A low pressure vacuum condenser

Abstract

A low-pressure vacuum condenser mainly includes a shell and a heat transfer tube bundle installed in the shell, tube boxes installed at both ends of the shell, and a partition plate arranged longitudinally in the shell to divide the tube bundle shell into two shell structures, an upper shell and a lower shell. Through holes are opened at both ends of the partition plate to connect the upper shell with the lower shell; the tube bundle in the upper shell adopts square tube layout, and the tube bundle baffle adopts special-shaped baffle rod baffle; the tube bundle in the lower shell adopts regular triangle tube layout, and the tube bundle baffle adopts special-shaped baffle plate baffle. The different tube bundle heat exchange tube arrangements of the upper and lower shells of the present invention are combined with the tube bundle support method, which can not only reduce the fluid resistance drop in the shell of the heat exchanger and reduce the possibility of tube bundle vibration, but also take into account the heat transfer efficiency of the heat exchanger and improve the compactness of the equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of low-pressure vacuum space wall condensation heat transfer, and in particular relates to a low-pressure vacuum condenser. Background Art

[0002] At present, low-pressure vacuum space wall condensation heat transfer technology mostly adopts single shell structure or single external guide structure, shell split cooling technology. When using split condensation technology, the arrangement of the tube bundle heat exchange tubes is the same, and the tube bundle baffles are all baffles. When single shell condensation technology is used, there are disadvantages such as insufficient separation of non-condensable gas and condensate in the shell, low condensation efficiency, and more liquid in the non-condensable gas. When using the existing split condensation technology, there are also disadvantages such as large shell resistance drop and high vibration frequency of the tube bundle. Summary of the invention

[0003] The present invention provides a low-pressure vacuum condenser, which takes into account the condensation resistance and heat transfer efficiency of shell-side fluid and reduces the vibration frequency of the tube bundle to a very low level.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A low-pressure vacuum condenser mainly comprises a shell and a heat transfer tube bundle installed in the shell, tube boxes installed at both ends of the shell, a partition plate longitudinally arranged in the shell divides the tube bundle shell into an upper shell and a lower shell, through holes are opened at both ends of the partition plate to connect the upper shell with the lower shell; the tube bundle in the upper shell adopts square tube layout, and the tube bundle baffle adopts special-shaped baffle rod baffle; the tube bundle in the lower shell adopts regular triangle tube layout, and the tube bundle baffle adopts special-shaped baffle plate baffle.

[0006] A coaxial middle outer flow guide cylinder is provided in the middle of the shell, and a shell-side fluid inlet is provided on the upper part of the shell; a coaxial middle inner distribution cylinder is provided inside the middle outer flow guide cylinder, and the middle outer flow guide cylinder is connected with the upper shell side through the middle inner distribution cylinder; the middle outer flow guide cylinder and the middle inner distribution cylinder are divided into two independent parts by a longitudinal partition.

[0007] The special-shaped baffle rods are of a circular segment structure, and the circular baffle rods are evenly distributed longitudinally or transversely on the circular segment-shaped support ring and the two are arranged at intervals.

[0008] The special-shaped baffle is a circular segment structure, the lower part of the baffle is not provided with a tube area, and a guide hole is provided in the heat exchange tube bridge area of ​​the tube area.

[0009] The present invention is arranged horizontally, and the shell side adopts an upper and lower shell side structure, wherein the tube bundle in the upper shell side adopts square tube layout, and the baffle mode of the tube bundle in the upper shell side adopts special-shaped baffle rod baffle; the tube bundle in the lower shell side adopts triangular tube layout, and the baffle mode of the tube bundle in the lower shell side adopts special-shaped baffle plate baffle. The combination of different tube bundle heat exchange tube layouts and tube bundle support methods in the upper and lower shell sides can not only reduce the fluid resistance drop in the shell side of the heat exchanger and reduce the possibility of tube bundle vibration, but also take into account the heat transfer efficiency of the heat exchanger and improve the compactness of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention;

[0011] Figure 2 It is a schematic cross-sectional diagram of the shell side of the present invention;

[0012] Figure 3 It is a schematic cross-sectional view of the middle guide tube of the present invention;

[0013] Figure 4 It is a schematic diagram of a special-shaped baffle rod structure of the present invention;

[0014] Figure 5 It is a schematic diagram of another special-shaped baffle rod structure of the present invention;

[0015] Figure 6 It is a schematic diagram of a special-shaped baffle of the present invention;

[0016] Figure numbers: front tube box 1; shell 2; middle inner distribution tube 3; rear tube box 4; support 5; tube side exhaust port 6; special-shaped baffle rod 7; shell side fluid inlet 8; middle outer guide tube 9; heat transfer tube bundle 10; tube side fluid outlet 11; tube side drain port 12; special-shaped baffle 13; shell side condensate outlet 14; tube side fluid outlet 15; longitudinal partition 16; partition 17; shell side non-condensable gas outlet 18; heat exchange tube 19; circular support ring 20; baffle rod 21; guide hole 22; heat exchange tube hole 23. DETAILED DESCRIPTION

[0017] The present invention and its beneficial effects are further described below in conjunction with the accompanying drawings.

