A pipeline cooling system and control method for a high modulus test bed

Abstract

The application provides a pipeline cooling system and control method for a high mode test bench, which comprises a water spraying system and a control system, the water spraying system comprises a peripheral water spraying system and a central water spraying system, the peripheral water spraying system is a water spraying port arranged on the inner side of the peripheral wall of the diffuser-ejector device, the central water spraying system is a water pipe arranged along the radial direction of the diffuser-ejector device, the two ends of the water pipe are connected with the wall, and a sprayer is arranged on the water pipe, the water spraying system is controlled by the control system, an electric signal is transmitted to a signal conditioning circuit through a thermocouple arranged on the wall of the diffuser-ejector device, the duty cycle is determined through a control chip, and a pulse signal of the duty cycle is sent to an electromagnetic valve through an isolation output circuit to start the water spraying system. The application has the advantages of compact structure, small size, uniform cooling effect, automatic control of water flow according to the real-time temperature of the pipeline, and optimal cooling effect.

Description

Technical Field

[0001] This invention belongs to the field of cooling technology for attitude-guided liquid rocket engine ejector-type high-altitude simulation test benches, and specifically relates to a pipeline cooling system and control method for high-altitude test benches. Background Technology

[0002] Attitude and orbit control liquid rocket engines primarily operate in high-altitude environments, providing power for spacecraft attitude or orbit adjustments. Therefore, high-altitude simulation tests are necessary during the development of attitude and orbit control liquid rocket engines. The ejector-type high-altitude simulation test rig consists of a high-altitude chamber, a diffuser ejector device, and other accessories. The diffuser ejector device can be simplified as a long pipe, directly bearing the high-temperature exhaust plume of the engine, which can reach thousands of degrees Celsius. Therefore, to reduce the heat load on the diffuser ejector device, a pipe cooling system needs to be designed. Currently, pipe cooling systems are generally manually controlled water-cooled, spraying water into the pipe through nozzles on the pipe wall, such as... Figure 1 As shown, multiple water spray nozzles are evenly arranged on the inner wall of the diffuser ejector tube. The water mist sprayed through the nozzles cools the diffuser ejector. The disadvantage of this method is that it requires manual control, and the flow rate is difficult to control, easily leading to excessive water vapor in the pipes, which can backflow into the high-altitude chamber and affect the experiment. Furthermore, from... Figure 1 It is evident that the current cooling method, in which cooling water is sprayed radially inward from the pipe wall, results in uneven cooling of the exhaust flame. Summary of the Invention

[0003] The technical problem solved by this invention is to provide a pipe cooling system for a high-modulus test bench. During the test, water is automatically and uniformly sprayed into the pipe at a certain flow rate to cool it down according to the temperature. This solves the problem that it is difficult to control the flow rate manually, which can easily cause excessive water vapor in the pipe, affecting the test and resulting in uneven cooling effect on the exhaust flame.

[0004] The technical solution adopted in this invention is: a pipe cooling system for a high-performance test bench, comprising a water spray system and a control system. The water spray system includes an outer peripheral water spray system and a central water spray system. The outer peripheral water spray system consists of water nozzles located on the inner circumference of the diffuser ejector tube wall, which are connected to a water supply pipe. The central water spray system consists of a water pipe arranged radially along the diffuser ejector, with both ends connected to the tube wall. Injectors are installed on the water pipe, which is connected to the water supply pipe. The water spray system is controlled by the control system, which includes a power supply, a signal conditioning circuit, an isolation output circuit, and a control chip. The power supply powers the entire control system circuit. Electrical signals are transmitted to the signal conditioning circuit via thermocouples installed on the diffuser ejector tube wall. The control chip determines the duty cycle and sends a pulse signal of the duty cycle to the solenoid valve through the isolation output circuit to start the water spray system.

[0005] Preferably, the control system starts the water spray system after either the temperature detected by the temperature measuring point on the pipe wall of the diffuser ejector device or the start-up temperature rise rate exceeds a predetermined threshold. The control system adopts two sets of control logic, which includes temperature threshold judgment and temperature rise rate judgment. Compared with temperature threshold judgment alone, it has a predictive effect and can cool the pipeline more timely and accurately, reducing the adverse effects on the test.

