CN105135933A - Shuttle-shaped heat transfer enhancement rotor in heat exchange tube - Google Patents

Abstract

The invention relates to a shuttle-shaped rotor for enhanced heat exchange in a heat-exchange tube. The main components include a hollow shaft and a helical blade; the rotor is a shuttle-shaped structure viewed from the axial direction of the heat-exchange tube. The hollow shaft is composed of two sections, and the hollow shaft is provided with There are two or more helical blades, and the helical blades are equally divided along the circumference of the hollow shaft; the surface of the helical blades is smooth, the helical blades intersect with the outer surface of the hollow shaft, and the outer diameter of the helical blades is slightly smaller than the inner diameter of the heat exchange tube; The thickness is kept constant, and the width is in a gradual shape. The width is the largest when it is close to the hollow shaft, and then gradually decreases; the space occupied by the rotor in the heat exchange tube of the present invention is small, the flow resistance is small, and the structure is simple. The fluid in the heat exchange tube is perpendicular to the spiral blade The radial force makes the rotor rotate around the hollow shaft, which enhances the turbulence of the fluid, destroys the flow state of the fluid near the wall, reduces the thickness of the boundary layer, and slightly scrapes the tube wall to achieve enhanced heat transfer. And the purpose of anti-scaling and descaling.

Description

Enhanced heat transfer shuttle rotor in heat transfer tube

technical field

The invention relates to an interpolation element for enhancing heat transfer and anti-scaling and descaling in heat exchange tubes used in shell-and-tube heat exchangers, heat exchange reactors and other equipment, in particular to an intercalation element using the heat transfer fluid inside the heat exchange tube as the Power, self-cleaning and enhanced heat transfer function of the shuttle rotor.

Background technique

As an important lifeblood of my country's national economic development, energy has the problems of tight supply and low utilization efficiency. Therefore, energy conservation and emission reduction are crucial to the sustainable development of my country's economy. Shell-and-tube heat exchangers are widely used in thermal power, nuclear power, petroleum, chemical industry, metallurgy, food, light industry, ship power, aerospace and other fields. The problem caused the heat exchange efficiency in the tube to be greatly reduced, and the heat transfer performance was reduced. At the same time, the fluid delivery resistance increased, and even the tube was severely blocked and could not be used. The traditional solution is to stop production for cleaning, which not only delays the production progress of the factory, but also requires paying expensive cleaning fees. Therefore, people have been studying the methods and devices of non-stop online automatic heat transfer enhancement and descaling and anti-scaling. The biggest advantage is that it is not only suitable for the manufacture of new heat exchangers, but also suitable for the transformation of old heat exchangers. Easy to manufacture.

In recent years, there have been many methods and devices for strengthening heat exchange and anti-scaling and descaling. The Chinese patent application number is ZL95236063.2, which discloses an invention titled "cleaning device for descaling and anti-scaling in heat transfer tubes". The Chinese patent application The number is CN1424554, which discloses an invention titled "Flow Disturbance Spiral Enhanced Heat Exchange and Automatic Descaling Device". These devices mainly include spiral ties and fixing frames. The flow drives the spiral link to rotate. These devices play a certain role in strengthening heat exchange and anti-scaling and descaling, but at the same time there are the following shortcomings: (1) the bond is a whole, directly scratching the heat transfer tube and damaging the inner wall of the heat transfer tube; (2) the fluid Promoting the link to rotate during flow requires a larger driving torque and consumes more fluid kinetic energy; (3) The service life of the bearing used for single-end fixing is short. The Chinese patent number is ZL200520127121.9, which discloses a patent application named "rotor type self-cleaning enhanced heat transfer device". This device is composed of a fixed frame, a rotor, a flexible shaft and a support tube. The two ends of the heat pipe; the outer surface of the rotor has helical ribs, and the rotor has a central hole; the supporting frame is arranged between the rotor and the fixed frame, and the flexible shaft passes through the central hole of the rotor and the supporting tube and is fixed on the two fixed frames. Under the action of the fluid in the tube, the rotor rotates around the flexible shaft, and the rotor blades slightly scrape the tube wall to prevent and remove scale. In addition, the rotation of the rotor disturbs the fluid in the tube to enhance the degree of fluid turbulence, thereby playing a role Strengthen the role of heat exchange. The disturbance of the fluid by the above-mentioned rotor is limited, and the rotation speed of the rotor is determined by the helix angle of the flight. When the flight lead is small, the rotation speed of the rotor is fast, and the resistance to the fluid increases accordingly. In order to solve this problem, Chinese patent application number 200910077378.0, the title of the invention is "a unit combined heat transfer enhancement device", which is composed of a rotor, a support frame, a sleeve shaft and a connecting axis, and the support frame is fixed at both ends of the heat transfer tube The two ends of the connecting axis are respectively fixed on the support frame, and multiple rotors are mounted on the connecting axis. The rotor is composed of spoiler blades, hinge structure, and tail screw drive blades. This structure can significantly reduce the fluid in the pipe. flow resistance, reduce wear, and prolong the service life of the rotor, but the rotor with this structure cannot better inhibit fouling, and the heat transfer efficiency and online cleaning effect are not optimal.

