Kerosene ice crystal testing device for engine, kerosene filling system and kerosene filling method

Abstract

The invention discloses a kerosene ice crystal testing device for an engine, a kerosene filling system and a kerosene filling method, and solves the problem that kerosene supply of the engine is interrupted due to relatively large flow resistance of kerosene caused by narrowing of a runner of a kerosene conveying pipeline due to freezing. The kerosene ice crystal testing device specifically comprises a testing cavity, a kerosene inlet, an observation window, a kerosene outlet, a filter screen, an illuminating lamp and an image acquisition module, wherein the kerosene inlet and the observation window are formed in the side wall of the testing cavity; the kerosene outlet is formed in the bottom of the testing cavity; the test unit is electrically connected with the illuminating lamp and the image acquisition module respectively; the kerosene inlet and the observation window correspond to the position of the filter screen; the illuminating lamp and the action end of the image acquisition module correspond to the observation window; and the test unit is used for controlling the illuminating lamp and the image acquisition module and analyzing the kerosene icing state according to the filter screen picture acquired by the image acquisition module so as to complete kerosene ice crystal test.

Description

Technical Field

[0001] This invention relates to a kerosene filling system and method, specifically to a kerosene ice crystal testing device, kerosene filling system and method for engines. Background Technology

[0002] In the field of space launch, liquid oxygen-kerosene launch vehicles have become the core launch vehicle for various spacecraft launch missions due to their superior thrust performance and good economy.

[0003] In recent years, with the continuous increase in the frequency and density of space launch missions, more stringent requirements have been placed on the overall operational efficiency of rocket launch systems. Among these, improving the fueling efficiency of the rocket engine kerosene refueling system is particularly crucial. As a core component of the liquid oxygen-kerosene launch vehicle propulsion system, the quality and efficiency of aerospace kerosene directly determine the progress and reliability of launch missions, making it a vital link in ensuring a successful rocket launch.

[0004] Currently, most space launch sites use liquid nitrogen supercooler circulation technology for kerosene refueling of engines. This technology is characterized by stable cooling efficiency and wide adaptability, and is widely used in existing launch missions. However, during actual kerosene refueling, due to the significant temperature difference between liquid nitrogen and kerosene, icing is highly likely to occur during the heat exchange process. Icing narrows the kerosene delivery pipeline, creating significant flow resistance. This not only severely reduces refueling efficiency and affects launch mission scheduling, but can also lead to kerosene supply interruptions, resulting in launch malfunctions and posing a serious threat to the safety and reliability of space launch missions. Therefore, solving the icing problem during kerosene refueling using the existing liquid nitrogen supercooler circulation technology and improving refueling efficiency and stability has become an urgent need for the optimization and upgrading of current space launch systems. Summary of the Invention

[0005] To address the technical problem that ice formation is prone to occur during the heat exchange process of existing engine kerosene refueling, which narrows the kerosene delivery pipeline and creates significant flow resistance, severely reducing refueling efficiency, affecting launch mission scheduling, and potentially causing engine kerosene supply interruption, leading to launch failure and posing a serious threat to the safety and reliability of space launch missions, this invention provides a kerosene ice crystal testing device, kerosene refueling system, and method for engines.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A kerosene ice crystal testing device for engines, characterized by: It includes a test chamber, a kerosene inlet and an observation window located on the side wall of the test chamber, a kerosene outlet located at the bottom of the test chamber, a filter screen installed inside the test chamber, a lighting lamp and an image acquisition module located on the observation window, and a test unit electrically connected to the lighting lamp and the image acquisition module respectively. The kerosene inlet and the observation window are both located corresponding to the filter screen. The active ends of the lighting lamp and the image acquisition module are both corresponding to the observation window. The lighting lamp is used to illuminate the filter screen, and the image acquisition module is used to acquire images of the filter screen and send them to the test unit. The test unit is used to control the lighting and image acquisition module, and analyzes the kerosene freezing state based on the filter images acquired by the image acquisition module to complete the kerosene ice crystal test.

[0007] Furthermore, an installation bucket is provided on the outer wall of the test chamber at the observation window; One end of the mounting bucket opening is fixed to the outer wall of the test chamber and is positioned directly opposite the observation window, while the other end is suspended horizontally; the inside of the mounting bucket is in a vacuum state, and a mounting plate is fixed to its inner wall. The lighting lamp and image acquisition module are fixedly mounted on the mounting plate, and the connection between the two and the test unit is run through the bottom of the mounting barrel.

