JPS6256401B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention relates to steam power plant equipment, and in particular, to a system for transferring condensate extracted from a condenser through a water storage tank connected to the condenser. This invention relates to improvements in steam power station equipment that supplies steam to steam generators.

(Prior art and problems to be solved by the invention) In general, condensate supply systems in steam power plant equipment such as nuclear power plants have several types of pumps connected in series in order to send a large amount of water to high-pressure reactors, etc. It is located in Therefore, an abnormality in a single pump has a very large effect on the overall operation of the plant, and most of the fluid in the plant is collected in the condenser, so the condenser is prone to corrosion products, etc. Easy to flow in.

Furthermore, since seawater is mainly used as cooling water for the condenser, if seawater leaks, it may flow into the reactor, which poses a serious problem.

Therefore, the condensate extracted from the condenser is purified by a condensate purification device and then collected in a temporary water tank.
It has been proposed to provide a buffering effect in terms of water quantity and water quality control by installing a return line to the condenser in the water storage tank.

That is, FIG. 1 is a schematic system diagram of a conventional device of this kind, in which exhaust steam discharged from a turbine 1 is indirectly cooled and condensed in a condenser 2 to become condensed water, which is collected in a hot well 3. The condensate collected in this hot well 3 is extracted and pressurized by a circulation pump 4, and then sent to condensate purification devices 5 and 6, where the water quality is sufficient to supply water to a nuclear reactor etc. (not shown). After being purified, it is sent to a water storage tank 8 via a heat exchanger 7. Then, the condensate in the water storage tank 8 is again pressurized by the condensate pump 9, heated by a high-pressure heat exchanger (not shown), and supplied to a nuclear reactor or the like.

On the other hand, the water tank 8 is connected to the condenser 2 via a return line 11 having a control valve 10, and the water level in the water tank 8 is detected by a signal from a water level detector 12 that detects the water level in the water tank 8. By controlling the opening and closing of the control valve 10, the return line 11 is removed from the water tank 8.
The amount of water returned to the condenser 2 via the .

By the way, in the case of a nuclear power plant, in a configuration in which the system including the condensate purification devices 5 and 6 and the water supply system to the reactor are made independent, and the water storage tank 8 is provided in the middle, If there is an abnormality in the equipment or equipment in the system, including water purification equipment,
Because there is condensate stored in the water storage tank 8, there is no instantaneous effect on the water supply to the reactor side, and by performing prompt control operations during that time, the plant can be safely shut down or the output reduced. Can be done. In other words, if it is detected that an abnormality has occurred in the system including the condensate purification system, if a signal is immediately sent to the reactor to reduce the output or stop the reactor, water will be stored in the water tank 8, so the front water supply will be lost. The risk of this happening is greatly reduced. Furthermore, since the system including the condensate purification device can be operated independently, water purification and piping and equipment in the system can be sufficiently cleaned before starting the plant. Furthermore, it has various advantages such as being able to keep the amount of condensate passing through the condensate purification device constant regardless of fluctuations in the output of the plant, and maintaining a high purification capacity.

However, in such a condensate system, the water level of the water tank 8 changes due to the mismatch between the flow rates upstream and downstream of the water tank 8, and the saturation temperature extracted by the large-capacity circulation pump changes. Since the condensate is heated by the heat exchanger and partially vaporized in the water tank 8, the condenser 2 and the water tank 8 need to be balanced with each other. Therefore, in the conventional device as well, the water storage tank 8 and the condenser 2 are communicated with each other through the balance pipe 13, as shown in FIG. The steam vaporized in the water storage tank 8 flows to the condenser 2 via the balance pipe 13, but since the inside of the condenser is a vacuum region, the specific volume of the steam is large, and the balance pipe 13 Considering corrosion, vibration, etc., the diameter of the balance tube 13 will be large, exceeding 1000 mmφ. Moreover, this causes the heat given by the heat exchanger 7 to escape, reducing the efficiency of the plant. Furthermore, the amount of water sent to the condensate pump 9 is reduced by the amount of steam released to the condenser 2, and in order to compensate for this decrease, the circulation pump 4, condensate purifiers 5 and 6, and heat exchanger 7 are used.
etc., it is necessary to increase the capacity, and there are disadvantages such as an increase in equipment costs and a loss of operating power for the circulation pump 4.

