An ultra-low leakage desulfurization rotary heat exchanger system

Abstract

The application discloses a kind of ultra-low leakage desulfurization rotary heat exchanger systems, comprising: flue gas reheater, sealing purging system and air curtain purging system.The flue gas reheater includes rotor and shell, the rotor is composed of several support bodies, the support body is equipped with U-shaped piece, and the U-shaped piece is equipped with heat exchange element;The sealing purging system includes sealing fan and low-leakage air inlet piece, the sealing fan introduces high-pressure gas into the cavity of shell and rotor and forms high-pressure environment, the air curtain purging system includes purging fan and purging air pipe, the purging air pipe is fixed below the flue gas reheater, the purging air pipe is equipped with several strip-shaped air holes, and the purging fan blows out high-pressure gas through the strip-shaped air holes and forms air curtain from bottom to top.Adopting the application can effectively reduce the leakage rate of flue gas reheater, and reduce the power consumption when flue gas reheater operates.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power plant equipment, in particular to a desulfurization rotary heat exchanger system with ultra-low leakage. BACKGROUND

[0002] The flue gas reheater is widely used in the desulfurization field of domestic thermal power plants. Its function is to heat the clean flue gas after desulfurization, so that the exhaust gas temperature is above the dew point, reducing the corrosion of the flue and chimney, and improving the diffusion of pollutants. At the same time, it reduces the flue gas temperature entering the absorption tower, and reduces the process technology requirements for corrosion resistance in the tower. At present, the flue gas reheater used in domestic power plants has the problem of poor sealing effect and cross leakage of raw flue gas and clean flue gas, which greatly affects the efficiency of desulfurization, and even leads to the situation that the flue gas emission of the power plant does not meet the standard.

[0003] Another major problem is that when the flue gas reheater rotates, the flue gas passes through the end face of the flue gas reheater and is cooled by the heat dissipation element. However, the existing flue gas reheater is fixed by arranging a whole steel bar or steel strip inside the grid to fix the heat exchange element. These large-area fixed components reduce the contact area of the flue gas with the flue gas reheater, thereby affecting the absorption efficiency of the flue gas reheater and the heat dissipation capacity of the flue gas reheater. In addition, since the existing heat exchange element is mostly in a diagonal plate type or a corrugated plate type, using the above two types of plates will cause many problems, such as: large resistance of flue gas during circulation, easy to block ash at the turning point, difficult to clean, and other traditional shortcomings. SUMMARY

[0004] In order to solve the above technical problems, the present application provides a desulfurization rotary heat exchanger system with ultra-low leakage, which comprises a flue gas reheater, a sealing purge system and a wind curtain purge system.

[0005] The flue gas reheater comprises a shell and a rotor, the shell is arranged outside the rotor, the shell has a cavity inside, the rotor comprises a plurality of support bodies, a U-shaped piece and a heat exchange element, the support body is divided into a plurality of grids by a radial baffle and a circumferential baffle, the U-shaped piece is arranged at the lower part of the inner side of the support body, and the heat exchange element is placed in the grid through the support of the U-shaped piece.

[0006] The sealing purge system comprises a sealing fan and a low-leakage air inlet piece, the low-leakage air inlet piece is in conductive connection with the cavity, and the sealing fan blows high-pressure gas into the cavity through the low-leakage air inlet piece to form a high-pressure environment.

[0007] The wind curtain blowing system comprises a blowing fan and a blowing air pipe fixed below the flue gas reheater, wherein a plurality of strip-shaped air holes are arranged on the blowing air pipe, the blowing fan is in conductive connection with the blowing air pipe, and high-pressure gas is blown to the flue gas reheater through the strip-shaped air holes to form a wind curtain from bottom to top.

[0008] The heat exchange element comprises first heat exchange fins, second heat exchange fins and an element support, the first heat exchange fins and the second heat exchange fins are alternately arranged and fixed to form the heat exchange element through the element support.

[0009] The cross section of the first heat exchange fin is a wave-shaped enamel sheet plate, the cross section of the second heat exchange fin is composed of a plurality of continuous cross section segments, the cross section segments comprise S-shaped curved segments and straight segments, the first heat exchange fins and the second heat exchange fins are alternately arranged, and a plurality of straight-through gaps of large channels are formed between the first heat exchange fins and the second heat exchange fins.

[0010] The U-shaped piece 2 is made of Corten steel, the thickness of the U-shaped piece is 8-15 mm, the length is 80-110 mm, and the width is 40-50 mm.

[0011] The low-leakage air inlet piece is composed of an inlet part, a contraction part and an outlet part which are sequentially welded, and the low-leakage air inlet piece has a whole shape of a horn taper.