[0008] Furthermore, the test chamber includes a chamber body and a test chamber cover disposed on top of the chamber body; The test chamber cover is connected to the flange of the chamber body; The test chamber cover is equipped with a handle.

[0009] Furthermore, the filter screen is cylindrical, with one end fixedly installed on the inner wall of the bottom of the test chamber cover, and the other end extending downward into the chamber body and below the position of the kerosene inlet and the observation window. Multiple layers of mesh are evenly arranged inside from top to bottom.

[0010] A kerosene filling system for engines, characterized by: This includes a kerosene supply container, a heat exchanger, and the aforementioned kerosene ice crystal testing device for engines. The first outlet of the kerosene supply container is connected to the hot end of the heat exchanger via a first kerosene pipe and a second kerosene pipe that are interconnected. A third kerosene pipe is connected to the second outlet of the kerosene supply container and is used to connect to the engine to be refueled. A fourth kerosene pipe is connected between the third kerosene pipe and the second kerosene pipe. The connection point between the fourth kerosene pipe and the third kerosene pipe is located close to the engine to be refueled, and the connection point between the fourth kerosene pipe and the second kerosene pipe is located at the connection point of the first kerosene pipe and the second kerosene pipe. Remote control valves are respectively installed on the first kerosene pipe and the fourth kerosene pipe. The cold end of the heat exchanger is connected to the inlet end of the kerosene supply container via a fifth kerosene pipeline; The kerosene ice crystal testing device is installed on the fifth kerosene pipeline. The kerosene inlet and kerosene outlet of its testing chamber are connected to the cold end of the heat exchanger and the oil inlet of the kerosene supply container through the fifth kerosene pipeline, respectively.

[0011] Furthermore, a pump and a flow meter are installed on the second kerosene pipeline.

[0012] Furthermore, a remote-controlled valve is installed on the fifth kerosene pipeline located between the kerosene ice crystal testing device and the kerosene supply container at the inlet end.

[0013] A kerosene filling method for an engine, employing the aforementioned kerosene filling system for an engine, is characterized by including the following steps: Step 1: Add kerosene to the kerosene supply container and open the remote control valve on the first kerosene pipeline. The kerosene in the kerosene supply container passes through the first kerosene pipeline, the second kerosene pipeline, the heat exchanger, the kerosene ice crystal testing device, and the fifth kerosene pipeline in sequence before entering the kerosene supply container, forming a small circulation. Through this small circulation, the temperature of the kerosene in the kerosene supply container drops to the preset temperature. At the same time, the lighting is turned on to illuminate the filter screen inside the test chamber, and the image acquisition module continuously acquires images of the filter screen and sends them to the test unit. Step 2: During the small loop, the test unit calculates the icing degree index of the current filter screen based on the received image. If the current icing degree index is greater than the preset value, the remote control valve on the first kerosene pipeline is closed, the filter screen is de-iced, and a heat exchanger with a different heat exchange efficiency is replaced. Then, the process returns to Step 1 until the icing degree index of the filter screen is less than or equal to the preset value within a preset time. The current kerosene temperature is then obtained and recorded as the critical temperature. Step 3: Close the remote control valve on the first kerosene pipeline and open the remote control valve on the fourth kerosene pipeline. The kerosene in the kerosene supply container passes through the third kerosene pipeline, the fourth kerosene pipeline, the second kerosene pipeline, the heat exchanger, the kerosene ice crystal testing device, and the fifth kerosene pipeline in sequence before entering the kerosene supply container, forming a large circulation. Through this large circulation, the temperature of the kerosene in the third kerosene pipeline is reduced to the critical temperature. Step 4: Close the remote control valve on the fourth kerosene pipeline. The kerosene in the kerosene supply container is then supplied to the engine to be filled via the third kerosene pipeline at the preset temperature.

[0014] Further, in step 2, the method by which the testing unit calculates the icing degree index on the current filter screen based on the received image includes the following steps: Step A: Preprocess the received images and obtain the regions of interest (ROIs) of the images; Step B: Extract features from the region of interest in the image to obtain the corresponding feature values; the feature values ​​include texture roughness, average gray value, feature point abundance value, and spectral energy. Step C: Fuse the extracted feature values ​​to obtain the fused feature value, which is denoted as the icing degree index.

