Sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system

Abstract

The invention particularly relates to a sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system, which belongs to the technical field of control, and comprises a shaft seal steam supply temperature sensor, a steam supply temperature control module, a steam supply temperature control module and a steam supply temperature control module, the shaft seal steam supply temperature judgment module is used for judging the shaft seal steam supply temperature measured value to obtain a shaft seal steam supply temperature judgment result; the shaft seal steam supply temperature setting module is used for manually or automatically setting a shaft seal steam supply temperature set value according to the shaft seal steam supply temperature judgment result; the PID controller is used for calculating a first desuperheating water valve opening set value; and the desuperheating water valve adjusts the opening degree of the desuperheating water valve according to the first desuperheating water valve opening degree set value. The steam supply temperature of the steam turbine shaft seal is automatically adjusted, it is ensured that the steam supply temperature of the steam turbine shaft seal is matched with the temperature of a steam turbine rotor, the steam turbine rotor is protected, and the service life of the steam turbine rotor is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of system and equipment control, and particularly to a steam supply temperature control system for the shaft seal of a sodium-cooled fast reactor steam turbine. Background Art

[0002] See Figure 1 , the steam supply system for the shaft seal of a sodium-cooled fast reactor steam turbine includes a shaft seal steam supply system and a shaft seal steam supply pipeline. The shaft seal steam supply system is connected to the shaft seal chamber of the steam turbine through the shaft seal steam supply pipeline, and the steam in the shaft seal steam supply system is sent to the shaft seal chamber of the steam turbine through the shaft seal steam supply pipeline. A desuperheating water valve and a shaft seal steam supply temperature sensor are provided on the shaft seal steam supply pipeline. The desuperheating water valve is used to control the amount of desuperheating water entering the shaft seal steam supply pipeline and adjust the temperature of the shaft seal steam supply; when the desuperheating water valve is opened wider, more desuperheating water enters the shaft seal steam supply pipeline and mixes with the high-temperature steam to reduce the temperature of the shaft seal steam supply; conversely, when the desuperheating water valve is closed smaller, the amount of desuperheating water entering the shaft seal steam supply pipeline decreases, and the temperature of the shaft seal steam supply increases. The shaft seal steam supply temperature sensor is used to measure the temperature of the shaft seal steam supply.

[0003] The control logic of the existing shaft seal steam supply temperature control system for the shaft seal steam supply temperature is as follows: the shaft seal steam supply temperature sensor measures the shaft seal steam supply temperature in real time and transmits the analog signal of the shaft seal steam supply temperature to the shaft seal steam supply temperature control system. The shaft seal steam supply temperature control system controls the opening of the desuperheating water valve according to the deviation between the set value and the actual value of the shaft seal steam supply temperature through a PID controller, thereby controlling the desuperheating water flow rate, realizing the adjustment of the shaft seal steam supply temperature, steadily eliminating the deviation between the actual value and the set value of the shaft seal steam supply temperature, and realizing the automatic control of the shaft seal steam supply temperature.

[0004] The original shaft seal steam supply temperature control system cannot automatically adjust the matching between the shaft seal steam supply temperature and the temperature of the steam turbine rotor, which easily causes the steam turbine rotor to deform and generate noise due to the temperature difference, damages the steam turbine rotor, and affects the service life of the steam turbine rotor. Summary of the Invention

[0005] The purpose of the present invention is to provide a steam supply temperature control system for the shaft seal of a sodium-cooled fast reactor steam turbine, which realizes the automatic adjustment of the steam supply temperature of the shaft seal of the steam turbine, ensures the matching between the steam supply temperature of the shaft seal of the steam turbine and the temperature of the steam turbine rotor, protects the steam turbine rotor, and improves the service life of the steam turbine rotor.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A steam supply temperature control system for the shaft seal of a sodium-cooled fast reactor steam turbine, comprising:

[0008] A shaft seal steam supply temperature sensor, installed on the shaft seal steam supply pipeline, for obtaining the measured value of the shaft seal steam supply temperature and sending it to the shaft seal steam supply temperature judgment module and the PID controller;

[0009] The gland steam temperature judgment module is used to receive the measured gland steam temperature value sent by the gland steam temperature sensor; judge the measured gland steam temperature value to obtain the gland steam temperature judgment result and send it to the gland steam temperature setting module;

[0010] The gland steam temperature setting module is used to receive the gland steam temperature judgment result sent by the gland steam temperature judgment module; manually or automatically set the gland steam temperature setting value; send the manually or automatically set gland steam temperature setting value to the PID controller according to the gland steam temperature judgment result;

[0011] The PID controller is used to receive the gland steam temperature setting value sent by the gland steam temperature setting module and the measured gland steam temperature value sent by the gland steam temperature sensor; calculate the set value of the first desuperheating water valve opening according to the difference between the gland steam temperature setting value and the measured gland steam temperature value; send the set value of the first desuperheating water valve opening to the desuperheating water valve;

[0012] The desuperheating water valve receives the set value of the first desuperheating water valve opening sent by the PID controller and adjusts its own valve opening according to the set value of the first desuperheating water valve opening.

