supply system for supplying industrial water, and a cooling medium circulation supply system comprising:
An intake pipe for receiving industrial water disposed at an appropriate position of the cooling water supply pipe, and an on-off valve of the intake pipe;
A drain pipe for industrial water drainage disposed at an appropriate position of the cooling water return pipe, and an on-off valve for the drain pipe;
A temporary connection pipe that detachably connects between the industrial water pipe and the intake pipe constituting the industrial water supply system;
A cooling medium circulation supply system comprising:   The cooling medium circulation supply system according to claim 1, wherein the cooling target device is a BOG compressor attached to an LNG tank.   The cooling medium circulation supply system according to claim 1, wherein the temporary connection pipe is a hose for a fire hydrant. In addition to the cooling target device, a preliminary cooling target device is provided,
In addition to the cooling water circulation system, a preliminary cooling water circulation system is provided,
The cooling medium circulation supply system according to any one of claims 1 to 3, wherein the cooling water circulation system and the auxiliary cooling water circulation system share the cooling device. A cooling method of equipment to be cooled by industrial water using the cooling medium circulation supply system according to any one of claims 1 to 4,
In the state where the industrial water pipe and the intake pipe are connected by the temporary connection pipe, both the open / close valve of the intake pipe for receiving industrial water and the open / close valve of the drain pipe for industrial water drainage are opened. Thus, the cooling target device starts cooling with industrial water. Stopping the operation of the device to be cooled;
Activating a preliminary cooling target device;
Closing both the on-off valve of the intake pipe for receiving industrial water and the on-off valve of the drain pipe for industrial water drainage;
Starting to supply cooling water to the auxiliary cooling target device via the auxiliary cooling water circulation system that operates the cooling water circulation system when stopped ;
Stopping the supply of the cooling medium to the device to be cooled, and
The method of cooling a cooling target device according to claim 5, wherein the steps are executed after the cooling water circulation system is restored.

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