High-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers

Abstract

A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers uses single-crystal fibers upon crystal orientation optimization and/or doping ion modification as the probes of ultrasonic temperature sensors. Through crystal orientation optimization and/or doping modification of the single-crystal fibers, the invention improves the density and structural disorders of the single-crystal fibers while maintaining their structural stability to reduce the propagation speed of the ultrasonic waves in single-crystal fibers in a high-temperature environment, thus increasing the delay time between the reflected signals of the sensitive areas and improve the sensitivity of temperature measurements.

Claims

1. A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers, characterized in that it uses single-crystal fibers upon crystal orientation optimization and/or doping ion modification as the probes of ultrasonic temperature sensors.

2. The said temperature measurement method according to claim 1, characterized in that it uses single-crystal fibers upon doping ion modification only or those having undergone both crystal orientation optimization and doping ion modification as the probes of ultrasonic temperature sensors; preferably, it uses single-crystal fibers having undergone both crystal orientation optimization and doping ion modification as the probes of ultrasonic temperature sensors.

3. The said temperature measurement method according to claim 1, characterized in that the crystal orientations of the single-crystal fibers are <100>, <110>, <111>, <120>, or <112>; preferably, the crystal orientations of the single-crystal fibers are those with the minimum elastic modulus.

4. The said temperature measurement method according to claim 1, characterized in that the doping ions used in the doping ion modification process of the single-crystal fibers are transition metal cations, rare-earth metal cations, or cations that can be doped by the modified single-crystal fibers, or a combination of any two of them.

5. The said temperature measurement method according to claim 4, characterized in that the transition metal cations are one or more selected from among the Cr.sup.3+, Mn.sup.2+, Fe.sup.3+, Zn.sup.2+, Cu.sup.2+, and Sc.sup.3+; the rare-earth metal cations are one or more selected from among the Yb.sup.3+, Nd.sup.3+, Er.sup.3+, Dy.sup.3+, Lu.sup.3+, and Ho.sup.3+; the other cations that can be doped by the single-crystal fibers are one or more selected from among the Mg.sup.2+, Al.sup.3+, Si.sup.4+, Ga.sup.3+, and Ca.sup.2+.

6. The said temperature measurement method according to claim 1, characterized in that the doping modification is single doping or co-doping, and the doping method is melt doping, ion injection, or ion diffusion.

7. The said temperature measurement method according to claim 1, characterized in that the doping amount of the doping ions varies between 0.1 at % and 50 at % and is preferred to be between 0.5 at % and 10 at %.

8. The said temperature measurement method according to claim 1, characterized in that the said single-crystal fiber temperature measurement method measures temperatures by processing grooves on the surfaces of the probes to form sensitive areas, placing the sensitive areas in high-temperature environments, and analyzing the changes of the ultrasonic propagation speed in the sensitive areas of single-crystal fibers with ambient temperatures.

9. The said temperature measurement method according to claim 8, characterized in that the sensitive areas are 1-90 cm long with groove depths varying between 0.1 and 1 mm.

10. The said temperature measurement method according to claim 8, characterized in that the ultrasonic waves used for temperature measurement are P-waves or S-waves and preferred to be S-waves.

11. The said temperature measurement method according to claim 1, characterized in that the single-crystal fibers are high-melting-point oxide single-crystal fibers with melting points higher than 1800° C.

12. The said temperature measurement method according to claim 11, characterized in that the single-crystal fibers are Al.sub.2O.sub.3, YAG, LuAG, MgAl.sub.2O.sub.4, ZrO.sub.2, Lu.sub.2O.sub.3, Y.sub.2O.sub.3, Sc.sub.2O.sub.3, or HfO.sub.2.

13. The said temperature measurement method according to claim 1, characterized in that the diameters of the single-crystal fibers fall between 0.4 and 3 mm, and the lengths vary between 10 and 100 cm.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0044] FIG. 1 is the schematic diagram of the single-crystal fiber ultrasonic temperature sensor.

[0045] FIG. 2A shows the MgAl.sub.2O.sub.4 single-crystal fibers with different orientations (LHPG melting zon.

[0046] FIG. 2B shows the MgAl.sub.2O.sub.4 single-crystal fibers with different (MgAl.sub.2O.sub.4 single-crystal fibers with different orientations).

[0047] FIG. 2C shows the MgAl.sub.2O.sub.4 single-crystal fibers with different orientations (Zn:MgAl.sub.2O.sub.4 single-crystal fibers with different doping concentrations).

[0048] FIG. 2D shows the MgAl.sub.2O.sub.4 single-crystal fibers with different orientations (Zn, Cr:MgAl.sub.2O.sub.4 single-crystal fibers).

[0049] FIG. 3A shows the elastic anisotropy of the MgAl.sub.2O.sub.4 single-crystal fibers (adopts Young modulus).

[0050] FIG. 3B shows the elastic anisotropy of the MgAl.sub.2O.sub.4 single-crystal fibers (adopt shear modulus).

[0051] FIG. 3C shows the elastic anisotropy of the MgAl.sub.2O.sub.4 single-crystal fibers (adopt another shear modulus).

[0052] FIG. 4 shows the sensitivity of MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors with different orientations under the P-wave conditions in Test Example 1.

[0053] FIG. 5 shows the sensitivity of MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors with different orientations under the S-wave conditions in Test Example 1.

