A main steam flow measuring and calculating device and a measuring and calculating method

Abstract

This invention discloses a main steam flow rate calculation device and method, belonging to the field of main steam flow rate calculation technology. It includes a sampling header, a regulating stage pressure calculation component, an extraction steam pipeline, and a primary extraction pressure calculation component. The regulating stage pressure calculation component is located outside the sampling header, which is connected to the regulating stage of the steam turbine. An extraction steam pipeline is connected to the steam turbine, and a primary extraction pressure calculation component is installed on the extraction steam pipeline. The beneficial effects of this invention are: the regulating stage pressure calculation module can detect the pressure of the regulating stage connected to the steam turbine and calculate the main steam flow rate of the steam turbine, facilitating stable operation control by staff. Simultaneously, the switchable primary extraction pressure calculation module allows for temporary switching to the primary extraction pressure calculation module to calculate the main steam flow rate of the steam turbine in case of breakage or malfunction of the sampling header used for calculating the main steam flow rate of the regulating stage, thus ensuring the accuracy of the main steam flow rate value.

Description

Technical Field

[0001] This invention relates to the field of main steam flow measurement technology, and more specifically, to a main steam flow measurement device and measurement method. Background Technology

[0002] A thermal power plant, or coal-fired power plant for short, is a factory that uses combustible materials (such as coal) as fuel to produce electricity. Its basic production process is as follows: when fuel is burned, it heats water to generate steam, converting the chemical energy of the fuel into heat energy. The steam pressure drives the turbine to rotate, converting the heat energy into mechanical energy. Then, the turbine drives the generator to rotate, converting the mechanical energy into electrical energy.

[0003] The main steam flow rate of a thermal power generating unit refers to the mass flow rate of high-temperature, high-pressure main steam entering the high-pressure cylinder of the turbine per unit time. The unit is typically t / h or kg / s, and it is a fundamental parameter for monitoring the thermal performance and economic analysis of thermal power units. It is directly related to core indicators such as unit output, heat rate, and steam consumption rate.

[0004] Currently, the main steam flow rate of the steam turbine can be calculated from the steam pressure after the regulating stage. However, the three measuring points of the steam pressure after the regulating stage are installed on the same sampling header. Once the sampling header breaks or malfunctions, it will cause the steam pressure after the three regulating stages to fail, resulting in a sudden change in the main steam flow rate, which seriously affects the safe operation of the unit. In order to ensure that the main steam flow rate is not affected by the steam pressure measuring points of the regulating stage after the sampling header fails, an additional switchable main steam flow rate calculation method needs to be added to ensure the accuracy of the main steam flow rate measurement and maintain the safe and stable operation of the unit. Summary of the Invention

[0005] To overcome the problems in existing technologies where, to ensure the main steam flow rate is unaffected by the regulating stage steam pressure measurement point after a sampling header failure, an additional switchable main steam flow rate calculation method is needed to guarantee accurate main steam flow rate measurement and maintain the safe and stable operation of the unit, this invention provides a main steam flow rate calculation device, including a sampling header, a regulating stage pressure calculation component, an extraction steam pipeline, and a first extraction pressure calculation component. The regulating stage pressure calculation component is located outside the sampling header, the sampling header is connected to the regulating stage of the steam turbine, the steam turbine is connected to an extraction steam pipeline, and a first extraction pressure calculation component is installed on the extraction steam pipeline. A control box is connected between the regulating stage pressure calculation component and the first extraction pressure calculation component, and a control host is installed inside the control box.

[0006] The regulating pressure measurement component includes a pressure sensing tube and a pressure transmitter. The pressure transmitter is connected to the pressure sensing tube, which is connected to the outer wall of the sampling main tube.

[0007] The extraction pressure measurement component includes a detection connection pipe and a pressure sensor. The pressure sensor is connected to the detection connection pipe, which is connected to the side wall of the extraction pipe.

[0008] The input terminal of the control host is connected to the pressure transmitter and pressure sensor via wires. The control host is equipped with a regulating stage pressure calculation module and a primary pumping pressure calculation module, and a switching module is connected between the regulating stage pressure calculation module and the primary pumping pressure calculation module.

