Thermocouple with high total temperature recovery coefficient and wide response time range

Abstract

The invention discloses a thermocouple with a high total temperature recovery coefficient and a wide response time range, which is characterized in that the structure of an exposed temperature measurement part out of a shell is adjusted, only one opening structure of the exposed temperature measurement part is improved into a surrounding structure surrounding the exposed temperature measurement part, and an air inlet hole and an air outlet hole are formed in the corresponding positions of the surrounding structure, so that the exposed temperature measurement part is protected from being damaged. An airflow channel is formed between the air inlet hole and the air outlet hole, so that the total temperature recovery coefficient of the thermocouple is increased; furthermore, by adjusting the length of the exposed temperature measurement part in the length direction of the high-temperature glass powder sintering section and adjusting the powder proportion of the high-temperature glass powder sintering section, the response time of a thermocouple can be ensured on the basis of obtaining a large total temperature recovery coefficient; meanwhile, due to the arrangement of the high-temperature glass powder sintering section, insulation failure cannot be caused when the thermocouple is used in an oil-rich, high-temperature and humid environment.

Description

Technical Field

[0001] This invention relates to the field of thermocouple technology, and specifically to a thermocouple with a high total temperature recovery coefficient and a wide response time range. Background Technology

[0002] The temperature of high-temperature, high-speed gas in aero-engines or gas turbines is primarily measured using thermocouple temperature sensors. To accurately measure the total temperature of the high-speed gas flow, the total temperature recovery coefficient of the thermocouple is crucial. Furthermore, due to differences in temperature measurement systems and depth of measurement, thermocouple temperature sensors must also have varying response times. Therefore, there is an urgent need for a thermocouple temperature sensor that, after calibration, can possess a high total temperature recovery coefficient and a wide response time range to adapt to various temperature measurements and data acquisition tasks involving high-temperature, high-speed gas. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a thermocouple with a high total temperature recovery coefficient and a wide response time range. It includes a high-temperature resistant glass powder sintered section and a thermoelectric wire passing through the high-temperature resistant glass powder sintered section. The portion of the thermoelectric wire outside both ends of the high-temperature glass powder sintered section comprises a positive and negative electrode portion and an exposed temperature measuring portion. A first shell of equal length to the high-temperature glass powder sintered section is disposed outside the high-temperature glass powder sintered section. An outer shell is further disposed outside the first shell, comprising a first outer shell that encloses and fixes at least a portion of the length of the first shell and a second outer shell that surrounds the exposed temperature measuring portion. The portion of the second outer shell to the right of the exposed temperature measuring portion is a temperature measuring section, on which at least two air inlets are formed. One air outlet is provided on the second outer shell circumferentially around the exposed temperature measuring portion.

[0004] Furthermore, the area ratio of the air inlet to the air outlet is 1.02-2;

[0005] Furthermore, the diameter of the air outlet is greater than or equal to 2 mm.

[0006] Furthermore, the distance L1 from the center of the vent to the right end of the first housing is 1-6 mm.

[0007] Furthermore, the length L2 of the exposed temperature measuring part in the length direction of the high-temperature glass powder sintering section is 3.2-7mm.

[0008] Furthermore, the thermoelectric wires are two wires arranged in parallel.

[0009] Furthermore, the high-temperature glass powder sintering section comprises the following components by weight percentage: 56.2-58.1 wt% SiO2, 32.3-33.2 wt% MgO, 6.8-9.3 wt% B2O3 and 1.9-2.2 wt% P2O5.

[0010] Furthermore, the high-temperature glass powder sintering section comprises the following components by weight percentage: 45.2-48.5 wt% SiO2, 26.2-31.0 wt% MgO, 9.2-11.3 wt% B2O3, 1.9-2.5 wt% P2O5 and 9.4-14.8 wt% ZnO.

[0011] Furthermore, it also includes a flange with mounting holes. The end of the outer shell away from the temperature measuring section extends into the mounting holes and is fixedly connected to the flange. The flange is also provided with a mounting cover that covers the mounting holes. An insulating seat is provided inside the mounting cover. Electrode bolts extend into the mounting cover through through holes provided on the mounting cover and are fixed together with the insulating seat. The positive and negative electrode portions are connected to the electrode bolts inside the mounting cover.

