Heat-proof structure heat insulation performance experiment control platform based on PLC technology

Abstract

The invention discloses a PLC technology-based heat insulation performance experiment control platform for a heat-proof structure. The experiment control platform comprises a remote computer, a local console, a switch, a CPU module, a temperature acquisition module, a direct-current power supply power controller, a temperature isolator and a thermocouple, the remote computer and the local console are connected with the switch, the switch is connected with the CPU module and the temperature acquisition module, the CPU module is connected with the DC power supply power controller, the temperature acquisition module is connected with the temperature isolator, and the temperature isolator is connected with the thermocouple. The method can be applied to temperature tracking control of radiation heating in a quartz lamp pneumatic environment, and is of great significance to an aerospace pneumatic thermal environment simulation experiment technology.

Description

Technical Field

[0001] The invention relates to an ultra-high temperature quartz lamp infrared radiation type aerodynamic thermal environment experiment control platform, belonging to the field of aerospace aerodynamic thermal experiments. Background Art

[0002] As the flight speed of aircraft design increases significantly, the high-temperature thermal environment generated by aerodynamic heating becomes more and more severe. The high temperature generated by aerodynamic heat will reduce the strength limit of the material and the bearing capacity of the aircraft structure, causing thermal deformation of the aircraft material, destroying the aerodynamic shape of the components and affecting safe flight. In order to ensure the safety of high-speed aircraft and confirm whether the aircraft material can withstand the thermal shock and high-temperature thermal stress damage generated during high-speed flight, static and dynamic aerodynamic thermal simulation experiments must be carried out on the materials and structures used in high-speed aircraft.

[0003] At the same time, with the continuous development of space technology, the research on spacecraft materials has become one of the key technologies. When a spacecraft flies at high speed through the atmosphere, the surface temperature can change by tens of degrees or even hundreds of degrees per second. The surface temperature field and heat flow field change dramatically during the entire flight. Spacecraft in a heated flight state may also perform highly maneuverable tasks such as sudden acceleration, climbing, turning, and changing orbits, making the relationship between material and structural strength and temperature, heat flow, load and time very complicated. In order to accurately simulate the aerodynamic thermal process of the spacecraft structure during high-speed flight, it is necessary to conduct ground static and dynamic aerodynamic thermal simulation experiments on the materials and structures used in the spacecraft.

[0004] The quartz lamp radiation heater has small thermal inertia and excellent electrical control performance, which is very suitable for high-speed transient pneumatic heating simulation. At the same time, the quartz lamp radiation heater also has the advantages of large heating power, small size, and can be composed of heating devices of different sizes and shapes; it has good adaptability to experimental pieces with complex shapes and structures, and is an ideal radiation heating source for pneumatic heating simulation experiments.

[0005] Quartz lamp infrared radiation heating is an important means of thermal protection testing in the aerospace field. This test requires fast and accurate tracking of heat flow and temperature in a certain flow field, so that the test is meaningful for reference. It is difficult to build an intelligent and fast test platform to meet the test data requirements with traditional solutions, which have the following limitations.

[0006] 1. It cannot realize fast tracking of temperature and heat flow, has time lag, cannot achieve the temperature rise slope within a certain period of time, and cannot meet the thermal structure assessment requirements of specific thermal protection tests;

[0007] 2. The tracking accuracy is inaccurate, the overshoot is large, and the consistency is poor, resulting in the test data being of little reference value. Summary of the invention

[0008] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a heat-proof structure thermal insulation performance experimental control platform based on PLC technology, to collect the surface temperature of the test piece as the controlled quantity of the experimental platform through thermocouples, and to achieve accurate tracking of the nonlinear thermal environment of the heating rate by adopting a feedforward + feedback composite control strategy. The present invention can provide research and development and operation experience for building a higher power and larger size quartz lamp radiation heating test platform, which is of great significance to aerodynamic thermal protection tests in the aerospace field.

[0009] The technical solution of the present invention is:

[0010] The heat insulation performance experiment control platform of heat-resistant structure based on PLC technology includes: remote computer, local console, switch, CPU module, temperature acquisition module, DC power controller, temperature isolator and thermocouple;

[0011] The remote computer and the local console are connected to a switch, the switch is connected to a CPU module and a temperature acquisition module, the CPU module is connected to a DC power supply controller, the temperature acquisition module is connected to a temperature isolator, and the temperature isolator is connected to a thermocouple;

[0012] Thermocouples are used to collect the surface temperature of the heat-resistant material test piece and convert it into an electrical signal to transmit to the temperature isolator;

[0013] The temperature isolator is used to convert the electrical signal sent by the thermocouple into a digital quantity, and transmit the digital quantity as the feedback controlled quantity to the CPU module through the temperature acquisition module;

[0014] The CPU module receives the feedback controlled quantity forwarded by the temperature acquisition module, and receives the set temperature data of the remote computer or the local console as the given value through the switch. The CPU module calculates the power value that the DC power supply needs to output based on the given value and the feedback controlled quantity and outputs it to the DC power supply power controller;

[0015] The DC power supply controller converts the power value that the DC power supply sent by the CPU module needs to output into a thyristor trigger pulse signal, and sends it to the external thyristor DC power supply. By adjusting the output power of the external thyristor DC power supply, the temperature of the experimental environment where the heat-resistant material test piece is located is changed.

