Coal water slurry nozzle capable of synchronously increasing coal slurry pressure difference and central oxygen flow

Abstract

The invention discloses a coal water slurry nozzle capable of synchronously increasing coal slurry pressure difference and central oxygen flow, which comprises a central oxygen nozzle, a coal water slurry nozzle and an outer epoxy nozzle which are nested layer by layer from the axis side to the outer side of a shaft, the central oxygen spraying channel located in the central oxygen nozzle can be communicated with the coal water slurry annular space located between the central oxygen nozzle and the coal water slurry nozzle through the through hole, and the coal slurry pressure difference and the central oxygen flow can be synchronously increased.

Description

[Technical field]

[0001] The present invention relates to the technical field of coal chemical industry, in particular to the technical field of water-coal slurry fluidized-bed coal gasification. [Background technology]

[0002] Coal gasification technology is a technology that uses gasification agents to react with coal to generate clean syngas (a mixture of CO2, CO and H2) at a certain temperature and pressure. Coal gasification technology is the key to achieving clean utilization of coal and is the leading technology for coal-based chemicals (such as synthetic ammonia, methanol and olefins), integrated gasification combined cycle power generation (IGCC), coal-based polygeneration and direct reduction ironmaking systems.

[0003] Entrained-bed coal gasification technology is one of the most advanced clean coal technologies in the world and is known as green coal technology. The process burner is the core equipment of the entrained-bed coal gasification technology, which determines the stability and economy of the operation of the entrained-bed gasifier. Based on the form of the raw materials used, the entrained-bed coal gasification technology is divided into pulverized coal technology and water-coal slurry technology. The water-coal slurry process burner is distinguished by the coal slurry and oxygen channels. The current mainstream technologies are three-channel and four-channel; based on the mixing method of coal slurry and oxygen, it is divided into pre-film type and pre-mixed type.

[0004] Compared with the premixed process burner, the water-coal slurry nozzle inside the pre-film process burner often has the problem of relatively low coal slurry pressure difference and small central oxygen flow rate relative to the design flow rate (generally at the lower limit of the design flow rate) during operation. Although such operating parameters are not the best state for gasification operation, the industry has not found a solution to simultaneously improve the coal slurry pressure difference and central oxygen flow rate. [Summary of the invention]

[0005] The purpose of the present invention is to solve the problems in the prior art and to propose a water-coal slurry nozzle that can synchronously increase the coal slurry pressure difference and the central oxygen flow rate, so that the coal slurry pressure difference and the central oxygen flow rate can be synchronously increased.

[0006] To achieve the above-mentioned purpose, the present invention proposes a water-coal slurry nozzle that can synchronously increase the coal slurry pressure difference and the central oxygen flow rate, including a central oxygen nozzle, a water-coal slurry nozzle and an outer annular oxygen nozzle that are nested layer by layer from the axial side to the outer side of the axis, and a through hole is provided on the central oxygen nozzle. The through hole can connect the central oxygen spray channel located inside the central oxygen nozzle and the water-coal slurry annular gap located between the central oxygen nozzle and the water-coal slurry nozzle.

[0007] Preferably, the outlet ends of the central oxygen nozzle, water-coal slurry nozzle and outer epoxy nozzle are respectively provided with a central oxygen nozzle body cone section, a water-coal slurry nozzle body cone section and an outer epoxy nozzle body cone section which gradually narrow outwards, and the through hole is arranged at the central oxygen nozzle body cone section.

[0008] Preferably, the cross-sectional area of ​​the through hole located on the inner surface of the tube wall of the central oxygen nozzle is smaller than the cross-sectional area of ​​the through hole located on the outer surface of the tube wall of the central oxygen nozzle.

[0009] Preferably, the axis of the through hole is a straight line, an arc line or a spiral line, wherein the optimal solution for the axis of the through hole is a spiral line.

[0010] Preferably, the cross section of the through hole is circular and the hole wall surface is smooth.

