A lateral steam inlet condenser tube bundle

Abstract

The present invention provides a lateral steam inlet condenser tube bundle, which comprises a plurality of heat exchange tubes. The plurality of heat exchange tubes form a front tube bundle area, a rear tube bundle area and an air-cooled tube bundle area. The front tube bundle area, the rear tube bundle area and the air-cooled tube bundle area are sequentially arranged in the inner cavity of the condenser along the exhaust direction of the condenser, and the air-cooled tube bundle area is provided with an air extraction port. The front tube bundle area is provided with a front intermediate steam channel along the exhaust direction of the condenser, and the rear tube bundle area is provided with a rear intermediate steam channel along the exhaust direction of the condenser. The front intermediate steam channel and the rear intermediate steam channel are communicated with each other, and the air-cooled tube bundle area is located at the tail end of the rear intermediate steam channel. The structure of the present invention is compact, which can save the investment of the power plant while making the steam flow field in the tube bundle uniform without eddy current, having a small shell-side steam resistance, a uniform heat load distribution, a high steam condensation rate, and relatively high heat transfer coefficient and operating vacuum degree of the condenser.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchangers, and in particular to a side steam inlet condenser tube bundle. Background Art

[0002] The side-inlet condenser is a shell-and-tube heat exchanger and an important component of a gas-steam combined cycle unit. Its function is to condense the exhaust steam discharged from the low-pressure cylinder of the steam turbine into water and establish and maintain a certain vacuum value at the exhaust port of the steam turbine. The rationality of the arrangement of the condenser cooling tube bundle has an important influence on the steam condensation process, and has a great impact on its heat exchange performance and the energy consumption of the unit. Unreasonable arrangement of the tube bundle will cause unreasonable steam flow field, resulting in uneven heat load distribution, local air accumulation, excessive flow resistance, large supercooling, air leakage (uncondensed steam directly enters the air cooling area), etc.

[0003] Therefore, reasonable tube bundle arrangement is the basis for ensuring the performance of the side-inlet condenser. Studies have shown that the actual condenser vacuum degree of unreasonable side-inlet condenser tube bundle arrangement may differ from the vacuum degree calculated according to the HEI standard by more than 1KPa, which directly and significantly affects the output and economy of the unit. With a reasonable condenser tube bundle arrangement, the energy-saving benefits of the unit are obvious.

[0004] There are few existing pipe layout methods for side-inlet condensers in China, and there are more or less problems such as excessive shell side flow resistance and large subcooling, and the actual heat transfer coefficient is not ideal. Most of the existing pipe layout methods for lower exhaust condensers are not compact enough. If they are directly inverted for side-inlet condensers, the investment in side-inlet condensers will increase significantly. Summary of the invention

[0005] The object of the present invention is to provide a side steam inlet condenser tube bundle, which has a simple and compact structure, a straight tube bundle steam flow field, few deflections, a uniform flow field without vortex, a small shell side steam resistance, a high condenser condensation rate and a low cost.

[0006] An embodiment of the present invention is achieved through the following technical scheme: a side steam inlet condenser tube bundle, including a plurality of heat exchange tubes, the plurality of heat exchange tubes form a front end tube bundle area, a rear end tube bundle area and an air cooling tube bundle area, the front end tube bundle area, the rear end tube bundle area and the air cooling tube bundle area are sequentially arranged in the condenser cavity along the exhaust direction of the condenser, and the air cooling tube bundle area is provided with an air extraction port.

[0007] Furthermore, the front tube bundle area is provided with a front intermediate steam duct along the exhaust direction of the condenser, and the rear tube bundle area is provided with a rear intermediate steam duct along the exhaust direction of the condenser. The front intermediate steam duct and the rear intermediate steam duct are connected, and the air-cooling tube bundle area is located at the tail end of the rear intermediate steam duct.

[0008] Further, the front tube bundle area includes a pair of V-shaped tube bundle areas, the front intermediate steam passage is arranged in the V-shaped tube bundle area, the tip of the V-shaped tube bundle area faces the exhaust side of the condenser, let the axis of the tube bundle be x, this pair of V-shaped tube bundle areas are symmetrically arranged up and down with the axis x as the midline, and the adjacent side edges of this pair of V-shaped tube bundle areas are connected, and the end of the V-shaped tube bundle area far from the condenser exhaust is connected to the rear tube bundle area.

[0009] Further, the rear tube bundle area includes a pair of wing tube bundle areas, this pair of wing tube bundle areas are symmetrically arranged up and down with the axis x as the midline, a rear intermediate steam passage is formed between this pair of wing tube bundle areas, this pair of wing tube bundle areas are respectively connected to the adjacent V-shaped tube bundle areas, and the air-cooled tube bundle area is embedded at the end of this pair of wing tube bundle areas.

