A coal gasification high-temperature pyrolysis gas cooling and washing device

Abstract

This invention discloses a high-temperature pyrolysis gas cooling and washing device for coal gasification. It is characterized by comprising a pyrolysis gas channel (4) connected to the gas outlet of the gasification chamber for the flow of high-temperature pyrolysis gas, a spray water annular gap (3) disposed around the outer periphery of the pyrolysis gas channel (4), and an external cooling water annular gap (2) disposed around the outer periphery of the spray water annular gap (3). Spray holes (5) are provided on the inner wall of the spray water annular gap (3). The spray water in the spray water annular gap (3) is used to spray and cool the pyrolysis gas channel (4), and the external cooling water in the external cooling water annular gap (2) is used to cool both the spray water annular gap (3) and the pyrolysis gas channel (4). This high-temperature pyrolysis gas cooling and washing device for coal gasification has a simple structure and can simultaneously solve the problems of cooling the high-temperature pyrolysis gas conveying pipeline and washing the pyrolysis gas.

Description

Technical Field

[0001] This invention relates to the field of coal gasification technology, and in particular to a high-temperature pyrolysis gas cooling and washing device for coal gasification. Background Technology

[0002] High-temperature syngas cooling methods include quenching processes and waste heat boiler processes. Examples of quenching processes include Texaco gasification technology, multi-nozzle gasification technology, aerospace gasification technology, and the second-generation Tsinghua Furnace gasification technology. Examples of waste heat boiler processes include Shell gasification technology and the third-generation Tsinghua Furnace. Related explanations are as follows:

[0003] Texaco gasification technology corresponds to the Texaco gasification unit, whose quench chamber is equipped with a quench ring, downcomer, and riser. Washing and cooling water enters the quench chamber through two paths: one path sprays at a 45° angle into the quench ring and forms a water film along the downcomer; the other path is directly fed into the water bath. The quench ring nozzles cool the syngas, and the water film in the downcomer protects it from deformation caused by the high-temperature syngas heat radiation. The syngas enters the quench chamber through the gasifier slag inlet, is quenched by water spray from the quench ring, and then enters the quench chamber water bath along the downcomer. After being washed in the quench chamber water bath, it rises along the annular gap of the downcomer and riser before exiting the gasifier quench chamber.

[0004] The four-nozzle gasification technology within the multi-nozzle gasification technology features a quench chamber incorporating a quench ring, downcomer, and bubble-breaking strips, forming a composite washing and cooling structure that combines a spray bed and a bubbling bed. Compared to Texaco's gasification technology, it eliminates the riser and adds bubble-breaking strips and other structures.

[0005] Shell gasification technology uses high-temperature crude syngas at approximately 3.96 MPa and 1500°C at the top of the gasifier. This syngas is then cooled to below 900°C by quench gas at 209°C before entering a waste heat boiler to produce steam. After recovering heat, the steam then enters a ceramic filter dry ash removal and wet scrubbing system.

[0006] In the prior art, the dust-laden gas mixer scrubbing device includes a syngas pipe and an ash water pipe. The spray nozzle of the ash water pipe is connected to the syngas pipe. A sleeve is installed inside the syngas pipe, and the spray nozzle of the ash water pipe is opposite to the air inlet of the sleeve. A hydrocyclone is installed near the spray nozzle of the ash water pipe. By installing a hydrocyclone near the spray nozzle of the ash water pipe, the hydrocyclone can achieve initial atomization of the scrubbing water. However, the cooling scrubbing device has a long process flow and complex structure; the upward discharge of pyrolysis gas from the gasifier faces difficulties in selecting materials for the high-temperature pyrolysis gas transmission pipeline.

[0007] Because the high-temperature pyrolysis gas is discharged from the top of the pyrolysis chamber, and due to the burner setup in the pyrolysis chamber, the swirling flow field inside the pyrolysis chamber enables the directional transport of the pyrolysis semi-coke. The dust content of the top pyrolysis gas is relatively small, so there is no need for traditional multi-stage washing (quench chamber + Venturi + washing tower) and no need for the long syngas washing process of traditional coal gasification technology.

