Forced air cooling system and method for nuclear turbine

Abstract

The invention relates to the field of nuclear turbine operation, in particular to a nuclear turbine forced air cooling system and method. The system comprises a steam turbine steam loop, an air generation and control module and a shaft seal air extraction module, and the air generation and control module is connected to a high-pressure drain tank, a medium-pressure water conveying pipe and a medium-pressure extraction steam through compressed air inlet hoses; and the shaft seal air exhaust module is connected with the middle air seal. The method comprises the steps that after the steam turbine breaks vacuum, it is confirmed that the state of the steam turbine meets the input condition of the nuclear steam turbine forced air cooling system; an exhaust fan is started, an air generation and control module is put into operation, the air flow is controlled to reach a preset value, and the temperature and pressure values of air are controlled to be preset values; air is controlled to enter the steam turbine according to the preset flow, the air running flow path comprises a high-pressure flow path, a first medium-pressure flow path and a second medium-pressure flow path, and the shaft seal air exhaust module exhausts air in the steam turbine; through air circulation, rapid cooling of the steam turbine is achieved. According to the invention, safe, reliable and efficient rapid cooling is realized, the shutdown maintenance time of the nuclear turbine is saved, and the availability of a unit is improved.

Description

Technical Field

[0001] The invention relates to the field of nuclear power steam turbine operation, and in particular to a nuclear power steam turbine forced air cooling system and method. Background Art

[0002] During the overhaul, minor repair and accident shutdown of nuclear power steam turbines, most nuclear power units currently use natural cooling. The conventional island steam turbine related system maintenance must wait until the high and medium pressure cylinders cool to 120°C, which often takes 4-5 days. If the unit is shut down urgently, the cylinder temperature will be higher, and natural cooling will take 8-9 days to wait for the turbine to cool to the required temperature. The unit availability is reduced and the operating cost of the nuclear power unit is increased. Taking a general million-ton pressurized water reactor nuclear power unit as an example, every day of cooling waiting time reduced will increase the power generation income by about 10 million yuan. Therefore, it is of great economic significance to develop a nuclear power steam turbine cooling system and method.

[0003] Conventional thermal power plants often use sliding parameter shutdown technology, which reduces steam parameters during load reduction, and the cylinder temperature drops accordingly. Since the main steam pressure of the nuclear island of nuclear power turbines is stable, sliding parameter shutdown technology cannot be used. In the process of load reduction shutdown, existing nuclear power units have adopted the method of isolating the heat source of the secondary steam-water separation reheater to increase the cooling rate. This method has positive significance for improving the cooling rate of nuclear power turbines, but for the safety of the equipment, this method has control requirements for the isolation time of the secondary reheat steam source. Therefore, this method has limited effect on improving the cooling efficiency of nuclear power turbines. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a nuclear power steam turbine forced air cooling system and method, which realizes safe, reliable and efficient rapid cooling, saves nuclear power steam turbine shutdown time and improves unit availability.

[0005] The invention provides a nuclear power steam turbine forced air cooling system, comprising a steam turbine steam circuit, and also comprising: an air generation and control module, a shaft seal exhaust module,

[0006] The air generation and control module is respectively connected to the high-pressure drain tank, the medium-pressure water pipe, and the medium-pressure steam extraction through a compressed air inlet hose;

[0007] The shaft seal air extraction module is connected to the intermediate air seal.

[0008] In a specific embodiment of the present invention, the air generation and control module includes an air intake pipeline, on which a filter, a compressor, a flow meter, a thermostat, a dryer and a temperature and pressure gauge are sequentially arranged.

[0009] The air intake pipeline is connected to three branch pipelines respectively, a regulating valve and a flow meter are arranged at the front end of each branch pipeline, and each branch pipeline is connected to various parts of the steam turbine unit through a compressed air inlet hose.

[0010] In a specific embodiment of the present invention, the shaft seal exhaust module includes an exhaust fan, an exhaust fan inlet regulating valve and an exhaust fan inlet hose;

[0011] The exhaust fan is connected to the middle air seal through the exhaust fan inlet hose.

[0012] The exhaust fan inlet hose is provided with an exhaust fan inlet regulating valve.

