A gasification synthesis gas dust removal and sensible heat cascade utilization system

Abstract

The present invention discloses a gasification synthesis gas dust removal and sensible heat cascade utilization system, comprising: a radiation waste heat boiler, a first heat exchange component is installed on the inner wall of the radiation waste heat boiler; a distribution chamber, the inlet of the distribution chamber is connected to the outlet of the radiation waste heat boiler; a cyclone dust collector, the inlet of the cyclone dust collector is connected to the air outlet of the distribution chamber, and a second heat exchange component is installed on the inner wall of the cyclone dust collector; a first convection waste heat boiler, the inlet of the first convection waste heat boiler is connected to the air outlet of the cyclone dust collector, and a third heat exchange component is installed on the inner wall of the first convection waste heat boiler; a dust removal and cleaning device, the inlet of the dust removal and cleaning device is connected to the air outlet of the first convection waste heat boiler; and a second convection waste heat boiler, the inlet of the second convection waste heat boiler is connected to the outlet of the dust removal and cleaning device, and a fourth heat exchange component is installed on the inner wall of the second convection waste heat boiler.

Description

Technical Field

[0001] The present invention relates to the technical field of sensible heat recovery, and in particular to a gasification synthesis gas dust removal and sensible heat cascade utilization system. Background Art

[0002] Coal undergoes gasification reaction in the gasifier, and the product of the gasification reaction is high-temperature, high-pressure, dust-containing synthesis gas in a reducing atmosphere. Effectively recovering the physical sensible heat in the synthesis gas can greatly improve the thermal efficiency of the system, which is conducive to responding to the requirements of energy conservation and emission reduction.

[0003] Currently, there are three main types of sensible heat utilization systems for gasifiers in China. The first uses water quenching to cool the syngas temperature, which has the lowest sensible heat utilization rate. The second uses a radiation waste heat boiler combined with water quenching, which significantly improves the sensible heat utilization rate compared to water quenching. The third uses a radiation waste heat boiler combined with a convection waste heat boiler, which has the highest sensible heat utilization rate. However, the convection waste heat boiler in this structure is prone to ash accumulation and clogging. In addition, due to the gas characteristics of syngas, the flue gas temperature at the convection waste heat boiler outlet must be maintained at around 300°C to avoid low-temperature corrosion, which results in underutilization of the sensible heat of the syngas.

[0004] Invention content

[0005] The object of the present invention is to provide a gasification synthesis gas dust removal and sensible heat cascade utilization system, so that the convection waste heat boiler is not easily blocked by dust accumulation and the sensible heat utilization rate of the synthesis gas is improved.

[0006] The present invention specifically provides a gasification synthesis gas dust removal and sensible heat cascade utilization system, used in conjunction with a gasifier, comprising:

[0007] a radiation waste heat boiler, wherein the inlet of the radiation waste heat boiler is connected to the gas outlet of the gasifier, and a first heat exchange component is installed on the inner wall of the radiation waste heat boiler;

[0008] a distribution chamber, wherein the inlet of the distribution chamber is connected to the outlet of the radiation waste heat boiler, and a first ash tank is installed on the discharge port of the distribution chamber;

[0009] a cyclone dust collector, wherein the inlet of the cyclone dust collector is connected to the air outlet of the distribution chamber, a second ash tank is installed on the discharge port of the cyclone dust collector, and a second heat exchange component is installed on the inner wall of the cyclone dust collector;

[0010] a first convection waste heat boiler, wherein the inlet of the first convection waste heat boiler is connected to the air outlet of the cyclone dust collector, and a third heat exchange component is installed on the inner wall of the first convection waste heat boiler;

[0011] a dust removal and cleaning device, the inlet of the dust removal and cleaning device being in communication with the gas outlet of the first convection waste heat boiler; and

[0012] A second convection waste heat boiler, wherein the inlet of the second convection waste heat boiler is connected to the outlet of the dust removal and cleaning device, and a fourth heat exchange component is installed on the inner wall of the second convection waste heat boiler.

[0013] Furthermore, the first heat exchange assembly includes a first cylindrical membrane water-cooled wall and an airfoil screen water-cooled wall, and the inlet and outlet headers of the first cylindrical membrane water-cooled wall and the inlet and outlet headers of the airfoil screen water-cooled wall are independently arranged.

[0014] Furthermore, the air outlet of the distribution chamber is arranged to be inclined downward.

[0015] Furthermore, the cyclone dust collector includes an upper cylinder and a lower cone, and the second heat exchange component includes a second cylindrical membrane water-cooled wall and a conical membrane water-cooled wall, the second cylindrical membrane water-cooled wall is installed in the inner wall of the upper cylinder, and the conical membrane water-cooled wall is installed in the inner wall of the lower cone.

