A method and system for controlling lubricating oil temperature of a steam turbine generator set

Abstract

The present invention discloses a method and system for controlling the lubricating oil temperature of a steam turbine generator set, comprising: obtaining a current temperature value of the lubricating oil at a preset location of a target steam turbine generator set; generating a valve control signal for an electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at the circulating water inlet of the oil cooler of the target steam turbine generator set, and the electric valve is used to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set; and transmitting the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to a target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow rate of the target steam turbine generator set. By utilizing a fuzzy control algorithm to control the temperature control loop, the present invention overcomes the difficulty of controlling the time-varying and uncertain lubricating oil temperature during the operation of the steam turbine set.

Description

Technical Field

[0001] The present invention relates to the field of automatic control technology, and in particular to a lubricating oil temperature control method and system for a steam turbine generator set. Background Art

[0002] Oil is an essential working fluid in steam turbine generator sets. The turbine's oil system performs lubrication, control, cooling, and sealing functions, and its proper functioning is essential for the proper operation of the turbine and, ultimately, the entire unit. Circulating water is typically used to cool the lubricating oil in steam turbine generator sets, and lubricating oil temperature is primarily regulated by manually adjusting the opening of the circulating water inlet valve through the oil cooler. If the oil temperature is too low, the lubricating oil viscosity increases, preventing an effective oil film from forming and achieving lubrication, potentially inducing unit vibration and impacting safe operation. If the oil temperature is too high, the lubricating oil viscosity decreases, preventing cooling and effectively dissipating the heat generated by friction between the rotating shaft and the oil film. Currently, most steam turbine lubricating oil temperature control in domestic power plants relies solely on manual adjustment, which not only affects regulation accuracy but also can easily lead to accidents.

[0003] Therefore, it is urgent to provide a technical solution to solve the above technical problems. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method and system for controlling the temperature of lubricating oil of a steam turbine generator set.

[0005] The technical solution of a method for controlling lubricating oil temperature of a steam turbine generator set of the present invention is as follows:

[0006] Obtaining a current temperature value of lubricating oil at a preset position of a target steam turbine generator set;

[0007] generating a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at a circulating water inlet of an oil cooler of the target steam turbine generator set, and is configured to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set;

[0008] The valve control signal is sent to the electric valve, so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set.

[0009] The beneficial effects of the lubricating oil temperature control method of a steam turbine generator set of the present invention are as follows:

[0010] The method of the present invention controls the temperature control loop by adopting a fuzzy control algorithm, thereby overcoming the control difficulties of the time-varying and uncertain temperature of the lubricating oil during the operation of the steam turbine unit.

[0011] On the basis of the above solution, the lubricating oil temperature control method of a steam turbine generator set of the present invention can be further improved as follows.

[0012] Furthermore, the preset position is the oil outlet of the oil cooler, and the step of obtaining the current temperature value of the lubricating oil at the preset position of the target steam turbine generator set includes:

[0013] The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is obtained.

[0014] Furthermore, the step of generating a valve control signal for the electric valve of the target steam turbine generator set based on the fuzzy control algorithm and the current temperature value includes:

[0015] Obtaining a current temperature deviation value according to the current temperature value and the preset temperature value;

[0016] Based on the fuzzy control algorithm and the current temperature deviation value, the valve opening value is generated, and the target valve opening value is converted into the valve control signal.

[0017] Furthermore, the electric valve is provided with an electronic actuator, and the step of sending the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal to achieve control of the circulating water flow of the target steam turbine generator set includes:

[0018] The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

[0019] Furthermore, the target steam turbine generator set is a 15MW steam turbine generator set.

[0020] The technical solution of a lubricating oil temperature control system for a steam turbine generator set of the present invention is as follows:

[0021] Including: acquisition module, processing module and control module;

[0022] The acquisition module is used to: obtain the current temperature value of the lubricating oil at a preset position of the target steam turbine generator set;

[0023] The processing module is configured to generate a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at a circulating water inlet of an oil cooler of the target steam turbine generator set, and is configured to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set;

[0024] The control module is used to send the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set.