[0015] Further, step 1 specifically involves adding kerosene to the kerosene supply container, opening the remote control valves on the first kerosene pipeline, the pump, and the fifth kerosene pipeline. The kerosene in the kerosene supply container flows sequentially through the first kerosene pipeline, the second kerosene pipeline, the heat exchanger, the kerosene ice crystal testing device, and the fifth kerosene pipeline before entering the kerosene supply container again, forming a small circulation. Through this small circulation, the temperature of the kerosene in the kerosene supply container drops to a preset temperature. Simultaneously, the lighting is activated to illuminate the filter screen inside the test chamber, and images of the filter screen are continuously acquired by the image acquisition module and sent to the test unit. Step 4 specifically involves closing the remote control valves on the pump and the fourth kerosene pipeline, and then supplying the kerosene in the kerosene supply container to the engine to be filled via the third kerosene pipeline at a preset temperature.

[0016] The beneficial effects of this invention are: 1. The kerosene ice crystal testing device for engines provided by this invention sets up a test chamber and installs a filter screen inside the test chamber to filter the flowing kerosene. If the ice crystal particles in the kerosene are too large, they will inevitably hang on the filter screen. The filter screen image is captured by an image acquisition module, and the size of the ice crystal particles is judged in real time based on the image. This serves as feedback for replacing heat exchangers with different heat exchange efficiencies, thereby preventing the kerosene ice crystals from clogging the pipes, improving the kerosene filling efficiency, ensuring a continuous supply of kerosene to the engine, reducing launch failures, and greatly improving the safety and reliability of aerospace launch missions. This kerosene ice crystal testing device achieves visualized testing, and the test results are more accurate.

[0017] 2. The kerosene filling system and method for engines provided by this invention first reduces the temperature of the kerosene in the kerosene supply container through a small circulation loop. At the same time, an ice crystal test is conducted using a kerosene ice crystal testing device. This allows for the replacement of a heat exchanger with appropriate heat exchange efficiency based on the specific composition of the kerosene, preventing excessive ice crystals from clogging the pipes. Before starting the engine to be filled, the temperature of the third kerosene pipe is reduced through a large circulation loop to prevent the kerosene flowing through the third kerosene pipe from being reheated, which could affect the normal starting of the engine and ensure the stability of engine operation.

[0018] 3. The kerosene filling system and method for engines provided by the present invention can start the kerosene circulation and heat exchange one day in advance through a small circulation to reduce its temperature to a critical temperature that does not clog the pipes. Then, just before the engine starts, a large circulation is used to reduce the temperature of the third kerosene pipe directly connected to the engine, which greatly improves the filling quality and efficiency of the engine. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an embodiment of the kerosene ice crystal testing device for engines according to the present invention; Figure 2 This is a cross-sectional view of the test chamber and filter screen in an embodiment of the present invention; Figure 3 This is a schematic diagram of an embodiment of a kerosene filling system for an engine according to the present invention.

[0020] The attached figures are labeled as follows: 1. Test chamber; 11. Kerosene inlet; 12. Observation window; 13. Kerosene outlet; 14. Test chamber cover; 15. Handle; 16. Chamber body; 2. Filter screen; 3. Illumination lamp; 4. Image acquisition module; 5. Test unit; 6. Mounting bucket; 61. Mounting plate; 7. Kerosene supply container; 71. First oil outlet; 72. Second oil outlet; 73. Oil inlet; 8. Heat exchanger; 9. Engine to be filled; 91. First kerosene pipeline; 92. Second kerosene pipeline; 93. Third kerosene pipeline; 94. Fourth kerosene pipeline; 95. Fifth kerosene pipeline; 10. Pump; 100. Kerosene ice crystal testing device. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides a kerosene ice crystal testing device for engines, such as... Figure 1 As shown, the kerosene ice crystal testing device includes a test chamber 1, a kerosene inlet 11 and an observation window 12 disposed on the side wall of the test chamber 1, a kerosene outlet 13 disposed at the bottom of the test chamber 1, a filter screen 2 installed inside the test chamber 1, an illumination lamp 3 and an image acquisition module 4 disposed on the observation window 12, and a test unit 5 electrically connected to the illumination lamp 3 and the image acquisition module 4 respectively.

