WO2016070700A1 - Nozzle and injection method - Google Patents

Abstract

A nozzle comprising a main body (10), said main body being a casing structure comprising a core pipe (11) and an external casing (12) each having an annular cross-section; the end of the core pipe and of the external casing have tapered cone-shaped structures which form a nozzle cap (13); the nozzle cap is provided with a gas injection port (14) in communication with the core pipe; and the sidewall of the external casing is provided with a plurality of spray holes (15, 16); during the gasification process, a gasification agent containing oxygen is supplied to the core pipe, water or an aqueous solution is supplied to the external casing, and the water or aqueous solution flows into a gasifier via the spray holes on the sidewall of the external casing and via the spray holes on the nozzle cap. The present invention allows for the integration of nozzle water-injection and cooling. This not only effectively provides the water necessary for a water gas reaction, but also effectively cools the nozzle. The extent to which the nozzle is overheating can be inferred from the change in water-injection pressure, and adjustments can thus be made during the gasification process. In injection method for the nozzle is also disclosed.

Description

Nozzle and injection method

The present application claims priority to Chinese Patent Application No. 2014-1223634.2, entitled "A Nozzle and Gasification Method", filed on November 6, 2014, the entire contents of which is incorporated herein by reference. .

Technical field

The present invention relates to the field of underground coal gasification, and more particularly to a nozzle and an injection method.

Background technique

Underground coal gasification technology is an emerging coal chemical technology. The injection point retreat technology has received wide attention because of its good controllability and effective reduction of the number of boreholes. In the process of coal gasification by the technology, an oxygen-containing gas is injected into the gasification passage of the coal seam through the gas injection pipe, and the oxygen-containing gas is ejected from the nozzle of the gas injection pipe to react with the surrounding coal seam, accompanied by high heat generation. Influenced by factors such as gasifier pressure, oxygen concentration around the nozzle, and ash slag blocking before the nozzle, it is easy to cause the gas injection pipe and nozzle to melt or damage, thereby affecting the continuity and stability of the gasification process.

Chinese Patent No. 201420299991.3 discloses a nozzle for underground coal gasification, wherein the nozzle comprises a nozzle body, a main air outlet hole is formed in the nozzle body, and a lateral air outlet hole communicating with the main air outlet hole is further formed on the side wall. Although it sprays the gasifying agent from the lateral air outlet, it can only prevent the ash after the combustion of the coal layer in the gasification process from adhering to the side of the nozzle, and the high heat problem of the nozzle itself cannot be solved.

Summary of the invention

The technical problem to be solved by the present invention is to provide a nozzle which can solve the high heat of the nozzle itself and avoid nozzle damage.

Another technical problem to be solved by the present invention is to provide a method for underground injection of coal.

In order to achieve the above object, the nozzle of the present invention comprises a nozzle body, which is a sleeve structure, comprising a central tube and an outer ring sleeve having a ring-shaped cross section, and a central tube The end of the outer ring sleeve adopts a tapered tapered structure to form a nozzle top cap, and the nozzle top cap is provided with a gas injection port communicating with the central pipe, and the outer ring casing is provided with a plurality of water sprays on the side wall hole.

Preferably, the nozzle further comprises a water injection pipe and a gas injection pipe, wherein the water injection pipe and the outer ring sleeve are in communication, and the gas injection pipe and the central pipe are in communication.

Preferably, the water injection pipe is provided with a water pressure detecting device.

Preferably, the water injection pipe is connected through a connecting sleeve and an outer ring sleeve, and the gas injection pipe communicates with the central pipe through a gap of the connecting sleeve.

Preferably, the nozzle further comprises at least one thermocouple wire, and the temperature measuring point of the thermocouple wire is disposed on the center tube.

Preferably, the plurality of water spray holes are provided on the outer circumference of the gas injection port on the top hat of the nozzle.

The method for injecting according to the present invention comprises: introducing a oxygenating agent into the central tube during the gasification process, and introducing water or an aqueous solution into the outer ring casing, the water or the aqueous solution being sprayed from the side wall of the outer ring casing The water hole enters the gasifier.

Preferably, during the gasification process, when the nozzle temperature is detected to exceed 100 ° C, the change in the gas composition of the underground gasifier outlet is further detected.

If the gas composition drops by less than 10%, increase the amount of water injected.

If the gas component drops by 10% or more, the nozzle position is moved backward.

Preferably, the increased water injection amount is from 10% to 30% of the normal water injection amount.

