Cutter state monitoring system and monitoring method for steam turbine blade machining

Abstract

The invention provides a tool state monitoring system and method for steam turbine blade machining, and aims to overcome the defects that in the prior art, the tool state is prone to being misjudged, and therefore the machining quality and machining efficiency of steam turbine blades are reduced. The invention relates to the technical field of cutter state monitoring, and discloses a steam turbine blade machining cutter state monitoring system which is provided with a temperature sensor, a rotating speed sensor, an industrial personal computer, a memory, a display, an alarm and a communication module, and the rotating speed sensor detects the rotating speed of a steam turbine blade machining cutter in real time and transmits a detected rotating speed signal to a central processing unit; and the central processing unit calculates the received data and further outputs a signal of the state of the cutter. According to the method, the accuracy and reliability of state monitoring of the cutter for turbine blade machining are remarkably improved, misjudgment of the cutter state is avoided, and the machining quality and machining efficiency of the turbine blade are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tool status monitoring, and in particular to a tool status monitoring system and a monitoring method for processing steam turbine blades. Background Art

[0002] Steam turbine blades include moving blades and stationary blades. They are key components of steam turbines and one of the most delicate and important components. They withstand high temperature, high pressure, huge centrifugal force, steam force, steam excitation force, corrosion and vibration, as well as water droplet erosion in the wet steam zone under extremely harsh conditions. Factors such as their aerodynamic performance and surface roughness affect the efficiency of the steam turbine.

[0003] Steam turbine blade machining tools are tools specially used for machining steam turbine blades. Due to the importance of steam turbine blades to steam turbines, the condition monitoring of steam turbine blade machining tools has become an important means to ensure the machining quality of steam turbine blades. The blade wear and service life of steam turbine blade machining tools are directly related to their machining quality.

[0004] Traditional tool status monitoring for turbine blade machining mainly relies on manual inspection and experience-based judgment, which can easily lead to misjudgment of tool status and reduce turbine blade machining quality and efficiency. Summary of the Invention

[0005] The purpose of the present invention is to solve the defect of the prior art that the tool status is easily misjudged, thereby reducing the processing quality and efficiency of turbine blades, and to provide a tool status monitoring system and monitoring method for turbine blade processing.

[0006] To achieve the purpose of the present invention, the technical solution adopted is: A tool status monitoring system for processing steam turbine blades, comprising a temperature sensor, a speed sensor, an industrial computer, a memory, a display, an alarm, and a communication module; Among them, a central processing unit is provided in the industrial computer; the signal output end of the speed sensor is connected to the speed signal input end of the central processing unit in the industrial computer; the memory is connected to the storage end of the central processing unit; the signal input end of the display is connected to the display signal output end of the central processing unit; the signal input end of the alarm is connected to the alarm signal output end of the central processing unit; and the local communication end of the communication module is connected to the communication end of the central processing unit.

[0007] Preferably, the rotation speed sensor is mounted on or beside the tool for machining the steam turbine blades.

[0008] Preferably, the memory is connected to the storage end of the central processing unit in a bidirectional manner.

[0009] Preferably, the local communication terminal of the communication module and the communication terminal of the central processing unit are connected in a bidirectional manner.

[0010] Preferably, the signal output terminal of the temperature sensor is connected to the temperature signal input terminal of the central processing unit.

