CN113028863A

CN113028863A - J-shaped baffle plate heat exchanger

Info

Publication number: CN113028863A
Application number: CN202110150681.XA
Authority: CN
Inventors: 孙正杨; 李伯奎; 冯国峰; 王玲; 许兆美
Original assignee: Huaiyin Institute of Technology
Current assignee: Huaiyin Institute of Technology
Priority date: 2021-02-04
Filing date: 2021-02-04
Publication date: 2021-06-25
Anticipated expiration: 2041-02-04
Also published as: CN113028863B

Abstract

The invention relates to the technical field of heat exchangers and discloses a J-shaped baffle plate heat exchanger.A left tube box and a right tube box are respectively connected to tube plates on two sides of a barrel, a plurality of pull rods and heat exchange tubes are arranged in the barrel in parallel, one end of each pull rod is fixed on the tube plate on one side, a distance tube is sleeved on the outer wall of each pull rod, two ends of each heat exchange tube are respectively fixed on the tube plates on two sides, the distance tube is connected with a plurality of baffle plates, and the distance tube and the heat exchange tubes are respectively arranged in connecting holes of the; in the baffle plate, the upper ends of the upper J-shaped baffle plates which are arranged in pairs and symmetrically arranged are tightly attached to the surface of the top end inside the cylinder, the lower ends of the lower J-shaped baffle plates are tightly attached to the surface of the bottom end inside the cylinder, and a flow channel is formed among the upper J-shaped baffle plates, the lower J-shaped baffle plates and the cylinder. The invention improves the heat transfer coefficient of the heat exchanger, improves the heat exchange efficiency, greatly reduces the dead zone area, obviously reduces the pressure drop, improves the natural frequency of the heat exchange tube of the heat exchanger and reduces the vibration.

Description

J-shaped baffle plate heat exchanger

Technical Field

The invention relates to the technical field of heat exchangers, in particular to a J-shaped baffle plate heat exchanger.

Background

The heat exchanger is widely applied to various industrial fields such as chemical industry, petroleum, energy, power, metallurgy, refrigeration, transportation and the like, has the main functions of completing heat exchange and waste heat utilization in the technical process, and has remarkable influences on investment, energy consumption, safe and economic operation, pollutant emission and the like of the industrial process due to the advantages and disadvantages of heat transfer and fluid flow performance. The shell-and-tube heat exchanger is used most in the heat exchanger, and the application technology is the most mature.

The baffle plate is a key component of the shell-and-tube heat exchanger, and can separate a shell pass space besides the function of supporting the heat exchange tube bundle, so that fluid is blocked when flowing in the shell pass, the turbulence degree is increased, and the shell pass fluid of the heat exchanger flows to generate expected flow shape and flow velocity, thereby improving the heat transfer coefficient. The shell side pressure drop of the traditional baffle plate heat exchanger is large, a plurality of flow dead zones exist, the heat exchange is insufficient, and the pressure drop loss is large. Meanwhile, the high-speed fluid transversely scours the tube bundle to easily generate induced vibration, the heat transfer tube is seriously abraded, and the whole service life of the heat exchanger is shortened.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides the J-shaped baffle plate heat exchanger which is simple, ingenious and reasonable in structure, the flow direction of shell-side fluid is periodically changed by changing the shape of the baffle plate, turbulence and heat exchange residence time are increased, the heat transfer coefficient of the heat exchanger is improved, the heat exchange efficiency is effectively improved, the dead zone area is greatly reduced, the pressure drop is obviously reduced, the inherent frequency of a heat exchange tube of the heat exchanger is improved, and the vibration is reduced.

The technical scheme is as follows: the invention provides a J-shaped baffle plate heat exchanger which comprises a barrel, a left pipe box and a right pipe box, wherein the left pipe box and the right pipe box are respectively connected to pipe plates on two sides of the barrel; the baffle plate comprises an upper layer J-shaped baffle plate and a lower layer J-shaped baffle plate, the upper end of the upper layer J-shaped baffle plate is tightly attached to the surface of the top end in the cylinder, the lower end of the lower layer J-shaped baffle plate is tightly attached to the surface of the bottom end in the cylinder, and a flow channel is formed among the upper layer J-shaped baffle plate, the lower layer J-shaped baffle plate and the cylinder.

Preferably, the upper layer of J-shaped baffle plate and the lower layer of J-shaped baffle plate are J-shaped baffle plates with the same bending radian; the upper layer J-shaped baffle plate and the lower layer J-shaped baffle plate are respectively composed of a long plate, a short plate and a connecting plate, wherein the long plate and the short plate are parallel to each other, and the connecting plate is used for connecting the long plate and the short plate.

Preferably, the joints between the long plates and the connecting plates and between the short plates and the connecting plates are provided with 40-50-degree chamfers.

Preferably, the length ratio of the long plate to the short plate is 1.5-2: 1, and the length of the short plate is larger than the radius of the cylinder. After the design, the upper and lower J-shaped baffle short plates have an intersection under Y-axis projection to form an S-shaped space, so that the flow is increased.