[0012] The cross section shape of the strip-shaped air hole is a rectangle, and the width of the rectangle is 2-7 cm.

[0013] The embodiment of the present application has the following beneficial effects:

[0014] 1. The heat exchange element is fixed by the U-shaped piece and other fixing components, the flow area of flue gas in the flue gas reheater is increased, the flow of flue gas is promoted, the load of the motor of the flue gas reheater is reduced, and the operation cost is saved.

[0015] 2. The heat exchange element is composed of alternately arranged first heat exchange fins and second heat exchange fins, and a plurality of straight-through ventilation gaps are left between the first heat exchange fins and the second heat exchange fins, the ventilation gaps have smooth wave shapes and large flow cross sections, the flow effect of flue gas is effectively increased, the flue gas reheater is prevented from being blocked, the pressure difference is effectively reduced, the purpose of energy saving and high efficiency is achieved, the flue gas of the heat exchange element is effectively blown away by the blowing air pipe arranged below the flue gas reheater, the cross leakage rate is reduced, and the blowing air pipe also has a certain cleaning effect on the heat exchange element.

[0016] 3. The flue gas reheater is equipped with a sealing fan and a low-leakage air inlet. The sealing fan can blow clean flue gas into the flue gas reheater through the low-leakage air inlet, thereby filling the cavity between the shell and the rotor with clean flue gas and forming a high-pressure environment. This causes the original flue gas and clean flue gas in the rotor to flow towards the center of the rotor, reducing the leakage of flue gas outward. In addition, the low-leakage air inlet is shaped like a horn tapering, which can enhance the blowing effect of clean flue gas, accelerate the filling of the cavity between the shell and the rotor with clean flue gas, save gas source, optimize the gas flow field and prevent dead zones that could cause some flue gas to leak out.

[0017] 4. A purge fan and purge duct are installed below the flue gas reheater. The purge duct has radially arranged strip-shaped air holes, so that the high-pressure gas discharged from the purge duct forms an air curtain from bottom to top, which directionally purges the heat exchange elements on the flue gas reheater. This prevents some of the original flue gas from being carried into the heat exchange elements in the original flue gas zone when the original flue gas zone and the clean flue gas zone of the flue gas reheater are exchanged. At the same time, the purge duct can also blow away the dust accumulated on the heat exchange elements to a certain extent, ensuring the heat exchange effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a flue gas reheater;

[0019] Figure 2 This is a schematic diagram of the structure of the present invention;

[0020] Figure 3 This is a top view of the structure of the present invention;

[0021] Figure 4 yes Figure 3 Schematic diagram of the low-leakage air inlet component in area A;

[0022] Figure 5 This is a schematic diagram of the structure of the support body of the present invention;

[0023] Figure 6 This is a schematic diagram of the heat exchange element of the present invention disassembled; Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] like Figure 1 As shown, the principle of the flue gas reheater is as follows: In actual production, the boiler will generate a large amount of untreated raw smoke. This raw smoke is first introduced into the flue gas reheater, where it is cooled by the heat exchange elements. Then, the raw smoke is guided to the absorption tower for desulfurization treatment. After desulfurization, the raw smoke becomes clean smoke. The clean smoke is heated by the flue gas reheater and then discharged. After further impurity removal treatment, the flue gas meets the emission standards and is discharged through the chimney.

[0026] like Figure 2 , Figure 3 As shown, an ultra-low leakage desulfurization rotary heat exchanger system includes: a flue gas reheater 1, a sealing purging system 2, and an air curtain purging system 3.

[0027] The flue gas reheater 1 includes a shell 11 and a rotor 12. The shell 11 is located around the rotor 12, and the shell 11 has a cavity 13 inside.

[0028] The sealing purging system 2 includes a sealing fan 21 and a low-leakage air inlet 22. The low-leakage air inlet 22 is located on the upper and lower sides of the flue gas reheater shell 11. The low-leakage air inlet 22 is electrically connected to the shell 11 and the cavity of the rotor 12. The sealing fan 21 introduces high-pressure gas into the cavity through the low-leakage air inlet 22 and forms a high-pressure environment, thereby causing the flue gas in the flue gas reheater to flow towards the center of the rotor, reducing the leakage of flue gas from the rotor into the cavity.