[0018] like Figure 1 As shown, a low-pressure vacuum condenser includes a front tube box 1, a shell 2, a rear tube box 4, a heat transfer tube bundle 10 and a support 5. The front tube box 1 and the rear tube box 4 are sealed and connected to the tube sheets at both ends of the heat transfer tube bundle 10, and the shell 2 is sealed and connected to the tube sheets at both ends of the heat transfer tube bundle 10 and wraps the heat transfer tube bundle 10 inside the shell 2; the support 5 supports the entire condenser, and the condenser is arranged horizontally. In the present invention, a cold fluid flows inside the heat transfer tube bundle, and a hot fluid flows outside the heat transfer tube bundle. The hot fluid and the cold fluid transfer heat through the inter-wall. After heat exchange, the hot fluid is condensed into liquid and a small amount of non-condensable gas is separated.

[0019] like Figure 2 As shown, the tube-side fluid flows into the front tube box 1 from the tube-side fluid inlet 15, enters the tube bundle 10 from the front tube box 1, exchanges heat with the shell-side fluid partition wall, and then flows into the rear tube box 4, and flows out from the tube-side fluid outlet 11. The front tube box 1 is provided with a tube-side exhaust port 6, and the rear tube box 4 is provided with a tube-side liquid discharge port 12.

[0020] like Figure 3 As shown, the partition plate 17 longitudinally arranged in the shell 2 divides the tube bundle shell into an upper shell and a lower shell. Through holes are opened at both ends of the partition plate 17 to connect the upper shell and the lower shell. The tube bundle in the upper shell adopts a square tube layout, and the tube bundle baffle adopts a special-shaped baffle rod baffle; the tube bundle in the lower shell adopts a regular triangle tube layout, and the tube bundle baffle adopts a special-shaped baffle plate baffle.

[0021] The shell side of the present invention adopts a two-shell side structure of an upper shell side and a lower shell side, so that the upper shell tube bundle is used to condense most of the shell side low-pressure vacuum fluid, so most of the fluid resistance is also concentrated here, and the vibration of the tube bundle is also more intense. The use of baffle rods in this area can effectively reduce fluid resistance and greatly reduce the possibility of tube bundle vibration. The square tube layout of the upper shell side tube bundle can meet the conditions for using baffle rods for baffles, and the square tube layout also reduces the fluid flow rate in this area, thereby reducing the fluid flow rate and the vibration frequency of the tube bundle.

[0022] The lower shell tube bundle is used for secondary condensation of a small portion of uncondensed shell-side fluid. The fluid velocity in this area is low and the fluid resistance is small, so the heat transfer area should be increased with the smallest possible space. The lower shell-side tube bundle adopts regular triangle pipe layout, which makes the best use of the lower shell-side space to increase the heat exchange area. The lower shell-side tube bundle adopts special-shaped baffle baffles, which are arranged with large spacing, reducing the difficulty of condenser manufacturing while taking into account pressure drop, heat transfer and vibration.

[0023] The upper shell tube bundle and the lower shell tube bundle adopt two different pipe layout methods and baffle support methods, which fully consider the characteristics of low-pressure vacuum gas condensation in the shell side, that is, meet its demanding resistance drop requirements, and fully consider the heat transfer efficiency of the condenser, while reducing the vibration frequency of the tube bundle to a very low level.

[0024] like Figure 1 , Figure 2 , Figure 3As shown, the shell 2 is provided with a coaxial middle outer flow guide tube 9 in the middle, and a shell-side fluid inlet 8 is provided on the upper part thereof; a coaxial middle inner distribution tube 3 is provided inside the middle outer flow guide tube 9, which is connected to the shell and can also be a part of the shell, for preventing the shell-side fluid from being impacted, guiding the fluid, and evenly distributing the fluid. The middle outer flow guide tube 9 is connected to the upper shell side through the middle inner distribution tube 3; the middle outer flow guide tube 9 and the middle inner distribution tube 3 are divided into two independent parts by a longitudinal partition 16, and the longitudinal partition is located at the shell-side separation to isolate the shell-side inlet fluid and the condensed condensate and non-condensable gas.

[0025] like Figure 3 As shown, in order to ensure the process performance of the condenser, a shell-side condensate outlet 14 is provided at the lower part of the middle outer draft tube 9; a shell-side non-condensable gas outlet 18 is provided on the middle outer draft tube 9 at the lower part of the longitudinal partition 14.

[0026] like Figure 4 , Figure 5 As shown, the special-shaped baffle rods are of a circular segment structure, and the baffle round rods 21 are evenly distributed on the circular segment support ring 21 and the two are arranged at intervals. The circular segment support ring 21 corresponds to the cross-sectional shape of the upper shell side, and the baffle round rods arranged at intervals in the longitudinal or transverse direction form a group of four rods to clamp and support the heat exchange tube bundle and form baffles.