Preferably, the distance between the short plates in the two adjacent upper-layer J-shaped baffle plates and the lower-layer J-shaped baffle plates is 0.6-0.8 times of the diameter of the cylinder.

Has the advantages that: compared with the prior art, the J-shaped baffle plate heat exchanger has a simple structure and is ingenious and reasonable in design, the flow direction of shell-side fluid is periodically changed by changing the shape of the baffle plate into the J shape, turbulence and heat exchange residence time are increased, the heat transfer coefficient of the heat exchanger is improved, the heat exchange efficiency is effectively improved, the dead zone area is greatly reduced, the pressure drop is obviously reduced, the inherent frequency of a heat exchange tube of the heat exchanger is improved, and vibration is reduced. In practical application, the baffle plate is additionally provided with a cooling water shell pass, and turbulence is increased, so that cooling water is efficiently utilized, and the heat transfer efficiency is greatly improved.

1. The J-shaped structure has the advantages that the baffle structure is optimized, so that the velocity distribution of the internal fluid is more uniform, the maximum velocity is reduced, and the pressure drop can be reduced.

2. The fluid is blocked by the baffle plate, a vortex fluid is formed on one side of the back flow of the baffle plate, the vortex fluid can not flow out in situ to form a dead zone, but the maximum speed is reduced due to the structural optimization of the J-shaped plate and the range of forming the dead zone is reduced compared with an I-shaped and J-shaped speed distribution cloud picture.

3. Because the J-shaped plate structure is optimized, the shell pass is increased, the velocity distribution is uniform, the maximum velocity is reduced, and the pressure drop is small due to sufficient heat exchange.

4. The comparison worker's shape baffling board, J shape baffling board have more a short slab and connecting plate part than worker's shape, and be a whole, and are more firm to behind the installation J shape baffling board, on level and vertical direction, because J shape baffling board speed is more even, under the baffling board condition of arranging the same quantity, it is inseparabler to arrange, and the interval is little than worker's shape, and J shape baffling board receives fluidic impact force to compare with worker's shape littleer, so the vibration is little.

Drawings

FIG. 1 is a schematic plan view of a J-baffle heat exchanger according to the present invention;

FIG. 2 is a schematic two-dimensional structure of an upper layer J-shaped baffle plate or a lower layer J-shaped baffle plate;

FIG. 3 is a schematic perspective view of a J-baffle of the present invention;

FIG. 4 is a schematic perspective view of a prior art I-baffle heat exchanger and a J-baffle heat exchanger of the present invention;

FIG. 5 is a schematic view of the cross-sectional positions of the selected ZX and XY directions;

FIG. 6 is a cloud of velocity profiles for a prior art I-baffle heat exchanger;

FIG. 7 is a cloud of velocity profiles for a J-baffle heat exchanger according to the present invention;

FIG. 8 is a cloud view of the XY cross-sectional velocity profile of a prior art I-baffle heat exchanger;

FIG. 9 is a cloud view of the velocity distribution of the J-shaped baffle heat exchanger in XY section according to the present invention;

FIG. 10 is a cloud view of a prior art I-baffle heat exchanger with velocity vectors distributed across a 4XY cross-section;

FIG. 11 is a cloud view of velocity vector distribution on a 4XY section of a J-shaped baffle heat exchanger according to the present invention;

FIG. 12 is a cloud of temperature profiles for a prior art I-baffle heat exchanger;

FIG. 13 is a cloud of temperature profiles for a J-baffle heat exchanger according to the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

The embodiment provides a J-shaped baffle plate heat exchanger, as shown in fig. 1, the heat exchanger mainly comprises a cylinder 1, a left tube box 2 and a right tube box 3 which are respectively connected to tube plates 4 on two sides of the cylinder 1, a plurality of pull rods 5 and heat exchange tubes 6 are arranged in the cylinder 1 in parallel, one end of each pull rod 5 is fixed on the tube plate 4 on one side, a distance tube 7 is sleeved on the outer wall of each pull rod 5, two ends of each heat exchange tube 6 are respectively fixed on the tube plates 4 on two sides, each distance tube 7 is connected with a plurality of baffle plates 8, and each distance tube 7 and each heat exchange tube 6 are arranged in a connecting hole of each baffle plate 8; the baffle plate 8 comprises an upper layer J-shaped baffle plate 801 and a lower layer J-shaped baffle plate 802 which are arranged in pair, symmetrically installed and have the same bending radian, as shown in fig. 2 and 3, the upper end of the upper layer J-shaped baffle plate 801 is tightly attached to the surface of the top end inside the cylinder 1, the lower end of the lower layer J-shaped baffle plate 802 is tightly attached to the surface of the bottom end inside the cylinder 1, and a flow channel is formed between the upper layer J-shaped baffle plate 801, the lower layer J-shaped baffle plate 802 and the cylinder 1.

