CN202101595U - Longitudinal flow shell-and-tube heat exchanger - Google Patents

Abstract

The utility model relates to a longitudinal flow shell-and-tube heat exchanger, which comprises a cylinder body, tube sheets are symmetrically connected on both sides of the cylinder body, tube boxes and sealing heads are symmetrically connected to the outer side of the tube sheet, and tube passes are respectively connected to the outer sides of the sealing head. Fluid inlet and tube-side fluid outlet, shell-side fluid inlet and shell-side fluid outlet are symmetrically arranged on the side wall of the cylinder close to the tube-side fluid outlet, heat exchange tube bundles are arranged axially inside the cylinder, heat exchange tube bundles and tubes Plate connection, one end of the heat exchange tube bundle is connected to the tube side fluid inlet, and the other end is connected to the tube side fluid outlet. There are baffle flat rods connected, and the baffle flat rods are divided into two or three groups to form a network arrangement, and each group of baffle flat rods is arranged in parallel and at intervals, and the baffle grid is provided with a reserved space for layered partitions. The utility model improves the heat transfer efficiency of the heat exchanger, reduces the fluid flow resistance, reduces the vibration of the tube bundle and reduces the operation energy consumption of the heat exchanger.

Description

A longitudinal flow shell and tube heat exchanger

technical field

The utility model belongs to the technical field of heat exchange, in particular to a heat exchanger, more specifically to a longitudinal flow shell-and-tube heat exchanger. the

Background technique

Heat exchangers are widely used in chemical industry, fertilizer, oil refining, power, construction, food and other industrial sectors. According to the structure, heat exchangers can be divided into partition wall heat exchangers and hybrid heat exchangers. Among them, the shell-and-tube (also known as shell-and-tube) heat exchanger is the most typical partitioned wall heat exchanger. It has a long history of industrial application and still occupies a dominant position in all heat exchangers. The shell and tube heat exchanger is mainly composed of shell, tube bundle, tube sheet and head. The shell is mostly circular, with parallel tube bundles inside, and the two ends of the tube bundle are fixed on the tube sheet. Two fluids that exchange heat in the shell-and-tube heat exchanger, one flows in the tube, and its stroke is called the tube side; the other flows outside the tube, and its stroke is called the shell side. The wall of the tube bundle is the heat transfer surface. In order to improve the heat transfer coefficient of the fluid outside the tube, a certain number of transverse baffles are usually installed in the shell. The baffle plate can not only prevent the short circuit of the fluid, increase the fluid velocity, but also force the fluid to cross-flow through the tube bundle multiple times according to the prescribed path, so that the degree of turbulence is greatly increased. the

However, the shell side of the traditional shell-and-tube heat exchanger adopts a baffle (or baffle) structure, and the flow of the fluid in the shell side is a lateral flow. The thermal dead zone leads to uneven flow field and temperature field, resulting in low heat transfer efficiency of the heat exchanger and large pressure drop on the shell side, which makes this type of shell-and-tube heat exchanger require more power and material consumption, and it is easy to cause equipment damage. Issues such as corrosion and fluid-induced vibration lead to short equipment life. Therefore, the research and development of new high-efficiency energy-saving heat exchangers with high heat exchange efficiency, small fluid resistance, small size, light weight, and long service life will produce huge economic and social benefits. the

In order to solve the above problems, there are currently several related patents in China. the

Application (patent) number: 200810219873.6 Patent name: integrated finned tube heat exchanger. This patent discloses an integrated finned tube heat exchanger, which includes a shell and a tube bundle. The two ends of the shell are respectively provided with tube boxes, and the side wall of the shell is provided with a fluid inlet and a fluid outlet. The fluid inlet is located inside the shell. Equipped with a guide tube, the fluid enters the fluid inlet and distributes the longitudinal flow through the guide tube. The guide tube and the shell are welded and connected. There is a tube bundle fluid inlet, and the tube bundle is supported by several baffle grids arranged at intervals. One end of the tube bundle is connected with the tube bundle fluid inlet on the tube box, and the other end of the tube bundle is connected with the tube bundle fluid outlet on the tube box, and the tube bundle passes through the tube sheet. connect. The invention has high compactness, saves metal consumables, reduces space volume, greatly improves heat transfer coefficient, and reduces mechanical loss. the

However, the baffle grid provided by this invention uses baffle rods as supporting elements, and is limited to heat exchangers with square heat exchange tubes. For heat exchangers with triangular heat exchange tubes, the heat exchanger specified in GB151-1999 Heat pipe tube spacing conditions (for example, heat exchange tubes of Φ25mm, tube spacing of 32mm, square tube layout, the maximum gap that can pass through the baffle rod is 7mm, and when triangular tube layout is used, it can pass through the baffle rod. The maximum gap is only 2.71 mm), therefore, it is not feasible to arrange the baffle round rods according to the pipe layout method provided by the invention. the