[0011] Preferably, the number of the through holes is not less than 2 and they are evenly distributed along the circumference.

[0012] Furthermore, the number of the through holes is calculated according to formula (a), formula (b) and formula (c);

[0013]

[0014] In the formula, Q1 is the central oxygen flow rate of the nozzle before the hole is opened, S1 is the central oxygen flow cross-sectional area of ​​the nozzle before the hole is opened, Q0 is the oxygen flow rate per unit area of ​​the nozzle before the hole is opened, Q2 is the increased oxygen flow rate of the nozzle after the hole is opened, S2 is the increased flow cross-sectional area of ​​the nozzle after the hole is opened, n is the number of through holes set, and S0 is the minimum flow cross-sectional area of ​​the through holes.

[0015] Preferably, a one-way switch is installed in the through hole, which only allows the fluid to flow out from the central oxygen nozzle to the water-coal slurry annulus.

[0016] Preferably, it also includes a circulating cooling structure that can utilize circulating cooling water to cool the water-coal slurry nozzle.

[0017] Furthermore, the circulating cooling structure is a circulating cooling water coil arranged around the outer circumference of the external epoxy nozzle, a circulating cooling water jacket arranged in the wall of the external epoxy nozzle, or a circulating cooling water double-cone half jacket arranged in the wall of the external epoxy nozzle. The circulating cooling water flow channel of the circulating cooling water jacket has a uniform diameter throughout the body, and the circulating cooling water flow channel of the circulating cooling water double-cone half jacket is provided with expansion structures at the water inlet and the water outlet respectively, and the circulating cooling water flow channel is spiral.

[0018] Beneficial effects of the present invention:

[0019] 1) A water-coal slurry nozzle is formed by using a central oxygen nozzle, a water-coal slurry nozzle and an outer ring oxygen nozzle which are nested layer by layer from the axis side to the axis outside, and a plurality of through holes are added at the cone section of the central oxygen nozzle body of the central oxygen nozzle. Each through hole can be used to form an additional channel between the water-coal slurry annular gap (located between the central oxygen nozzle and the water-coal slurry nozzle) and the central oxygen spray channel (located inside the central oxygen nozzle) for air flow in and out, thereby increasing the flow cross-sectional area of ​​the central oxygen and improving the central oxygen flow rate; at the same time, since the high-pressure oxygen can form resistance to the flow of the coal slurry after entering the coal slurry channel, the coal slurry pressure difference can be effectively increased; on the other hand, this also allows the water-coal slurry to be premixed with the entering high-pressure oxygen in advance, which is more conducive to the atomization of the water-coal slurry, so that the gasification operation can reach the best state;

[0020] 2) By setting the axis line of the through hole to a straight line, an arc line or a spiral line, and making the cross-sectional area of ​​the through hole located on the inner surface of the tube wall of the central oxygen nozzle smaller than the cross-sectional area of ​​the through hole located on the outer surface of the tube wall of the central oxygen nozzle, this special shape and cross-sectional design can be used to make the high-pressure oxygen entering the coal slurry channel evenly distributed and dispersed, thereby mixing more evenly with the water-coal slurry, effectively improving the atomization effect of the water-coal slurry;

[0021] 3) By installing a one-way switch in the through hole, the one-way switch can be used to only allow the fluid to flow out from the central oxygen nozzle to the water-coal slurry annulus, effectively avoiding the phenomenon of the fluid flowing in the opposite direction to the design direction.

