A heat flow control system for solid rocket engine coupling test

Abstract

The application provides a heat flow control system for solid rocket engine test. Controllable silicon in the heating module controls the power supply for the heater. Controllable silicon trigger board triggers the control of the heater by the controllable silicon. Heat flow density and temperature sensors respectively transmit the detected heater heat flow density signal and temperature signal to the data acquisition module. The host computer reads the heat flow density and temperature data from the data acquisition module, and respectively controls the heat flow density and temperature parameters in a closed loop. The signal output module converts the heating control signal into an analog signal for controlling the controllable silicon trigger board. The heater includes two layers of quartz lamps, the lamp tubes are staggered and parallel, and the host computer judges the heat flow density value and can output the selected heater arrangement parameters meeting the requirements. The application can select the optimal heater arrangement parameters according to different heating temperature requirements before the test, thereby meeting the heat control requirements of the radiation heat flow distribution and large heating power of the solid rocket engine thermal environment simulation test bed.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal environment simulation of solid rocket engines, and in particular relates to a heat flow control system for solid rocket engine tests. Background Art

[0002] As solid rockets continue to increase in speed, their engines are subject to a harsh aero-thermal environment while traveling at high speed within the atmosphere. The aero-heating problem of solid rocket motor cases will become even more severe. The various properties of the steel and composite materials used in motor cases will degrade under aero-heating. Therefore, the need for research on aero-thermal analysis of solid rocket motor cases and the corresponding thermal protection is becoming increasingly urgent.

[0003] Currently, there are two approaches to studying engine aerodynamic heating. One is airflow heating, which primarily involves two experimental methods: flight tests and ground-based wind tunnel tests. The other is radiation heating. Flight tests are expensive, have a limited number of flights, and produce scant test data. Furthermore, measurement instrumentation inevitably introduces errors, making it difficult to obtain complete and accurate data. Ground-based wind tunnel tests allow for direct measurement of thermal environment parameters with controllable accuracy. However, due to limitations in model scale and incoming flow conditions, they cannot simulate actual flight conditions, and therefore cannot produce accurate aerodynamic data.

[0004] Compared to airflow heating, radiation heating offers more economical equipment construction and operation costs, and offers unique advantages for addressing heat transfer, thermal deformation, thermal matching, and structural integrity in complex environments for solid rocket motor structures. This heating method primarily utilizes a computer-controlled infrared radiation heating system, employing quartz lamps, graphite, and other radiation heating devices to replicate the heat transfer characteristics of the solid rocket motor's external surface under actual operating conditions. Furthermore, during ground testing, the test piece can be segmented and zoned to simulate the thermal environment according to actual flight aerodynamic heating loads and temperature distribution. Therefore, radiation heating testing, which seamlessly integrates computer and ground simulation equipment, is the only method capable of conducting multi-temperature zone, time-dependent, and full-scale / whole-unit thermal testing.

[0005] However, existing ground simulation equipment, whether using a single constant temperature heating or constant heat flux heating mode, or an adaptive heating mode, is unable to meet the thermal control requirements of the solid rocket engine thermal environment simulation test bench for uniform radiation heat flux distribution and large heating power. Summary of the Invention

[0006] In order to solve the problem that the existing solid rocket engine thermal environment ground simulation equipment is difficult to meet the thermal control requirements of the solid rocket engine thermal environment simulation test bench when conducting radiation heating tests, the present invention proposes a heat flux control system for solid rocket engine coupling tests, which can realize the temperature and heat flux density acquisition and processing of the surface of the heated object and feedback control, and gradually meet the test capability requirements of the solid rocket engine for uniform radiation heat flux distribution and large heating rate.

