A wall temperature measurement correction method for contact temperature sensor

Abstract

The present application relates to a method for correcting the temperature measurement of a contact temperature sensor wall surface, which takes into account the actual situation that there is heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall surface, convection heat exchange between the sensing part and the fluid on one side of the temperature measuring wall surface, radiation heat exchange between the sensing part and the surrounding environment, and heat conduction between the sensing part and the leads of the contact temperature sensor, and constructs a convection heat transfer equation between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall surface, a radiation heat transfer equation between the sensing part and the surrounding environment, a heat conduction equation between the sensing part and the leads, and a heat conduction equation between the sensing part and the temperature measuring wall surface, and then establishes a thermal balance equation for the sensing part of the contact temperature sensor, corrects the reading of the contact temperature sensor, and obtains the temperature of the temperature measuring wall surface with high accuracy.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft engine contact temperature sensor wall surface, and specifically relates to a contact temperature sensor wall surface temperature measurement correction method. Background Art

[0002] Aircraft engine testing involves measuring the temperature of the aircraft engine wall. Currently, thermocouples and optical fibers are mostly used for measurement. Thermocouples are contact temperature sensors, which are usually installed directly on the temperature measuring wall of the aircraft engine for temperature measurement. The thermocouple and optical fiber readings are used as the temperature of the temperature measuring wall of the aircraft engine.

[0003] In practice, the sensing parts of the thermocouples and optical fibers installed on the temperature measuring wall of the aircraft engine not only conduct heat with the temperature measuring wall of the aircraft engine, but also have convective heat exchange with the fluid on one side of the temperature measuring wall, radiation heat exchange with the surrounding environment, and heat conduction between their leads. Therefore, the readings of the thermocouples and optical fibers can only represent the temperature of their sensing parts, and cannot accurately represent the temperature of the temperature measuring wall of the aircraft engine. Directly using their readings as the temperature of the temperature measuring wall of the aircraft engine may result in large deviations, affecting the analysis of the test results.

[0004] This application is proposed in view of the above-mentioned technical defects.

[0005] It should be noted that the disclosure of the above background technology content is only used to assist in understanding the inventive concept and technical solution of the present invention, and it does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above content has been disclosed on the filing date of this application, the above background technology should not be used to evaluate the novelty and creativity of the present application. Summary of the invention

[0006] The purpose of the present application is to provide a contact temperature sensor wall temperature measurement correction method to overcome or alleviate at least one of the known technical defects.

[0007] The technical solution of this application is:

[0008] A contact temperature sensor wall temperature measurement correction method, comprising:

[0009] Construct the convection heat transfer equation between the sensing part of the contact temperature sensor and the fluid on the temperature measuring wall: Φ1=h1A1(T f1 -T s );

[0010] Construct the radiation heat transfer equation between the sensing part of the contact temperature sensor and the surrounding environment:

[0011] Φ2=ε1A1σ(T r4 -T S 4 );

[0012] Construct the heat conduction equation between the sensing part and the lead of the contact temperature sensor:

[0013]

[0014] Construct the heat conduction equation between the sensing part of the contact temperature sensor and the temperature measuring wall:

[0015]

[0016] Establish the heat balance equation of the sensing part of the contact temperature sensor: Φ1+Φ2+Φ3+Φ4=0, and solve it to obtain the temperature of the temperature measuring wall surface;

[0017] in:

[0018] Φ1 is the convection heat transfer between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0019] h1 is the convection heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0020] A1 is the contact area between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0021] T f1 is the temperature of the fluid on one side of the temperature measuring wall;

[0022] T s is the temperature reading of the contact temperature sensor;

[0023] Φ2 is the radiation heat exchange between the sensing part of the contact temperature sensor and the surrounding environment;

[0024] ε1 is the emissivity of the sensing part of the contact temperature sensor;

[0025] σ is the blackbody radiation constant;

[0026] T r is the ambient radiation temperature;

[0027] Φ3 is the heat conduction between the sensing part of the contact temperature sensor and its lead wire;

[0028] d y is the diameter of the lead wire of the contact temperature sensor;

[0029] h y is the convection heat transfer coefficient between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0030] λy is the thermal conductivity of the lead material of the contact temperature sensor;

[0031] T ∞ is the far-end temperature of the lead wire of the contact temperature sensor;

[0032] th is the hyperbolic tangent function;

[0033] H is the length of the lead wire of the contact temperature sensor;

[0034] Φ4 is the heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall surface;

[0035] R c is the thermal resistance of the sensing part of the contact temperature sensor;

[0036] T w is the temperature of the measuring wall.