[0016] Preferably, the remote computer and the local console are both industrial computers with WINCC monitoring and data acquisition software installed inside; the remote computer and the local console generate curves and record tables with the set temperature data through the visualization window of the WINCC monitoring and data acquisition software.

[0017] Preferably, the temperature isolator is a thermocouple signal isolator.

[0018] Preferably, the temperature isolator is TS5751 produced by Tiantuo Sifang Company.

[0019] Preferably, the CPU module sends the power value required to be output by the DC power supply to the DC power supply power controller via the RS485 interface using the Modbus communication protocol.

[0020] Preferably, the CPU module is a CPU module of the Siemens S7-1500 series PLC.

[0021] Preferably, the switch is connected to the CPU module using industrial Ethernet.

[0022] The advantages of the present invention compared with the prior art are:

[0023] 1) The CPU module of the present invention calculates the power value that the DC power supply needs to output according to the given value and the feedback controlled quantity, and can accurately track the nonlinear thermal environment of the heating rate, providing the necessary experimental conditions for the thermal strength experiment of high temperature, high heat flow and high impact rate.

[0024] 2) The CPU module of the present invention is connected to the temperature acquisition module through the spare board bus, and adopts the industrial communication bus technology, which reduces the number of signal power conversions, greatly reduces signal distortion and line interference, and can improve the accuracy of experimental data. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a system block diagram of a heat-proof structure thermal insulation performance experiment control platform based on PLC technology in one embodiment of the present invention.

[0026] Figure 2 This is the block diagram of the composite control strategy for the experimental control platform.

[0027] Marked in the figure are: 1 remote computer, 2 local console, 3 switch, 4 CPU module, 5 temperature acquisition module, 6 DC power supply controller, 7 temperature isolator, 8 thermocouple. DETAILED DESCRIPTION

[0028] like Figure 1 As shown in the figure, the basic structure and control relationship of the experimental control platform are shown. The heat-proof structure thermal insulation performance experimental control platform based on PLC technology of the present invention comprises: a remote computer 1, a local console 2, a switch 3, a CPU module 4, a temperature acquisition module 5, a DC power controller 6, a temperature isolator 7 and a thermocouple 8. It is mainly used for the construction of the heat-proof structure thermal insulation performance experimental control platform in the aerospace field.

[0029] The remote computer 1 and the local console 2 are both industrial computers, and WINCC monitoring and data acquisition software is installed inside. The remote computer 1 and the local console 2 are connected to a switch 3, and the switch 3 is connected to a CPU module 4 and a temperature acquisition module 5, and the CPU module 4 is connected to a DC power controller 6, and the temperature acquisition module 5 is connected to a temperature isolator 7, and the temperature isolator 7 is connected to a thermocouple 8;

[0030] The thermocouple 8 is used to collect the surface temperature of the heat-resistant material test piece and convert it into an electrical signal to transmit to the temperature isolator 7; the thermocouple 8 is connected to the temperature isolator 7 as a device for collecting the temperature of the test piece.

[0031] The temperature isolator 7 is a thermocouple signal isolator, which is connected between the thermocouple 8 and the temperature acquisition module 5 and is used for signal isolation and conversion. The temperature isolator 7 uses TS5751 from Tiantuo Sifang Company.

[0032] The temperature isolator 7 is used to convert the electrical signal sent by the thermocouple 8 into a digital quantity, and transmit the digital quantity as a feedback controlled quantity to the CPU module 4 through the temperature acquisition module 5;

[0033] The CPU module 4 receives the set temperature data of the remote computer 1 or the local control console 2 as a given value. The CPU module 4 calculates the power value that the DC power supply needs to output according to the given value and the feedback controlled quantity and outputs it to the DC power supply power controller 6;

[0034] The CPU module 4 sends the power value required to be output by the DC power supply to the DC power supply power controller 6 via the RS485 interface using the Modbus communication protocol.

