JPH0828805A - Apparatus and method for supplying water to boiler - Google Patents

Abstract

PURPOSE:To extend the pressure control range of a motor-driven feed water pump and cover the pressure control range of a booster pump by controlling motors of A-system and B-system in such a manner that the discharge pressure of motor driven feed water pumps of the A-system and B-system respectively reaches specified pressures. CONSTITUTION:An A-system electric motor 1a is controlled by an A-system VVVF control apparatus 18a in such a manner that the discharge pressure of an A-system electric motor driven feed water pump 2a becomes equal to a suction pressure required for driving an A-system turbine driven feed water pump 4. A B-system electric motor 1b is controlled by a B-system VVVF control apparatus 18b in such a manner that the discharge pressure of a B-system electric motor driven feed water pump 2b becomes equal to a suction pressure required for driving a B-system turbine driven feed water pump 6. After then, the A-system turbine driven feed water pump 4 and the B-system turbine driven feed water pump 6 are driven and controlled by main steam fed to the A-system VVVF control apparatus 18a and the B-system VVVF control apparatus 18b by a boiler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply controller for controlling water supply to a boiler in a thermal power plant.

[0002]

2. Description of the Related Art When starting a thermal power plant, it is necessary to supply necessary water to a boiler. The water supply device for this boiler is generally configured as shown in FIG.
That is, an electric motor driven water feed pump 2 (hereinafter referred to as M-BFP2) driven by the electric motor 1 and an A system turbine 3 (A / BFP-T) connected in parallel to the electric motor driven water feed pump 2.
3) A-system turbine drive feed water pump 4 (hereinafter referred to as A-T-BFP4) and B-system turbine 5 (B-BFP-)
B system turbine drive feed water pump 6 (hereinafter referred to as B.T-BFP6) driven by T5), and these M-BFP2, A.T.
-BFP4, B-T-BFP6, booster pump 7, inlet valve 8 and outlet valve 9 connected in series, and these MB
The bypass valve 10 is connected in parallel to the FP2, the A-T-BFP4, and the B-T-BFP6.

In FIG. 6, the water supply to the boiler at the time of plant startup is supplied from the deaerator as low-pressure feed water through the deaerator outlet pipe 10 to each water supply pump. This low pressure water supply
By starting the booster pump 7m for M-BFP,
It is pushed up to the suction pressure required for FP2. The supply water of this pressure becomes high-pressure supply water when the M-BFP 2 is started up and is supplied to the high-pressure supply water heater and the boiler through the water supply pump outlet pipe 12.

When the plant is started and operated, the main steam from the boiler or steam turbine becomes stable, and part of it is
Extract as vapor of the pressure and temperature required for BFP-T3 and B.BFP-T5. As a result, the steam for driving the A / BFP-T3 and B / BFP-T5 from the boiler or the steam turbine is transferred to the A / BFP-T steam inlet pipe 13 and the B / B steam pipe.
A ・ B FP-T3 and B through the FP-T steam inlet pipe 14
-Supplied to BFP-T5. A ・ BFP-T3 and B
・ From the rotation increase of BFP-T5, each A ・ T-B
When the FP4 and BT-BFP6 become operable, the low-pressure water supply from the deaerator downcomer 11 passes through the BT-BFP booster pump 7a and the BT-BFP booster pump 7b, and the ATT- It is pushed up to the suction pressure required for BFP4 and B-T-BFP6. The water supply of the pressure that has been respectively raised is AT-BFP4 and AT-BFP6.
Sends high pressure feed water to the feed pump outlet pipe 12.

When the high-pressure feed water flow rate from the feed water pump outlet pipe 12 to the high-pressure feed water heater and the boiler is secured, M-BFP
2 and the M-BFP booster pump 7m are stopped. M
As shown in FIG. 7, the BFP2 is controlled by sending a feedwater flow rate request signal from the automatic plant controller 15 (hereinafter referred to as APC15) to the torque converter 16 to control the feedwater flow rate. As described above, in the normal operation of the plant, the water supply is performed by the A-T-BFP4 and the B-T-BFP6, and the M-BFP2 is used for backup and startup.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
FP2 is the water supply flow rate control by the torque converter 15 which receives the water supply flow rate request signal from the APC 40 as shown in FIG.
Since M-BFP2 is the rated speed, as shown in FIG.
-Pressure control is performed within the pressure control range Z2 of BFP2. In addition, M-BFP2, A-T-BFP4 and B-T-BF
In order to secure the suction pressure of P6, the booster pump 7m for M-BFP and the booster pump 7 for AT-BFP, respectively.
A and the booster pump 7b for AT-BFP were required.

