Zirconium oxide ceramic supersonic nozzle structure for underground coal gasification

Abstract

The utility model relates to the field of nozzles, in particular to a zirconia ceramic supersonic nozzle structure for underground coal gasification, which comprises a nozzle component, fixing threads connected onto the nozzle component, a sealing component movably connected inside the nozzle component and two sealing grooves arranged on the outer surface of the nozzle component. The nozzle assembly comprises a buffer body movably connected to the sealing assembly and a first compression section connected to the buffer body. The maintenance cost is reduced by arranging the sealing assembly with the adjustable diameter, meanwhile, the sealing ring and the sealing structure are matched with each other to conduct isolation sealing, so that the airtightness of the whole nozzle structure is improved, gas leakage is avoided, the sealing structure is rapidly disassembled through the arrangement of the pressing nut, and the sealing structure is convenient to disassemble. The use convenience of the whole nozzle structure is further improved, and the air tightness of the device is ensured through the arrangement of the fixing threads and the two sealing grooves, so that it is ensured that air cannot leak from the surface of the buffer body.

Description

Technical Field

[0001] This utility model relates to the field of nozzles, and more particularly to a zirconia ceramic supersonic nozzle structure for underground coal gasification. Background Technology

[0002] To ignite an underground coal seam and initiate the underground coal gasification process, the coal seam needs to be heated to its ignition point in the presence of an oxidant such as air, oxygen-enriched air, or pure oxygen. The ignition points of various types of coal, such as lignite, bituminous coal, anthracite, and coke, are generally 400-700℃. Once the oxidant is sufficient and the temperature reaches the ignition point, external heating is no longer required; the coal seam can sustain the entire combustion / gasification process through its own combustion. Therefore, in the ignition stage of the underground coal gasification process, igniting and sustaining the combustion of the underground coal seam requires fuel, heat, and an oxidant. The coal itself can serve as fuel, the initial heat usually comes from external sources, including the heat generated by the combustion of externally added ignition fuel, and the oxidant, such as air or oxygen, is also typically supplied externally.

[0003] Traditional nozzle structures often have a fixed, integrated throat. When the performance of the components deteriorates due to wear, corrosion, or changes in operating conditions, the entire nozzle structure needs to be disassembled and replaced. This complicates the maintenance process of the entire nozzle structure and significantly increases the cost of spare parts. Utility Model Content

[0004] To overcome the problem that existing nozzles inevitably require replacement of the entire nozzle structure when a component wears or corrodes during use, which is due to the integrated internal structure of the nozzle.

[0005] The technical solution of this utility model is: a zirconia ceramic supersonic nozzle structure for underground coal gasification, including a nozzle assembly, a fixing thread connected to the nozzle assembly, a sealing assembly movably connected inside the nozzle assembly, and two sealing grooves opened on the outer surface of the nozzle assembly.

[0006] The nozzle assembly includes a buffer body movably connected to a sealing assembly, a first compression section connected to the buffer body, a second compression section connected to the first compression section, and an expansion section connected to the second compression section.

[0007] Preferably, the sealing assembly includes a zirconia ceramic supersonic nozzle movably connected to the expansion section, a sealing structure connected to the zirconia ceramic supersonic nozzle, a sealing ring formed on the inner wall of the expansion section, and a clamping nut clearance-fitted to the expansion section.

[0008] Preferably, the expansion section has a narrow throat on the side near the second compression section, and a nozzle outlet on the side of the expansion section away from the second compression section.

[0009] Preferably, the first compression section is cylindrical, and both the second compression section and the expansion section are conical.

[0010] Preferably, the diameter of the second compression section gradually decreases along the direction of the nozzle outlet, while the diameter of the expansion section gradually increases along the direction of the nozzle outlet.

[0011] Preferably, the ratio of the diameter of the first compression section to the minimum diameter of the second compression section to the maximum diameter of the expansion section is set to 50:12:13.5.

[0012] Preferably, the longitudinal length of the first compression section: the longitudinal length of the second compression section: the longitudinal length of the expansion section is set to 42:64:11.

[0013] The beneficial effects of this utility model are:

[0014] This invention reduces maintenance costs by setting an adjustable diameter sealing component. At the same time, it uses the sealing ring and sealing structure to cooperate to isolate and seal, thereby improving the airtightness of the entire nozzle structure and preventing gas leakage. Furthermore, the setting of the clamping nut enables quick disassembly of the sealing structure, further improving the ease of use of the entire nozzle structure. The setting of the fixing thread and two sealing grooves ensures the airtightness of the device, so as to ensure that gas does not leak from the surface of the buffer body.

[0015] This invention installs a continuous tubing on a first compression section, allowing gas passing through the tubing to undergo initial compression within the first compression section and further compression within a second compression section. This causes the gas to accelerate and exit at the expansion section, achieving supersonic speeds. Under high pressure, the gas flows from the first compression section towards the nozzle outlet on the expansion section. In this stage, the gas movement follows the principle that "fluid velocity is higher at smaller cross-sections and lower at larger cross-sections" in a pipe, thus the gas continuously accelerates. When it reaches the narrow throat, the velocity exceeds the speed of sound. However, transonic fluids do not follow the principle of "higher velocity at smaller cross-sections and lower velocity at larger cross-sections"; instead, the opposite is true: the larger the cross-section, the faster the velocity. At the maximum diameter of the expansion section, the gas velocity is further accelerated to generate thrust, thereby achieving supersonic jetting with this supersonic nozzle structure. Attached Figure Description

[0016] Figure 1 The diagram shown is a cross-sectional view of the supersonic nozzle structure of this utility model.

[0017] Figure 2 The diagram shown is a cross-sectional view of the expansion section of the supersonic nozzle structure of this utility model.