[0007] Furthermore, during the heater simulation design and experimental process, the applicant analyzed the effects of different parameters on the radiant heat flux distribution and heater power density based on the simulation calculation results of the radiant heat flux density distribution on the specimen surface. It was found that the three parameters, namely the lamp tube layer spacing, the spacing between adjacent quartz lamps, and the distance between the heater and the specimen, and the relationship between them, have a significant impact on the radiant heat flux distribution and heater power density. When these parameters are within a certain range, a higher heat flux density can be achieved. At the same time, when the distance between the heater and the specimen is greater than the spacing between adjacent quartz lamps, the quartz lamp spacing mainly affects the heater power density and has little effect on the radiation distribution. When the quartz lamp spacing is close to or even greater than the distance between the heater and the specimen, a radiation valley phenomenon occurs between the quartz lamps. This phenomenon needs to be avoided to ensure that a certain radiation uniformity is maintained even when the heater power density is high. In response to this discovery, the applicant designed and determined the appropriate ranges for these parameters. During the simulation test, these parameters can be adjusted within the designed range according to the heat flux control target to select the optimal parameters to meet the thermal control requirements of the solid rocket engine thermal environment simulation test bench.

[0008] To achieve the above objectives, the technical solutions provided by the present invention are:

[0009] A heat flux control system for solid rocket engine testing, comprising a host computer, a heating module, a thyristor trigger board, a heat flux density sensor, a temperature sensor, a data acquisition module, a signal output module, and an interaction module;

[0010] The heating module includes a heater, a thyristor and a power supply. The thyristor controls the power supply to supply power to the heater to heat the engine test piece.

[0011] The thyristor trigger board is used to trigger the thyristor to control the heater;

[0012] The heat flux density sensor is used to detect the heat flux density of the heater and transmit the detected heat flux density signal to the data acquisition module, and one is arranged at the center of each layer of quartz lamps;

[0013] The temperature sensor is used to detect the heating temperature of the heater and transmit the detected temperature signal to the data acquisition module;

[0014] The host computer reads the heat flux data and temperature data from the data acquisition module, calculates and processes the temperature data, and outputs a heating control signal;

[0015] The signal output module converts the heating control signal into an analog signal for controlling the thyristor trigger board;

[0016] The heater includes two layers of quartz lamps, one above the other. The quartz lamps in the two layers are staggered and arranged in parallel. The heater is arranged according to the selected heater layout parameters, which include the distance between the lamp tube layers, the distance between adjacent quartz lamps in each layer, and the distance between the heater and the engine test piece. The host computer determines the read heat flux density value. If it does not meet the requirements, the interactive module outputs the selected heater layout parameters that meet the requirements under the following constraints: the range of the distance between the lamp tube layers is 0-20mm, the range of the distance between adjacent quartz lamps in each layer is 10-30mm, and the range of the distance between the heater and the engine test piece is 90-110mm.

[0017] Furthermore, the host computer adopts an intelligent PID control method based on deep reinforcement learning to achieve real-time temperature control.

[0018] Furthermore, the interactive module can be used to set the heating temperature and the time for maintaining the heating temperature stably.

[0019] Furthermore, the interactive module can be used to set the required heat flux density.

[0020] Furthermore, the interactive module can display the curve of heat flux density changing with time.

[0021] The advantages of the present invention are:

[0022] 1. The heat flux control system for solid rocket engine testing of the present invention is provided with a heat flux density sensor for collecting the heat flux density of the heater and a temperature sensor for collecting the heating temperature of the heater. The temperature sensor can be used to determine whether the heating temperature meets the expected temperature requirement. The heat flux density sensor can be used to select appropriate layout parameters of the heater. At the same time, the structural and layout parameter constraints of the heater are also defined. Before the test, the optimal heater layout parameters can be selected under the constraints for different heating temperature requirements, thereby meeting the thermal control requirements of the solid rocket engine thermal environment simulation test bench for radiation heat flux distribution and large heating power.

[0023] 2. Temperature control is achieved by adopting an intelligent PID control method based on deep reinforcement learning, which can achieve fast and stable temperature rise control. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or other features and advantages of the present invention will become more readily understood through the following description with reference to the accompanying drawings, which are not drawn to scale and in which some features are exaggerated or minimized to show details of particular components.

[0025] Figure 1 is a diagram of the composition of a heat flow control system for solid rocket engine testing according to the present invention;

[0026] Figure 2 is a perspective view of the heater of the present invention;

[0027] Figure 3 is a front view of the heater of the present invention;

[0028] Figure 4 These are simulated cloud diagrams of the radiation heat flux density distribution under different lamp tube interlayer spacings in the present invention, where the lamp tube interlayer spacing in (a) is 0 mm, the lamp tube interlayer spacing in (b) is 10 mm, the lamp tube interlayer spacing in (c) is 20 mm, and the lamp tube interlayer spacing in (d) is 40 mm.