An object of the present invention is to provide a water supply apparatus and a control method thereof which can cover the pressure control range of the booster pump by expanding the pressure control range of the M-BFP.

[0008]

According to a first aspect of the present invention, there is provided a boiler water supply apparatus, wherein an electric motor driven water supply pump for supplying water to the boiler when starting the boiler and a main steam having a predetermined temperature and pressure are established from the boiler. Then, it is a boiler water supply apparatus having A-system and B-system turbine-driven water supply pumps which are started by the main steam and supply water to the boiler, and which are provided in series on the suction side of the A-system turbine-driven water supply pump. System electric motor driven water supply pump, B system electric motor driven water supply pump provided in series on the suction side of B system turbine driven water supply pump,
An A-system VVVF control device for controlling the number of revolutions of an electric motor for driving a system electric motor driven water supply pump with a variable voltage variable frequency;
B-system VVVF control device for controlling the rotation speed of the electric motor for driving the B-system electric motor driven water supply pump with a variable voltage and variable frequency, an A-system bypass valve provided by bypassing the A-system turbine driven water supply pump, and a B-system turbine A B-system bypass valve provided by bypassing the drive water supply pump, and a connection valve that connects the discharge side of the A-system electric motor drive water supply pump and the discharge side of the B-system electric motor drive water supply pump are provided.

A second aspect of the present invention is a control method for controlling the boiler water supply device according to the first aspect, in which the connection valve is closed and the A-system bypass valve and the B-system bypass valve are opened at the time of starting the boiler to supply water to the boiler. Based on the flow rate request signal, the A system electric motor driven water supply pump is controlled so that the discharge pressure becomes a predetermined pressure.
The system VVVF control device drives and controls the A system electric motor driven water feed pump, and the B system VVVF controller drives and controls the B system electric motor driven water feed pump so that the discharge pressure of the B system electric motor driven water feed pump becomes a predetermined pressure. When main steam with a predetermined temperature and pressure is established from the boiler, the A system bypass valve and the B system bypass valve are closed, and the discharge pressure of the A system electric motor driven feed pump becomes the suction pressure required to drive the A system turbine driven feed water pump. The A system VVVF control device drives and controls the A system electric motor driven feed water pump so that the discharge pressure of the B system electric motor driven feed water pump becomes the suction pressure required to drive the B system turbine driven feed water pump. The control device drives and controls the B system electric motor driven water supply pump, and based on the boiler water supply flow rate request signal, the A system turbine driven water supply pump and the B system turbine driven water supply pump. Controlling the driving of the flop in main steam from the boiler.

According to a third aspect of the present invention, in the control method according to the second aspect, when the A-system turbine drive feed water pump fails, the A-system bypass valve is opened, and the A-system VVVF is supplied based on the feed water flow rate demand signal to the boiler. The control unit drives and controls the system A electric motor driven water supply pump.

According to a fourth aspect of the present invention, in the control method according to the second aspect, the connection valve is opened when the A system electric motor driven feed water pump fails, and the discharge pressure of the B type electric motor driven feed water pump is A.
The B system VVVF controller drives and controls the B system electric motor driven water supply pump so that the suction pressures required to drive both the system turbine driven water supply pump and the B system turbine driven water supply pump are obtained.

A boiler water supply apparatus according to a fifth aspect of the present invention supplies an electric motor driven water supply pump for supplying water to the boiler when the boiler is started up, and when main steam of a predetermined temperature and pressure is established from the boiler, the main steam is started to supply water to the boiler. Supply A system and B
A boiler water supply apparatus having a system turbine-driven water supply pump, and an electric motor-driven water supply pump provided in series on the suction side of the A-system turbine-driven water supply pump and the B-system turbine-driven water supply pump that are provided in parallel. A VVVF control device for controlling the rotation speed of an electric motor for driving the electric motor driven water supply pump with a variable voltage variable frequency; and a bypass valve provided by bypassing the A system turbine driven water supply pump and the B system turbine driven water supply pump. I have it.

