CN110314973B - Die for preparing heat exchanger pipe fitting - Google Patents

Abstract

The invention relates to a die for preparing a heat exchanger pipe fitting, and belongs to the technical field of heat exchanger pipe fitting manufacturing. The device comprises an inner die, an outer die and a supporting die of the outer die; a forming groove corresponding to the fixing structure on the heat exchanger pipe fitting is formed in the inner wall of the outer die; the inner mold comprises a core mold, a closing mold and a sealing mold; the closed mould forms the main body part of the inner mould and is used for installing and fixing the core mould; the core module, the closing module and the sealing module form an expansion space, and the sealing module is lined on the inner wall of the workpiece; the core body die is provided with a flow passage communicated with the expansion space; the expansion space corresponds to the molding groove of the outer mold. The invention skillfully manufactures the convex fixing structure on the side wall of the pipe fitting, so that the pipe fitting can form stable combination when being installed, namely, a certain gap is always kept between the pipe fittings and the pipe fitting is not impacted by vibration; thereby improving the stability and the using effect of the product.

Description

Die for preparing heat exchanger pipe fitting

Technical Field

The invention relates to a die for preparing a heat exchanger pipe fitting, and belongs to the technical field of heat exchanger pipe fitting manufacturing.

Background

The heat exchanger is also called a heat exchanger, and is special equipment for exchanging heat of two fluids. Has important application in the industrial production of petroleum, chemical industry, light industry, pharmacy, energy and the like. For example, the heat exchanger can be used as a heater, a cooler, a condenser, an evaporator, a reboiler and the like in chemical production; the coal-fired power plant adopts a polytetrafluoroethylene heat exchanger for waste heat recovery in order to reduce the temperature of discharged smoke. The fluoroplastic heat exchanger is adopted, so that the acidic corrosion of the flue gas can be prevented. The expansion-limiting pressure-applying heating welding process for pipe plate in fluoroplastic heat exchanger is one key technology for connecting pipe fitting and pipe plate.

In the prior art, common heat exchangers are classified into plate type, shell-and-tube type and coaxial type. The above heat exchangers each have advantages and disadvantages.

The plate heat exchanger is made up by using thin metal plate to press into corrugated heat-exchanging plate, then stacking them, fastening them by using clamping plate and bolt. But the separation of the two fluids is mainly dependent on sealing strips and fastening force, so that the operating pressure cannot exceed 2.5 MPa; poor resistance to pressure shocks and pressure shocks; the fluid passing through the plate heat exchanger has a large pressure drop and also has the potential for leakage when the pressure is high.

The coaxial heat exchanger consists of an inner pipe and an outer sleeve which are concentric, and cold and hot fluids flow in annular gaps of the inner pipe and the outer sleeve respectively and transfer heat simultaneously. Therefore, the shell is not needed, and only the outer sleeve needs to be insulated and protected mechanically. The common form is that the outer sleeve is wrapped with a layer of heat preservation material and then wrapped with a layer of polymer material. Because the pipe fitting is not provided with the shell, the pipe fitting can be bent, twisted and wound into various shapes, and can meet the requirements of different places so as to be placed in various strange spaces. It is usually made into a spiral shape. In practice, a coaxial heat exchanger can also be considered as a special type of shell-and-tube heat exchanger, as well as a special form of shell-and-tube heat exchanger in which the shell is deformed into an outer jacket. It is better in heat exchange efficiency, but is more complicated in manufacture compared with a shell-and-tube type, has smaller heat exchange area under unit mass, and has poorer pressure shock and pressure impact resistance.

A shell-and-tube heat exchanger, which is a type of heat exchanger with a tube side and a shell side; one fluid is in the tube side and the other fluid is in the shell side. The heat exchange tube can be made into various structures, such as in-line, U-shaped, S-shaped, M-shaped, coil-shaped, spiral and the like. It can also be made into the form of cyclone tube. The heat exchange efficiency of the shell-and-tube heat exchanger is lower than that of a plate heat exchanger, but the operation is safer and more stable, and the operation pressure can be higher. But it is usually necessary to fix the heat exchange tube members by tube plates. The in-line heat exchange tube is convenient to install the tube plate, the tube plate is difficult to install by other structures, a specially-made fixing structure is usually needed, and the fixing effect is general, so that the capability of resisting pressure vibration and pressure impact is poor. Although the in-line type has good capability of resisting pressure vibration and pressure impact after being fixed by the tube plate, the tube plate plays a role in blocking flow to liquid in a shell pass to a certain extent, so that the flow velocity of the inner fluid and the flow velocity of the outer fluid have large velocity difference, and the heat exchange efficiency is greatly influenced.