Application (patent) number: 200920190359.4 Patent name: a double-pass separation heat exchanger. This patent designs a double-pass separation heat exchanger, including a heat exchange cylinder, a pipe box and a separator. A blocking partition, longitudinal heat exchange tubes and transverse baffle grids are arranged inside the heat exchange cylinder, and the heat exchange tubes are arranged through the gaps between the baffle rods of the baffle grids. The tube box divides the tube box into two separated spaces through the tube box partition, and the separator divides the separator into the same two spaces through the separator partition, and the tube box and the separator are connected through heat exchange tubes. The utility model can prevent clogging, and is widely used in heat exchange occasions for fluids containing solid particles and requiring high fluid velocity, and can achieve the purpose of recovering heat and avoiding clogging. the

However, the baffle grid provided by this utility model also uses baffle round rods as supporting elements, which is also not suitable for heat exchangers in which the heat exchange tubes are arranged in a triangle. the

Utility model content

In order to solve the above existing problems, the purpose of this utility model is to provide a kind of heat transfer tube bundle with different enhanced heat transfer according to different heat transfer modes (no phase change, condensation with phase change and boiling heat transfer with phase change). Different baffle grids are selected for different tube layout forms of heat exchange tubes, and single shell side or double shell side are selected according to the needs of the shell side, thereby greatly improving the heat transfer efficiency of the existing heat exchanger, reducing fluid flow resistance, and reducing tube bundles. A longitudinal flow shell and tube heat exchanger that vibrates, accelerates the average flow velocity of the shell side, and reduces the operating energy consumption and equipment investment of the existing heat exchanger. the

In order to achieve the above purpose, the utility model adopts the following technical scheme: a longitudinal flow shell-and-tube heat exchanger, including a cylinder body, tube sheets are symmetrically connected to both sides of the cylinder body, and tube sheets are symmetrically connected to the outside of the tube sheet in turn. The outer side of the head is respectively connected with a tube-side fluid inlet and a tube-side fluid outlet, and the side wall of the cylinder close to the tube-side fluid outlet is symmetrically provided with a shell-side fluid inlet and a shell-side fluid outlet. A heat exchange tube bundle is arranged axially inside the cylinder, and the heat exchange tube bundle is connected to the tube plate. One end of the heat exchange tube bundle is connected with the tube side fluid inlet, and the other end is connected with the tube side fluid outlet. The heat pipe bundle is composed of heat exchange tubes, and baffle grids are arranged at axial intervals inside the cylinder, which is characterized in that:

The inner side of the baffle grid is connected with baffle flat rods, and the baffle flat rods are divided into two groups or three groups to form a network arrangement, and each group of baffle flat rods is arranged in parallel and at intervals, and the baffle rods are arranged in parallel. There are tiered dividers to reserve space. the

Among them, the purpose of setting the baffle flat bar is to use the baffle flat bar as the support element of the heat exchange tube for the heat exchanger with the heat exchange tubes arranged in a triangle, so that the longitudinal flow exchanger in the form of triangular tube arrangement with heat transfer advantages Heaters are realized, thereby significantly improving heat transfer efficiency. At the same time, considering that the thickness of the baffle flat rod is relatively thin, supporting the heat exchange tubes according to the traditional pipe layout method may cause defects such as tube bundle vibration due to insufficient support rigidity. Therefore, the utility model adopts that the baffle flat rod Two or three groups are stacked to form a network arrangement to enhance the support stiffness of each baffle, so that different forms of baffles can be selected under different support stiffness requirements. In addition, the purpose of setting the reserved space for layered partitions is to enable users to choose single shell or double shells according to the needs of the shell. The shell-side heat exchanger is a vertical-flow single-shell-side heat exchanger when the layered partition is drawn out. the

Among them, the purpose of choosing the baffle grid is to reduce the fluid flow resistance and enhance the heat transfer efficiency. the

More preferably, a layered baffle is arranged inside the cylinder along the central axis, and one end of the layered baffle is connected to the tube plate near the fluid outlet side of the tube side. The purpose of setting layered partitions is to set the longitudinal flow heat exchanger as a longitudinal flow double-shell heat exchanger, thereby improving heat transfer efficiency. the

More preferably, the heat exchange tube is a low-fin heat exchange tube. The purpose of using low-fin heat exchange tubes is to make the heat exchanger suitable for non-phase-change heat transfer, which can be used to manufacture gas-gas, gas-liquid, liquid-liquid non-phase-change heat exchangers;

The heat exchange tube can also be a spiral groove heat exchange tube, which is suitable for strengthening condensation heat transfer with phase change, and can be used to manufacture condensers;