[0037] According to at least one embodiment of the present application, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the convection heat transfer coefficient h1 between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measurement wall is calculated by the following correlation formula:

[0038] Nu1=0.337Re1 0.8 Pr 1 / 3 ;

[0039]

[0040] in,

[0041] Nu1 is the Nusselt number between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0042] Re1 is the Reynolds number of the fluid on one side of the temperature measuring wall;

[0043] Pr is the Prandtl number;

[0044] u1 is the characteristic velocity of the fluid on one side of the temperature measuring wall;

[0045] l is the equivalent characteristic length of the temperature measuring wall;

[0046] v1 is the kinematic viscosity of the fluid on one side of the temperature measuring wall.

[0047] According to at least one embodiment of the present application, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the convection heat transfer coefficient h between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measurement wall is y Calculated by the following relationship:

[0048]

[0049] If the lead wire of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall:

[0050]

[0051] If the lead wire of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall:

[0052]

[0053] in,

[0054] Nu y is the Nusselt number between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0055] l y When the lead of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall, it is the length of the lead of the contact temperature sensor; when the lead of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall, it is the diameter of the lead of the contact temperature sensor;

[0056] λ y is the thermal conductivity of the lead wire of the contact temperature sensor.

[0057] According to at least one embodiment of the present application, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the thermal conductivity resistance R of the sensing part of the contact temperature sensor c Calculated by the following relationship:

[0058] Φ4=kA2(T f2 -T s );

[0059]

[0060] in,

[0061] k is the heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on the side facing away from the temperature measurement wall;

[0062] A2 is the contact area between the sensing part of the contact temperature sensor and the temperature measuring wall surface;

[0063] T f2 is the temperature of the fluid on the side facing away from the temperature measuring wall;

[0064] d1 is the equivalent inner diameter of the temperature measuring wall;

[0065] d2 is the equivalent outer diameter of the temperature measuring wall;

[0066] λ w is the thermal conductivity of the temperature measuring wall;

[0067] h2 is the convection heat transfer coefficient of the fluid on the side facing away from the temperature measuring wall.

[0068] According to at least one embodiment of the present application, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the contact temperature sensor is a thermocouple or an optical fiber. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 It is a flow chart of a method for correcting the wall temperature measurement of a contact temperature sensor provided in an embodiment of the present application;

[0070] Figure 2 It is a schematic diagram of the wall temperature measurement correction of the contact temperature sensor provided in the embodiment of the present application;

[0071] Figure 3 It is a schematic diagram of the principle of wall temperature measurement correction of a contact temperature sensor provided in an embodiment of the present application.

[0072] In order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; in addition, the drawings are used for illustrative purposes, and their positional relationships are limited to illustrative purposes and cannot be understood as limitations on this patent. DETAILED DESCRIPTION

[0073] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be further described in detail in detail and in detail in conjunction with the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0074] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall be the common meanings understood by the general technicians in the field to which this application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inside", "outside" and other words indicating orientation used in the description of this application are only used to indicate the relative direction or positional relationship, and do not imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, so it cannot be understood as a limitation on this application. The "first", "second", "third" and similar terms used in the description of this application are only used for descriptive purposes to distinguish different components, and cannot be understood as indicating or implying relative importance. The similar words "one", "one" or "the" used in the description of this application should not be understood as an absolute limitation on quantity, but should be understood as the existence of at least one. The similar words "including" or "comprising" used in the description of this application mean that the elements or objects appearing in front of the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0075] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installed", "connected", "connected" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. Technical personnel in the field can understand their specific meanings in this application according to the specific circumstances.

[0076] The following is combined with Figures 1 to 3 This application is described in further detail.

[0077] A contact temperature sensor wall temperature measurement correction method, comprising:

[0078] Construct the convection heat transfer equation between the sensing part of the contact temperature sensor and the fluid on the temperature measuring wall: Φ1=h1A1(T f1 -T s );

[0079] Construct the radiation heat transfer equation between the sensing part of the contact temperature sensor and the surrounding environment:

[0080] Φ2=ε1A1σ(T r 4 -T S 4 );

[0081] Construct the heat conduction equation between the sensing part and the lead of the contact temperature sensor:

[0082]

[0083] Construct the heat conduction equation between the sensing part of the contact temperature sensor and the temperature measuring wall:

[0084]

[0085] Establish the heat balance equation of the sensing part of the contact temperature sensor: Φ1+Φ2+Φ3+Φ4=0, and solve it to obtain the temperature of the temperature measuring wall surface;

[0086] in:

[0087] Φ1 is the convection heat transfer between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0088] h1 is the convection heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0089] A1 is the contact area between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0090] T f1 is the temperature of the fluid on one side of the temperature measuring wall;

[0091] T s is the temperature reading of the contact temperature sensor;

[0092] Φ2 is the radiation heat exchange between the sensing part of the contact temperature sensor and the surrounding environment;

