Water-cooled wall lining and radiation waste boiler and gasifier containing the same

Abstract

The present invention discloses a water-cooled wall lining and a radiation waste boiler and a gasifier containing the same. The water-cooled wall lining includes a cylindrical water-cooled wall, which is circumferentially arranged to form a radiation waste boiler chamber; multiple groups of heat exchange units, which are arranged in the radiation waste boiler chamber and distributed circumferentially; each group of heat exchange units includes a finned water-cooled wall I and at least one group of finned water-cooled wall II; the finned water-cooled wall I is distributed along the central axis direction from the cylindrical water-cooled wall to the radiation waste boiler chamber; the finned water-cooled wall II is circumferentially arranged and intersected with the finned water-cooled wall I. The water-cooled wall lining provided by the present invention can effectively reduce the height of the waste boiler and the gasifier under the same heat exchange capacity, and at the same time effectively reduce the dust accumulation on the water-cooled wall, and improve the long-term operation efficiency of the water-cooled wall.

Description

Technical Field

[0001] The invention relates to a water-cooled wall lining and a radiation waste boiler and a gasification furnace containing the same. Background Art

[0002] Coal remains a vital energy source and raw material in my country. In recent years, my country's modern coal chemical industry has experienced rapid growth. Clean and efficient coal utilization technologies, exemplified by entrained-flow coal gasification, are core and leading technologies in the development of this industry. my country has made significant progress in basic research, technological development, engineering demonstration, and application of coal gasification technologies. Large-scale coal gasification technologies, such as multi-nozzle opposed water-coal slurry gasification, have been developed to meet the diverse gasification technology needs of coal chemical products and play a significant role in ensuring national energy security.

[0003] Entrained-flow coal gasification technology primarily includes chilled, depleted-boiler, and combined depleted-boiler-chilled (also known as semi-depleted-boiler) processes. The chilled process is the most widely used and requires minimal equipment investment. Because the high-temperature syngas produced by the gasifier has a high moisture content after chilling, it can meet the steam requirements for full-shift conversion. This process is primarily used in industries such as coal-to-ammonia and coal-to-hydrogen. The depleted-boiler process offers high energy efficiency, fully recovering the heat of the high-temperature syngas through radiant and convection depleted boilers located at the gasifier's combustion chamber outlet. However, due to its large size and complexity, its initial investment is relatively high, and it is primarily used in industries such as IGCC power generation. The development of semi-depleted-boiler gasification technology lies somewhere between the chilled and depleted-boiler processes, improving energy efficiency while minimizing equipment investment. It is particularly suitable for industries employing partial-shift conversion processes, such as coal-to-methanol and coal-to-liquids (FT-C) synthesis, as well as the power industry, and holds broad application prospects.

[0004] Currently, domestically developed semi-waste boiler gasification technologies, such as the multi-nozzle opposed coal gasification technology and the Jinhua furnace gasification technology, have completed engineering demonstrations. In addition to the problems of ash and slagging on the water-cooled wall surfaces, semi-waste boiler gasifiers also face operational limitations. The large size and height of the radiant waste boiler are also drawbacks, contributing to the increased investment in this type of equipment. Compared to traditional quenched gasifiers, semi-waste boiler gasifiers are essentially split between the gasification / combustion chamber and the quenching chamber, with the radiant waste boiler added to the center. This results in a three-part structure consisting of the gasification / combustion chamber, the radiant waste boiler, and the quenching chamber. For example, a single-furnace gasifier capable of processing 2,000 tons of coal per day would be approximately 20 meters taller than a quenched process, increasing the height of the gasification frame accordingly. This increases the construction costs of both the gasifier and the frame. Further reducing the height of the equipment while ensuring effective heat recovery would be crucial for enhancing the competitive advantage of this technology.