[0012] In the above technical solution, by adjusting the structure of the exposed temperature measuring part outside the outer shell, the structure is improved from a single opening in the exposed temperature measuring part to a surrounding structure that encloses the exposed temperature measuring part. Air inlets and outlets are provided at corresponding positions in the surrounding structure, creating an airflow channel between the air inlets and outlets, thus increasing the total temperature recovery coefficient of the thermocouple. Furthermore, by adjusting the area ratio of the air inlets and outlets, the thermocouples can have different total temperature recovery coefficients. As the area increases, the response time of the thermocouple decreases. The applicant achieves a large total temperature recovery coefficient while ensuring the thermocouple's response time by adjusting the length of the exposed temperature measuring part in the length direction of the high-temperature glass powder sintering section and by adjusting the powder ratio of the high-temperature glass powder sintering section. Simultaneously, the high-temperature glass powder sintering section ensures that the thermocouple will not fail in oil-rich, high-temperature, and humid environments. After testing, the total temperature recovery coefficient of the thermocouples in the above technical solution is 93.2%-99.7%, and the response time is 0.3-7s. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the thermocouple with high total temperature recovery coefficient and wide response time range of the present invention;

[0015] Figure 2This is a schematic diagram of the thermocouple with high total temperature recovery coefficient and wide response time range of the present invention from another direction;

[0016] Figure 3 This is a schematic diagram of the structure of a thermocouple in the prior art;

[0017] The reference numerals in the figure are as follows: 1-High-temperature glass powder sintering section; 2-Positive and negative electrode parts; 3-Exposed temperature measuring part; 4-First shell; 5-First outer shell; 6-Second outer shell; 7-Temperature measuring section; 8-Air inlet; 9-Air outlet; 10-Flange; 11-Mounting hole; 12-Mounting cover; 13-Insulating base; 14-Electrode bolt. Detailed Implementation

[0018] The present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Other embodiments obtained by those skilled in the art within the scope of the embodiments of the present invention without inventive effort are all within the protection scope of the present invention.

[0019] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Example 1

[0023] like Figure 1 and 2As shown, this embodiment discloses a thermocouple with a high total temperature recovery coefficient and a wide response time range, which includes a high-temperature resistant glass powder sintered section 1 and a thermoelectric wire passing through the high-temperature resistant glass powder sintered section 1. The portions of the thermoelectric wire located outside the two ends of the high-temperature resistant glass powder sintered section 1 are respectively positive and negative electrode portions 2 and exposed temperature measuring portions 3. The positive and negative electrode portions 2 include the two ends of the thermoelectric wire, and the exposed temperature measuring portions 3 are the bent portions of the thermoelectric wire. A first shell 4 of equal length to the high-temperature glass powder sintering section 1 is provided on the outer surface of the high-temperature glass powder sintering section 1. During processing, the high-temperature glass powder is compacted into the first shell 4 by a machine, and a thermoelectric electrode wire is pre-embedded at the same time, and then sintered. An outer shell is provided outside the first shell 4. The outer shell includes a first outer shell 5 that wraps and fixes at least a portion of the length of the first shell and a second outer shell 6 that surrounds the exposed temperature measuring part 3. The second outer shell 6 forms a cavity to accommodate the exposed temperature measuring part 3 and extends to the right side of the exposed temperature measuring part 3 to form a temperature measuring section 7. The free end of the temperature measuring section 7 is arc-shaped. The first outer shell 5 and the second outer shell 6 are preferably integrally formed and fixed to the first outer shell 4 by argon arc welding. At least two air inlets 8 are formed on the temperature measuring section 7. In this embodiment, there are two air inlets 8. One air outlet 9 is provided on the second outer shell in the circumferential direction of the exposed temperature measuring part. An air flow channel for air flow is formed between the air inlets 8 and the air outlet 9 in the second outer shell 6. Preferably, the centers of the air inlets 8 and the air outlet 9 are in one plane and are located on both sides of the central axis of the high-temperature resistant glass powder sintering section 1.

[0024] In one embodiment, the area ratio of the air inlet 8 to the air outlet 9 is 1.02-2.