[0008] In summary, how to provide a high-temperature pyrolysis gas cooling and washing device for coal gasification that can effectively solve the problems of cooling and washing high-temperature pyrolysis gas at 800-900℃ is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] The purpose of this invention is to provide a coal gasification high-temperature pyrolysis gas cooling and washing device. This coal gasification high-temperature pyrolysis gas cooling and washing device has a simple structure and can simultaneously solve the problems of cooling the high-temperature pyrolysis gas conveying pipeline and washing the pyrolysis gas.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0011] A coal gasification high-temperature pyrolysis gas cooling and washing device includes a pyrolysis gas channel connected to the gas outlet of the gasification chamber for the flow of high-temperature pyrolysis gas, a spray water annular gap disposed around the outer periphery of the pyrolysis gas channel, and an external cooling water annular gap disposed around the outer periphery of the spray water annular gap. The inner wall of the spray water annular gap is provided with spray holes. The spray water in the spray water annular gap is used to spray and cool the pyrolysis gas channel. The external cooling water in the external cooling water annular gap is used to cool the spray water annular gap and the pyrolysis gas channel.

[0012] Preferably, the pyrolysis gas channel includes a constricted section at the high-temperature pyrolysis gas inlet, a throat section in the middle section, and a flared section at the outlet.

[0013] Preferably, the angle of the constricted section is greater than the angle of the flared section.

[0014] Preferably, the water spray holes are disposed on the throat section, and the number of water spray holes is multiple.

[0015] Preferably, the water spray holes are evenly distributed.

[0016] Preferably, the ratio of the flow rate of the high-temperature pyrolysis gas to the flow rate of the spray water is less than 125.

[0017] Preferably, the flow velocity of the high-temperature pyrolysis gas in the throat section is 40-60 m / s, and the diameter of the water spray hole is 2-5 mm.

[0018] Preferably, the length of the larynx segment is greater than or equal to twice the diameter of the larynx.

[0019] Preferably, the outer casing of the external cooling water annulus is provided with a cooling water inlet on the upper side and a cooling water outlet on the lower side, the cooling water inlet being connected to the cooling water inlet pipe and the cooling water outlet being connected to the cooling water outlet pipe.

[0020] The upper side of the outer wall of the spray water annulus is provided with a spray water inlet, and the lower side is provided with a spray water outlet. The spray water inlet is connected to the spray water inlet pipe, and the spray water outlet is connected to the spray water outlet pipe.

[0021] Preferably, the outer wall of the spray water annular gap is the inner wall of the external cooling water annular gap, and the spray water inlet pipe and spray water outlet pipe pass through the outer shell of the external cooling water annular gap in a sealed manner.

[0022] The high-temperature pyrolysis gas cooling and washing device for coal gasification provided by this invention includes a pyrolysis gas channel, a spray water annulus, and an external cooling water annulus. The pyrolysis gas channel is located in the middle and is connected to the gas outlet of the gasification chamber. The high-temperature pyrolysis gas from the gasification chamber enters from the inlet of the pyrolysis gas channel, flows through the pyrolysis gas channel, and exits from the outlet of the pyrolysis gas channel. The material of the pyrolysis gas channel can be a nickel-based alloy, such as Incoloy 825, which has resistance to acid and alkali metal corrosion in both oxidizing and reducing environments.

[0023] A spray water annular gap is located on the outer periphery of the pyrolysis gas channel, and spray water flows through the annular gap. Spray holes are provided on the inner wall of the spray water annular gap. Spray water is sprayed into the pyrolysis gas channel through the spray holes, directed at the high-temperature pyrolysis gas. The spray water evaporates and atomizes, carrying away the heat within the pyrolysis gas channel, thus providing spray cooling to the pyrolysis gas channel. Simultaneously, the spray water washes the annular gap as it flows through it.

