Double-pipe heat exchanger with bidirectional spiral flow channel and working method of double-pipe heat exchanger

Abstract

The invention relates to a double-pipe heat exchanger with two-way spiral flow channels and a working method of the double-pipe heat exchanger. The double-pipe heat exchanger comprises a first pipe box, a second pipe box and a pipe bundle section. An inner tube and a plurality of sleeves are arranged in the tube bundle section; spiral fins are respectively arranged between the inner tube and the adjacent sleeve, between the sleeves and between the outermost sleeve and the outer wall of the tube bundle section, and a plurality of spiral runners are formed in the tube bundle section; a first partition plate, a first medium inlet and a second medium outlet are arranged in the middle of the first tube box. A second partition plate, a second medium inlet and a first medium outlet are arranged in the middle of the second pipe box. The first heat exchange medium and the second heat exchange medium conduct countercurrent flow heat exchange through the corresponding spiral flow channels, the heat exchange area is large, the heat exchange efficiency is high, the structure is simple, and manufacturing is convenient.

Description

Technical Field

[0001] The present invention relates to a shell and tube heat exchanger, in particular to a shell and tube heat exchanger with a bidirectional spiral flow channel and a working method thereof. Background Art

[0002] A shell-and-tube heat exchanger is a common wall-type heat exchange device consisting of concentric or eccentric tubes. In a conventional shell-and-tube heat exchanger, the hot and cold fluids flow through the inner and outer tubes, respectively, exchanging heat through the tube walls. Its basic structure includes an inner tube (which serves as a flow path for high-temperature fluids such as steam and hot water), an outer tube (i.e., a casing, which wraps around the outside of the inner tube and serves as a flow path for low-temperature fluids such as cold water and air), and connecting components such as U-shaped elbows and flanges, which are used to extend the flow path or connect multiple sets of tubes in series. Typically, shell-and-tube heat exchangers use countercurrent flow (the two fluids flow in opposite directions) to improve heat transfer efficiency. The advantages of a shell-and-tube heat exchanger are its simple structure, easy disassembly and cleaning, ability to withstand high pressures, suitability for high temperature differential conditions, and high heat transfer efficiency (especially when countercurrent is used). The disadvantage is its small heat transfer area per unit volume.

[0003] The petrochemical standard SH-T 3119-2000, "Design Specifications for Steel Tube Heat Exchangers for Petrochemical Industry," lists the structures of single-tube and multi-tube heat exchangers. Single-tube heat exchangers utilize return elbows, which are difficult to manufacture and result in a small heat transfer area. Multi-tube heat exchangers utilize U-shaped connecting pipes and tubesheets for heat transfer tubes, which are also difficult to manufacture and have low heat transfer efficiency. Summary of the Invention

[0004] The present invention provides a shell and tube heat exchanger with bidirectional spiral flow channels and an operating method thereof. The shell and tube heat exchanger adopts a structure in which spiral fins are arranged between a coaxially arranged inner tube and multiple shells, and multiple spiral flow channels are formed in the tube bundle section of the heat exchanger. Heat exchange medium 1 and heat exchange medium 2 are countercurrently exchanged through the corresponding spiral flow channels, resulting in a large heat exchange area, high heat exchange efficiency, simple structure, and easy production.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A shell and tube heat exchanger with a bidirectional spiral flow channel comprises a shell and tube heat exchanger consisting of a tube box 1, a tube box 2 and a tube bundle section; the tube bundle arranged in the tube bundle section comprises an inner tube arranged at the center and a plurality of tubes arranged coaxially with the inner tube; spiral fins are respectively arranged between the inner tube and adjacent tubes, between each tube, and between the outermost tube and the outer wall of the tube bundle section, forming multiple spiral flow channels in the tube bundle section; the inner tube extends into the tube box 1 and the tube box 2; a partition 1 is provided in the middle of the tube box 1, dividing the tube box 1 into a medium 1 inlet area and a medium 2 outlet area, and counting from the center of the shell and tube heat exchanger outward, the medium 1 inlet area is The ends of the odd-numbered spiral flow channels in the medium 2 zone are closed by inlet plugging plate 1, and the ends of the even-numbered spiral flow channels in the medium 2 outlet zone are closed by outlet plugging plate 1. The medium 1 inlet zone is provided with medium 1 inlet, and the medium 2 outlet zone is provided with medium 2 outlet; a partition plate 2 is provided in the middle of pipe box 2 to separate pipe box 2 into medium 2 inlet zone and medium 1 outlet zone. Counting from the center of the shell and tube heat exchanger outward, the ends of the even-numbered spiral flow channels in the medium 2 inlet zone are closed by inlet plugging plate 2, and the ends of the odd-numbered spiral flow channels in the medium 1 outlet zone are closed by outlet plugging plate 2. The medium 2 inlet zone is provided with medium 2 inlet, and the medium 1 outlet zone is provided with medium 1 outlet.

