Multi-nozzle coal water slurry supercritical water gasification reactor
By employing a multi-nozzle and spiral guide vane design in the supercritical water gasification reactor, the problems of uneven coal powder distribution and insufficient heat and mass transfer were solved, achieving efficient coal conversion and high carbon gasification rate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2022-12-23
- Publication Date
- 2026-08-04
AI Technical Summary
In existing supercritical water gasification reactors for coal, uneven distribution of pulverized coal and insufficient heat and mass transfer lead to a decrease in reaction rate and carbon gasification rate.
A multi-nozzle supercritical water gasification reactor for coal-water slurry is adopted. By setting multiple rows of circumferentially spaced coal-water slurry nozzles and spiral guide vanes in the reactor, the mixing of pulverized coal and supercritical water and the heat and mass transfer are enhanced by high-speed tangential injection of supercritical water and swirling effect.
This method achieves uniform distribution and rapid heating of pulverized coal in the gasification zone, enhances the heat and mass transfer process, improves the reaction rate and carbon gasification rate, and increases the overall conversion efficiency of the reactor.
Smart Images
Figure CN115926847B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of coal high-efficiency conversion technology, specifically relating to a multi-nozzle supercritical water gasification reactor for coal-water slurry. Background Technology
[0002] Currently, coal accounts for 57% of total primary energy production. Forecasts indicate that coal's dominant role in the energy production and consumption structure will remain unchanged for the next few decades. However, the traditional method of coal utilization is primarily direct combustion, which is not only inefficient but also produces air pollutants such as SOx and NOx, as well as large amounts of dust. Therefore, developing advanced, clean, and efficient coal conversion technologies is of great significance to the development of my country's energy sector.
[0003] Supercritical water gasification technology for coal is a new type of coal gasification technology that has been developed in recent years. Supercritical water gasification technology can gasify coal in a reducing atmosphere at a relatively low temperature, while N, S, ash and other substances in the coal are mainly discharged from the gasifier in the form of sludge. The gas products contain no NOx, SOx and soot, which greatly reduces pollution and damage to the environment. It also has the advantages of fast reaction rate and high hydrogen content in gas products.
[0004] Due to the high-pressure environment (≥22.1MPa) in the supercritical water gasification system of coal, it is difficult to transport pulverized coal into the reactor by high-speed gas flow. Therefore, in the supercritical water gasification system of coal, pulverized coal is usually transported into the reactor in the form of coal-water slurry.
[0005] Existing supercritical water gasification technologies for coal often employ a single-nozzle structure and generally lack internal components designed for different coal types. This may result in uneven distribution of pulverized coal within the supercritical water reactor. Furthermore, under conditions of uneven flow field distribution within the reactor, pulverized coal may even agglomerate into lumps. These factors will lead to a deterioration in heat and mass transfer between supercritical water and pulverized coal, and a reduction in gasification efficiency. Summary of the Invention
[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a multi-nozzle supercritical water gasification reactor for coal-water slurry. This reactor solves the technical problem of reduced reaction rate and carbon gasification rate caused by uneven coal powder distribution and insufficient heat and mass transfer in existing supercritical water reactors for coal, thereby improving the overall conversion rate and throughput of the supercritical water gasification reactor for coal.
[0007] The present invention adopts the following technical solution:
[0008] A multi-nozzle supercritical water gasification reactor for coal-water slurry includes a shell, a hydrogen-oxygen exothermic zone is provided at the center of the upper part of the shell, and a gasification zone is provided in the annular area between the hydrogen-oxygen exothermic zone and the shell.
[0009] An oxidant inlet pipe is vertically installed inside the hydrogen-oxygen exothermic zone. One end of the oxidant inlet pipe extends to the outside of the shell, and a product outlet is provided between the oxidant inlet pipe and the shell.