[0023] The test chamber 1 includes a chamber body 16 and a test chamber cover 14 disposed on the top of the chamber body 16; the test chamber cover 14 is flange-connected to the chamber body 16; two handles 15 are arranged side by side on the test chamber cover 14. An installation bucket 6 is provided on the outer wall of the chamber body 16 at the observation window 12; one end of the installation bucket 6 is open and the other end has a bottom; one open end of the installation bucket 6 is fixedly connected to the outer wall of the chamber body 16 and is positioned directly opposite the observation window 12, while the other end is horizontally suspended, and its interior is in a vacuum state; an installation plate 61 is fixedly connected inside the installation bucket 6.

[0024] The filter screen 2 is cylindrical, with one end fixedly installed on the inner wall of the bottom of the test chamber cover 14, and the other end extending downward into the chamber body 16, below the position of the kerosene inlet 11 and the observation window 12. Since the positions of the kerosene inlet 11 and the observation window 12 correspond to those of the filter screen 2, all kerosene entering the chamber body 16 from the kerosene inlet 11 will be filtered by the filter screen 2. If ice forms, ice crystals will hang on the filter screen 2; the state of ice crystal accumulation can be observed through the observation window 12.

[0025] The active end of the lighting lamp 3 corresponds to the observation window 12 and is used to illuminate the filter screen 2; the active end of the image acquisition module 4 corresponds to the observation window 12 and is used to acquire images of the filter screen 2 and send them to the test unit 5; the lighting lamp 3 and the image acquisition module 4 are fixedly installed on the mounting plate 61, and the connection between the two and the test unit 5 is run through the bottom of the mounting bucket 6.

[0026] In this embodiment, the image acquisition module 4 can be a camera device. The camera device can record key information such as the morphological changes and enrichment rate of kerosene ice crystals in real time. Using this key information, the structure of the filter screen 2 can be optimized to more effectively prolong the kerosene ice crystal enrichment process, significantly improve the system's ability to resist ice crystal condensation, and ensure the safe and stable operation of the kerosene filling system under various working conditions. The inside of the installation tank 6 is vacuum-sealed to prevent water vapor from condensing at the camera end of the camera device for image acquisition.

[0027] Test unit 5 is used to control the lighting lamp 3 and the image acquisition module 4, and analyzes the kerosene freezing state based on the image of the filter screen 2 acquired by the image acquisition module 4, so as to complete the kerosene ice crystal test.

[0028] This invention provides a kerosene filling system for an engine, such as... Figure 3 As shown, the kerosene filling system includes a kerosene supply container 7, a heat exchanger 8, and the aforementioned kerosene ice crystal testing device 100 for the engine. The first oil outlet 71 of the kerosene supply container 7 is connected to the hot end of the heat exchanger 8 via a first kerosene pipe 91 and a second kerosene pipe 92, which are interconnected. A third kerosene pipe 93 is connected to the second oil outlet 72 of the kerosene supply container 7. The third kerosene pipe 93 is a DN300mm pipe with a length of 30m and is used to connect to the engine 9 to be filled. A fourth kerosene pipe 94 is connected between the third kerosene pipe 93 and the second kerosene pipe 92. The connection point between the fourth kerosene pipe 94 and the third kerosene pipe 93 is located close to the engine 9 to be filled, and the connection point between the fourth kerosene pipe 94 and the second kerosene pipe 92 is located at the connection point of the first kerosene pipe 91 and the second kerosene pipe 92. Remote control valves are respectively installed on the first kerosene pipe 91 and the fourth kerosene pipe 94. A pump 10 and a flow meter are installed on the second kerosene pipe 92.

[0029] The cold end of the heat exchanger 8 is connected to the oil inlet 73 of the kerosene supply container 7 via the fifth kerosene pipeline 95; a remote control valve is provided on the fifth kerosene pipeline 95 located between the kerosene ice crystal testing device 100 and the oil inlet 73 of the kerosene supply container 7.

[0030] The kerosene ice crystal testing device 100 is installed on the fifth kerosene pipeline 95. The kerosene inlet 11 and kerosene outlet 13 of its testing chamber 1 are connected to the cold end of the heat exchanger 8 and the oil inlet 73 of the kerosene supply container 7 through the fifth kerosene pipeline 95, respectively.

