A semi-closed structure of a boiler and a method for designing the same

Abstract

A boiler semi-tight enclosing structure is extended upward from the middle position of the boiler along the up-down direction of the boiler to form an enclosing structure; the semi-tight enclosing structure surrounds the instruments and meters, the desuperheating water system and the boiler drum above the middle position; the semi-tight enclosing structure comprises support columns rooted on the boiler steel structure for fixing the semi-tight enclosing structure on the boiler; the semi-tight enclosing structure is rooted on the original steel structure of the boiler and extended upward from the middle position, which not only ensures the firm connection between the semi-tight structure and the boiler, but also saves a large amount of building materials, and meanwhile, in severe cold weather, the heat loss of the enclosing structure to the outside is reduced, the temperature in the enclosing structure is increased, the condensation of the desuperheating water in severe cold weather and the malfunction of the instruments and meters due to too low temperature are avoided, and the safe operation of the unit is ensured.

Description

Technical Field

[0001] This invention relates to the field of boilers, and in particular to a semi-closed structure for a boiler and its design method. Background Technology

[0002] In warmer climates, power boiler roof platforms are typically designed with an open top to enhance heat dissipation and reduce costs. Some roof piping systems, such as closed cooling water systems, and instruments are exposed outside the roof platform. In extremely cold weather, these pipes and instrument measuring points are prone to freezing, which can cause the generator set to fail to start or even trip.

[0003] In regions with extremely cold climates, the boiler's ability to withstand frigid weather is considered before construction. Therefore, during design and construction, a closed insulation structure extends directly from the ground to the boiler roof, placing the entire boiler within this structure. However, due to land constraints in industrial plants and strict space limitations between the boiler and other buildings, this method is not suitable for existing open boiler platforms. Furthermore, the fully enclosed boiler structure also suffers from drawbacks such as high material consumption, long construction periods, and poor ventilation. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the technical problem to be solved by the present invention is to provide a semi-closed structure for a boiler and its design method.

[0005] This invention proposes a semi-closed structure for a boiler. Along the vertical direction of the boiler, the semi-closed structure extends upward from the middle position of the boiler to form a closed structure. The semi-closed structure surrounds the instruments, desuperheating water system, and boiler drum located above the middle position. The semi-closed structure includes a support column, which is rooted in the steel structure of the boiler and used to fix the closed structure to the boiler.

[0006] Preferably, the support column is welded to the upright column of the boiler body without damage.

[0007] Preferably, ventilation holes are provided at the bottom and on the side walls of the semi-closed structure.

[0008] Preferably, a downpipe is also provided, which is connected to the enclosed roof structure and is used to guide the accumulated water on the enclosed roof structure.

[0009] Preferably, the semi-enclosed structure includes a lighting system for internal lighting of the enclosed structure.

[0010] Preferably, the semi-enclosed structure includes a frame and an enclosure. The frame includes the support columns installed on the boiler steel structure. The enclosure includes brackets, purlins, and enclosure panels. The brackets and purlins are welded to the frame to support the enclosure panels.

[0011] A design method for a semi-enclosed structure of a boiler includes the following steps: 1) Determining the area surrounding the boiler by the semi-enclosed structure according to the required antifreeze instruments, desuperheating water system, and steam drum location; 2) Determining the anchoring location and number of anchors for the semi-enclosed structure based on the area surrounding the semi-enclosed structure, its weight, basic wind pressure, and ultimate seismic intensity; 3) Checking the pressure borne by the columns supporting the semi-enclosed structure to ensure that the stress borne by the columns does not exceed the allowable ratio of 0.95; 4) Constructing the semi-enclosed structure.

[0012] As described above, the present invention relates to a semi-enclosed structure for a boiler. This semi-enclosed structure is rooted in the original steel structure of the boiler and extends upward from the middle position. This not only ensures a firm connection between the semi-enclosed structure and the boiler, but also saves a large amount of building materials. At the same time, in cold weather, it can reduce the heat loss of the enclosed structure, increase the temperature inside the enclosed structure, and prevent the condensation of the cooling water and the malfunction of instruments due to low temperature in cold weather, thus ensuring the safe operation of the unit. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a boiler with a semi-closed structure installed according to the present invention.

