A vertical double-section fixed tube sheet steam-water heat exchanger

Abstract

This utility model discloses a vertical double-section fixed tube sheet steam-water heat exchanger, relating to the technical field of heat exchangers. It includes an upper steam-water heat exchanger and a lower steam-water heat exchanger. The heat exchange tube bundles of the two heat exchangers are connected in the middle by a tube box, and the shell tubes of the two heat exchangers are connected by a steam connecting pipe. The upper end of the upper steam-water heat exchanger has a raw water outlet, and the upper shell has a steam inlet. The lower end of the lower steam-water heat exchanger has a raw water inlet, and the lower shell has a condensate outlet. This utility model's vertical double-section fixed tube sheet steam-water heat exchanger adopts a two-section connection, connecting the upper and lower heat exchangers and used to transport a mixture of steam and condensate. From a maintenance perspective, this allows for quick disassembly and installation of the heat exchanger, reducing the difficulty of cleaning tube bundle blockages. The heat exchanger's external dimensions are rationally designed while ensuring sufficient heat exchange area.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchangers, in particular to a vertical double-section fixed tube sheet steam-water heat exchanger. Background Art

[0002] A heat exchanger is an energy-saving device that realizes heat transfer between two or more fluids at different temperatures. It transfers heat from a fluid with a higher temperature to a fluid with a lower temperature so that the fluid temperature reaches the specified index of the process to meet the needs of process conditions. It is also one of the main equipment for improving energy utilization. It is an efficient steam-water heat exchange equipment widely used in various heating systems and hot water systems.

[0003] The vertical double-section fixed tube sheet steam-water heat exchanger is composed of tube sheets, separate shells, double-section tube bundles and other components. The overall structure is compact and relatively simple to manufacture. The design principle of the heat exchanger is based on heat transfer through the heat exchanger, allowing the fluid passing through liquids of different temperatures to flow in the tube bundle and achieve heat exchange with the steam in the tube shell. However, in the actual production application process, the fixed tube sheet heat exchanger will encounter some problems. Due to the influence of scouring of the heat exchanger tube bundle and the sediment and corrosiveness of the raw water quality, the tube bundle will often be blocked after the heat exchanger has been running for about three months, resulting in a decrease in the outlet water temperature and water volume, which in turn reduces the heat exchange efficiency, and even causes leakage and blockage in the tube bundle, resulting in the mixing of water and steam. The mixed condensed water cannot be recovered, and the outlet water temperature and water volume of the heat exchanger unit decrease, which has a great impact on the production process. Because the tube bundle is inside the heat exchanger, the structure is a side-by-side enclosure with a length of about 4 meters, cleaning and welding are very difficult. In addition, the cleaning of scale or maintenance process requires the cooperation of multiple people, which takes a lot of time and causes human resources, material resources and financial consumption to the enterprise. Utility Model Content

[0004] The utility model aims to provide a vertical double-section fixed tube sheet steam-water heat exchanger to solve the problems existing in the prior art, so that the tube bundle can be quickly disassembled and assembled, and the difficulty of cleaning and repairing the tube bundle is reduced.

[0005] To achieve the above purpose, the utility model provides the following solutions:

[0006] The utility model provides a vertical double-section fixed tube sheet steam-water heat exchanger, comprising an upper steam-water heat exchanger and a lower steam-water heat exchanger, wherein the middle parts of the upper steam-water heat exchanger and the lower steam-water heat exchanger are connected through a pipe box to connect the heat exchange tube bundles of the two steam-water heat exchangers, and the shell pipes of the two steam-water heat exchangers are connected through a steam connecting pipe, a raw water outlet is arranged on the upper head of the upper steam-water heat exchanger, and a steam inlet is arranged on the upper shell, and a raw water inlet is arranged on the lower head of the lower steam-water heat exchanger, and a condensed water outlet is arranged on the lower shell.

[0007] Preferably, the upper head and the upper shell, as well as the lower head and the lower shell are connected via head flanges, and all pressure-bearing connecting welds adopt a full-penetration structure, and the upper head and the lower head are both made of stainless steel.

[0008] Preferably, tube sheets are sealed and welded at both ends of the upper shell and the lower shell, and the tube sheets are made of stainless steel composite plates with a thickness of 3 mm.