[0009] The system includes a regulating stage pressure calculation module, which can detect the pressure of the regulating stage connected to the turbine through multiple pressure measuring points on the sampling header and calculate the main steam flow of the turbine. This facilitates the stable operation of the turbine under the control of the staff. Additionally, a switchable extraction pressure calculation module is included. In the event of a break or malfunction in the sampling header used for calculating the main steam flow of the regulating stage, the system can be temporarily switched to the extraction pressure calculation module to calculate the main steam flow of the turbine. This ensures the accuracy of the main steam flow value and facilitates the optimization of the overall thermal power unit load and ensures the safe operation of the unit.

[0010] Preferably, the pressure transmitter is electrically connected to the regulating stage pressure calculation module via the control host, the pressure sensor is electrically connected to the first-stage pressure calculation module via the control host, and the input terminal of the control host is connected to the switching module.

[0011] Preferably, an alarm is installed on the control box, and the alarm is electrically connected to the pressure transmitter and pressure sensor through the control host. The alarm can be used during the calculation of the main steam flow rate of the steam turbine. When the main steam flow rate of the steam turbine exceeds the preset normal range, the alarm can be triggered to remind staff to handle the situation promptly and perform maintenance on the thermal power unit.

[0012] Preferably, a display is mounted on the front of the control box, and the display is electrically connected to the pressure transmitter and pressure sensor through the control host.

[0013] Preferably, the sampling header is provided with three pressure measuring points, each of which is connected to three pressure detection tubes, and the three pressure detection tubes are respectively connected to three pressure transmitters.

[0014] Preferably, the outer wall of the control box is provided with a number of heat dissipation holes.

[0015] Preferably, the control box is equipped with a protective plate on its exterior.

[0016] A control box is installed next to the thermal power generation unit, and the regulating stage pressure calculation module, the first extraction pressure calculation module and the switching module are integrated inside the control box. This facilitates the rapid and efficient calculation of the main steam flow of the steam turbine, and makes it easy for staff to view and manage the operation in real time.

[0017] This invention also discloses a calculation method using a main steam flow measurement device, comprising the following steps:

[0018] Step 1: The pressure measurement component of the regulating stage measures the pressure of the sampling header connected to the regulating stage of the steam turbine and transmits the pressure signal to the control host.

[0019] Step two: The control host analyzes the pressure data and calculates the main steam flow rate of the turbine through the regulating stage pressure calculation module;

[0020] Step 3: When the turbine main steam flow data calculated by the regulating stage pressure calculation module is abnormal, the regulating stage pressure measuring point is determined to be faulty.

[0021] Step 4: Activate the switching module and switch the main steam flow calculation method to the primary extraction pressure calculation module;

[0022] Step 5: The first extraction pressure of the turbine extraction pipeline is detected by the first extraction pressure measurement component, and the pressure data is transmitted to the control host.

[0023] Step six: The control host analyzes the pressure data and temporarily calculates the main steam flow rate of the turbine through the first extraction pressure calculation module;

[0024] Step 7: Obtain a relatively accurate turbine main steam flow rate.

[0025] Preferably, in step one, three pressure measuring points are set on the sampling header, and the highest and lowest values ​​are removed during the calculation.

[0026] Preferably, in step four, the switching module is a manual switching switch or an automatic switching switch.

[0027] Two sets of calculation formulas are set up to calculate the main steam flow of the turbine. When the commonly used regulating stage steam flow measurement point fails, the calculation can be switched to the backup calculation formula, namely the first extraction pressure calculation formula, to ensure the accuracy of the main steam flow value.

[0028] Beneficial effects:

[0029] The beneficial effects of adopting the technical solution of this invention are as follows:

[0030] (1) A regulating stage pressure calculation module is set up so that the pressure of the regulating stage connected to the steam turbine can be detected through multiple pressure measuring points on the sampling header and the main steam flow of the steam turbine can be calculated. This makes it easier for staff to control the stable operation of the steam turbine. At the same time, a switchable first-stage pressure calculation module is set up so that when the sampling header used for regulating stage pressure calculation of main steam flow is broken or malfunctions, the first-stage pressure calculation module can be temporarily switched to calculate the main steam flow of the steam turbine, thereby ensuring the accuracy of the main steam flow value and providing convenience for the optimization of the load of the entire thermal power unit and ensuring the safe operation of the unit.