[0024] An external cooling water annulus is located on the outer periphery of the spray water annulus, and external cooling water flows through the external cooling water annulus. The inner wall of the external cooling water annulus is in contact with the outer wall of the spray water annulus. The external cooling water has a lower temperature and exchanges heat with the spray water annulus, which has a higher temperature. In this way, the external cooling water cools the spray water annulus and the pyrolysis gas passage.

[0025] The coal gasification high-temperature pyrolysis gas cooling and washing device provided by this invention can simultaneously complete the cooling of the pyrolysis gas channel and the washing of the high-temperature pyrolysis gas at 800-900℃ with low dust content. Moreover, the process is shorter and does not require the long syngas washing process of traditional coal gasification technology. It can reduce the difficulty of material selection for the pyrolysis gas channel, and has a simple structure and low cost. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1This is a schematic diagram of the structure of a coal gasification high-temperature pyrolysis gas cooling and washing device provided in a specific embodiment of the present invention.

[0028] The following labels are shown in the attached diagram:

[0029] 1. Outer shell, 2. External cooling water annular gap, 3. Spray water annular gap, 4. Pyrolysis gas channel, 5. Spray hole, 6. Cooling water inlet pipe, 7. Cooling water outlet pipe, 8. Spray water inlet pipe, 9. Narrowing section, 41. Throat section, 42. Widening section, 43. Detailed Implementation

[0030] The core of this invention is to provide a coal gasification high-temperature pyrolysis gas cooling and washing device. This coal gasification high-temperature pyrolysis gas cooling and washing device has a simple structure and can simultaneously solve the problems of cooling the high-temperature pyrolysis gas conveying pipeline and washing the pyrolysis gas.

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a coal gasification high-temperature pyrolysis gas cooling and washing device provided in a specific embodiment of the present invention.

[0033] In one specific embodiment, the coal gasification high-temperature pyrolysis gas cooling and washing device provided by the present invention includes a pyrolysis gas channel 4 connected to the gas outlet of the gasification chamber for flowing through the high-temperature pyrolysis gas, a spray water annular gap 3 disposed on the outer periphery of the pyrolysis gas channel 4, and an external cooling water annular gap 2 disposed on the outer periphery of the spray water annular gap 3. Spray holes 5 are provided on the inner wall of the spray water annular gap 3. The spray water in the spray water annular gap 3 is used to spray and cool the pyrolysis gas channel 4, and the external cooling water in the external cooling water annular gap 2 is used to cool the spray water annular gap 3 and the pyrolysis gas channel 4.

[0034] In the above structure, the coal gasification high-temperature pyrolysis gas cooling and scrubbing device includes a pyrolysis gas channel 4, a spray water annular gap 3, and an external cooling water annular gap 2. The pyrolysis gas channel 4 is located in the middle and is connected to the gas outlet of the gasification chamber. The high-temperature pyrolysis gas from the gasification chamber enters from the inlet of the pyrolysis gas channel 4, flows through the pyrolysis gas channel 4, and exits from the outlet of the pyrolysis gas channel 4. The material of the pyrolysis gas channel 4 can be a nickel-based alloy, such as Incoloy 825, which has resistance to acid and alkali metal corrosion in both oxidizing and reducing environments.

[0035] A spray water annular gap 3 is located on the outer periphery of the pyrolysis gas channel 4, and spray water flows through the spray water annular gap 3. Spray holes 5 are provided on the inner wall of the spray water annular gap 3. Spray water is sprayed into the pyrolysis gas channel 4 through the spray holes 5, and sprayed towards the high-temperature pyrolysis gas. The spray water evaporates and atomizes, carrying away the heat within the pyrolysis gas channel 4, thus spraying and cooling the pyrolysis gas channel 4. Simultaneously, the spray water flows through the spray water annular gap 3, washing the spray water annular gap 3.

[0036] An external cooling water annular gap 2 is located on the outer periphery of the spray water annular gap 3, and external cooling water flows through the external cooling water annular gap 2. The inner wall of the external cooling water annular gap 2 is in contact with the outer wall of the spray water annular gap 3. The external cooling water has a lower temperature and exchanges heat with the spray water annular gap 3, which has a higher temperature. In this way, the external cooling water cools the spray water annular gap 3 and the pyrolysis gas channel 4.

