Aircraft System Pipeline Working Temperature Control Method

Abstract

The present invention belongs to the technical field of integrated installation and adjustment of aircraft system pipelines, and relates to a method for controlling the working temperature of aircraft system pipelines, which is used for automatically adjusting the temperature of aircraft system pipelines under working conditions. The present invention adopts a unique design concept, and the working temperature detection method and the working temperature adjustment system work together to realize real-time detection, determination and adjustment of the temperature, realize adaptive adjustment of the working temperature, and form a closed-loop control; in the use of infrared thermal imaging technology, aiming at the characteristics of aircraft system pipeline painting, that is, using primer, topcoat and varnish to cover the pipeline surface, brightness models are constructed and analyzed simultaneously for different paint layers, rather than only measuring the outermost varnish, so as to realize accurate temperature measurement of the system pipeline.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated installation and adjustment of aircraft system pipelines, and relates to a method for controlling the working temperature of aircraft system pipelines, which is used for automatically adjusting the temperature of aircraft system pipelines under working conditions. Background Art

[0002] The multi-system pipelines designed for aircraft are used in the aircraft power system, fuel system, etc. When the working time of the system pipelines is too long, the temperatures of working liquids such as hydraulic oil and fuel will rise. Temperature is a physical quantity that measures the degree of hotness or coldness of an object and is an important thermal parameter. The measurement and control of temperature directly affect aircraft safety and flight performance. Especially for aircraft, compared with manned aircraft, there is no pilot to monitor the aircraft state and control the flight state in real time. Therefore, during the aircraft debugging process, the control of the working temperature of the system pipelines should be strengthened.

[0003] Currently, the traditional contact thermometer is used to check the temperature. There are limitations in the usage conditions, that is, the thermometer must be in direct contact with the pipeline to be measured to achieve heat exchange, and it takes a certain time for the temperature measurement to reach thermal equilibrium to obtain the temperature value, so it cannot measure in time. At the same time, only the single-point temperature can be measured each time. Due to material uniformity and manufacturing differences in different parts of the same pipeline, it is impossible to achieve temperature consistency. Therefore, the single-point temperature measurement result cannot accurately represent the highest temperature of the entire pipeline, and the result of temperature measurement is inaccurate. In addition, the above method can only achieve temperature measurement. When it is found that the measured temperature exceeds the allowable value, it is necessary to manually adjust the pressure supply test bench or change the relevant aircraft parameters, and then manually measure the temperature after adjustment. The work is cumbersome, consuming a large amount of time cost and labor cost, and the efficiency is extremely low.

[0004] Through the preliminary research on other industries and the research on advanced monitoring technologies, it is concluded that the infrared thermal imaging technology can solve the temperature measurement problem in the above problems. The specific content is that the magnitude of the thermal radiation energy of an object is directly related to the temperature of the object surface. This characteristic of thermal radiation enables people to use it for non-contact temperature measurement and thermal state analysis of objects. Infrared thermal imaging uses optoelectronic technology to detect the infrared specific band signals of the thermal radiation of an object, converts the signals into images and graphics that can be distinguished by the human vision, and can further calculate the temperature value. The infrared thermal imaging technology enables humans to overcome the visual obstacles. Thus, people can observe the temperature distribution on the object surface, which has the advantages of vividness, intuitiveness, and high accuracy display. If this technology is innovatively applied to the temperature control work of system pipelines, the temperature of the system pipelines can be accurately measured.

[0005] In addition, the measured value of the system management working temperature detected by using infrared thermal imaging technology, through parameter setting of the pressure supply test bench or the aircraft system, presetting the temperature allowable range and the automatic adjustment system, realizes real-time temperature comparison and automatic adjustment simultaneously, ensures that the temperature of the system pipeline is always within the allowable temperature range in real time, and guarantees the safety and flight performance of the aircraft. Summary of the Invention

[0006] To solve the above problems, realize the detection and automatic adjustment of the working temperature of the aircraft system pipeline, and ensure that the pipeline working temperature during aircraft commissioning and flight does not exceed the allowable temperature range, the present invention provides a method for controlling the working temperature of the aircraft system pipeline.

[0007] The technical solution of the present invention is as follows:

[0008] A method for controlling the working temperature of an aircraft system pipeline, the steps are as follows:

[0009] S1. Method for detecting the working temperature of the aircraft system pipeline

[0010] During the manufacturing stage of the aircraft system pipeline, three layers of paint will be applied to the surface of the conduit for the protection of the conduit and the distinction of uses. The first layer is a colorless primer, the second layer is a colored topcoat, and the third layer is a colorless varnish. The three layers of paint surfaces are independent of each other. Different types of paint have different radiation response degrees to heat or brightness, and at the same time, heat or brightness will gradually weaken during the process of being emitted through the three paint layers in sequence. Therefore, infrared thermal imaging needs to be carried out on the three paint layers simultaneously.