[0022] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0023] Figure 1 is a front view of the first embodiment;

[0024] Figure 2 is a bottom view of the first embodiment;

[0025] Figure 3 yes Figure 2 AA section view;

[0026] Figure 4 yes Figure 3 An enlarged schematic diagram of point B;

[0027] Figure 5 yes Figure 3 CC section view;

[0028] Figure 6 yes Figure 5 An enlarged schematic diagram of D;

[0029] Figure 7 is a front view of the second embodiment;

[0030] Figure 8 is a bottom view of the second embodiment;

[0031] Fig. 9 yes Figure 8 EE section view

[0032] Fig.10 yes Fig. 9 FF cross-sectional view

[0033] Fig.11 is a front view of Embodiment 3;

[0034] Fig.12 is a bottom view of the third embodiment;

[0035] Fig.13 yes Fig.12 GG section view

[0036] Fig.14 yes Fig.13 HH section view

[0037] Fig.15 It is a simplified layout diagram of the through hole when the axis line is a straight line;

[0038] Fig.16 It is a simplified layout diagram of the through hole when the axis line is a spiral line;

[0039] Fig.17 This is a simplified layout diagram of the through hole when the axis line is an arc line.

[0040] In the figure: 1-central oxygen nozzle, 2-water-coal slurry nozzle, 3-external epoxy nozzle, 4-central oxygen spray channel, 5-water-coal slurry annulus, 6-external epoxy annulus, 7-through hole, 8-circulating cooling structure. [Specific implementation method]

[0041] Embodiment 1:

[0042] See also Figures 1 to 6 The water-coal slurry nozzle of the present invention can synchronously improve the coal slurry pressure difference and the central oxygen flow rate, including a central oxygen nozzle 1, a water-coal slurry nozzle 2 and an outer annular oxygen nozzle 3 that are nested layer by layer from the axial side to the outer side of the axis, and a through hole 7 is provided on the central oxygen nozzle 1. The through hole 7 can connect the central oxygen spray channel 4 located inside the central oxygen nozzle 1 and the water-coal slurry annular gap 5 located between the central oxygen nozzle 1 and the water-coal slurry nozzle 2.

[0043] The outlet ends of the central oxygen nozzle 1, the water-coal slurry nozzle 2 and the outer epoxy nozzle 3 are respectively provided with a central oxygen nozzle body cone section, a water-coal slurry nozzle body cone section and an outer epoxy nozzle body cone section which gradually narrow outwards, and the through hole 7 is arranged at the central oxygen nozzle body cone section.

[0044] The cross-sectional area of ​​the through hole 7 located on the inner surface of the tube wall of the central oxygen nozzle 1 is smaller than the cross-sectional area of ​​the through hole 7 located on the outer surface of the tube wall of the central oxygen nozzle 1 .

[0045] The axis of the through hole 7 is a straight line (for specific styles, please refer to Fig.15 ).

[0046] The cross section of the through hole 7 is circular and the hole wall surface is smooth.

[0047] The number of the through holes 7 is 12 and they are evenly distributed along the circumference.

[0048] In actual application, the number of through holes 7 can be calculated according to formula a, formula b and formula c (that is, the number of through holes 7 is determined by the designed increased flow rate and the flow area of ​​the through holes 7);

[0049]

[0050] In the formula, Q1 is the central oxygen flow rate of the nozzle before the hole is opened, S1 is the central oxygen flow cross-sectional area of ​​the nozzle before the hole is opened, Q0 is the central oxygen flow rate per unit area of ​​the nozzle before the hole is opened, Q2 is the increased oxygen flow rate of the nozzle after the hole is opened, S2 is the increased flow cross-sectional area of ​​the nozzle after the hole is opened, n is the number of through holes 7 set; S0 is the minimum flow cross-sectional area of ​​the through hole 7. In addition, this calculation method is established under the assumption that the increased flow area will not change the central oxygen pressure difference inside and outside the nozzle. This is because the flow rate to be increased is usually negligible relative to the total oxygen flow rate of the total water-coal slurry process burner (it has a small impact on the oxygen pressure of the process burner and will not change the gas pressure of the oxygen pipeline of the process burner).

[0051] A one-way switch is installed in the through hole 7 to only allow the fluid to flow out from the central oxygen nozzle 4 to the water-coal slurry annular gap 5.

