Graphite heater protection clamp in open environment and use method thereof

Abstract

The invention belongs to the technical field of structural thermal tests, and particularly relates to a graphite heater protection clamp in an open environment and a use method thereof. According to the protective clamp, the turbine pipe is provided with a nitrogen inlet, a hot air outlet and a cold air outlet; a double-cavity air vent is formed in the lower wall surface of the quartz glass protective cover, and a nitrogen outlet is formed in the side wall surface of the quartz glass protective cover; the graphite heater is mounted in the quartz glass protective cover, and the upper wall surface and the side wall surface of the graphite heater are wrapped by a heat insulation cover; the quartz glass cooling cover is installed at the lower end of the quartz glass protective cover, the quartz glass cooling cover is communicated with the quartz glass protective cover through the double-cavity ventilation opening, and a cold air inlet is formed in the side wall face of the quartz glass cooling cover. And a cold air inlet of the quartz glass cooling cover is connected with a cold air outlet of the turbine pipe. According to the graphite heater, a self-cooling positive-pressure nitrogen environment is constructed, so that the graphite heater can be used in an open environment.

Description

Technical Field

[0001] The present application belongs to the technical field of structural thermal testing, and in particular relates to a graphite heater protection fixture in an open environment and a method of using the same. Background Art

[0002] Structural thermal testing is an important test method for evaluating the long-term thermal response of materials and structures related to military aircraft. The maximum heating temperature of graphite heaters reaches 2000°C, and they are often used in ultra-high temperature military aircraft structural thermal tests. Since graphite heaters are extremely easy to oxidize or even burn at high temperatures, heating tests are usually carried out in closed containers. The closed container is filled with inert gas or evacuated to a vacuum to ensure that no oxygen reacts with the graphite heater, which greatly limits the application scenarios of graphite heaters.

[0003] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0004] The purpose of the present application is to provide a graphite heater protection clamp in an open environment and a method of using the same, so as to solve at least one problem existing in the prior art.

[0005] The technical solution of this application is:

[0006] A graphite heater protection fixture in an open environment, comprising:

[0007] a turbine tube having a nitrogen inlet, a hot gas outlet, and a cold gas outlet;

[0008] A quartz glass protective cover, wherein the lower wall of the quartz glass protective cover is provided with a double-cavity vent, and the side wall is provided with a nitrogen outlet;

[0009] A graphite heater, wherein the graphite heater is installed inside the quartz glass protective cover, and the upper wall surface and the side wall surface of the graphite heater are wrapped by a heat insulation cover;

[0010] A quartz glass cooling hood is installed at the lower end of the quartz glass protective hood, the quartz glass cooling hood is communicated with the quartz glass protective hood through the double-cavity vent, a cold air inlet is provided on the side wall of the quartz glass cooling hood, and the cold air inlet of the quartz glass cooling hood is connected to the cold air outlet of the turbine tube.

[0011] In at least one embodiment of the present application, the quartz glass protective cover is square.

[0012] In at least one embodiment of the present application, the quartz glass cooling cover is U-shaped.

[0013] A second aspect of the present application provides a method for using a graphite heater protection fixture in an open environment, based on the graphite heater protection fixture in an open environment as described above, comprising:

[0014] Heating test quasi-stage: high-pressure nitrogen is introduced into the turbine tube from the nitrogen inlet, low-temperature nitrogen is discharged from the cold air outlet of the turbine tube, and enters the quartz glass cooling cover through the cold air inlet. The low-temperature nitrogen completes heat exchange with the quartz glass cooling cover and becomes normal-temperature nitrogen. The normal-temperature nitrogen enters the quartz glass protective cover through the double-cavity vent, and is finally discharged through the nitrogen outlet of the quartz glass protective cover; the process of introducing high-pressure nitrogen into the turbine tube from the nitrogen inlet continues for a predetermined time, and the air in the quartz glass cooling cover and the quartz glass protective cover is completely replaced by nitrogen;

[0015] Heating test stage: keep high-pressure nitrogen flowing into the turbine tube from the nitrogen inlet, set the test piece under the quartz glass cooling cover, power on the graphite heater, and the heat radiated by the graphite heater is radiated to the test piece through the quartz glass protective cover and the quartz glass cooling cover in turn.

[0016] In at least one embodiment of the present application, during the heating test phase, the pressure of the high-pressure nitrogen gas introduced into the turbine tube is 6.9-8 bar.