[0013] In a specific embodiment of the present invention, the air generation and control module is connected to the high-pressure drain tank through a compressed air inlet hose, the high-pressure drain tank is connected to the high-pressure part of the steam turbine through an upper water pipe, and is connected to the low-pressure cylinder through a reheat pipe cold pipe section, a steam-water separation reheater, and a condenser;

[0014] The air generation and control module is connected to the medium-pressure drain pipe through a compressed air inlet hose, the medium-pressure drain pipe is connected to the medium-pressure part of the steam turbine, and the medium-pressure part of the steam turbine is connected to the low-pressure cylinder;

[0015] The air generation and control module is connected to the medium-pressure extraction steam through a compressed air inlet hose, the medium-pressure extraction steam is connected to the medium-pressure part of the steam turbine, and the medium-pressure part of the steam turbine is connected to the low-pressure cylinder.

[0016] In a specific embodiment of the present invention, a cold section of a reheat pipe is provided between the steam-water separation reheater and the exhaust steam of the high-pressure part of the steam turbine, and a hot section of a reheat pipe is provided between the steam-water separation reheater and the inlet steam of the medium-pressure part of the steam turbine; a reheat butterfly valve is provided on the hot section of the reheat pipe after the steam-water separation reheater.

[0017] The present invention provides a method for forced air cooling of a nuclear power steam turbine, comprising the following steps:

[0018] Step S1: after the steam turbine breaks the vacuum, confirm that the state of the steam turbine meets the input conditions of the nuclear power steam turbine forced air cooling system according to any one of claims 1 to 5;

[0019] Step S2: Turn on the exhaust fan, put the air generation and control module into operation, control the air flow to a preset value, and control the air temperature and pressure to the preset values;

[0020] Controlling air to enter the steam turbine at a preset flow rate, the air running flow path includes a high-pressure flow path, a first medium-pressure flow path and a second medium-pressure flow path, and the shaft seal exhaust module exhausts air in the steam turbine;

[0021] Step S3: Rapidly cool the steam turbine through air circulation.

[0022] In a specific embodiment of the present invention, the input conditions include: the steam turbine is in a normal cranking state, there are no abnormal faults in the shaft system and the cylinder, and each system is within a reasonable range; confirm that the steam turbine unit has been shut down, the high-pressure air intake valve and the reheat butterfly valve are in a closed state, the steam turbine rotor has idled to the cranking speed, and maintains the cranking state; the exhaust valve is closed; the steam turbine body and each steam trap on the pipeline are in an open state; the low-pressure cylinder manhole is open.

[0023] In a specific embodiment of the present invention, in step S2, the high-pressure flow path is air entering the compressed air inlet hose from the air generation and control module, passing through the lower high-pressure drain pipe, the high-pressure drain tank, the upper high-pressure drain pipe, the high-pressure main steam pipe, the high-pressure part of the steam turbine, the cold pipe section of the reheat pipe, the steam-water separation reheater, and the condenser into the low-pressure cylinder;

[0024] The first medium-pressure flow path is for air to enter the compressed air inlet hose from the air generation and control module, through the medium-pressure drain pipe, the medium-pressure part of the steam turbine, and enter the low-pressure cylinder;

[0025] The second medium-pressure flow path is for air to enter the compressed air inlet hose from the air generation and control module, through the medium-pressure front steam extraction pipe water pipe, medium-pressure steam extraction, the medium-pressure part of the steam turbine, and enter the low-pressure cylinder;

[0026] The shaft seal exhaust module exhausts the air in the steam turbine through an exhaust fan and then discharges it into the atmosphere.

[0027] In a specific embodiment of the present invention, in step S2, the corresponding temperature measuring points of the steam turbine cylinder are continuously monitored to control the cooling rate of the steam turbine within a preset cooling range;

[0028] The cranking device is always in operation and the cranking current is continuously monitored;

[0029] Closely monitor rotor eccentricity, rotor expansion, cylinder expansion, shaft displacement, turbine speed, lubricating oil inlet temperature, lubricating oil return temperature, bearing temperature, and thrust bearing temperature.

[0030] In a specific embodiment of the present invention, the preset cooling range includes:

[0031] The average cylinder temperature will be within 2℃ / h, and the temperature difference between the upper and lower cylinders will be controlled within 30℃.

