JP2006112402A - Nuclear power plant and method of operation control for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nuclear power plant easily adjustable to meet the requirement for maintaining the output of a nuclear reactor constant even if the pressure of steam from a nuclear reactor pressure vessel varies up and down from a rated pressure by reducing an energy loss by utilizing a steam increasing/decreasing valve with less pressure loss and a method of operation control for the nuclear power plant. <P>SOLUTION: In this nuclear power plant, a pressure header 27, a main steam stop valve 29, and the steam increasing/decreasing valve 30 are interposed in a main steam pipe 25 connecting the nuclear reactor pressure vessel 20 to a steam turbine, and the flow of the steam from the nuclear reactor pressure vessel is fed to the steam turbine after being controlled by the steam increasing/decreasing valve. A power is generated in the steam turbine, turbine exhaust gases are condensed in a condenser 24 and returned to the nuclear reactor pressure vessel. Then, the pressure header is connected to the condenser through a turbine bypass pipe 32 for escaping the steam from the nuclear reactor pressure vessel to the condenser. The nuclear power plant also comprises a steam pressure regulating device 34 having an input side connected to the main steam pipe between the downstream side of the pressure header and the upstream side of the steam increasing/decreasing valve and regulating the pressure of the steam from the nuclear reactor pressure vessel. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a nuclear power plant suitable for adjusting the pressure of steam supplied from a reactor pressure vessel to a steam turbine to maintain a constant reactor output and an operation control method thereof.

  In a boiling water nuclear power plant, when the pressure in the core of the reactor pressure vessel decreases, the proportion of voids in the reactor water increases and neutrons are absorbed, so that fission is suppressed. In order to adjust the reactor power so that there is no decrease in the reactor power, the steam pressure is adjusted when the steam from the reactor pressure vessel is supplied to the steam turbine. .

  The nuclear power plant includes a reactor pressure vessel 1, a high-pressure turbine 2, a combined intermediate valve 3, a low-pressure turbine 4, and a condenser 5. The steam generated from the reactor pressure vessel 1 is expanded by the high-pressure turbine 2 and powered. The high-pressure turbine exhaust that has completed the expansion work is supplied to the low-pressure turbine 4 through the combined intermediate valve 3, and the expansion work is also generated here to generate power, and the low-pressure turbine that has completed the expansion work by the low-pressure turbine 4. The exhaust gas is condensed by the condenser 5 and returned again to the reactor pressure vessel 1 as condensate / feed water.

  In the nuclear power plant, the reactor pressure vessel 1 and the high-pressure turbine 2 are connected by, for example, four main steam pipes 6 and main steam reed pipes 7.

  The main steam pipe 6 and the main steam reed pipe 7 are provided with a pressure gauge 9, a main steam stop valve 10, and a steam control valve 11 corresponding to the number of pipes, in addition to the pressure header 8 that shares the number of pipes. After the steam supplied from the container 1 is once collected in the pressure header 8, the flow rate is adjusted by the steam control valve 11 and supplied to the high-pressure turbine 2.

  Further, the pressure header 8 includes a turbine bypass pipe 14 that is connected to the condenser 5 with a turbine bypass valve 12 interposed in the middle thereof. When an emergency event such as a load interruption occurs, the main steam stop valve 10 or the steam control valve is provided. The valve 11 is closed, and the steam generated from the reactor pressure vessel 1 is directly flowed to the condenser 13 to perform standby operation without stopping the reactor pressure vessel 1 until the accident is restored. .

  In the nuclear power plant having such a configuration, the steam control valve 11 performs constant steam pressure control when supplying steam generated from the reactor pressure vessel 1 to the high-pressure turbine 2.

  That is, the steam control valve 11 is provided with an arithmetic circuit (not shown) for calculating a set steam pressure signal, a turbine speed signal, a turbine load signal and the like in addition to the actual steam pressure signal detected from the pressure gauge 9. Each of these signals is calculated by an arithmetic circuit to create a valve opening / closing signal, the valve body is opened / closed based on the generated calculation signal, the steam pressure is adjusted to be constant, and the reactor output is based on the adjusted constant steam pressure. Was kept constant.

