CN112985116A

CN112985116A - Internal spiral heat exchanger

Info

Publication number: CN112985116A
Application number: CN202110375366.7A
Authority: CN
Inventors: 余华明; 畅国帏; 李东洺
Original assignee: Shunde Polytechnic
Current assignee: Shunde Polytechnic
Priority date: 2021-04-08
Filing date: 2021-04-08
Publication date: 2021-06-18

Abstract

The invention discloses an internal spiral heat exchanger, which comprises an upper cover, a base and a middle section connected between the upper cover and the base, wherein the middle section comprises an inner pipe and an outer sleeve pipe, the upper cover and the base are provided with a bend-through opening on the surface of the upper cover plate and the surface of the base plate, annular grooves are arranged on the upper cover plate surface and the surface of the base plate around the opening of the bend-through, openings at two ends of the bend-through are connected with the inner pipe of the adjacent middle section, an interlayer is formed between the outer sleeve pipe and the inner pipe as well as the annular grooves, and communicating cavities are arranged in the upper cover and theThe upper cover and the base are formed by metal injection molding, the inner wall surface of the inner pipe is provided with first thread ribs, the thread spacing L1 of the first thread ribs meets the requirements that L1 is less than 0.028Re multiplied by D1, and the Reynolds number Re =isequal to

V is the average flow velocity of the fluid on the inner wall of the inner tube, D1 is the diameter of the inner wall of the inner tube, and mu is the current kinematic viscosity coefficient of the fluid on the inner wall of the inner tube. A circuitous heat exchange structure with a longer route is formed in the heat exchanger, and the sufficient heat exchange between the refrigerant and the secondary refrigerant can be realized.

Description

Internal spiral heat exchanger

Technical Field

The invention relates to the technical field of heat exchange equipment, in particular to an internal spiral heat exchanger.

Background

The existing heat exchanger is arranged in space in a coiled mode through a sleeve formed by an inner pipe and a main pipe, a refrigerant is arranged in a sleeve interlayer space between the inner pipe and the main pipe, the refrigerant is loaded in the inner pipe to realize heat exchange between the refrigerant and a secondary refrigerant, the wall of the inner pipe is used as an isolation material between the inner layer space of the inner pipe and the sleeve interlayer space, and metals with better heat conduction such as copper and the like are generally used as heat conduction metals. The inner pipe is coiled in parallel with the main pipe in the main pipe, and the gap between the outer wall of the inner pipe and the inner wall of the main pipe, i.e. the interlayer space, must be kept uniform, and even, in order to improve the heat transfer efficiency, turbulent flow structures can be properly added in the inner pipe space and the sleeve interlayer space. The end of the sleeve is connected with a part, the inner pipe and the main pipe need different pipeline connecting lines, and the outer wall of the inner pipe must penetrate through the space surrounded by the extension of the inner wall of the main pipe in topological sense. If the sleeve is straight, the sleeve needs to turn by 180 degrees after extending for a certain length, when turning occurs, the turning of the inner space of the inner pipe and the interlayer space of the sleeve needs to be respectively provided with joint pipeline parts to realize corresponding space turning, the structure of the joint pipeline parts needs to ensure double-path turning of the inner space of the inner pipe and the interlayer space of the sleeve, and the double-path turning causes direct difficulty in manufacturing the pipeline joint parts on a space topological structure. The joint pipeline part is relatively easy to realize on a large-scale heat exchanger, the joint pipeline part is made into two parts at the moment, the inner pipe steering pipeline part and the main pipe steering pipeline part are connected, the shape of the inner pipe steering pipeline connecting part can be a section of bend-through, and then the two inner pipes are connected at the end part of the inner pipe in the modes of welding, flange, sealing and the like; the main pipe connecting pipeline part is switched and communicated with two sections of outer pipes which are turned by 180 degrees through another pipeline which is different from the other pipeline connected with the end part of the inner pipe.