[0032] Compared with the prior art, the nuclear power steam turbine forced air cooling system and method of the present invention has the following beneficial effects:

[0033] (1) Ensure safety performance

[0034] The temperature field, strength and deformation of the turbine cylinder and rotor components during the forced air cooling process are analyzed. During the rapid cooling process, the stress of each component is at a low level, and the stress value is much smaller than the allowable stress of the material, so there is no strength risk; the life loss of each component during the rapid cooling process is very low, and the impact of the rapid cooling process on the life of each component can be ignored; during the rapid cooling process, there is no risk of radial and axial collision between the moving and static components of the high and medium pressure cylinders.

[0035] (2) On the basis of the original equipment, the difficulty of system layout is reduced and the feasibility is enhanced by simply adding on-site piping layout and modular setting.

[0036] (3) Improved cooling efficiency

[0037] By using the principle of forced convection, the cooling process of the steam turbine is accelerated by guiding the flow of cooling medium; efficient cooling of the steam turbine is achieved by optimizing the design of air flow paths and finely controlling air parameters;

[0038] Air is used as the cooling medium, taking advantage of its easy access, good fluidity, not prone to phase change, low specific heat, easy to control, and easy to accelerate. This not only reduces the complexity of the forced air cooling system, but also improves the safety margin of the forced air cooling system.

[0039] Air is sent into the steam turbine in a downstream manner. The air passes through the steam turbine along the flow path of the steam, making the temperature distribution inside the steam turbine more uniform, reducing the temperature difference between different parts, reducing thermal stress, and improving safety;

[0040] The system structure design of three steam inlets and one air extraction fully considers the temperature drop rate of each component during the turbine cooling process. Three air injection points and one air extraction point are set on the high-pressure cylinder and the medium-pressure cylinder to maximize the uniformity and efficiency of turbine cooling.

[0041] (4) The method and system of the present invention can significantly reduce the downtime waiting time, improve the efficiency of planned downtime maintenance, reduce the economic losses caused by unplanned downtime, and improve the availability and economic benefits of nuclear power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram showing the structure of a nuclear power steam turbine forced air cooling system of the present invention;

[0043] Figure 2 It shows the cooling temperature variation diagram of different flow schemes;

[0044] In the figure,

[0045] 1-high-pressure drain pipe, 2-high-pressure drain tank, 3-high-pressure main steam pipe, 4-high-pressure part of steam turbine, 5-steam-water separation reheater, 6-condenser, 7-high-pressure steam inlet valve, 8-medium-pressure drain pipe, 9-hot pipe section of reheat pipe, 10-cold pipe section of reheat pipe, 11-reheat butterfly valve, 12-medium-pressure part of steam turbine, 13-medium-pressure extraction steam, 14-intermediate steam seal, 15-air generation and control module, 16-flow meter, 17-temperature and pressure gauge, 18-dryer, 19-temperature changer, 20-compressor, 21-filter, 22-regulating valve, 23-compressed air inlet hose, 24-exhaust fan, 25-exhaust fan inlet regulating valve, 26-exhaust fan inlet hose. DETAILED DESCRIPTION

[0046] In order to further understand the present invention, the embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the present invention.

[0047] The technical solution of the present invention removes heat through the flow of air in the steam turbine to achieve rapid cooling.

[0048] The embodiment of the present invention discloses a nuclear power steam turbine forced air cooling system, including a steam turbine steam circuit, such as Figure 1 As shown, it also includes: an air generation and control module 15, a shaft seal exhaust module,

[0049] The air generation and control module 15 is connected to the high-pressure steam trap 2, the medium-pressure water pipe 8, and the medium-pressure steam extraction 13 respectively through the compressed air inlet hose 23;

[0050] The air generation and control module 15 is a unitized design, including an air intake pipeline, on which a filter 21, a compressor 20, a flow meter 16, a thermostat 19, a dryer 18 and a temperature and pressure gauge 17 are sequentially arranged;

[0051] The compressor 20 provides a stable air source, the filter 21 maintains the cleanliness of the air, the thermostat 19 controls the temperature of the air entering the cylinder, and the dryer 18 ensures the dew point of the air.