[0011] Using an infrared imaging device with mature technology, respectively receive the primer radiation brightness of the colorless primer layer, the topcoat radiation brightness of the colored topcoat layer, and the varnish radiation brightness of the colorless varnish layer; calibrate the system pipeline according to the primer radiation brightness, topcoat radiation brightness, and varnish radiation brightness, and the calibration includes the actual temperature of the system pipeline, the brightness refractive index of the surface paint layer of the system pipeline, and the equivalent brightness of the environmental radiation on this surface.

[0012] The above method for detecting the working temperature of the aircraft system pipeline is based on the analysis of the brightness refractive index of the surface paint layer of the aircraft system pipeline and the influence of the external radiation source, and the above temperature detection method is obtained to calibrate the influence of the actual temperature, refractive index of the system pipeline, and the equivalent brightness of the environmental radiation on this surface on the system pipeline, realizing high-precision measurement of the temperature distribution.

[0013] The model for constructing the paint layer radiation brightness is:

[0014]

[0015] Among them, L D is the paint layer radiation brightness, L a (T n) is the actual collected radiation luminance at temperature T n in K α is the propagation coefficient of the air medium, β θ is the refractive index of the paint layer, L b is the equivalent radiation luminance of the environmental radiation on the surface of the system pipeline.

[0016] The radiation luminances of the three-layer paint are the primer radiation luminance L Dd , the topcoat radiation luminance L Dm , and the varnish radiation luminance L Dq , and their construction models are respectively:

[0017]

[0018]

[0019]

[0020] Among them, L ad (T n ), L am (T n ), and L aq (T n ) are respectively the actual collected radiation luminances of the primer, topcoat, and varnish at temperature T n , β θd , β θm , and β θq are respectively the refractive indices of the paint layers of the primer, topcoat, and varnish, and L bd , L bm , and L bq are respectively the equivalent radiation luminances of the environmental radiation on the surfaces of the primer, topcoat, and varnish paint layers.

[0021] By establishing the construction model of the paint layer radiation luminance, the collected infrared information can be constructed into a model available for data analysis for subsequent problem adjustment.

[0022] S2. Aircraft system pipeline working temperature regulation system

[0023] Under the working state of the aircraft system pipeline, the state of over-high temperature caused by too long working time often occurs, and accurate temperature control is required. After collecting the real-time working temperature through the aircraft system pipeline working temperature detection method of S1 and establishing the paint layer radiation luminance construction model, an aircraft system pipeline working temperature regulation system is provided for precise temperature control.

[0024] The working temperature regulation system of the aircraft system pipeline mainly realizes the system control behavior by obtaining the real-time radiation luminance collected by the aircraft system pipeline working temperature detection method, outputting the result after calculation, superimposing it on the input of the system, and continuously cycling and comparing. The measured temperature W inside the system at time Tn sc and the preset working temperature W max The ratio of the upper limit value is the judgment model U(Tn):

[0025]

[0026] where U(Tn) is the system working judgment model at time Tn, W sc is the measured temperature at time Tn, W max (Tn) is the preset working temperature upper limit value at time Tn, ε is the conversion coefficient of radiation luminance to temperature, L D is the paint layer radiation luminance model.

[0027] When U(Tn) is within the range of [0, 1], the system stops temperature adjustment; when the value of U(Tn) exceeds 1, the system automatically operates for temperature adjustment until it meets the range of [0, 1], then stops temperature adjustment, and further accurately controls the working temperature of the system pipeline within the working range to achieve adaptive temperature regulation.

[0028] Among them, the specific process of temperature regulation is as follows:

[0029] When the value of U(Tn) exceeds 1, the system automatically adjusts the hydraulic pump of the hydraulic oil pump truck to reduce its speed and the driving liquid flow rate, so as to reduce the hydraulic oil thermal power and lower the working temperature. When the value of U(Tn) is less than 1, the system stops adjustment, and the hydraulic pump of the hydraulic oil pump truck resumes its original working intensity.

[0030] The beneficial effects of the present invention:

[0031] (1) The present invention adopts a unique design concept, and the working temperature detection method and the working temperature regulation system work together to realize real-time detection, determination and adjustment of temperature, achieve adaptive regulation of working temperature, and form a closed-loop control.