Preferably, the method further comprises: presetting a normal pressure value and an abnormal pressure value; during the gasification process, the water or the aqueous solution is transported to the outer ring casing through the water injection pipe, and the actual pressure value of the water in the water injection pipe is detected. When the actual pressure value reaches the abnormal pressure value, increase the water injection amount by 10%-30% and/or move the nozzle position backward until the actual pressure value returns to the normal pressure value.

Preferably, the method further comprises: the abnormal pressure value is 110% of a normal pressure value.

Preferably, the method further comprises: the amount of water injected into the gasifier may fluctuate within ±30% of the water demand V of the gasifier.

The invention has the beneficial effects that: the invention adopts the nozzle structure of the central tube and the outer ring sleeve with holes, so that the water injection and the cooling are integrated, and the water gas is effectively provided. The water required for the reaction, while the water can effectively remove heat, cool the nozzle and increase the life of the nozzle. In addition, by simultaneously detecting the temperature change at the nozzle, the change in the gas composition, and the change in the water pressure in the water injection pipe, the heat of the nozzle is estimated, and the gasification process is adjusted in real time according to the heating condition, so that the nozzle can be more effectively protected.

DRAWINGS

The drawings are intended to provide a further understanding of the invention, and are intended to be a In the drawing:

Figure 1 is a schematic view showing the structure of a first embodiment of the nozzle of the present invention;

Figure 2 is a schematic view showing the structure of the injection tube and the nozzle body of the first embodiment of the nozzle of the present invention;

3 is a schematic structural view of a nozzle top cap of a first embodiment of the nozzle of the present invention;

Figure 4 is a schematic view showing the structure of the injection tube and the nozzle body of the second embodiment and the third embodiment of the nozzle of the present invention;

Figure 5 is a schematic view showing the structure of the nozzle top cap of the second embodiment and the third embodiment of the nozzle of the present invention;

Figure 6 is a schematic structural view of a fourth embodiment of the nozzle of the present invention;

Figure 7 is a schematic view showing the structure of the injection pipe and the nozzle body of the fourth embodiment of the nozzle of the present invention;

Description of the reference numerals

10 nozzle body 11 center tube 12 outer ring sleeve

13 nozzle top cap 14 gas injection port 15, 16 water spray hole

17 Temperature measurement point 20 Injection tube 21 Air injection tube

22 Water injection pipe 23 Thermocouple wire 24 Water pressure detecting device

25 Connection sleeve 26 Connection tube.

detailed description

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative and not restrictive.

In the present invention, the orientation words such as "up, down, left, and right" as used generally refer to the directions shown in the drawings of the specification, unless otherwise stated.

Referring to FIGS. 1 and 2, the nozzle of the present invention includes a nozzle body 10 which is a sleeve structure including a central tube 11 and an outer ring sleeve 12 having a ring-shaped cross section, and a central tube 11 and an outer ring sleeve 12 The tip end adopts a tapered tapered structure to form a nozzle top cap 13. The nozzle top cap 13 is provided with a gas injection port 14 communicating with the central pipe 11, and the outer ring casing 12 is provided with a plurality of water spray holes on the side wall thereof. 16.

The central tube 11 is an oxygen-containing agent channel, and the outer ring sleeve 12 is a cooling water channel. As shown in FIG. 3, the gas injection port 14 is disposed at a position of the nozzle top cap 13 facing the central tube nozzle.

In addition, a plurality of water spray holes 15 may be provided on the outer circumference of the gas injection port 14 of the nozzle top cap 13. Although a plurality of water spray holes 16 are provided on the side wall of the outer ring sleeve 12, the present invention can be realized. The object of the invention is to provide a plurality of water spray holes 15 on the nozzle top cap 13, which can further improve the cooling effect of the present invention.

The nozzle further includes an injection tube 20 connected to the nozzle body 10 by welding or threading, and the injection tube 20 is provided with a gas injection pipe 21, a water injection pipe 22 and at least one thermocouple wire 23. The water injection pipe 22 is connected to the outer ring pipe sleeve 12 through a connecting sleeve 25 for conveying water or an aqueous solution (aqueous solution refers to an aqueous liquid, hereinafter collectively referred to as "water") required for gasification and cooling to the outer ring pipe sleeve 12 The water is ejected through the water spray hole 16 on the side wall of the outer ring sleeve 12 and the water spray hole 15 on the nozzle top cap 13. The gas injection pipe 21 is connected to the center pipe 11 through a slit of the joint sleeve 25 for conveying an oxygen-containing gasifying agent.