[0010] Further, a first air-cooling baffle is vertically arranged on the side of the air-cooled tube bundle area far from the front tube bundle area, a second air-cooling baffle is arranged at the upper end of the first air-cooling baffle, a third air-cooling baffle is arranged at the lower end of the first air-cooling baffle, there is an included angle α between the extension line of the second air-cooling baffle and the axis x, there is an included angle β between the extension line of the third air-cooling baffle and the axis x, the first air-cooling baffle, the second air-cooling baffle and the third air-cooling baffle make the air-cooled tube bundle area form a gradually shrinking area, and the tube bundle on the air-cooled tube bundle area and the air-cooled tube bundle area form a gradually shrinking air-cooled tube bundle area.

[0011] Further, the included angle α is equal to the included angle β, and its range is 25° - 65°.

[0012] Further, several air intake notches are arranged in the wing tube bundle area.

[0013] Further, the percentage of the tube bundle in the air-cooled tube bundle area in the total number of the whole tube bundle is 5% - 7%.

[0014] Further, the tube layout method of the tube bundle is a single-pass of cooling water.

[0015] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0016] 1. The steam flow field of the tube bundle is straight, with less flow deflection, the flow field is uniform without eddy current, the steam resistance on the shell side is small, the heat load distribution is uniform, the heat transfer coefficient and the operating vacuum degree of the condenser are both relatively high, the heat transfer coefficient can be increased by more than 15% compared with the ordinary tube layout scheme, and is 10% - 20% higher than the calculated value according to HEI. Its steam resistance on the shell side is 40% - 60% of that of the ordinary tube bundle (when there is no air leakage), and the energy-saving effect of the unit is obvious.

[0017] 2. The tube bundle structure is simple and compact, which is convenient for the tube layout and installation of large-scale side-inlet condensers, and reduces the production and manufacturing cost. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 It is a structural schematic diagram of the front tube bundle area in the present invention;

[0021] Figure 3 It is a structural schematic diagram of the rear tube bundle area in the present invention;

[0022] Figure 4 It is a structural schematic diagram of the air-cooled tube bundle area in the present invention;

[0023] Figure 5 It is an overall state diagram of the present invention;

[0024] Icon: 1 - front tube bundle area, 11 - V-shaped tube bundle area, 12 - front intermediate steam channel, 2 - rear tube bundle area, 21 - flank tube bundle area, 22 - rear intermediate steam channel, 23 - air intake notch, 3 - air-cooled tube bundle area, 31 - rectangular tube bundle area, 32 - tapered air-cooled tube bundle area, 41 - first air-cooled baffle, 42 - second air-cooled baffle, 43 - third air-cooled baffle. Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0027] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0028] In the description of the present invention, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this application is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0029] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, if terms such as "set", "installed", "connected", "linked" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] Embodiment 1

[0031] Please refer to Figures 1 to 4 , this embodiment provides a laterally inlet steam condenser tube bundle. The laterally inlet steam condenser uses lateral inlet, and the exhaust steam discharged from the low-pressure cylinder of the steam turbine flows horizontally in the inner cavity of the condenser. This embodiment includes a number of heat exchange tubes, and a number of heat exchange tubes are arranged to form a front tube bundle area 1, a rear tube bundle area 2, and an air-cooled tube bundle area 3. This arrangement forms a specific shape through the heat exchange tubes on the periphery of the front tube bundle area 1, the rear tube bundle area 2, and the air-cooled tube bundle area 3. As Figure 5 shown, the front tube bundle area 1, the rear tube bundle area 2, and the air-cooled tube bundle area 3 are sequentially arranged in the inner cavity of the condenser along the exhaust direction of the condenser. Specifically, the percentage of the tube bundle in the air-cooled tube bundle area 3 in the total number of the whole tube bundle is 5%-7%; the air-cooled tube bundle area 3 is configured with an air extraction port, and the air extraction port is used to connect to an air extraction system through pipe fittings. The evacuation system is used to suck away the steam and non-condensable gases that have not been fully cooled and condensed, facilitating the subsequent introduction of steam, so that the condenser maintains a certain vacuum degree, avoiding excessive pressure in the inner cavity of the condenser and resulting in unsmooth exhaust and a decrease in the unit efficiency. By arranging the front tube bundle area 1, the rear tube bundle area 2, and the air-cooled tube bundle area 3 sequentially along the exhaust direction of the condenser, after the exhaust gas enters the inner cavity of the condenser, it is sequentially condensed through the front tube bundle area 1 and the rear tube bundle area 2. Therefore, the steam flow field in the condenser is straight, with few bends, the streamline is uniform, there is no vortex in the steam flow, the steam has been fully condensed before entering the air-cooled tube bundle area at the tail end, and finally it is sucked away through the air extraction port of the air-cooled tube bundle area 3 at the tail end, and the overall heat transfer coefficient of the condenser is high.