In addition, many inventions, such as Unexamined-Japanese-Patent No. 5-312995 (patent document 1) and Unexamined-Japanese-Patent No. 61-218996 (patent document 2), are disclosed by invention which adjusts vapor | steam pressure constant.
JP-A-5-312995 Japanese Patent Laid-Open No. 61-218996

  In Patent Document 1 and Patent Document 2 described above, calculation is performed based on the detected steam pressure signal and the like, a valve opening / closing signal is generated, the generated valve opening / closing signal is given to the steam control valve 11, and steam from the reactor pressure vessel 1 is generated. Although the pressure is adjusted to be constant and the constant power of the reactor is maintained based on the adjusted steam pressure, the calculation circuit is relatively simple and easy to operate. .

  However, it still has some problems, one of which is the pressure loss that occurs when the valve opens and closes.

  Conventionally, when the system frequency fluctuates during operation and the steam pressure fluctuates accordingly, the steam control valve 11 immediately opens and closes the valve body, for example, four valve bodies. In that case, the pressure loss which generate | occur | produces becomes large on the relationship which performs the throttle | throttle operation (full arc admission) which opens and closes four valve bodies simultaneously.

When the pressure loss increases, the energy consumption required to generate the electrical output (power generation end output) also increases. For example, by reducing the loss of the steam control valve by 1 kg / cm ² in a 1 million kW class power plant, Excess energy is consumed to meet the electricity bill of tens of millions of yen per year.

  For this reason, in the turbine industry field, as a part of improving turbine performance under strengthening competitiveness, for example, as seen in JP-A-2002-97903, structural improvements that simplify the steam passage are performed, A technique for further reducing the pressure loss and further increasing the electric output has been proposed, and the pressure loss of the recent steam control valve has been reduced.

  On the other hand, the steam control valve 11 is so designed that there is not enough room to adjust even if there is a large pressure fluctuation in terms of control characteristics so as to reduce the pressure loss. For this reason, when the steam pressure fluctuates beyond the design allowable range on the inlet side of the steam control valve 11, the steam pressure cannot be adjusted to a constant value, and the reactor power is reduced under the constant steam pressure. There remained some anxiety that caused a great deal of damage to the design philosophy that kept it constant.

  The present invention has been made based on such circumstances, and effectively uses a steam control valve with reduced pressure loss, reduces energy loss and increases electrical output, while reducing the pressure from the reactor pressure vessel. A nuclear power plant that can be easily adjusted to a predetermined pressure (rated pressure) even if the steam pressure fluctuates higher or lower than a predetermined pressure (rated pressure), and that sufficiently maintains a constant reactor output, and its An object is to provide an operation control method.

  In order to achieve the above-mentioned object, the nuclear power plant according to the present invention includes a pressure header, a main steam stop valve, and a steam control valve in a main steam pipe connecting a reactor pressure vessel and a steam turbine, The steam flow from the reactor pressure vessel is controlled by the steam control valve and supplied to the steam turbine, power is generated by the steam turbine, and the turbine exhaust is condensed by the condenser and returned to the reactor pressure vessel. , In a nuclear power plant configured to connect the pressure header and the condenser with a turbine bypass pipe that allows steam from the reactor pressure vessel to escape to the condenser, the downstream side of the pressure header and the steam control valve An input side is connected to the main steam pipe between the upstream side, and a steam pressure adjusting device for adjusting the pressure of the steam from the reactor pressure vessel is provided.

  The nuclear power plant according to the present invention is configured to connect the output side of the steam pressure adjusting device to the inlet side of the low-pressure turbine of the steam turbine in order to achieve the above-described object.

  In addition, in the nuclear power plant according to the present invention, the steam pressure adjusting device includes a relief valve and a steam relief pipe in order to achieve the above-described object.

  In addition, in the nuclear power plant according to the present invention, the steam relief pipe includes a decompression device in order to achieve the above-described object.