[0009] Preferably, a plurality of heat exchange tubes are evenly distributed in the heat exchange tube bundle, the ends of the heat exchange tubes all pass through the tube sheet and are welded to the tube sheet by tungsten inert gas arc welding, and the heat exchange tubes are stainless steel straight tubes.

[0010] Preferably, baffles are provided in the shells of the upper steam-water heat exchanger and the lower steam-water heat exchanger, and a support seat is provided on the lower shell.

[0011] Preferably, a bumper plate is provided inside the steam inlet.

[0012] Preferably, the pipe box is a cavity formed by sealingly connecting two head flanges, and both ends of the cavity are connected to the heat exchange tube bundle.

[0013] Preferably, the steam connecting pipe is a U-shaped pipe, and a steam flow port is provided on the lower side of the upper shell and the upper side of the lower shell, and the two steam flow ports are sealed and connected to the steam connecting pipe through flanges.

[0014] Preferably, a condensate flow outlet is provided on the lower side of the upper shell and the upper side of the lower shell, and the two condensate flow outlets are connected to a condensate connecting pipe through a flange seal.

[0015] Preferably, the heat exchange area margins of the upper steam-water heat exchanger and the lower steam-water heat exchanger are both not less than 10%.

[0016] Compared with the prior art, the utility model has achieved the following technical effects:

[0017] The utility model adopts a two-section connection form to connect the upper and lower sections of the heat exchanger and is used to transport a mixture of steam and condensed water. From the maintenance point of view, the heat exchanger can be quickly disassembled and installed, reducing the difficulty of cleaning the tube bundle blockage; under the premise of ensuring the heat exchange area, the outer dimensions of the heat exchanger are reasonably designed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of a vertical double-section fixed tube sheet steam-water heat exchanger in an embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the internal structure of the vertical double-section fixed tube sheet steam-water heat exchanger in the embodiment of the utility model;

[0021] In the figure: 1-raw water outlet, 2-upper head, 3-head flange, 4-steam inlet, 5-condensate connecting pipe, 6-baffle, 7-steam flow port, 8-steam connecting pipe, 9-anti-impact plate, 10-lower head, 11-raw water inlet, 12-support seat, 13-tube sheet, 14-tube box, 15-heat exchange tube, 16-condensate outlet, 17-upper shell, 18-lower shell, 19-observation port. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The utility model aims to provide a vertical double-section fixed tube sheet steam-water heat exchanger to solve the problems existing in the prior art, so that the tube bundle can be quickly disassembled and assembled, and the difficulty of cleaning and repairing the tube bundle is reduced.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] like Figure 1 to Figure 2As shown, in this embodiment, a vertical double-section fixed tube sheet steam-water heat exchanger is provided, including an upper steam-water heat exchanger and a lower steam-water heat exchanger. The middle parts of the upper steam-water heat exchanger and the lower steam-water heat exchanger are connected through a pipe box 14 to connect the heat exchange tube bundles of the two steam-water heat exchangers, and the shell tubes of the two steam-water heat exchangers are connected through a steam connecting pipe 8. The upper head 2 of the upper steam-water heat exchanger is provided with a raw water outlet 1, and the upper shell 17 is provided with a steam inlet 4. The lower head 10 of the lower steam-water heat exchanger is provided with a raw water inlet 11, and the lower shell 18 is provided with a condensed water outlet 16. The vertical double-section fixed tube sheet steam-water heat exchanger of this embodiment adopts a two-section connection form, which is suitable for the rapid disassembly, cleaning and installation of the heat exchanger during annual maintenance.

[0026] As an optional solution, in this embodiment, the upper head 2 and the upper shell 17, and the lower head 10 and the lower shell 18 are connected by the head flange 3 and all pressure-bearing connecting welds adopt a full penetration structure. The material of the upper head 2 and the lower head 10 are both 304 stainless steel.

[0027] As an optional solution, in this embodiment, both ends of the upper shell 17 and the lower shell 18 are sealed and welded with tube sheets 13, and the tube sheets 13 are made of 16Mn forging / 304 stainless steel composite plates with a thickness of 3 mm.