A sixth aspect of the present invention is a control method for controlling the boiler water supply apparatus according to the fifth aspect, wherein the bypass valve is opened at the time of starting the boiler, and the electric motor driven water supply pump is opened based on the water supply flow rate request signal of the boiler. The VVVF controller drives and controls the electric motor driven feed water pump so that the discharge pressure of the electric motor becomes a predetermined pressure, and when main steam of a predetermined temperature and pressure is established from the boiler, the bypass valve is closed, and the discharge pressure of the electric motor driven feed water pump. Is controlled by the VVVF controller so that the suction pressure required to drive both the A-system turbine-driven water supply pump and the B-system electric-motor driven water supply pump is controlled by the VVVF controller, and A is supplied based on the boiler water supply flow rate request signal. The system turbine driven feed water pump and the B system turbine driven feed water pump are drive-controlled by the main steam from the boiler.

According to another aspect of the present invention, there is provided a boiler water supply apparatus, wherein an electric motor driven water supply pump for supplying water to the boiler at the time of starting the boiler and main steam having a predetermined temperature and pressure established from the boiler are started by the main steam to supply water to the boiler. Supply A system and B
It is a boiler water supply apparatus in which a turbine-driven feed water pump of a system is connected in parallel, and is provided in series on the suction side of the A-system turbine drive feed water pump and in series with the suction side of the B-system turbine drive feed water pump. It is provided with a B-system booster pump provided in series and a VVVF control device that controls the rotation speed of the electric motor that drives the electric motor drive water supply pump at a variable voltage variable frequency.

An eighth aspect of the present invention is a control method for controlling the boiler water supply device according to the seventh aspect, wherein the discharge pressure of the electric motor driven water supply pump is predetermined when the boiler is started based on the water supply flow rate request signal of the boiler. When the VVVF control device drives and controls the electric motor drive water feed pump so that the pressure becomes the pressure, and when main steam of a predetermined temperature and pressure is established from the boiler, the discharge pressure of the A system booster pump drives the A system turbine drive water feed pump. Drive control of the A system booster pump so that the suction pressure required for the B system booster pump is adjusted so that the discharge pressure of the B system booster pump becomes the suction pressure required to drive the B system turbine driven water supply pump. Drive control is performed, and the A system turbine drive water supply pump and the B system turbine drive water supply pump are driven and controlled by the main steam from the boiler based on the boiler feed water flow rate demand signal. To.

[0016]

In the boiler water supply apparatus according to the first aspect of the present invention, the connection valve is closed and the A system bypass valve and the B system bypass valve are opened at the time of starting the boiler so that the discharge pressure of the A system electric motor driven water supply pump becomes a predetermined pressure. A system VVVF controller so that
The system electric motor drive water supply pump is drive-controlled, and similarly, the system B electric motor drive water supply pump is drive-controlled by the system B VVVF controller so that the discharge pressure of the system B electric motor drive water supply pump becomes a predetermined pressure. Then, when main steam of a predetermined temperature and pressure is established from the boiler, the A system bypass valve and the B system bypass valve are closed, and the discharge pressure of the A system electric motor driven water feed pump is the suction required to drive the A system turbine driven water feed pump. The A system VVVF control device drives and controls the A system electric motor driven water feed pump so that the pressure becomes the same, and similarly the discharge pressure of the B system electric motor driven water feed pump becomes the suction pressure required to drive the B system turbine driven water feed pump. In addition to controlling the drive of the B system electric motor driven water supply pump by the B system VVVF control device,
Based on the feed water flow rate request signal of the boiler, the A system turbine driven feed water pump and the B system turbine driven feed water pump are drive-controlled by the main steam from the boiler.

When the A-system turbine drive feed water pump fails, the A-system bypass valve is opened, and the A-system VVVF control device drives and controls the A-system electric motor drive feed water pump based on the feed water flow rate request signal to the boiler. . Further, when the A system electric motor driven water supply pump fails, the connection valve is opened so that the discharge pressure of the B system electric motor driven water supply pump is the suction pressure required to drive both the A system turbine driven water supply pump and the B system turbine driven water supply pump. The B system VVVF control device drives and controls the B system electric motor driven water supply pump.