On the other hand, when fluid flows in the pipeline, a laminar flow phenomenon is easily formed on the pipe wall, namely fluid particles move in a direction parallel to the pipe all the time, the particles are not mixed with each other, and the fluid flows on the pipe wall even in the whole pipe like a layer of concentric cylinders in parallel, which is obviously not beneficial to heat exchange. In order to destroy the laminar flow phenomenon of fluid and improve the heat transfer performance of the heat exchanger, CN200810231358.X discloses a spiral fin self-supporting heat exchanger, wherein each heat exchange tube is welded with a spiral fin, the fin not only has the function of supporting the heat exchange tube, but also can disturb flow, so that the fluid is forced to flow spirally along the surface of the tube, the disturbance on the fluid is increased, the heat transfer coefficient can be improved, the fluid generally longitudinally flows on the shell side of the heat exchanger, but the pitch of the fin is larger, the spacing between the fin and the tube is equal, the fin can only be installed on the outer wall of the tube, so that the overall performance is limited by conditions, and the structure and the performance of the fin can be.

Disclosure of Invention

The invention aims to provide a heat exchanger with an internal spiral, wherein two end parts and a middle part of the heat exchanger are connected, so that a circuitous heat exchange structure with a longer route is formed in the heat exchanger, and the heat exchange between a refrigerant and a secondary refrigerant can be realized, so that the defects of the prior art are overcome.

The invention adopts the following technical scheme to realize the purpose:

the utility model provides an internal screw heat exchanger, includes upper cover, base, connects the interlude between upper cover and base, a serial communication port, the interlude includes inner tube and outer tube, set up the curved expert of opening in upper cover face, base face on upper cover, the base, it is provided with the annular to encircle the opening of curved expert on upper cover face, base face, the inner tube of adjacent interlude is connected to the both ends opening of curved expert, form the intermediate layer between outer tube and inner tube and the annular, set up the intercommunication chamber in upper cover and the base and make and be close to two adjacent intermediate layers intercommunications of curved expert, upper cover and base are by metal injection moulding, be provided with first screw thread rib on the internal wall of inner tube, the screw thread interval L1 of first screw thread rib satisfies L1 < 0.028Re D1, wherein Reynolds number Re = I

V is the average flow velocity of the fluid on the inner wall of the inner tube, D1 is the diameter of the inner wall of the inner tube, and mu is the current kinematic viscosity coefficient of the fluid on the inner wall of the inner tube.

The outer wall surface of the inner pipe is provided with second thread ribs, the thread spacing L2 of the second thread ribs meets the requirements that L2 is less than 0.028Re '× D2, and the Reynolds number Re' = is

V 'is the average flow velocity of the interlayer fluid, D2 is the diameter of the outer wall of the inner pipe, and mu' is the current kinematic viscosity coefficient of the interlayer fluid.

The inner wall surface of the outer sleeve is provided with third thread ribs, the thread pitch L3 of the third thread ribs satisfies L3 < 0.028Re '' × D3, wherein the Reynolds number Re '' =

V 'is the average flow velocity of the fluid of the interlayer, D3 is the diameter of the inner wall of the outer sleeve, and mu' is the current kinematic viscosity coefficient of the interlayer fluid.

The both ends of inner tube extend and have the water conservancy diversion portion, the water conservancy diversion portion of inner tube stretches into the curved opening portion of upper cover, base and with curved logical sealing connection.

The second and third screw ribs have a direction opposite to that of the first screw rib.

The outer sleeve, the inner pipe and the reinforcing ribs are integrally formed by metal injection, and two ends of the outer sleeve are welded with the upper cover and the base.

The upper cover is further provided with an inlet pipe, an outlet pipe, an inlet and an outlet, the inlet pipe and the outlet pipe are communicated with the inner pipe, and the inlet and the outlet are communicated with the interlayer.

Still include a plurality of erection column, erection column fastening is connected between upper cover and base.

