CN-121972920-A - Double-effect copper pipe with external fins and internal threads for heat pump system and manufacturing method thereof

CN121972920ACN 121972920 ACN121972920 ACN 121972920ACN-121972920-A

Abstract

The invention relates to the technical field of copper part manufacturing, and discloses an external fin internal thread double-effect copper pipe for a heat pump system and a manufacturing method thereof, wherein the external fin internal thread double-effect copper pipe comprises the steps of melting a preset copper raw material, horizontally continuously casting, performing planetary rolling on a hollow copper pipe blank, coaxially sleeving a preset aluminum pipe on the outer side of the internal thread copper pipe, and performing expansion treatment on a composite pipe to form a plurality of groups of spiral fins on the copper-aluminum composite pipe blank in an inclined angle distribution mode to obtain the external fin internal thread double-effect copper pipe; the spiral fin structure with the inclined angle distribution is processed on the outer surface of the copper-aluminum composite tube blank, and vacuum annealing and inert gas cooling treatment are assisted, so that the formed outer fins have good shape consistency and mechanical stability, the stress concentration risk of the root of each fin is obviously reduced, the problem of stress cracking of copper integrated into one piece in the fin forming process is avoided by the integral structure, the further improvement of the height and density of each fin is ensured, and the effective heat exchange area of the air side of the heat pump system is further expanded.

Inventors

CHEN LIANG
QUAN YANJIE
YANG LIN
LI RUI

Assignees

珠海港隆金属有限公司

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (10)