In the boiler water supply apparatus of the fifth aspect, the bypass valve is opened at the time of starting the boiler, and the electric motor drive water supply pump is drive-controlled by the VVVF controller so that the discharge pressure of the electric motor drive water supply pump becomes a predetermined pressure. When main steam with a predetermined temperature and pressure is established from the boiler, the bypass valve is closed, and the discharge pressure of the electric motor driven water supply pump becomes the suction pressure required to drive both the A system turbine driven water supply pump and the B system electric motor driven water supply pump. As described above, the VVVF control device drives and controls the electric motor driven water supply pump, and drives and controls the A system turbine driven water supply pump and the B system turbine driven water supply pump by the main steam from the boiler based on the boiler water supply flow rate request signal.

According to another aspect of the boiler water supply device of the present invention, the VVVF control device controls the rotation speed of the electric motor for driving the electric motor driven water supply pump at a variable voltage variable frequency when the boiler is started to supply the water supply to the boiler. When the main steam having the temperature and pressure is established, the A system and B system booster pumps provided on the suction side of the A system and B system turbine drive feed water pumps are driven, and the main steam supplies the feed water to the boiler. Start the B system turbine drive water supply pump.

[0020]

Embodiments of the present invention will be described below. FIG. 1 is a block diagram of the first embodiment of the present invention. A system electric motor driven water supply pump 2a is provided on the suction side of the A system turbine driven water supply pump 4.
Are provided in series, and the B system electric motor driven water supply pump 6 is provided in series on the suction side of the B system turbine driven water supply pump 5. The discharge side of the A system turbine driven water supply pump 4 is connected to the water supply pump outlet pipe 12 via the outlet valve 9a, and the suction side of the A system electric motor driven water supply pump 2a is connected to the deaerator precipitation pipe via the inlet valve 8a. Connected to 11. Similarly, the discharge side of the A system turbine driven water supply pump 6 is connected to the water supply pump outlet pipe 12 via the outlet valve 9b, and the suction side of the B system electric motor driven water supply pump 2b is connected to the deaerator precipitation pipe via the inlet valve 8b. Connected to 11.

Next, the A system electric motor driven water supply pump 2a is
Driven by the system electric motor 1a, the A system electric motor 1a is an A system V
It is controlled by the VVF controller 18a. That is, A system VV
The VF control device 1a controls the rotation speed of the A-system electric motor 1a with a variable voltage variable frequency. Similarly, the B system electric motor drive water supply pump 2b is driven by the B system electric motor 1b.
b is controlled by the B system VVVF controller 18b, and the B system VV
The VF control device 1b controls the rotation speed of the B-system electric motor 1b with a variable voltage variable frequency.

On the other hand, an A system bypass valve 10a is provided to bypass the A system turbine drive feed water pump 4, and a B system bypass valve 10b is provided to bypass the B system turbine drive feed water pump 6.
Is provided. In addition, the A system electric motor driven water supply pump 2
The connection valve 17 connects the discharge side of a and the discharge side of the B-system electric motor drive feed pump 2b.

As shown in FIG. 2, the VVVF controller 18 is connected to the electric motor 1 of the M-BFP 2 of both the A system and the B system of FIG. 1, and the feed water flow rate request signal is VVVF controlled from the plant automatic operation device 15 (APC15). Input to device 18. As shown in FIG. 1, the A-system and B-system M-BFPs 2a and 2b are
It is installed on the upstream side of T-BFP4, 6 of A system and B system.

Receiving the feed water flow rate request signal from the APC 22, the A-system and B-system VVVF controllers 18a and 18b change the rotational speeds of the electric motors 1a and 1b of the A-M-BFP2a and the B-M-BFP2b, respectively. Supply high pressure water supply.

Further, as shown in FIG. 3, A-M-BFP2
a and B / M-BFP2b are A / VVVF controller 18a
Since the B / VVVF control device 18b can control the rotation speed of the M-BFP2 motor, the VVVF M-BFP can be controlled.
It becomes the pressure control range Z1 of 2, and the conventional MB
The control range is wider than the FP pressure control range Z2, and BF
It also includes the outlet pressure P3 of the booster pump for P.