[0005] Adding water-cooled walls inside a radiant waste boiler to increase the heat exchange area per unit volume and enhance heat transfer efficiency is relatively easy for those skilled in the art. However, the addition of water-cooled walls reduces the spacing between the walls, which can easily lead to dust accumulation, slag, and bridging, which can affect the long-term heat transfer efficiency of the radiant waste boiler. There is an urgent need to develop a water-cooled wall structure that can enhance heat transfer efficiency, reduce the height of the waste boiler, and reduce dust accumulation and other issues. Summary of the Invention

[0006] The present invention addresses the technical problem of overcoming the shortcomings of existing semi-waste boiler gasifiers, such as low heat recovery efficiency per unit volume, large equipment size, high height, and susceptibility to dust accumulation on the water-cooled walls, which reduces heat exchange efficiency. The present invention provides a water-cooled wall lining and a radiant waste boiler and gasifier incorporating the same. While maintaining the same heat exchange capacity, the water-cooled wall lining can effectively reduce the height of the waste boiler and gasifier, while also effectively reducing dust accumulation on the water-cooled walls and improving their long-term operating efficiency.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a water-cooled wall lining, comprising:

[0009] The water-cooled wall of the cylinder is arranged circumferentially to form a radiant waste boiler chamber;

[0010] A plurality of heat exchange units are arranged in the radiant waste boiler chamber and distributed along the circumferential direction;

[0011] Each group of the heat exchange units includes a finned water wall I and at least one group of finned water wall II;

[0012] The finned water-cooled wall I is distributed along the central axis from the cylindrical water-cooled wall to the radiant waste boiler chamber;

[0013] The fin water-cooling wall II is circumferentially arranged and intersects with the fin water-cooling wall I;

[0014] The distance X1 between the front end of the finned water wall I and the central axis is D1-2D1, where D1 is the diameter of the synthesis gas inlet, and the "front end" refers to the end close to the central axis;

[0015] The distance X2 between the front ends of two adjacent groups of the finned water-cooling walls I is greater than 300 mm;

[0016] In two adjacent groups of the heat exchange units, the circumferential spacing X3 between the two groups of the finned water-cooled walls II arranged at the front end is greater than 200 mm.

[0017] In the present invention, the cylindrical water-cooling wall may be conventional in the art, and preferably comprises a plurality of water-cooling tubes, with two adjacent water-cooling tubes connected by ribs.

[0018] In the present invention, the spacing X1 is preferably 1.2D1-1.8D1, such as 1.3D1, 1.4D1, 1.5D1 or 1.6D1, more preferably 1.5D1.

[0019] After long-term experimental exploration, the inventors of the present invention found that when the spacing X1 is within the above range, the probability of ash in the synthesis gas colliding with the finned water-cooled wall I is greatly reduced. At the same time, it can also effectively utilize the space in the radiation waste boiler chamber, increase the heat exchange area per unit volume, and improve the heat exchange efficiency.

[0020] Those skilled in the art will appreciate that the degree of ash accumulation at the front end of the finned water-cooled wall I is not only directly related to the spacing X1, but also to the ash particle size. Ash particles with smaller particle sizes (e.g., less than 30 μm) have better airflow followability and are more easily dispersed throughout the furnace of the radiant waste boiler. Ash particles with larger particle sizes (e.g., greater than 200 μm) are concentrated in the central flow channel due to gravity, causing less noticeable slag erosion of the finned water-cooled wall I.

[0021] In the present invention, the structure of the finned water-cooled wall I can be conventional in the art, and is generally composed of a plurality of water-cooling tubes arranged at equal intervals.

[0022] The distance between two adjacent water-cooling tubes may be conventional in the art.

[0023] When the finned water-cooled wall I is composed of a plurality of water-cooling tubes arranged at equal intervals, the number of the water-cooling tubes may be 1 to 12, preferably 5 to 10, such as 6, 7, 8 or 9.