1. The manufacturing method of the double-effect copper pipe with the external fin and the internal thread for the heat pump system is characterized by comprising the following steps: melting a preset copper raw material, and then carrying out horizontal continuous casting to form a hollow copper tube blank; planetary rolling is carried out on the hollow copper tube blank, and internal thread forming is carried out on the inner wall of the formed reduced-wall copper tube blank by using a spinning core head, so that an internal thread copper tube is obtained; coaxially sleeved with a preset aluminum pipe on the outer side of the internal thread copper pipe, and performing expansion treatment on the composite pipe to form a copper-aluminum composite pipe blank, wherein the pipe thickness of the preset aluminum pipe is smaller than that of the internal thread copper pipe; and forming a plurality of groups of spiral fins on the copper-aluminum composite tube blank in an inclined angle distribution mode, annealing the obtained outer fin composite tube in a vacuum environment, and cooling to room temperature in an inert gas atmosphere to obtain the double-effect copper tube with the inner threads of the outer fins.
2. The method for manufacturing the double-effect copper pipe with the external fins and the internal threads for the heat pump system, according to claim 1, is characterized in that the preset copper raw material is a mixture of oxygen-free copper and processing aids, the processing aids are one or more of phosphorus, boron, zirconium and calcium, and the mass ratio of the processing aids in the preset copper raw material is 0.015% -0.040%, and the balance is oxygen-free copper.
3. The method for manufacturing an external fin double-effect copper tube for a heat pump system according to claim 1, wherein the step of forming a hollow copper tube blank by horizontally continuously casting a predetermined copper raw material after melting comprises: Smelting a preset copper raw material based on vacuum induction, and then carrying out electromagnetic stirring to form a uniform copper melt; Carrying out multistage filtration on the uniform copper melt, and introducing inert gas into the uniform copper melt to carry out microbubble washing in the filtration process to obtain a clean copper melt; Introducing the clean copper melt into a water-cooling crystallizer provided with an annular crystallization cavity and a graphite inner mold for horizontal continuous forming to form a hollow tube blank with an initial setting blank shell; And periodically drawing the hollow tube blank in a pull-stop-reverse push mode to obtain a hollow copper tube blank.
4. The method for manufacturing an external fin internal thread double-effect copper tube for a heat pump system according to claim 1, wherein the step of planetary rolling the hollow copper tube blank comprises: straightening the surface pretreatment of the hollow copper tube blank, and applying radial compression combining revolution and autorotation to the straightened tube blank to perform cold initial rolling to obtain a transitional state wall-reducing tube section; subjecting the transition state wall-reducing pipe section to cyclic local loading for recrystallization control to form a grain refined copper pipe blank; and carrying out outlet cooling shaping on the grain refined copper pipe blank to obtain a wall-reduced copper pipe blank.
5. The method for manufacturing an external fin internal thread double-effect copper pipe for a heat pump system according to claim 1, wherein the step of forming internal threads on the inner wall of the formed reduced-wall copper pipe blank by using a spinning core head to obtain the internal thread copper pipe comprises the following steps: the method comprises the steps of adopting a multi-head spinning core head to axially insert the inner wall of a reduced-wall copper pipe blank for spin forming, wherein the front end of the multi-head spinning core head is provided with a progressive guiding cone section; synchronously performing radial compression and internal thread compaction on the spinning-formed copper pipe blank to obtain an internal thread pipe with stable size; and carrying out multi-pass blank drawing processing on the internal thread pipe at a preset pass reduction rate, and carrying out annealing treatment on the blank drawn internal thread pipe to obtain the internal thread copper pipe.
6. The method for manufacturing the double-effect copper tube with the internal thread of the outer fin for the heat pump system according to claim 1, wherein the step of coaxially sleeving a preset aluminum tube on the outer side of the internal thread copper tube, expanding the composite tube to form a copper-aluminum composite tube blank comprises the following steps: the outer surface of the internal thread copper pipe is subjected to multistage chemical cleaning, and after the internal thread copper pipe is subjected to interface lubrication, a preset aluminum pipe is sleeved on the outer side of the internal thread copper pipe, so that a primary coaxial composite pipe is obtained; Synchronously carrying out progressive expansion and partial rolling on the primary coaxial composite pipe to form a mechanically combined pipe blank; And (3) stabilizing the mechanically combined tube blank to obtain a copper-aluminum composite tube blank.
7. The method for manufacturing an external fin internal thread double effect copper tube for a heat pump system according to claim 1, wherein said step of forming a plurality of sets of spiral fins on said copper aluminum composite shell in an oblique angle distribution comprises: Pushing an inner supporting core rod into the copper-aluminum composite pipe blank, and then carrying out preheating treatment under the protection atmosphere of nitrogen, wherein the inner supporting core rod is made of preset hard alloy; continuously oblique rolling the preheated copper-aluminum composite pipe blank at a constant axial feeding speed in an oblique angle distribution manner to obtain a primary fin composite pipe; And (3) shaping and compacting the fins of the primary fin composite tube, and carrying out integral finishing on the end parts of the shaped and compacted fin composite tube to obtain the outer fin composite tube.
8. The method for manufacturing the double-effect copper tube with the internal thread of the outer fin for the heat pump system according to claim 1, wherein the step of annealing the obtained composite tube with the outer fin in a vacuum environment and cooling the composite tube to room temperature in an inert gas atmosphere to obtain the double-effect copper tube with the internal thread of the outer fin comprises the following steps: Performing diffusion annealing on the outer fin composite tube based on a vacuum environment, and placing the metallurgically bonded outer fin composite tube in an inert gas atmosphere for multi-stage cooling to room temperature to obtain an oxidation-free composite tube; And carrying out compound polishing on the non-oxidized compound tube, and carrying out compound nondestructive testing on the polished non-oxidized compound tube to obtain the double-effect copper tube with the external fins and the internal threads.
9. An external fin internal thread double-effect copper pipe for a heat pump system, which is characterized by being manufactured by adopting the manufacturing method of the external fin internal thread double-effect copper pipe for the heat pump system according to any one of claims 1-8, and comprising a copper pipe body and an aluminum pipe sleeve, wherein the aluminum pipe sleeve is coaxially sleeved on the outer peripheral side of the copper pipe body, and the opposite ends of the aluminum pipe sleeve are flush with the opposite ends of the copper pipe body; the inner side surface of the copper pipe body is provided with internal threads, the outer peripheral side of the aluminum pipe sleeve is provided with a plurality of spiral fins, the fins are connected with the two opposite ends of the aluminum pipe sleeve, and the fins are distributed in a circumferential array along the axial direction of the aluminum pipe sleeve, wherein the pipe thickness of the aluminum pipe sleeve is smaller than that of the copper pipe body.
10. The double-effect copper pipe with internal threads of an outer fin for a heat pump system according to claim 9, wherein a plurality of partition grooves which are spirally distributed are formed on the outer peripheral side of the aluminum pipe sleeve, the cross sections of the partition grooves are in a triangular shape, and the fins are formed between every two partition grooves; The pitch of the dividing grooves is larger than that of the internal threads.