The invention adopts the technical proposal to achieve the following beneficial effects:

1) the metal injection molding is extended from the plastic injection molding, the metal injection molding technology and the plastic injection molding technology have the advantages of one-time molding of products with complex shapes, high product size precision, no need of machining or only need of micro-machining and the like, and meanwhile, the metal injection molding technology also overcomes the defect of low product strength in the traditional plastic molding technology. Undoubtedly, the metal injection technology applied to the heat exchanger can solve the problem of short heat exchange stroke of the double-pipe heat exchanger in a simple and effective mode, so that the double-pipe heat exchange has a long enough flow, water and the refrigerant exchange heat fully, and the heat exchange efficiency is higher.

2) The thread rib structure of the invention is distributed on the inner wall and the outer wall of the inner pipe, the heat of two fluids is transferred through the inner pipe wall, and the thread rib, the inner pipe and the outer sleeve are integrally injection molded. The thread rib is formed by a spiral lift groove formed on the wall surface of the tube, the thread space and the kinematic viscosity of the refrigerant keep a certain relation, and when the thread space is less than 0.028Re multiplied by D, the laminar state liquid film formed on the wall of the heat exchanger tube by the refrigerant can be destroyed. Secondly, the thread rib structures on the inner wall surface and the outer wall surface of the inner pipe wall are in different directions, so that heat exchange in different directions can be caused in a local space, the heat exchange temperature difference is improved, and the heat exchange efficiency is improved.

3) The heat exchange tubes are provided with a plurality of heat exchange tubes, and the heat exchange tubes are sequentially communicated to form a heat exchange pipeline, so that the length and the area of the heat exchange pipeline are increased. The mounting column is arranged between the upper cover and the base of the heat exchanger, and two ends of the mounting column are fastened with the upper cover and the base through screws, so that the whole heat exchanger is firmer and more reliable.

Drawings

Fig. 1 is a schematic perspective view of an internal spiral heat exchanger according to the present invention.

Fig. 2 is a perspective view of the middle section of the internal spiral heat exchanger of the present invention.

Fig. 3 is a cross-sectional view of the base and middle section of the internal spiral heat exchanger of the present invention.

Description of reference numerals: 1. the structure comprises an upper cover, 101, a base, 11, a ring groove, 12, a bend, 13, a communication cavity, 14, a mounting column, 15, an inlet pipe, 16, an outlet pipe, 17, an inlet, 18, an outlet, 2, an inner pipe, 21, a first threaded rib, 22, a second threaded rib, 23, a flow guide part, 24, a secondary refrigerant flow channel, 3, an outer sleeve, 31, a third threaded rib, 32, a refrigerant flow channel, 4 and reinforcing ribs.

Detailed Description

The technical solution is described in detail with reference to specific embodiments below.

As shown in fig. 1-3, the present invention discloses an internal spiral heat exchanger, which comprises an upper cover 1, a base 101, and a middle section connected between the upper cover 1 and the base 101, wherein 16 middle sections are selected and vertically arranged between the upper cover 1 and the base 101 in a 4 × 4 array, and two mutually independent heat exchange flow channels, namely a refrigerant flow channel 32 and a secondary refrigerant flow channel 24, are formed between the upper cover 1, the base 2 and the middle section.

Furthermore, the middle section comprises an inner tube 2 and an outer sleeve 3, the upper cover 1 and the base 101 are provided with a bend 12 which is opened on the surface of the upper cover 1 and the surface of the base 101, the plate surface of the upper cover 1 and the surface of the base 101 are provided with annular grooves 11 around the opening part of the bend 12, two ends of the bend 13 are opened and connected with the inner tube 2 of the adjacent middle section, an interlayer is formed between the outer sleeve 3 and the inner tube 2 and the annular grooves 11, the upper cover 1 and the base 101 are provided with a communicating cavity 13 to communicate the two adjacent interlayers close to the bend 12, the upper cover 1 and the base 101 are formed by metal injection molding, it can be understood that the two ends of the bend 12 are opened and connected with the inner tube 2 of the two adjacent middle sections, the interlayers of the two adjacent middle sections are communicated through the communicating cavity 13, so that two mutually independent heat exchange flow channels are formed between the upper cover 1, the base, the inner tube 2 cooperates with the elbow 12 to form a coolant flow passage 24, and the sandwich is used for a coolant flow passage 32.

