Flange-connected dual-circuit topology isolated rotary tube heat exchanger

Abstract

The present invention discloses a flange-connected dual-path topology isolation rotary tube heat exchanger, which includes at least two end covers, the end covers include an end cover body, a flange, and a plurality of U-tube cavities arranged in a directional and orderly manner, the U-tube cavity includes a bend and a straight tube cavity, a sleeve cavity is arranged around the straight tube cavity, and the two straight tube cavities of the U-tube cavity are connected through the bend, the end cover body is provided with a connecting cavity at the inner side of the U-tube cavity bend, and the connecting cavity connects the two sleeve tube cavities of the U-tube cavity at the inner side of the bend, and the flange is provided with a through channel adapted to the straight tube cavity and the sleeve cavity, so that after the flanges of the two end covers are sealed and spliced, an S-shaped coolant flow channel is formed in the two end covers by the bend and the straight tube cavity, and a unique circuitous refrigerant flow channel is formed by the connecting cavity; the end covers are formed by metal injection molding. The heat exchanger of the present invention uses metal injection molding technology to solve the integral molding of the bend and sleeve in a simple and effective way, with excellent heat exchange effect and mass production.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchange equipment, and more specifically to a flange-connected dual-path topology isolation rotary tube heat exchanger. Background Art

[0002] The heat exchanger of the existing heat pump water heater and air conditioner mainly includes a shell, an inner tube and a coil. The refrigerant inlet is arranged on the side wall of the shell. After the high-speed refrigerant enters the inner cavity of the shell from the side wall of the shell, it exchanges heat with the water in the coil. For example, the Chinese invention application with application number CN200810069750.9 and the name of a heat exchanger includes a shell, an inner tube and a coil. The inner tube is arranged in the shell, and the coil is arranged between the outer wall of the inner tube and the inner wall of the shell. A partition is arranged inside the inner tube along its cross section. The storage cavity is above the partition, and the liquid storage cavity is below the partition. The outlet of the gas transmission pipe passes through the top cover of the inner tube and enters the storage cavity. The inner tube located on the storage cavity side is provided with a plurality of through holes connecting the storage cavity and the shell cavity. The inner tube located on the liquid storage cavity side is provided with a plurality of connecting holes connecting the liquid storage cavity and the shell cavity. There is a refrigerant output pipe whose inlet is located below the liquid storage cavity. This patent uses the cavity of the inner tube as a lower buffer to allow the refrigerant to be sprayed more evenly on the surface of the coil, thereby improving the heat exchange effect. Obviously, the effective heat exchange area of ​​this coil-type heat exchanger is smaller than that of the shell-and-tube type heat exchanger. The shell-and-tube heat exchanger usually uses collectors at both ends of multiple parallel shells to collect the refrigerant and the coolant, but due to the limited length of the shell, the heat exchange time is short, resulting in insufficient heat exchange, making the shortcomings of the shell-and-tube type heat exchanger more obvious. Therefore, the development of a new type of heat exchanger is of great significance to improving the efficiency of heat pump water heaters and air conditioners. Summary of the invention

[0003] The purpose of the present invention is to provide a flange-connected dual-path topology isolated rotary tube heat exchanger, which is divided into at least two sections and is sealed and spliced ​​by flange plates. It has good processability and can achieve sufficient heat exchange between refrigerant and coolant to overcome the shortcomings of the prior art.

[0004] The present invention adopts the following technical solutions to achieve the above-mentioned purpose: a flange-connected dual-path topology isolation rotary tube heat exchanger, comprising at least two end covers, the end cover comprising an end cover body, a flange plate, and a plurality of U-tube cavities arranged in a directional and orderly manner, the U-tube cavity comprising a bend and a straight tube cavity, a sleeve tube cavity is arranged around the straight tube cavity, the two straight tube cavities of the U-tube cavity are connected through the bend, the end cover body is provided with a connecting cavity at the inner side of the U-tube cavity bend, the connecting cavity connects the two sleeve tube cavities of the U-tube cavity at the inner side of the bend, the flange plate is provided with a through channel adapted to the straight tube cavity and the sleeve tube cavity, so that after the flange plates of the two end covers are sealed and spliced, a reciprocating and circuitous forward-directed coolant flow channel is formed in the two end covers by the bend and the straight tube cavity, and a unique reciprocating and circuitous forward-directed refrigerant flow channel is formed by the connecting cavity; the end cover is formed by metal injection molding.

[0005] The flange is provided with fastening bolt holes.

[0006] The inner and outer wall surfaces of the cavity wall of the straight tube cavity are provided with thread-shaped rib grooves.

[0007] A connecting rib is provided between the cavity wall of the straight tube cavity and the inner wall of the communicating cavity.

[0008] It also includes an intermediate connector, which includes a sleeve part and flange parts at both ends of the sleeve part, the flange parts are respectively sealed and connected to the flange plates of the two end covers, the sleeve part includes a plurality of sleeves, the inner tube of the sleeve is adaptively connected to the straight tube cavity of the end cover, and the outer sleeve interlayer of the sleeve is connected to the sleeve cavity of the end cover.