[0010] The outer shell of the gasification zone is equipped with a supercritical water inlet and a coal-water slurry nozzle. The supercritical water inlet is arranged along the tangential direction of the shell, and the coal-water slurry nozzle is arranged in multiple rows from top to bottom along the shell.
[0011] A slag discharge area is provided at the lower interior of the shell, and a slag discharge port is provided at the bottom of the shell.
[0012] Specifically, each coal slurry nozzle includes four nozzles, which are spaced apart circumferentially along the shell.
[0013] Furthermore, the angle between the nozzle and the horizontal direction is 1 to 45°.
[0014] Specifically, the supercritical water inlet is positioned directly opposite the outlet of the uppermost coal slurry nozzle and is perpendicular to the corresponding coal slurry nozzle.
[0015] Specifically, a first spiral guide vane is provided on the outer side of the sleeve, and a second spiral guide vane is provided on the inner side of the shell.
[0016] Furthermore, the first and second helical guide vanes are made of one or more helical linear blades.
[0017] Furthermore, the first and second helical guide vanes are each provided with 4 to 6 layers on the sleeve and the shell.
[0018] Furthermore, the angle between the first and second helical guide vanes and the horizontal plane is 45° to 60°.
[0019] Specifically, corresponding thermocouples are installed in the shell, the hydrogen-oxygen exothermic zone, and the vaporization zone.
[0020] Specifically, the casing, product outlet, and oxidant inlet pipe are coaxially arranged.
[0021] Compared with the prior art, the present invention has at least the following beneficial effects:
[0022] A multi-nozzle supercritical water gasification reactor for coal-water slurry includes an exothermic hydrogen-oxygen reaction zone enclosed by a casing, and a gasification zone in an annular region between the casing and the outer shell. Within the exothermic zone, the oxidant reacts with hydrogen from the gaseous products in a partially exothermic hydrogen-oxygen reaction, providing heat for the gasification zone. Within the gasification zone, pulverized coal reacts with supercritical water to generate hydrogen-rich gaseous products. A conical ash discharge zone is located at the bottom of the reactor to collect the ash generated after coal gasification, facilitating subsequent discharge.
[0023] Furthermore, the coal-water slurry nozzles are arranged in multiple rows from top to bottom along the shell, with each coal-water slurry nozzle including four nozzles. The four nozzles are arranged at intervals along the circumference of the shell, so that the coal-water slurry is uniformly distributed throughout the reactor space, which is beneficial to the rapid heating and diffusion of coal powder.
[0024] Furthermore, the nozzle is angled between 1 and 45° and the horizontal direction, causing the coal-water slurry to enter the reactor in an upward parabolic shape, resulting in more intense collisions with the downward-flowing supercritical water and enhancing heat and mass transfer.
[0025] Furthermore, the supercritical water inlet is positioned directly opposite the outlet of the uppermost coal slurry nozzle and perpendicular to the corresponding coal slurry nozzle, tangent to the reactor shell. This facilitates the formation of a swirling motion of the supercritical water within the gasification zone, while simultaneously ensuring that it collides with the coal slurry at the inlet of all nozzles and drives the movement of pulverized coal.
[0026] Furthermore, a first spiral guide vane is provided on the outer side of the casing, and a second spiral guide vane is provided on the inner side of the shell. The first spiral guide vane and the second spiral guide vane effectively enhance the swirling effect in the reactor. At the same time, the first spiral guide vane acts as a rib, enhancing the heat transfer efficiency between the hydrogen-oxygen exothermic zone and the gasification zone.
[0027] Furthermore, depending on the reactor size, the first and second helical guide vanes can be made of one or more helical linear blades, thereby reducing the difficulty of processing.
[0028] Furthermore, the first and second helical guide vanes are arranged in 4 to 6 layers, which can reduce the processing difficulty and material usage while ensuring the enhanced swirling effect.
[0029] Furthermore, the angle between the first and second helical guide vanes and the horizontal plane is 45-60°, which promotes the swirling effect while preventing coal dust from depositing on the guide vanes.