[0016] Furthermore, the second cylindrical membrane water-cooled wall and the conical membrane water-cooled wall are both provided with a wear-resistant and fire-resistant layer.

[0017] Furthermore, a first expansion joint and a second expansion joint are respectively installed on the inlet and the outlet of the cyclone dust collector.

[0018] Furthermore, the third heat exchange component includes a superheater, a first evaporator and an economizer. The superheater, the evaporator and the economizer are arranged at intervals from top to bottom and are connected in sequence. The synthesis gas and the heat exchange medium in the third heat exchange component are respectively located on the inner and outer sides of the third heat exchange component.

[0019] Furthermore, the fourth heat exchange component includes a second evaporator, and the synthesis gas and the heat exchange medium in the fourth heat exchange component are respectively located on the inner and outer sides of the fourth heat exchange component.

[0020] The beneficial effects of the present invention include: The system for catalytic syngas dust removal and sensible heat cascade utilization provides maximum sensible heat recovery from syngas, while also producing large amounts of high-pressure and low-pressure steam as byproducts, thereby improving the overall system's energy efficiency. Furthermore, through the design of the distribution chamber and cyclone dust collector, 85%-90% of the ash in the syngas is removed, reducing ash accumulation and blockage in the first and second convection waste heat boilers. Therefore, the system is highly suitable for recovering and removing sensible heat from high-temperature syngas. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the process structure of the present invention;

[0023] Figure 2 It is a structural diagram of a radiation waste heat boiler;

[0024] Figure 3 This is a structural diagram of the first convection waste heat boiler (water tube structure);

[0025] Figure 4 This is a structural diagram of the first convection waste heat boiler (fire tube structure);

[0026] Figure 5 This is a structural diagram of the second convection waste heat boiler (fire tube structure).

[0027] In the figure: 10-radiation waste heat boiler, 11-first cylindrical membrane water-cooled wall, 12-airfoil screen water-cooled wall, 20-distribution chamber, 21-first ash tank, 22-first valve, 30-cyclone dust collector, 31-second ash tank, 32-second valve, 33-upper cylinder, 34-lower cone, 35-second cylindrical membrane water-cooled wall, 36-conical membrane water-cooled wall, 37-first expansion joint, 38-second expansion joint, 40-first convection waste heat boiler, 41-superheater, 42-first evaporator, 43-economizer, 50-dust removal and cleaning device, 60-second convection waste heat boiler, 61-second evaporator, 71-first pipeline, 72-second pipeline, 73-third pipeline, 74-fourth pipeline. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0030] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0032] In the description of the embodiments of the present application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, or the orientation or positional relationship in which the product of the application is usually placed when in use. This is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] In the description of the embodiments of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0034] See also Figure 1-5 The present invention provides a technical solution: a system for dust removal and cascaded sensible heat utilization of gasified syngas, used in conjunction with a gasifier. The system includes a radiant waste heat boiler 10, a distribution chamber 20, a cyclone dust collector 30, a first convection waste heat boiler 40, a dust removal and cleaning device 50, and a second convection waste heat boiler 60.

[0035] The inlet of the radiation waste heat boiler 10 is communicated with the gas outlet of the gasifier, and a first heat exchange component is installed on the inner wall of the radiation waste heat boiler 10 .

[0036] The distribution chamber 20 is located below the radiant waste heat boiler 10. Its inlet is connected to the outlet of the radiant waste heat boiler 10. A first ash tank 21 is installed at the outlet of the distribution chamber 20. The first ash tank 21 is used to collect and store ash deposited in the distribution chamber 20. A first valve 22 is installed at the outlet of the first ash tank 21.

[0037] The inlet of the cyclone dust collector 30 is connected to the outlet of the distribution chamber 20 via a first pipe 71. A second ash tank 31 is mounted on the outlet of the cyclone dust collector 30. This second ash tank 31 is used to collect and store ash deposited in the cyclone separator. A second valve 32 is mounted on the outlet of the second ash tank 31. A second heat exchange assembly is mounted on the inner wall of the cyclone dust collector 30.

[0038] The inlet of the first convection waste heat boiler 40 is connected to the air outlet of the cyclone dust collector 30 via a second pipe 72 . A third heat exchange component is installed on the inner wall of the first convection waste heat boiler 40 .

[0039] The inlet of the dust removal and cleaning device 50 is connected to the air outlet of the first convection waste heat boiler 40 through a third pipe 73 .

[0040] The inlet of the second convection waste heat boiler 60 and the outlet of the dust removal and cleaning device 50 are connected through a fourth pipe 74 . A fourth heat exchange component is installed on the inner wall of the second convection waste heat boiler 60 .