[0007] The shell and tube heat exchanger is a horizontal shell and tube heat exchanger. The outer walls of tube box 1, tube box 2 and the tube bundle section are an integrated structure and together form the cylinder of the shell and tube heat exchanger. The inner tube is arranged along the axial length of the cylinder; the medium 1 inlet is arranged at the top of tube box 1, and the medium 2 outlet is arranged at the bottom of tube box 1; the medium 2 inlet is arranged at the top of tube box 2, and the medium 1 outlet is arranged at the bottom of tube box 2; supports are provided on both sides of the bottom of the tube bundle section.

[0008] The outer end of the pipe box one is provided with two semicircular end plugging plates one, which are welded to the inner pipe and the inner wall of the pipe box one along the circumferential direction respectively; a circular cover plate one is provided on the outer side of the two end plugging plates one, which is welded to the end plugging plate one and the inner pipe to achieve the blocking of the corresponding ends of the cylinder and the inner pipe; the outer end of the pipe box two is provided with two semicircular end plugging plates two, which are welded to the inner pipe and the inner wall of the pipe box two along the circumferential direction respectively; a circular cover plate two is provided on the outer side of the two end plugging plates two, which is welded to the end plugging plate two and the inner pipe to achieve the blocking of the corresponding ends of the cylinder and the inner pipe.

[0009] A working method of a shell-and-tube heat exchanger with bidirectional spiral flow channels, wherein heat exchange medium 1 enters the medium 1 inlet area at the upper portion of tube box 1 from medium 1 inlet, flows through a tube bundle section through multiple spaced spiral flow channels, and then enters the medium 1 outlet area at the lower portion of tube box 2, and then flows out through the medium 1 outlet; heat exchange medium 2 enters the medium 2 inlet area at the upper portion of tube box 2 from medium 2 inlet, flows through the tube bundle section through multiple spaced spiral flow channels, and then enters the medium 2 outlet area at the lower portion of the tube box, and then flows out through the medium 2 outlet; heat exchange medium 1 and heat exchange medium 2 flow in counter-current directions in the multiple spaced spiral flow channels for heat exchange.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1) The structure of spiral fins arranged between the coaxial inner tube and multiple sleeves is adopted to form multiple spiral flow channels in the tube bundle section of the heat exchanger. Heat exchange medium 1 and heat exchange medium 2 exchange heat in countercurrent through the corresponding spiral flow channels, resulting in a large heat exchange area and high heat exchange efficiency;

[0012] 2) Using a small radius spiral flow channel to make the medium flow in a circular manner, flushing the inner and outer walls of the spiral flow channel (including the inner wall of the cylinder and the outer wall of the inner tube) to achieve a self-cleaning effect;

[0013] 3) The spiral fins not only increase the heat exchange area as fins, but also guide the medium to flow along the spiral flow channel. At the same time, they also serve as supports between the casings, that is, they have a self-supporting structure. Compared with conventional casing heat exchangers, the heat exchange tubes can be designed to be longer, increasing the heat exchange area.

[0014] 4) The shell and tube heat exchanger adopts a welded structure as a whole, with good sealing performance; there is no tube sheet, which is easy to manufacture and install. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the shell and tube heat exchanger with bidirectional spiral flow channels according to the present invention.

[0016] Figure 2 yes Figure 1 A-direction view in.

[0017] Figure 3 yes Figure 1 BB view in .

[0018] Figure 4 yes Figure 1 CC view in .

[0019] Figure 5 It is a schematic diagram of the connection relationship between the spiral fin and the sleeve of the present invention.

[0020] Figure 6 It is a structural schematic diagram of the end blocking plate 1 (end blocking plate 2) described in the present invention.