[0013] As one possible implementation, the gland steam temperature judgment result includes that the measured gland steam temperature value > 220 °C, 180 °C ≤ the measured gland steam temperature value ≤ 220 °C, and the measured gland steam temperature value < 180 °C.

[0014] As one possible implementation, the gland steam temperature control system of the sodium-cooled fast reactor steam turbine further includes a valve operation module;

[0015] The gland steam temperature judgment module is also used to send the gland steam temperature judgment result to the valve operation module;

[0016] The valve operation module is used to manually set the set value of the second desuperheating water valve opening; receive the measured gland steam temperature value judgment result sent by the gland steam temperature judgment module; when the measured gland steam temperature value > 220 °C, do not send the set value of the second desuperheating water valve opening to the desuperheating water valve; when the measured gland steam temperature value ≤ 220 °C, send the set value of the second desuperheating water valve opening to the desuperheating water valve;

[0017] The desuperheating water valve receives the set value of the second desuperheating water valve opening sent by the valve operation module and adjusts its own valve opening according to the set value of the second desuperheating water valve opening.

[0018] As one of the realizable ways, the gland steam temperature setting module is used to automatically set the gland steam temperature setting value to 200°C and send the automatically set gland steam temperature setting value to the PID controller when the measured gland steam temperature > 220°C; when the measured gland steam temperature ≤ 220°C, manually set the gland steam temperature setting value and send the manually set gland steam temperature setting value to the PID controller.

[0019] As one of the realizable ways, the gland steam temperature judgment module is also used to send the gland steam temperature judgment result to the PID controller;

[0020] The PID controller is also used to receive the gland steam temperature judgment result sent by the gland steam temperature judgment module; when the measured gland steam temperature < 180°C, close the desuperheating water valve and track the measured gland steam temperature.

[0021] As one of the realizable ways, the PID controller is also used to track the opening degree of the desuperheating water valve.

[0022] As one of the realizable ways, the PID controller sets the opening degree setting value of the desuperheating water valve ≥ 30%; when the opening degree setting value of the first desuperheating water valve or the second desuperheating water valve < 30%, the PID controller sends the opening degree setting value of the third desuperheating water valve to the desuperheating water valve; the opening degree setting value of the third desuperheating water valve = 30%.

[0023] The beneficial technical effects of the present invention:

[0024] The gland steam temperature control system of the sodium-cooled fast reactor steam turbine of the present invention monitors and judges the gland steam temperature; when the gland steam temperature deviates from the required value, automatically adjusts the opening degree of the desuperheating water valve, adjusts the gland steam temperature, maintains the stability of the gland steam temperature, prevents the temperature difference between the gland steam temperature and the steam turbine rotor temperature from being too high, causing deformation of the steam turbine rotor and resulting in steam turbine vibration, and maintains the stability and reliability of the operation of the steam turbine unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural view of an embodiment of the gland steam supply system of the sodium-cooled fast reactor steam turbine;

[0026] Figure 2 It is a schematic structural view of an embodiment of the gland steam temperature control system of the sodium-cooled fast reactor steam turbine of the present invention.

[0027] In the figure, 1. gland steam supply pipeline; 2. steam turbine gland chamber; 3. gland steam temperature sensor; 4. low-pressure cylinder of the steam turbine. DETAILED DESCRIPTION OF THE INVENTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "provided with" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", "third", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0030] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0031] See Figure 2 , this embodiment provides a sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system, including:

[0032] A shaft seal steam supply temperature sensor, installed on the shaft seal steam supply pipeline, for obtaining the measured value of the shaft seal steam supply temperature and sending it to the shaft seal steam supply temperature judgment module and the PID controller;

[0033] A shaft seal steam supply temperature judgment module, for receiving the measured value of the shaft seal steam supply temperature sent by the shaft seal steam supply temperature sensor; judging the measured value of the shaft seal steam supply temperature to obtain a shaft seal steam supply temperature judgment result and sending it to the shaft seal steam supply temperature setting module;