[0006] Preferably, the injector is located at the center of the cross-section of the diffuser ejector device, the length direction of the injector is consistent with the airflow direction inside the diffuser ejector device, the injector is streamlined and spindle-shaped, with a nozzle on the tail end face, and the middle section is connected to a water pipe, the cross-section of the water pipe is streamlined to reduce the impact on the flow field structure inside the pipe.

[0007] Preferably, the injector has four-sided pyramids at both ends and a rectangular transition section in the middle. Spray holes are evenly distributed on the four triangular faces of the four-sided pyramid at the tail end. The water spray path is radially outward, while the spray holes of the outer peripheral water spray system spray water radially inward, thereby achieving uniform cooling of the tail flame.

[0008] This invention also includes a control method for a pipe cooling system on a high-performance test bench, which automatically controls the opening and closing of a water spray system by continuously processing data in real time through a control system. The specific steps are as follows:

[0009] Step 1: Turn on the power and run the self-test program. If the self-test fails, a buzzer alarm will sound.

[0010] Step 2: After the self-test is normal, collect the detection data of each temperature measuring point on the tube wall of the diffuser ejector device;

[0011] Step 3: Temperature data processing. If the temperature is below the predetermined threshold, proceed to step 4. If the temperature is above the predetermined threshold, proceed directly to step 5.

[0012] Step 4: Temperature rise rate data processing. If the temperature rise rate is lower than the predetermined threshold, return to step 2. If the temperature rise rate is higher than the predetermined threshold, proceed to step 5.

[0013] Step 5: Based on the data processing results, send a pulse signal with the preset duty cycle to the solenoid valve to open the solenoid valve and start the water spray system.

[0014] Step 6: The data from each temperature measuring point is continuously transmitted and processed. When the temperature is lower than the predetermined threshold and the temperature rise rate is also lower than the predetermined threshold, the solenoid valve is closed.

[0015] Preferably, in step 5, the duty cycle is positively correlated with the water flow rate. When the heat load is low, a smaller duty cycle is used to spray water at a lower flow rate; when the heat load is high, a larger duty cycle is used to spray water at a higher flow rate.

[0016] The beneficial effects of this invention are: the invention has a compact structure and small size, and provides uniform cooling effect. It can automatically control the water spray flow rate according to the real-time temperature of the pipeline to achieve the best cooling effect. It adopts two sets of control logic, which include temperature threshold judgment and temperature rise rate judgment. Compared with temperature threshold judgment alone, it has a predictive effect, which can cool the pipeline more timely and accurately, and reduce the adverse effects on the experiment. Attached Figure Description

[0017] Figure 1 A schematic diagram of an existing pipeline cooling system;

[0018] Figure 2 This is a schematic diagram of the pipe cooling system structure of the present invention;

[0019] Figure 3 A schematic diagram of the central water spray system;

[0020] Figure 4 This is a schematic diagram of the injector structure;

[0021] Figure 5 A schematic diagram of the cross-sectional shape of the water pipe;

[0022] Figure 6 This is a general layout diagram of the pipeline cooling system;

[0023] Figure 7 This is the overall circuit design diagram for the control system;

[0024] Figure 8 This is the control flowchart for the control system.

[0025] Attached reference numerals: 1-pipe wall, 2-spray nozzle, 3-water mist, 4-water pipe, 5-sprayer, 6-spray hole. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] The principle of this invention is as follows Figure 6As shown, multiple temperature measuring points are installed inside the diffuser ejector tube. Thermocouples transmit real-time monitoring data from these points to the control system. The control system monitors the temperature and temperature rise rate at each measuring point in real time. When the temperature rise rate (the temperature increase per unit time) exceeds a predetermined threshold or the measuring point temperature is higher than the predetermined threshold, a pulse signal with a certain duty cycle is sent to the solenoid valve to activate the water spray system. When the temperature rise rate is lower than the predetermined threshold and the current measuring point temperature is also lower than the predetermined threshold, the solenoid valve closes, stopping the water spray. Different predetermined thresholds represent different levels of heat load; a higher temperature rise rate or higher measuring point temperature indicates a greater heat load. Corresponding duty cycles are set for different predetermined thresholds. When the heat load is low, a smaller duty cycle is used, resulting in a lower water flow rate; when the heat load is high, a larger duty cycle is used, resulting in a higher water flow rate.