[0029] Figure 5 These are simulated cloud diagrams of the radiation heat flux density distribution under different lamp spacings in the present invention, where the quartz lamp spacing in (a) is 20 mm, the quartz lamp spacing in (b) is 40 mm, the quartz lamp spacing in (c) is 60 mm, and the quartz lamp spacing in (d) is 80 mm.

[0030] Figure 6 It is a schematic cloud diagram of the trough of radiation heat flow between quartz lamps in the present invention;

[0031] Figure 7 These are simulated cloud diagrams of the radiation heat flux density distribution at different heater-specimen distances in the present invention, where the heater-specimen distance in (a) is 50 mm, the heater-specimen distance in (b) is 100 mm, the heater-specimen distance in (c) is 150 mm, and the heater-specimen distance in (d) is 200 mm.

[0032] Figure 8 It is a control software panel diagram of the present invention;

[0033] Figure 9 1 is a test site diagram of the present invention in an example, wherein (a) and (b) are diagrams of the heater before and during the test, respectively;

[0034] Figure 10 1 is the experimental data curve of the present invention in the example, wherein (a) and (b) are the data curves of two experiments respectively, wherein the black line is the heat flux density curve, and the other lines are the temperature monitoring points at different positions. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings by means of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is only for the purpose of illustration and is not intended to limit the present invention.

[0036] First refer to Figure 1 The thermal flux control system for solid rocket engine testing provided by the present invention includes a host computer, a heating module, a thyristor trigger board, a heat flux density sensor, a temperature sensor, a data acquisition module, a signal output module and an interaction module.

[0037] The heating module consists of a heater, a thyristor (SCR), and a power supply connected in series to form the heating portion of the system. The thyristor controls the power supply to the heater, heating the engine test specimen. The thyristor linearly controls the heater's output voltage, thereby controlling its output power.

[0038] The thyristor trigger board is used to trigger the thyristor to control the heater. A heat flux sensor is located at the center of each layer of quartz lamps, detecting the heater's heat flux and transmitting the detected heat flux signal to the data acquisition module. A temperature sensor detects the heater's heating temperature and transmits the detected temperature signal to the data acquisition module. The host computer reads the heat flux and temperature data from the data acquisition module, calculates and processes the temperature data, and outputs a heating control signal. The signal output module converts the heating control signal into an analog signal used to control the thyristor trigger board.

[0039] The closed-loop control part consists of a thyristor trigger board, a data acquisition module, a signal output module, and a host computer (industrial computer or desktop computer). The voltage signal output by the heat flux density sensor is collected by the data acquisition module and read by the host computer. After calculation and processing, the host computer outputs the target signal, which is converted into an analog signal (voltage signal) of a certain specification through the signal output module to control the thyristor trigger board. After receiving this voltage signal, the thyristor trigger board outputs a control signal to the thyristor to control the voltage of the heater. As Figure 1 As shown, the heat flow control system forms a closed loop.

[0040] The interactive module can be used to set the heating temperature and the time it will be maintained at that temperature. It can also display the current heating temperature. The interactive module can also be used to set the desired heat flux density and display the heat flux density curve over time.

[0041] like Figure 2 and Figure 3As shown, the heater includes two layers of quartz lamps, one above the other. Each layer of lamp arrays can include multiple, for example, more than ten, quartz lamp tubes. The quartz lamp tubes in the two layers are staggered and arranged in parallel. The heater is arranged according to selected heater layout parameters at different temperatures in different heating stages. The heater layout parameters include the spacing between the tube layers, the spacing between adjacent quartz lamps in each layer, and the distance between the heater and the engine test piece. The host computer can determine the read heat flux value. If it does not meet the requirements, the interactive module outputs the selected heater layout parameters that meet the requirements under the constraints. If it meets the requirements, it indicates that the heater layout parameters are appropriate, and a compliance prompt can be output to prompt the operator to proceed with the test.