[0037] The coal gasification high-temperature pyrolysis gas cooling and washing device provided by the present invention can simultaneously complete the cooling of the pyrolysis gas channel 4 and the high-temperature pyrolysis gas washing work for 800-900℃ high-temperature pyrolysis gas with low dust content; and the process is shorter, without the need for the long syngas washing process of traditional coal gasification technology, which can reduce the difficulty of material selection for the pyrolysis gas channel 4, and has a simple structure and low cost.

[0038] Based on the above specific implementation method, the pyrolysis gas channel 4 includes a constriction section 41, a throat section 42, and a flaring section 43. The constriction section 41 is located at the high-temperature pyrolysis gas inlet, the throat section 42 is located in the middle section, and the flaring section 43 is located at the outlet.

[0039] The pyrolysis gas channel 4 is designed with a constriction-expansion structure. The constriction section 41 increases the velocity of the high-temperature pyrolysis gas, and the velocity difference between the high-temperature pyrolysis gas and the sprayed water enhances the spraying and atomization effects. The expansion section 43 slows down the outflowing high-temperature pyrolysis gas, ensuring the stability of the high-temperature pyrolysis gas flow.

[0040] Preferably, the angle of the constricted section 41 is greater than the angle of the flared section 43. For example, the angle α of the constricted section 41 can be any value between 12-14°, including the endpoint value, such as 13mm. A larger angle in the constricted section 41 can reduce the overall length of the device. The angle β of the flared section 43 can be any value between 2-4°, including the endpoint value, such as 3mm. A smaller angle in the flared section 43 results in more stable flow of high-temperature pyrolysis gas after spray cooling.

[0041] Based on the above specific embodiments, the water spray holes 5 are disposed on the throat section 42. The water spray holes 5 are easy to set, have good stability, and are not easily vibrated. The throat section 42 of the spray water annular gap 3 is relatively long. Multiple water spray holes 5 are opened on the throat section 42. By increasing the number of water spray holes 5, the spray water is dispersed, ensuring that the high-temperature pyrolysis gas at the throat section 42 can be sprayed and cooled at different positions, which is beneficial to improving washing efficiency and cooling effect.

[0042] Based on the above specific embodiments, the spray holes 5 can be evenly distributed on the throat section 42, resulting in more thorough and uniform dispersion of the sprayed water, and more uniform overall washing and cooling of the high-temperature pyrolysis gas. Of course, the even distribution of the spray holes 5 on the throat section 42 is only a preferred embodiment, not the only one. They can also be unevenly distributed; for example, there can be more spray holes 5 in the middle, with a denser distribution, while fewer spray holes 5 are present at both ends, with a more dispersed distribution. The specific distribution of the spray holes 5 is not limited and can be determined according to the actual application.

[0043] Based on the above specific embodiments, the flow rate ratio of high-temperature pyrolysis gas to spray water is less than 125, that is, the volume ratio of high-temperature pyrolysis gas flow rate to spray water is less than 125. For example, the volume of the external cooling water annulus 2 is 316L, the volume of the spray water annulus 3 is 316L, the flow velocity of high-temperature pyrolysis gas in the throat section 42 is any value between 40-60m / s, including the endpoint value, for example, 50m / s, and the diameter of the spray hole 5 is any value between 2-5mm, including the endpoint value, for example, 4mm. This ensures that the high-temperature pyrolysis gas flowing through can be sprayed and atomized with sufficient spray water to meet the cooling and washing requirements of the high-temperature pyrolysis gas.

[0044] Based on the above specific embodiments, the length of the throat section 42 is greater than or equal to twice the diameter of the throat. The larger throat length allows for the installation of a larger number of water spray holes 5, which not only increases the cooling area but also increases the opening area of ​​the water spray holes 5, preventing excessive local spraying of cooling water from causing pipe vibration.