[0028] like Figure 1 and Figure 2 As shown, a pipe cooling system for a high-performance test bench includes a water spray system and a control system. The water spray system includes an outer peripheral water spray system and a central water spray system. The outer peripheral water spray system consists of water nozzles 2 located on the inner side of the circumference of the diffuser ejector tube wall 1. Water mist 3 is evenly distributed radially from the outside to the inside of the nozzles 2. The nozzles 2 are connected to a water supply pipe. The central water spray system consists of a water pipe 4 arranged radially along the diffuser ejector. Both ends of the water pipe 4 are connected to the tube wall 1. An injector 5 is installed on the water pipe 4. The water pipe 4 is connected to the water supply pipe. The injector 5 is located at the center of the cross-section of the diffuser ejector. The length direction of the injector 5 is consistent with the airflow direction inside the diffuser ejector. The end facing the airflow is the head end, and the other end is the tail end. The injector 5 is streamlined, with a spray hole 6 on the tail end face. The middle section is connected to the water pipe 4. In this embodiment, the structure of the injector 5 is as follows: Figure 4 As shown, the injector 5 has four-sided pyramidal ends and a rectangular transition section in the middle. Spray holes 6 are evenly distributed on the four triangular faces of the pyramidal end. The water spray path is radially outward, and the airflow direction is also the direction of the flame emitted by the rocket engine. By placing the spray holes 6 at the tail end of the injector 5, the airflow mixed with flames becomes an airflow mixed with water droplets and flames, achieving a cooling effect. As the airflow is sprayed outward, the heat of the flames turns the water into water vapor, lowering the temperature of the airflow mixed with flames, thus achieving cooling of the flame airflow. If the spray holes 6 were placed at the head end of the injector 5, because the water pressure in the water pipe 4 is higher, and for small rocket engines with lower airflow pressure and less heat carried by the flames, water droplets could easily be sprayed onto the engine outlet, adversely affecting the engine. Simultaneously, the outer peripheral water spray system sprays water radially inward, thereby achieving uniform cooling of the exhaust flame. Figure 5 As shown, the cross-section of the water pipe is streamlined, and both ends, which are in the same direction as the airflow, are designed with sloping surfaces with rounded tops to reduce the impact on the flow field structure inside the pipe.

[0029] The sprinkler system is controlled by a control system, such as... Figure 7 As shown, the control system includes a power supply, a signal conditioning circuit, an isolation output circuit, and a control chip. The power supply powers the entire control system circuit. Electrical signals are transmitted to the signal conditioning circuit via thermocouples mounted on the wall of the diffuser ejector tube 1. The control chip determines the duty cycle and sends a pulse signal of that duty cycle to the solenoid valve through the isolation output circuit, thus activating the water spray system. The control system activates the water spray system when either the temperature detected by the temperature measuring point on the diffuser ejector tube wall or the start-up temperature rise rate exceeds a predetermined threshold. The control system employs two sets of control logic: one for temperature threshold judgment and one for temperature rise rate judgment. Compared to a single temperature threshold judgment, this system provides predictive capabilities, enabling more timely and accurate cooling of the pipeline and reducing adverse effects on the experiment.

[0030] This invention also includes a control method for a pipe cooling system on a high-performance test bench, which automatically controls the opening and closing of a water spray system by continuously processing data in real time through a control system. Figure 8 As shown, the specific steps are as follows:

[0031] Step 1: Turn on the power and run the self-test program. If the self-test fails, a buzzer alarm will sound.

[0032] Step 2: After the self-test is normal, collect the detection data of each temperature measuring point on the tube wall of the diffuser ejector device;

[0033] Step 3: Temperature data processing. If the temperature is below the predetermined threshold, proceed to step 4. If the temperature is above the predetermined threshold, proceed directly to step 5.

[0034] Step 4: Temperature rise rate data processing. If the temperature rise rate is lower than the predetermined threshold, return to step 2. If the temperature rise rate is higher than the predetermined threshold, proceed to step 5.