  In order to achieve the above-mentioned object, the nuclear power plant according to the present invention includes a main steam stop valve and a steam control valve interposed in a main steam pipe connecting a reactor pressure vessel and a steam turbine. A configuration in which the steam flow from the reactor pressure vessel is controlled by the steam control valve and supplied to the steam turbine, power is generated by the steam turbine, and the turbine exhaust is condensed by a condenser and returned to the reactor pressure vessel. In the nuclear power plant, a steam pressure adjusting device for adjusting a pressure of steam from the reactor pressure vessel is provided between the main steam pipe and a condenser between the upstream side of the steam control valve, and the steam The pressure adjusting device includes a pressure reducing device.

  In addition, in the nuclear power plant according to the present invention, the steam pressure adjusting device includes a relief valve and a steam relief pipe in order to achieve the above-described object.

  Further, in the nuclear power plant according to the present invention, in order to achieve the above-described object, the steam pressure adjusting device is provided by the number of main steam pipes.

  In order to achieve the above-described object, the nuclear power plant according to the present invention includes a main header connecting a reactor pressure vessel and a steam turbine with a pressure header, a main steam stop valve, and a steam control valve. The flow rate of steam from the reactor pressure vessel is controlled by the steam control valve and supplied to the steam turbine, power is generated by the steam turbine, and the turbine exhaust is condensed by a condenser, and the reactor pressure vessel In the nuclear power plant in which the pressure header and the condenser are connected by a turbine bypass pipe for returning the steam from the reactor pressure vessel to the condenser, the main steam for the number of the main steam pipes A stop valve is provided, and fewer steam control valves than the number of the main steam pipes are provided.

  In order to achieve the above object, a nuclear power plant according to the present invention includes a steam control valve in a main steam pipe connecting a reactor pressure vessel and a steam turbine, and the steam turbine is connected to the steam turbine from the reactor pressure vessel. When supplying steam to the steam pressure when the pressure of the steam supplied from the reactor pressure vessel to the steam turbine is fluctuating with respect to a predetermined pressure, the steam control valve is given a valve opening degree, Among the steam turbines, a valve opening degree is given to a combination intermediate valve provided in the middle between the high-pressure turbine and the low-pressure turbine to adjust the pressure of the steam.

  In order to achieve the above object, a nuclear power plant according to the present invention includes a steam control valve in a main steam pipe connecting a reactor pressure vessel and a steam turbine, and the steam turbine is connected to the steam turbine from the reactor pressure vessel. When supplying steam to the main steam pipe upstream of the steam control valve, when the pressure of steam supplied from the reactor pressure vessel to the steam turbine fluctuates with respect to a predetermined pressure, A valve opening command is given to the relief valve of the provided steam pressure adjusting device.

  In order to achieve the above-mentioned object, the nuclear power plant according to the present invention includes a main steam stop valve corresponding to the number of main steam pipes connecting the reactor pressure vessel and the steam turbine. At least one of the number is provided with a steam control valve, and when supplying steam from the reactor pressure vessel to the steam turbine, the first main steam stop valve is opened among the main steam stop valves. Then, the steam control valve is opened, the second main steam stop valve is opened, the steam control valve is closed, and the remaining main steam stop valve is opened. The steam control valve is repeatedly opened and closed, and finally the steam control valve is opened.

  In order to achieve the above-mentioned object, the nuclear power plant according to the present invention includes a main steam stop valve corresponding to the number of main steam pipes connecting the reactor pressure vessel and the steam turbine. When supplying steam from the reactor pressure vessel to the steam turbine, the steam pressure supplied from the reactor pressure vessel to the steam turbine fluctuates with respect to a predetermined pressure. When the valve is open, give the valve opening degree to the steam control valve or close the steam control valve with one of the main steam stop valves having the steam control valve on the downstream side opened. At the same time, it is selected whether to sequentially close the remainder of the main steam stop valve.