In view of these points, it is an object of the present invention to provide highly reliable steam power plant equipment that is free from the above-mentioned disadvantages.

[Structure of the invention]

The present invention provides a steam power station facility in which condensate extracted from a condenser is supplied to a steam generator via a water storage tank connected to the condenser, and a throttle device that connects the water storage tank and the condenser. This feature is characterized in that they are communicated with each other via a balanced conduit provided with.

(Example) An example of the present invention will be described below with reference to FIG.

In FIG. 2, the condensate extracted and pressurized from the condenser 2 by the circulation pump 4 is transferred to the condensate purification device 5,
6 and a heat exchanger 7 before being sent to a water storage tank 8.

A portion of the condensate in the water storage tank 8 is returned to the condenser 3 via a return line 11, and the remaining condensate is supplied to a nuclear reactor or the like via a condensate pump 9. In addition, water tank 8
The steam evaporated inside is returned to the condenser 2 via the balance pipe 13.

The above is the same as the conventional device shown in FIG. 1, but in the present invention, a throttle device 14 is provided in the middle of the balance tube 13.

By the way, the throttle device 14 is like an orifice that provides enough throttle to maintain the pressure in the water storage tank 8 at about the saturation pressure of the condensate temperature after the heat exchanger 7, and is used for condensate pumps etc. If an abnormality occurs in water system equipment and water is supplied to the reactor etc. only by condensed water in the water storage tank 8, the balance pipe 13
It is necessary that the throttle device 14 does not reduce the pressure in the water tank 8 and thereby increase the load on the condensate pump 9. In addition, when considering the reduction in the diameter of the balance tube 13, in order to prevent vibration and erosion of the balance tube 13, it is necessary to suppress the steam flow rate in the balance tube 13 to about 1/2 at the most. It is desirable that the expansion device is capable of applying at least a pressure that satisfies this condition.

Thus, the steam generated in the water storage tank 8 is returned to the condenser 2 through the balance pipe 13, but in this case, since the balance pipe 13 is equipped with a throttle device 14, the water storage tank 8 A pressure difference is generated between the inside and the condenser 2, the pressure inside the water storage tank 8 increases, and the amount of steam generated from the condensate is suppressed. Therefore, the diameter of the balance tube 13 can be reduced accordingly, and problems such as vibration and tube erosion caused by a large amount of steam flowing through the large-diameter balance tube can be solved. can do. In addition, in the conventional device, all of the large amount of steam generated in the water storage tank 8 is released to the condenser 2, which reduces the flow rate to the condensate pump 9, and at the same time reduces the amount of heat given by the heat exchanger 7. All of it will be released to the condenser 2, resulting in a loss of heat, but in the present invention, the balance pipe 13 is provided with a throttle device 14, so the pressure inside the water tank 8 increases and the condenser is lost. The amount of water vapor produced is reduced, thereby preventing a reduction in the flow rate to the condensate pump 9 and a loss of heat.

〔Effect of the invention〕

As explained above, in the present invention, in a condensate system that has a water storage tank and a return line to the condenser after the condensate extracted from the condenser is purified by the condensate purification device, the water storage tank and A throttling device is installed in the balance pipe that connects the condenser to increase the pressure inside the water storage tank to about the saturation pressure of the condensate, so it is possible to suppress the amount of evaporation of the condensate in the water storage tank. This has the effect of reducing the diameter of the balance pipe, preventing a decrease in the flow rate of condensate to the condensate pump, and preventing loss of heat in the condensate.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of conventional steam power plant equipment.
FIG. 2 is a schematic system diagram of the steam power station equipment in the present invention. 1...Turbine, 2...Condenser, 4...Circulation pump,
5, 6...Condensate purification device, 8...Water tank, 9...Condensate pump, 10...Control valve, 13...Balance pipe, 14...
Squeezing device.

Claims (1)

[Claims] 1. In steam power plant equipment in which condensate extracted from a condenser is supplied to a steam generator via a water storage tank connected to the condenser, a throttling device is installed to connect the water storage tank and the condenser. 1. Steam power station equipment, characterized in that the equipment is connected to each other via balanced pipelines.