[0032] (2) In the working temperature detection method of the present invention, infrared thermal imaging technology is adopted, which can directly observe the temperature distribution on the surface of the system pipeline, and has the advantages of vivid, intuitive and high-accuracy display, and can obtain the actual temperature of the system pipeline in real time.

[0033] (3) In the use of infrared thermal imaging technology in the present invention, aiming at the characteristics of the aircraft system pipeline painting, that is, using primer, topcoat and varnish to cover the pipeline surface, brightness models are constructed and analyzed for different paint layers at the same time, rather than only measuring the outermost varnish, so as to achieve accurate temperature measurement of the system pipeline.

[0034] (4) The aircraft system pipeline operating temperature regulation system provided by the present invention can be used in conjunction with the pipeline operating temperature detection method. By analyzing the real-time measured temperature accurately measured according to the infrared thermal imaging technology, an innovative combination of the technical method and the analysis system is achieved.

[0035] (5) The aircraft system pipeline operating temperature regulation system provided by the present invention realizes autonomous judgment by setting a judgment algorithm model for the preset upper limit value of the operating temperature and the measured temperature, and presetting the parameter range at the same time. It no longer requires the operator to participate in the control work manually, so as to automatically and accurately control the operating temperature of the system pipeline within the working range and achieve adaptive temperature regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is the system architecture diagram of the present invention.

[0037] Figure 2 is the architecture diagram of the operating temperature detection method in the present invention.

[0038] Figure 3 is the architecture diagram of the operating temperature regulation system in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0039] The following further describes the specific embodiments of the present invention in conjunction with the drawings and technical solutions.

[0040] As Figures 1-3 shown, a method for controlling the operating temperature of an aircraft system pipeline according to the present invention comprises the following specific steps:

[0041] S1. The steps of the aircraft system pipeline operating temperature detection method are as follows:

[0042] Step S1.1, check and confirm that the spraying of three layers of paint is completed on the surface of the system conduit. The first layer is a colorless primer, the second layer is a colored topcoat, and the third layer is a colorless varnish. The three paint surfaces are independent of each other;

[0043] Step S1.2, use thermal imaging technology to perform infrared thermal imaging on the colorless primer, colored topcoat, and colorless varnish of the system pipeline simultaneously;

[0044] Step S1.3, respectively receive the primer radiation luminance of the colorless primer, the topcoat radiation luminance of the colored topcoat, and the varnish radiation luminance of the colorless varnish;

[0045] Step S1.4, calibrate the system pipeline according to the primer radiation luminance, topcoat radiation luminance, and varnish radiation luminance. The calibration includes at least one of the following: the actual temperature of the system pipeline, the brightness refractive index of the paint layer on the surface of the system pipeline, and the equivalent luminance of the environmental radiation on this surface, and construct a paint layer radiation luminance model.

[0046] In step S1.1, it is determined that two materials with known and different refractive indexes are respectively coated on the surface of the system pipeline during the catheter manufacturing stage to form a colorless primer and a colored topcoat. The two materials are independent of each other on the surface of the system pipeline, and at the same time, a colorless varnish without any coating material is reserved on the surface of the system pipeline, so as to respectively perform infrared thermal imaging on the colorless primer, the colored topcoat, and the colorless varnish of the object to be measured through an infrared thermal imaging device in step S1.2 to obtain the primer radiation luminance of the colorless primer coated with the first material, the topcoat radiation luminance of the colored topcoat coated with the second material, and the varnish radiation luminance of the colorless varnish on the outermost side of the system pipeline. In a specific implementation manner, the infrared thermal imaging device coated with the two materials simultaneously receives the radiation luminance of the three surfaces of the system pipeline, that is, simultaneously obtains the radiation luminance of the colorless primer, the colored topcoat, and the colorless varnish. In order to ensure that the test conditions of the three paint surfaces are exactly the same, it is necessary to perform infrared thermal imaging on the three paint surfaces simultaneously, that is, all three surfaces must be present in the imaging picture at the same time. Among them, the areas of the colorless primer, the colored topcoat, and the colorless varnish can be the same or different, and the specific size is subject to being able to perform infrared thermal imaging and obtain sufficient radiation luminance.