[0035] The DC power supply controller 6 serves as the core of the thyristor DC power supply power control and receives the power value signal of the CPU module 4. The DC power supply controller 6 converts the power value that the DC power supply needs to output sent by the CPU module 4 into a thyristor trigger pulse signal through PID calculation and sends it to the external thyristor DC power supply. By adjusting the output power of the external thyristor DC power supply, the temperature of the experimental environment in which the heat-resistant material test piece is located is changed.

[0036] The CPU module 4 is a CPU module of the S7-1500 series PLC of Siemens.

[0037] The switch 3 is connected to the CPU module 4 using industrial Ethernet, so that the CPU module 4 can achieve data communication with the remote computer 1 and the local console 2.

[0038] The remote computer 1 and the local console 2 are used to generate curves and record tables with the set temperature data through the visualization window of the WINCC software, and to monitor the operation of the experimental platform in real time.

[0039] Temperature acquisition module 5 is the analog input acquisition module of S7-1500 series PLC.

[0040] The CPU module 4 is connected to the temperature acquisition module 5 via the standby board bus, and receives the temperature signal after analog-to-digital conversion by the temperature acquisition module 5 as a feedback controlled variable.

[0041] The CPU module 4 receives the set temperature data sent by the remote computer 1 or the local control console 2 as a given value, and collects the temperature signal from the temperature acquisition module 5 as a feedback controlled quantity. Through a control algorithm combining feedforward and feedback, the power value that the DC power supply needs to output is calculated, and the value is sent to the DC power supply power controller 6 through the RS485 interface using the Modbus communication protocol, thereby achieving accurate tracking of the nonlinear thermal environment of the heating rate.

[0042] like Figure 2 As shown, Figure 1 The remote computer 1, local console 2, and switch 3 in the system are used as feedforward controllers, and the CPU module 4 and temperature acquisition module 5 are used as feedback controllers. The present invention realizes accurate tracking of the quartz lamp infrared radiation pneumatic nonlinear thermal environment. The set temperature is collected into the PLC, and a feedforward + feedback composite control method (such as Figure 2 The power supply output power is calculated and sent to the DC power supply controller to adjust the output power of the DC power supply, thereby achieving accurate tracking of the nonlinear thermal environment of the heating rate.

[0043] The present invention is intelligent. It only needs to input the set temperature curve into WINCC and set the experimental time. After the experiment starts, the control platform sets the parameters to automatically run and collect key parameters such as temperature, heat flow, current, voltage, etc. in real time for archiving. When the set experimental time is reached, the operation is automatically stopped.

[0044] The present invention has visibility and can generate parameters such as set temperature into a curve that changes with time through the screen configuration software WINCC. The horizontal axis of the curve is time and the vertical axis is each parameter value. The data fit and key point parameter comparison are more intuitive.

[0045] The present invention can be applied to the temperature tracking control of radiation heating in a pneumatic environment of a quartz lamp, and comprises the following steps:

[0046] Step 1: Install WINCC monitoring and data acquisition software in the remote computer 1 and the local console 2. Generate curves and record tables with the set temperature data through the visualization window of the WINCC software, and monitor the operation of the experimental platform in real time. The experimental platform adopts quartz lamp infrared radiation heating.

[0047] Step 2: The switch 3 is connected to the CPU module 4 using industrial Ethernet, receives the temperature control curve set by the remote computer 1 or the local console 2, and transmits it to the CPU module 4.

[0048] Step 3, the CPU module 4 selects to receive the set temperature data sent by the remote computer 1 or the local console 2 as a given value through the program, and sends it to the CPU module 4 through the switch 3;

[0049] Step 4: Thermocouple 8 collects the surface temperature of the heat-resistant material test piece, and converts it into an electrical signal and transmits it to temperature isolator 7. Temperature isolator 7 converts the converted 4-20mA thermocouple signal into a digital quantity, and transmits the digital quantity as a feedback controlled quantity through temperature acquisition module 5 to CPU module 4;

[0050] Step 5: The CPU module 4 uses the temperature signal of the heat-resistant material test piece collected by the temperature acquisition module 5 as the feedback controlled variable, and uses a control algorithm combining feedforward and feedback (see Figure 2 , i.e., composite control strategy), calculates the power value that the DC power supply needs to output, and sends the value to the DC power supply power controller 6 through the RS485 interface using the Modbus communication protocol, thereby achieving accurate tracking of the nonlinear thermal environment of the heating rate. That is, the CPU module 4 is used for the composite control strategy to calculate the power value that the DC power supply needs to output, and realizes the rapid tracking and adjustment of the DC power supply power controller 6.

[0051] Switch 3 is a device for expanding the network and provides more terminal device interfaces for the local area network.

[0052] Temperature acquisition module 5 is an analog input acquisition module of S7-1500 series PLC produced by Siemens, with 8 channels, 16-bit analog-to-digital conversion resolution, and conversion time of ms level.