The water injection pipe 22 is provided with a water pressure detecting device 24, and the water pressure detecting device 24 transmits the water pressure value in the water injection pipe 22 to the ground water pressure control system and/or the pressure display device. One end of the thermocouple wire 23 in the injection pipe 20 is connected to the center pipe 11 on the nozzle body 13, forming a temperature measuring point 17, and the other end is connected to a temperature control system and/or a temperature display device on the ground.

It should be noted that the number of water spray holes provided on the nozzle top cap 13 can be varied. Preferably, the number of water spray holes is 6-12, and the number of spray holes disposed on the side wall of the outer ring sleeve 12 can be Variation, preferably the number of water spray holes is 4 to 6 columns, nozzle top cap 13 The distribution of the water spray holes on the side walls of the upper and outer ring sleeves 12 may be uniformly distributed or unevenly distributed, preferably in a uniform distribution manner.

In the gasification of the coal seam, the oxygen-containing gas is injected into the gasification furnace through the gas injection pipe 21, and water is injected into the outer ring casing 12 through the water injection pipe 22, which serves the purpose of cooling the nozzle on the one hand, and the water passage on the other hand. The outer ring sleeve 12 and the spray holes 15, 16 of the nozzle top cap 13 enter the gasifier to complete the water gas reaction.

The water injected into the gasifier can be controlled according to the water demand of the gasifier. The calculation formula of the water demand V of the gasifier is as follows:

V=MC×α-9 (H-H coal)

MC - the amount of carbon in the amount of coal burned

H out - hydrogen content in the export gas

H coal - hydrogen content in coal burning

α—The amount of water previously injected into the gasifier can be fluctuated within ±30% of the water demand of the gasifier.

During the process of water injection into the gasifier, the water pressure detecting device 24 detects the pressure in the water injection pipe 22. Under normal circumstances, the pressure in the water injection pipe 22 does not change when the conditions in the gasification furnace do not change greatly. Abruptly changing, but if the temperature outside the nozzle is greatly increased, the water ejected from the water spout will soon become steam, the volume will expand, and the pressure inside the water injection pipe 22 will rise, and the water pressure detecting device 24 will inject water. The pressure signal within the tube is transmitted to the ground control device and/or the display device.

In the gasification process, if the thermocouple 23 detects that the temperature at the nozzle exceeds 100 ° C, the change of the gas component of the underground gasifier outlet is further detected. If the gas component falls less than 10%, the water injection is increased, and the water injection is increased. The water injection amount is 10%-30% of the normal water injection amount; if the gas composition drops by 10% or more, the nozzle position is moved backward.

During the gasification process, water or an aqueous solution is transported to the outer ring casing through the water injection pipe. When the actual pressure value of the water or the aqueous solution in the water injection pipe exceeds 110% of the normal pressure value, the water injection amount is increased to 110% of the normal water injection amount. -130% and / or move the nozzle position backwards until the actual pressure value returns to the normal pressure value.

Specific embodiment 1

As shown in FIG. 2 and FIG. 3, in the present embodiment, the outer ring sleeve 12 and the water injection pipe 22 are connected by a connecting sleeve 25, and the connecting sleeve 25 is composed of three connecting pipes 26 having an angle of 120°, through which the connecting pipe is passed. 26 is connected to the outer ring sleeve 12. There are six water spray holes on the outer circumference of the nozzle top cap 13, and four rows of water spray holes 6 are arranged on the side wall of the outer ring sleeve 12, and each column is arranged at a 90° pitch.

Specific embodiment 2

As shown in FIG. 4 and FIG. 5, in the present embodiment, the outer ring sleeve 12 and the water injection pipe 22 are connected by a connecting sleeve 25, and the connecting sleeve 25 is composed of four connecting pipes 26 having an angle of 90°, through which the connection is made. The tube 26 is connected to the outer ring sleeve 12. There are 12 water spray holes on the outer circumference of the nozzle top cap 13, and six rows of water spray holes 6 are arranged on the side wall of the outer ring sleeve 12, and each column is arranged at a 60° pitch.

Concrete embodiment 3

As shown in FIG. 4 and FIG. 5, in the present embodiment, the outer ring sleeve 12 and the water injection pipe 22 are connected by a connecting sleeve 25, and the connecting sleeve 25 is composed of four connecting pipes 26 having an angle of 90°, through which the connection is made. The tube 26 is connected to the outer ring sleeve 12. There are 12 water spray holes on the outer circumference of the nozzle top cap 13, and six rows of water spray holes 6 are arranged on the side wall of the outer ring sleeve 12, and each column is arranged at a 60° pitch.