[0011] A monitoring method for implementing the above-mentioned tool status monitoring system for steam turbine blade machining comprises the following steps: (1) Start the equipment to start the turbine blade processing tool to work, detect the speed of the turbine blade processing tool in real time through the speed sensor, and transmit the detected speed signal to the central processing unit; (2) After receiving the speed signal, the CPU calculates the blade wear of the tool used for machining the turbine blade using the following formula: Wherein, W is the blade wear, in mm; K is the cutting fragility coefficient of the tool for machining steam turbine blades, which is a known number, preferably 0.001-0.004; C is the cutting hardness coefficient of the tool for machining steam turbine blades, which is a known number, preferably 0.25-0.40; V is the linear speed of the tool for machining steam turbine blades, in m / min, preferably 180-300 m / min; t is the total working time of the tool for machining steam turbine blades, in min; a is an empirical coefficient, obtained based on experience with tool materials, preferably 8000-12000; (3) The central processing unit compares the blade wear amount calculated in step (2) with the set wear amount threshold. When the blade wear amount is less than the wear amount threshold, the process goes to step (4). When the blade wear amount reaches the set wear amount threshold, the central processing unit sends an alarm signal to the alarm device and displays the alarm information on the display to remind the staff to replace the tool, thus ending the tool monitoring. (4) The CPU calculates the cutting force of the blade used for machining turbine blades according to the following formula: Among them, F is the cutting force of the blade, the unit is N; V B is the wear correction coefficient, preferably 0.1-0.5. As VB increases, the blade back wear increases and the cutting force becomes larger; a p is the cutting depth of the tool, in mm, preferably 0.5-5 mm; f The feed rate of the tool used for machining turbine blades is in mm / r, preferably 0.05-0.3 mm / r; is the unit cutting force, unit N / mm 2 , preferably 1800-4000N / mm 2 ; (5) The CPU calculates the service life of the tool used for machining turbine blades according to the following formula: in, S is the service life of the tool used for machining turbine blades, in min; B is the empirical constant of the tool-workpiece system, preferably 150-300; The linear speed of the tool used for machining turbine blades is in m / min, preferably 180-300 m / min; n is the influence index of cutting speed on tool life, preferably 0.1-0.5; f is the feed rate of the tool used for machining turbine blades, in mm / r, preferably 0.05-0.3 mm / r; m is the index of the influence of feed rate on tool life, preferably 0.5-0.8; a p is the cutting depth of the tool, in mm, preferably 0.5-5 mm; p is the influence index of cutting depth on tool life, preferably 0.1-0.3; is the unit cutting force, unit N / mm 2 , preferably 1800-4000N / mm 2 ; F is the cutting force of the blade, the unit is N; (6) The central processing unit compares the service life of the steam turbine blade processing tool calculated in step (5) with the actual working time of the steam turbine blade processing tool. When the actual working time of the steam turbine blade processing tool reaches the service life of the steam turbine blade processing tool, the central processing unit sends an alarm signal to the alarm device and displays the alarm information on the display to remind the staff to replace the tool, thereby ending the tool monitoring.

[0012] The above technical solution has the following beneficial effects: The present invention monitors the blade wear and tool life of the turbine blade processing tool respectively. When the blade wear reaches a set wear threshold, or the actual working time of the turbine blade processing tool reaches the service life of the turbine blade processing tool, an alarm signal is promptly issued to remind the staff that the tool needs to be replaced, so as to prevent the turbine blade processing tool from continuing to work due to excessive wear or reaching the service life, resulting in reduced processing quality or safety accidents. The present invention significantly improves the accuracy and reliability of the status monitoring of the turbine blade processing tool, avoids misjudgment of the tool status, and improves the turbine blade processing quality and processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural block diagram of a tool status monitoring system for machining steam turbine blades according to the present invention; Figure 2The figure is a flow chart of the tool status monitoring method for machining turbine blades according to the present invention. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] Example 1 like Figure 1 As shown, the present invention provides a tool status monitoring system for turbine blade processing, which includes a temperature sensor, a speed sensor, an industrial computer, a memory, a display, an alarm, a temperature sensor and a communication module. A central processing unit is provided in the industrial computer. The speed sensor is installed on the tool for processing the turbine blade or next to the tool for processing the turbine blade. The signal output end of the speed sensor is connected to the speed signal input end of the central processing unit in the industrial computer, the memory is connected to the storage end of the central processing unit, the signal input end of the display is connected to the display signal output end of the central processing unit, the signal input end of the alarm is connected to the alarm signal output end of the central processing unit, the local communication end of the communication module is connected to the communication end of the central processing unit, and the signal output end of the temperature sensor is connected to the temperature signal input end of the central processing unit.

[0016] Example 2 like Figure 2 As shown, the present invention provides a method for monitoring the status of a tool for machining a turbine blade, which is implemented by the tool status monitoring system for machining a turbine blade, and includes the following steps: (1) The equipment is started to start the tool for processing the turbine blades. The speed sensor is used to detect the speed of the tool for processing the turbine blades in real time, and the detected speed signal is transmitted to the central processing unit.