[0030] Furthermore, corresponding thermocouples are installed in the shell, the hydrogen-oxygen exothermic zone, and the vaporization zone to facilitate the control of the reactor's operating temperature by the operators.
[0031] In summary, this invention employs multiple rows of circumferentially spaced coal-water slurry nozzles to achieve uniform feeding of the coal-water slurry. Simultaneously, it utilizes high-speed tangentially injected supercritical water and added spiral guide blades to create a swirling effect in the gasification zone. The swirling supercritical water collides with the coal-water slurry, enhancing the heat and mass transfer and mixing process between pulverized coal and supercritical water in the gasification zone, thereby improving the reaction rate and carbon gasification rate.
[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the reactor structure of the present invention;
[0034] Figure 2 This is a schematic diagram of the side nozzle and supercritical water inlet of the present invention.
[0035] Wherein: 1. Shell; 2. Casing; 3. Supercritical water inlet; 4. Nozzle; 41. First nozzle; 42. Second nozzle; 43. Third nozzle; 44. Fourth nozzle; 5. Product outlet; 6. Oxidant inlet pipe; 7. First spiral guide vane; 8. Second spiral guide vane; 9. Slag discharge port; 10. Hydrogen-oxygen exothermic zone; 11. Gasification zone; 12. Slag discharge zone. Detailed Implementation
[0036] 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, not all, of the embodiments of the present invention. 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.
[0037] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0038] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0039] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.
[0040] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0041] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0042] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.
[0043] This invention provides a multi-nozzle supercritical water gasification reactor for coal-water slurry. It utilizes high-speed tangentially injected supercritical water and added spiral guide blades to create a swirling effect in the gasification zone. The downward-flowing supercritical water collides with the upward-injected coal-water slurry and forms a rotational motion within the gasification zone, which enhances the heat and mass transfer and mixing process, accelerates the reaction rate, and is beneficial to improving the carbon conversion rate. In addition, the slag discharge zone adopts a conical space, which is conducive to the enrichment and discharge of residues.
[0044] Please see Figure 1 The present invention provides a multi-nozzle supercritical water gasification reactor for coal-water slurry, comprising a shell 1, a hydrogen-oxygen exothermic zone 10, a gasification zone 11, a slag discharge zone 12, and nozzles 4.
[0045] The shell 1 is equipped with a sleeve 2. The cavity enclosed by the sleeve 2 constitutes the hydrogen-oxygen exothermic zone 10. The annular area between the sleeve 2 and the shell 1 constitutes the vaporization zone 11. The conical area at the bottom of the shell 1 is the slag discharge zone 12. The shell 1, the hydrogen-oxygen exothermic zone 10 and the vaporization zone 11 are all equipped with corresponding thermocouples to monitor the temperature of the vaporization zone 11 and the hydrogen-oxygen exothermic zone 10, ensuring that they are within the set temperature range, thereby guaranteeing the normal operation of the system.
[0046] The upper part of the sleeve 2 is connected to the shell 1 and is on the same axis as the shell 1. The bottom is open. The hydrogen-rich gas product after coal gasification and the supercritical water flow back upward and enter the hydrogen-oxygen exothermic zone 11 from the bottom of the sleeve 2. The top of the hydrogen-oxygen exothermic zone 10 is provided with an oxidant inlet pipe 6 and a product outlet 5. The oxidant inlet pipe 6 is coaxial with the sleeve 2 and located on the same axis. The product outlet 5 is an outer annular area coaxial with the oxidant inlet pipe 6. The product after the hydrogen-oxygen reaction flows out from the annular product outlet 5, which achieves the effect of preheating the oxidant entering the reactor. The high-temperature supercritical fluid flowing out of the reactor is used for energy recovery and utilization through a heat exchanger. The recovered energy is used to raise the temperature of the supercritical water entering the reactor.