Contents of the invention

The purpose of the present invention is to design a rotor with a new structure. The rotor has a shuttle-shaped structure viewed from the axial direction of the heat exchange tube. The blades of the rotor present a spiral gradual change shape, and the overall surface area is small, which can greatly reduce the flow resistance of the medium in the tube. It saves production cost and is easy to install, and has dual functions of automatic online anti-scaling and descaling and enhanced heat transfer.

In order to achieve the above object, the technical solution proposed by the present invention is: a shuttle-shaped rotor for enhanced heat exchange in the heat exchange tube, which is characterized in that: the main components include a hollow shaft and a helical blade; the rotor is a shuttle-shaped structure viewed from the axial direction of the heat exchange tube, The hollow shaft is composed of two sections, the hollow shaft is provided with two or more helical blades, and the helical blades are equally divided along the circumference of the hollow shaft; the surface of the helical blades is smooth, and the helical blades intersect with the outer surface of the hollow shaft. The outer diameter of the helical blade is slightly smaller than the inner diameter of the heat exchange tube; the thickness of the helical blade is kept constant, and the width is gradually changing, and the width is the largest when it is close to the hollow shaft, and then gradually decreases; The resistance is small and the structure is simple. The force of the fluid in the heat exchange tube perpendicular to the radial direction of the spiral blade makes the rotor rotate around the hollow shaft, which enhances the turbulence of the fluid, destroys the flow state of the fluid near the wall, and reduces the thickness of the boundary layer. And it has a slight scraping effect on the tube wall to achieve the purpose of enhancing heat transfer and anti-scaling and descaling.

The heat exchange enhanced shuttle rotor in the heat exchange tube of the present invention is characterized in that the helical blade and the hollow shaft are made of polymer materials, polymer matrix composite materials, metal or ceramic materials.

The enhanced heat exchange shuttle rotor in the heat exchange tube of the present invention is characterized in that the two ends of the hollow shaft have a coaxial structure, and the head of the hollow shaft of each rotor is centered and matched with the tail of the hollow shaft of the previous rotor. , the coaxial structure can be socket ball, universal joint or buckle.

The heat exchange enhanced heat exchange shuttle rotor in the heat exchange tube of the present invention is characterized in that the projection of the helical blade on the axial section is an elliptical arc or a circular arc curve, and the root of the helical blade intersects with the outer surface of the hollow shaft.

The enhanced heat exchange shuttle-shaped rotor in the heat exchange tube of the present invention can be connected end-to-end in a whole string and installed on the connection axis. The connection axis can be a rigid round rod or a flexible soft rope, or can be divided into Several groups with the same or different numbers of rotors make the rotors rotate evenly.

The beneficial effects of the present invention are: 1. The overall surface area of the invented rotor is small, the space occupied in the heat exchange tube is small, the production cost is saved and it is convenient for installation, the flow resistance is small, and it is more conducive to anti-fouling and descaling and enhanced transmission. 2. The rotor rotates under the action of the fluid in the heat exchange tube, and the fluid forms a three-dimensional spiral flow state, which enhances the degree of turbulence of the fluid and is more conducive to enhancing heat transfer; 3. The spiral blades of the rotor are in the heat exchange tube during rotation The wall plays a slight scraping effect, which reduces the thickness of the fluid boundary layer, destroys the flow state of the fluid at the tube wall, removes the dirt on the inner wall of the heat exchange tube, and reduces the deposition of dirt on the inner wall of the heat exchange tube, which is beneficial Extend the service life of the whole device and reduce the frequency of cleaning.

The enhanced heat exchange shuttle-shaped rotor in the heat exchange tube involved in the present invention, the parameters such as the length of the single rotor, the diameter of the outer circle of rotation, and the angle at which the helical blades are inclined can be determined according to the working conditions such as the inner diameter of the heat transfer tube, the flow rate of the medium in the tube, and the manufacturing cost. Depending on the situation, the adjacent rotors can be connected in a synchronous rotation mode, or in a structure of independent rotation.