[0025] The beneficial effects of the lubricating oil temperature control system of a steam turbine generator set of the present invention are as follows:

[0026] The system of the present invention controls the temperature control loop by adopting a fuzzy control algorithm, thereby overcoming the control difficulties of the time-varying and uncertain temperature of the lubricating oil during the operation of the steam turbine unit.

[0027] On the basis of the above solution, the lubricating oil temperature control system of a steam turbine generator set of the present invention can be further improved as follows.

[0028] Furthermore, the preset position is: the oil outlet of the oil cooler, and the acquisition module is specifically used for:

[0029] The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is obtained.

[0030] Furthermore, the processing module is specifically configured to:

[0031] Obtaining a current temperature deviation value according to the current temperature value and the preset temperature value;

[0032] Based on the fuzzy control algorithm and the current temperature deviation value, the valve opening value is generated, and the target valve opening value is converted into the valve control signal.

[0033] Furthermore, the control module is specifically configured to:

[0034] The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

[0035] Furthermore, the target steam turbine generator set is a 15MW steam turbine generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic flow chart showing an embodiment of a method for controlling lubricating oil temperature of a steam turbine generator set provided by the present invention;

[0037] Figure 2 A schematic diagram showing the control principle of a target steam turbine generator set in an embodiment of a method for controlling lubricating oil temperature of a steam turbine generator set provided by the present invention is shown;

[0038] Figure 3 A schematic flow chart of step 120 in an embodiment of a method for controlling lubricating oil temperature of a steam turbine generator set provided by the present invention is shown;

[0039] Figure 4 A schematic diagram showing the principle of a simulation experiment in an embodiment of a method for controlling lubricating oil temperature of a steam turbine generator set provided by the present invention is shown;

[0040] Figure 5 The figure shows a structural diagram of an embodiment of a lubricating oil temperature control system of a steam turbine generator set provided by the present invention. DETAILED DESCRIPTION

[0041] Figure 1 FIG1 shows a flow chart of an embodiment of a method for controlling lubricating oil temperature of a steam turbine generator set provided by the present invention, which is executed by a controller. Figure 1 As shown, the method includes the following steps:

[0042] Step 110: Acquire the current temperature value of the lubricating oil at a preset position of the target steam turbine generator set.

[0043] ① In this embodiment, the target steam turbine generator set is a 15MW steam turbine generator set. Other types of steam turbine generator sets can also be selected based on demand and are not limited here. ② Current Temperature Value: The lubricating oil temperature at the oil cooler outlet of the target steam turbine generator set at the current moment. ③ Preset Location: Any location within the target steam turbine generator set. In this embodiment, the default location is the oil cooler outlet.

[0044] Specifically, the controller obtains the temperature value of the lubricating oil at a preset position of the 15MW steam turbine generator set at the current moment.

[0045] It should be noted that ① Figure 2 FIG. 1 shows a structural diagram of the lubricating oil temperature control system of the target steam turbine generator set in this embodiment. Figure 2As shown, the system is powered by the main oil pump. Lubricating oil flows through the oil injector into two lower-pressure streams: one stream returns to the main oil pump, and the other stream is cooled in the oil cooler and then directly fed to the bearings. The lubricating oil is cooled by heat exchange in the surface heat exchanger (oil cooler). In this system, a controller controls an electric valve to vary the circulating water flow rate, thereby varying the heat exchange rate to control the oil temperature. The controller in this embodiment can be a chip, processor, or fuzzy controller; it only needs to be able to implement the functionality of this embodiment and is not limited here.

[0046] Step 120: Generate a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value.

[0047] ① The electric valve is disposed at the circulating water inlet of the target steam turbine generator set's oil cooler and is used to control the lubricating oil temperature of the target steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set. ② The valve control signal is an electrical signal that drives the valve opening, and different valve control signals correspond to different valve opening values.

[0048] Specifically, if Figure 3 As shown, step 120 includes:

[0049] Step 121: Obtain a current temperature deviation value according to the current temperature value and the preset temperature value.

[0050] Among them, ① the preset temperature value is the ideal temperature value of the lubricating oil of the target steam turbine generator set set by the controller, and the default is 45°C. ② The current temperature deviation value is the temperature difference between the current temperature value and the preset temperature value.