[0052] It also includes a circulating cooling structure 8 that can use circulating cooling water to cool the water-coal slurry nozzle, and the circulating cooling structure 8 is a circulating cooling water coil arranged around the outer periphery of the outer epoxy nozzle 3. Among them, the circulating cooling water coil arranged around the outer periphery of the outer epoxy nozzle 3 can play a good cooling role, thereby improving the heat exchange efficiency of the water-coal slurry nozzle.

[0053] The working process of this embodiment:

[0054] In this embodiment, a central oxygen nozzle 1 is provided with a central oxygen spray channel 4 inside, a water-coal slurry annulus 5 is formed between the central oxygen nozzle 1 and the water-coal slurry nozzle 2, an outer epoxy annulus 6 is formed between the water-coal slurry nozzle 2 and the outer epoxy nozzle 3, and the water inlet coil and the water outlet coil of the circulating cooling water coil are respectively connected to the water inlet conduit and the water outlet conduit of the gasifier. During operation, the water-coal slurry can be sprayed along the water-coal slurry annulus 5, oxygen can be sprayed from the central oxygen spray channel 4 and the outer epoxy annulus 6, and the circulating cooling water that continuously enters and exits along the circulating cooling water coil can continuously cool the water-coal slurry nozzle.

[0055] Embodiment 2:

[0056] See also Figures 7 to 10 The axis of the through hole 7 is a spiral line (the specific style can be referred to Fig.16 ).

[0057] The number of the through holes 7 is 6 and they are evenly distributed along the circumference.

[0058] The circulating cooling structure 8 is a circulating cooling water jacket arranged in the wall of the outer epoxy nozzle 3, and the circulating cooling water flow channel of the circulating cooling water jacket has a uniform pipe diameter throughout the body. Among them, the circulating cooling water jacket arranged on the outer epoxy nozzle 3 can play a good cooling role, thereby improving the heat exchange efficiency of the water-coal slurry nozzle. In addition, the design of embodiment 1 that uses a coil wound around the outer epoxy nozzle 3 for cooling water circulation has the problems of easy slag (once sintered, it is difficult to pull out), easy burning of the front end, welds at the front end (unreliable) and a small cooling range, while this jacket design has the advantages of a smooth front end (not easy to slag), a long service life and a large cooling range.

[0059] The rest is the same as in the first embodiment.

[0060] The working process of this embodiment:

[0061] The circulating cooling water jacket is connected to the water inlet conduit and the water outlet conduit of the gasifier respectively. During operation, the circulating cooling water continuously flowing in and out of the circulating cooling water jacket can continuously cool the water-coal slurry nozzle.

[0062] The rest is the same as in the first embodiment.

[0063] Embodiment three:

[0064] See also Figures 11 to 14 The axis of the through hole 7 is an arc line (the specific style can be referred to Fig.17 ).

[0065] The number of through holes 7 is 3 and they are evenly distributed along the circumference ( Fig.17 Four through holes 7 are used as an example).

[0066] The circulating cooling structure 8 is a circulating cooling water double cone half jacket arranged in the wall of the outer epoxy nozzle 3. The circulating cooling water flow channel of the circulating cooling water double cone half jacket is provided with expansion structures at the water inlet and the water outlet respectively, and the circulating cooling water flow channel is spiral (the spiral circulating cooling water flow channel can be formed by the built-in guide plate, and the circulating cooling water flow channel in each figure is a simplified form with the spiral shape omitted). Among them, the circulating cooling water double cone half jacket arranged on the outer epoxy nozzle 3 can play a good cooling role, thereby improving the heat exchange efficiency of the water-coal slurry nozzle. In addition, the design of Example 1 that uses a coil wound around the outside of the outer epoxy nozzle 3 for cooling water circulation has the problems of easy slag (once sintered, it is difficult to pull out), easy burning of the front end, the presence of a weld at the front end (unreliable) and a small cooling range. The outer epoxy nozzle 3 of Example 2 that uses a jacket for cooling water circulation has the problems of large material consumption, great processing difficulty and high processing cost. This double-cone semi-jacketed design has the advantages of a smooth appearance (not easy to slag), simple structure and manufacturing process, and a short later maintenance and replacement cycle.