Description of drawings

Fig. 1 is a schematic diagram of the structure of a shuttle-shaped rotor for enhancing heat exchange in a heat exchange tube of the present invention.

Fig. 2 is a top view of Fig. 1 .

Fig. 3 is a three-dimensional schematic diagram of the structure of the shuttle-shaped rotor for enhanced heat exchange in the heat exchange tube of the present invention.

Fig. 4 is a schematic diagram of the installation structure of a shuttle-shaped rotor for enhanced heat exchange in the heat exchange tube of the present invention.

In the figure, 1-hollow shaft, 2-helical blade, 3-heat exchange tube, 4-support frame, 5-connection axis, 6-boss, 7-groove, 8-limiting piece.

Detailed ways

An implementation method of the enhanced heat transfer shuttle-shaped rotor in the heat exchange tube of the present invention, as shown in Figure 4, the enhanced heat transfer device includes a shuttle-shaped rotor, a limiting member 8, a heat exchange tube 3, a support frame 4 and a connecting axis 5. The connection axis 5 connects several rotors in series, and the multiple rotors can be divided into several groups of rotor strings by the limiter 8. The support frame 4 is fixed on both ends of the heat exchange tube 3, and the two ends of the connection axis 5 are respectively fixed on the support frame. 4, the rotor of the present invention consists of several helical blades 2 fixed on the surface of the hollow shaft 1. Among the two adjacent rotors, the boss 6 at the head of the hollow shaft 1 of one rotor is combined with the groove 7 at the tail of the hollow shaft 1 of the other rotor, so as to connect and adjust them to be coaxial. The coaxial structure It can be a ball socket, universal joint and buckle structure, and it can also be a simple planar structure for occasions where the coaxiality of the rotor is not high.

The enhanced heat exchange shuttle rotor in the heat exchange tube of the present invention, as shown in Figure 1 to Figure 3, the cross-sectional shape of the hollow shaft 1 of the rotor is a hollow cylinder; Figure 1 is a schematic diagram of the structure of the enhanced heat exchange shuttle rotor in the heat exchange tube of the present invention, There are two helical blades 2 on the hollow shaft 1, and the two helical blades 2 are equally divided and arranged on the surface of the hollow shaft 1; It is the largest when it is close to the hollow shaft 1, and then gradually decreases; FIG. 3 is a three-dimensional schematic diagram of a shuttle-shaped rotor for enhanced heat exchange in the heat exchange tube of the present invention.

In the present invention, the fluid in the heat exchange tube 3 generates axial force and rotational moment on the rotor during the flow process, thereby pushing the rotor to rotate, and the fluid forms a three-dimensional spiral flow state, which intensifies the turbulent flow intensity of the fluid and destroys the turbulence close to the tube wall. The flow state of the fluid reduces the thickness of the boundary layer and slightly scrapes the tube wall, thereby achieving the purpose of enhancing heat transfer and preventing and removing scale. Furthermore, material and machining costs can be saved by eliminating the hollow shaft section between the screw blades 2 or by reducing the diameter of the hollow shaft end.

Claims (4)

1. The enhanced heat transfer shuttle rotor in the heat transfer tube is characterized in that: the main components include a hollow shaft and a helical blade; the rotor is a shuttle-shaped structure viewed from the axial direction of the heat transfer tube, and the hollow shaft is composed of two sections, the hollow Two or more helical blades are arranged on the shaft, and the helical blades are equally divided along the circumference of the hollow shaft; the surface of the helical blades is smooth, the helical blades intersect with the outer surface of the hollow shaft, and the outer diameter of the helical blades is slightly smaller than the inner diameter of the heat exchange tube; The thickness of the helical blade remains constant, and the width is in a gradual shape, and the width is the largest when it is close to the hollow shaft, and then gradually decreases. 2. The shuttle-shaped rotor for enhanced heat exchange in heat exchange tubes according to claim 1, characterized in that, the helical blades and the hollow shaft are made of polymer materials, polymer-based composite materials, metal or ceramic materials . 3. The shuttle-shaped rotor for enhanced heat exchange in heat exchange tubes according to claim 1, characterized in that the two ends of the hollow shaft have coaxial structures, the head of the hollow shaft of each rotor and the tail of the hollow shaft of the previous rotor Centered and mated, coaxial structures can be socket balls, universal joints or snap fits. 4. The shuttle-shaped rotor for enhanced heat exchange in heat exchange tubes according to claim 1, characterized in that the projection of the helical blades on the axial section of the heat exchange tubes is an elliptical arc or a circular arc curve, and the root of the helical blades is in contact with the outer surface of the hollow shaft. intersect.