[0009] The beneficial effects that can be achieved by the present invention using the above technical solution are:

[0010] 1) Metal injection molding technology has the advantages of one-time molding of complex-shaped products, high product dimensional accuracy, and no mechanical processing or only micro-processing. The metal powder and organic binder mixture injected into the mold is degreased and sintered to form the product. When the metal injection molding method is used to produce products, there is no need for a lateral core pulling mechanism in the mold. The core is vaporized during the subsequent heating process, making the external and internal spatial shape design and manufacturing of the parts manufactured by the metal injection molding method more free, and it is possible to achieve "hollow", "concave" or "undercut" spatial shapes that cannot be achieved by various traditional processing methods. By using metal injection molding technology, end caps, bends, connecting cavities, straight tube sleeves and flange structural parts that can achieve topological steering of the double-layer spatial structure of the sleeve can be manufactured. The inner layer of the inner tube and the interlayer space of the sleeve in the end cap can achieve spatial steering without intercommunication. The connecting parts that complete this two-way steering, such as the end cap described above, can be made into an integrated part. The realization of the two-way steering topological structure inside this end cap part can only be achieved by additive manufacturing such as 3D printing, except for metal injection molding technology. However, the 3D printing method is not applicable in actual mass production.

[0011] 2) Metal injection molding technology products have a strength similar to that of the metal used after sintering. The application of metal injection molding technology on heat exchangers can effectively solve the problem of manufacturing the 180-degree reciprocating turning connector end caps of straight-line casing pipes, realize the double-layer pipeline turning space topology structure parts that could not be realized by previous industrial production methods, and obtain the heat exchanger pipeline space layout structure that was previously restricted by various industrial production methods for heat exchangers. The introduction of metal injection molding technology has been expanded, so that the inner layer and interlayer space layout structure of the casing that is restricted by various existing manufacturing technologies has been greatly expanded. The number of straight-line casings can be increased as needed to achieve the accumulation of the total heat exchange process length of the casing. The number of casings N can be changed by changing the number of turns in the end cap as needed. This realization is only limited by the production capacity of the maximum size end cap that can be provided by the metal injection molding method. Theoretically, there is no upper limit. The refrigerant and coolant passages between multiple end caps can also continue to be connected, which provides a new design and manufacturing idea direction for improving the heat exchange efficiency of the heat exchanger. The complex spatial structure composed of the bends, connecting cavities, straight tube sleeves, flanges, threaded ribs, etc. on the end cover of the high-efficiency heat exchanger of the present invention must contain so-called "undercut", "hollow", and "concave" shapes that are difficult to demold during mold production due to the need for two-way 180-degree turns. These structures can only be produced through metal injection molding technology during mass production. The heat exchanger produced by this method has higher heat exchange efficiency and solves the problem of short heat exchange stroke of the sleeve heat exchanger in a simple and effective way. Its manufacturing process and product size specification parameters as a new design and manufacturing method still have great possibility of gradual optimization.

[0012] 3) The heat exchanger of the present invention is spliced ​​together at both end covers or sealedly connected to the middle sleeve at both end covers, and a reciprocating and circuitous refrigerant flow channel is formed by the bend and the straight tube cavity or the bend, the straight tube cavity, and the inner tube of the middle connector. The connecting cavity sleeve cavity of the two end covers or the outer sleeve interlayer of the middle connector and the sleeve cavity and the connecting cavity of the end covers form a unique reciprocating and circuitous refrigerant flow channel, so that the single tube channels or interlayer channels arranged side by side on the two end covers are connected in a "series" manner, so that the heat exchange pipeline can be infinitely lengthened, thereby increasing the heat exchange area and making the heat exchange pipeline more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of the heat exchanger of the present invention.

[0014] Figure 2 It is a schematic diagram of the end face structure of the end cover flange of the heat exchanger of the present invention.

[0015] Figure 3 Schematic diagram of the flow path of the heat exchanger of the present invention, in which arrows and arrow connecting lines indicate the flow direction. DETAILED DESCRIPTION

[0016] The present technical solution is described in detail below in conjunction with specific embodiments.