[0028] As an optional solution, in this embodiment, a plurality of heat exchange tubes 15 are evenly distributed in the heat exchange tube bundle, and the ends of the heat exchange tubes 15 all penetrate the tube sheet 13 and are welded to the tube sheet 13 by tungsten inert gas arc welding, and the heat exchange tubes 15 are 304 stainless steel straight tubes. Seamless heat exchange tube bundles are not allowed to be spliced, and the tube wall is welded to the through hole on the tube sheet 13, and is consistent with the expansion coefficient of the shell; not only to meet the on-site production conditions and actual operation conditions, but also to fully consider that the heat exchange area margin is not less than 10% (the heat exchange area margin is related to the size and length of the heat exchange tube), so that the heat exchanger can still ensure that the maximum heat exchange capacity meets the use requirements in the case of tube blockage.

[0029] As an optional solution, in this embodiment, two baffles 6 are provided in the shells of the upper steam-water heat exchanger and the lower steam-water heat exchanger, and a support seat 12 is provided on the lower shell 18. The support seat 12 is used to fix and support the entire heat exchanger. The shell side of the steam-water heat exchanger is used to transport a mixture of steam and condensed water. The baffles 6 can increase the heat exchange formation, thereby improving the heat exchange efficiency.

[0030] As an optional solution, in this embodiment, an anti-impact plate 9 is provided in the steam inlet 4 to prevent the shell-side steam from impacting the heat exchange tube 15, thereby extending the service life of the equipment.

[0031] As an optional solution, the pipe box 14 in this embodiment is a cavity formed by sealingly connecting two end flanges 3, and the two ends of the cavity are connected to the heat exchange tube bundle. The pipe box 14 allows the liquid in the upper heat exchange tube 15 and the lower heat exchange tube 15 to pass through, and is used to transport the heated medium. When an individual tube bundle is blocked, there is a design of an intermediate header, and the liquid can flow through other tube bundles inside, which can ensure that the overall efficiency of the heat exchanger does not drop drastically.

[0032] As an optional solution, the steam coupling 8 in this embodiment is a U-shaped tube, and a steam flow port 7 is provided on the lower side of the upper shell 17 and the upper side of the lower shell 18, and the two steam flow ports 7 are sealed and connected to the steam coupling 8 through flanges. This embodiment adopts a two-stage connection form, connecting the upper and lower heat exchangers and a header for conveying a mixture of steam and condensed water, so that the heat exchanger can be quickly disassembled and installed from a maintenance perspective, reducing the difficulty of cleaning the tube bundle blockage; on the premise of ensuring the heat exchange area, the outer dimensions of the heat exchanger are reasonably designed.

[0033] As an optional solution, in this embodiment, a condensate flow outlet is provided on the lower side of the upper shell 17 and the upper side of the lower shell 18. The two condensate flow outlets are connected to a condensate connecting pipe 5 through a flange seal to facilitate the backflow of condensate in the upper shell 17.

[0034] As an optional solution, the heat exchange area margin of the upper steam-water heat exchanger and the lower steam-water heat exchanger in this embodiment is not less than 10%. The upper shell 17 and the lower shell 18 are both provided with observation ports 19 to facilitate observation of the effect of chemical cleaning in the shell.

[0035] This embodiment also provides a method for manufacturing a vertical double-section fixed tube sheet steam-water heat exchanger. First, the heat exchange tube 15 is welded to the tube sheet 13, and then installed in the upper shell 17 and the lower shell 18 of the heat exchanger respectively. After the welding is completed, the upper and lower shells are assembled, and then the upper head 2, the lower head 10, the tube box 14, and the steam and condensate water connecting pipe 5 are assembled. During the on-site inspection, the vertical double-section fixed tube sheet steam-water heat exchanger needs to consider:

[0036] 1. Before the heat exchange tubes 15 are installed, they must be subjected to a hydraulic pressure test one by one. The hydraulic pressure test pressure should be twice the design pressure. The next step can only be carried out after the pressure test shows no leakage.

[0037] 2. The weld of pipe box 14 must be 100% ultrasonically inspected, and the qualified level of ultrasonic inspection shall be the relevant provisions of Level 1 in JB4730-94;

[0038] 3. The noise detection standard is that the noise is less than 45dB(A) at a distance of 1.0m from the outer surface of the equipment;

[0039] 4. The steam pipe box 14 and condensate coupling 5 of the heat exchanger shall be subjected to a hydraulic pressure test at a test pressure of 1.25 times the design pressure for a period of not less than 30 minutes;

[0040] 5. All pipe openings of the heat exchanger are equipped with matching flanges, fasteners, bimetallic thermometers and disc pressure gauges. The flanges are of national standards, the flange gaskets are metal spiral wound gaskets, and all bolts are high-strength bolts. There must be reliable measures at the four steam inlets of the heat exchanger to prevent thermal shock and erosion of the tube bundle by steam flow. The anti-shock and anti-erosion measures taken should facilitate steam expansion and reduce the impact on the tube bundle.