As a result, A.M-BFP2a and B.
The M-BFP2b can be used similarly to a booster pump for BFP. Next, a method for controlling the boiler water supply device shown in FIG. 1 will be described. The connection valve 17 is closed when the boiler is activated. Then, the A-system bypass valve 10a and the B-system bypass valve 10
Open b. In addition, A system inlet valve 8a and B system inlet valve 8
Open b. In this state, the boiler feed water flow rate request signal is given from the APC 15 to the A system VVVF controller 18a and the B system VVVF controller 18b. The A system VVVF control device 18a and the B system VVVF control device 18b respectively use the A system electric motor driven water supply pump 2a based on the feed water flow rate request signal of the boiler.
Also, it drives and controls the B system electric motor driven water supply pump 2b.

That is, the A system VVVF control device 18a controls the A system electric motor 1a so that the discharge pressure of the A system electric motor drive feed pump 2a becomes a predetermined pressure, and the B system VVVF control device 18b controls the B system electric motor drive water supply. The B system electric motor 1b is controlled so that the discharge pressure of the pump 2b becomes a predetermined pressure.

When the main steam having a predetermined temperature and pressure is established from the boiler, the A system bypass valve 10a and the B system bypass valve 10b are closed. Further, the A system VVVF controller controls the A system electric motor 1a so that the discharge pressure of the A system electric motor driven water supply pump 2a becomes the suction pressure required for driving the A system turbine driven water supply pump 4. Similarly, the B system VVV is adjusted so that the discharge pressure of the B system electric motor driven water supply pump 2b becomes the suction pressure required to drive the B system turbine driven water supply pump 6.
The F control device 18b controls the B system electric motor 1b. In this state, thereafter, the A system turbine drive feed water pump 4 and the B system turbine drive feed water pump 6 are driven and controlled by the main steam from the boiler based on the feed water flow rate request signal of the boiler.

That is, when the plant is started, AV
The VVF control device 18a or the B / VVVF control device 18b sets the electric motor 1a or the electric motor 1b to the rated rotation speed or the maximum rotation speed, and the A / M-BFP2a or the B / M-BFP2b requires the boiler to supply low pressure water from the deaerator. A high pressure water supply,
It is supplied to the BFP outlet pipe 12 via the T-BFP bypass valve 10a or the B-T-BFP bypass valve 10b.

After that, when the main steam pressure and temperature of the steam turbine become stable, the operation is switched to normal operation. In this case, AM
-BFP2a and B-M-BFP2b are operated at a low load by the A-VVVF controller 18a or the B-VVVF controller 18b, and the low-pressure feed water is A-T-BFP4 and B-T-BFP.
Set the suction pressure required for 6 and the AT-BFP bypass valve 10
a and B-T-BFP bypass valve 10b is closed, A-T-
Supply to BFP4 and B-T-BFP6.

A part of the main steam is sent to A.BFP-T3 and B.BFP-T5, and A.T-BFP4 and B.T.
-Operate the BFP6 to obtain the high pressure water supply required for the supplied water supply boiler.

As a backup of loss of function, A
・ When T-BFP4 or B ・ T-BFP6 fails and A ・ M
An example is shown in which -BFP2a or BT-BFP2b fails.

When A.T-BFP4 or B.T-BFP6 fails, A.T-BFP4 or B.T-BFP6 is set to A.
-Bypassing through the T-BFP bypass valve 10a or the B-T-BFP bypass valve 10b, the output of A-M-BFP2a or B-M-BFP2b is A-VVVF control device 18a.
Or raise it with the B / VVVF control device 18b, then use the A / T-BFP
4 or B-M-BFP6 is backed up.

Also, A.M-BFP2a or B.M-B
If the FP2b fails, open the connection valve 17 and press AT
The output of the B.M-BFP2b or the A.M-BFP2a is controlled by the A.VVVF control device 18a or the B.VVVF control device 18 so as to secure the suction pressure of the BFP4 and the B.T-BFP6.
Adjust with b, A ・ M-BFP1a or B ・ M-BFP2
Backup a.