[0041] The specific operating process is as follows: Syngas discharged from the gasifier's outlet enters the radiant waste heat boiler 10, where it undergoes a first heat exchange operation with the first heat exchange component within the radiant waste heat boiler 10. After this first heat exchange operation, the syngas enters the distribution chamber 20, where the ash in the syngas settles and falls into the first ash tank 21, thereby undergoing a first dust removal operation. After this first dust removal operation, the syngas enters the cyclone dust collector 30 through the first pipeline 71, where the ash in the syngas settles and falls into the second ash tank 31, thereby undergoing a second dust removal operation. Simultaneously, the syngas also undergoes a second heat exchange operation with the second heat exchange component within the cyclone dust collector 30. After this second heat exchange operation, the syngas temperature drops below 850°C, reducing the ash's cohesiveness and the ash content within the syngas to 85%-90%, thereby preventing subsequent wear and ash accumulation in the first and second convection waste heat boilers 40 and 60.

[0042] After the second heat exchange operation, the syngas enters the first convection waste heat boiler 40 through the second pipeline 72, undergoing a third heat exchange operation with the third heat exchange component within the first convection waste heat boiler 40. After the third heat exchange operation, the syngas reaches approximately 300°C. After the third heat exchange operation, the syngas enters the dust removal and cleaning device 50. After being cleaned, the clean syngas enters the second convection waste heat boiler 60, undergoing a fourth heat exchange operation with the fourth heat exchange component within the second convection waste heat boiler 60. After the fourth heat exchange operation, the syngas is cooled to approximately 200°C before being discharged and entering the downstream process system.

[0043] This system realizes the sensible heat cascade recovery and dry dust removal of synthesis gas through the design of the entire structural process, and maximizes the recovery of heat contained in the synthesis gas to improve the energy utilization efficiency of the entire system. It is very suitable for sensible heat recovery and dust removal of synthesis gas.

[0044] At the same time, through the design of the distribution chamber 20 and the cyclone dust collector 30, 85%-90% of the ash content in the synthesis gas can be removed, so that the first convection waste heat boiler 40 and the second convection waste heat boiler 60 are not easily clogged by dust accumulation. Therefore, this system is very suitable for high-temperature synthesis gas sensible heat recovery and dust removal of gasified synthesis gas. Dry dust removal saves water and realizes dust-free recovery and utilization of synthesis gas.

[0045] In one embodiment, the first heat exchange assembly includes a first cylindrical membrane water-cooled wall 11 and an airfoil screen water-cooled wall 12 , and the inlet and outlet headers of the first cylindrical membrane water-cooled wall 11 and the inlet and outlet headers of the airfoil screen water-cooled wall 12 are independently arranged.

[0046] The first cylindrical membrane water-cooled wall 11 and the airfoil screen water-cooled wall 12 are two independent circulation systems. In the radiation waste heat boiler 10, the synthesis gas undergoes the first heat exchange operation with the first heat exchange component, and the synthesis gas can be fully cooled. At the same time, the cooling water in the first cylindrical membrane water-cooled wall 11 and the airfoil screen water-cooled wall 12 can produce a large amount of high-pressure saturated steam as a by-product after absorbing heat.

[0047] In one embodiment, the air outlet of the distribution chamber 20 is arranged to be inclined downward.

[0048] In one embodiment, the cyclone dust collector 30 includes an upper cylinder 33 and a lower cone 34, and the second heat exchange component includes a second cylindrical membrane water-cooled wall 35 and a conical membrane water-cooled wall 36. The second cylindrical membrane water-cooled wall 35 is installed on the inner wall of the upper cylinder 33, and the conical membrane water-cooled wall 36 is installed on the inner wall of the lower cone.

[0049] In the cyclone dust collector 30, the syngas undergoes a second heat exchange operation with the second heat exchange assembly, effectively cooling the syngas. Simultaneously, the cooling water within the second cylindrical membrane water-cooled wall 35 and the conical membrane water-cooled wall 36 absorbs heat, producing a large amount of medium-pressure saturated steam as a by-product. Furthermore, the cyclone dust collector 30 separates the syngas into gas and solids, and the ash in the syngas falls along the inner wall of the cyclone dust collector 30 into the second ash tank 31. This system combines dust removal and heat absorption functions, improving heat exchange efficiency and reducing equipment size.

[0050] In one embodiment, the second cylindrical membrane water-cooled wall 35 and the conical membrane water-cooled wall 36 are both coated with a wear-resistant and fire-resistant layer to improve the heat resistance of the cyclone dust collector 30 .