[0047] Specifically, in the embodiments of the present invention, when actually measuring the temperature of the system pipeline by an infrared thermal imaging device, the obtained radiance includes the refraction of the external radiation of the system pipeline, the path radiance of the medium, and the loss radiance of the radiance of the system pipeline. Therefore, it is often impossible to accurately obtain the brightness refractive index of the paint layer on the surface of the system pipeline. In the conventional temperature measurement process of an aircraft system pipeline provided by the embodiments of the present invention, due to the limitation of the spatial position of the aircraft system pipeline, the position of the infrared thermal imaging device is very close to the system pipeline, that is, the optical thickness of the air is very small. At this time, the influence of medium attenuation can be ignored. Since the radiance formed by different paint layer materials during infrared thermal imaging is different, three radiance values with different values can be obtained in step S1.3, namely the primer radiance, the topcoat radiance, and the third radiance. At the same time, since the first refractive index and the second refractive index of the applied primer material and topcoat material are known, the actual temperature of the system pipeline, the brightness refractive index of the paint layer on the surface of the system pipeline, and the equivalent brightness of the environmental radiation on this surface can be obtained through the radiance formed by them in the detector, that is, the actual temperature of the system pipeline, the brightness refractive index of the paint layer on the surface of the system pipeline, and the equivalent brightness of the environmental radiation on this surface are calibrated. Among them, the equivalent brightness of the environmental radiation on this surface is the equivalent brightness formed by the external high-temperature heat source at the system pipeline. After excluding the influence of the equivalent brightness of the environmental radiation on the obtained clear coat radiance and the influence of the brightness refractive index of the paint layer on the surface of the system pipeline, the accurate true temperature of the system pipeline can be obtained. And since the three paint surfaces are very close, it can be approximately considered that the equivalent brightness of the environmental radiation at the positions of the three paint surfaces is equal, that is, the equivalent brightness of the environmental radiation on the three paint surfaces is equal. Therefore, the method used in the above embodiments of the present invention is suitable for accurately measuring the actual temperature of the aircraft system pipeline, and finally the true temperature of the system pipeline can be monitored in real time.

[0048] In addition, the colorless clear coat is the part of the surface of the system pipeline except for the surface occupied by the colorless primer and the colored topcoat, or the surface on the system pipeline that does not coincide with the colorless primer and the colored topcoat. The colorless primer, the colored topcoat, and the colorless clear coat are independent of each other, and their corresponding radiance can be obtained according to step S1.4 for subsequent calculations. The radiance construction model of the paint layer is:

[0049]

[0050] Among them, L D is the radiance of the paint layer, L a (T n ) is the actually collected radiance at temperature T n , K α is the propagation coefficient of the air medium, β θ is the refractive index of the paint layer, Lb is the equivalent radiation luminance of environmental radiation on the surface of the system pipeline.

[0051] The radiation luminances of the three-layer paint film are the radiation luminance L of the primer Dd , the radiation luminance L of the topcoat Dm , and the radiation luminance L of the varnish Dq , and the constructed models are respectively:

[0052]

[0053]

[0054]

[0055] Among them, L ad (T n ), L am (T n ), and L aq (T n ) are the actually collected radiation luminances of the primer, topcoat, and varnish at temperature T n respectively, β θd , β θm , and β θq are the refractive indices of the primer, topcoat, and varnish respectively, and L bd , L bm , and L bq are the equivalent radiation luminances of environmental radiation on the surfaces of the primer, topcoat, and varnish paint films respectively.

[0056] Taking the hydraulic system pipeline of a certain type of aircraft as an example, through the construction of the radiation luminances of the three-layer paint film, the collected radiation luminance L of the primer Dd is 0.2 W / m 2 ·sr; the radiation luminance L of the paint Dm is 1.1 W / m 2 ·sr; the radiation luminance L of the varnish Dq is 1.9 W / m 2 ·sr.

[0057] S2. Steps of the aircraft system pipeline working temperature regulation system are as follows:

[0058] Step S2.1, obtain the collected real-time radiation luminance through the radiation luminance of the paint film constructed in step S1.4 of the present invention;

[0059] Step S2.2, after operating on the collected real-time radiation luminance, the ratio of the measured temperature W sc inside the system at time Tn to the preset upper limit value of the working temperature W max is the judgment model U(Tn):

[0060]

[0061] Among them, U(Tn) is the system working judgment model at time Tn, and W sc is the measured temperature at time Tn, and W max (Tn) is the preset upper limit value of the working temperature at time Tn, ε is the conversion coefficient of radiant luminance to temperature, and L D is the paint layer radiant luminance model.

[0062] When the measured temperature exceeds the preset upper limit value of the working temperature, an adjustment instruction is sent to the aircraft or the ground test bench to control the temperature;

[0063] Step S2.3, in view of the real-time change of the working temperature of the system pipeline and the need for real-time adjustment, the range value of the judgment model U(Tn) is automatically determined in the working temperature adjustment system. When U(Tn) is within the range of [0, 1], the system stops temperature adjustment; when the value of U(Tn) exceeds 1, the system runs automatically until it meets the range of [0, 1], and then stops temperature adjustment, thereby accurately controlling the working temperature of the system pipeline within the working range and realizing adaptive temperature adjustment.