[0035] Step 5: Based on the data processing results, send a pulse signal with the preset duty cycle to the solenoid valve to open the solenoid valve and start the water spray system. The duty cycle is positively correlated with the water spray flow rate. When the heat load is low, a smaller duty cycle is used to spray water at a lower flow rate; when the heat load is high, a larger duty cycle is used to spray water at a higher flow rate.

[0036] Step 6: The data from each temperature measuring point is continuously transmitted and processed. When the temperature is lower than the predetermined threshold and the temperature rise rate is also lower than the predetermined threshold, the solenoid valve is closed.

[0037] When the invention is working, water enters the water nozzle 2 of the peripheral water spray system and the water pipe 4 of the central water spray system through the water supply pipe, and is sprayed out through the spray hole 6. The spray path of the central water spray system is radially outward, and the spray path of the peripheral water spray system is radially inward, thereby achieving uniform cooling of the tail flame.

[0038] The above describes specific embodiments of the present invention and the technical principles employed. Any modifications or equivalent transformations based on the technical solutions of the present invention should be included within the protection scope of the present invention.

Claims

1. A pipe cooling system for a high-performance test bench, characterized in that: The system includes a water spraying system and a control system. The water spraying system comprises an outer peripheral water spraying system and a central water spraying system. The outer peripheral water spraying system consists of water nozzles located on the inner circumference of the diffuser ejector tube wall, connected to a water supply pipe. The central water spraying system consists of a water pipe arranged radially along the diffuser ejector, with both ends connected to the pipe wall. Injectors are installed on the water pipe, which is also connected to the water supply pipe. The injectors are located at the center of the cross-section of the diffuser ejector, with their length aligned with the airflow direction within the diffuser ejector. The injectors are streamlined, spindle-shaped, and have nozzles on their tail end. The middle section is connected to a water pipe with a streamlined cross-section. The water spray system is controlled by a control system, which includes a power supply, a signal conditioning circuit, an isolation output circuit, and a control chip. The power supply provides power to the entire control system circuit. Electrical signals are transmitted to the signal conditioning circuit through thermocouples installed on the wall of the diffuser ejector. The control chip determines the duty cycle and sends a pulse signal of the duty cycle to the solenoid valve through the isolation output circuit to start the water spray system. The control system starts the water spray system when either the temperature detected by the temperature measuring point on the wall of the diffuser ejector or the start-up temperature rise rate exceeds a predetermined threshold.

2. The pipe cooling system for a high-performance test bench according to claim 1, characterized in that: The injector has four-sided pyramids at both ends and a rectangular transition section in the middle. Spray holes are evenly distributed on the four triangular faces of the four-sided pyramid at the tail end.

3. The control method for a pipeline cooling system for a high-performance test bench according to claim 1, characterized in that, The control system continuously processes data in real time to automatically control the opening and closing of the sprinkler system. The specific steps are as follows: Step 1: Turn on the power and run the self-test program. If the self-test fails, a buzzer alarm will sound. Step 2: After the self-test is normal, collect the detection data of each temperature measuring point on the tube wall of the diffuser ejector device; Step 3: Temperature data processing. If the temperature is below the predetermined threshold, proceed to step 4. If the temperature is above the predetermined threshold, proceed directly to step 5. Step 4: Temperature rise rate data processing. If the temperature rise rate is lower than the predetermined threshold, return to step 2. If the temperature rise rate is higher than the predetermined threshold, proceed to step 5. Step 5: Based on the data processing results, send a pulse signal with the preset duty cycle to the solenoid valve to open the solenoid valve and start the water spray system. Step 6: The data from each temperature measuring point is continuously transmitted and processed. When the temperature is lower than the predetermined threshold and the temperature rise rate is also lower than the predetermined threshold, the solenoid valve is closed.

4. The control method for a pipeline cooling system for a high-performance test bench according to claim 3, characterized in that: In step 5, the duty cycle is positively correlated with the water flow rate. When the heat load is low, a smaller duty cycle is used to spray water at a lower flow rate; when the heat load is high, a larger duty cycle is used to spray water at a higher flow rate.

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