Disclosure of Invention

The invention aims to solve the problems, and provides a die for preparing a heat exchanger pipe fitting. The pipe fitting manufactured by the die is suitable for a shell-and-tube heat exchanger or a coaxial heat exchanger. The pipe fitting is used for a shell-and-tube heat exchanger, so that the shell-and-tube heat exchanger can have good capability of resisting pressure vibration and pressure impact without a pipe plate; the pipe fitting is used for the coaxial heat exchanger, so that good stability is generated between coaxial pipes of the coaxial heat exchanger, and the defect of poor vibration resistance between the coaxial pipes in the prior art is overcome.

The technical scheme for solving the problems is as follows:

the mould for preparing the heat exchanger pipe fitting comprises an inner mould, an outer mould and a supporting mould of the outer mould; a forming groove corresponding to the fixing structure on the heat exchanger pipe fitting is formed in the inner wall of the outer die; the inner mold comprises a core mold, a closing mold and a sealing mold; the closed mould forms the main body part of the inner mould and is used for installing and fixing the core mould; the core module, the closing module and the sealing module form an expansion space, and the sealing module is lined on the inner wall of the workpiece; the core body die is provided with a flow passage communicated with the expansion space; the expansion space corresponds to the molding groove of the outer mold.

In the above technical solution of the present invention, the sealing module is a component of the inner mold, and has fixing and protecting functions on the core module, and forms an expansion space together with the core module and the sealing module. The sealing module is a film-shaped object made of flexible material, mainly used for sealing and needs an object for bearing or lining the object when in use. In the present invention, it is the inner wall of the workpiece that functions as a spacer.

Preferably, the core module comprises a core body and a delivery pipe with the flow channel inside, wherein the core body is provided with a radial connecting channel, and the flow channel is communicated with the expansion space through the radial connecting channel.

Preferably, in the above technical solution, the outer wall of the core body is a cylindrical wall.

Preferably, the outer die comprises an outer die inner wall and an outer die outer wall; the inner wall of the outer mold is provided with the forming groove; the outer wall of the outer die comprises a first slope wall, a second slope wall and a top wall which are radially and symmetrically arranged; the supporting molds are in one group, each group comprises two supporting molds, and the two supporting molds in the same group are symmetrically arranged; the inner wall of each support mould has a shape matching the broken surface wall so that the outer mould is stabilised by applying a force against the two support moulds of the same set in the proximity of each other.

In the above technical scheme of the invention, the pipe fitting is a pipe fitting with a fixed structure.

The pipe fitting has the following specific structure:

the cross section of the pipe fitting is of a regular X-shaped structure, so that the pipe fitting is provided with X side walls; the side wall is a male side wall, or comprises a male side wall and a female side wall; x is a positive integer and is more than or equal to 4;

when the male sidewall and the female sidewall are included, the male sidewall is uniformly arranged in the entire circumferential direction;

the female sidewall is formed by a sidewall body;

the male side wall is composed of a side wall body and a fixing structure;

the fixing structure is a structure formed by the outward protrusion of the side wall body and is integrally connected with the side wall body.

The fixing structure comprises a supporting wall connected with the side wall body and a fixing wall which is not directly contacted with the side wall body; the supporting wall is connected with the fixed wall directly or through a transition wall.

The supporting wall is of a slope-shaped structure, and the fixing wall is of a flat-top-shaped structure.

The slope of the supporting wall is 15-60 degrees.

The side wall of the pipe fitting is provided with a convex fixing structure. Therefore, when two identical pipe members are assembled to each other in close contact, a gap is generated between the pipe members due to the steric hindrance of the fixing structure. A set of fixing structures is arranged on each unit length of pipe fitting, so that the gap between long pipe fittings is stable. Due to the fixed structure, a tube plate is not needed to keep proper distance between the tube pieces, and the capacity of the shell side can be ensured. And to the installation of pipe fitting, only need to cramp a set of structure of a plurality of pipe fittings, this group of structure just can form stable structure, then installs in the tube shell, just can form scientific and reasonable's shell and tube heat exchanger's heat transfer foundation structure.

When the pipe fitting is applied to a coaxial pipe, a reasonable matching caliber needs to be set for the inner pipe and the outer pipe. The outer tube typically has an inner diameter slightly larger than the outer diameter of the inner tube, which facilitates installation. After the installation is finished, the installation can be directly used. The configuration that the inner diameter of the outer pipe is slightly larger than the outer diameter of the inner pipe does not need to worry about shaking, because the product is usually suitable for high-temperature environment, the inner pipe is communicated with a heating medium, and the outer pipe is communicated with a cooling medium; the inner tube will expand to a certain extent and fill up a slightly larger dimension to form a stable structure.