Further, it is known that, in order to make the fluid heat exchange more sufficient, the heat exchange area of the two fluids can be increased, and the heat exchange time of the two fluids can be prolonged. However, the length of the heat exchange flow channel cannot be prolonged because the traditional sleeve type heat exchanger is limited to the length of the pipe body, although the pipeline of the threaded water pipe in the outer cylinder is long enough, the flow channel of the infiltration type outer cylinder is short, and the effective heat exchange area is greatly reduced because the threaded water pipe is arranged closely, the ideal heat exchange mode is to bend the sleeve in a snake-shaped mode, so that the heat exchange area and the flow channel length can be considered, however, the two ends of the sleeve can not be bent and formed in the traditional process, but through metal injection molding, the upper cover 1 and the base 101 can be processed with two flow channels to be connected with the two flow channels in the middle section, and the heat exchanger structure manufactured by the metal injection molding process has an efficient heat exchange effect, has higher strength and improves the production efficiency.

Furthermore, the inner wall surface of the inner tube 2 is provided with first threaded ribs 21, the thread pitch and the kinematic viscosity of the heat exchange fluid are kept in a certain relationship, especially when a liquid film formed by the heat exchange fluid on the tube wall surface of the heat exchanger is very thin, and the flow state is close to a laminar flow state, the laminar flow boundary layer can generate additional thermal resistance in the heat exchange process of the refrigerant, the arrangement of the threaded ribs is beneficial to breaking the laminar flow while increasing the heat exchange area, so that the laminar flow boundary layer cannot be fully developed, in the fluid boundary layer theory, the initial section length of the laminar flow boundary layer is 0.028Re × D, and in order to break the laminar flow state, the thread pitch is less than the value of 0.028Re × D, namely the thread pitch L1 of the first threaded ribs 21 satisfies L1 < 0.028Re × D1, wherein the reynolds number Re = meets L1 <

V is the average flow velocity of the fluid on the inner wall of the inner pipe, D1 is the diameter of the inner wall of the inner pipe, and μ is the current kinematic viscosity coefficient of the fluid on the inner wall of the inner pipe, so that a laminar boundary layer cannot develop, and similarly, the second thread rib 22 is arranged on the outer wall surface of the inner pipe 2, the thread pitch L2 of the second thread rib 22 meets the condition that L2 is less than 0.028Re '× D2, wherein the Reynolds number Re' = is

And v 'is the average flow velocity of the interlayer fluid, D2 is the diameter of the outer wall of the inner pipe, and mu' is the current kinematic viscosity coefficient of the interlayer fluid, similarly, the inner wall surface of the outer sleeve 3 is provided with third threaded ribs 31, the thread pitch L3 of the third threaded ribs 31 meets the requirement that L3 is less than 0.028Re '' × D3, wherein the Reynolds number Re '' =

Further, be connected with a plurality of strengthening rib 4 between outer tube 3 and the inner tube 2, leave the runner clearance between the adjacent strengthening rib 4, strengthening rib 4 is used for strengthening the joint strength between outer tube 3 and the inner tube 2, outer tube 3, inner tube 2 and strengthening rib 4 are by metal injection integrated into one piece, make the intensity of interlude higher, and the runner structure who makes by metal injection molding has higher heat exchange efficiency, the both ends outer wall of the outer tube 3 of interlude is sealed fixedly with upper cover 1 and base 101 through welded connection, form inseparable welded connection structure with inner tube 2 and the stainless steel outer tube 3 of copper with stainless steel upper cover 1 and base 101 with this.