[0031] The aforementioned kerosene filling system forms a small circulation between the kerosene supply container 7, the first kerosene pipeline 91, the second kerosene pipeline 92, the heat exchanger 8, and the fifth kerosene pipeline 95, and a large circulation between the kerosene supply container 7, the third kerosene pipeline 93, the fourth kerosene pipeline 94, the second kerosene pipeline 92, the heat exchanger 8, and the fifth kerosene pipeline 95. The small circulation can heat the kerosene in the kerosene supply container 7 to the critical state of kerosene freezing one day in advance, and then reduce the temperature of the third kerosene pipeline 93 through the large circulation.

[0032] Because the third kerosene pipe 93 is too long and usually has a high temperature, if kerosene is directly added from the kerosene supply container 7 to the engine 9 to be filled, the heat loss of the third kerosene pipe 93 will be large, which will affect the heat exchange efficiency. Therefore, a fourth kerosene pipe 94 was designed to achieve a large circulation. The large circulation can be carried out before the engine 9 to be filled is about to start, so as to reduce the temperature of the third kerosene pipe 93 and prevent the kerosene from being heated when passing through the third kerosene pipe 93, which would affect the normal start of the engine 9 to be filled.

[0033] The method for adding kerosene to the engine 9 to be filled using the above-mentioned kerosene filling system specifically includes the following steps: Step 1: Add kerosene to the kerosene supply container 7, open the remote control valve on the first kerosene pipeline 91, the pump 10, and the remote control valve on the fifth kerosene pipeline 95. The kerosene in the kerosene supply container 7 passes through the first kerosene pipeline 91, the second kerosene pipeline 92, the heat exchanger 8, the kerosene ice crystal testing device 100, and the fifth kerosene pipeline 95 in sequence, and then enters the kerosene supply container 7 to form a small circulation. Through this small circulation, the temperature of the kerosene in the kerosene supply container 7 drops to the preset temperature. At the same time, the lighting lamp 3 is turned on to illuminate the filter screen 2 inside the test chamber 1, and the image acquisition module 4 continuously acquires images of the filter screen 2 and sends them to the test unit 5; Step 2: During the small loop, the test unit 5 calculates the IDI (Index of Icing) on ​​the current filter screen 2 based on the received image. If the IDI on the current filter screen 2 is greater than the preset value (0.8), the remote control valve on the first kerosene pipeline 91 is closed, the filter screen 2 is de-iced, and the heat exchanger 8 with a different heat exchange efficiency is replaced. The process returns to step 1 until the IDI on the filter screen 2 is less than or equal to 0.8 within a preset time (usually one day). The current kerosene temperature is then obtained and recorded as the critical temperature.

[0034] The method by which the above-mentioned test unit 5 calculates the icing degree index on the current filter 2 based on the received image includes the following steps: Step A: Preprocess the received images and obtain the regions of interest (ROIs) of the images; Step B: Extract features from the region of interest in the image and obtain the corresponding feature values; these feature values ​​include texture roughness, average gray value, feature abundance value, and spectral energy. For texture roughness extraction: Method: Texture analysis, a technique in image processing, is used to calculate features of the region of interest in the image.

[0035] Output: A texture feature value representing the surface roughness is obtained. The more ice crystals there are, the greater the texture roughness.

[0036] For the extraction of feature point abundance values: Method: A feature point detection algorithm is applied to identify and count key points (such as corners and spots) in the region of interest of an image.

[0037] Output: A feature point abundance value reflecting the number of ice crystal particles is obtained. The more ice crystals there are, the higher the feature point abundance value.

[0038] For the extraction of spectral energy: Method: Perform frequency domain transformation on the region of interest in the image and analyze the proportion of its high-frequency energy in the total energy.

[0039] Output: A spectral energy that is sensitive to early, trace amounts of ice crystals; the more ice crystals, the greater the spectral energy.

[0040] Step C: Fuse the extracted feature values ​​to obtain the fused feature value, which is denoted as the IDI (Ice Degree Index).