[0021] In the figure: 1. Pipe box 1 1-1. Medium 1 inlet 1-2. Medium 2 outlet 1-3. End plug 1 1-4. Cover plate 1 1-5. Partition plate 1 2. Tube bundle 2-1. Inner tube 2-2. Casing 2-3. Spiral fin 2-4. Inlet plug 1 2-5. Outlet plug 1 2-6. Inlet plug 2 2-7. Outlet plug 2 3. Pipe box 2 3-1. Medium 2 inlet 3-2. Medium 1 outlet 3-3. End plug 2 3-4. Cover plate 2 3-5. Partition plate 2 4. Support DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0023] like Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 As shown, the present invention discloses a double-tube heat exchanger with a bidirectional spiral flow channel, comprising a double-tube heat exchanger consisting of a tube box 1, a tube box 2 3 and a tube bundle section 2; the tube bundle arranged in the tube bundle section 2 comprises an inner tube 2-1 arranged at the center, and a plurality of tubes 2-2 arranged coaxially with the inner tube 2-1; spiral fins 2-3 are respectively arranged between the inner tube 2-1 and the adjacent tubes 2-2, between each tube 2-2, and between the outermost tube 2-2 and the outer wall of the tube bundle section 2, forming a plurality of spiral flow channels in the tube bundle section 2; the inner tube 2-1 extends into the tube box 1 and the tube box 2 3; a partition 1-5 is provided in the middle of the tube box 1 to separate the tube box 1 into a medium 1 inlet area and a medium 2 outlet area, from the center of the double-tube heat exchanger Counting outward, the ends of the odd-numbered spiral flow channels in the medium 1 inlet zone are closed by an inlet plugging plate 2-4, and the ends of the even-numbered spiral flow channels in the medium 2 outlet zone are closed by an outlet plugging plate 2-5. The medium 1 inlet zone is provided with a medium 1 inlet 1-1, and the medium 2 outlet zone is provided with a medium 2 outlet 1-2. A partition plate 2-5 is provided in the middle of the pipe box 2-3 to separate the pipe box 2-3 into the medium 2 inlet zone and the medium 1 outlet zone. Counting outward from the center of the shell and tube heat exchanger, the ends of the even-numbered spiral flow channels in the medium 2 inlet zone are closed by an inlet plugging plate 2-6, and the ends of the odd-numbered spiral flow channels in the medium 1 outlet zone are closed by an outlet plugging plate 2-7. The medium 2 inlet zone is provided with a medium 2 inlet 3-1, and the medium 1 outlet zone is provided with a medium 1 outlet 3-2.

[0024] like Figure 1 As shown, the shell and tube heat exchanger is a horizontal shell and tube heat exchanger. The outer wall of the tube box 1, the tube box 2 3 and the tube bundle section 2 are an integrated structure and together form the cylinder of the shell and tube heat exchanger. The inner tube 2-1 is arranged along the axial length of the cylinder; the medium 1 inlet 1-1 is arranged at the top of the tube box 1, and the medium 2 outlet 1-2 is arranged at the bottom of the tube box 1; the medium 2 inlet 3-1 is arranged at the top of the tube box 2 3, and the medium 1 outlet 3-2 is arranged at the bottom of the tube box 2 3; supports 5 are provided on both sides of the bottom of the tube bundle section 2.

[0025] like Figure 1 、 Figure 2 、 Figure 6As shown, the outer end of the pipe box 1 is provided with two semicircular end plugging plates 1-3, and the end plugging plates 1-3 are welded to the inner tube 2-1 and the inner wall of the pipe box 1 along the circumferential direction respectively; the outer sides of the two end plugging plates 1-3 are provided with a circular cover plate 1-4, and the cover plate 1-4 is welded to the end plugging plates 1-3 and the inner tube 2-1 to achieve the blocking of the corresponding ends of the cylinder and the inner tube 2-1; the outer end of the pipe box 23 is provided with two semicircular end plugging plates 23-3, and the end plugging plates 23-3 are welded to the inner tube 2-1 and the inner wall of the pipe box 23 along the circumferential direction respectively; the outer sides of the two end plugging plates 23-3 are provided with a circular cover plate 23-4, and the cover plate 23-4 is welded to the end plugging plates 23-3 and the inner tube 2-1 to achieve the blocking of the corresponding ends of the cylinder and the inner tube 2-1.