In conclusion, the invention has the following beneficial effects:

the invention skillfully manufactures the convex fixing structure on the side wall of the pipe fitting, so that the pipe fitting can form stable combination when being installed, namely, a certain gap is always kept between the pipe fittings and the pipe fitting is not impacted by vibration; thereby improving the stability and the using effect of the product.

Drawings

FIG. 1 is a side view of a first embodiment of the present invention;

FIG. 2 is a cross-sectional view along AA of FIG. 1;

FIG. 3 is an enlarged view of a portion of the area A of FIG. 2;

FIG. 4 is an assembled cross-sectional view of the pipe and the outer mold;

figure 5 is a front view of the inner mold;

figure 6 is a side semi-sectional view of the inner mold;

FIG. 7 is a side cross-sectional view of the outer mold;

FIG. 8 is a schematic structural diagram of a second embodiment of the present invention;

fig. 9 is an assembly view of the first embodiment of the present invention.

In the figure, the W-side wall, Wx-male side wall, Wy-female side wall, 10-side wall body, 20-fixed structure, 20 a-fixed wall, 20 b-transition wall, 20 c-support wall, alpha-slope;

100-gap; 200-an inner tube;

310-inner mold, 311-core module, 311-1-core body, 311-2-runner, 312-closed module, 313-sealed module, 314-expansion space;

320-outer mold, 320-1-forming groove, 321-outer mold inner wall, 322-outer mold outer wall, 323-1 first slope wall, 323-2-top wall, 323-3-second slope wall;

330-supporting the mould.

Detailed Description

The invention is further explained below with reference to the drawings.

The present embodiments are to be considered in all respects as illustrative and not restrictive. Any changes that may be made by one skilled in the art after reading the description of the invention herein will be covered by the patent laws within the scope of the appended claims.

Example one

The pipe fitting of the heat exchanger is suitable for a coaxial heat exchanger and a shell-and-tube heat exchanger. As shown in fig. 1-2, the cross-section of the tube is a regular octagonal structure, so that the tube has 8 sidewalls W. These sidewalls W are all male sidewalls Wx. The male sidewall Wx is constituted by the sidewall body 10 and the fixing structure 20. The fixing structure 20 is a structure formed by protruding the sidewall body 10, and is integrally connected with the sidewall body 10.

Fig. 3 is a partially enlarged view of fig. 2, which clearly shows a specific shape of the fixing structure 20. It includes a supporting wall 20c connected with the sidewall body 10, a fixing wall 20a not directly contacted with the sidewall body 10; the support wall 20c is connected to the fixed wall 20a via a transition wall 20 b. The supporting wall 20c is a slope-shaped structure, and the fixing wall 20a is a flat-top-shaped structure. The slope α of the support wall 20c may be 15 to 60 °, and in the present embodiment, α is 23.6 °. The support wall is so called because it enables two tubes adjacent to each other to be supported by each other and maintain a stable gap 100 between the tubes after being mounted to the heat exchanger, as shown in fig. 9.

The following is a detailed description of the method of making the tube of the present example.

The manufacturing method is expansion forming, the equipment required by the expansion forming is a hydraulic press, and a die matched with the hydraulic press is also required. The mold comprises an inner mold, an outer mold and a supporting mold.

Specifically, as shown in fig. 4, this figure shows the installed relationship of the pipe with the outer mold 320 and the support mold 330. The inner mold is sleeved inside the pipe fitting, and the pipe fitting is not cut open, so the inner mold cannot be shown in the figure.

As shown in fig. 5, this figure shows the fitting relationship of the pipe with the inner mold 310.

Thus, with reference to fig. 4 and 5, the installation relationship between the pipe and the mold can be clearly understood.

