JPH08303712A - Make-up water supplier - Google Patents

Abstract

PURPOSE: To provide a make-up water supplier, capable of preventing water hammer in a make-up water pipeline, which is accompanied by the starting of the make-up water pump, without motorizing the outlet valve of the make-up water pump. CONSTITUTION: In this make-up water supplier, introducing make-up water from a tank 1, reserving the make-up water, into a condenser 9 by a make-up water pipeline 7 through the outlet valve 6 of the make-up water pump, a hydraulic joint 4 is arranged between the make-up water pump 3 and a motor 5 for driving the make-up water pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a make-up water supply system for a steam turbine plant, and in particular, it prevents a water hammer caused by a pressure increase at the time of starting a make-up water pump, and is safe, economical and excellent in operability. The present invention relates to a makeup water supply device capable of providing plant equipment.

[0002]

2. Description of the Related Art Not only in a steam turbine plant, generally, a pump having a certain capacity or more is electrically operated at its outlet valve, and the outlet valve is automatically and gradually opened at the same time as the pump is started. The pressure rise is suppressed and the water hammer is prevented from occurring on the piping path.

[0003]

By the way, in recent highly-informed steam turbine plants, most of the automated equipment is operated and controlled by a control computer in the central operating room or a control device based on it. . However, electrifying the outlet valves of all pumps is not always a rational and economical facility. In other words, when the target equipment is far away from the central control room, the cables for power and control of the motorized valve are very long and the amount of cable is large, and this motorized valve is used at the plant construction stage and during operation and maintenance. The financial burden of installing the

In view of the above points, the present invention is to electrify an outlet valve of a makeup water pump arranged in a pipe path from a makeup water tank or a pure water tank to a condenser via a makeup water pump. It is an object of the present invention to provide a make-up water supply device that is safe, economical, and has excellent operability by preventing water hammer on the piping path due to start-up of the make-up water pump.

[0005]

In order to achieve the above object, in the present invention according to claim 1, a makeup water pipe is provided from a tank for storing makeup water through a makeup water pump and a makeup water pump outlet valve. A makeup water supply device for guiding makeup water to a condenser, wherein a makeup of a fluid is provided between a makeup water pump and an electric motor for driving the makeup water pump. However, in the present invention as set forth in claim 2, in place of the fluid coupling as set forth in claim 1, a rotation speed control device for gradually increasing the rotation speed at startup of the makeup water pump within a predetermined range is provided. In the present invention according to claim 3, the rotation speed control device according to claim 2 inputs the pressure in the makeup water pipe and increases the pressure. Caused water hammer Providing makeup water supply apparatus characterized by having a rotation speed increase speed determination device for reducing the rotational speed of the makeup water pump when it becomes out of the range are.

[0006]

According to the present invention, when the makeup water pump is started, the rotation speed of the electric motor reaches the rated rotation speed immediately, but since the fluid coupling is installed between the electric motor and the makeup water pump, The pump side speed gradually increases. Therefore, it is possible to prevent a water hammer caused by a rapid increase in pressure on the piping path.

According to the present invention of claim 2,
When the make-up water pump is started, the rotation speed of the electric motor itself is gradually increased by the control signal output from the rotation speed control device. Therefore, the same effect as in the case of the present invention according to claim 1 can be obtained.

Further, in the present invention as set forth in claim 3, since the increase in pressure in the makeup water pipe is suppressed to a predetermined value by the rotation speed increase speed determination device, the water hammer is prevented and the start-up time of the makeup water pump is prevented. Can be minimized, and water can be supplied more promptly when supplementary water is required on the side of the device that requires other supplementary water.

[0009]

Embodiments of the makeup water supply apparatus according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example in which the makeup water supply device according to the first embodiment of the present invention is applied to a steam turbine plant. In FIG. 1, makeup water 1 a stored in a pure water tank or makeup water tank 1 is supplied to a condenser 9 by a makeup water pipe 7. The flow rate of make-up water to the condenser 9 is controlled by the control valve 8 installed at the condenser inlet of the make-up water pipe 7 according to the water level signal 8a of the condenser output by the level switch 11 of the condenser 9. To be done. Normally, the makeup water pump 3 interposed in the makeup water pipe 7 is stopped, and the check valve 20 and the opening / closing valve 21 that operates for a normal time are passed through the makeup water pump bypass pipe 2 that bypasses the makeup water pump 3. Make-up water is supplied to the condenser 9.