[0018] Figure 3 The diagram shown is a schematic representation of the expansion section of the supersonic nozzle structure of this invention.

[0019] Explanation of reference numerals in the attached drawings: 1. Fixed thread; 2. Buffer body; 3. Sealing groove; 4. Narrow throat; 5. Nozzle outlet; 6. First compression section; 7. Second compression section; 8. Expansion section; 9. Compression nut; 10. Zirconia ceramic supersonic nozzle; 11. Sealing ring; 12. Sealing structure. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] A zirconia ceramic supersonic nozzle structure for underground coal gasification, based on Figures 1-3 As shown, it includes a nozzle assembly, a fixing thread 1 connected to the nozzle assembly, a sealing assembly movably connected inside the nozzle assembly, and two sealing grooves 3 formed on the outer surface of the nozzle assembly.

[0022] The sealing assembly includes a zirconia ceramic supersonic nozzle 10 movably connected to the nozzle assembly, a sealing structure 12 connected to the zirconia ceramic supersonic nozzle 10, a sealing ring 11 formed on the inner wall of the nozzle assembly, and a clamping nut 9 clearance-fitted to the nozzle assembly.

[0023] according to Figures 1-2 As shown, the nozzle assembly includes a buffer body 2 connected to a fixed thread 1, a first compression section 6 connected to the buffer body 2, a second compression section 7 connected to the first compression section 6, and an expansion section 8 connected to the second compression section 7.

[0024] It should be noted that by installing the coiled tubing on the first compression section 6, the gas passing through the coiled tubing can be compressed once inside the first compression section 6 and then compressed again inside the second compression section 7, so that the gas is accelerated and ejected at the expansion section 8, thereby achieving a supersonic state.

[0025] according to Figure 2 As shown, a narrow throat 4 is provided on the side of the expansion section 8 near the second compression section 7, and a nozzle outlet 5 is provided on the side of the expansion section 8 away from the second compression section 7.

[0026] It should be noted that under high pressure, the airflow moves from the first compression section 6 towards the nozzle outlet 5 on the expansion section 8. In this stage, the gas movement follows the principle that "when a fluid moves in a pipe, the velocity is higher where the cross-section is smaller and lower where the cross-section is larger." Therefore, the airflow continuously accelerates, and when it reaches the narrow throat 4, the velocity exceeds the speed of sound. However, transonic fluids do not follow the principle of "higher velocity at smaller cross-sections and lower velocity at larger cross-sections"; rather, the opposite is true: the larger the cross-section, the faster the velocity. At the maximum diameter of the expansion section 8, the airflow velocity is further accelerated to generate thrust.

[0027] according to Figure 1 As shown, the first compression section 6 is cylindrical, while the second compression section 7 and the expansion section 8 are both conical.

[0028] It should be noted that a gap is provided between the zirconia ceramic supersonic nozzle 10 and the buffer body 2, and the gap is set to 0.1-0.3cm. The expansion section of the zirconia ceramic supersonic nozzle 10 is set as a logarithmic spiral curve, and the radius of curvature varies with the axial distance according to R(x)=R0·exp(kx) (k=0.02-0.05).

[0029] according to Figures 1-2 As shown, the diameter of the second compression section 7 gradually decreases along the direction of the nozzle outlet 5, while the diameter of the expansion section 8 gradually increases along the direction of the nozzle outlet 5.

[0030] according to Figures 1-2 As shown, the ratio of the diameter of the first compression section 6 to the minimum diameter of the second compression section 7 to the maximum diameter of the expansion section 8 is set to 50:12:13.5.

[0031] according to Figures 1-2 As shown, the longitudinal length of the first compression section 6: the longitudinal length of the second compression section 7: the longitudinal length of the expansion section 8 are set to 42:64:11.

[0032] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A zirconia ceramic ultrasonic nozzle structure for underground coal gasification, characterized in that: It includes a nozzle assembly, a fixed thread (1) connected to the nozzle assembly, a sealing assembly movably connected inside the nozzle assembly, and two sealing grooves (3) formed on the outer surface of the nozzle assembly. The sealing assembly includes a zirconia ceramic supersonic nozzle (10) movably connected to the nozzle assembly, a sealing structure (12) connected to the zirconia ceramic supersonic nozzle (10), a sealing ring (11) formed on the inner wall of the nozzle assembly, and a clamping nut (9) clearance-fitted to the nozzle assembly.

2. The zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 1, characterized in that: The nozzle assembly includes a buffer body (2) connected to a fixed thread (1), a first compression section (6) connected to the buffer body (2), a second compression section (7) connected to the first compression section (6), and an expansion section (8) connected to the second compression section (7).

3. A zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 2, characterized in that: The expansion section (8) has a narrow throat (4) on the side close to the second compression section (7), and a nozzle outlet (5) is provided on the side of the expansion section (8) away from the second compression section (7).

4. The zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 2, characterized in that: The first compression section (6) is cylindrical, and the second compression section (7) and the expansion section (8) are both conical.

5. The zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 3, characterized in that: The diameter of the second compression section (7) gradually decreases along the direction of the nozzle outlet (5), and the diameter of the expansion section (8) gradually increases along the direction of the nozzle outlet (5).

6. The zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 2, characterized in that: The diameter of the first compression section (6): the minimum diameter of the second compression section (7): the maximum diameter of the expansion section (8) are set to 50:12:13.

5.

7. The zirconia ceramic supersonic nozzle structure for underground coal gasification according to claim 2, characterized in that: The longitudinal length of the first compression segment (6) is set as follows: the longitudinal length of the second compression segment (7) is set as follows: the longitudinal length of the expansion segment (8) is set as follows: 42:64:11.

Images