[0024] The outer diameter of the water-cooling pipe may be conventional in the art, generally 20 to 100 mm, such as 32 mm, 38 mm, 45 mm, 57 mm or 76 mm.

[0025] In the present invention, the spacing X2 is preferably 300-900 mm, more preferably 400-800 mm, such as 450 mm, 500 mm, 550 mm, 600 mm, 650 mm or 700 mm.

[0026] After long-term experimental research, the inventors found that when the spacing X2 is within the above range, slagging, bridging or blockage is unlikely to occur between two adjacent groups of the fin water-cooled walls I. At the same time, the space in the radiation waste boiler chamber can be fully utilized, and several groups of fin water-cooled walls I can be set up to increase the heat exchange area and improve the heat exchange efficiency.

[0027] In the present invention, the spacing X3 is preferably 200-500 mm, more preferably 300-500 mm, such as 350 mm, 400 mm or 450 mm.

[0028] Similarly, when the spacing X3 is within the range defined by the present invention, slagging, bridging or blockage is unlikely to occur between the finned water-cooled walls II in two adjacent groups of the heat exchange units, while the furnace space can be fully utilized.

[0029] In the present invention, in the same heat exchange unit, the distance X4 between the front end of the fin water-cooled wall II and the fin water-cooled wall I can be 0 to 250 mm, preferably 50 to 160 mm, for example 72 mm, 91 mm or 144 mm. When the heat exchange unit includes multiple groups of fin water-cooled walls II, the distance X4 refers to the distance between the fin water-cooled wall II and the fin water-cooled wall I arranged at the front end.

[0030] The finned water wall II provided in the present invention increases the heat exchange area per unit volume while also allowing ash from the syngas to preferentially deposit on the front finned water wall II, effectively reducing dust accumulation on the subsequent water walls. However, if the finned water wall II is positioned too far forward, dust accumulation on its surface will increase, which is detrimental to the long-term operation of the water wall.

[0031] In the present invention, in a single heat exchange unit, the number of groups of the finned water-cooled wall II is preferably multiple, more preferably 2 to 4, for example, 3.

[0032] In the present invention, in a single heat exchange unit, when there are multiple groups of the finned water-cooled wall II, the spacing X5 between two adjacent groups of the finned water-cooled wall II can be 60mm≤X5≤400mm, for example, 144mm, 216mm, 288mm or 360mm.

[0033] If the spacing X5 is set too small, slagging, bridging or blockage may easily occur between two adjacent groups of fin water-cooled walls in the same heat exchange unit. If the spacing X5 is set too large, the number of fin water-cooled walls will be affected, which will affect the heat exchange area. The spacing X5 in the present invention is an optimal range obtained by the inventors by comprehensively considering the heat exchange area and reducing dust accumulation.

[0034] Based on the technical solution of the present invention, the selected outer diameter of the water-cooling tube and the gap between conventional water-cooling tubes, those skilled in the art can reasonably design the number of groups of the heat exchange units and the number of water-cooling tubes of the finned water-cooling wall I and the finned water-cooling wall II, thereby arranging the water-cooled wall lining of the present invention.

[0035] In the present invention, the support method of the finned water-cooled wall I and the finned water-cooled wall II can be conventional in the field. Preferably, the water-cooling pipes of the finned water-cooled wall I penetrate into the radiation waste boiler chamber through the cylindrical water-cooled wall and are vertically supported on the wall surface of the cylindrical water-cooled wall; the water-cooling pipes of the finned water-cooled wall II penetrate into the radiation waste boiler chamber through the top of the cylindrical water-cooled wall and are downwardly supported on the upper part of the cylindrical water-cooled wall.

[0036] The supporting method of the finned water-cooling wall I and the finned water-cooling wall II of the present invention can avoid the expansion effect between the water-cooling tubes caused by the drastic change of high-temperature heat load.

[0037] The present invention also provides a radiation waste boiler comprising the water-cooled wall lining.