[0034] A shaft seal steam supply temperature setting module, for receiving the shaft seal steam supply temperature judgment result sent by the shaft seal steam supply temperature judgment module; manually or automatically setting the shaft seal steam supply temperature setting value; sending the manually or automatically set shaft seal steam supply temperature setting value to the PID controller according to the shaft seal steam supply temperature judgment result;

[0035] A PID controller, for receiving the shaft seal steam supply temperature setting value sent by the shaft seal steam supply temperature setting module and the measured value of the shaft seal steam supply temperature sent by the shaft seal steam supply temperature sensor; calculating the opening setting value of the first desuperheating water valve according to the difference between the shaft seal steam supply temperature setting value and the measured value of the shaft seal steam supply temperature; sending the opening setting of the first desuperheating water valve to the desuperheating water valve;

[0036] The desuperheating water valve receives the first desuperheating water valve opening set value sent by the PID controller and adjusts its own valve opening according to the first desuperheating water valve opening set value.

[0037] In this embodiment, as one of the feasible ways, the judgment result of the gland steam temperature includes that the measured value of the gland steam temperature > 220 °C, 180 °C ≤ the measured value of the gland steam temperature ≤ 220 °C, and the measured value of the gland steam temperature < 180 °C.

[0038] In this embodiment, as one of the feasible ways, the gland steam temperature control system of the sodium-cooled fast reactor steam turbine further includes a valve operation module;

[0039] The gland steam temperature judgment module is further configured to send the gland steam temperature judgment result to the valve operation module;

[0040] The valve operation module is used to manually set the second desuperheating water valve opening set value; receive the measured value judgment result of the gland steam temperature sent by the gland steam temperature judgment module; when the measured value of the gland steam temperature > 220 °C, do not send the second desuperheating water valve opening set value to the desuperheating water valve; when the measured value of the gland steam temperature ≤ 220 °C, send the second desuperheating water valve opening set value to the desuperheating water valve;

[0041] The desuperheating water valve receives the second desuperheating water valve opening set value sent by the valve operation module and adjusts its own valve opening according to the second desuperheating water valve opening set value.

[0042] The valve operation module is used for the operator to intervene and operate the valve under special working conditions.

[0043] In this embodiment, as one of the feasible ways, the gland steam temperature setting module is used to automatically set the gland steam temperature set value to 200 °C and send the automatically set gland steam temperature set value to the PID controller when the measured value of the gland steam temperature > 220 °C; manually set the gland steam temperature set value and send the manually set gland steam temperature set value to the PID controller when the measured value of the gland steam temperature ≤ 220 °C.

[0044] In this embodiment, as one of the feasible ways, the gland steam temperature judgment module is further configured to send the gland steam temperature judgment result to the PID controller;

[0045] The PID controller is further configured to receive the gland steam temperature judgment result sent by the gland steam temperature judgment module; when the measured value of the gland steam temperature < 180 °C, close the desuperheating water valve and track the measured value of the gland steam temperature.

[0046] In this embodiment, as one of the feasible ways, the PID controller is further configured to track the desuperheating water valve opening.

[0047] In this embodiment, as one of the achievable ways, in the automatic control mode, the set value of the opening of the desuperheating water valve set by the PID controller is ≥ 30%; when the set value of the opening of the first desuperheating water valve < 30%, the PID controller sends the set value of the opening of the third desuperheating water valve to the desuperheating water valve; the set value of the opening of the third desuperheating water valve = 30%.

[0048] Because the opening of the desuperheating water valve for controlling the gland steam supply temperature is small, there is no flow when the opening of the desuperheating water valve is less than 30%. Therefore, in the automatic control mode, the PID controller sets the set value of the opening of the desuperheating water valve to be not less than 30%.

[0049] The PID controller calculates the set value of the opening of the desuperheating water valve using the following transfer function:

[0050] G(s) = (U(s)) / (E(s)) = KP × (1 + 1 / (TI × s) + (TD × s) / (1 + TD / KD × s))

[0051] Among them, KP is the proportional gain, which determines the strength of the proportional control; the proportional control directly generates the control quantity according to the magnitude of the error signal. The larger the proportional gain, the stronger the control action, but it may lead to a steady-state error;

[0052] TI is the integral time constant, which determines the strength of the integral control; the integral control uses the integral of the error signal over time as the control quantity to eliminate the steady-state error, but too strong integral action may lead to an increase in the overshoot and even cause system oscillation;

[0053] TD is the derivative time constant, which determines the strength of the derivative control; the derivative control generates the control quantity according to the change trend of the error signal to improve the dynamic performance of the system, but too strong derivative action may make the system sensitive to noise;

[0054] KD is the derivative gain;

[0055] U(s) is the Laplace transform of the controller output, representing the control quantity calculated by the controller according to the error signal;

[0056] E(s) is the Laplace transform of the error signal, that is, the difference between the set value and the actual value.