Fig. 6 is a side half sectional view of the inner mold 310. In the figure, 311-core module, 311-1-core body, 311-2-flow channel, 312-closing module, 313-sealing module, 314-expansion space. After understanding the fitting relationship between the pipe and the mold and the composition of the inner mold 310, the principle of forming the fixed structure 20 is analyzed. First, hydraulic oil in a high pressure state is supplied from a hydraulic machine, and flows into the expansion space 314 formed by the core module 311, the closing module 312, and the sealing module 313 through the flow passage 311-2. The core module 311 and the closing module 312 are both made of a hard material, and can perform a pressure maintaining function without being expanded due to an increase in oil pressure. The sealing module 313 is a polymer film made of flexible material and having good elasticity; that is to say the sealing module 313 can be flared outwards; it will be appreciated that the expansion space 314 is an annular space and thus the direction of flaring is circumferential rather than in a certain direction. Referring to fig. 4 and 5, it can be seen that the periphery of the expansion space 314 is a pipe, and the periphery of the pipe is an outer mold 320, which are tightly attached to each other. In fig. 7, if the inner wall of the outer mold 320 has no molding groove 320-1, the fixing structure 20 cannot be expanded. Fortunately, the molding groove 320-1 is present, that is, the fixing structure 20 is molded by the molding groove 320-1. And it can be known that the distribution of the fixing structures 20 on the sidewall of the pipe is synchronized with the distribution of the molding groove 320-1 on the inner wall of the outer mold 320. Since fig. 2 discloses the distribution of the fixing structures 20, the distribution of the molding grooves 320-1 on the inner wall of the outer mold 320 does not need to be described separately.

After understanding the forming principle, the operation becomes very simple. Firstly, assembling a pipe fitting and a die; then the flow passage of the hydraulic machine and the inner die are communicated. And starting the hydraulic machine to a preset pressure value, opening an oil way switch, maintaining the pressure for 30S, then releasing the pressure, and finally taking out the formed pipe fitting.

Example two

The pipe fitting of the heat exchanger is suitable for a coaxial heat exchanger and a shell-and-tube heat exchanger. As shown in fig. 1-2, the cross-section of the tube is a regular octagonal structure, so that the tube has 8 sidewalls W. These sidewalls W include a male sidewall Wx and a female sidewall Wy, the male sidewall Wx being uniformly arranged in the entire circumferential direction; in this embodiment, the male sidewall Wx and the female sidewall Wy are spaced apart. The female sidewall Wy is constituted by a sidewall body 10; the male sidewall Wx is composed of a sidewall body 10 and a fixing structure 20; the fixing structure 20 is a structure formed by protruding the sidewall body 10, and is integrally connected with the sidewall body 10.

Except for the above differences, the other structures of the present embodiment are the same as those of the second embodiment. And the mold and the manufacturing method are also almost the same. The dies are slightly different, but the distribution of the forming grooves of the outer dies is synchronized with the distribution of the fixing structure of the pipe needed.

Claims (2)

1. The mould for preparing the heat exchanger pipe fitting comprises an inner mould (310), an outer mould (320) and a supporting mould (330) of the outer mould; the method is characterized in that: a molding groove (320-1) is formed in the inner wall of the outer die (320); the inner mold (310) comprises a core mold (311), a closing mold (312) and a sealing mold (313); a closing mold (312) constituting a main body portion of the inner mold (310) and for mounting and fixing the core mold (311); the core module (311), the closing module (312) and the sealing module (313) form an expansion space (314), and the sealing module (313) is lined on the inner wall of the workpiece; the core module (311) is provided with a flow passage communicated with the expansion space (314); the expansion space (314) corresponds to a molding groove (320-1) of the outer die (320);

the sealing module (313) is a film-shaped object made of flexible materials;

the core module (311) comprises a core body (311-1) and a delivery pipe (311-2) with the flow channel inside, the core body (311-1) is provided with a radial connecting channel, and the flow channel is communicated with the expansion space (314) through the radial connecting channel;

the outer mold (320) comprises an outer mold inner wall (321) and an outer mold outer wall (322); the inner wall (321) of the outer die is provided with the molding groove (320-1); the outer die wall (322) comprises a first slope wall, a second slope wall (323-1, 323-3) and a top surface wall (323-2), which are radially and symmetrically arranged;

the number of the support molds (330) is two, and the two support molds (330) are symmetrically arranged; the inner wall of each support die has a shape matching the first and second sloped walls (323-1, 323-3) so that the outer die (320) is stabilized by applying a force to the two support dies (330) that approach each other;

the heat exchanger pipe fitting has the following specific structure:

the cross section of the heat exchanger pipe fitting is of a regular X-edge structure, so that the heat exchanger pipe fitting is provided with X side walls; the side wall is a male side wall, or comprises a male side wall and a female side wall; x is a positive integer and is more than or equal to 4;

when the male sidewall and the female sidewall are included, the male sidewall is uniformly arranged in the entire circumferential direction;

the female sidewall is formed by a sidewall body;

the male side wall is composed of a side wall body and a fixing structure;

the fixing structure is a structure formed by the outward protrusion of the side wall body and is integrally connected with the side wall body.

2. The mold of claim 1, wherein: the outer wall of the core body (311-1) is a cylindrical wall.

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