[0014] Figure 2 This is another schematic diagram of the boiler with a semi-closed structure installed according to the present invention.

[0015] Explanation of reference numerals in the attached figures:

[0016] 100. Boiler; 110. Column; 200. Semi-closed structure; 210. Support column; 220. Enclosure panel; 221. Roof; 222. Side wall. Detailed Implementation

[0017] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0018] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0019] like Figure 1 and Figure 2 As shown, an embodiment of a semi-closed structure for a boiler is provided. The semi-closed structure 200 extends upward from the middle position of the boiler 100 to form a closed structure. The semi-closed structure 200 surrounds boiler equipment such as instruments, desuperheating water system, and boiler drum located above the middle position. The semi-closed structure 200 includes a support column 210, which is rooted in the steel structure of the boiler 100 and used to fix the semi-closed structure 200 to the boiler 100.

[0020] The aforementioned vertical direction refers to the height of the boiler. The aforementioned intermediate position refers to the semi-enclosed structure 200 extending upwards from the boiler platform, not from the ground. The specific number of boiler platform layers is not limited; it can be determined based on the specific area to be enclosed by the semi-enclosed structure 200. Specifically, it is defined by the location of boiler equipment requiring antifreeze protection, such as instruments, desuperheating water systems extending outside the plant and located on the boiler platform, and the boiler drum. It should be noted that to achieve the semi-enclosed nature of the boiler, the boiler's support columns 210 are directly anchored to the original steel structure of the boiler 100, thus fixing the enclosed structure to the boiler's position.

[0021] This semi-enclosed structure 200 is rooted in the original steel structure of the boiler and extends upwards from the middle. This ensures a secure connection between the semi-enclosed structure and the boiler while saving significant amounts of building materials. Especially for large boilers, the material savings compared to a fully enclosed structure can often be tens of tons. Furthermore, because the semi-enclosed structure encloses instruments, the desuperheating water system, the boiler drum, and other boiler equipment requiring freeze protection, it reduces heat loss from the enclosed structure in cold weather, increasing the internal temperature and preventing condensation of the desuperheating water and instrument malfunction due to low temperatures, thus ensuring the safe operation of the unit.

[0022] The support column 210 is welded non-destructively to the boiler body column 110. Since the semi-closed structure 200 covers the boiler body in the front-to-back and left-to-right directions, the anchoring point of the support column 210 on the column 110 can be selected according to the distribution of the semi-closed structure 200 and the boiler body column 110, ensuring that the boiler body column 110 supports the weight of the semi-closed structure 200 under equal load. Non-destructive welding ensures the connection strength of the support column 210 to the boiler body column 110.

[0023] The bottom and side walls 222 of the tight-fitting enclosed structure are provided with openable and closable ventilation holes.

[0024] When the ambient temperature rises, the temperature inside the enclosed structure becomes significantly higher than the temperature outside. Excessive heat can negatively impact the normal operation of the equipment and the safety of boiler operators. Since the bottom wall of the semi-enclosed structure 200 is suspended in the middle of the boiler 100, ventilation holes can be created at the bottom of this structure, directly connecting the inside and outside. When the temperature inside the semi-enclosed structure 200 is high, the high-temperature gas inside flows upwards through the side wall of the semi-enclosed structure 200 and out of the chamber. Meanwhile, cooler outside air can directly enter the enclosed structure through the ventilation holes in the bottom wall of the semi-enclosed structure 200, achieving natural air circulation and reducing the temperature inside the enclosed structure.

[0025] Preferably, the semi-enclosed structure is also equipped with a downpipe that connects to the ceiling 221 of the enclosed structure to guide accumulated water on the ceiling. A lighting system is also provided to supplement the lighting inside the enclosed structure.