[0054] FIG. 6 shows the sensitivity of MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors upon different concentrations of Zn.sup.2+ doping in Test Example 1.

[0055] FIG. 7 shows the sensitivity of MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors upon 10 at % Zn.sup.2+ and 0.5 at % Cr.sup.3+ co-doping in Test Example 1.

DETAILED EMBODIMENTS

[0056] To clarify the purpose, the technical solution, and the advantages, the invention is further described as follows in combination with the specific embodiments. The embodiments set out here are used to explain the invention only, but not all.

Embodiment 1

[0057] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers, which uses single-crystal fibers upon crystal orientation optimization as the probes of ultrasonic temperature sensors, processes grooves on the surfaces of the probes to form sensitive areas, and measures temperatures by placing the sensitive areas in high-temperature environments and analyzing the changes of the ultrasonic propagation speed in the sensitive areas of single-crystal fibers with ambient temperatures.

[0058] The said single-crystal fibers upon crystal orientation optimization are [100] MgAl.sub.2O.sub.4 single-crystal fibers with a diameter of 0.5 mm and a length of 300 mm. The sensitive areas are 200 m long with a groove depth of 0.1 mm and use P-waves as sensing waves.

Embodiment 2

[0059] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 1, provided that:

[0060] the orientation of the MgAl.sub.2O.sub.4 single-crystal fibers is [110].

Embodiment 3

[0061] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 1, provided that:

[0062] the orientation of the MgAl.sub.2O.sub.4 single-crystal fibers is [111].

Embodiment 4

[0063] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 1, provided that:

[0064] the Embodiment uses S-waves as sensing waves and [100] MgAl.sub.2O.sub.4 single-crystal fibers with a diameter of 0.5 mm and a length of 300 mm as probes, the sensitive areas of which are 200 mm long with a groove depth of 0.1 mm.

Embodiment 5

[0065] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 4, provided that: the orientation of the MgAl.sub.2O.sub.4 single-crystal fibers is [110].

Embodiment 6

[0066] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 4, provided that: the orientation of the MgAl.sub.2O.sub.4 single-crystal fibers is [111].

Embodiment 7

[0067] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers, which uses single-crystal fibers having undergone crystal orientation optimization and doping modulation as the probes of ultrasonic temperature sensors, processes grooves on the surfaces of the probes to form sensitive areas, and measures temperatures by placing the sensitive areas in high-temperature environments and analyzing the changes of the ultrasonic propagation speed in the sensitive areas of single-crystal fibers with ambient temperatures.

[0068] The said single-crystal fibers having undergone crystal orientation optimization and doping modulation are [110] MgAl.sub.2O.sub.4 single-crystal fibers with a diameter of 0.5 mm and a length of 300 mm and upon 1 at % Zn.sup.2+ doping. The sensitive areas are 200 m long with a groove depth of 0.1 mm and use S-waves as sensing waves.

Embodiment 8

[0069] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 7, provided that: the doping concentration of Zn.sup.2+ is 5 at %.

Embodiment 9

[0070] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 7, provided that: the doping concentration of Zn.sup.2+ is 10 at %.

Embodiment 10

[0071] A high-sensitivity single-crystal fiber temperature measurement method based on the acoustic anisotropy and doping modulation of single-crystal fibers the same as the one said in Embodiment 7, provided that:

[0072] the Embodiment uses S-waves as sensing waves and [110] MgAl.sub.2O.sub.4 single-crystal fibers with a diameter of 0.5 mm and a length of 300 mm and upon 10 at % Zn.sup.2+ and 0.5 at % Cr.sup.3+ co-doping as probes, the sensitive areas of which are 200 mm long with a groove depth of 0.1 mm.

[0073] Test Case 1

[0074] The ultrasonic sensing characteristics of Embodiments 1-10 were tested. FIGS. 4, 5, 6, and 7 show the sensor performance of Embodiments 1-3, Embodiments 4-6, Embodiments 7-9, and Embodiment 10 respectively. Table 1 shows the unit sensitivity of Embodiments 1-10 at 1200° C.

TABLE-US-00001 TABLE 1 Unit sensitivity at No. 1200° C. (ns .Math. °C..sup.−1 .Math. m.sup.−1) Embodiment 1 15.01 Embodiment 2 14.91 Embodiment 3 14.81 Embodiment 4 31.91 Embodiment 5 41.86 Embodiment 6 36.79 Embodiment 7 47.89 Embodiment 8 52.02 Embodiment 9 59.30 Embodiment 10 67.49

[0075] As can be seen from Table 1, the sensitivity of single-crystal fiber ultrasonic temperature sensors is anisotropic in both P-wave and S-wave conditions, which is especially true under S-wave conditions, and the average sensitivity is higher. Therefore, the solution provided by the invention to improve the sensitivity of single-crystal fiber ultrasonic temperature sensors by reconditioning crystal orientations is feasible. Also, it is found that the sensitivity of MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors increases significantly with the doping concentrations of Zn.sup.2+ ions, presenting a performance far better than the pure-phase MgAl.sub.2O.sub.4 single-crystal fiber ultrasonic temperature sensors. Upon co-doping, the sensitivity of the sensors is further improved, evidencing that doping ion modification is a feasible way to improve the sensitivity of single-crystal fiber ultrasonic temperature sensors.