[0042] The constraints of the above-mentioned structure and arrangement parameters of the heater are determined by simulation calculations for the following heat radiation distribution.

[0043] Reference Figure 4 , which shows the radiant heat flux density distribution cloud map under different lamp layer spacing. The heat flux density range of the four figures is the same, all 30~38.5kW / m2. Figure 4 (a) shows the radiation heat flux distribution when the interlayer spacing is 0 mm, and the radiation is relatively uniform on the main heating surface. Figure 4 (b) shows the distribution of radiant heat flux generated by the heater when the interlayer spacing is 10 mm. The heat flux density on the specimen surface is mainly concentrated in the range of 34 to 38 kW / m2, with a maximum unevenness of about 10%. In contrast, Figure 4 As shown in (c) and (d) in the figure, as the interlamellar spacing increases, the edge effect between the heater layers becomes more pronounced, and the overall radiation efficiency decreases, manifesting as a decrease in the mean heat flux density. In particular, when the interlamellar spacing reaches 40mm, the local radiation heat flux density at the center of the plate is approximately 31kW / m2, which is significantly different from the peak heat flux density. In fact, the 40mm interlamellar spacing is only twice the length of the ceramic head of a typical quartz lamp. Therefore, if the quartz lamps are aligned according to their actual length (not the luminous length or filament length), a large radiation trough area will form in the middle of the plate, seriously affecting the uniformity of the radiation heat flux density distribution. The size of the interlamellar spacing is a very sensitive factor influencing the radiation distribution of multi-layer quartz lamp heaters. To this end, the light-emitting sections of the two layers of quartz lamps, that is, the ends of the filaments, need to be as close as possible (to ensure that the distance between the filament end layers is between 0 and 20 mm) to avoid the occurrence of radiation troughs caused by edge effects; considering the tooling and wiring issues of quartz lamps, in order to minimize the distance between the lamp tube layers, the two layers of lamp tubes usually need to be staggered.

[0044] Reference Figure 5, shows the radiation distribution cloud map under different quartz lamp spacing. Except for the different quartz lamp spacing, other arrangement parameters are the same, namely: the distance between the heater and the flat specimen is 100mm, and the distance between the lamp layers is 10mm; the number of quartz lamps varies with the lamp spacing, so that the heater area is similar. As can be seen from the figure, when the distance between the heater and the flat specimen is the same and this distance is greater than the quartz lamp spacing, the quartz lamp spacing mainly affects the heater power density, but has little effect on the radiation distribution. Figure 5 As shown in (a), (b), and (d), halving the density of the quartz lamps results in a similar halving of the radiant heat flux density on the specimen surface, while maintaining a similar distribution. Therefore, when the distance between the heater and the heated specimen is greater than the lamp spacing, the lamp spacing primarily affects the heater's radiant power density, with an approximately inversely proportional relationship. In actual testing, if the lamp spacing is too small, such as 10mm, the lamps will be placed close together (the outer diameter of the lamp tube cross section is 10mm), resulting in overheating and damage due to the excessive power density. If this damages the quartz lamps, the heater will require air cooling or even water cooling.

[0045] In addition, if Figure 6 As shown in the figure, when the distance between the quartz lamps approaches or even exceeds the distance between the heater and the flat specimen, a radiation dip occurs between the lamps. In this case, the distance between the lamps is 80mm, and the distance between the heater and the flat specimen is 50mm. The radiation heat flux density is higher in the area facing the lamps, while the radiation heat flux density between the lamps is lower. Although the heat flux density in the radiation dip shown in this figure is not much different from the peak heat flux (approximately 3kW / m²), this phenomenon is generally avoided to ensure a certain degree of radiation uniformity even at high heater power densities.