[0041] Step 3: Close the remote control valve on the first kerosene pipeline 91 and open the remote control valve on the fourth kerosene pipeline 94. The kerosene in the kerosene supply container 7 passes through the third kerosene pipeline 93, the fourth kerosene pipeline 94, the second kerosene pipeline 92, the heat exchanger 8, the kerosene ice crystal testing device 100, and the fifth kerosene pipeline 95 in sequence before entering the kerosene supply container 7, forming a large circulation. Through this large circulation, the temperature of the kerosene in the third kerosene pipeline 93 is reduced to the critical temperature. Step 4: Close the remote control valves on pump 10 and the fourth kerosene pipeline 94. The kerosene in the kerosene supply container 7 is supplied to the engine 9 to be filled via the third kerosene pipeline 93 at a preset temperature.

[0042] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A kerosene ice crystal testing device for engines, characterized in that: The test chamber (1) includes a kerosene inlet (11) and an observation window (12) on the side wall of the test chamber (1), a kerosene outlet (13) at the bottom of the test chamber (1), a filter screen (2) installed inside the test chamber (1), a lighting lamp (3) and an image acquisition module (4) installed on the observation window (12), and a test unit (5) electrically connected to the lighting lamp (3) and the image acquisition module (4) respectively. The kerosene inlet (11) and the observation window (12) are both located corresponding to the filter screen (2); The active ends of the lighting lamp (3) and the image acquisition module (4) are both corresponding to the observation window (12). The lighting lamp (3) is used to illuminate the filter screen (2), and the image acquisition module (4) is used to acquire the image of the filter screen (2) and send it to the test unit (5). The test unit (5) is used to control the lighting lamp (3) and the image acquisition module (4), and analyzes the kerosene freezing state based on the filter screen (2) image acquired by the image acquisition module (4) to complete the kerosene ice crystal test.

2. The kerosene ice crystal testing device for engines according to claim 1, characterized in that: An installation bucket (6) is provided on the outer wall of the test chamber (1) at the observation window (12); The installation bucket (6) has one end fixed to the outer wall of the test chamber (1) and is positioned directly opposite the observation window (12), while the other end is suspended horizontally. The inside of the installation bucket (6) is in a vacuum state, and an installation plate (61) is fixed to its inner wall. The lighting lamp (3) and the image acquisition module (4) are fixedly installed on the mounting plate (61), and the connection between the two and the test unit (5) is passed through the bottom of the mounting bucket (6).

3. The kerosene ice crystal testing device for engines according to claim 1 or 2, characterized in that: The test chamber (1) includes a chamber body (16) and a test chamber cover (14) disposed on the top of the chamber body (16). The test chamber cover (14) is flange-connected to the chamber body (16); The test chamber cover (14) is provided with a handle (15).

4. The kerosene ice crystal testing device for engines according to claim 3, characterized in that: The filter screen (2) is cylindrical, with one end fixedly installed on the bottom inner wall of the test chamber cover (14), and the other end extending downward into the chamber body (16) and below the kerosene inlet (11) and the observation window (12). Multiple layers of mesh are evenly arranged inside from top to bottom.

5. A kerosene filling system for an engine, characterized in that: Includes a kerosene supply container (7), a heat exchanger (8), and a kerosene ice crystal testing device (100) for an engine as described in any one of claims 1-4. The first oil outlet (71) of the kerosene supply container (7) is connected to the hot end of the heat exchanger (8) through the first kerosene pipe (91) and the second kerosene pipe (92) that are interconnected. A third kerosene pipe (93) is connected to the second oil outlet (72) of the kerosene supply container (7). The third kerosene pipe (93) is used to connect to the engine (9) to be refueled. A fourth kerosene pipe (94) is connected between the third kerosene pipe (93) and the second kerosene pipe (92). The connection point between the fourth kerosene pipe (94) and the third kerosene pipe (93) is located close to the engine (9) to be refueled. The connection point between the fourth kerosene pipe (94) and the second kerosene pipe (92) is located at the connection point of the first kerosene pipe (91) and the second kerosene pipe (92). Remote control valves are respectively provided on the first kerosene pipe (91) and the fourth kerosene pipe (94). The cold end of the heat exchanger (8) is connected to the oil inlet (73) of the kerosene supply container (7) via the fifth kerosene pipeline (95); The kerosene ice crystal testing device (100) is installed on the fifth kerosene pipeline (95). The kerosene inlet (11) and kerosene outlet (13) of its testing chamber (1) are connected to the cold end of the heat exchanger (8) and the oil inlet (73) of the kerosene supply container (7) through the fifth kerosene pipeline (95), respectively.