Here, when the water level of the condenser 9 is abnormally lowered, or when make-up water is required by the device 10 to which other make-up water is introduced, the start-up signal of the make-up water pump 3 is controlled. It is sent to the control device 13 via the cable 12, is transmitted to the electric motor 5 by the power supply cable 14, and the makeup water pump 3 connected via the fluid coupling 4 is started. In the figure, reference numeral 22 denotes a makeup water pump inlet valve which is opened when the makeup water pump 3 is started, and numeral 23 denotes a check valve.
Therefore, when the makeup water pump 3 is started, the rotation speed of the makeup water pump 3 gradually increases, and the makeup water pump outlet valve 6 arranged in the makeup water pipe 7 at the outlet of the makeup water pump 3 is not used as an electric valve. Even when the pump is started, it is possible to prevent water hammer due to a rapid pressure increase in the makeup water pipe.

Next, a makeup water supply apparatus according to a second embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those in FIG.

In FIG. 2, instead of the fluid coupling 4, a controller 13 for controlling the drive of the electric motor 5 is provided with a rotation speed controller 15.
Is installed additionally. As a result, when the pump 3 is started, the makeup water pump 3 gradually increases in rotation speed under the control of the rotation speed control device 15.

Therefore, even if the makeup water pump outlet valve 6 is not an electrically operated valve, it is possible to prevent water hammer due to a rapid pressure increase in the makeup water pipe 7 when the pump is started. Next, a makeup water supply device according to a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same parts as those in FIG. 2 are designated by the same reference numerals and the description of the structure of those parts will be omitted.

In FIG. 3, pressure detecting devices 16 are installed at a plurality of places in the makeup water pipe 7. This pressure detector
The pressure in the makeup water pipe 7 is detected by 16 and this pressure signal a is input and stored in the pressure storage device 17 in the control device 13. The pressure value and the pressure increase rate stored in the pressure storage device 17 are input to the rotation speed increase speed determination device 18, and the rotation speed increase speed determination device 18 determines whether the pressure increase in the makeup water pipe at the time of starting the pump. It is determined whether or not it is within a predetermined range that does not cause water hammer. Then, when the pressure increase rate and the pressure are out of the predetermined ranges, a signal for reducing the rotation speed of the makeup water pump is output to the rotation speed control device 15.

Therefore, since the pressure increase in the makeup water pipe 7 can be controlled within a predetermined range, the rotation speed of the pump is increased within a range that does not cause water hammer due to a rapid pressure increase in the makeup water pipe at the time of starting the pump. Since the speed can be maximized, the makeup water can be supplied more promptly after the pump start request.

In the present invention, the outlet valve is shown as an example of a manual valve. However, even when the outlet valve is an automatic valve, by applying the present invention, the water hammer can be surely prevented.

[0017]

As described above, according to the first and second aspects.
In the present invention described, it is possible to prevent the water hammer on the piping path accompanying the start-up of the makeup water pump. Further, according to the present invention as set forth in claim 3, in addition to the effects of the above-mentioned invention, the start-up time of the makeup water pump can be shortened, and a makeup water device excellent in operability can be provided.

[Brief description of drawings]

FIG. 1 is a system diagram of a makeup water supply device showing a first embodiment of the present invention.

FIG. 2 is a system diagram of a makeup water supply device showing a second embodiment of the present invention.

FIG. 3 is a system diagram of a makeup water supply device showing a third embodiment of the present invention.

[Explanation of symbols]

1 ... Pure water tank or makeup water tank 2 ... Makeup water pump bypass pipe 3 ... Makeup water pump 4 ... Fluid coupling 5 ... Electric motor 6 ... Makeup water pump outlet valve 7 ... Makeup water pipe 8 ... Control valve 9 ... Condenser 10 … Other devices through which make-up water is introduced 11… Level switch 12… Control cable 13… Control device 14… Power cable 15… Rotation speed control device 16… Pressure detection device 17… Pressure memory device 18… Rotation speed increase speed determination device 20, 23 ... Check valve 21 ... Open / close valve 22 ... Make-up water pump inlet valve

Claims (3)

[Claims] 1. A makeup water supply device for guiding makeup water from a tank for storing makeup water to a condenser through a makeup water pump and a makeup water pump outlet valve to a condenser by means of a makeup water pump and this makeup water. A makeup water supply device characterized in that a fluid coupling is provided between the pump and an electric motor for driving the pump. 2. A rotation speed control device for gradually increasing the rotation speed of the makeup water pump within a predetermined range instead of the fluid coupling. Makeup water supply device. 3. The rotation speed control device inputs the pressure in the makeup water pipe, and increases the rotation speed of the makeup water pump to reduce the rotation speed of the makeup water pump when the rise in the pressure is out of a range that does not cause water hammer. The makeup water supply device according to claim 2, further comprising a speed determination device.