Description

Double-effect copper pipe with external fins and internal threads for heat pump system and manufacturing method thereof Technical Field The invention relates to the technical field of copper piece manufacturing, in particular to an external fin internal thread double-effect copper pipe for a heat pump system and a manufacturing method thereof. Background The heat pump system is used as a high-efficiency and energy-saving heat and humidity treatment and energy lifting technology, and is widely applied to the fields of building air conditioning, industrial waste heat recovery, precise temperature control of data centers, clean heating and the like. The heat exchanger is a core heat exchange component of the heat pump system, and the performance of an internal reinforced heat transfer pipe (particularly a double-effect structure pipe with high-efficiency inner side phase change heat exchange and outer side air convection heat exchange) directly influences the energy-saving source efficiency ratio (SEER/SCOP) of the whole system in season, the compactness, the weight and the overall economy. With the continuous expansion of heat pump application scenes to wide temperature range, large temperature rise/drop and extreme climate conditions, industry has raised comprehensive requirements on heat exchange tubes, namely the inner side needs to have excellent boiling/condensation enhanced heat transfer capability, the outer side needs to have enough large effective heat exchange area, and meanwhile, the heat exchange tubes are light in weight, low in cost and long-term reliability. The existing double-effect reinforced pipe for the heat pump air side heat exchanger is mostly made of all-copper materials, and the inner wall fine internal threads and the outer surface fin structure are simultaneously realized through an integral forming process, so that the all-copper integrated double-effect copper pipe has better performance in terms of heat transfer performance and reliability, but is limited by factors of strength, mold bearing capacity and material flow characteristics of copper materials, if the height or density of fins is increased, serious stress concentration is easily generated at the root of the fins, and the defects of cracking of the root of the fins, micro-tearing of the surface, obvious uneven fin height along the axial direction and the like are caused, so that the expansion of the effective heat exchange area of the air side is limited. Therefore, it is necessary to provide an external fin internal thread double-effect copper pipe for a heat pump system and a manufacturing method thereof, so as to solve the problem that the existing double-effect copper pipe is easily subjected to serious stress concentration at the root of a fin due to the restriction of the strength of a copper material, the bearing capacity of a die and the flow characteristics of the material. Disclosure of Invention The invention mainly aims to provide an external fin internal thread double-effect copper pipe for a heat pump system and a manufacturing method thereof, and aims to solve the technical problems in the background art. The invention adopts the following technical scheme: An external fin internal thread double-effect copper pipe for a heat pump system and a manufacturing method thereof, comprising the following steps: melting a preset copper raw material, and then carrying out horizontal continuous casting to form a hollow copper tube blank; planetary rolling is carried out on the hollow copper tube blank, and internal thread forming is carried out on the inner wall of the formed reduced-wall copper tube blank by using a spinning core head, so that an internal thread copper tube is obtained; coaxially sleeved with a preset aluminum pipe on the outer side of the internal thread copper pipe, and performing expansion treatment on the composite pipe to form a copper-aluminum composite pipe blank, wherein the pipe thickness of the preset aluminum pipe is smaller than that of the internal thread copper pipe; and forming a plurality of groups of spiral fins on the copper-aluminum composite tube blank in an inclined angle distribution mode, annealing the obtained outer fin composite tube in a vacuum environment, and cooling to room temperature in an inert gas atmosphere to obtain the double-effect copper tube with the inner threads of the outer fins. Further, the preset copper raw material is a mixture of oxygen-free copper and a processing aid, the processing aid is one or more of phosphorus, boron, zirconium or calcium, and the processing aid accounts for 0.015% -0.040% of the preset copper raw material according to the mass ratio, and the balance is oxygen-free copper. Further, the step of forming the hollow copper pipe blank by horizontally continuously casting the molten preset copper raw material includes: Smelting a preset copper raw material based on vacuum induction, and then carrying out electromagnetic stirring to for