[0026] The present invention discloses an operating method for a shell-and-tube heat exchanger with bidirectional spiral flow channels. Heat exchange medium 1 enters the medium 1 inlet area at the top of tube box 1 from medium 1 inlet 1-1, flows through tube bundle section 2 through multiple spaced spiral flow channels, and then enters the medium 1 outlet area at the bottom of tube box 2 3, and then flows out through medium 1 outlet 3-2. Heat exchange medium 2 enters the medium 2 inlet area at the top of tube box 2 3 from medium 2 inlet 3-1, flows through tube bundle section 2 through multiple spaced spiral flow channels, and then enters the medium 2 outlet area at the bottom of tube box 1 1, and then flows out through medium 2 outlet 1-2. Heat exchange medium 1 and heat exchange medium 2 flow in counter-current directions in the multiple spaced spiral flow channels for heat exchange.

[0027] The present invention discloses a double-tube heat exchanger with bidirectional spiral flow channels, comprising a tube box 1, a tube bundle section 2, and a tube box 2 3. Tube bundle section 2 is equipped with inner tubes 2-1, tubes 2-1, and spiral fins 2-3. Tube box 1 is equipped with a medium inlet 1-1, a medium outlet 1-2, a partition 1-5, an end plugging plate 1-3, and a cover plate 1-4. Tube box 2 is equipped with a medium inlet 3-1, a medium outlet 3-2, a partition 3-5, an end plugging plate 3-3, and a cover plate 3-4. The double-tube heat exchanger is preferably horizontal, with a support 4 provided at the bottom of tube bundle section 2.

[0028] The inner tube 2-1 is preferably a seamless steel tube, and both ends of the inner tube 2-1 are sealed by welding with the cover plate 1-4 and the cover plate 2-4; a plurality of sleeves 2-2 are coaxially arranged on the periphery of the inner tube 2-1, and spiral fins 2-3 are welded between the inner tube 2-1 and the innermost sleeve 2-2, between two adjacent sleeves 2-1, and between the outermost sleeve 2-2 and the outer wall of the tube bundle section 2 (i.e., the cylinder), and the axial length of the spiral fins 2-3 is consistent with the length of the sleeve 2-2.

[0029] In the shell and tube heat exchanger of the present invention, the spiral fins 2-3 serve as conventional fins to increase the heat exchange area and guide the medium to flow along the spiral flow channel, and also serve as support between the inner tube 2-1, the sleeve 2-2 and the cylinder that form each spiral flow channel.

[0030] In the shell-and-tube heat exchanger of the present invention, heat exchange medium 1 enters from the upper space of tube box 1 into a plurality of spaced spiral flow channels, such as odd-numbered spiral flow channels (counted from the center outward), and the flow direction of heat exchange medium 1 in the odd-numbered spiral flow channels is forward; while heat exchange medium 2 enters from the upper space of tube box 2 3 into a plurality of spaced spiral flow channels, such as even-numbered spiral flow channels (counted from the center outward), which are staggered with heat exchange medium 1, and the flow direction of heat exchange medium 2 in the even-numbered spiral flow channels is reverse; that is, heat exchange medium 1 and heat exchange medium 2 flow and exchange heat in a plurality of spaced bidirectional spiral flow channels, thereby greatly increasing the heat exchange area.

[0031] A partition 1-5 is installed in the middle of pipe box 1 to separate heat exchange medium 1 (inflow) from heat exchange medium 2 (outflow). Similarly, a partition 2-3-5 is installed in the middle of pipe box 2-3 to separate heat exchange medium 2 (inflow) from heat exchange medium 1 (outflow). Partitions 1-5 and 2-3-5 are welded to inner tube 2-1, the cylinder, the corresponding plugging plates (including inlet plugging plate 1-4, outlet plugging plate 1-5, inlet plugging plate 2-6, and outlet plugging plate 2-7), and the corresponding end plugging plates (including end plugging plate 1-3 and end plugging plate 2-3).

[0032] In the double-tube heat exchanger described herein, the barrel 2-1, serving as the heat exchanger's outer shell, is a monolithic structure. It can be considered the outer wall of the tube bundle 2, extending outwards to form the outer walls of tube box 1 and tube box 2, 3. The inner tube 2-1 is also a monolithic steel tube. It can be considered the inner tube 2-1 of the tube bundle 2, extending outwards into tube box 1 and tube box 2, 3. The inner tube section within tube box 1 and tube box 2, 3, is not equipped with spiral fins 2-3.