As described above, in this embodiment, M is VVVF.
-By controlling the BFP, the BF required by the conventional technology
The booster pump for P is not needed, the entire water supply pump system is downsized, and the reliability is improved by backing up the loss of function of the equipment.

Next, a second embodiment of the present invention is shown in FIG. As shown in FIG. 4, one M-BFP is removed from that in FIG. 1, and one M-BFP2 to two A-T-BFs.
Connected to P4 and B-T-BFP6, M
-For the BFP2, the VVVF controller is used as in the embodiment of FIG.
18 is attached.

As in the embodiment of FIG. 1, the M-BFP2 secures the suction pressure of A.T-BFP4 and B.T-BFP6 by controlling the rotation speed of the M-BFP2 by the VVVF controller 18.

The effect is to provide a water supply device which does not require a booster pump as compared with the prior art, and can realize downsizing of the water supply pump system. Further, FIG. 5 shows a third embodiment of the present invention. As shown in FIG. 5, V is applied to M-BFP2 as compared with the conventional example.
The VVF controller 18 is attached and the booster pump for M-BFP is eliminated. As the VVVF control device 18 has expanded the pressure control range of the M-BFP 2 as shown in FIG. 3 similarly to the above, it becomes possible to provide a water supply control device that does not require one M-BFP booster pump.

[0039]

As described above, according to the present invention, the BF
A BFP booster pump for securing the suction pressure of P is not necessarily required, and a water supply apparatus and a control method therefor that can realize downsizing of the water supply pump system can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a driving portion of an electric motor driven pump of the present invention.

FIG. 3 is an explanatory diagram of characteristics of the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a third embodiment of the present invention.

FIG. 6 is a block diagram of a conventional example

FIG. 7 is an explanatory diagram of a drive portion of a conventional electric motor drive pump.

FIG. 8 is an explanatory diagram of characteristics of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric motor 2 ... Electric motor drive pump 3 ... A system turbine 4 ... A system turbine drive feed water pump 5 ... B system turbine 6 ... B system turbine drive feed water pump 7 ... Booster pump 8 ... Inlet valve 9 ... Outlet valve 10 ... Bypass valve 11 ... Deaerator downfall pipe 12 ... Water supply pump outlet pipe 13, 14 ... Steam inlet pipe 15 ... Automatic plant control device 16 ... Torque converter
17 ... Connection valve 18 ... VVVF controller

Claims (8)