[0064] Taking a certain type of aircraft as an example, when the value of U(Tn) is 1.3, the system automatically adjusts the hydraulic pump of the hydraulic oil pump truck to reduce its rotational speed and the driving liquid flow rate, so as to reduce the thermal power of the hydraulic oil and lower the working temperature. When the value of U(Tn) is less than 1, the system stops adjustment, and the hydraulic pump of the hydraulic oil pump truck resumes its original working intensity.

[0065] If the value of U(Tn) is 0.8, which is less than 1, the system does not make adjustments, and the hydraulic pump of the hydraulic oil pump truck operates at the normal working intensity.

Claims

1. A method for controlling the working temperature of an aircraft system pipeline, characterized in that, The steps are as follows: S1. Aircraft system pipeline working temperature detection method During the manufacturing stage of the aircraft system pipeline, three layers of paint are applied to the surface of the conduit for protection and use differentiation. The first layer is a colorless primer, the second layer is a colored topcoat, and the third layer is a colorless varnish. The three paint layers are independent of each other. Different types of paint have different radiation response degrees to heat or brightness, and at the same time, heat or brightness will gradually weaken during the process of being emitted through the three paint layers in sequence. Therefore, infrared thermal imaging needs to be carried out on the three paint layers simultaneously; Use infrared imaging equipment to respectively receive the primer radiation brightness of the colorless primer layer, the topcoat radiation brightness of the colored topcoat layer, and the varnish radiation brightness of the colorless varnish layer; Calibrate the system pipeline according to the primer radiation brightness, topcoat radiation brightness, and varnish radiation brightness. The calibration includes the actual temperature of the system pipeline, the brightness refractive index of the paint layer on the surface of the system pipeline, and the equivalent brightness of the environmental radiation on this surface; The model for constructing the paint layer radiation brightness is: Among them, L D is the radiation luminance of the paint layer, L a (T n ) is the actually collected radiation luminance at temperature T n , K α is the propagation coefficient of the air medium, β θ is the refractive index of the paint layer, L b is the equivalent radiation luminance of the environmental radiation on the surface of the system pipeline; Through the establishment of the model for constructing the paint layer radiation brightness, the collected infrared information is constructed into a model available for data analysis for subsequent temperature adjustment; S2. Aircraft system pipeline working temperature adjustment system After obtaining the real-time radiance through S1, the output is calculated and then superimposed on the input of the system. Through continuous cyclic comparison, the behavior of system control is achieved. The measured temperature W within the system at time Tn sc and the preset operating temperature W max The ratio of the upper limit value is the judgment model U(Tn): Among them, U(Tn) is the system working judgment model at time Tn, and W sc is the measured temperature at time Tn, and W max (Tn) is the preset upper limit value of the working temperature at time Tn, ε is the conversion coefficient of radiation luminance to temperature, and L D is the radiation luminance model of the paint layer; When U(Tn) is within the range of [0, 1], the system stops temperature adjustment; when the value of U(Tn) exceeds 1, the system automatically operates for temperature adjustment until it meets the range of [0, 1], and then stops temperature adjustment, thereby accurately controlling the working temperature of the system pipeline within the working range and achieving adaptive temperature adjustment.

2. The method for controlling the working temperature of an aircraft system pipeline according to claim 1, characterized in that, The radiant luminance of the three-layer paint layer is the primer radiant luminance L Dd , the topcoat radiant luminance L Dm , and the varnish radiant luminance L Dq . Their construction models are respectively as follows: Among them, L ad (T n )、L am (T n ) and L aq (T n ) are the actually collected radiance of the primer, topcoat and varnish at temperature T n respectively, β θd , β θm and β θq are the refractive indices of the primer, topcoat and varnish layers respectively, L bd , L bm and L bq are the equivalent radiance of the ambient radiation on the surfaces of the primer, topcoat and varnish layers respectively.

3. A method for controlling the working temperature of an aircraft system pipeline according to claim 1, characterized in that, Among them, The specific process of temperature adjustment is as follows: when the value of U(Tn) exceeds 1, the system automatically adjusts the hydraulic pump of the hydraulic oil pump truck to reduce its speed, reduce the driving liquid flow rate, reduce the thermal power of the hydraulic oil, and lower the working temperature; When the value of U(Tn) is less than 1, the system stops adjustment, and the hydraulic pump of the hydraulic oil pump truck resumes its original working intensity.

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