  The nuclear power plant and the operation control method thereof according to the present invention control the fluctuating steam pressure when supplying steam from the reactor pressure vessel to the steam turbine through the main steam stop valve and the steam control valve. The steam pressure (rated pressure) can be easily controlled and the reactor power can be maintained constant.

  Hereinafter, embodiments of a nuclear power plant and an operation control method thereof according to the present invention will be described with reference to the drawings and the reference numerals attached to the drawings.

  FIG. 1 is a schematic system diagram showing a first embodiment of a nuclear power plant according to the present invention.

  The nuclear power plant according to this embodiment includes a reactor pressure vessel 20, a high-pressure turbine 21, a combined intermediate valve 22, a low-pressure turbine 23, and a condenser 24 as main components, and steam from the reactor pressure vessel 20 is high-pressure. The turbine 21 performs expansion work to generate power, and the expanded high-pressure turbine exhaust is combined and supplied to the low-pressure turbine 23 via the intermediate valve 22. Again, expansion work is performed to generate power, and the low-pressure after expansion The turbine exhaust is condensed in the condenser 24, and is returned to the reactor pressure vessel 20 through the condensate water supply pipe 33 as condensate and feed water.

  In the nuclear power plant according to the present embodiment, the reactor pressure vessel 20 and the high-pressure turbine 21 are connected by, for example, four main steam pipes 25 and main steam reed pipes 26.

  From the reactor pressure vessel 20 side, the main steam pipe 25 and the main steam lead pipe 26 are provided with a pressure header 27 shared by the number of pipes, a pressure gauge 28, a main steam stop valve 29, and a steam control valve 30 corresponding to the number of pipes. The steam supplied from the reactor pressure vessel 20 is once collected in the pressure header 27, the flow rate is adjusted by the steam control valve 30, and the steam is supplied to the high pressure turbine 21.

  The pressure header 27 includes a turbine bypass pipe 32 that is connected to the condenser 24 with a turbine bypass valve 31 interposed in the middle thereof, and closes the main steam stop valve 29 when an emergency event such as load interruption occurs. The steam generated from the reactor pressure vessel 20 is released to the condenser 24 via the turbine bypass pipe 32.

  Further, a steam pressure adjusting device 34 for adjusting the pressure of the steam generated from the reactor pressure vessel 20 is provided between the outlet side of the pressure header 27 and the condenser 24.

  This steam pressure adjusting device 34 adjusts to a predetermined pressure when the pressure of the steam generated from the reactor pressure vessel 20 fluctuates higher or lower than a predetermined pressure (rated pressure). The steam relief pipe 37 is connected to the condenser 24 through a relief valve 35 and an orifice 36.

  The reason why the steam relief pipe 37 is provided with the orifice 36 is that the high steam pressure is reduced at the orifice 36 and the impact force when the steam relief pipe 37 is supplied to the condenser 24 is alleviated.

  When the pressure of the steam generated from the reactor pressure vessel 20 fluctuates higher or lower than a predetermined pressure, the steam pressure is adjusted by the steam control valve 30 and the steam pressure adjusting device 34.

  First, when the pressure gauge 28 detects that the pressure of the steam generated from the reactor pressure vessel 20 is lower than a predetermined pressure on the inlet side of the steam control valve 30, the steam control valve 30 For example, four valve bodies are simultaneously set to the valve throttle opening, and the pressure of the steam from the reactor pressure vessel 20 is increased.

  On the other hand, for example, when an accident occurs in the transmission line system and a load interruption occurs, the high and low pressure turbines 21 and 23 and the generator (not shown) exceed the rated speed and become overspeed. In this case, the steam control valve 30 is controlled to reduce the amount of steam by reducing the opening of the valve body in order to suppress overspeed. At this time, although the pressure of the steam from the reactor pressure vessel 20 tends to increase, the steam pressure adjusting device 34 opens the relief valve 35 and causes the steam flowing from the relief valve 35 to flow through the orifice 36 and the steam relief pipe 37. Then, the amount of steam supplied to the condenser 24 and supplied to the high and low pressure turbines 21 and 23 is decreased, and the rotational speeds of the high and low pressure turbines 21 and 23 and the generator are set to the rated rotational speed.