[0026] A design method for a semi-enclosed structure of a boiler includes the following steps: 1) Determine the area surrounding the boiler by the semi-enclosed structure according to the required antifreeze boiler equipment, instruments, and desuperheating water system; 2) Determine the anchoring location and number of anchors for the boiler based on the area surrounding the semi-enclosed structure, its weight, basic wind pressure, and ultimate seismic intensity; 3) Check the columns supporting the semi-enclosed structure to ensure that the stress borne by the columns does not exceed 0.95 of the allowable ratio; 4) Construct the semi-enclosed structure.

[0027] In this embodiment, the boiler equipment, instruments, desuperheating water system, and steam drum that require freeze protection on the furnace top platform are located above the 30m platform above the furnace top. Therefore, the height direction of the furnace top enclosure range is determined to be from 1m below the 30mm platform above the furnace top to the position of the furnace top canopy at the highest point of the boiler. The existing canopy covering the boiler can be used as the roof of the enclosure structure to seal the perimeter and bottom of the area to be enclosed, with the side walls connected to the canopy after enclosure. Of course, in actual engineering, the canopy can also be removed directly.

[0028] In this embodiment, since the boiler columns covered by the semi-enclosed structure are approximately columns K5, K6, K7, K8, K9, K10, and K11, the anchoring position of the semi-enclosed structure can be determined on these columns 110. Furthermore, based on the semi-enclosed structure's weight of 40t and its ability to withstand a basic wind pressure of 0.55kN / m³,... 2 (According to GB50009-2012) Seismic intensity 7 degrees, acceleration 0.1g (according to GB50011-2010), determine the specific rooting location. The specific calculation steps are roughly the same as those for adding loads to a boiler during boiler modification, and are therefore not described in detail here as they are existing technology.

[0029] The columns supporting the semi-closed structure are checked to ensure that the stress borne by the columns does not exceed the allowable ratio of 0.95. The loads borne by columns K5, K6, K7, K8, K9, K10, and K11 can be calculated separately. Specifically, the boiler steel structure model after the addition of the semi-closed structure can be checked using STAAD software model calculations according to the "Code for Design of Steel Structures of Boilers" GB / T22395-2008. It is ensured that the actual stress ratio of each node of each column does not exceed the allowable ratio of 0.95, and that the actual stress ratio meets the requirements.

[0030] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A design method for a semi-closed structure of a boiler, characterized in that, Along the vertical direction of the boiler (100), the semi-closed structure (200) extends upward from the middle position of the boiler (100) to form a closed structure; the semi-closed structure (200) surrounds the instruments, meters, desuperheating water system and boiler drum located above the middle position that need to be protected from freezing; the semi-closed structure (200) includes a support column (210), which is rooted in the steel structure of the boiler (100) and used to fix the semi-closed structure (200) to the boiler (100); the support column is welded to the column (110) of the boiler (100) without damage; ventilation holes are provided on the bottom wall and side wall (222) of the semi-closed structure; a downpipe is also provided, which connects to the roof of the semi-closed structure and is used to guide the water accumulated on the roof (221) of the semi-closed structure; the semi-closed structure includes a frame and an enclosure, the frame The frame includes the support column (210) installed on the steel structure of the boiler (100); the enclosure includes brackets, purlins and enclosure panels, the brackets and purlins are welded to the frame to support the enclosure panels (220); the design method includes the following steps: 1) Determine the range of the semi-closed structure (200) surrounding the boiler (100) according to the required antifreeze instruments, desuperheating water system and boiler drum location; 2) Determine the rooting position and number of the semi-closed structure (200) according to the surrounding range of the semi-closed structure (200), the weight of the semi-closed structure (200), the basic wind pressure it can withstand and the ultimate seismic intensity it can withstand; 3) Check the pressure borne by the column (110) supporting the semi-closed structure (200) to ensure that the stress borne by the column (110) does not exceed the allowable ratio of 0.95; 4) Construct the semi-closed structure.

2. The design method for a semi-closed structure of a boiler according to claim 1, characterized in that, A lighting system is also provided for the internal lighting of the semi-closed structure.

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