Furthermore, the upper cover 1 is also provided with an inlet pipe 15, an outlet pipe 16, an inlet 17 and an outlet 18, the inlet pipe 15 and the outlet pipe 16 are communicated with the inner pipe 2, the inlet 17 and the outlet 18 are communicated with the interlayer, the coolant and the refrigerant respectively enter the inner pipe 2 of the middle section and the interlayer between the inner pipe 2 and the outer sleeve 3 from the inlet pipe 15 and the inlet 17 of the upper cover 1, namely, the two fluids respectively enter two heat exchange flow channels, the heat of the two fluids is exchanged at the middle section part through the copper inner pipe 2, the two fluids pass through the elbow 12 on the base 101 from the middle section, the secondary refrigerant enters the adjacent inner pipe 2 through the elbow 12 on the base 101, the refrigerant enters the interlayer of the adjacent middle section through the communicating cavity 13 on the base 101 and flows to the upper cover 1 along with the inner area of the middle section, so moving, the two fluids exchange heat during the movement, and finally, the coolant exits the heat exchanger at outlet tube 16 and the refrigerant exits the heat exchanger at outlet 18.

Further, still include a plurality of erection column 14, erection column 14 fastening is connected between upper cover 1 and base 101, corresponds erection column 14 and is provided with the mounting hole on upper cover 1 and the base 101, and erection column 14 passes through the screw and fastens with upper cover 1 and base 101 to make the assembly of interlude and upper cover 1 and base 101 more firm.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the inventive concept of the present invention, and these changes and modifications are all within the scope of the present invention.

Claims

1. The utility model provides an internal screw heat exchanger, includes upper cover, base, connects the interlude between upper cover and base, a serial communication port, the interlude includes inner tube and outer tube, set up the curved expert of opening in upper cover face, base face on upper cover, the base, it is provided with the annular to encircle the opening of curved expert on upper cover face, base face, the inner tube of adjacent interlude is connected to the both ends opening of curved expert, form the intermediate layer between outer tube and inner tube and the annular, set up the intercommunication chamber in upper cover and the base and make and be close to two adjacent intermediate layers intercommunications of curved expert, upper cover and base are by metal injection moulding, be provided with first screw thread rib on the internal wall of inner tube, the screw thread interval L1 of first screw thread rib satisfies L1 < 0.028Re D1, wherein Reynolds number Re = I

2. The internal spiral heat exchanger according to claim 1, wherein the outer wall surface of the inner tube is provided with second spiral ribs having a pitch L2 of L2 < 0.028Re '× D2, where reynolds number Re' = is

3. The internal spiral heat exchanger according to claim 2, wherein the inner wall surface of the outer sleeve is provided with third screw ribs having a pitch L3 of L3 < 0.028Re "x D3, which isMedium Reynolds number Re' =

4. An internal spiral heat exchanger according to any one of claims 1 to 3 wherein flow guide portions extend from both ends of the inner tube, and the flow guide portions of the inner tube extend into the elbow openings of the upper cover and the base and are sealingly connected to the elbow.

5. An internal spiral heat exchanger according to claim 4, wherein the direction of the second and third ribs is opposite to the direction of the first rib.

6. The internal spiral heat exchanger according to claim 5 wherein a plurality of ribs are connected between the outer sleeve and the inner tube, the outer sleeve, the inner tube and the ribs are integrally formed by metal injection, and both ends of the outer sleeve are welded to the upper cover and the base.

7. The internal spiral heat exchanger of claim 6 further comprising an inlet tube, an outlet tube, an inlet and an outlet disposed in the top cover, the inlet and outlet tubes communicating with the inner tube, the inlet and outlet communicating with the intermediate layer.

8. The internal spiral heat exchanger of claim 7, further comprising a plurality of mounting posts, the mounting posts being fixedly secured between the upper cover and the base.