The heat exchange tube can also be a tube with a porous surface, which is suitable for enhancing boiling heat transfer with phase change, and can be used to manufacture evaporators. the

The rough heat transfer rib surface is used to promote the turbulence of the fluid boundary layer and reduce the thickness of the bottom layer of the heat transfer stagnation, thereby enhancing the heat transfer of the boundary layer, and the heat transfer inside and outside the tube is also strengthened. the

More preferably, deflection round rods may be connected inside the deflector grid, and the deflector rods are arranged in parallel and at intervals. The purpose of setting the baffle round rods is to be used in heat exchangers with square heat exchange tubes, thereby improving heat transfer efficiency. the

The utility model provides a heat transfer tube bundle that adopts different enhanced heat transfer tube bundles according to different heat transfer modes (three forms of heat transfer without phase change, condensation with phase change, and boiling heat transfer with phase change), and is selected according to different tube layout forms of heat exchange tubes. Different baffles, single shell side or double shell side can be selected according to the needs of the shell side, thus greatly improving the heat transfer efficiency of the existing heat exchanger, reducing fluid flow resistance, reducing tube bundle vibration, accelerating the average flow velocity of the shell side and reducing Operational energy consumption and equipment investment of existing heat exchangers for longitudinal flow shell and tube heat exchangers. the

Description of drawings

Fig. 1 is a structural schematic diagram of a longitudinal flow shell-and-tube heat exchanger provided by the present invention. the

Figure 2 is a schematic diagram of the baffle grid. the

Fig. 3 is a schematic diagram of a horizontally supported baffle grid in which the heat exchange tubes are arranged in a square shape. the

Fig. 4 is a schematic diagram of a vertically supported baffle grid in which heat exchange tubes are arranged in a square shape. the

Fig. 5 is a schematic diagram of a hexagonally supported baffle grid in which the heat exchange tubes are arranged in a triangular manner. the

Fig. 6 is a schematic diagram of a quadrangularly supported baffle grid in which the heat exchange tubes are arranged in a triangular shape. the

Fig. 7 is a schematic diagram of a low-fin heat exchange tube. the

Fig. 8 is a schematic diagram of a spiral groove heat exchange tube. the

Fig. 9 is a schematic diagram of a superficially porous tube. the

In the figure, 1. Cylinder 2. Tube box 3. Tube sheet 4. Baffle grid 5. Layered partitions 6. Heat exchange tube bundle 7. Shell side fluid inlet 8. Shell side fluid outlet 9. Head 10. Tube-side fluid inlet 11, tube-side fluid outlet 12, baffle flat rod 13, layered partition 14, heat exchange tube 15, baffle rod 16, reserved space for layered partition. the

Detailed ways

The specific embodiment of the utility model will be further described below in conjunction with the accompanying drawings. This embodiment is only a description of the best implementation mode of the utility model, and does not limit the scope of the utility model in any way. the

The connection mode of the longitudinal flow shell-and-tube heat exchanger in the utility model is as follows:

As shown in Fig. 1, tube plates 3 are symmetrically connected to both sides of the cylinder body 1, and the outer sides of the tube plate 3 are symmetrically connected to the tube box 2 and the head 9 in turn, and the outer sides of the head 9 are respectively connected to the tube-side fluid inlets 10. and the tube-side fluid outlet 11, the side wall of the cylinder 1 close to the tube-side fluid outlet 11 is symmetrically provided with a shell-side fluid inlet 7 and a shell-side fluid outlet 8, and the inside of the cylinder 1 is axially provided with heat exchange tubes Tube bundle 6, the heat exchange tube bundle 6 is connected to the tube sheet 3, one end of the heat exchange tube bundle 6 communicates with the tube-side fluid inlet 10, and the other end communicates with the tube-side fluid outlet 11, and the inner axial direction of the cylinder body 1 Baffles 4 are arranged at intervals, and layered partitions 13 are arranged inside the cylinder body 1 along the central axis, and one end of the layered partitions 13 is connected to the tube sheet 3 near the side of the tube-side fluid outlet 11 . the

As shown in Figure 2, the inner side of the baffle grid 4 is connected with a baffle flat bar 12, and the baffle flat bar 12 is divided into two groups (see Figure 6) or three groups (see Figure 5) to form a network arrangement, Each group of baffle flat rods 12 is arranged in parallel and at intervals, and the baffle grid 4 is also provided with a reserved space 16 for layered partitions, and the layered partitions 13 pass through the reserved spaces 16 for layered partitions. the