  Thus, in the present embodiment, the steam pressure adjusting device 34 is provided on the outlet side of the pressure header 27 in the main steam pipe 25 connecting the reactor pressure vessel 20 and the high-pressure turbine 21, and the steam from the reactor pressure vessel 20 is provided. When the pressure of the steam is lower than a predetermined pressure (rated pressure), the valve throttle opening is given to the valve body of the steam control valve 30 to increase the steam pressure and control to a predetermined pressure (rated pressure). On the other hand, when an accident such as a system occurs and the steam from the reactor pressure vessel 20 exceeds a predetermined pressure (rated pressure) while the valve opening of the steam control valve 30 is reduced, the steam pressure is adjusted. Since the apparatus 34 is configured to supply the steam from the reactor pressure vessel 20 to the condenser 24, the rotational speeds of the high and low pressure turbines 21, 23, etc. can be easily set to the rated rotational speed.

  2 and 3 are diagrams for explaining the nuclear power plant operation control method according to the first embodiment.

In FIG. 2, steam generated from the reactor pressure vessel 20 flows in the order of the pressure header 27, the main steam stop valve 29, the steam control valve 30, the high pressure turbine 21, the combined intermediate valve 22, the low pressure turbine 23, and the condenser 24. For example, if there is a load fluctuation due to a system fault during operation, the high-pressure turbine 21, the low-pressure turbine 23, and the generator (not shown) that are shaft-coupled at the time of transition exceed the rated speed and overspeed. The valve throttle opening is given to the valve body of the steam control valve 30 to reduce the pressure of the steam as shown by the one-dot chain line BP ₁ and the valve body of the combined intermediate valve 22 is also a valve. given aperture size, as indicated by a chain line BP _2, it is obtained by pressure drop vapor.

In this way, not only the overspeed of the high and low pressure turbines 21, 23 is given to the valve body of the steam control valve 30, but also the valve body of the combined intermediate valve 22 is given a valve opening degree, the pressure drop BP ₁ steam steam control valve 30, since increased the system loss of the steam supply system by adding a combined pressure drop BP ₂ steam of the intermediate valve 22, combined with the pressure drop BP ₁ of the steam control valve 30 high in each small share of the pressure drop BP ₂ intermediate valve 22, it is possible to settle easily rated rotational speed of the overspeed such as low-pressure turbine 21, 23.

  3 increases the frequency when the relief valve 35 of the steam pressure adjusting device 34 shown in FIG. 1 is opened, and is repeatedly performed, so that the steam from the reactor pressure vessel 20 flows out to the condenser 24. It has been made.

  Conventionally, when there is a load fluctuation due to a system fault in the high and low pressure turbines 21, 23, etc., the steam control valve 30 gives a large valve throttle opening to the valve body with respect to the full opening as shown by the solid line in FIG. 5. The pressure of the steam from the reactor pressure vessel 20 was returned to a predetermined pressure (rated pressure).

  However, in FIG. 3, the relief valve of the steam pressure regulator is opened when the reactor pressure exceeds the rated pressure, closed when the reactor pressure falls below the rated pressure, and repeatedly opened and closed. The throttle opening degree given to the valve body of the adjusting valve is also small with respect to the full opening.

  In this way, the number of times the relief valve is opened and closed is increased and repeated, so that the pressure loss can be reduced by reducing the valve opening degree of the valve body of the steam control valve. The pressure of the steam from the reactor pressure vessel can be easily set to a predetermined pressure (rated pressure) with a small pressure loss.

  And this embodiment plays the role of a turbine bypass pipe, since the steam which flows through the steam pressure adjusting device 34 is supplied to the condenser via the orifice.

  In the present embodiment, for example, the steam pressure adjusting device 34 is provided in one main steam pipe 25 among the four main steam pipes 25. However, the present embodiment is not limited to this example. For example, as shown in FIG. Further, steam pressure adjusting devices 34a, 34b,... May be provided corresponding to the number of main steam pipes 25 (second embodiment).

