Cooling method for spectral acquisition system in high temperature environment

Abstract

The application belongs to a kind of liquid rocket engine exhaust plume spectrum acquisition system cooling equipment technical field under high temperature, specifically relates to the design and optimization of cooling system of spectrum acquisition system, which comprises the following steps: (1) using thermocouple equipment to measure the temperature field distribution characteristics within a certain distance around the liquid rocket engine test; (2) according to the test stand temperature field data and the heat resistance of spectrum acquisition equipment itself, determine the safety boundary of acquisition system; (3) using active and passive composite cooling method to cool the exhaust flow light measuring equipment, so that the light measuring equipment can be as close as possible to the engine exhaust flow; (4) using numerical simulation and experimental research, research and optimization iteration of cooling scheme of acquisition system; (5) using modular design idea, the cooling scheme after optimization meets the requirements of final design. The application can guarantee the normal operation of light measuring equipment under high temperature environment around the exhaust plume by using the optimization iteration mode of simulation and modeling combination; at the same time, the modular design can flexibly cope with the cooling demand of multi-spectrum acquisition system.

Description

Technical Field

[0001] This invention belongs to the technical field of cooling equipment for a liquid rocket engine exhaust flame spectral acquisition system at high temperatures, specifically involving the design and optimization of the cooling system for the spectral acquisition system. Background Technology

[0002] Liquid rocket engines are a crucial subsystem of launch vehicles, providing power to the rocket. Their successful operation and the success of a space launch are directly dependent on them; therefore, fault diagnosis can effectively improve engine reliability and safety. Using exhaust plume spectroscopy for health monitoring of liquid rocket engines offers advantages such as non-invasiveness, broad information coverage, low false alarm rate, and high sensitivity.

[0003] To obtain accurate and detailed spectral data, the spectral acquisition system should be positioned as close as possible to the exhaust flame. However, the high-temperature operating environment around the exhaust flame necessitates a cooling system to ensure the normal operation of the optical measurement equipment. Traditional liquid cooling methods are relatively simple and cannot meet the needs of optical measurement equipment in high-temperature environments. Summary of the Invention

[0004] To address one or more shortcomings of existing technologies, this invention provides a cooling method for spectral acquisition systems operating in high-temperature environments.

[0005] According to a cooling method for a spectral acquisition system in a high-temperature environment according to the present invention, the steps are as follows:

[0006] (1) Thermocouple equipment was used to measure the approximate temperature field distribution characteristics within a certain distance around the liquid rocket engine during test runs.

[0007] (2) Determine the safety boundary of the acquisition system based on the temperature field data of the test bench and the heat resistance of the spectral acquisition equipment itself.

[0008] (3) A combined active and passive cooling method is used to cool the wake optical measurement equipment so that the optical measurement equipment can be as close as possible to the engine wake.

[0009] (4) Using numerical simulation and experimental research, we will study and optimize the cooling scheme of the acquisition system.

[0010] (5) Adopting a modular design approach, the optimized cooling scheme that meets the requirements is finalized.

[0011] The present invention adopts the above technical solution and has the following advantages:

[0012] (1) The present invention determines the safety boundary of the spectral acquisition system and can acquire tail flame spectral data at a closer distance.

[0013] (2) The present invention adopts active and passive composite cooling technology, that is, it uses good passive heat dissipation materials and active cooling devices, which has a better heat dissipation effect.

[0014] (3) This invention utilizes numerical simulation and experimental research to optimize and iterate the entire cooling system to obtain the optimal solution that meets the requirements.

[0015] (4) The present invention adopts a modular design concept. In practical applications, the cooling module can be added or removed according to the number of optical measurement devices, and can be used flexibly. Attached Figure Description

[0016] Figure 1 Research on the technical route for cooling devices in spectral acquisition systems;

[0017] Figure 2 A preliminary measurement scheme for the temperature field around the exhaust plume of a liquid rocket;

[0018] Figure 3 Design of the overall scheme for the active and passive composite cooling module. Specific implementation methods

[0019] To make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific examples described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] 1. Temperature Field Measurement Scheme Around Liquid Rocket Engine Test Stand

[0021] like Figure 1 As shown, the thermocouples of this invention are arranged in a staggered pattern at different radii to minimize mutual interference. Simultaneously, considering the structural layout of the rocket test stand, measurements were initially conducted at three different radii: 3m, 4m, and 5m. A total of 10 thermocouples were used to measure the temperature within a 90° cone angle range. With this arrangement, after a complete test, a relatively complete temperature field distribution within a certain angle of view around the rocket will be obtained. Combined with the (imperfect) axisymmetric characteristics of the rocket's flow field, the temperature field within a certain distance around the rocket can be roughly estimated.

[0022] To address the high-temperature environment surrounding the test stand and ensure the accuracy of temperature measurements around the exhaust plume throughout the entire test (approximately 50 seconds), armored, high-speed (10Hz) thermocouples are required.

[0023] Based on relevant experimental data, the safety boundaries of various optical measurement devices are determined, and corresponding cooling measures or appropriate detection distances are then adopted accordingly.