[0051] Step 122: Based on the fuzzy control algorithm and the current temperature deviation value, generate the valve opening value, and convert the target valve opening value into the valve control signal.

[0052] Among them, ① the fuzzy control algorithm is an intelligent control strategy that reflects human experience and knowledge. When planning and designing a fuzzy control system, there is no need for a mathematical description of the control process. Instead, reliable control performance can be achieved by establishing practical linguistic variable control rules based on the designer's or expert's knowledge, experience, or operational data, starting from the operational understanding of industrial control. ② The fuzzy control algorithm is centered around a fuzzy controller consisting of four components: a rule base, a fuzzy inference algorithm, input variable fuzzification, and output variable clarity. It preprocesses the signals received from sensors and then fuzzifies them, converting them into corresponding fuzzy variables. The fuzzy controller's inference algorithm then generates fuzzy control decisions. After clarity, the fuzzy control values ​​are converted into actual output control values, which are then output to drive actuator action, achieving the purpose of fuzzy control. ③ In the fuzzy control algorithm, the current temperature deviation of the lubricating oil in the target steam turbine generator set is used as input, and the target valve opening value corresponding to the valve control signal is used as output. Therefore, the actual input to the controller is the set temperature deviation value e and the target valve opening value D. The domain of the input variable e is [-6, 6], and the domain of the output variable D is [0, 1]. The rules of the fuzzy controller are determined based on field tests and operational experience, as shown in Table 1 below.

[0053] Table 1:

[0054] Step 130: Sending the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set.

[0055] Preferably, step 110 includes:

[0056] The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is obtained.

[0057] Wherein, the temperature sensor is arranged at the oil outlet of the oil cooler.

[0058] It should be noted that the number of temperature sensors may be one or more. When there are multiple temperature sensors, the average value of the multiple temperature sensors is used as the current temperature value.

[0059] Preferably, the electric valve is provided with an electronic actuator.

[0060] The default electronic actuator is: 381L series linear electronic electric actuator, which can also be selected according to needs. There is no restriction here.

[0061] Step 130 includes:

[0062] The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

[0063] The valve control signal is a DC 4-20mA electrical signal.

[0064] It should be noted that the electronic actuator receives the valve control signal sent by the controller to achieve a predetermined linear reciprocating motion to change the valve core position. The controlled object of the electronic actuator is the position (opening value) of the valve core of the electric valve.

[0065] In addition, using Figure 4 The simulation experiment shown verifies the feasibility of this embodiment.

[0066] Specifically, based on the technical solution of this embodiment, a simulation experiment for controlling the lubricating oil temperature of a target steam turbine generator set was conducted in conjunction with MATLAB's Simulink function. The test results demonstrated that the algorithm accurately controlled the lubricating oil temperature of the target steam turbine generator set at 45°C within 260 seconds, exhibited excellent dynamic and static response, and exhibited strong anti-interference capabilities, effectively resolving the challenge of automatic turbine oil temperature control.

[0067] The technical solution of this embodiment overcomes the difficulty of controlling the time-varying and uncertain temperature of the lubricating oil during the operation of the steam turbine unit by using a fuzzy control algorithm to control the temperature control loop.

[0068] Figure 5 FIG1 shows a schematic structural diagram of an embodiment of a lubricating oil temperature control system for a steam turbine generator set provided by the present invention. Figure 5 As shown, the system 200 includes: a collection module 210 , a processing module 220 and a control module 230 .

[0069] The acquisition module 210 is used to: obtain the current temperature value of the lubricating oil at a preset position of the target steam turbine generator set;

[0070] The processing module 220 is configured to generate a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at a circulating water inlet of an oil cooler of the target steam turbine generator set, and is configured to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set;

[0071] The control module 230 is used to send the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set.

[0072] Preferably, the preset position is: the oil outlet of the oil cooler, and the acquisition module 210 is specifically used for:

[0073] The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is obtained.

[0074] Preferably, the processing module 220 is specifically configured to:

[0075] Obtaining a current temperature deviation value according to the current temperature value and the preset temperature value;

[0076] Based on the fuzzy control algorithm and the current temperature deviation value, the valve opening value is generated, and the target valve opening value is converted into the valve control signal.