The utility model proposes different forms of baffled flat bar-type baffle grids 4 for triangular tube layouts with different pipe diameters. When the outer diameter of the heat exchange tube 14 is below 12 mm, the hexagonal support type baffle grid 4 is used ( See Fig. 5), its baffle flat bars 12 are arranged in three adjacent planes in three groups with different inclinations, and are arranged in a net shape, and each group of baffle flat bars 12 is arranged in parallel and at intervals; for heat exchange tubes 14 When the outer diameter is more than 14 mm, the four-sided supporting baffle grid 4 (see Figure 6) is used, and the baffle flat rods 12 are arranged in two adjacent planes in two groups with different inclinations, and are arranged in a net shape. Likewise, each group of baffle flat rods 12 is arranged in parallel and at intervals. the

If the heat exchange tubes 14 are the baffle grid 4 of the square pipe layout, its baffle round rods 15 can be arranged at horizontal intervals (seeing Fig. 3) or vertically at intervals (seeing Fig. 4). the

The baffle flat bar 12 or baffle round bar 15 is used to support the heat exchange tube 14, so that the fluid in the shell side of the heat exchanger changes from horizontal flow to parallel (longitudinal) flow, which not only greatly reduces the heat transfer dead zone, but also greatly The amplitude reduces the shell-side pressure drop lost by the fluid due to repeated baffles, and can obtain a higher heat transfer film coefficient with a lower fluid delivery work. the

Simultaneously, heat exchange tube 14 can adopt low-fin heat exchange tube (see Fig. 7) to be suitable for non-phase-change heat transfer, can be used for manufacturing gas-gas, gas-liquid, liquid-liquid non-phase-change heat exchanger;

The heat exchange tube 14 can also be selected as a spiral groove heat exchange tube (see Figure 8), which is suitable for strengthening the condensation heat transfer with phase change, and can manufacture a condenser;

The heat exchange tube 14 can also be a tube with a porous surface (see FIG. 9 ), which is suitable for enhancing boiling heat transfer with phase change, and can be used to manufacture an evaporator. the

The rough heat transfer rib surface is used to promote the turbulence of the fluid boundary layer and reduce the thickness of the bottom layer of the heat transfer stagnation, thereby enhancing the heat transfer of the boundary layer, and the heat transfer inside and outside the tube is also strengthened. the

In the longitudinal flow shell-and-tube heat exchanger provided above, the fluid flow direction is longitudinal flow, that is, parallel to the heat exchange tube bundle 6, and the shell-side heat transfer is enhanced, the heat transfer film coefficient is increased by 30%; the shell-side resistance is reduced Reduced by 35%; improve the overall heat transfer performance of the shell side, so that (αo/ΔP) increased by 50%; reduce the weight of the equipment by about 40%; corrosion resistance, long service life. the

Claims (6)

1. A longitudinal flow shell-and-tube heat exchanger, comprising a cylinder (1), the two sides of the cylinder (1) are symmetrically connected with tube sheets (3), and the outside of the tube sheet (3) is symmetrically connected with Pipe box (2), head (9), the outer side of the head (9) is respectively connected with the tube-side fluid inlet (10) and the tube-side fluid outlet (11), and the cylinder (1) is close to the tube-side fluid A shell-side fluid inlet (7) and a shell-side fluid outlet (8) are arranged symmetrically on the side wall at one end of the outlet (11), and a heat exchange tube bundle (6) is arranged axially inside the cylinder (1). The heat pipe bundle (6) is connected to the tube sheet (3), one end of the heat exchange tube bundle (6) communicates with the tube-side fluid inlet (10), and the other end communicates with the tube-side fluid outlet (11), the heat exchange tube bundle (6) The tube bundle (6) is composed of heat exchange tubes (14), and the inside of the cylinder (1) is provided with baffle grids (4) at intervals in the axial direction, which is characterized in that: The inner side of the baffle grid (4) is connected with a baffle flat bar (12), The baffle flat rods (12) are stacked in two or three groups to form a mesh arrangement, and each group of baffle flat rods (12) is arranged in parallel and at intervals, A reserved space (17) for layered partitions is arranged inside the baffle grid (4). 2. A longitudinal flow shell-and-tube heat exchanger according to claim 1, characterized in that: a layered partition (13) is arranged inside the cylinder (1) along the central axis, and the layered partition One end of the plate (13) is connected to the tube plate (3) on the side close to the tube-side fluid outlet (11). 3. A longitudinal flow shell-and-tube heat exchanger according to claim 1, characterized in that: the heat exchange tube (14) is a low-fin heat exchange tube. 4. A longitudinal flow shell-and-tube heat exchanger according to claim 1, characterized in that: the heat exchange tube (14) is a spiral groove heat exchange tube. 5. A longitudinal flow shell-and-tube heat exchanger according to claim 1, characterized in that: the heat exchange tube (14) is a tube with a porous surface. 6. A longitudinal flow shell-and-tube heat exchanger according to claim 1, characterized in that: a baffle rod (15) can be connected inside the baffle grid (4), and the baffle rod (15) Parallel interval setting.

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