[0027] The special-shaped baffle is a circular segment structure, with a gap in the lower area of ​​the baffle where no pipes are laid, and a guide hole 22 is opened in the heat exchange pipe bridge area in the pipe laying area. The lower edge of the special-shaped baffle corresponds to the cross-sectional shape of the shell side. The gap in the lower area where no pipes are laid diverts the condensed liquid phase flow out of the shell side, and the guide hole in the heat exchange pipe bridge area in the pipe laying area has both the function of baffle enhancement and heat transfer, and the function of guide. At the same time, this type of baffle fully supports the lower shell side heat exchange pipe, greatly reducing the vibration of the lower shell side heat exchange pipe.

[0028] In order to improve the heat transfer performance of the condenser, the heat exchange tubes 19 of the heat transfer tube bundle 10 are threaded tubes or corrugated tubes.

[0029] like Figure 1 , Figure 2As shown, an outer guide tube 9 is arranged in the middle of the shell 2, and an inner distribution tube 3 is arranged inside the outer guide tube 9. The shell-side fluid first enters the outer guide tube 9 through the shell-side fluid inlet 8, and the shell-side fluid first flows to the inner distribution tube 3. After being blocked and anti-impacted, it diffuses and slows down in the outer guide tube 9. The end of the inner distribution tube 3 of the shell-side fluid is not perforated. After being evenly distributed through the distribution holes of the inner distribution tube 3, the shell-side fluid enters the tube bundle 20, and heat-exchanges with the wall between the tube-side fluid in the tube bundle 20 to condense. Most of the fluid is condensed in the first shell side. After condensation, the fluid flows into the second shell side through the holes at both ends of the longitudinal partition 17 of the shell side of the tube bundle, and heat-exchanges with the wall between the tube-side fluid in the second shell side and condenses again. The condensed non-condensable gas and condensate enter the outer guide tube 9 in the middle of the shell again, and the non-condensable gas flows out of the equipment through the shell-side non-condensable gas outlet 18, and the condensate flows out of the equipment through the shell-side condensate outlet 14. The two shell-side fluids are separated by the outer guide tube longitudinal partition 16 in the outer guide tube 9.

[0030] The upper and lower shells of the condenser adopt different pipe layout methods and different baffle support methods, taking into account the pressure drop and heat transfer of the low-pressure vacuum fluid in the shell, ensuring the full separation of non-condensable gas and condensate, and at the same time reducing the vibration frequency of the tube bundle as much as possible, thereby improving the heat transfer efficiency of the heat exchanger and reducing the equipment cost and floor space.

Claims

1. A low-pressure vacuum condenser, mainly comprising a shell and a heat transfer tube bundle installed in the shell, and a tube box installed at both ends of the shell, characterized in that: A partition plate (17) longitudinally arranged in the shell (2) divides the tube bundle shell side into two shell side structures, an upper shell side and a lower shell side. Through holes are opened at both ends of the partition plate (17) to connect the upper shell side with the lower shell side. The tube bundle in the upper shell side adopts a square tube layout, and the tube bundle baffle adopts a special-shaped baffle rod baffle; the tube bundle in the lower shell side adopts an equilateral triangle tube layout, and the tube bundle baffle adopts a special-shaped baffle plate baffle.

2. A low-pressure vacuum condenser according to claim 1, characterized in that: The shell (2) is provided with a coaxial middle outer flow guide tube (9) in the middle part, and a shell-side fluid inlet (8) is provided at the upper part of the shell (2); a coaxial middle inner distribution tube (3) is provided inside the middle outer flow guide tube (9), and the middle outer flow guide tube (9) is connected to the upper shell side through the middle inner distribution tube (3); the middle outer flow guide tube (9) and the middle inner distribution tube (3) are divided into two independent parts by a longitudinal partition plate (16).

3. A low-pressure vacuum condenser as claimed in claim 2, characterized in that: A shell-side condensate outlet (14) is provided at the lower portion of the middle outer draft tube (9); and a shell-side non-condensable gas outlet (18) is provided on the middle outer draft tube (9) below the longitudinal partition plate (16).

4. A low-pressure vacuum condenser according to claim 1, characterized in that: The special-shaped baffle rods are of a circular segment structure, and the circular baffle rods are evenly distributed longitudinally or transversely on the circular segment-shaped support ring (21) and the two are arranged at intervals.

5. A low-pressure vacuum condenser according to claim 1, characterized in that: The special-shaped baffle is a circular segment-shaped structure, the lower part of the baffle is not provided with a tube-free area, and a guide hole (22) is provided in the heat exchange tube bridge area of ​​the tube-providing area.

6. A low-pressure vacuum condenser according to any one of claims 1 to 5, characterized in that: The heat exchange tubes (19) of the heat transfer tube bundle (10) are threaded tubes or corrugated tubes.

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