[0031] (2) An alarm device is set up and can be used in the process of measuring the main steam flow of the steam turbine. When the main steam flow of the steam turbine exceeds the preset normal range, an alarm can be issued through the alarm device to remind the staff to deal with it in time and carry out maintenance of the thermal power unit.

[0032] (3) A control box is set up next to the thermal power generation unit, and the regulating stage pressure calculation module, the first extraction pressure calculation module and the switching module are integrated inside the control box. This makes it easy to quickly and efficiently calculate the main steam flow of the steam turbine, and facilitates real-time viewing and management control by the staff.

[0033] (4) Two sets of calculation formulas are set to calculate the main steam flow of the turbine. When the commonly used regulating stage steam flow measurement point fails, the calculation formula can be switched to the backup formula, namely the first extraction pressure calculation formula, to ensure the accuracy of the main steam flow value. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the overall structure of the main steam flow detection device of the present invention;

[0036] Figure 2 This is a schematic diagram of the internal connection structure of the control box on the main steam flow detection device of the present invention;

[0037] Figure 3 This is a schematic diagram of the internal structure of the steam extraction pipe on the main steam flow detection device of the present invention;

[0038] Figure 4 This is a flowchart of the main steam flow detection device and calculation method of the present invention;

[0039] Figure 5This is a logic block diagram of the main steam flow detection device and calculation method of the present invention.

[0040] In the diagram: 1. Steam turbine; 2. Regulating stage; 3. Sampling header; 4. Pressure transmitter; 5. Control box; 6. Alarm; 7. Display; 8. Extraction steam pipeline; 9. Pressure sensor; 10. Control host; 11. Regulating stage pressure calculation module; 12. First extraction pressure calculation module; 13. Switching module; 14. Protective plate; 15. Insulation protection plate. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] This implementation method, by setting up a regulating stage pressure calculation module, can detect the pressure of the regulating stage connected to the steam turbine through multiple pressure measuring points on the sampling header and calculate the main steam flow of the steam turbine. This facilitates the stable operation of the steam turbine under the control of the staff. Simultaneously, a switchable first-stage pressure calculation module is provided. In the event of a break or malfunction in the sampling header used for calculating the main steam flow of the regulating stage, the system can temporarily switch to the first-stage pressure calculation module to calculate the main steam flow of the steam turbine, thereby ensuring the accuracy of the main steam flow value. This provides convenience for optimizing the load of the entire thermal power unit and ensuring the safe operation of the unit. The specific implementation method is as follows:

[0043] like Figures 1 to 5As shown, a main steam flow measurement device includes a sampling header 3, a regulating stage pressure measurement component, an extraction steam pipe 8, and a first extraction pressure measurement component. The regulating stage pressure measurement component is located outside the sampling header 3, which is connected to the regulating stage 2 of the steam turbine 1. The steam turbine 1 is connected to the extraction steam pipe 8, and the first extraction pressure measurement component is installed on the extraction steam pipe 8. A control box 5 connects the regulating stage pressure measurement component and the first extraction pressure measurement component, and a control host 10 is installed inside the control box 5. The regulating stage pressure measurement component includes a pressure detection tube and a pressure transmitter 4. Transmitter 4 is connected to a pressure detection tube, which is connected to the outer wall of the sampling header 3; the primary extraction pressure calculation component includes a detection connection pipe and a pressure sensor 9, which is connected to the detection connection pipe, which is connected to the side wall of the extraction steam pipe 8; the input terminal of the control host 10 is connected to the pressure transmitter 4 and the pressure sensor 9 via wires, and the control host 10 is equipped with a regulating stage pressure calculation module 11 and a primary extraction pressure calculation module 12, respectively, and a switching module 13 is connected between the regulating stage pressure calculation module 11 and the primary extraction pressure calculation module 12.

[0044] Main steam flow rate: This refers to the mass flow rate of high-temperature, high-pressure steam generated by the boiler in a thermal power plant, which enters the steam turbine through the main steam pipeline. This parameter is the core basis for calculating turbine load, power, and efficiency, and is also a key monitoring indicator for the safe and stable operation of the unit.