[0029] In order to improve the effectiveness of the sealing purging system, this invention has made certain improvements to the low-leakage air inlet component, specifically as follows: Figure 4 As shown, the low-leakage air inlet component 22 is composed of an inlet portion 221, a contraction portion 222, and an outlet portion 223 welded together in sequence. The low-leakage air inlet component 22 is generally shaped like a horn with a tapering shape. After the sealing fan 21 blows the clean flue gas into the inlet portion 221, the clean flue gas passes through the contraction portion 222 and is ejected from the outlet portion 223 with a smaller diameter. This increases the pressure of the clean flue gas when it is ejected, so that the ejected clean flue gas can fill the cavity between the rotor 11 and the housing 12 more quickly. At the same time, it can also prevent the clean flue gas from not reaching the end area of ​​the cavity after being blown into the cavity, which would cause the flue gas in the flue gas reheater to flow out from here and cause cross-leakage between the original flue gas and the clean flue gas.

[0030] The low-leakage air inlet component 22 has a trumpet-shaped structure that can adjust the direction of the high-pressure gas after it enters the cavity, so that the direction of the high-pressure gas after it enters the cavity is adjusted to be along the direction of the annular cavity. Compared with the traditional straight-through inlet, it can greatly accelerate the flow of high-pressure gas between the shells, thereby enhancing the sealing effect.

[0031] The air curtain purging system 3 includes a purging fan 31 and a purging duct 32. The purging duct 31 is fixed below the flue gas reheater 1. The purging duct 32 is provided with a plurality of strip-shaped air holes. The purging fan 31 is connected to the purging duct 32 in a conductive manner, thereby blowing high-pressure gas through the strip-shaped air holes toward the flue gas reheater 1 and forming an air curtain from bottom to top.

[0032] It should be noted that the high-pressure gas is clean flue gas directly drawn from the clean flue gas zone side of the flue gas reheater.

[0033] In order to ensure the flow of gas in the flue gas reheater 1, reduce the resistance of flue gas in the heat exchange element 123, and increase the purging efficiency of the purging duct 32, the present invention has made certain improvements to the heat exchange element 123 and the rotor.

[0034] Please combine Figure 3 , Figure 5 The rotor 12 of the flue gas reheater 1 includes: a plurality of circumferentially arranged support bodies 121, U-shaped members 122 and heat exchange elements 123. The support bodies 121 are divided into a plurality of grids by radial baffles and circumferential baffles. The U-shaped members 122 are located on the lower part of the inner side of the support bodies. The heat exchange elements 123 are supported and placed in the grids by the U-shaped members 122.

[0035] Support body:

[0036] like Figure 5 As shown, the support body 121 includes a radial baffle and a circumferential baffle, which divide the support body into several grids. The U-shaped member 122 is disposed on the lower part of the inner side of the support body. The heat exchange element 123 includes a first heat exchange plate 1231, a second heat exchange plate 1232, and an element support 1233. The first heat exchange plate 1231 and the second heat exchange plate 1232 are arranged alternately and fixed by the element support 1233 to form the heat exchange element 123.

[0037] U-shaped parts:

[0038] To ensure the structural strength of the U-shaped component 122 in supporting the heat exchange element 123, the U-shaped component 122 is made of Corten steel. The thickness of the U-shaped component 122 is 8~15mm, the length is 80~110mm, and the width is 40~50mm. At the same time, the U-shaped component 122 needs to be welded to the main body of the support through three welding processes. Thus, the U-shaped component 122 can not only support the heavy heat exchange element and meet the overall strength requirements, but also ensure that it will not be corroded in the high sulfur environment and meet the corrosion prevention requirements.

[0039] It should be noted that in this embodiment, the optimal values ​​of the U-shaped component 122 within the above parameter range are: thickness 10mm, length 105mm, and width 40mm. These parameters can satisfy the strength requirements of the U-shaped component 122 as a supporting structure, as well as the requirement that one U-shaped component 122 spans two adjacent grids. At the same time, they can minimize the cross-sectional area of ​​the U-shaped component 122 and reduce the flow resistance of the flue gas.

[0040] The support body 121 is divided into several grids by radial baffles and circumferential baffles. The U-shaped members 122 of the outermost and innermost grids are located on the inner side of the circumferential baffles, and the U-shaped members of the middle grids are located at the junction of the circumferential baffles and the radial baffles. Specifically, the U-shaped members should be able to span two grids, and the U-shaped members 122 are located at the four corners of the grid. With this arrangement, the heat exchange elements can be arranged as a whole in the grid and supported by the U-shaped members at the four corners.

[0041] By setting the U-shaped part 122 to support the heat exchange element 123, the area of ​​the support structure on the end face of the flue gas reheater can be reduced, which greatly reduces the resistance when the flue gas flows. At the same time, the U-shaped part 122 can also form an air duct, which is conducive to the flow of flue gas.