[0025] In one embodiment, the diameter of the vent 9 is greater than or equal to 2 mm, and it can be reasonably processed on the second outer shell.

[0026] In one embodiment, the distance L1 from the center of the vent 9 to the right end of the first housing 4 is 1-6 mm.

[0027] In one embodiment, the length L2 of the exposed temperature measuring part in the length direction of the high-temperature glass powder sintering section is 3.2-7 mm.

[0028] In one embodiment, the high-temperature glass powder sintering section comprises the following components by weight percentage: 56.2-58.1 wt% SiO2, 32.3-33.2 wt% MgO, 6.8-9.3 wt% B2O3 and 1.9-2.2 wt% P2O5.

[0029] In one embodiment, the high-temperature glass powder sintering section comprises the following components by weight percentage: 45.2-48.5 wt% SiO2, 26.2-31.0 wt% MgO, 9.2-11.3 wt% B2O3, 1.9-2.5 wt% P2O5, and 9.4-14.8 wt% ZnO.

[0030] In one embodiment, the system further includes a flange 10 for fixing the thermocouple to the measurement area. The flange 10 has mounting holes 11, and the end of the outer casing away from the temperature measuring section 7 extends into the mounting holes 11 and is fixedly connected to the flange 10. This connection method is preferably argon arc welding. The flange 10 also has a mounting cover 12 that covers the mounting holes 11. The fixing method between the mounting cover 12 and the flange 10 can be varied, such as snap-fit, threaded connection, or welding. An insulating seat 13 is provided inside the mounting cover 12. Electrode bolts 14 extend into the mounting cover 12 through through holes and are fixed to the insulating seat 13. This fixing method is conventional and will not be elaborated further. The positive and negative electrode portions are connected to the electrode bolts 14 inside the mounting cover 12. Since the positive and negative electrode portions are divided into positive and negative poles, the electrode bolts 14 also include positive and negative bolts. They are generally connected by welding, which is also a conventional structural design and will not be elaborated further.

[0031] To ensure signal transmission stability, in this embodiment, the thermoelectric wires are arranged in parallel as two wires. If one wire malfunctions, the other can continue to output a signal. Naturally, the positive and negative electrode portions include two sets of positive and negative poles, and correspondingly, the electrode bolts 14 also include two sets.

[0032] To verify the effectiveness of the aforementioned thermocouples, thermocouples were fabricated using the following parameters for testing. Common parameters include: the diameter of the thermoelectric wire is 1.2 mm; the first housing is made of GH3039 steel with a thickness of 0.5 mm and an inner diameter of 6 mm; the outer shell is made of GH3039 steel with a thickness of 1 mm and an inner diameter of 7 mm, wherein the temperature measuring section is formed by a diameter reduction, with an outer diameter of 6 mm and an arc-shaped end with a length of 15.5 mm; the length from the right end of the flange 10 to the right end of the temperature measuring section is 67 mm; the diameter of the vent is 2 mm; and L1 is 1 mm.

[0033] Example 2

[0034] The parameters of this embodiment are as follows: the area ratio of the air inlet to the air outlet is 1.05; L2 is 6.5mm; the high-temperature glass powder sintering section includes the following components by weight percentage: 56.2wt% SiO2, 32.3wt% MgO, 9.3wt% B2O3 and 2.2wt% P2O5.

[0035] Example 3

[0036] The parameters of this embodiment are as follows: the area ratio of the air inlet to the air outlet is 2; L2 is 7mm; the high-temperature glass powder sintering section includes the following components by weight percentage: 58.1wt% SiO2, 33.2wt% MgO, 6.8wt% B2O3 and 1.9wt% P2O5.

[0037] Example 4

[0038] The parameters of this embodiment are as follows: the area ratio of the air inlet to the air outlet is 1.5; L2 is 3.6 mm; the high-temperature glass powder sintering section includes the following components by weight percentage: 48.5 wt% SiO2, 31.0 wt% MgO, 9.2 wt% B2O3, 1.9 wt% P2O5 and 9.4 wt% ZnO.