[0046] Reference Figure 7 , which shows the distribution of radiant heat flux density at different heater-specimen distances. The lamp arrangement and other parameters remain the same, that is, the distance between adjacent quartz lamps is 40mm, and the distance between lamp layers is 10mm. Properly increasing the distance between the heater and the specimen can optimize the uniformity of the radiant heat flux, but will result in a decrease in the heat flux density at the flat plate. Figure 7As shown in (a), when the heater is 50 mm away from the specimen, the 10 mm gap between the lamp layers (the non-luminous section) causes a dip in interlaminar radiation. Although the value of this dip is close to the peak, this result still indicates that when the heater is close to the flat specimen, the radiation dip caused by the distance between the lamp layers and the spacing between adjacent quartz lamps becomes more pronounced. The radiation dip can only be eliminated when the heater-to-specimen distance is greater than both of these factors. Therefore, in practical designs, both the distance between the lamp layers and the spacing between the quartz lamps need to be considered comprehensively. The heater-to-specimen distance should not be too small. As mentioned earlier, the distance between the lamp layers is limited by actual assembly and wiring conditions, while the spacing between the quartz lamps is determined by the target heating power density and the heat resistance of the quartz lamps. The radiant heat flux distribution shown in the figure is relatively uniform, but the average radiant heat flux decreases significantly with increasing heater-to-specimen distance.

[0047] Based on the simulation results above, the heater layout parameter constraints can be determined as follows: the spacing between lamp layers ranges from 0-20mm, the spacing between adjacent quartz lamps in each layer ranges from 10-30mm, and the distance between the heater and the engine test piece ranges from 90-110mm, preferably 100mm. Before the test, once the target engine heating temperature is known, the heater layout parameters can be adjusted to achieve the optimal heat flux density at the expected heating temperature, thereby meeting the test's thermal control requirements for radiant heat flux distribution and high heating rates.

[0048] The software configuration, control, and display of the closed-loop system can be implemented in LabVIEW. The control algorithm is based on an intelligent PID control method using deep reinforcement learning. This algorithm interacts with the external environment through reinforcement learning, adjusting PID parameters based on system status to achieve real-time temperature control. Time-segmented control and stable heating are also implemented in LabVIEW, enabling rapid, timely, and stable heating.

[0049] Reference Figure 8 , which shows the LabVIEW front panel, which is used to set the heat flow control target and monitor the collected heat flow in real time. The front panel of the software consists of two parts: "Settings" and "Display". In the "Settings" part, users can set the required heat flow or temperature value according to the test requirements, as well as the time to maintain the value. In the "Display" part, the current heating stage number (current heating temperature) and its target value and stabilization time are displayed in the value box, the heat flow or temperature change over time is displayed in the curve chart, and the heat flow or temperature control curve is displayed in the white box.

[0050] As described above, the present invention is provided with a heat flux density sensor for collecting the heat flux density of the heater and a temperature sensor for collecting the heating temperature of the heater. The temperature sensor can be used to determine whether the heating temperature meets the expected temperature requirement. The heat flux density sensor can be used to select appropriate layout parameters of the heater. At the same time, the structural and layout parameter constraints of the heater are also limited. Before the test, the optimal heater layout parameters can be selected under the constraints according to different heating temperature requirements, thereby meeting the thermal control requirements of the solid rocket engine thermal environment simulation test bench for radiation heat flux distribution and large heating power.

[0051] The solid rocket motor coupled test heat flux control system provided by this invention has been verified by experimental measurement data to demonstrate the strong adaptability and accuracy of the quartz lamp array radiation model. This model can be quickly and easily modified for heaters with different geometric arrangements and different quartz lamps (size, power, etc.), yielding accurate simulated heat flux density results. The multi-domain coupled calculation method for the specimen temperature field is also universal, enabling precise calculation of the specimen surface temperature field based on the aforementioned radiation distribution. This approach achieves the goal of real-time, rapid, and precise computer control of the quartz lamp heating power, thereby achieving uniform heat flux or temperature, as well as rapid and stable temperature rise control.

[0052] This system and its design scheme can also provide design and test experience for ground-based simulated thermal loading of various high-speed aircraft shells; the simulation calculation scheme also provides solutions for heater design of similar problems, and the simulation results and analysis play an important guiding role in heater design.

[0053] Next, the thermal flow control system for solid rocket engine testing provided by the present invention will be further described through examples.

[0054] Reference Figure 9 In this example, the upper and lower layers of the heater's lamp arrays consist of 15 quartz lamps, with a 30mm spacing between adjacent lamps. The length of the quartz lamp's light-emitting segment is 380mm, and the spacing between the light-emitting segments between layers is 10mm. The lamps need to be staggered. The size of the flat specimen is 500×600mm. An intelligent PID control method based on deep reinforcement learning is used to achieve temperature control.