[0024] 2. Simulation analysis and iterative optimization of the cooling device

[0025] like Figure 2 As shown, the overall design of the cooling device in this invention mainly includes two aspects of iterative optimization: iterative optimization based on simulation research and iterative optimization based on experimental research.

[0026] Once the thermal environment parameters of the test exhaust flame and the heat protection requirements (≤70℃) of the optical measurement equipment are determined, they serve as boundary conditions for subsequent design. Then, based on the temperature at the required observation distance, the overall cooling scheme and heat protection targets are designed.

[0027] Iterative optimization based on simulation research mainly involves setting up evaluation indicators, such as target temperature, coolant usage, and passive layer usage. The overall cooling effect is evaluated and screened by establishing a lumped parameter method. Then, three-dimensional numerical modeling is used to optimize the details, and the overall scheme is continuously optimized and iterated.

[0028] Iterative optimization based on experimental research mainly involves using simulation studies to optimize the cooling scheme, conducting experimental evaluations, and further optimizing the cooling scheme in conjunction with actual high-temperature scenarios. Similarly, preset evaluation indicators are used, such as target temperature, coolant usage, passive layer usage, system reliability, and passive material usage.

[0029] 3. Cooling module finalization design

[0030] This invention adopts a modular design approach, with the optical measurement transmitter and receiver forming a group, and the cooling module based on a group of optical measurement devices. The number of cooling modules can be increased or decreased according to the number of optical measurement devices, allowing for flexible application.

[0031] like Figure 3As shown, the cooling module is box-shaped, housing optical measurement equipment. The outermost layer of the cooling equipment consists of fire-resistant and heat-insulating materials (commonly silicon-aluminum heat-resistant materials, alumina fiber, carbon phenolic composite materials, silicon carbide composite materials, etc.) and an optical measurement window (high-temperature resistant glass). A cooling air curtain is installed outside the window to ensure that the window does not overheat. The second layer is the enclosure, which serves as a load-bearing, sealing, and heat insulation unit. The enclosure is planned to be made of double-layer stainless steel or single-layer stainless steel combined with tempered / high-temperature resistant glass, with an atmospheric pressure air layer in between for heat insulation. The interior of the enclosure is the active cooling zone. The third layer is a perforated air distribution plate. Distributed coolant nozzles are installed between the second and third layers. After the coolant is sprayed out, it passes through the perforated air distribution plate to form... Uniform outflow improves the temperature uniformity of the entire space. Alternative coolants include liquid nitrogen and high-pressure nitrogen (expansion pre-cooling). The internal space of the porous air distribution plate is used by the optical measurement equipment. Depending on the equipment's heat generation and the actual installation of the equipment support, local coolant compensation nozzles can be installed to address potential localized high-temperature issues. The final section is the inlet / outlet interface; the enclosure has openings for external pipes to allow coolant and cables to enter and exit, thus meeting interaction requirements. A single opening is planned to reduce the heat exchange area. Alternatively, depending on actual needs, a heat insulation layer can be installed on the outside of the pipes for water cooling. If the coolant temperature is still low after cooling the working space, it can be directly discharged from the external pipes, effectively cooling the pipes.

Claims

1. A cooling method for a spectral acquisition system designed for high-temperature environments, comprising the following steps: (1) Use thermocouple equipment to measure the approximate temperature field distribution characteristics within a certain distance around the liquid rocket engine during test firing; (2) Determine the safety boundary of the spectral acquisition system based on the temperature field data of the test bench and the heat resistance of the spectral acquisition equipment itself; (3) A combined active and passive cooling method is used to cool the wake spectrum acquisition device so that the spectrum acquisition device can be as close as possible to the engine wake. (4) Based on the safety boundary, the cooling scheme is optimized and iterated by numerical simulation and experimental research; (5) Based on the optimized cooling scheme, the cooling scheme is finalized using a modular design approach.

2. The cooling method for a spectral acquisition system in a high-temperature environment according to claim 1, characterized in that: In step (1), by using high-speed thermocouples, multi-point and multi-angle measurement methods, and the imperfect axisymmetric characteristics of the rocket flow field itself, the temperature field within a certain distance around the rocket can be estimated.

3. The cooling method for a spectral acquisition system in a high-temperature environment according to claim 1, characterized in that: In step (2), the safety boundary of the spectral acquisition system needs to be comprehensively considered in conjunction with the temperature field distribution around the test bench and the heat resistance of the spectral acquisition equipment.

4. The cooling method for a spectral acquisition system in a high-temperature environment according to claim 1, characterized in that: In step (3), a combined active and passive cooling method is adopted, and an overall cooling scheme is designed for the passive heat dissipation material and the active cooling method, so that the spectral acquisition system can acquire spectral data at close range.

5. The cooling method for a spectral acquisition system in a high-temperature environment according to claim 1, characterized in that: In step (4), the lumped parameter method is established to evaluate and screen the overall cooling scheme, and a three-dimensional numerical model is established to optimize the details of the scheme.

6. The cooling method for a spectral acquisition system in a high-temperature environment according to claim 1, characterized in that: In step (5), based on the determined overall cooling scheme, the cooling system is modularly subdivided using the modular design approach, and then the design is finalized according to the different modules.

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