The upper layer J-shaped baffle plate 801 and the lower layer J-shaped baffle plate 802 are composed of a long plate 8-1 and a short plate 8-2 which are parallel to each other and a connecting plate 8-3 which connects the long plate 8-1 and the short plate 8-2, and the connecting parts between the long plate 8-1 and the short plate 8-2 and the connecting plate 8-3 are provided with chamfers alpha of about 45 degrees. The ratio of the length h1 of the long plate 8-1 to the length h2 of the short plate 8-2 is 1.9:1, and the length h2 of the short plate 8-2 is greater than the radius of the cylinder 1. The distance w between the short plates 8-2 in the two adjacent upper J-shaped baffle plates 801 and the lower J-shaped baffle plates 802 is 0.7 times of the diameter d of the cylinder 1.

Fig. 4 is a schematic structural diagram of an i-shaped baffle plate heat exchanger and a J-shaped baffle plate heat exchanger, and the calculation accuracy is ensured by adopting unstructured grid division and performing local grid encryption.

As shown in fig. 5, for the analysis of the results, ZX direction and XY direction cross sections were selected and displayed as velocity and temperature clouds, and the cross section positions were as follows.

FIG. 6 is a cloud of velocity profiles for a drum baffle heat exchanger; FIG. 7 is a cloud of velocity profiles for a J-baffle heat exchanger. As can be seen from the comparative analysis of fig. 6 and 7, the J-shaped baffle heat exchanger has an optimized baffle plate structure, so that the internal fluid flow distribution turbulence is larger, the swirl is increased, and the convective heat transfer between the fluid and the fluid in the pipe is enhanced.

Fig. 8 is a cloud view of the speed distribution of the I-shaped baffle plate heat exchanger on the XY section, and fig. 8 is a cloud view of the speed distribution of the J-shaped baffle plate heat exchanger on the XY section. As can be seen from the comparative analysis of fig. 8 and 9, the J-shaped baffle heat exchanger has an optimized baffle structure, so that the velocity distribution of the fluid in the tube is more uniform, the maximum velocity is reduced, but the fluid mixing degree is enhanced, and the convective heat exchange between the fluid and the fluid in the tube is enhanced.

Fig. 10 is a cloud view of velocity vector distribution in 4XY cross section for a i-baffle heat exchanger, and fig. 11 is a cloud view of velocity vector distribution in 4XY cross section for a J-baffle heat exchanger, with the direction of the arrows representing the direction of fluid flow. Through comparative analysis of fig. 10 and 11, it can be known that the flow step length of the fluid in the J-shaped baffle heat exchanger is increased, and the heat exchange effect is enhanced.

Fig. 12 is a cloud temperature profile for a i-baffle heat exchanger, and fig. 13 is a cloud temperature profile for a J-baffle heat exchanger. Through comparative analysis of fig. 12 and 13, it can be known that the fluid temperature distribution in the J-shaped baffle heat exchanger is more uniform, and the heat exchange effect is enhanced.

The above embodiments are merely illustrative of the technical concepts and features of the present invention, and the purpose of the embodiments is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A J-shaped baffle plate heat exchanger comprises a cylinder body (1), a left tube box (2) and a right tube box (3) which are respectively connected to tube plates (4) on two sides of the cylinder body (1), a plurality of pull rods (5) and heat exchange tubes (6) are arranged in the cylinder body (1) in parallel, one end of each pull rod (5) is fixed to the tube plate (4) on one side, a distance tube (7) is sleeved on the outer wall of each pull rod (5), two ends of each heat exchange tube (6) are respectively fixed to the tube plates (4) on two sides, a plurality of baffle plates (8) are connected to each distance tube (7), and each distance tube (7) and each heat exchange tube (6) are arranged in a connecting hole of each baffle plate (8) in a penetrating mode; it is characterized in that the preparation method is characterized in that,

the baffle plate (8) comprises an upper layer J-shaped baffle plate (801) and a lower layer J-shaped baffle plate (802) which are arranged in pair and symmetrically installed, the upper end of the upper layer J-shaped baffle plate (801) is tightly attached to the surface of the top end inside the cylinder body (1), the lower end of the lower layer J-shaped baffle plate (802) is tightly attached to the surface of the bottom end inside the cylinder body (1), and a flow channel is formed among the upper layer J-shaped baffle plate (801), the lower layer J-shaped baffle plate (802) and the cylinder body (1).

2. The J-baffle heat exchanger as set forth in claim 1 wherein the upper J-baffle (801) and the lower J-baffle (802) are J-baffles of the same curvature; the upper layer J-shaped baffle plate (801) and the lower layer J-shaped baffle plate (802) are respectively composed of a long plate (8-1), a short plate (8-2) and a connecting plate (8-3) which connects the long plate (8-1) and the short plate (8-2) which are parallel to each other.

3. A J-baffle heat exchanger according to claim 2, wherein the junctions between the long plates (8-1) and the short plates (8-2) and the connecting plates (8-3) are each provided with a chamfer α of 40-50 °.

4. The J-baffle heat exchanger as claimed in claim 2, wherein the length ratio between the long plates (8-1) and the short plates (8-2) is 1.5-2: 1, and the length of the short plates (8-2) is greater than the radius of the cylinder (1).

5. The J-baffle heat exchanger as claimed in claim 2, wherein the distance w between the short plates (8-2) in the upper J-baffle (801) and the lower J-baffle (802) is 0.6-0.8 times the diameter d of the cylinder (1).