[0038] The present invention also provides a gasifier comprising the above-mentioned radiation waste boiler.

[0039] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0040] The positive progress effect of the present invention is:

[0041] (1) Under the same heat exchange requirements, the water-cooled wall lining of the present invention can significantly reduce the height of the radiation waste boiler, the height of the corresponding frame, and the height of the gasifier, thereby reducing the total investment of the device and improving the installation stability and safety of the gasifier;

[0042] (2) Reduce the influence of dust and slagging on the surface of the water-cooled wall lining on the heat exchange effect, and the heat exchange effect is good in long-term operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the water-cooled wall structure of Example 1;

[0044] Figure 2 This is a schematic diagram of the structure of the radiation waste pot in Example 1.

[0045] 1-Radiant waste boiler chamber; 2-Metal shell; 3-Synthesis gas inlet; 4-Synthesis gas outlet; 5-Cylinder water-cooled wall; 6-Finned water-cooled wall I; 7-Finned water-cooled wall II. DETAILED DESCRIPTION

[0046] The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. Experimental methods in the following examples where specific conditions are not specified were performed according to conventional methods and conditions, or selected according to the product specifications.

[0047] Example 1

[0048] Reference Figure 1 and Figure 2As shown, the diameter of the metal shell (2) of the radiation waste boiler is 6.0m, the height of the radiation waste boiler is 11.0m, the diameter of the cylindrical water-cooled wall (5) is 4.8m, and there are 16 heat exchange units, which are evenly arranged circumferentially in the radiation waste boiler chamber (1). In each group of heat exchange units, the number of water cooling tubes of the finned water-cooled wall I (6) is 6, and the number of water cooling tubes of the finned water-cooled wall II (7) is set in two rows, and the number of water cooling tubes in each row is 4. The size of the water cooling tubes is The diameter D1 of the synthesis gas inlet is 1.2 m, X1 is 1.5D1, and the values ​​of X1-X5 are shown in Table 1.

[0049] Example 2

[0050] The metal shell of the radiation waste boiler has a diameter of 5.0 m, a height of 14.0 m, and a cylindrical water-cooled wall diameter of 4.0 m. In each heat exchange unit, finned water-cooled wall I has five water-cooling tubes, while finned water-cooled wall II has one row and four water-cooling tubes per row. X1 is 1.34D1, and all other parameters and settings are the same as in Example 1. The values ​​of X1-X4 are shown in Table 1.

[0051] Comparative Example 1

[0052] The metal shell of the radiation waste boiler has a diameter of 4.2 m, a height of 21.0 m, and a cylindrical water-cooled wall diameter of 3.2 m. Each heat exchange unit has five water-cooling tubes in finned water-cooled wall I, and no finned water-cooled wall II is provided. X1 is equal to D1, and all other parameters and settings are the same as in Example 1. The values ​​of X1-X2 are shown in Table 1.

[0053] Effect embodiment

[0054] Reference Figure 2 As shown, the radiation waste boilers of Examples 1-2 and Comparative Example 1 were used to conduct heat exchange experiments on a chilled water-coal slurry gasifier with a daily coal processing capacity of 2,000 tons. The gasification pressure of the gasifier was 6.5 MPa, the gasification temperature was 1,300°C, and the synthesis gas (CO+H2) output was 135,000 Nm 3 / h. The 1300℃ high-temperature synthesis gas and ash generated in the gasification chamber enter the radiation waste boiler chamber (1) from the synthesis gas inlet (3). After heat exchange with the water-cooled wall, the temperature drops and the gas flows out from the synthesis gas outlet (4). The cooled synthesis gas enters the scrubbing cooling chamber, where the synthesis gas temperature drops to about 800℃. The water-gas ratio of the crude synthesis gas entering the conversion section is about 0.7. The feed water temperature of the drum boiler is 218℃ and the pressure is 11.57MPa. After heat exchange, the steam pressure at the drum is 11.07MPa, the steam temperature is 319℃, and the steam volume is 100t / h.