[0017] like Figure 1-3As shown, a flange-connected dual-path topology isolation rotary tube heat exchanger has an end cover 1 and an end cover 2, both of which are composed of an end cover body 10 and a flange 11. A plurality of U-tube cavities 12 are arranged in order in the end cover body 10, wherein the U-tube cavity includes a bend 121 and a straight tube cavity 122, and a sleeve tube cavity 123 is arranged around the straight tube cavity. The two straight tube cavities of the U tube cavity are connected through the bend, and the end cover body is provided with a connecting cavity 124 at the inner side of the U tube cavity bend. The connecting cavity connects the two sleeve tube cavities 123 of each U tube cavity on the end cover 1 and the end cover 2 at the inner side of the bend. Therefore, when the flanges of the two end covers are sealed and spliced ​​facing each other, the pipeline of a certain U tube cavity 12 of the end cover 1 is correspondingly connected to the U tube cavity 12 of the end cover 2, and then returns to the other U tube cavities 12 of the end cover 1, and the cycle is repeated. In addition to the U tube cavity 12, an inlet pipe 17 and an outlet pipe 18 are also required to be provided on the end cap 1 or the end cap 2, and a refrigerant flow channel inlet pipe 171 and a refrigerant flow channel outlet pipe 181 are respectively provided near the inlet pipe 17 and the outlet pipe 18, wherein the inlet pipe is connected to the first U tube cavity 12 of the pipeline flow, the outlet pipe section is connected to the last U tube cavity 12, and the refrigerant flow channel inlet pipe 171 and the refrigerant flow channel outlet pipe 181 are both connected to the sleeve cavity 123. Since the purpose of the heat exchanger is to exchange heat between two fluids of different substances, there must be another flow channel for heat exchange with the refrigerant flow channel surrounding the straight tube cavity 122 and the bend 121. Specifically, the sleeve cavity 123 and the connecting cavity 124 form a unique refrigerant flow channel with a circuitous direction. The direction of the refrigerant flow channel is the same as or opposite to the direction of the coolant flow channel. When the two directions are the same, a sleeve cavity 123 of the end cover 1 enters another sleeve cavity 123 of the U tube cavity along the bend 121 of the U tube cavity through the connecting cavity 124 of the bend, and then enters the sleeve cavity 123 of the end cover 2 along the tube cavity, and the cycle is repeated until it leaves the heat exchanger from the tube cavity outlet. As the inlet and outlet of the refrigerant flow channel, its opening is on the end cover 1 or the end cover 2, and follows the inlet pipe or outlet pipe section of the coolant flow channel. In order to connect the pipelines of the two end covers, through-channels (111, 112) adapted to the straight tube cavity and the sleeve cavity are provided on the flanges of the end covers, so that after the flanges of the two end covers are sealed and spliced, a reciprocating and circuitous refrigerant flow channel is formed in the two end covers by the bend 121 and the straight tube cavity 122, and a single reciprocating and circuitous refrigerant flow channel is formed by the sleeve cavity 123 and the connecting cavity 124. Since there is a U-shaped bend in the end cover, it is necessary to provide the connecting cavity 124 and the sleeve cavity 123.

[0018] The two flanges 11 are welded by sealing or brazing (e.g., salt bath brazing). When brazing, a brazing groove 180 is provided on one of the flanges, and a brazing wire is placed in the groove, and the two are welded together by a brazing process. Fastening bolt holes 113 are provided on the two flanges, and fastening bolts are pre-fixed to further fasten the two end covers by brazing operation.

[0019] Furthermore, in order to change the laminar flow phenomenon of the fluid in the heat exchange tube wall, spiral rib grooves (not shown) can be set on the inner and outer wall surfaces of the straight tube cavity to make the tube wall plane uneven, and the fluid micro-clusters no longer flow in parallel and in layers with each other without interfering with or mixing each other. Instead, turbulence is promoted, so that the fluid micro-clusters of the two fluids are strongly mixed and doped, and not only move along the mainstream direction, but also move perpendicular to the mainstream direction, thereby making the heat exchange effect more excellent.

[0020] The above is only a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A flange-connected dual-path topology isolation rotary tube heat exchanger, characterized in that: The invention comprises at least two end caps, wherein the end caps comprise an end cap body, a flange, and a plurality of U-tube cavities arranged in a directional and orderly manner, wherein the U-tube cavity comprises a bend and a straight tube cavity, a sleeve tube cavity is arranged around the straight tube cavity, and the two straight tube cavities of the U-tube cavity are connected through the bend, and the end cap body is provided with a connecting cavity at the inner side of the bend of the U-tube cavity, and the connecting cavity makes the two sleeve tube cavities of the U-tube cavity connected at the inner side of the bend, and the flange is provided with a through channel adapted to the straight tube cavity and the sleeve tube cavity, so that after the flanges of the two end caps are sealed and spliced, an S-shaped cooling medium is formed in the two end caps by the bend and the straight tube cavity. The invention relates to a refrigerant flow channel, a refrigerant flow channel with a circuitous direction formed by the connecting cavity; the end cover is formed by metal injection molding; the inner and outer wall surfaces of the cavity wall of the straight tube cavity are provided with threaded rib grooves; a connecting rib is provided between the cavity wall of the straight tube cavity and the inner wall of the connecting cavity; and an intermediate connector is also included, the intermediate connector includes a sleeve portion and flange portions at both ends of the sleeve portion, the flange portions are respectively sealed and connected with the flange plates of the two end covers, the sleeve portion includes a plurality of sleeves, the inner tube of the sleeve is adaptively connected with the straight tube cavity of the end cover, and the outer sleeve interlayer of the sleeve is connected with the sleeve cavity of the end cover.

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