[0051] In one embodiment, a first expansion joint 37 and a second expansion joint 38 are respectively installed on the inlet and the outlet of the cyclone dust collector 30 to compensate for additional stress caused by temperature difference and mechanical vibration.

[0052] In one embodiment, the third heat exchange component includes a superheater 41, a first evaporator 42 and an economizer 43. The superheater 41, the evaporator and the economizer 43 are arranged at intervals from top to bottom and are connected in sequence. The synthesis gas and the heat exchange medium in the third heat exchange component are respectively located on the inner and outer sides of the third heat exchange component.

[0053] The heat exchange medium in the third heat exchange component is cooling water, which can produce a large amount of low-pressure saturated steam as a by-product after absorbing heat.

[0054] The third heat exchange component can be a water tube structure (ie, the outside of the tube is synthesis gas, and the inside of the tube is cooling water), or a fire tube structure (ie, the inside of the tube is synthesis gas, and the outside of the tube is cooling water).

[0055] In one embodiment, the fourth heat exchange component includes a second evaporator 61 , and the synthesis gas and the heat exchange medium in the fourth heat exchange component are respectively located at the inner and outer sides of the fourth heat exchange component.

[0056] The heat exchange medium in the fourth heat exchange component is cooling water, and the fourth heat exchange component adopts a fire tube structure (ie, the inside of the tube is synthesis gas, and the outside of the tube is cooling water).

[0057] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A gasification synthesis gas dust removal and sensible heat cascade utilization system, used in conjunction with a gasifier, characterized by: include: a radiation waste heat boiler, wherein the inlet of the radiation waste heat boiler is connected to the gas outlet of the gasifier, and a first heat exchange component is installed on the inner wall of the radiation waste heat boiler; a distribution chamber, wherein the inlet of the distribution chamber is connected to the outlet of the radiation waste heat boiler, and a first ash tank is installed on the discharge port of the distribution chamber; a cyclone dust collector, wherein the inlet of the cyclone dust collector is connected to the air outlet of the distribution chamber, a second ash tank is installed on the discharge port of the cyclone dust collector, and a second heat exchange component is installed on the inner wall of the cyclone dust collector; The inlet and the outlet of the cyclone dust collector are respectively provided with a first expansion joint and a second expansion joint; The cyclone dust collector includes an upper cylinder and a lower cone, the second heat exchange assembly includes a second cylindrical membrane water-cooled wall and a conical membrane water-cooled wall, the second cylindrical membrane water-cooled wall is installed in the inner wall of the upper cylinder, and the conical membrane water-cooled wall is installed in the inner wall of the lower cone; a first convection waste heat boiler, wherein the inlet of the first convection waste heat boiler is connected to the air outlet of the cyclone dust collector, and a third heat exchange component is installed on the inner wall of the first convection waste heat boiler; a dust removal and cleaning device, wherein the inlet of the dust removal and cleaning device is in communication with the gas outlet of the first convection waste heat boiler; and a second convection waste heat boiler, wherein the inlet of the second convection waste heat boiler is connected to the outlet of the dust removal and cleaning device, and a fourth heat exchange component is installed on the inner wall of the second convection waste heat boiler.

2. The gasification synthesis gas dust removal and sensible heat cascade utilization system according to claim 1, characterized in that: The first heat exchange assembly includes a first cylindrical membrane water-cooled wall and an airfoil screen water-cooled wall. The inlet and outlet headers of the first cylindrical membrane water-cooled wall and the inlet and outlet headers of the airfoil screen water-cooled wall are independently arranged.

3. The gasification synthesis gas dust removal and sensible heat cascade utilization system according to claim 1, characterized in that: The air outlet of the distribution chamber is arranged to be inclined downward.

4. The gasification synthesis gas dust removal and sensible heat cascade utilization system according to claim 1, characterized in that: The second cylindrical membrane water-cooled wall and the conical membrane water-cooled wall are both provided with a wear-resistant and fire-resistant layer.

5. The gasification synthesis gas dust removal and sensible heat cascade utilization system according to claim 1, characterized in that: The third heat exchange component includes a superheater, a first evaporator and an economizer. The superheater, the evaporator and the economizer are arranged at intervals from top to bottom and are connected in sequence. The synthesis gas and the heat exchange medium in the third heat exchange component are respectively located on the inner and outer sides of the third heat exchange component.

6. The gasification synthesis gas dust removal and sensible heat cascade utilization system according to claim 1, characterized in that: The fourth heat exchange component includes a second evaporator, and the synthesis gas and the heat exchange medium in the fourth heat exchange component are respectively located at the inner and outer sides of the fourth heat exchange component.

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