[0052] The temperature changer 19 may be a cooler or a heater to adjust the temperature of the air.

[0053] The air generation and control module 15 is movable, and multiple units can share one set of equipment. The air generation and control module 15 is connected to the steam turbine equipment through a detachable interface.

[0054] In order to ensure that the air generation and control module 15 can be quickly connected to the steam turbine unit, air interfaces are provided on the high-pressure steam inlet drain pipe 1, the medium-pressure drain pipe 8, and the medium-pressure steam extraction drain pipe 13.

[0055] Clean compressed air with a temperature and pressure that meet the system requirements is generated by the air generation and control module 15, and the compressed air enters the steam turbine through the compressed air inlet hose 23.

[0056] The air intake pipeline is connected to three branch pipelines respectively. A regulating valve 22 and a flow meter 16 are provided at the front end of each branch pipeline. Each branch pipeline is connected to various parts of the steam turbine unit through a compressed air inlet hose 23.

[0057] The first branch pipeline is a high-pressure flow path, the air generation and control module 15 is connected to the high-pressure drain tank 2 through the compressed air inlet hose 23, the high-pressure drain tank 2 is connected to the high-pressure part 4 of the steam turbine through the upper water pipe 1, and is connected to the low-pressure cylinder through the reheat pipe cold pipe section 10, the steam-water separation reheater 5, and the condenser 6;

[0058] The second branch pipeline is a first medium-pressure flow path, the air generation and control module 15 is connected to the medium-pressure drain pipe 8 through a compressed air inlet hose 23, the medium-pressure drain pipe 8 is connected to the steam turbine medium-pressure part 12, and the steam turbine medium-pressure part 12 is connected to the low-pressure cylinder;

[0059] The third branch pipeline is a second medium-pressure flow path, and the air generation and control module 15 is connected to the medium-pressure extraction steam 13 through a compressed air inlet hose 23, the medium-pressure extraction steam 13 is connected to the medium-pressure part 12 of the turbine, and the medium-pressure part 12 of the turbine is connected to the low-pressure cylinder.

[0060] A reheat pipe cold section 10 is provided between the steam-water separation reheater 5 and the exhaust steam of the high-pressure part 4 of the steam turbine, and a reheat pipe hot section 9 is provided between the steam-water separation reheater 5 and the steam inlet of the medium-pressure part 12 of the steam turbine; a reheat butterfly valve 11 is provided on the reheat pipe hot section 9 after the steam-water separation reheater 5.

[0061] The shaft seal exhaust module is connected to the intermediate gas seal 14 .

[0062] An exhaust is arranged at the turbine shaft seal position to improve the heat dissipation efficiency between the turbine high-pressure part 4 and the middle part of the turbine medium-pressure part 12, which is beneficial to reducing the temperature gradient and improving thermal stress and heat dissipation efficiency.

[0063] The shaft seal exhaust module includes an exhaust fan 24, an exhaust fan inlet regulating valve 25 and an exhaust fan inlet hose 26;

[0064] The exhaust fan 24 is connected to the middle air seal 14 via an exhaust fan inlet hose 26.

[0065] The exhaust fan inlet hose 26 is provided with an exhaust fan inlet regulating valve 25 .

[0066] The embodiment of the present invention also discloses a method for forced air cooling of a nuclear power steam turbine, comprising the following steps:

[0067] Step S1: after the steam turbine breaks the vacuum, confirm that the state of the steam turbine meets the input conditions of the nuclear power steam turbine forced air cooling system described in the above technical solution;

[0068] The startup conditions include: the steam turbine is in normal cranking state, there are no abnormal faults in the shaft system and cylinder, and all systems are within a reasonable range; confirm that the steam turbine unit has been shut down, the high-pressure air inlet valve and reheat butterfly valve are in the closed state, the steam turbine rotor has idled to the cranking speed and maintains the cranking state; the exhaust valve is closed; the steam turbine body and all drain valves on the pipeline are in the open state; the low-pressure cylinder manhole is open.