  For example, as shown in FIG. 5, the steam relief pipe 37 of the steam pressure adjusting device 34 may be connected to the inlet side of the combined intermediate valve 22 (third embodiment). When the steam relief pipe 37 is provided on the inlet side of the intermediate valve 22, it is effective in that the recovered steam is expanded by the low-pressure turbine 23 and the recovered energy is reused.

  FIG. 6 is a schematic system diagram showing a fourth embodiment of the nuclear power plant according to the present invention.

  In the present embodiment, the steam control valve 30 is provided in at least one of the plural main steam pipes 25 and the main steam reed pipes 26 that connect the high pressure turbine 21 to the reactor pressure vessel 20. It is provided. In addition, the pressure header 27, the pressure gauge 28, and the main steam stop valve 29 have taken the same embodiment as 1st Embodiment.

  As described above, in the present embodiment, the steam control valve 30 is connected to at least one of the plurality of main steam pipes 25 and the main steam reed pipes 26 that connect the high-pressure turbine 21 to the reactor pressure vessel 20. The pressure loss of the steam from the reactor pressure vessel 20 flowing through the main steam pipe 25 and the main steam reed pipe 26 is reduced, so that the expansion work in the high-pressure turbine 21 and the low-pressure turbine 23 is increased, and the electric output is increased. Can be increased.

  FIG. 7 is a diagram for explaining the nuclear power plant operation control method of the fourth embodiment.

  A plurality of pipes shown in FIG. 6, for example, four main steam pipes 25 and main steam reed pipes 26 are provided with main steam stop valves 29 corresponding to the number of pipes, and steam is provided to at least one of the pipes. The open / close behavior mode of the main steam stop valve 29 and the steam control valve 30 is improved when the load increases due to the provision of the control valve 30.

  That is, as shown in FIG. 9, the conventional nuclear power plant has a main steam stop valve 10 and steam corresponding to a plurality of pipes, for example, four main steam pipes 6 and main steam reed pipes 7. An adjusting valve 11 was provided.

  Further, as shown in FIG. 10, the valve opening relationship between the main steam stop valve 10 and the steam control valve 11 provided corresponding to the number of main steam pipes 6 and main steam lead pipes 7 is four main steams. After all the stop valves 10 are fully opened, all the four steam control valves 11 are simultaneously opened to gradually increase the degree of opening until the turbine load reaches 100%. It was.

  However, in this embodiment, for example, the main steam stop valve 29 is provided corresponding to the number of pipes for the four main steam pipes 25 and the main steam lead pipes 26, and at least one of the plurality of pipes is provided. Since the steam control valves 30 are provided in the above number of pipes, the valve opening relationship between the main steam stop valve 29 and the steam control valve 30 is improved as shown in FIG. .

  FIG. 7 is a diagram showing the valve opening relationship between the main steam stop valve 29 and the steam control valve 30. At the beginning of the operation, all the main steam stop valves 29 are fully closed, and the steam control valve 30 is, for example, 1 The first main steam stop valve is fully opened from the fully closed state.

  When the first main steam stop valve is fully opened, the steam control valve is opened. After the steam control valve is fully opened, the steam control valve is closed in accordance with the opening of the second main steam stop valve, and at the same time the second main steam stop valve is fully opened, the steam control valve is closed. The steam control valve is opened again. After the steam control valve is fully open, the steam control valve is closed in accordance with the opening of the third main steam stop valve. Close the valve.

  Such valve opening behavior is sequentially repeated, and after the fourth main steam stop valve is fully opened, the steam control valve is fully opened to reach the rated load.

  By the way, under the valve opening relationship between the main steam stop valve and the steam control valve described above, when the pressure fluctuation of the steam supplied from the reactor pressure vessel is relatively small during load increase operation or rated load operation, As shown by A part of FIG. 8, it respond | corresponds only by a steam control valve, gives a valve throttle opening to a valve body, and raises a steam pressure.