[0045] Regulation stage: This refers to the first pressure stage of the steam turbine, also known as the impulse stage. The main steam first enters the regulation stage to do work. The pressure after the regulation stage has an approximately linear relationship with the main steam flow rate, so it is often used as the main parameter for calculating the main steam flow rate and has high measurement accuracy.

[0046] First-stage extraction pressure: This refers to the steam pressure at the first-stage extraction port of the steam turbine. This pressure is also related to the main steam flow rate. Although its accuracy in calculating the main steam flow rate is slightly lower than that of the regulating stage pressure, it can serve as a reliable alternative calculation basis when the regulating stage pressure measurement fails.

[0047] The regulating stage pressure calculation module 11 is set up to detect the pressure of the regulating stage connected to the steam turbine 1 through multiple pressure measuring points on the sampling header 3, and to calculate the main steam flow of the steam turbine 1. This facilitates the staff to control the stable operation of the steam turbine 1. At the same time, a switchable first-extraction pressure calculation module 12 is set up. When the sampling header 3 used for calculating the main steam flow of the regulating stage is broken or malfunctions, the first-extraction pressure calculation module 12 can be temporarily switched to calculate the main steam flow of the steam turbine 1, thereby ensuring the accuracy of the main steam flow value. This provides convenience for optimizing the load of the entire thermal power unit and ensuring the safe operation of the unit.

[0048] Specifically, the main function of sampling header 3 is to sample the steam pressure after the regulating stage. It is generally installed on or near the inner wall after the cylinder regulating stage, directly connected to the high-pressure steam zone. The sampling point is selected in a location with stable and undisturbed steam flow to ensure accurate measurement. Sampling header 3 is connected to pressure transmitter 4. High-pressure steam enters pressure transmitter 4 through the sampling header. The transmitter converts the pressure signal into a standard electrical signal, which is then sent to the control system for display and regulation.

[0049] Specifically, the regulating stage pressure calculation module 11 internally stores mathematical models or empirical formulas for calculating main steam flow based on regulating stage pressure. Its core is the Flügger formula, which indirectly calculates main steam flow using the pressure after the regulating stage and the main steam temperature. This is particularly suitable for large steam turbines, avoiding the inconvenience and errors of direct measurement. Based on the turbine's thermodynamic process, it assumes that the flow rate is proportional to the pressure after the regulating stage, and calculates the flow rate using measured pressure and temperature combined with design parameters. Simplified formula: ,

[0050] Parameter description:

[0051] m: Main steam flow rate (t / h or kg / s);

[0052] : Regulating stage pressure (MPa);

[0053] T: Regulating stage temperature (K);

[0054] k: Proportional coefficient (related to unit structure and steam properties), calibrated by unit thermodynamic characteristic test.

[0055] In normal operating mode, the module receives signals from the pressure transmitter and calculates the main steam flow rate in real time.

[0056] Specifically, the primary extraction pressure calculation module 12 stores backup mathematical models or empirical formulas for calculating main steam flow rate based on the primary extraction pressure. Its core is a variant of the Vlugel formula, where the relationship between main steam flow rate and extraction port pressure can be expressed as: G = ,

[0057] Parameter description:

[0058] G: Main steam flow rate (kg / s);

[0059] Absolute pressure at the first-stage extraction port (MPa);

[0060] Exhaust pressure (MPa);

[0061] T: Steam temperature at the extraction port (K);

[0062] k: A constant related to the turbine flow area and steam properties.

[0063] This module receives signals from the pressure sensor and performs backup calculations. When the primary path is normal, the calculation results of this module can be used as a reference or not enabled.

[0064] In a preferred embodiment, the pressure transmitter 4 is electrically connected to the regulating stage pressure calculation module 11 via the control host 10, and the pressure sensor 9 is electrically connected to the first-stage pressure calculation module 12 via the control host 10. The input terminal of the control host 10 is connected to the switching module 13. The control host 10 is an embedded industrial controller with an internal DCS control system. Its hardware input terminal is connected to the output terminals of the pressure transmitter and pressure sensor via wires to receive two independent pressure signals. The software logic of the control host includes two core functional modules: the regulating stage pressure calculation module and the first-stage pressure calculation module. The pressure transmitter 4 is a key device in industrial automation that measures pressure and converts it into a standard electrical signal. It is commonly used in scenarios such as steam turbine steam flow measurement to ensure the safe and stable operation of the system by monitoring pressure parameters. It converts pressure changes into standard signals such as 4-20mA or 0-10V through pressure-sensitive elements (such as capacitive or strain gauge types), facilitating remote transmission and control system processing. In steam turbine steam flow measurement, it is often combined with the Flueger formula to indirectly calculate the main steam flow by measuring parameters such as the regulating stage pressure. The pressure sensor 9 can have the same structure as the pressure transmitter 4, or it can be a dedicated steam pressure sensing element.