[0042] Heat exchange elements:

[0043] like Figure 6 As shown, the heat exchange element 123 includes a first heat exchange plate 1231, a second heat exchange plate 1232, and an element support 1233. The first heat exchange plate 1231 and the second heat exchange plate 1232 are arranged alternately, and a plurality of large-channel DC gaps are formed between the first heat exchange plate 1231 and the second heat exchange plate 1232.

[0044] The first heat exchange plate 1231 and the second heat exchange plate 1232 are made of enamel material. The first heat exchange plate 1231 is a plate with a corrugated cross section. The cross section of the second heat exchange plate 1232 is composed of several continuous cross-sectional segments, including S-shaped undulating curved segments and straight segments in the shape of a straight line. The curved segments of the first heat exchange plate 1231 and the corrugated cross section of the second heat exchange plate 1232 do not fit each other, thus forming several large-area flow gaps when the first heat exchange plate 1231 and the second heat exchange plate 1232 are stacked together.

[0045] Because the gap area between the first heat exchange plate 1231 and the second heat exchange plate 1232 is large and the gap is vertically continuous, this setting can ensure that the flue gas will not encounter excessive resistance when it flows, and can also reduce the phenomenon of flue gas particles adhering to the inside of the heat exchange element when the flue gas flows through the direct current gap. During cleaning, the gap of the direct current channel can also facilitate the rinsing of water and steam without reducing the kinetic energy of water and steam, thereby ensuring the cleaning effect.

[0046] In addition, the gap between the upper and lower DC channels is also beneficial to the purging of the air curtain purging system 3, effectively preventing some of the original flue gas from being carried in the heat exchange elements of the original flue gas zone when the original flue gas zone and the clean flue gas zone of the flue gas reheater 1 are exchanged, causing the problem of cross leakage of original and clean flue gas. At the same time, the DC gap can further reduce the adhesion of particles in the flue gas to the heat exchange elements under the purging of the purging air duct 32.

[0047] Of course, the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All modifications made according to the spirit and essence of the main technical solution of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A desulfurization rotary heat exchanger system with ultra-low leakage, characterized in that, include: Flue gas reheater (1), sealing purging system (2) and air curtain purging system (3); The flue gas reheater (1) includes a shell (11) and a rotor (12). The shell (11) is located around the rotor (12), and the shell (11) has a cavity (13). The rotor (12) includes several support bodies (121), U-shaped elements (122), and heat exchange elements (123). The support bodies (121) are divided into several grids by radial baffles and circumferential baffles. The U-shaped elements (122) are located at the lower part of the inner side of the support bodies (121). The heat exchange elements (123) are supported and placed in the grids by the U-shaped elements (122). The heat exchange element (123) includes a first heat exchange plate (1231), a second heat exchange plate (1232), and an element support (1233). The first heat exchange plate (1231) is an enamel plate with a corrugated cross section. The cross section of the second heat exchange plate (1232) is composed of several continuous cross-sectional segments, including a curved segment with an S-shaped undulation and a straight segment with a straight line shape. The first heat exchange plate (1231) and the second heat exchange plate (1232) are arranged alternately, thereby forming several large-channel DC gaps between the first heat exchange plate (1231) and the second heat exchange plate (1232). The sealing and purging system (2) includes a sealing fan (21) and a low-leakage air inlet (22). The low-leakage air inlet (22) is composed of an inlet (221), a constriction section (222), and an outlet (223) welded together in sequence. The low-leakage air inlet (22) is generally shaped like a horn with a tapering shape. The low-leakage air inlet (22) is connected to the cavity. The sealing fan (21) blows high-pressure gas into the cavity through the low-leakage air inlet (22) to form a high-pressure environment. The air curtain purging system (3) includes a purging fan (31) and a purging duct (32). The purging duct (32) is fixed below the flue gas reheater (1). The purging duct (32) is provided with a number of strip-shaped air holes. The purging fan (31) is connected to the purging duct (32) in a conductive manner, thereby blowing high-pressure gas through the strip-shaped air holes to the flue gas reheater (1) and forming an air curtain from bottom to top.

2. The ultra-low leakage desulfurization rotary heat exchanger system according to claim 1, characterized in that, The first heat exchange plate (1231) and the second heat exchange plate (1232) are arranged alternately and fixed by the element support (1233) to form the heat exchange element (123).

3. The novel ultra-low leakage desulfurization rotary heat exchanger device according to claim 1, characterized in that, The U-shaped part (122) is made of Corten steel, and the thickness of the U-shaped part (122) is 8~15mm, the length is 80~110mm, and the width is 40~50mm.

4. The novel ultra-low leakage desulfurization rotary heat exchanger device according to claim 1, characterized in that, The strip-shaped air hole on the purge duct (32) has a rectangular cross-section, and the width of the rectangle is 2cm to 7cm.

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