[0093] ε1 is the emissivity of the sensing part of the contact temperature sensor;

[0094] σ is the blackbody radiation constant;

[0095] T r is the ambient radiation temperature;

[0096] Φ3 is the heat conduction between the sensing part of the contact temperature sensor and its lead wire;

[0097] d y is the diameter of the lead wire of the contact temperature sensor;

[0098] h y is the convection heat transfer coefficient between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0099] λ y is the thermal conductivity of the lead material of the contact temperature sensor;

[0100] T ∞is the far-end temperature of the lead wire of the contact temperature sensor;

[0101] th is the hyperbolic tangent function;

[0102] H is the length of the lead wire of the contact temperature sensor;

[0103] Φ4 is the heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall surface;

[0104] R c is the thermal resistance of the sensing part of the contact temperature sensor;

[0105] T w is the temperature of the measuring wall.

[0106] As for the contact temperature sensor wall temperature measurement correction method disclosed in the above embodiment, technicians in the field can understand that it takes into account the actual situation that there is heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall, convection heat transfer between the sensing part and the fluid on one side of the temperature measuring wall, radiation heat transfer between the sensing part and the surrounding environment, and heat conduction between the sensing part and the lead wire of the contact temperature sensor, and constructs the convection heat transfer equation between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall, the radiation heat transfer equation between the sensing part and the surrounding environment, the heat conduction equation between the sensing part and the lead wire, and the heat conduction equation between the sensing part and the temperature measuring wall, and then establishes the thermal balance equation of the sensing part of the contact temperature sensor, corrects the reading of the contact temperature sensor, and obtains the temperature of the temperature measuring wall with high accuracy.

[0107] In some optional embodiments, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the convection heat transfer coefficient h1 between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measurement wall is calculated by the following correlation formula:

[0108] Nu1=0.337Re1 0.8 Pr 1 / 3 ;

[0109]

[0110] in,

[0111] Nu1 is the Nusselt number between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0112] Re1 is the Reynolds number of the fluid on one side of the temperature measuring wall;

[0113] Pr is the Prandtl number;

[0114] u1 is the characteristic velocity of the fluid on one side of the temperature measuring wall;

[0115] l is the equivalent characteristic length of the temperature measuring wall;

[0116] v1 is the kinematic viscosity of the fluid on one side of the temperature measuring wall.

[0117] In some optional embodiments, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the convection heat transfer coefficient h between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measurement wall is y Calculated by the following relationship:

[0118]

[0119] If the lead wire of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall:

[0120]

[0121] If the lead wire of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall:

[0122]

[0123] in,

[0124] Nu y is the Nusselt number between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall;

[0125] l y When the lead of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall, it is the length of the lead of the contact temperature sensor; when the lead of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall, it is the diameter of the lead of the contact temperature sensor;

[0126] λ y is the thermal conductivity of the lead wire of the contact temperature sensor.

[0127] In some optional embodiments, in the above-mentioned contact temperature sensor wall surface temperature measurement correction method, the thermal conductivity resistance R of the sensing part of the contact temperature sensor c Calculated by the following relationship:

[0128] Φ4=kA2(T f2 -T s );

[0129]

[0130] in,

[0131] k is the heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on the side facing away from the temperature measurement wall;

[0132] A2 is the contact area between the sensing part of the contact temperature sensor and the temperature measuring wall surface;

[0133] Tf2 is the temperature of the fluid on the side facing away from the temperature measuring wall;

[0134] d1 is the equivalent inner diameter of the temperature measuring wall;

[0135] d2 is the equivalent outer diameter of the temperature measuring wall;

[0136] λ w is the thermal conductivity of the temperature measuring wall;

[0137] h2 is the convection heat transfer coefficient of the fluid on the side facing away from the temperature measuring wall.

[0138] Regarding the contact temperature sensor wall surface temperature measurement correction method disclosed in the above embodiment, it can be understood by those skilled in the art that the thermal conductivity resistance R of the sensing part of the contact temperature sensor is c It is difficult to obtain directly. Based on the fact that the heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall is equal to the heat transfer from the fluid on the side facing away from the temperature measuring wall to the sensing part of the contact temperature sensor, the heat transfer equation between the sensing part of the temperature sensor and the fluid on the side facing away from the temperature measuring wall is constructed as Φ4=kA2(T f2 -T s ), the heat transfer coefficient k between the sensing part of the contact temperature sensor and the fluid on the side facing away from the temperature measurement wall is obtained, and then the thermal resistance R of the sensing part of the contact temperature sensor is calculated. c .

[0139] In some optional embodiments, in the above-mentioned contact temperature sensor wall temperature measurement correction method, the contact temperature sensor is a thermocouple or an optical fiber, and the temperature measurement wall surface can specifically be a wall surface where temperature measurement is required in aircraft engine testing.