[Claims] 1. A motor-driven water feed pump that supplies water to the boiler when the boiler is started up, and an A system that is started by the main steam when the main steam of a predetermined temperature and pressure is established from the boiler and supplies the water to the boiler. And a boiler water supply apparatus having a B-system turbine drive water supply pump,
A system electric motor driven feed water pump provided in series on the suction side of the system turbine driven feed water pump, B type electric motor driven feed water pump provided in series on the suction side of the B type turbine driven feed water pump, and said A system electric motor A system V that controls the rotation speed of the electric motor that drives the drive water supply pump with a variable voltage and variable frequency
A VVF control device, a B system VVVF control device that controls the number of revolutions of an electric motor that drives the B system electric motor driven water supply pump with a variable voltage variable frequency, and an A system provided by bypassing the A system turbine driven water supply pump. A bypass valve, a B-system bypass valve that is provided to bypass the B-system turbine drive feed water pump, a connection that connects the discharge side of the A-system electric motor drive feed water pump and the discharge side of the B-system electric motor drive feed water pump A boiler water supply device comprising a valve. 2. When the boiler is started, the connection valve is closed, and the A system bypass valve and the B system bypass valve are opened,
Based on the feed water flow rate request signal of the boiler, the A system VVVF control device drives and controls the A system electric motor drive water supply pump so that the discharge pressure of the A system electric motor drive water supply pump becomes a predetermined pressure. The B system VVVF controller drives and controls the B system electric motor driven water supply pump so that the discharge pressure of the system electric motor driven water supply pump becomes a predetermined pressure.
When main steam having a predetermined temperature and pressure is established from the boiler, the A-system bypass valve and the B-system bypass valve are closed, and the discharge pressure of the A-system electric motor driven water supply pump is required to drive the A-system turbine driven water supply pump. The A-system VVVF control device to drive and control the A-system electric motor drive feed water pump so that the suction pressure becomes a constant suction pressure, and the discharge pressure of the B-system electric motor drive feed water pump is the suction required to drive the B-system turbine drive feed water pump. The B system VVVF control device drives and controls the B system electric motor driven feed pump so that the pressure becomes a pressure, and the A system turbine driven feed pump and the B system turbine driven feed pump are controlled based on a feed water flow rate request signal of the boiler. The control method of the boiler water supply device according to claim 1, wherein the main steam from the boiler is used for drive control. 3. When the A-system turbine drive water supply pump fails, the A-system bypass valve is opened, and the A-system VVVF controller controls the A-system electric motor drive water supply based on a supply water flow rate request signal to the boiler. The control method according to claim 2, wherein the pump is drive-controlled. 4. When the A-system electric motor driven water feed pump fails, the connection valve is opened so that the discharge pressure of the B-system electric motor driven water feed pump is the same as that of the A-system turbine driven water feed pump and the B-system turbine driven water feed pump. 3. The control method according to claim 2, wherein the B-system VVVF control device drives and controls the B-system electric motor drive feed pump so that the suction pressures required for driving both of them are set. 5. A motor-driven water feed pump for supplying water to the boiler when the boiler is started up, and an A system for supplying water to the boiler when main steam having a predetermined temperature and pressure is established from the boiler. And a B-system turbine drive water supply pump, a motor-driven water supply system provided in series on the suction side of the A-system turbine drive water supply pump and the B-system turbine drive water supply pump that are provided in parallel. A pump, a VVVF control device for controlling the number of revolutions of an electric motor for driving the electric motor driven water supply pump with a variable voltage and a variable frequency, and a bypass for the A system turbine driven water supply pump and the B system turbine driven water supply pump. A boiler water supply device comprising a bypass valve. 6. The bypass valve is opened at the time of starting the boiler, and based on a feed water flow rate request signal of the boiler,
The electric motor drive water feed pump is drive-controlled by the VVVF control device so that the discharge pressure of the electric motor drive water feed pump becomes a predetermined pressure, and when the main steam having a predetermined temperature and pressure is established from the boiler, the bypass valve is opened. The VVVF control device closes the electric motor driven water supply pump so that the discharge pressure of the electric motor driven water supply pump becomes the suction pressure required to drive both the A system turbine driven water supply pump and the B system electric motor driven water supply pump. The drive control is performed, and the A system turbine drive feed water pump and the B system turbine drive feed water pump are drive-controlled by the main steam from the boiler based on a feed water flow rate request signal of the boiler. 5. The method for controlling the boiler water supply device according to 5. 7. An electric motor driven water supply pump for supplying water to the boiler when the boiler is started up, and an A system for starting the main steam when the main steam of a predetermined temperature and pressure is established from the boiler and supplying the water to the boiler. And a B-system turbine-driven feed water pump connected in parallel, in a boiler water supply apparatus, an A-system booster pump provided in series on the suction side of the A-system turbine drive feed water pump, and a suction of the B-system turbine drive feed water pump. A boiler water supply device comprising a B-system booster pump provided in series on the side, and a VVVF control device that controls the rotation speed of an electric motor that drives the electric motor drive water supply pump with a variable voltage variable frequency. 8. When the boiler is started, the VVVF control device drives and controls the electric motor driven water supply pump so that the discharge pressure of the electric motor driven water supply pump becomes a predetermined pressure based on a feed water flow rate request signal of the boiler. However, when the main steam having a predetermined temperature and pressure is established from the boiler, the discharge pressure of the booster pump of the A system is adjusted so that the discharge pressure of the A system booster pump becomes a suction pressure necessary for driving the A system turbine drive water supply pump. The booster pump is driven and controlled, and the booster pump of the B system is driven and controlled so that the discharge pressure of the booster pump of the B system becomes the suction pressure necessary for driving the turbine-driven feed water pump of the B system, and the feed water of the boiler is supplied. Based on the flow rate request signal, the A system turbine driven feed water pump and the B system turbine driven feed water pump are drive-controlled by the main steam from the boiler. The method for controlling the boiler water supply device according to claim 7, wherein the method is as described above.