6. The kerosene filling system for an engine according to claim 5, characterized in that: The second kerosene pipeline (92) is equipped with a pump (10) and a flow meter.

7. The kerosene filling system for an engine according to claim 5 or 6, characterized in that: A remote control valve is provided on the fifth kerosene pipeline (95) located between the kerosene ice crystal testing device (100) and the inlet end (73) of the kerosene supply container (7).

8. A method for filling an engine with kerosene, employing the kerosene filling system for an engine as described in any one of claims 5-7, characterized in that, Includes the following steps: Step 1: Add kerosene to the kerosene supply container (7), open the remote control valve on the first kerosene pipeline (91), and the kerosene in the kerosene supply container (7) passes through the first kerosene pipeline (91), the second kerosene pipeline (92), the heat exchanger (8), the kerosene ice crystal testing device (100), and the fifth kerosene pipeline (95) in sequence, and then enters the kerosene supply container (7) to form a small circulation. Through this small circulation, the temperature of the kerosene in the kerosene supply container (7) drops to the preset temperature. At the same time, the lighting lamp (3) is turned on to illuminate the filter screen (2) inside the test chamber (1), and the image acquisition module (4) continuously acquires images of the filter screen (2) and sends them to the test unit (5). Step 2: During the small loop process, the test unit (5) calculates the icing degree index on the current filter screen (2) based on the received image. If the current icing degree index is greater than the preset value, the remote control valve on the first kerosene pipeline (91) is closed, the filter screen (2) is de-iced, and a heat exchanger (8) with different heat exchange efficiencies is replaced. Then, the process returns to step 1 until the icing degree index of the filter screen (2) is less than or equal to the preset value within the preset time. The current kerosene temperature is obtained and recorded as the critical temperature. Step 3: Close the remote control valve on the first kerosene pipeline (91) and open the remote control valve on the fourth kerosene pipeline (94). The kerosene in the kerosene supply container (7) passes through the third kerosene pipeline (93), the fourth kerosene pipeline (94), the second kerosene pipeline (92), the heat exchanger (8), the kerosene ice crystal testing device (100), and the fifth kerosene pipeline (95) in sequence, and then enters the kerosene supply container (7) to form a large circulation. Through this large circulation, the temperature of the kerosene in the third kerosene pipeline (93) is reduced to the critical temperature. Step 4: Close the remote control valve on the fourth kerosene pipeline (94), and the kerosene in the kerosene supply container (7) is supplied to the engine (9) to be filled with kerosene at the preset temperature via the third kerosene pipeline (93).

9. The kerosene filling method for an engine according to claim 8, characterized in that, In step 2, the method by which the test unit (5) calculates the icing degree index on the current filter (2) based on the received image includes the following steps: Step A: Preprocess the received images and obtain the regions of interest (ROIs) of the images; Step B: Extract features from the region of interest in the image to obtain the corresponding feature values; the feature values ​​include texture roughness, average gray value, feature point abundance value, and spectral energy. Step C: Fuse the extracted feature values ​​to obtain the fused feature value, which is denoted as the icing degree index.

10. The kerosene filling method for an engine according to claim 9, characterized in that, Step 1 specifically involves adding kerosene to the kerosene supply container (7), opening the remote control valve on the first kerosene pipeline (91), the pump (10), and the remote control valve on the fifth kerosene pipeline (95). The kerosene in the kerosene supply container (7) passes sequentially through the first kerosene pipeline (91), the second kerosene pipeline (92), the heat exchanger (8), the kerosene ice crystal testing device (100), and the fifth kerosene pipeline (95) before entering the kerosene supply container (7) again, forming a small circulation. Through this small circulation, the temperature of the kerosene in the kerosene supply container (7) drops to the preset temperature. At the same time, the lighting lamp (3) is turned on to illuminate the filter screen (2) in the test chamber (1), and the image acquisition module (4) continuously acquires images of the filter screen (2) and sends them to the test unit (5). Step 4 specifically involves closing the remote control valves on the pump (10) and the fourth kerosene pipeline (94), and then adding kerosene from the kerosene supply container (7) to the engine (9) to be filled via the third kerosene pipeline (93) at a preset temperature.

Images