In the gasification process, the water injection pressure is 0.5 MPa, the normal fluctuation is 5%, that is, the pressure is within 0.5±0.025 MPa. If the pressure fluctuation of the water injection exceeds 0.05 MPa, it is considered that the front nozzle is affected by the high temperature and needs to be increased by 10 %-30% of the flow of water injection or moving the nozzle position backwards until the pressure returns to normal.

Concrete embodiment 4

As shown in FIG. 6 and FIG. 7, in the present embodiment, the outer ring sleeve 12 and the water injection pipe 22 are connected by a connecting sleeve 25, which is a tapered steel sleeve at an angle of 60° to the nozzle cross section. In the middle of the connecting sleeve 25, there are six water injection holes communicating with the outer ring sleeve 12 of the nozzle, and the gap of the connecting sleeve 25 can pass through the injected gasifying agent. There are six water spray holes on the outer circumference of the nozzle top cap 13, and four rows of water spray holes 6 are arranged on the side wall of the outer ring sleeve 12, and each column is arranged at a 90° pitch.

In the gasification process, the water injection pressure is 1.5 MPa, and the normal fluctuation is 8%, that is, the pressure. Within 1.5 ± 0.12 MPa, if the pressure fluctuation of the water injection exceeds 0.15 MPa, it is considered that the front nozzle is affected by the high temperature, and it is necessary to increase the flow rate of the water injection by 10% to 30% or to move the nozzle position backward until the pressure returns to normal. The preferred 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 specific details of the embodiments described above, and various modifications may be made to the technical solutions of the present invention within the scope of the technical idea of the present invention. These simple variations are within the scope of the invention.

It should be further noted that the specific technical features described in the above specific embodiments may be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention has various possibilities. The combination method will not be described separately.

In addition, any combination of various embodiments of the invention may be made as long as it does not deviate from the idea of the invention, and it should be regarded as the disclosure of the invention.

Claims (11)

A nozzle comprising a nozzle body, wherein the nozzle body is a sleeve structure comprising a central tube and an outer ring sleeve having an annular cross section, and the ends of the central tube and the outer ring sleeve are tapered. The structure forms a nozzle top cap, and the nozzle top cap is provided with a gas injection port communicating with the central pipe, and a plurality of water spray holes are arranged on the side wall of the outer ring sleeve. The nozzle according to claim 1, wherein said nozzle further comprises a water injection pipe and a gas injection pipe, said water injection pipe being in communication with said outer ring casing, said gas injection pipe being in communication with said center pipe. The nozzle according to claim 2, wherein said water injection pipe is provided with a water pressure detecting means. The nozzle according to claim 2, wherein said water injection pipe is in communication with said outer ring sleeve through said connecting sleeve, said gas injection pipe being in communication with said central pipe through a slit of said connecting sleeve. The nozzle of claim 1 wherein said nozzle further comprises at least one thermocouple wire, said temperature measuring point of said thermocouple wire being disposed on said central tube. The nozzle according to claim 1, wherein a plurality of water spray holes are provided on an outer circumference of the gas injection port on the nozzle top cap. An injection method having the nozzle of any of claims 1-6, characterized in that: In the gasification process, an oxygenating agent is introduced into the central pipe, and water or an aqueous solution is introduced into the outer ring casing, and the water or the aqueous solution enters the gasifier from the water spray hole. The injection method according to claim 7, wherein during the gasification process, when the nozzle temperature exceeds 100 ° C, If the gas composition at the outlet of the underground gasifier drops by less than 10%, the water injection amount is increased; If the gas composition at the outlet of the underground gasifier drops by 10% or more, the nozzle position is moved backward. The injection method according to claim 8, wherein the increased water injection amount is 10% to 30% of the normal water injection amount. The method of injecting according to claim 7, comprising: During the gasification process, water or an aqueous solution is transported to the outer ring casing through the water injection pipe. When the actual pressure value of the water or the aqueous solution in the water injection pipe exceeds 110% of the normal pressure value, the water injection amount is increased to 110% of the normal water injection amount. -130% and / or move the nozzle position backwards until the actual pressure value returns to the normal pressure value. The injection method according to claim 7, wherein the amount of water injected into the gasification furnace is within ±30% of the water demand of the gasification furnace.

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