[0065] Specifically, the function of the switching module 13 is to determine, based on preset conditions or external instructions, whether the final output main steam flow value comes from the module or from the module regulating stage pressure calculation module 11 and the first extraction pressure calculation module 12.

[0066] In a preferred embodiment, an alarm 6 is installed on the control box 5. The alarm 6 is electrically connected to the pressure transmitter 4 and the pressure sensor 9 via the control host 10. The alarm 6 is an audible and visual alarm element, which can be used in the calculation of the main steam flow of the steam turbine 1. When the main steam flow of the steam turbine 1 exceeds the preset normal range, the alarm 6 can sound an alarm to remind the staff to deal with the situation in time, carry out maintenance and repair of the thermal power unit, and avoid accidents.

[0067] In a preferred embodiment, a display 7 is mounted on the front of the control box 5. The display 7 is electrically connected to the pressure transmitter 4 and the pressure sensor 9 via the control host 10. The display 7 can display the pressure data of the pressure transmitter 4 and the pressure sensor 9. The display 7 is connected to the output terminal of the control host 10 and can also display the calculation data of the regulating stage pressure calculation module 11 and the first-stage pressure calculation module 12.

[0068] Example 1

[0069] Three pressure measuring points are set on the sampling header 3, and each pressure measuring point is connected to three pressure detection tubes, which are in turn connected to three pressure transmitters 4. By setting up multiple pressure measuring points, the accuracy of the main steam flow data can be improved during calculation, and the intermediate value will be used for calculation.

[0070] In a preferred embodiment, the outer wall of the control box 5 is provided with several heat dissipation holes. The heat dissipation holes can improve the heat dissipation capacity of the control box 5, prevent the internal components from overheating, and at the same time, a cooling fan can be installed on the control box 5 to blow air and dissipate heat, thereby improving the service life of internal components such as the control host 10.

[0071] In a preferred embodiment, a protective plate 14 is installed on the outside of the control box 5. The protective plate 14 can improve the external safety protection of the control box 5 and enhance its resistance to pressure and impact. At the same time, an insulating protective plate 15 is provided on the inner wall of the control box 5, which can improve the insulation protection capability of the control box and avoid leakage and electrostatic interference.

[0072] Example 2

[0073] In this embodiment, the switching module 13 is a manual switching switch. After the alarm 6 sounds, the staff can know that the calculation of the main steam flow of the turbine 1 calculated by the regulating stage pressure calculation module 11 is abnormal and the pressure measuring point is faulty. They can directly operate the manual switching switch to switch to the first extraction pressure calculation module 12 for temporary main steam flow calculation, thereby ensuring the accuracy of the calculation results and avoiding excessive errors.

[0074] Example 3

[0075] In this embodiment, the switching module 13 is an automatic switching switch. After the control host 10 detects that the main steam flow of the turbine 1 calculated by the regulating stage pressure calculation module 11 exceeds the normal reset, it can determine that the pressure measuring point is faulty and directly control the automatic switching switch to switch to the first extraction pressure calculation module 12 for temporary main steam flow calculation, thereby ensuring the accuracy of the calculation results and avoiding excessive errors.

[0076] A control box 5 is installed next to the thermal power generation unit, and the regulating stage pressure calculation module 11, the first extraction pressure calculation module 12 and the switching module 13 are integrated inside the control box 5. This facilitates the rapid and efficient calculation of the main steam flow of the steam turbine 1, and makes it easy for staff to view and manage the system in real time.

[0077] This invention also discloses a calculation method using a main steam flow measurement device, comprising the following steps:

[0078] Step S101: The pressure measurement component of the regulating stage performs pressure detection on the sampling header connected to the regulating stage of the steam turbine and transmits the pressure signal to the control host.