  Further, when an accident occurs in the system during operation, a relatively low load fluctuation occurs in the high and low pressure turbines, and the main steam pressure fluctuates more than part A, this embodiment is shown in FIG. As shown in the section, the steam control valve and the second main steam stop valve are closed while the first main steam stop valve is opened, and the steam pressure is restored to a predetermined pressure (rated pressure).

  Furthermore, when there is a large fluctuation (decrease) in the main steam pressure, the steam control valve and the second main steam stop valve are kept open while the first main steam stop valve is opened, as shown in part C of FIG. In addition to closing the valve, all the remaining main steam stop valves are closed to restore the vapor pressure to a predetermined pressure (rated pressure).

  As described above, the main steam pipe and the main steam reed pipe for connecting the reactor pressure vessel and the high-pressure turbine are provided with four main steam stop valves corresponding to, for example, four main steam pipes among a plurality of pipes. Fluctuation in the pressure of steam supplied from the reactor pressure vessel to the high-pressure turbine is large or small on the condition that at least one of the four main steam pipes is provided with a steam control valve. Depending on the condition, the throttle opening is given only to the steam control valve, or in addition to the adjustable steam control valve, the second to fourth type steam stop valves are closed, so the steam supplied from the reactor pressure vessel Regardless of the pressure fluctuation, the pressure can be easily adjusted to a predetermined pressure (rated pressure), and the reactor power can be maintained constant.

1 is a schematic system diagram showing a first embodiment of a nuclear power plant according to the present invention. The figure which shows the pressure drop of the steam in the nuclear power plant operation control method of 1st Embodiment. The figure which shows opening and closing of the relief valve at the time of the steam pressure fluctuation | variation in the nuclear power plant operation control method of 1st Embodiment. The schematic system diagram which shows 2nd Embodiment of the nuclear power plant which concerns on this invention. The schematic system diagram which shows 3rd Embodiment of the nuclear power plant which concerns on this invention. The schematic system diagram which shows 4th Embodiment of the nuclear power plant which concerns on this invention. The figure for demonstrating the nuclear power plant operation control method of 4th Embodiment. The figure for demonstrating the valve opening behavior of the steam control valve of FIG. 7, and the main steam stop valve. Schematic system diagram showing a conventional nuclear power plant. The figure for demonstrating the valve opening condition of the conventional main steam stop valve and a steam control valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor pressure vessel 2 High pressure turbine 3 Combination intermediate valve 4 Low pressure turbine 5 Condenser 6 Main steam pipe 7 Main steam lead pipe 8 Pressure header 9 Pressure gauge 10 Main steam stop valve 11 Steam control valve 12 Turbine bypass valve 14 Turbine bypass Pipe 20 Reactor pressure vessel 21 High pressure turbine 22 Combined intermediate valve 23 Low pressure turbine 24 Condenser 25 Main steam pipe 26 Main steam lead pipe 27 Pressure header 28 Pressure gauge 29 Main steam stop valve 30 Steam control valve 31 Turbine bypass valve 32 Turbine Bypass pipe 33 Condensate / feed water pipe 34, 34a, 34b Steam pressure adjusting device 35, 35a, 35b Relief valve 36, 36a, 36b Orifice 37, 37a, 37b Steam relief pipe

Claims (12)