[0041] The working principle of the vertical double-section fixed tube sheet steam-water heat exchanger of this embodiment is as follows: superheated steam enters the upper shell 17 of the heat exchanger through the steam interface 4, a part of it enters the lower shell 18 through the steam connecting pipe 8, and the other part of the steam enters the lower shell 18 through the condensate connecting pipe 5 after cooling and condensation, and is finally discharged through the condensate outlet 16; the raw water to be heated enters the lower head 10 and the inside of the heat exchange tube 15 through the raw water inlet 11, realizes heat exchange with the steam, and the heated raw water is sent to the outside through the raw water outlet 1.

[0042] The vertical double-section fixed tube sheet steam-water heat exchanger of this embodiment adopts the form of two-section connection. This structural design solves two problems: on the one hand, it solves the problem that the heat exchange tube 15 with a length of more than 3 meters of the original heat exchanger is difficult to clean and block. After the heat exchanger tube bundle is blocked, the current cleaning method is mostly to extend the electric tool. According to the experience of more than ten years of operation, the excessive length of the tube bundle will greatly increase the probability of damaging the heat exchange tube 15 during cleaning; on the other hand, it solves the problem that the heat exchanger's overall heat exchange efficiency is affected by the blockage of the heat exchange tube bundle. When an individual tube bundle of this two-section heat exchanger is blocked, there is a design of an intermediate header, and the liquid can flow through other tube bundles inside, which can ensure that the overall efficiency of the heat exchanger does not drop drastically.

[0043] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A vertical double-section fixed tube sheet steam-water heat exchanger, characterized in that: It comprises an upper steam-water heat exchanger and a lower steam-water heat exchanger, wherein the middle parts of the upper steam-water heat exchanger and the lower steam-water heat exchanger connect the heat exchange tube bundles of the two steam-water heat exchangers through a pipe box, and the shell pipes of the two steam-water heat exchangers are connected through a steam connecting pipe, the upper head of the upper steam-water heat exchanger is provided with a raw water outlet, and the upper shell is provided with a steam inlet, and the lower head of the lower steam-water heat exchanger is provided with a raw water inlet, and the lower shell is provided with a condensed water outlet.

2. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: The upper head and the upper shell, as well as the lower head and the lower shell are connected via head flanges, and all pressure-bearing connecting welds adopt a full-penetration structure. The upper head and the lower head are both made of stainless steel.

3. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: Both ends of the upper shell and the lower shell are sealed and welded with tube sheets, and the tube sheets are made of stainless steel composite plates with a thickness of 3 mm.

4. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 3 is characterized in that: A plurality of heat exchange tubes are evenly distributed in the heat exchange tube bundle, the ends of the heat exchange tubes all pass through the tube sheet and are welded to the tube sheet by tungsten inert gas arc welding, and the heat exchange tubes are stainless steel straight tubes.

5. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: Baffles are arranged in the shells of the upper steam-water heat exchanger and the lower steam-water heat exchanger, and a support seat is arranged on the lower shell.

6. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: An anti-collision plate is arranged in the steam inlet.

7. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: The pipe box is a cavity formed by sealingly connecting two end flanges, and both ends of the cavity are connected to the heat exchange tube bundle.

8. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: The steam connecting pipe is a U-shaped pipe, and a steam flow opening is arranged on the lower side of the upper shell and the upper side of the lower shell. The two steam flow openings are sealed and connected to the steam connecting pipe through flanges.

9. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: A condensate flow outlet is provided on the lower side of the upper shell and the upper side of the lower shell, and the two condensate flow outlets are sealed and connected to a condensate connecting pipe through flanges.

10. The vertical double-section fixed tube sheet steam-water heat exchanger according to claim 1 is characterized in that: The heat exchange area margins of the upper steam-water heat exchanger and the lower steam-water heat exchanger are not less than 10%.

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