[0053] The temperature isolator 7 is a thermocouple signal isolator, and the TS5751 purchased from Tiantuo Sifang Company is selected. The temperature isolator 7 is connected between the thermocouple 8 and the temperature acquisition module 5, and is used for signal isolation and conversion. Through reliable isolation between power supply, input and output, it effectively solves the on-site interference problem of the industrial automation control system and ensures the stable and reliable operation of the system.

[0054] The thermocouple 8 is connected to the temperature isolator 7 as a device for collecting the temperature of the test piece, and converts the surface temperature of the test piece into an electrical signal.

[0055] The present invention is used to accurately track the nonlinear thermal environment: the set temperature is set to the PLC, and the feedforward + feedback composite control method (such as Figure 2 The output power of the power supply is calculated (as shown) and sent to the DC power supply controller through the RS485 interface to adjust the output power of the DC power supply, thereby achieving accurate tracking of the nonlinear thermal environment of the heating rate, and providing the necessary experimental conditions for high temperature, high heat flow, and high impact rate thermal strength experiments.

[0056] The present invention only needs to input the set temperature curve into WINCC and set the experimental time. After the experiment starts, the control platform changes the set parameters and automatically runs and collects key parameters such as temperature, heat flow, current, voltage, etc. in real time for archiving. When the set experimental time is reached, the operation is automatically stopped.

[0057] The present invention adopts the screen configuration software WINCC to generate the set temperature and other parameters into a curve changing with time, the horizontal axis of the curve is time, and the vertical axis is each parameter value, and the data consistency and key point parameter comparison are more intuitive.

[0058] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall belong to the protection scope of the technical solution of the present invention. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0059] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. The heat insulation performance experimental control platform of heat-resistant structure based on PLC technology is characterized by: include: Remote computer (1), local console (2), switch (3), CPU module (4), temperature acquisition module (5), DC power supply controller (6), temperature isolator (7) and thermocouple (8); The remote computer (1) and the local console (2) are connected to a switch (3), the switch (3) is connected to a CPU module (4) and a temperature acquisition module (5), the CPU module (4) is connected to a DC power supply controller (6), the temperature acquisition module (5) is connected to a temperature isolator (7), and the temperature isolator (7) is connected to a thermocouple (8); The thermocouple (8) is used to collect the surface temperature of the heat-resistant material test piece and convert it into an electrical signal to be transmitted to the temperature isolator (7); The temperature isolator (7) is used to convert the electrical signal sent by the thermocouple (8) into a digital quantity, and transmit the digital quantity as a feedback controlled quantity to the CPU module (4) through the temperature acquisition module (5); The CPU module (4) receives the feedback controlled quantity forwarded by the temperature acquisition module (5), and receives the set temperature data of the remote computer (1) or the local control console (2) as a given value through the switch (3). The CPU module (4) calculates the power value that the DC power supply needs to output based on the given value and the feedback controlled quantity, and outputs it to the DC power supply power controller (6); The DC power supply controller (6) converts the power value that the DC power supply sent by the CPU module (4) needs to output into a thyristor trigger pulse signal, and sends it to an external thyristor DC power supply, thereby changing the temperature of the experimental environment in which the heat-resistant material test piece is located by adjusting the output power of the external thyristor DC power supply.

2. The heat-insulating performance experimental control platform of heat-resistant structure based on PLC technology according to claim 1 is characterized in that: The remote computer (1) and the local console (2) are both industrial computers with WINCC monitoring and data acquisition software installed inside; the remote computer (1) and the local console (2) generate curves and record tables with the set temperature data through the visualization window of the WINCC monitoring and data acquisition software.

3. The heat-proof structure thermal insulation performance experimental control platform based on PLC technology according to claim 1 is characterized in that: The temperature isolator (7) is a thermocouple signal isolator.

4. The heat-proof structure thermal insulation performance experimental control platform based on PLC technology according to claim 3 is characterized in that: The temperature isolator (7) uses TS5751 produced by Tiantuo Sifang Company.

5. The heat-insulating performance experimental control platform for heat-resistant structures based on PLC technology according to any one of claims 1 to 4, characterized in that: The CPU module (4) transmits the power value required to be output by the DC power supply to the DC power supply power controller (6) via the RS485 interface and using the Modbus communication protocol.

6. The heat-insulating performance experimental control platform of heat-resistant structure based on PLC technology according to claim 5 is characterized in that: The CPU module (4) is a Siemens S7-1500 series PLC CPU module.

7. The heat-insulating performance experimental control platform of heat-resistant structure based on PLC technology according to claim 6 is characterized in that: The switch (3) is connected to the CPU module (4) using industrial Ethernet.

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