A main steam pipe connecting the reactor pressure vessel and the steam turbine is provided with a pressure header, a main steam stop valve and a steam control valve, and the steam flow rate from the reactor pressure vessel is controlled by the steam control valve. A turbine bypass pipe that supplies power to the steam turbine, generates power in the steam turbine, condenses the turbine exhaust in the condenser and returns it to the reactor pressure vessel, and releases the steam from the reactor pressure vessel to the condenser In the nuclear power plant configured to connect the pressure header and the condenser,
An input side is connected to the main steam pipe between the downstream side of the pressure header and the upstream side of the steam control valve, and a steam pressure adjusting device for adjusting the pressure of steam from the reactor pressure vessel is provided. A nuclear power plant. 2. The nuclear power plant according to claim 1, wherein an output side of the steam pressure adjusting device is connected to an inlet side of a low pressure turbine of the steam turbine. The nuclear power plant according to claim 1 or 2, wherein the steam pressure adjusting device comprises a relief valve and a steam relief pipe. The nuclear power plant according to claim 3, wherein the steam relief pipe includes a decompression device. A main steam pipe connecting the reactor pressure vessel and the steam turbine is provided with a main steam stop valve and a steam control valve, and the steam flow rate from the reactor pressure vessel is controlled by the steam control valve. In a nuclear power plant configured to supply, generate power with the steam turbine, condense the turbine exhaust with a condenser and return it to the reactor pressure vessel,
A steam pressure adjusting device for adjusting the pressure of steam from the reactor pressure vessel is provided between the main steam pipe and the condenser between the upstream side of the steam control valve, and the steam pressure adjusting device is depressurized. A nuclear power plant characterized by comprising an apparatus. 6. The nuclear power plant according to claim 5, wherein the steam pressure adjusting device comprises a relief valve and a steam relief pipe. The nuclear power plant according to claim 1 or 5, wherein the steam pressure adjusting device is provided by the number of main steam pipes. A main steam pipe connecting the reactor pressure vessel and the steam turbine is provided with a pressure header, a main steam stop valve and a steam control valve, and the steam flow rate from the reactor pressure vessel is controlled by the steam control valve. A turbine bypass pipe that supplies power to the steam turbine, generates power in the steam turbine, condenses the turbine exhaust in the condenser and returns it to the reactor pressure vessel, and releases the steam from the reactor pressure vessel to the condenser In the nuclear power plant configured to connect the pressure header and the condenser,
A nuclear power plant comprising a number of main steam pipes corresponding to the number of main steam pipes and a number of steam control valves less than the number of main steam pipes. A main steam pipe connecting the reactor pressure vessel and the steam turbine is provided with a steam control valve, and when supplying steam from the reactor pressure vessel to the steam turbine, the reactor pressure vessel is set against a predetermined pressure. When the pressure of the steam supplied to the steam turbine fluctuates, a valve throttle opening is given to the steam control valve, and a combined intermediate valve provided between the high-pressure turbine and the low-pressure turbine in the steam turbine A method for controlling operation of a nuclear power plant, characterized in that a valve throttle opening is provided to adjust the pressure of the steam. A main steam pipe connecting the reactor pressure vessel and the steam turbine is provided with a steam control valve, and when supplying steam from the reactor pressure vessel to the steam turbine, the reactor pressure vessel is set against a predetermined pressure. When the pressure of the steam supplied to the steam turbine fluctuates from, a valve opening command is given to a relief valve of a steam pressure adjusting device provided in the main steam pipe upstream of the steam control valve. Nuclear power plant operation control method. A main steam stop valve is provided corresponding to the number of main steam pipes connecting the reactor pressure vessel and the steam turbine, and at least one of the pipes is provided with a steam control valve, and the reactor pressure vessel When supplying steam to the steam turbine from the main steam stop valve, after opening the first main steam stop valve, the steam control valve is opened, and the second main steam stop valve is further opened. After the valve is opened, the steam control valve is closed, and the steam control valve is repeatedly opened and closed while the remaining main steam stop valves are opened, and finally the steam control valve is opened. A nuclear power plant operation control method characterized by causing a valve to operate. A main steam stop valve is provided corresponding to the number of main steam pipes connecting the reactor pressure vessel and the steam turbine, and a steam control valve less than the number of pipes is provided, and steam is supplied from the reactor pressure vessel to the steam turbine. When the pressure of the steam supplied from the reactor pressure vessel to the steam turbine fluctuates with respect to a predetermined pressure, a valve throttle opening is given to the steam control valve, or downstream Selecting whether to close the steam control valve and sequentially close the rest of the main steam stop valve while one of the main steam stop valves having the steam control valve on the side is opened. A nuclear power plant operation control method characterized by the above.

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