[0140] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0141] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for correcting wall temperature measurement of a contact temperature sensor, characterized in that: include: Construct the convection heat transfer equation between the sensing part of the contact temperature sensor and the fluid on the temperature measuring wall: Φ1=h1A1(T f1 -T s ); Construct the radiation heat transfer equation between the sensing part of the contact temperature sensor and the surrounding environment: Φ2=ε1A1σ(T r 4 -T S 4 ); Construct the heat conduction equation between the sensing part and the lead of the contact temperature sensor: Construct the heat conduction equation between the sensing part of the contact temperature sensor and the temperature measuring wall: Establish the heat balance equation of the sensing part of the contact temperature sensor: Φ1+Φ2+Φ3+Φ4=0, and solve it to obtain the temperature of the temperature measuring wall surface; in: Φ1 is the convection heat transfer between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall; h1 is the convection heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall; A1 is the contact area between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall; T f1 is the temperature of the fluid on one side of the temperature measuring wall; T s is the temperature reading of the contact temperature sensor; Φ2 is the radiation heat exchange between the sensing part of the contact temperature sensor and the surrounding environment; ε1 is the emissivity of the sensing part of the contact temperature sensor; σ is the blackbody radiation constant; T r is the ambient radiation temperature; Φ3 is the heat conduction between the sensing part of the contact temperature sensor and its lead wire; d y is the diameter of the lead wire of the contact temperature sensor; h y is the convection heat transfer coefficient between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall; λ y is the thermal conductivity of the lead material of the contact temperature sensor; T ∞ is the far-end temperature of the lead wire of the contact temperature sensor; th is the hyperbolic tangent function; H is the length of the lead wire of the contact temperature sensor; Φ4 is the heat conduction between the sensing part of the contact temperature sensor and the temperature measuring wall surface; R c is the thermal resistance of the sensing part of the contact temperature sensor; T w is the temperature of the measuring wall.

2. The contact temperature sensor wall temperature measurement correction method according to claim 1, characterized in that: The convection heat transfer coefficient h1 between the sensing part of the contact temperature sensor and the fluid on the temperature measuring wall is calculated by the following correlation formula: <h2 style=";text-align:left;direction:ltr">Nu1 = 0.337Re1<h2 style=";text-align:left;direction:ltr"> 0.8 <h2 style=";text-align:left;direction:ltr"> Pr<h2 style=";text-align:left;direction:ltr"> 1 / 3 <h2 style=";text-align:left;direction:ltr"> ; in, Nu1 is the Nusselt number between the sensing part of the contact temperature sensor and the fluid on one side of the temperature measuring wall; Re1 is the Reynolds number of the fluid on one side of the temperature measuring wall; Pr is the Prandtl number; u1 is the characteristic velocity of the fluid on one side of the temperature measuring wall; l is the equivalent characteristic length of the temperature measuring wall; v1 is the kinematic viscosity of the fluid on one side of the temperature measuring wall.

3. The contact temperature sensor wall temperature measurement correction method according to claim 2, characterized in that: The convection heat transfer coefficient hy between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall is calculated by the following correlation formula: If the lead wire of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall: If the lead wire of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall: in, Nu y is the Nusselt number between the lead wire of the contact temperature sensor and the fluid on one side of the temperature measuring wall; l y When the lead of the contact temperature sensor is parallel to the fluid direction on one side of the temperature measuring wall, it is the length of the lead of the contact temperature sensor; when the lead of the contact temperature sensor is perpendicular to the fluid direction on one side of the temperature measuring wall, it is the diameter of the lead of the contact temperature sensor; λ y is the thermal conductivity of the lead wire of the contact temperature sensor.

4. The contact temperature sensor wall temperature measurement correction method according to claim 3, characterized in that: Thermal resistance R of the sensing part of the contact temperature sensor c Calculated by the following relationship: Φ4=kA2(T f2 -T s ); in, k is the heat transfer coefficient between the sensing part of the contact temperature sensor and the fluid on the side facing away from the temperature measurement wall; A2 is the contact area between the sensing part of the contact temperature sensor and the temperature measuring wall surface; T f2 is the temperature of the fluid on the side facing away from the temperature measuring wall; d1 is the equivalent inner diameter of the temperature measuring wall; d2 is the equivalent outer diameter of the temperature measuring wall; λ w is the thermal conductivity of the temperature measuring wall; h2 is the convection heat transfer coefficient of the fluid on the side facing away from the temperature measuring wall.

5. The contact temperature sensor wall temperature measurement correction method according to claim 4, characterized in that: The contact temperature sensor is a thermocouple or an optical fiber.

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