[0079] In step S102, the control host analyzes the pressure data and calculates the main steam flow rate of the turbine through the regulating stage pressure calculation module;

[0080] Step S103: When the turbine main steam flow data calculated by the regulating stage pressure calculation module is abnormal, the regulating stage pressure measuring point is determined to be faulty.

[0081] Step S104: Start the switching module and switch the main steam flow calculation method to the primary extraction pressure calculation module;

[0082] Step S105: The first extraction pressure of the turbine extraction pipeline is detected by the first extraction pressure measurement component, and the pressure data is transmitted to the control host.

[0083] In step S106, the control host analyzes the pressure data and temporarily calculates the main steam flow rate of the steam turbine through the first extraction pressure calculation module;

[0084] Step S107 yields a relatively accurate turbine main steam flow rate.

[0085] As a preferred implementation, in step one, three pressure measuring points are set on the sampling header, and the highest and lowest values ​​are removed during the calculation.

[0086] In a preferred embodiment, in step four, the switching module is a manual switching switch or an automatic switching switch.

[0087] Two sets of calculation formulas are set up to calculate the main steam flow rate of the steam turbine. When the commonly used regulating stage steam flow measurement point fails, the calculation can be switched to the backup formula, namely the extraction pressure calculation formula, to ensure the accuracy of the main steam flow rate value. Figure 5 In the logic block diagram shown, a pressure calculation and regulation stage pressure formula is added to the DCS system control station logic, and a pressure conversion button measurement point and screen are added.

[0088] Furthermore, refer to Figure 5 The control logic structure diagram shown provides a better understanding of the internal workflow of the control host. The regulating stage pressure calculation component corresponds to the main regulating stage pressure measurement unit in the diagram, and the pressure data it collects is sent to the control host. The first-stage pressure calculation component corresponds to the first-stage steam pressure measurement unit in the diagram, and the pressure data it collects is sent to the backup pressure calculation module, which is the aforementioned first-stage pressure calculation module.

[0089] The output of the primary regulating stage pressure measurement unit is sent to both the selection module and the fault detection module. The fault detection module determines whether a fault has occurred in the primary measurement path. The selection module, implemented by the aforementioned switching module, receives measurement data from the primary regulating stage pressure measurement unit, calculation results from the standby pressure calculation module, judgment signals from the fault detection module, and instructions from any external switching signal input units. Based on these inputs, the selection module decides which calculation result to ultimately provide to the output module. The output module is responsible for sending the final determined main steam flow value to the power plant's DCS system or displaying it locally.

[0090] Through the above structure, this device constructs a primary and backup redundant measurement and calculation system. When the primary regulating stage pressure measurement path is working normally, the system uses high-precision regulating stage pressure for calculation; once the primary path fails (e.g., sampling header failure), the system can quickly switch to the backup primary extraction pressure calculation path, thereby avoiding the loss or sudden zeroing of the main steam flow signal and ensuring the safe and stable operation of the steam turbine and the entire generator unit.

[0091] The main application scenarios for this invention are large and medium-sized thermal power plants, combined heat and power units, and other applications using industrial steam turbines. In these scenarios, the main steam flow rate is a core parameter for controlling the steam inlet to the turbine, regulating the unit load, and protecting equipment safety. Applying the device and method of this invention to the distributed control system (DCS) of a power plant can serve as a highly reliable data acquisition and preprocessing module.