[0077] Preferably, the control module 230 is specifically configured to:

[0078] The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

[0079] Preferably, the target steam turbine generator set is a 15MW steam turbine generator set.

[0080] The technical solution of this embodiment overcomes the difficulty of controlling the time-varying and uncertain temperature of the lubricating oil during the operation of the steam turbine unit by using a fuzzy control algorithm to control the temperature control loop.

[0081] The above-mentioned parameters and steps for each module to implement corresponding functions in the lubricating oil temperature control system 200 of a steam turbine generator set in this embodiment can refer to the parameters and steps in the implementation of the lubricating oil temperature control method of a steam turbine generator set above, and will not be repeated here.

[0082] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the present invention may be practiced without these specific details. Similarly, in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. The claims that follow the detailed description are hereby expressly incorporated into that detailed description, with each claim itself serving as a separate embodiment of the present invention.

[0083] It should be noted that the above embodiments illustrate rather than limit the invention, and that alternative embodiments may be devised by a person skilled in the art without departing from the scope of the appended claims. In the claims, any reference signs placed between brackets should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising several different elements and by means of appropriately programmed computers. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments should not be understood as limiting the order of execution unless otherwise specified.

Claims

1. A method for controlling lubricating oil temperature of a steam turbine generator set, characterized in that: include: Obtaining a current temperature value of lubricating oil at a preset position of a target steam turbine generator set; generating a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at a circulating water inlet of an oil cooler of the target steam turbine generator set, and is configured to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set; Sending the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set; The step of generating a valve control signal for the electric valve of the target steam turbine generator set based on the fuzzy control algorithm and the current temperature value comprises: Obtaining a current temperature deviation value according to the current temperature value and the preset temperature value; generating the valve opening value based on the fuzzy control algorithm and the current temperature deviation value, and converting the target valve opening value into the valve control signal; The electric valve is provided with an electronic actuator, and the step of sending the valve control signal to the electric valve so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal to achieve control of the circulating water flow rate of the target steam turbine generator set includes: The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

2. The method for controlling lubricating oil temperature of a steam turbine generator set according to claim 1, characterized in that: The preset position is the oil outlet of the oil cooler, and the step of obtaining the current temperature value of the lubricating oil at the preset position of the target steam turbine generator set includes: The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is acquired.

3. The lubricating oil temperature control method for a steam turbine generator set according to claim 1 or 2, characterized in that: The target steam turbine generator set is a 15MW steam turbine generator set.

4. A lubricating oil temperature control system for a steam turbine generator set, characterized in that: include: Acquisition module, processing module and control module; The acquisition module is used to: obtain the current temperature value of the lubricating oil at a preset position of the target steam turbine generator set; The processing module is configured to generate a valve control signal for the electric valve of the target steam turbine generator set based on a fuzzy control algorithm and the current temperature value; wherein the electric valve is disposed at a circulating water inlet of an oil cooler of the target steam turbine generator set, and is configured to control the lubricating oil temperature of the steam turbine generator set by controlling the circulating water flow rate of the target steam turbine generator set; The control module is used to: send the valve control signal to the electric valve, so that the electric valve adjusts the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby controlling the circulating water flow of the target steam turbine generator set; The processing module is specifically used for: Obtaining a current temperature deviation value according to the current temperature value and the preset temperature value; generating the valve opening value based on the fuzzy control algorithm and the current temperature deviation value, and converting the target valve opening value into the valve control signal; The control module is specifically used for: The valve control signal is sent to the electronic actuator on the electric valve, so that the electronic actuator drives the valve core of the electric valve according to the valve control signal to adjust the opening value of the electric valve to the target valve opening value corresponding to the valve control signal, thereby realizing the control of the circulating water flow of the target steam turbine generator set.

5. The lubricating oil temperature control system of the steam turbine generator set according to claim 4, characterized in that: The preset position is: the oil outlet of the oil cooler, and the acquisition module is specifically used for: The current temperature value of the lubricating oil at the oil outlet of the oil cooler collected by the temperature sensor is obtained.

6. The lubricating oil temperature control system of a steam turbine generator set according to claim 4 or 5, characterized in that: The target steam turbine generator set is a 15MW steam turbine generator set.

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