[0033] The spiral flow channel connecting medium 1 inlet 1-1 and medium 1 outlet 3-2 serves as a channel for heat exchange medium 1, flowing along spiral fins 2-3 within the corresponding spiral flow channel. The spiral flow channel connecting medium 2 inlet 3-1 and medium 2 outlet 1-2 serves as a channel for heat exchange medium 2, flowing along spiral fins 2-3 within the corresponding spiral flow channel. This means that heat exchange mediums 1 and 2 exchange indirectly through spiral fins 2-3 in countercurrent, increasing the heat exchange area.

[0034] The material of the shell and tube heat exchanger of the present invention is determined according to the corrosiveness of the first heat exchange medium and the second heat exchange medium.

[0035] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A double-tube heat exchanger with a bidirectional spiral flow channel, comprising a double-tube heat exchanger consisting of a first tube box, a second tube box, and a tube bundle section; characterized in that: The tube bundle arranged in the tube bundle section includes an inner tube arranged at the center and a plurality of sleeves arranged coaxially with the inner tube; spiral fins are respectively arranged between the inner tube and adjacent sleeves, between each sleeve, and between the outermost sleeve and the outer wall of the tube bundle section, forming multiple spiral flow channels in the tube bundle section; the inner tube extends to tube box 1 and tube box 2; a partition plate 1 is provided in the middle of tube box 1 to separate tube box 1 into a medium 1 inlet area and a medium 2 outlet area. Counting from the center of the shell and tube heat exchanger outward, the odd-numbered spiral flow channel ends of the medium 1 inlet area are closed by an inlet blocking plate 1. The ends of the even-numbered spiral flow channels in the medium 2 outlet zone are closed by outlet plugging plate 1, the medium 1 inlet is provided in the medium 1 inlet, and the medium 2 outlet is provided in the medium 2 outlet; partition plate 2 is provided in the middle of pipe box 2 to separate pipe box 2 into the medium 2 inlet zone and the medium 1 outlet zone. Counting outward from the center of the shell and tube heat exchanger, the ends of the even-numbered spiral flow channels in the medium 2 inlet zone are closed by inlet plugging plate 2, the ends of the odd-numbered spiral flow channels in the medium 1 outlet zone are closed by outlet plugging plate 2, the medium 2 inlet zone is provided with medium 2 inlet, and the medium 1 outlet zone is provided with medium 1 outlet.

2. The double-tube heat exchanger with bidirectional spiral flow channels according to claim 1, characterized in that: The shell and tube heat exchanger is a horizontal shell and tube heat exchanger. The outer walls of tube box 1, tube box 2 and the tube bundle section are an integrated structure and together form the cylinder of the shell and tube heat exchanger. The inner tube is arranged along the axial length of the cylinder; the medium 1 inlet is arranged at the top of tube box 1, and the medium 2 outlet is arranged at the bottom of tube box 1; the medium 2 inlet is arranged at the top of tube box 2, and the medium 1 outlet is arranged at the bottom of tube box 2; supports are provided on both sides of the bottom of the tube bundle section.

3. The double-tube heat exchanger with bidirectional spiral flow channels according to claim 1, characterized in that: The outer end of the pipe box one is provided with two semicircular end plugging plates one, which are welded to the inner pipe and the inner wall of the pipe box one along the circumferential direction respectively; a circular cover plate one is provided on the outer side of the two end plugging plates one, which is welded to the end plugging plate one and the inner pipe to achieve the blocking of the corresponding ends of the cylinder and the inner pipe; the outer end of the pipe box two is provided with two semicircular end plugging plates two, which are welded to the inner pipe and the inner wall of the pipe box two along the circumferential direction respectively; a circular cover plate two is provided on the outer side of the two end plugging plates two, which is welded to the end plugging plate two and the inner pipe to achieve the blocking of the corresponding ends of the cylinder and the inner pipe.

4. The operating method of a double-tube heat exchanger with a bidirectional spiral flow channel according to claim 1, 2 or 3, characterized in that: Heat exchange medium 1 enters the medium 1 inlet area at the upper part of tube box 1 from medium 1 inlet, flows through the tube bundle section through multiple spaced spiral flow channels, and then enters the medium 1 outlet area at the lower part of tube box 2, and then flows out from the medium 1 outlet; heat exchange medium 2 enters the medium 2 inlet area at the upper part of tube box 2 from medium 2 inlet, flows through the tube bundle section through multiple spaced spiral flow channels, and then enters the medium 2 outlet area at the lower part of the tube box, and then flows out from the medium 2 outlet; heat exchange medium 1 and heat exchange medium 2 flow in counter-current in the multiple spaced spiral flow channels to exchange heat.

Images