[0067] The rest is the same as in the first embodiment.

[0068] The working process of this embodiment:

[0069] The two expansion structures of the circulating cooling water double cone half jacket are respectively connected to the water inlet pipe and the water outlet pipe of the gasifier. During operation, the circulating cooling water continuously flowing in and out of the circulating cooling water double cone half jacket can continuously cool the water-coal slurry nozzle.

[0070] The rest is the same as in the first embodiment.

[0071] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A water-coal slurry nozzle capable of simultaneously increasing the coal slurry pressure difference and the central oxygen flow rate, characterized in that: The invention comprises a central oxygen nozzle (1), a water-coal slurry nozzle (2) and an outer epoxy nozzle (3) which are nested layer by layer from the axis side to the axis outside. A through hole (7) is provided on the central oxygen nozzle (1). The through hole (7) can connect a central oxygen spray channel (4) located inside the central oxygen nozzle (1) and a water-coal slurry annular gap (5) located between the central oxygen nozzle (1) and the water-coal slurry nozzle (2).

2. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: The outlet ends of the central oxygen nozzle (1), the water-coal slurry nozzle (2) and the outer epoxy nozzle (3) are respectively provided with a central oxygen nozzle body cone section, a water-coal slurry nozzle body cone section and an outer epoxy nozzle body cone section which gradually narrow outwards, and the through hole (7) is provided at the central oxygen nozzle body cone section.

3. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: The cross-sectional area of ​​the through hole (7) located on the inner surface of the tube wall of the central oxygen nozzle (1) is smaller than the cross-sectional area of ​​the through hole located on the outer surface of the tube wall of the central oxygen nozzle (1).

4. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: The axis center line of the through hole (7) is a straight line, an arc line or a spiral line.

5. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: The cross section of the through hole (7) is circular and the surface of the hole wall is smooth.

6. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: The number of the through holes (7) is no less than 2 and is evenly distributed along the circumference.

7. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 6, characterized in that: The number of the through holes (7) is calculated according to formula (a), formula (b) and formula (c); In the formula, Q1 is the central oxygen flow rate of the nozzle before the hole is opened, S1 is the central oxygen flow cross-sectional area of ​​the nozzle before the hole is opened, Q0 is the oxygen flow rate per unit area of ​​the nozzle before the hole is opened, Q2 is the increased oxygen flow rate of the nozzle after the hole is opened, S2 is the increased flow cross-sectional area of ​​the nozzle after the hole is opened, n is the number of through holes (7) set, and S0 is the minimum flow cross-sectional area of ​​the through hole (7).

8. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 1, characterized in that: A one-way switch is installed in the through hole (7) to only allow fluid to flow out from the central oxygen spray channel (4) to the water-coal slurry annular gap (5).

9. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to any one of claims 1 to 8, characterized in that: It also includes a circulating cooling structure (8) that can utilize circulating cooling water to cool the water-coal slurry nozzle.

10. The water-coal slurry nozzle capable of synchronously improving the coal slurry pressure difference and the central oxygen flow rate according to claim 9, characterized in that: The circulating cooling structure (8) is a circulating cooling water coil arranged around the outer periphery of the outer epoxy nozzle (13), a circulating cooling water jacket arranged in the wall of the outer epoxy nozzle (13), or a circulating cooling water double-cone half jacket arranged in the wall of the outer epoxy nozzle (13). The circulating cooling water flow channel of the circulating cooling water jacket has a uniform pipe diameter throughout the body. The circulating cooling water flow channel of the circulating cooling water double-cone half jacket is provided with expansion structures at the water inlet and the water outlet respectively, and the circulating cooling water flow channel is spiral-shaped.

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