[0039] Example 5

[0040] The parameters of this embodiment are as follows: the area ratio of the air inlet to the air outlet is 1.02; L2 is 3.2 mm; the high-temperature glass powder sintering section includes the following components by weight percentage: 45.2 wt% SiO2, 26.2 wt% MgO, 11.3 wt% B2O3, 2.5 wt% P2O5 and 14.8 wt% ZnO.

[0041] Example 6

[0042] The parameters of this embodiment are as follows: the area ratio of the air inlet to the air outlet is 1.2; L2 is 5.2 mm; the high-temperature glass powder sintering section includes the following components by weight percentage: 46.5 wt% SiO2, 30.2 wt% MgO, 10.1 wt% B2O3, 2.1 wt% P2O5 and 11.1 wt% ZnO.

[0043] Comparative Example

[0044] This comparative example was prepared with reference to Example 5, the difference being: as follows Figure 3 As shown, the outer casing has an opening at the right end of the exposed temperature measuring section, without a temperature measuring section or an air vent.

[0045] Test case

[0046] Thermocouples obtained using the parameters of Examples 2-6 and the comparative example were tested using JJF1049-1995 "Specification for Dynamic Response Calibration of Temperature Sensors". The total temperature recovery parameters of the thermocouples in Examples 2-6 were 96.2%, 98.8%, 93.2%, 99.7%, and 97.5%, with response times of 1.5s, 5.2s, 0.3s, 7s, and 3.2s, respectively. In contrast, the total temperature recovery parameter of the thermocouple in the comparative example was 76%, with a response time of 7.2s. These data show that the response time of the thermocouples prepared according to the present invention is not significantly different from that of the comparative example. However, the total temperature recovery coefficient of the thermocouples prepared according to the present invention is much higher than that of the thermocouples prepared according to the comparative example, reaching a maximum of 99.7%.

[0047] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A thermocouple with a high total temperature recovery coefficient and a wide response time range, characterized in that, The device includes a high-temperature resistant glass powder sintering section and a thermoelectric wire passing through the high-temperature resistant glass powder sintering section. The portion of the thermoelectric wire located outside both ends of the high-temperature glass powder sintering section is a positive and negative electrode portion and an exposed temperature measuring portion. A first shell of the same length as the high-temperature glass powder sintering section is provided outside the high-temperature glass powder sintering section. An outer shell is also provided outside the first shell. The outer shell includes a first outer shell that wraps and fixes at least a portion of the length of the first shell and a second outer shell that surrounds the exposed temperature measuring portion. The portion of the second outer shell to the right of the exposed temperature measuring portion is a temperature measuring section, and at least two air inlets are formed on the temperature measuring section. One air outlet is provided on the second outer shell circumferentially around the exposed temperature measuring portion.

2. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The area ratio of the air inlet to the air outlet is 1.02-2.

3. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The diameter of the air outlet is greater than or equal to 2 mm.

4. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The distance L1 from the center of the vent to the right end of the first housing is 1-6 mm.

5. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The length L2 of the exposed temperature measuring part in the longitudinal direction of the high-temperature glass powder sintering section is 3.2-7 mm.

6. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The thermoelectric wires are two wires arranged in parallel.

7. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The high-temperature glass powder sintering section comprises the following components by weight percentage: 56.2-58.1 wt% SiO2, 32.3-33.2 wt% MgO, 6.8-9.3 wt% B2O3 and 1.9-2.2 wt% P2O5.

8. The thermocouple with high total temperature recovery coefficient and wide response time range according to claim 1, characterized in that, The high-temperature glass powder sintering section comprises the following components by weight percentage: 45.2-48.5 wt% SiO2, 26.2-31.0 wt% MgO, 9.2-11.3 wt% B2O3, 1.9-2.5 wt% P2O5, and 9.4-14.8 wt% ZnO.

9. The thermocouple with high total temperature recovery coefficient and wide response time range according to claims 1-8, characterized in that, It also includes a flange with mounting holes. The end of the outer shell away from the temperature measuring section extends into the mounting holes and is fixedly connected to the flange. The flange is also provided with a mounting cover that covers the mounting holes. An insulating seat is provided inside the mounting cover. Electrode bolts extend into the mounting cover through through holes provided on the mounting cover and are fixed together with the insulating seat. The positive and negative electrode portions are connected to the electrode bolts inside the mounting cover.

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