[0017] In at least one embodiment of the present application, during the heating test phase, high-pressure nitrogen is introduced into the turbine tube from the nitrogen inlet for 30 minutes, and then the air in the quartz glass cooling cover and the quartz glass protective cover is completely replaced by nitrogen.

[0018] The invention has at least the following beneficial technical effects:

[0019] The graphite heater protection fixture in an open environment of the present application constructs a self-cooling positive pressure nitrogen environment, so that the graphite heater can be used in an open environment like an ordinary heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a graphite heater protection clamp in an open environment according to an embodiment of the present application.

[0021] in:

[0022] 1-turbine tube; 2-quartz glass protective cover; 3-graphite heater; 4-heat insulation cover; 5-quartz glass cooling cover. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0024] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present application.

[0025] The following is combined with Figure 1 This application is described in further detail.

[0026] A first aspect of the present application provides a graphite heater protection fixture for an open environment, comprising: a turbine tube 1, a quartz glass protection cover 2, a graphite heater 3, a heat insulation cover 4 and a quartz glass cooling cover 5.

[0027] Specifically, Figure 1 As shown, the turbine tube 1 has a nitrogen inlet, a hot air outlet and a cold air outlet; the turbine tube is a cold air generating device, and high-pressure nitrogen enters from the nitrogen inlet. Under the action of the internal structure of the turbine tube, the nitrogen close to the tube wall rotates at a high speed, absorbs heat and heats up before being discharged from the hot air outlet of the turbine tube, and the nitrogen close to the central axis rotates at a low speed, releases heat and cools down before being discharged from the cold air outlet.

[0028] The lower wall surface of the quartz glass protective cover 2 is provided with a double-cavity vent, and the side wall surface is provided with a nitrogen outlet; the graphite heater 3 is installed inside the quartz glass protective cover 2, and the upper wall surface and the side wall surface of the graphite heater 3 are wrapped by the heat insulation cover 4; the quartz glass cooling cover 5 is installed at the lower end of the quartz glass protective cover 2, and the quartz glass cooling cover 5 is connected to the quartz glass protective cover 2 through the double-cavity vent, and the side wall surface of the quartz glass cooling cover 5 is provided with a cold air inlet, and the cold air inlet of the quartz glass cooling cover 5 is connected to the cold air outlet of the turbine tube 1.

[0029] In this embodiment, the quartz glass protective cover 2 is square-shaped, and the quartz glass cooling cover 5 is U-shaped. The quartz glass protective cover 2 and the quartz glass cooling cover 5 can be formed in an integral structure.

[0030] In the graphite heater protection fixture in an open environment of the present application, the quartz glass protection cover 2 is arranged on the upper side, and the quartz glass cooling cover 5 is arranged on the lower side, and the two are connected through a double-cavity vent. The quartz glass cooling cover 5 is connected to the turbine tube 1 through the cold air inlet, and the quartz glass protection cover 2 is connected to the outside through the nitrogen outlet. The graphite heater 3 is placed in the quartz glass protection cover 2, and the upper wall and side wall of the graphite heater 3 are wrapped with a heat insulation cover 4 of a heat insulation material, and only the lower wall used to heat the test piece is exposed.

[0031] A second aspect of the present application provides a method for using a graphite heater protection fixture in an open environment, comprising:

[0032] Heating test quasi-stage: high-pressure nitrogen is introduced into the turbine tube 1 from the nitrogen inlet, low-temperature nitrogen is discharged from the cold air outlet of the turbine tube 1, and enters the quartz glass cooling cover 5 through the cold air inlet. The low-temperature nitrogen completes heat exchange with the quartz glass cooling cover 5 and becomes normal-temperature nitrogen. The normal-temperature nitrogen enters the quartz glass protective cover 2 through the double-cavity vent, and is finally discharged through the nitrogen outlet of the quartz glass protective cover 2; the process of introducing high-pressure nitrogen into the turbine tube 1 from the nitrogen inlet continues for a predetermined time, and the air in the quartz glass cooling cover 5 and the quartz glass protective cover 2 is completely replaced by nitrogen;

[0033] Heating test stage: keep high-pressure nitrogen flowing into the turbine tube 1 from the nitrogen inlet, set the test piece under the quartz glass cooling cover 5, power on the graphite heater 3, and radiate the heat from the graphite heater 3 to the test piece through the quartz glass protective cover 2 and the quartz glass cooling cover 5 in turn.

[0034] In one embodiment of the present application, during the heating test quasi-stage, the pressure of the high-pressure nitrogen introduced into the turbine tube 1 is 6.9 to 8 bar; and after the high-pressure nitrogen is introduced into the turbine tube 1 from the nitrogen inlet for 30 minutes, the air in the quartz glass cooling cover 5 and the quartz glass protective cover 2 is completely replaced by nitrogen.