[0032] The front tube bundle area 1 is provided with a front intermediate steam channel 12 along the exhaust direction of the condenser, and the rear tube bundle area 2 is provided with a rear intermediate steam channel 22 along the exhaust direction of the condenser. The front intermediate steam channel 12 and the rear intermediate steam channel 22 are connected. The air-cooled tube bundle area 3 is located at the end of the rear intermediate steam channel 22. By configuring the front intermediate steam channel 12 and the rear intermediate steam channel 22, the fluidity of the steam in the front tube bundle area 1 and the rear tube bundle area 2 is increased. And by arranging both the front intermediate steam channel 12 and the rear intermediate steam channel 22 along the exhaust direction, the characteristics of straight steam streamline and few bends are also ensured inside the tube bundle, so that there is no eddy in the steam flow. The structure is simple but ensures a high heat transfer coefficient.

[0033] In this embodiment, further, the front tube bundle area 1 includes a pair of V-shaped tube bundle areas 11. The front intermediate steam channel 12 is arranged in the V-shaped tube bundle areas 11. The tip of the V-shaped tube bundle areas 11 faces the exhaust side of the condenser. Let the axis of the tube bundle be x. This pair of V-shaped tube bundle areas 11 are symmetrically arranged up and down with the axis x as the center line, and the adjacent sides of this pair of V-shaped tube bundle areas 11 are connected. The end of the V-shaped tube bundle areas 11 far from the exhaust of the condenser is connected to the rear tube bundle area 2. By configuring the front tube bundle area 1 as a pair of V-shaped tube bundle areas 11, the exhaust of the condenser first contacts the tip of the V-shaped tube bundle areas 11, reducing the resistance generated between the front tube bundle area 1 and the steam while increasing the heat transfer area, improving the overall heat transfer efficiency of the condenser, and making the steam streamline in the condenser uniform.

[0034] In the present invention, further, the rear tube bundle area 2 includes a pair of flank tube bundle areas 21. This pair of flank tube bundle areas 21 are symmetrically arranged up and down with the axis x as the center line. A rear intermediate steam channel 22 is formed between this pair of flank tube bundle areas 21. This pair of flank tube bundle areas 21 are respectively connected to the adjacent V-shaped tube bundle areas 11. The air-cooled tube bundle area 3 is embedded between this pair of flank tube bundle areas 21. Specifically, the air-cooled tube bundle area 3 is located at the end of the flank tube bundle areas 21. This pair of flank tube bundle areas 21 are in a clamping shape and are located on both sides of the air-cooled tube bundle area 3. By configuring the rear tube bundle area 2 as a pair of flank tube bundle areas 21, its structure is simple and compact, facilitating pipe laying while ensuring a high heat transfer coefficient. The flank tube bundle areas 21 are provided with several air intake notches. By configuring the air intake notches, the air intake area of the flank tube bundle areas 21 is increased, making the steam enter the tube bundle of the flank tube bundle areas 21 smoothly and improving the heat transfer efficiency.

[0035] Furthermore, in the present invention, a first air-cooled baffle 41 is vertically disposed on the side of the air-cooled tube bundle area 3 away from the front tube bundle area 1. A second air-cooled baffle 42 is disposed at the upper end of the first air-cooled baffle 41, and a third air-cooled baffle 43 is disposed at the lower end of the first air-cooled baffle 41. An included angle α exists between the extension line of the second air-cooled baffle 42 and the axis x, and an included angle β exists between the extension line of the third air-cooled baffle 43 and the axis x. The included angle α is equal to the included angle β, and the range thereof is 25°-65°. The first air-cooled baffle 41, the second air-cooled baffle 42, and the third air-cooled baffle 43 make the air-cooled tube bundle area 3 form a gradually shrinking area. The air-cooled tube bundle area 3 and the tube bundles on the air-cooled tube bundle area 3 form a gradually shrinking air-cooled tube bundle area 32. The gradually shrinking air-cooled tube bundle area 32 is in an inverted trapezoid shape. Thus, the air-cooled tube bundle area 3 includes a connected rectangular tube bundle area 31 and an inverted trapezoid-shaped gradually shrinking air-cooled tube bundle area 32. The upper and lower two flank tube bundle areas 21 surround the rectangular tube bundle area 31. The gradually shrinking air-cooled tube bundle area 32 is embedded at the end of the flank tube bundle area 21, showing a semi-surrounding shape. The axes of the rectangular tube bundle area 31 and the gradually shrinking air-cooled tube bundle area 32 are both located on the axis x and at the end of the rear intermediate steam passage 22, ensuring a straight steam flow field, less flow deflection, uniform streamlines, small steam resistance, and uniform heat load. In the lateral steam inlet condenser tube layout method, there is no mixing area between the uncondensed gas and the steam, and there is no eddy in the steam flow, making the overall heat transfer coefficient of the condenser high, and having a relatively high operating vacuum degree. The heat transfer coefficient can be increased by more than 15% compared with the ordinary tube layout scheme, and is 10%-20% higher than the calculated value according to HEI. The shell-side steam resistance is 40%-60% of that of the ordinary tube bundle (when there is no air leakage). The energy-saving effect of the unit is obvious. Moreover, the overall structure is simple and compact, facilitating tube layout and production, and greatly reducing the production and manufacturing cost.