[0047] Please see Figure 2 A supercritical water inlet 3 and a nozzle 4 are provided on the upper side wall of the shell 1 in the gasification zone 11. The supercritical water inlet 3 is arranged along the tangential direction of the shell 1. The nozzle 4 includes multiple nozzles, which are arranged in multiple rows along the longitudinal direction of the shell 1, with four nozzles in each row and evenly distributed in the circumferential direction. The nozzle structure makes the coal slurry entering the reactor more evenly distributed in the space of the gasification zone 11, which is conducive to enhancing the diffusion of coal powder in the gasification zone 11.
[0048] The nozzle 4 is inclined downward along the housing 1, with an angle of 1 to 45° with the horizontal direction, preferably 30°. The four nozzles in the upper row are the first nozzle 41, the second nozzle 42, the third nozzle 43 and the fourth nozzle 44.
[0049] The supercritical water inlet 3 is at the same height as the four nozzles 4 in the upper row, and the outlet of the first nozzle 41 is directly opposite to the supercritical water inlet 3.
[0050] For non-coking coal types, a first spiral guide vane 7 and a second spiral guide vane 8 are respectively added to the outer wall of the casing 2 and the inner wall of the shell 1 to enhance the control of the flow field. The first spiral guide vane 7 and the second spiral guide vane 8 are both one or more spiral linear vanes, each with 4 to 6 layers, and the angle with the horizontal plane is 45 to 60°, preferably 55°.
[0051] Supercritical water, injected tangentially at high speed from supercritical water inlet 3, forms a swirling effect in gasification zone 11 under the combined action of the first helical guide vane 7 and the second helical guide vane 8. The downward-swirling supercritical water collides with the upward-splitting coal slurry in gasification zone 11, thereby driving the coal powder to swirl in gasification zone 11, making the heat and mass transfer and mixing process more rapid, accelerating the reaction rate and improving the carbon conversion rate.
[0052] The conical space at the bottom of the shell 1 is the slag discharge zone 12 of the reactor. A slag discharge port 9 is provided at the bottom center of the shell 1. The residue after supercritical water gasification of coal accumulates in the slag discharge zone 12 and is periodically discharged from the slag discharge port 9 through a step-by-step depressurization method.
[0053] The working process of a multi-nozzle supercritical water gasification reactor for efficient coal conversion is as follows:
[0054] After being crushed, ground, and screened, coal powder with a mesh size of less than 200 is obtained. After adding catalyst and stabilizer, it is made into a coal-water slurry with a concentration of 30% to 60%, which is then injected obliquely upward into the gasification zone 11 through nozzle 4.
[0055] Supercritical water heated to a high temperature of 650-720℃ is injected tangentially at high speed into the gasification zone 11 through the supercritical water inlet 3. Under the combined action of the first spiral guide vane 7 and the second spiral guide vane 8, a swirling effect is formed in the gasification zone 11. The supercritical water moving downwards in the swirling flow collides with the coal slurry injected upwards at an angle in the gasification zone 11, causing the coal powder to heat up rapidly in the gasification zone 11 and undergo a rapid gasification reaction with the supercritical water to generate gaseous products with CO2 and H2 as the main components. The ash in the coal that cannot be gasified forms residue.
[0056] Gas products, residues and supercritical water swirl downwards and flow out from the bottom of the gasification zone 11. Solid residues are enriched in the slag discharge zone 12 and then periodically discharged through the slag discharge port 9 by a step-by-step pressure reduction method.
[0057] The gaseous products and supercritical water flow back upwards from the bottom of the casing 2 into the hydrogen-oxygen exothermic zone 10. The oxidant is sent to the lower part of the hydrogen-oxygen exothermic zone 10 through the oxidant inlet pipe 6, and moves back upwards together with the supercritical water and gaseous products entering from the bottom of the casing 2. During this process, the oxidant and hydrogen in the gaseous products undergo a partial hydrogen-oxygen exothermic reaction to release heat. The heat released by the hydrogen-oxygen exothermic zone 11 provides the required heat for the supercritical water gasification of coal in the gasification zone 10. The first spiral guide vane 7 added to the outer wall of the casing 2 also acts as a rib, enhancing the heat transfer efficiency between the hydrogen-oxygen exothermic zone 11 and the gasification zone 10.