[0017] (2) After receiving the speed signal, the CPU calculates the blade wear of the tool used for machining the turbine blade using the following formula: Background D=32mm semi-finishing milling ; W =0.432mm Among them, W is the blade wear, the unit is mm; K is the cutting fragility coefficient of the tool used for processing turbine blades, which is a known number; C is the cutting hardness coefficient of the tool used for processing turbine blades, which is a known number; V is the linear speed of the tool used for processing turbine blades, the unit is m / min; t is the total working time of the tool used for processing turbine blades, the unit is min; a is an empirical coefficient, which is obtained based on the experience of using tool materials and is taken as 10000.

[0018] (3) The CPU compares the blade wear amount 0.432 mm calculated in step (2) with the set wear amount threshold 0.6 mm (roughing). If the blade wear amount is less than the wear amount threshold, the CPU goes to step (4). (4) The CPU calculates the cutting force of the blade used for machining turbine blades according to the following formula: , , , ; ; in, is the cutting force of the blade, the unit is N; V B is the wear correction coefficient, the value range is between 0.1-0.5; a p is the cutting depth of the tool, in mm; f is the feed rate of the tool used for machining turbine blades, the unit is mm / r; is the unit cutting force, unit N / mm 2 .

[0019] (5) The CPU calculates the service life of the tool used for machining turbine blades according to the following formula: According to the above formula: B=200, n=0.5, m=0.5, , , , , , ; The calculation shows that S≈33min; in, S is the service life of the tool used for machining turbine blades, in min; B is the empirical constant of the tool-workpiece system, with a value range of 150-300; is the linear speed of the tool used for machining turbine blades, in m / min; nis the influence index of cutting speed on tool life, with a value range of 0.1-0.5; F is the cutting force of the blade, in N; f is the feed rate of the tool used for machining turbine blades, the unit is mm / r; m is the influence index of feed rate on tool life, and its value range is between 0.5-0.8; a p is the cutting depth of the tool, in mm; p is the influence index of cutting depth on tool life, with a value range of 0.1-0.3; is the unit cutting force, unit N / mm 2 ; (6) The central processing unit compares the service life S≈33min of the tool for processing the turbine blades with the actual working time of the tool for processing the turbine blades, which is about 40min. The actual working time of the tool for processing the turbine blades reaches the service life of the tool for processing the turbine blades. The central processing unit sends an alarm signal to the alarm device and displays the alarm information on the display to remind the staff to replace the tool, thereby ending the tool monitoring.

[0020] Example 3 A method for monitoring the status of a tool for machining a steam turbine blade provided by the present invention is implemented by the tool status monitoring system for machining a steam turbine blade described in Example 1, and includes the following steps: (1) Start the equipment to start the turbine blade processing tool to work, detect the speed of the turbine blade processing tool in real time through the speed sensor, and transmit the detected speed signal to the central processing unit; (2) After receiving the speed signal, the CPU calculates the blade wear of the tool used for machining the turbine blade using the following formula: , K= 0.002, C= 0.3 ，t= 42min, a = 10000; W =0.6048mm; (3) The CPU compares the blade wear calculated in step (2) W =0.6048mm and the set wear threshold of 0.6mm. It can be seen that the blade wear has reached the set wear threshold. The central processing unit sends an alarm signal to the alarm and displays the alarm information on the display to remind the staff to replace the tool and end the tool monitoring.

[0021] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A tool status monitoring system for steam turbine blade machining, characterized by: Including temperature sensor, speed sensor, industrial computer, memory, display, alarm and communication module; The industrial computer is provided with a central processing unit; The signal output end of the speed sensor is connected to the speed signal input end of the central processing unit in the industrial computer; the memory is connected to the storage end of the central processing unit; the signal input end of the display is connected to the display signal output end of the central processing unit; the signal input end of the alarm is connected to the alarm signal output end of the central processing unit; the local communication end of the communication module is connected to the communication end of the central processing unit.