[0069] Step S2: Turn on the exhaust fan, put the air generation and control module into operation, control the air flow to a preset value, and control the air temperature and pressure to the preset values;

[0070] Specifically:

[0071] Controlling air to enter the steam turbine at a preset flow rate, the air running flow path includes a high-pressure flow path, a first medium-pressure flow path and a second medium-pressure flow path, and the shaft seal exhaust module exhausts air in the steam turbine;

[0072] The high-pressure flow path is that air enters the compressed air inlet hose 23 from the air generation and control module 15, passes through the lower high-pressure drain pipe 1, the high-pressure drain tank 2, the upper high-pressure drain pipe 1, the high-pressure main steam pipe 3, the high-pressure part of the steam turbine 4, the reheat pipe cold pipe section 10, the steam-water separation reheater 5, and the condenser 6 into the low-pressure cylinder;

[0073] The first medium-pressure flow path is for air to enter the compressed air inlet hose 23 from the air generation and control module 15, pass through the medium-pressure drain pipe 8, the medium-pressure part 12 of the steam turbine, and enter the low-pressure cylinder;

[0074] The second medium-pressure flow path is for air to enter the compressed air inlet hose 23 from the air generation and control module 15, through the medium-pressure front extraction pipe water pipe, the medium-pressure extraction steam 13, the medium-pressure part 12 of the steam turbine, and enter the low-pressure cylinder;

[0075] Preferably, if Figure 2 As shown in the figure, the air flow distribution ratio of the high-pressure flow path, the first medium-pressure flow path and the second medium-pressure flow path is 33% / 33% / 33%, which is the most economical air ratio. In addition, the heat capacity of the intermediate steam seal position of the high- and medium-pressure cylinder structure of the steam turbine is large, and it is the slowest cooling area. Whether there is cooling air flowing through the bridge steam seal has a great influence on the cooling effect. The exhaust fan 24 at the intermediate steam seal maintains a flow rate of 40Nm 3 / h.

[0076] The shaft seal exhaust module exhausts the air in the steam turbine through an exhaust fan and then discharges it into the atmosphere.

[0077] During the commissioning of the steam turbine forced air cooling system, the corresponding temperature measurement points of the steam turbine cylinder are continuously monitored to control the cooling rate of the steam turbine within the preset cooling range; the preset cooling range includes: the average cooling rate of the cylinder is within 2℃ / h, and the temperature difference between the upper and lower cylinders is controlled within 30℃. When the cooling rate of the steam turbine is too fast or too slow, adjust the valve of the flow control device to control the cooling rate.

[0078] During the commissioning of the steam turbine forced air cooling system, the cranking device is always in operation and the cranking current is continuously monitored;

[0079] During the commissioning of the steam turbine forced air cooling system, closely monitor the rotor eccentricity, rotor expansion, cylinder expansion, shaft displacement, turbine speed, lubricating oil inlet temperature, lubricating oil return temperature, bearing temperature, and thrust bearing temperature.

[0080] Step S3: Rapidly cool the steam turbine through air circulation.

[0081] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0082] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A nuclear power steam turbine forced air cooling system, comprising a steam turbine steam circuit, characterized in that: Also includes: Air generation and control module, shaft seal exhaust module, The air generation and control module is respectively connected to the high-pressure drain tank, the medium-pressure water pipe, and the medium-pressure steam extraction through a compressed air inlet hose; The shaft seal air extraction module is connected to the intermediate air seal.

2. The nuclear power steam turbine forced air cooling system according to claim 1, characterized in that: The air generation and control module includes an air intake pipeline, on which a filter, a compressor, a flow meter, a temperature changer, a dryer and a temperature and pressure gauge are sequentially arranged. The air intake pipeline is connected to three branch pipelines respectively, a regulating valve and a flow meter are arranged at the front end of each branch pipeline, and each branch pipeline is connected to various parts of the steam turbine unit through a compressed air inlet hose.

3. The nuclear power steam turbine forced air cooling system according to claim 1, characterized in that: The shaft seal exhaust module includes an exhaust fan, an exhaust fan inlet regulating valve and an exhaust fan inlet hose; The exhaust fan is connected to the middle air seal through the exhaust fan inlet hose. The exhaust fan inlet hose is provided with an exhaust fan inlet regulating valve.