[0058] By adjusting the flow rate of the oxidant, the temperature of the gasification zone is controlled at 650-720℃. Part of the supercritical fluid after the hydrogen-oxygen reaction flows out from the annular product outlet 5. The high-temperature supercritical fluid that flows out can recover heat through a heat exchanger. The hydrogen-rich gaseous product can be collected as chemical raw materials or fuel for further processing. The entire reaction process achieves efficient coal conversion.
[0059] In summary, the multi-nozzle supercritical water gasification reactor of the present invention can utilize the swirling effect of supercritical water to collide with multiple streams of coal-water slurry, thereby driving the coal powder to rotate within the gasification zone. This directly enhances the mixing and heat and mass transfer process between supercritical water and coal powder, effectively improving the carbon gasification rate and the overall efficiency of the reactor, thus achieving efficient utilization of coal.
[0060] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.
Claims
1. A multi-nozzle coal water slurry supercritical water gasification reactor, characterized by, Includes a shell (1), a hydrogen-oxygen exothermic zone (10) is provided at the center of the upper part of the shell (1), and a vaporization zone (11) is provided in the annular area between the hydrogen-oxygen exothermic zone (10) and the shell (1). The shell (1) is provided with a sleeve (2), the cavity enclosed by the sleeve (2) constitutes the hydrogen-oxygen exothermic zone (10), and the annular area between the sleeve (2) and the shell (1) constitutes the vaporization zone (11). An oxidant inlet pipe (6) is vertically arranged inside the hydrogen-oxygen exothermic zone (10). One end of the oxidant inlet pipe (6) extends to the outside of the shell (1). A product outlet (5) is provided between the oxidant inlet pipe (6) and the shell (1). The product outlet (5) is an outer annular area coaxial with the oxidant inlet pipe (6) and the sleeve (2). The outer shell (1) of the gasification zone (11) is provided with a supercritical water inlet (3) and a coal-water slurry nozzle. The supercritical water inlet (3) is arranged along the tangential direction of the shell (1). The coal-water slurry nozzles are arranged in multiple rows from top to bottom along the shell (1). Each coal-water slurry nozzle includes four nozzles (4). The four nozzles (4) are arranged circumferentially along the shell (1). The angle between the nozzles (4) and the horizontal direction is 1~45°. A slag discharge area (12) is provided at the lower interior of the shell (1), and a slag discharge port (9) is provided at the bottom of the shell (1). The supercritical water inlet (3) is at the same height as the four nozzles (4) in the top row. The supercritical water inlet (3) is set directly opposite the outlet of any of the nozzles (4) in the top row and is perpendicular to the corresponding nozzle (4). The outer side of the sleeve (2) is provided with a first spiral guide vane (7), and the inner side of the shell (1) is provided with a second spiral guide vane (8). The first spiral guide vane (7) and the second spiral guide vane (8) are one or more spiral linear vanes. The first spiral guide vane (7) and the second spiral guide vane (8) are provided with 4 to 6 layers on both the sleeve (2) and the shell (1). The angle between the first spiral guide vane (7) and the second spiral guide vane (8) and the horizontal plane is 45 to 60°.
2. The multi-jet coal water slurry supercritical water gasification reactor according to claim 1, wherein, The shell (1), the hydrogen-oxygen exothermic zone (10) and the vaporization zone (11) are all equipped with corresponding thermocouples.
3. The multi-jet coal water slurry supercritical water gasification reactor according to claim 1, wherein, The sleeve (2), product outlet (5) and oxidant inlet pipe (6) are coaxially arranged.