2. The tool status monitoring system for steam turbine blade machining according to claim 1, characterized in that: The rotation speed sensor is mounted on the tool for machining the steam turbine blade or beside the tool for machining the steam turbine blade.

3. The tool status monitoring system for steam turbine blade machining according to claim 1, characterized in that: The memory is connected to the storage end of the central processing unit in a bidirectional manner.

4. The tool status monitoring system for steam turbine blade machining according to claim 1, characterized in that: The local communication terminal of the communication module is connected to the communication terminal of the central processing unit in a bidirectional manner.

5. The tool status monitoring system for steam turbine blade machining according to claim 1, characterized in that: The signal output end of the temperature sensor is connected to the temperature signal input end of the central processing unit.

6. A monitoring method for a tool status monitoring system for machining steam turbine blades according to any one of claims 1 to 5, characterized in that: Including steps: (1) Start the equipment to start the turbine blade processing tool to work, detect the speed of the turbine blade processing tool in real time through the speed sensor, and transmit the detected speed signal to the central processing unit; (2) After receiving the speed signal, the CPU calculates the blade wear of the tool used for machining the turbine blade using the following formula: Wherein, W is the blade wear, in mm; K is the cutting fragility coefficient of the tool used for processing steam turbine blades; C is the cutting hardness coefficient of the tool used for processing steam turbine blades; V is the linear speed of the tool used for processing steam turbine blades, in m / min; t is the total working time of the tool used for processing steam turbine blades, in min; a is the empirical coefficient, which is obtained based on the experience of using the tool material; (3) The central processing unit compares the blade wear amount calculated in step (2) with the set wear amount threshold. When the blade wear amount is less than the wear amount threshold, the process goes to step (4). When the blade wear amount reaches the set wear amount threshold, the central processing unit sends an alarm signal to the alarm device and displays the alarm information on the display to remind the staff to replace the tool, thus ending the tool monitoring. (4) The CPU calculates the cutting force of the blade used for machining turbine blades according to the following formula: Among them, F is the cutting force of the blade, the unit is N; V B is the wear correction factor; a p is the cutting depth of the tool, in mm; f is the feed rate of the tool used for machining turbine blades, the unit is mm / r; is the unit cutting force, unit N / mm 2 ; (5) The CPU calculates the service life of the tool used for machining turbine blades according to the following formula: in, S is the service life of the tool used for machining turbine blades, in min; B is the empirical constant of the tool-workpiece system; is the linear speed of the tool used for machining turbine blades, in m / min; n is the impact index of cutting speed on tool life; f is the feed rate of the tool used for machining turbine blades, the unit is mm / r; m is the influence index of feed rate on tool life; a p is the cutting depth of the tool, in mm; p is the influence index of cutting depth on tool life; is the unit cutting force, unit N / mm 2 ; F is the cutting force of the blade, the unit is N; (6) The central processing unit compares the service life of the steam turbine blade processing tool calculated in step (5) with the actual working time of the steam turbine blade processing tool. When the actual working time of the steam turbine blade processing tool reaches the service life of the steam turbine blade processing tool, the central processing unit sends an alarm signal to the alarm device and displays the alarm information on the display to remind the staff to replace the tool, thereby ending the tool monitoring.

7. The monitoring method of a tool status monitoring system for machining steam turbine blades according to claim 6, characterized in that: In step (2), the numerical range of K is 0.001-0.004; the numerical range of C is 0.25-0.40; the numerical range of V is 180-300; and the numerical range of a is 8000-12000.

8. The monitoring method of a tool status monitoring system for steam turbine blade machining according to claim 6, characterized in that: Step (4) V B The value range is 0.1-0.5; a p The value range is 0.5-5; f The value range is 0.05-0.3; The value range is 1800-4000.

9. The monitoring method of a tool status monitoring system for steam turbine blade machining according to claim 6, characterized in that: The value range of B in step (5) is 150-300; The value range is 180-300; n The value range of is 0.1-0.5; f The numerical range of is 0.05-0.3; the numerical range of m is 0.5-0.8; a p The value range of is 0.5-5; the value range of p is 0.1-0.3; The value range is 1800-4000.

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