[0055] Table 1 Parameter settings of various embodiments and comparative examples

[0056]

[0057] As can be seen from Table 1, when the syngas processing capacity and the syngas inlet and outlet temperatures are the same, the heights of the radiation waste boilers in Examples 1 and 2 are significantly reduced compared to Comparative Example 1, among which the height of Example 1 is reduced by more than 50%, and the height of the waste boiler in Example 2 is reduced by 33% compared to Comparative Example 1.

Claims

1. A water-cooled wall lining, characterized in that: It includes: The water-cooled wall of the cylinder is arranged circumferentially to form a radiation waste boiler chamber; A plurality of heat exchange units, wherein the plurality of heat exchange units are arranged in the radiant waste boiler chamber and distributed along the circumferential direction; Each group of the heat exchange units includes a finned water-cooled wall I and at least one group of finned water-cooled wall II; The finned water-cooled wall I is distributed along the central axis direction from the barrel water-cooled wall to the radiation waste boiler chamber; The finned water-cooled wall II is arranged circumferentially and intersects with the finned water-cooled wall I; The distance X1 between the front end of the finned water-cooled wall I and the central axis is 1.2D1-1.8D1, wherein D1 is the diameter of the synthesis gas inlet, and the front end is the end close to the central axis; The front end spacing X2 between two adjacent groups of the finned water-cooled walls I is 300-900 mm; in two adjacent groups of the heat exchange units, the circumferential spacing X3 between the two groups of the finned water-cooled walls II arranged at the front end is 200-500 mm.

2. The water-cooled wall lining according to claim 1, characterized in that: The distance X1 is 1.3D1, 1.4D1, 1.5D1 or 1.6D1.

3. The water wall lining according to claim 2, characterized in that: The distance X1 is 1.5D1.

4. The water wall lining according to claim 1, characterized in that: The spacing X2 is 400-800 mm.

5. The water wall lining according to claim 4, characterized in that: The spacing X2 is 450mm, 500mm, 550mm, 600mm, 650mm or 700mm.

6. The water wall lining according to claim 1, characterized in that: The spacing X3 is 300-500 mm.

7. The water wall lining according to claim 6, characterized in that: The spacing X3 is 350 mm, 400 mm or 450 mm.

8. The water wall lining according to claim 1, characterized in that: In the same heat exchange unit, a distance X4 between the front ends of the finned water-cooled wall II and the finned water-cooled wall I is 0 to 250 mm.

9. The water wall lining according to claim 8, characterized in that: In the same heat exchange unit, a distance X4 between the front ends of the finned water-cooled wall II and the finned water-cooled wall I is 50 to 160 mm.

10. The water wall lining according to claim 9, characterized in that: In the same heat exchange unit, the distance X4 between the front end of the fin water-cooled wall II and the front end of the fin water-cooled wall I is 72 mm, 91 mm or 144 mm.

11. The water wall lining according to claim 1, characterized in that: The fin water-cooled wall II may be provided in multiple groups.

12. The water wall lining according to claim 1, characterized in that: The number of groups of the fin water-cooled wall II is 2 to 4.

13. The water wall lining according to claim 1, characterized in that: The number of groups of the finned water-cooled wall II is 3.

14. The water wall lining according to claim 1, characterized in that: In a single heat exchange unit, when there are multiple groups of the finned water-cooled wall II, the spacing X5 between two adjacent groups of the finned water-cooled wall II is 60 mm ≤ X5 ≤ 400 mm.

15. The water wall lining according to claim 14, characterized in that: The spacing X5 is 144 mm, 216 mm, 288 mm or 360 mm.

16. A radiation waste pot, characterized in that: It comprises the water-cooled wall lining according to any one of claims 1 to 15.

17. A gasifier, characterized in that: It includes the radiation waste pot as claimed in claim 16.

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