[0045] In another more reliable embodiment, based on any of the above embodiments, a cooling water inlet is provided on the upper side of the outer shell 1 of the external cooling water annular gap 2, and a cooling water outlet is provided on the lower side. The cooling water inlet is connected to the cooling water inlet pipe 6, and the cooling water outlet is connected to the cooling water outlet pipe 7. A spray water inlet is provided on the upper side of the outer wall of the spray water annular gap 3, and a spray water outlet is provided on the lower side. The spray water inlet is connected to the spray water inlet pipe 8, and the spray water outlet is connected to the spray water outlet pipe 9. The structures of the spray water annular gap 3 and the external cooling water annular gap 2 are simple, allowing spray water and external cooling water to be introduced in real time, ensuring that the water temperature of the spray water and external cooling water is low, and having a good cooling effect.

[0046] Based on the above specific embodiments, the outer wall of the spray water annular gap 3 is the inner wall of the external cooling water annular gap 2. The spray water inlet pipe 8 and the spray water outlet pipe 9 pass through the outer shell 1 of the external cooling water annular gap 2 in a sealed manner. The spray water annular gap 3 and the external cooling water annular gap 2 are separated by only one wall surface. The outer wall of the spray water annular gap 3 is wrapped in the external cooling water, resulting in better cooling and heat exchange effect.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0048] The high-temperature pyrolysis gas cooling and washing device for coal gasification provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention. Therefore, this invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coal gasification high-temperature pyrolysis gas cooling and washing device, characterized in that, For high-temperature pyrolysis gas with low dust content at 800-900℃, the cooling of the pyrolysis gas channel (4) and the washing of the high-temperature pyrolysis gas are completed simultaneously. This includes a pyrolysis gas channel (4) connected to the gas outlet of the gasification chamber for the flow of high-temperature pyrolysis gas, a spray water annular gap (3) set on the outer periphery of the pyrolysis gas channel (4), and an external cooling water annular gap (2) set on the outer periphery of the spray water annular gap (3). The inner wall of the spray water annular gap (3) is provided with spray holes (5). The spray water in the spray water annular gap (3) is used to spray and cool the pyrolysis gas channel (4). The external cooling water in the external cooling water annular gap (2) is used to cool the spray water annular gap (3) and the pyrolysis gas channel (4). The outer shell (1) of the external cooling water annular gap (2) is provided with a cooling water inlet on the upper side and a cooling water outlet on the lower side. The cooling water inlet is connected to the cooling water inlet pipe (6) and the cooling water outlet is connected to the cooling water outlet pipe (7). The upper side of the outer wall of the spray water annular gap (3) is provided with a spray water inlet, and the lower side is provided with a spray water outlet. The spray water inlet is connected to the spray water inlet pipe (8), and the spray water outlet is connected to the spray water outlet pipe (9). The outer wall of the spray water annular gap (3) is the inner wall of the external cooling water annular gap (2). The spray water inlet pipe (8) and the spray water outlet pipe (9) pass through the outer shell (1) of the external cooling water annular gap (2) in a sealed manner. The pyrolysis gas channel (4) includes a constricted section (41) at the inlet of high-temperature pyrolysis gas, a throat section (42) in the middle section, and an flared section (43) at the outlet. The angle of the constricted section (41) is greater than the angle of the flared section (43). The water spray hole (5) is set on the throat section (42). There are multiple water spray holes (5). The ratio of the flow rate of the high-temperature pyrolysis gas to the flow rate of the spray water is less than 125. The length of the throat section (42) is greater than or equal to twice the diameter of the throat.

2. The coal gasification high-temperature pyrolysis gas cooling and washing device according to claim 1, characterized in that, The water spray holes (5) are evenly distributed.

3. The coal gasification high-temperature pyrolysis gas cooling and washing device according to claim 1, characterized in that, The flow velocity of the high-temperature pyrolysis gas in the throat section (42) is 40-60 m / s, and the diameter of the water spray hole (5) is 2-5 mm.

Images