4. The nuclear power steam turbine forced air cooling system according to claim 1, characterized in that: The air generation and control module is connected to the high-pressure drain tank through a compressed air inlet hose, and the high-pressure drain tank is connected to the high-pressure part of the steam turbine through an upper water pipe, and is connected to the low-pressure cylinder through a reheat pipe cold pipe section, a steam-water separation reheater, and a condenser; The air generation and control module is connected to the medium-pressure drain pipe through a compressed air inlet hose, the medium-pressure drain pipe is connected to the medium-pressure part of the steam turbine, and the medium-pressure part of the steam turbine is connected to the low-pressure cylinder; The air generation and control module is connected to the medium-pressure extraction steam through a compressed air inlet hose, the medium-pressure extraction steam is connected to the medium-pressure part of the steam turbine, and the medium-pressure part of the steam turbine is connected to the low-pressure cylinder.

5. The nuclear power steam turbine forced air cooling system according to claim 4, characterized in that: A reheat pipe cold section is provided between the steam-water separation reheater and the exhaust steam of the high-pressure part of the steam turbine, and a reheat pipe hot section is provided between the steam-water separation reheater and the steam inlet of the medium-pressure part of the steam turbine; a reheat butterfly valve is provided on the reheat pipe hot section after the steam-water separation reheater.

6. A method for forced air cooling of a nuclear power steam turbine, characterized in that: The following steps are involved: Step S1: after the steam turbine breaks vacuum, confirm that the state of the steam turbine meets the input conditions of the nuclear power steam turbine forced air cooling system according to any one of claims 1 to 5; Step S2: Turn on the exhaust fan, put the air generation and control module into operation, control the air flow to a preset value, and control the air temperature and pressure to the preset values; Controlling air to enter the steam turbine at a preset flow rate, the air running flow path includes a high-pressure flow path, a first medium-pressure flow path and a second medium-pressure flow path, and the shaft seal exhaust module exhausts air in the steam turbine; Step S3: Rapidly cool the steam turbine through air circulation.

7. The method for forced air cooling of a nuclear power steam turbine according to claim 6, characterized in that: The startup conditions include: the steam turbine is in normal cranking state, there are no abnormal faults in the shaft system and cylinder, and all systems are within a reasonable range; confirm that the steam turbine unit has been shut down, the high-pressure air inlet valve and reheat butterfly valve are in the closed state, the steam turbine rotor has idled to the cranking speed and maintains the cranking state; the exhaust valve is closed; the steam turbine body and all drain valves on the pipeline are in the open state; the low-pressure cylinder manhole is open.

8. The method for forced air cooling of a nuclear power steam turbine according to claim 6, characterized in that: In the step S2, the high-pressure flow path is air entering the compressed air inlet hose from the air generation and control module, passing through the lower high-pressure drain pipe, the high-pressure drain tank, the upper high-pressure drain pipe, the high-pressure main steam pipe, the high-pressure part of the steam turbine, the cold pipe section of the reheat pipe, the steam-water separation reheater, and the condenser into the low-pressure cylinder; The first medium-pressure flow path is for air to enter the compressed air inlet hose from the air generation and control module, through the medium-pressure drain pipe, the medium-pressure part of the steam turbine, and enter the low-pressure cylinder; The second medium-pressure flow path is for air to enter the compressed air inlet hose from the air generation and control module, through the medium-pressure front steam extraction pipe water pipe, medium-pressure steam extraction, the medium-pressure part of the steam turbine, and enter the low-pressure cylinder; The shaft seal exhaust module exhausts the air in the steam turbine through an exhaust fan and then discharges it into the atmosphere.

9. The method for forced air cooling of a nuclear power steam turbine according to claim 6, characterized in that: In the step S2, the corresponding temperature measuring points of the steam turbine cylinder are continuously monitored to control the cooling rate of the steam turbine within a preset cooling range; The cranking device is always in operation and the cranking current is continuously monitored; Closely monitor rotor eccentricity, rotor expansion, cylinder expansion, shaft displacement, turbine speed, lubricating oil inlet temperature, lubricating oil return temperature, bearing temperature, and thrust bearing temperature.

10. The method for forced air cooling of a nuclear power steam turbine according to claim 9, characterized in that: The preset cooling range includes: The average cylinder temperature will be within 2℃ / h, and the temperature difference between the upper and lower cylinders will be controlled within 30℃.

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