[0092] Working Principle: A regulating stage pressure calculation module is installed, which can detect the pressure of the regulating stage connected to the steam turbine through multiple pressure measuring points on the sampling header and calculate the main steam flow of the steam turbine. This facilitates stable operation control of the steam turbine. Simultaneously, a switchable extraction pressure calculation module is provided. In case of a break or malfunction in the sampling header used for calculating the main steam flow of the regulating stage, the module can be temporarily switched to calculate the main steam flow of the steam turbine, ensuring accurate main steam flow values. This facilitates the optimization of the overall thermal power unit load and ensures safe operation of the unit. An alarm is installed during the main steam flow calculation process. When the main steam flow of the steam turbine exceeds the preset normal range, the alarm will sound, reminding staff to handle the situation promptly. For maintenance and repair of thermal power units, a control box is installed next to the unit, integrating the regulating stage pressure calculation module, the extraction pressure calculation module, and the switching module. This allows for rapid and efficient calculation of the main steam flow of the steam turbine, facilitating real-time monitoring and management by staff.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A device for measuring and calculating the flow of main steam, characterized in that Including sampling main pipe (3), adjusting stage pressure measurement assembly, steam extraction pipeline (8) and a steam extraction pressure measurement assembly, the adjusting stage pressure measurement assembly is arranged outside the sampling main pipe (3), the sampling main pipe (3) is connected on the adjusting stage (2) of steam turbine (1), the steam turbine (1) is connected with steam extraction pipeline (8), a steam extraction pressure measurement assembly is installed on the steam extraction pipeline (8), the adjusting stage pressure measurement assembly and a steam extraction pressure measurement assembly are connected with control box (5), control host (10) is installed in control box (5); The adjusting stage pressure measurement assembly includes a pressure detection tube and a pressure transmitter (4), the pressure transmitter (4) is connected with the pressure detection tube, and the pressure detection tube is connected to the outer wall of the sampling main pipe (3); The steam extraction pressure measurement assembly includes a detection connection pipeline and a pressure sensor (9), the pressure sensor (9) is connected with the detection connection pipeline, and the detection connection pipeline is connected to the side wall of the steam extraction pipeline (8); The input end of the control host (10) is connected with the pressure transmitter (4) and the pressure sensor (9) through wires, the control host (10) is respectively provided with an adjusting stage pressure calculation module (11) and a steam extraction pressure calculation module (12), and the adjusting stage pressure calculation module (11) and the steam extraction pressure calculation module (12) are connected with a switching module (13).

2. A device for measuring and calculating the flow of steam according to claim 1, characterized in that The pressure transmitter (4) is electrically connected with the adjusting stage pressure calculation module (11) through the control host (10), the pressure sensor (9) is electrically connected with the steam extraction pressure calculation module (12) through the control host (10), and the input end of the control host (10) is connected with the switching module (13).

3. The device of claim 1, wherein: The control box (5) is provided with an alarm (6), and the alarm (6) is electrically connected with the pressure transmitter (4) and the pressure sensor (9) through the control host (10).

4. The device of claim 1, wherein The front of the control box (5) is provided with a display (7), and the display (7) is electrically connected with the pressure transmitter (4) and the pressure sensor (9) through the control host (10).

5. The device of claim 1, wherein: The sampling main pipe (3) is provided with three pressure measuring points, each of which is connected with three pressure detection tubes, and the three pressure detection tubes are respectively connected with three pressure transmitters (4).

6. The device of claim 1, wherein: The outer wall of the control box (5) is provided with a plurality of heat dissipation holes.

7. The device of claim 1, wherein: The control box (5) is externally provided with a protective plate (14).

8. A measuring method using the main steam flow measuring device according to any one of claims 1 to 7, characterized by, The method comprises the following steps: Step one, the pressure of the sampling main pipe connected with the adjusting stage of the steam turbine is detected by the adjusting stage pressure measurement assembly, and the pressure signal is transmitted to the control host; Step two, the control host analyzes the pressure data and calculates the steam turbine main steam flow through the adjusting stage pressure calculation module; Step three, when the steam turbine main steam flow data calculated through the adjusting stage pressure calculation module is abnormal, it is determined that the adjusting stage pressure measuring point is faulty; Step four, the switching module is started, and the main steam flow calculation mode is switched to the steam extraction pressure calculation module; Step five, the steam extraction pressure of the steam extraction pipeline of the steam turbine is detected by the steam extraction pressure measurement assembly, and the pressure data is transmitted to the control host; Step six: The control host analyzes the pressure data and temporarily calculates the main steam flow rate of the turbine through the first extraction pressure calculation module; Step 7: Obtain a relatively accurate turbine main steam flow rate.

9. The method of claim 8, wherein, In step one, three pressure measuring points are set on the sampling header, and the highest and lowest values ​​are removed during the calculation.

10. The method of claim 8, wherein, In step four, the switching module is either a manual switching switch or an automatic switching switch.

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