[0036] Further in this embodiment, the tube layout method of the tube bundle is a single-pass cooling water.

[0037] When steam enters the inner cavity of the condenser from the exhaust port on the side of the condenser, the steam sequentially passes through the front tube bundle area 1 and the rear tube bundle area 2. In the front tube bundle area 1, after the steam contacts the tip of the V-shaped tube bundle area 11, it enters the V-shaped tube bundle area 11 along its streamline for preliminary cooling and condensation, reducing the resistance generated between the front tube bundle area 1 and the steam while increasing the heat transfer area. The steam flow path is straight, uniform, and fast. Then the steam is carried into the rear tube bundle area 2 through the front intermediate steam passage 12. The steam is fully condensed after passing through the rear tube bundle area 2. Finally, the uncondensed gas enters the air-cooled tube bundle area 3 from the end and is drawn away from the air extraction port. Since the steam outside and inside the tube bundle is in the same flow direction, the steam flow field is straight, there is less flow deflection, the streamlines are uniform, the steam resistance is small, and the heat load is uniform. There is no eddy in the steam flow, making the overall heat transfer coefficient of the condenser high.

[0038] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lateral steam inlet condenser tube bundle, characterized in that: It includes a number of heat exchange tubes, and the number of heat exchange tubes form a front tube bundle area, a rear tube bundle area and an air-cooled tube bundle area. The front tube bundle area, the rear tube bundle area and the air-cooled tube bundle area are sequentially arranged in the inner cavity of the condenser along the exhaust direction of the condenser, and an air extraction port is arranged in the air-cooled tube bundle area; A first air-cooled baffle is vertically arranged on one side of the air-cooled tube bundle area away from the front tube bundle area. A second air-cooled baffle is arranged at the upper end of the first air-cooled baffle, and a third air-cooled baffle is arranged at the lower end of the first air-cooled baffle. An included angle α exists between the extension line of the second air-cooled baffle and the axis x, and an included angle β exists between the extension line of the third air-cooled baffle and the axis x. The first air-cooled baffle, the second air-cooled baffle and the third air-cooled baffle make the air-cooled tube bundle area form a gradually shrinking area, and the air-cooled tube bundle area and the tube bundle on the air-cooled tube bundle area form a gradually shrinking air-cooled tube bundle area; The included angle α is equal to the included angle β and is 25°-65°; The air-cooled tube bundle area includes a connected rectangular tube bundle area and a gradually shrinking air-cooled tube bundle area in an inverted trapezoidal shape; The rear tube bundle area includes a pair of flank tube bundle areas, and the pair of flank tube bundle areas are symmetrically arranged up and down with the axis x as the midline. A rear middle steam passage is formed between the pair of flank tube bundle areas. The pair of flank tube bundle areas are respectively connected to the adjacent V-shaped tube bundle areas, and the air-cooled tube bundle area is embedded at the end of the pair of flank tube bundle areas in a semi-surrounding shape.

2. The lateral steam inlet condenser tube bundle according to claim 1, characterized in that, A front middle steam passage is arranged in the front tube bundle area along the exhaust direction of the condenser, and a rear middle steam passage is arranged in the rear tube bundle area along the exhaust direction of the condenser. The front middle steam passage and the rear middle steam passage are connected, and the air-cooled tube bundle area is located at the end of the rear middle steam passage.

3. The lateral steam inlet condenser tube bundle according to claim 2, characterized in that, The front tube bundle area includes a pair of V-shaped tube bundle areas, and the front middle steam passage is arranged in the V-shaped tube bundle area. The tip of the V-shaped tube bundle area faces the exhaust side of the condenser. Let the tube bundle central axis be x. The pair of V-shaped tube bundle areas are symmetrically arranged up and down with the axis x as the midline, and the adjacent sides of the pair of V-shaped tube bundle areas are connected. The end of the V-shaped tube bundle area away from the exhaust of the condenser is connected to the rear tube bundle area.

4. The lateral steam inlet condenser tube bundle according to claim 3, wherein, The flank tube bundle area is provided with several air intake notches.

5. The lateral steam inlet condenser tube bundle according to claim 2, characterized in that, The percentage of the tube bundle in the air-cooled tube bundle area in the total number of the whole tube bundle is 5%-7%.

6. A lateral steam inlet condenser tube bundle according to claim 2, characterized in that, The tube layout method is a single-pass of cooling water.

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