[0035] The method for using the graphite heater protection fixture in an open environment of the present application is that during the heating test phase, high-pressure nitrogen is kept passing through the nitrogen inlet into the turbine tube 1. The low-temperature nitrogen generated by the high-pressure nitrogen through the turbine tube 1 can prevent the temperature of the quartz glass cooling cover 5 and the quartz glass protective cover 2 from being too high; at the same time, the room-temperature nitrogen after the low-temperature nitrogen and the quartz glass cooling cover 5 complete the heat exchange can always maintain the positive pressure nitrogen environment in the quartz glass protective cover 2, and the outside air cannot enter the quartz glass protective cover 2, and the graphite heater 3 will not be oxidized. The heat radiated by the graphite heater 3 can be radiated to the test piece through the transparent quartz glass protective cover 2 and the quartz glass cooling cover 5 to realize the heating process.

[0036] The graphite heater protection fixture in an open environment of the present application and the method of using the same protect the graphite heater 3 through a self-cooling positive pressure nitrogen environment, so that the graphite heater 3 can be used in an open environment, greatly expanding the application scenarios of the graphite heater 3. The present application is not only applicable to military aircraft structural thermal tests, but also to other similar occasions, so it also has broad application prospects in the civilian field.

[0037] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A graphite heater protection fixture in an open environment, characterized in that: include: A turbine tube (1), the turbine tube (1) having a nitrogen inlet, a hot gas outlet and a cold gas outlet; A quartz glass protective cover (2), wherein a double-cavity vent is provided on a lower wall surface of the quartz glass protective cover (2), and a nitrogen outlet is provided on a side wall surface; A graphite heater (3), wherein the graphite heater (3) is installed inside the quartz glass protective cover (2), and the upper wall surface and the side wall surface of the graphite heater (3) are wrapped by a heat insulation cover (4); A quartz glass cooling hood (5), the quartz glass cooling hood (5) being mounted at the lower end of the quartz glass protective hood (2), the quartz glass cooling hood (5) being connected to the quartz glass protective hood (2) via the double-chamber vent, a cold air inlet being provided on the side wall of the quartz glass cooling hood (5), and the cold air inlet of the quartz glass cooling hood (5) being connected to the cold air outlet of the turbine tube (1).

2. The graphite heater protection fixture for an open environment according to claim 1, characterized in that: The quartz glass protective cover (2) is square.

3. The graphite heater protection fixture for an open environment according to claim 1, characterized in that: The quartz glass cooling cover (5) is U-shaped.

4. A method for using a graphite heater protection fixture in an open environment, based on the graphite heater protection fixture in an open environment according to any one of claims 1 to 3, characterized in that: include: Heating test quasi-stage: high-pressure nitrogen is introduced into the turbine tube (1) from the nitrogen inlet, low-temperature nitrogen is discharged from the cold air outlet of the turbine tube (1), and enters the quartz glass cooling cover (5) through the cold air inlet. The low-temperature nitrogen completes heat exchange with the quartz glass cooling cover (5) and becomes room-temperature nitrogen. The room-temperature nitrogen enters the quartz glass protective cover (2) through the double-cavity vent and is finally discharged through the nitrogen outlet of the quartz glass protective cover (2); high-pressure nitrogen is introduced into the turbine tube (1) from the nitrogen inlet for a predetermined time, and the air in the quartz glass cooling cover (5) and the quartz glass protective cover (2) is completely replaced by nitrogen; Heating test stage: high-pressure nitrogen is kept flowing into the turbine tube (1) from the nitrogen inlet, the test piece is placed below the quartz glass cooling cover (5), the graphite heater (3) is powered, and the heat radiated by the graphite heater (3) is radiated to the test piece through the quartz glass protective cover (2) and the quartz glass cooling cover (5) in sequence.

5. The method for using the graphite heater protection fixture in an open environment according to claim 4, characterized in that: During the heating test phase, the pressure of the high-pressure nitrogen gas introduced into the turbine tube (1) is 6.9 to 8 bar.

6. The method for using the graphite heater protection fixture in an open environment according to claim 5, characterized in that: During the heating test phase, high pressure nitrogen was introduced into the turbine tube (1) from the nitrogen inlet for 30 minutes, and the air in the quartz glass cooling cover (5) and the quartz glass protective cover (2) was completely replaced by nitrogen.

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