[0057] The transfer function is used to describe the relationship between the controller output and the input error. In an automatic control system, the PID controller controls the output of the system by adjusting three parameters: proportional (KP), integral (TI), and derivative (KD) to achieve a stable, fast, and accurate control effect.

[0058] The steam seal supply temperature control system of the sodium-cooled fast reactor turbine of the present invention monitors and judges the steam seal supply temperature; when the steam seal supply temperature deviates from the required value, it automatically adjusts the opening of the desuperheating water valve to adjust the steam seal supply temperature, maintain the stability of the steam seal supply temperature, prevent the temperature difference between the steam seal supply temperature and the turbine rotor temperature from being too high, cause deformation of the turbine rotor and lead to turbine vibration, and maintain the stability and reliability of the operation of the steam turbine unit.

[0059] The above embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the appended claims.

Claims

1. A sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system, characterized in that Including: A gland steam temperature sensor, installed on the gland steam supply pipeline, for obtaining the measured value of the gland steam temperature and sending it to the gland steam temperature judgment module and the PID controller; A gland steam temperature judgment module, for receiving the measured value of the gland steam temperature sent by the gland steam temperature sensor; judging the measured value of the gland steam temperature to obtain a gland steam temperature judgment result and sending it to the gland steam temperature setting module; A gland steam temperature setting module, for receiving the gland steam temperature judgment result sent by the gland steam temperature judgment module; manually or automatically setting the gland steam temperature setting value; sending the manually or automatically set gland steam temperature setting value to the PID controller according to the gland steam temperature judgment result; A PID controller, for receiving the gland steam temperature setting value sent by the gland steam temperature setting module and the measured value of the gland steam temperature sent by the gland steam temperature sensor; calculating the set value of the first desuperheating water valve opening according to the difference between the gland steam temperature setting value and the measured value of the gland steam temperature; sending the set value of the first desuperheating water valve opening to the desuperheating water valve; The desuperheating water valve receives the set value of the first desuperheating water valve opening sent by the PID controller and adjusts its own valve opening according to the set value of the first desuperheating water valve opening.

2. The sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system according to claim 1, characterized in that The gland steam temperature judgment result includes that the measured value of the gland steam temperature > 220 °C, 180 °C ≤ the measured value of the gland steam temperature ≤ 220 °C, and the measured value of the gland steam temperature < 180 °C.

3. The steam supply temperature control system for the shaft seal of the sodium-cooled fast reactor turbine according to claim 2, characterized in that, The gland steam temperature control system of the sodium-cooled fast reactor steam turbine further includes a valve operation module; The gland steam temperature judgment module is also used to send the gland steam temperature judgment result to the valve operation module; The valve operation module is used to manually set the set value of the second desuperheating water valve opening; receive the measured value judgment result of the gland steam temperature sent by the gland steam temperature judgment module; when the measured value of the gland steam temperature > 220 °C, do not send the set value of the second desuperheating water valve opening to the desuperheating water valve; when the measured value of the gland steam temperature ≤ 220 °C, send the set value of the second desuperheating water valve opening to the desuperheating water valve; The desuperheating water valve receives the set value of the second desuperheating water valve opening sent by the valve operation module and adjusts its own valve opening according to the set value of the second desuperheating water valve opening.

4. The sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system according to claim 2, characterized in that, The gland steam temperature setting module is used to automatically set the gland steam temperature setting value to 200 °C and send the automatically set gland steam temperature setting value to the PID controller when the measured value of the gland steam temperature > 220 °C; manually set the gland steam temperature setting value and send the manually set gland steam temperature setting value to the PID controller when the measured value of the gland steam temperature ≤ 220 °C.

5. The sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system according to claim 2, characterized in that, The gland steam temperature judgment module is also used to send the gland steam temperature judgment result to the PID controller; The PID controller is also used to receive the gland steam temperature judgment result sent by the gland steam temperature judgment module; when the measured value of the gland steam temperature < 180 °C, close the desuperheating water valve and track the measured value of the gland steam temperature.

6. The sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system according to claim 2, characterized in that The PID controller is also used to track the opening of the desuperheating water valve.

7. The sodium-cooled fast reactor steam turbine shaft seal steam supply temperature control system according to claim 2, wherein, The set value of the desuperheating water valve opening of the PID controller is ≥ 30%; when the set value of the desuperheating water valve opening < 30%, the set value of the desuperheating water valve opening sent by the PID controller to the desuperheating water valve = 30%.

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