[0055] The key to this design is to keep the interlayer spacing of the quartz lamp's light-emitting segments approximately 10 mm. To this end, since the ceramic head of a quartz lamp is approximately 2 cm long, the lamps are typically staggered. Second, the distance between the edge of the quartz lamp heater and the flat plate should be approximately the same as the distance between the heater plane and the specimen surface to prevent heater edge effects from affecting radiation uniformity. In this design, the lamp ends extend 85 mm beyond the specimen, while the heater is 100 mm from the specimen surface; this difference should not be too large. With a single quartz lamp power of 1500 W and a 40 mm spacing between the lamps, the flat plate's radiant heat flux density can reach up to 50 kW / m². To increase the heat flux density, the lamp spacing can be appropriately reduced or the lamp power increased. However, if the heater power density is too high, cooling measures should be considered. Simulation results and experimental experience indicate that this heater's structural design can meet the target of a radiant heat flux uniformity of less than 10% across the flat plate specimen surface. When the flat plate is positioned horizontally, due to internal heat conduction, the temperature uniformity is better than the radiant heat flux uniformity.

[0056] like Figure 10 As shown in the heat flux density curve data of the two test curves (a) and (b), the heat flux density rises rapidly during control, is stable in the flat section, and does not fluctuate significantly in the descending section. The test results show that the control program of the heat flux control system of the present invention responds quickly, the heat flux control is precise and stable, and can achieve the expected control target, verifying the effectiveness of the heat flux control system provided by the present invention.

[0057] Finally, it should be noted that the features mentioned and / or illustrated in the above description of the exemplary embodiments of the present invention may be incorporated into one or more other embodiments in the same or similar manner, combined with features in other embodiments, or substituted for corresponding features in other implementations. The technical solutions obtained by such combination or substitution shall also be deemed to be included in the scope of protection of the present invention.

Claims

1. A thermal flow control system for solid rocket engine testing, characterized by: It includes a host computer, a heating module, a thyristor trigger board, a heat flux density sensor, a temperature sensor, a data acquisition module, a signal output module and an interaction module; The heating module includes a heater, a thyristor and a power supply, wherein the thyristor controls the power supply to supply power to the heater to heat the engine test piece; The thyristor triggering board is used to trigger the thyristor to control the heater; The heat flux density sensor is used to detect the heat flux density of the heater and transmit the detected heat flux density signal to the data acquisition module, and one heat flux density sensor is arranged at the center of each layer of quartz lamps; The temperature sensor is used to detect the heating temperature of the heater and transmit the detected temperature signal to the data acquisition module; The host computer reads the heat flux data and temperature data from the data acquisition module, calculates and processes the temperature data, and outputs a heating control signal; The signal output module converts the heating control signal into an analog signal for controlling the thyristor trigger board; The heater includes two layers of quartz lamps, one above the other, which are staggered and arranged in parallel. The heater is arranged according to selected heater layout parameters, which include the spacing between lamp tube layers, the spacing between adjacent quartz lamps in each layer, and the distance between the heater and the engine test piece. The host computer determines the read heat flux density value. If it does not meet the requirements, the interactive module outputs the selected heater layout parameters that meet the requirements under the following constraints: the range of the lamp tube layer spacing is 0-20 mm, the range of the spacing between adjacent quartz lamps in each layer is 10-30 mm, and the range of the distance between the heater and the engine test piece is 90-110 mm.

2. The thermal flow control system for solid rocket engine testing according to claim 1, characterized in that: The host computer adopts an intelligent PID control method based on deep reinforcement learning to achieve real-time temperature control.

3. The thermal flow control system for solid rocket engine testing according to claim 1 or 2, characterized in that: The interactive module can be used to set the heating temperature and the time to stably maintain the heating temperature.

4. The thermal flow control system for solid rocket engine testing according to claim 1 or 2, characterized in that: The interactive module can be used to set the desired heat flux density.

5. The thermal flow control system for solid rocket engine testing according to claim 1 or 2, characterized in that: The interactive module can display a curve of heat flux density changing over time.

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