CN215864849U - Evaporation heat exchange tube - Google Patents

Abstract

The utility model relates to an evaporation heat exchange tube, it includes the circular shape body that is formed by the crooked welding of strap, the internal surface system of body has a plurality of channels of interval arrangement in order on the axial direction of this body, each in a plurality of channels is equallyd divide and is do not extended on the circumferencial direction of the axis of perpendicular to body, the width of groove road junction is less than the channel diapire, the channel diapire is provided with the uplift portion to groove road junction uplift, all has acute angle contained angle between each channel lateral wall in two channel lateral walls and the channel diapire, the channel diapire has more greatly than the channel junction the ascending width size of axial direction, and first channel lateral wall is "eight" style of calligraphy setting with second channel lateral wall. This application is with the heat transfer effect who improves the evaporation heat exchange tube. This application pertinence ground designs the small channel of heat exchange tube internal surface, through the optimal design to the channel structure, has strengthened its capillary force, improves the heat transfer effect of evaporation heat exchange tube.

Description

Evaporation heat exchange tube

Technical Field

The application relates to the field of heat exchange tubes, in particular to an evaporation heat exchange tube.

Background

There are two main types of evaporators: flooded evaporators and dry evaporators. In the flooded evaporator, the heat exchange tube is completely immersed in refrigerant liquid, and the refrigerant can be fully contacted with the wall surface of the heat exchange tube; the dry evaporator has the heat exchange capacity about half that of a flooded evaporator because the refrigerant in the tube is limited by the flow pattern and the refrigerant cannot be in full contact with the wall surface of the heat exchange tube. Specifically, the operation of the dry evaporator is as follows: low-temperature working media such as Freon flow through the heat exchange tubes, and the low-temperature working media and the hot fluid outside the tubes exchange heat to generate phase change to form steam. I.e. liquid at the inlet and vapour at the outlet. The phase change process of the material has gas phase, liquid phase and gas-liquid interface, and the two-phase mass, momentum and energy exchange exists between the interfaces. Since the gas phase is compressible, the interface is easily deformed, and thus, a different combination of interfaces, i.e., a flow pattern transition, is formed during the flow. For a horizontal dry evaporator with the heat exchange tubes arranged horizontally, the flow pattern within the tubes includes: bubble flow, plug flow, laminar flow, wavy flow, bulk flow, and annular flow. The partial flow regime in these flow regimes is: under the action of gravity, the liquid is in a gas state at the lower part and the upper part of the heat exchange tube, such as laminar flow, wavy flow, plug flow and the like. In this case, only a part of the heat transfer area is in contact with the liquid refrigerant to cause a phase change, and the other part of the heat transfer area is in contact with the gas phase only without a phase change. The reinforced heat exchange tube adopted in the existing dry evaporator is an internal threaded tube, namely, a plurality of spiral channels are arranged on the inner wall surface of the heat exchange tube.

The Chinese patent CN85103367A discloses a technology as follows: the inner surface of the heat exchange tube is provided with a plurality of spiral grooves, and the cross section of the ridge between the spiral grooves of each spiral groove is triangular or trapezoidal, so that the cross section of each spiral groove is triangular or trapezoidal correspondingly.

The Chinese patent CN2539948Y discloses a technology as follows: the inner surface is provided with a plurality of thread teeth, the cross section of the tooth shape is triangular, and thread grooves between adjacent thread teeth are trapezoidal; the teeth are provided with small cutting ridge grooves at regular intervals along the tooth tops, so that the pipe is called an interrupted-tooth internal thread pipe.

The inventor of the above patent emphasizes that the spiral groove on the inner surface plays a role of a disturbance element, and can disturb the flow of the fluid, so as to destroy the boundary layer of the single-phase fluid, strengthen the convective heat transfer and improve the heat transfer coefficient. However, there is still room for further optimization.

Disclosure of Invention

The inventor considers that after a large amount of experiments and research analysis: the micro-grooves on the inner surface of the heat exchange tube can also play the role of a liquid absorption core. According to hydromechanics, the micro-fine groove can generate a capillary pressure head, the pressure head can overcome the action of gravity, liquid at the bottom of the heat exchange tube is conveyed to a position above the liquid level, the original area which is only in contact with a gas phase is wetted, the contact area of a refrigerant and a heat exchange surface is increased, and therefore the heat exchange efficiency is improved. The size of the capillary head determines how much liquid is transported, and the size of the capillary head is influenced by the geometry of the capillary channel, in addition to the properties of the liquid and the wall material. The maximum capillary head of a capillary channel is represented by the formula:

wherein:

Δ Pmax — maximum capillary head;

σ - - - -surface tension;

rc — effective capillary radius.

The effective capillary radius in equation (1) is related to the micro-capillary channel geometry. At present, most of spiral channels in the conventional heat exchange tubes are in a ladder shape with large openings and small bottom edges, the capillary action is very limited, and the liquid conveying capacity is greatly limited. Meanwhile, due to the limitation of processing conditions, the channels in the existing heat exchange tubes are all spiral, when liquid is conveyed to a certain vertical height, the flowing distance of the liquid along the channels is long, the upward conveying of the liquid is influenced, the liquid quantity of the upper wall surfaces in the tubes is reduced, the phenomenon of severe drying of the upper wall surfaces in the heat exchange tubes is caused, and the heat exchange performance of the heat exchange tubes is not promoted.

In addition, the heat exchange process of the dry-type evaporation tube is a flow boiling process, and the mechanism thereof comprises: convective heat transfer and nucleate boiling. The efficiency of nucleate boiling is improved mainly by three ways: increasing the number of vaporization cores, enhancing the heat exchange during the bubble growth process and increasing the bubble shedding frequency, i.e. reducing the bubble shedding size. The current popular commercial internal thread evaporating tube is provided with a plurality of trapezoidal and rectangular channels on the inner surface, and the geometric shape of the trapezoidal channels is characterized by a geometric shape with a large upper opening and a small bottom edge. According to the boiling heat exchange theory of heat transfer science, the geometrical shapes are not beneficial to increasing the number of gasification cores and activation cores, and are also not beneficial to the process of heating and growing up bubbles and the process of separating the bubbles from a heat exchange surface, namely the process of removing bodies.

Based on the analysis, the application provides an evaporation heat exchange tube to promote the heat transfer effect of evaporation heat exchange tube.

The technical scheme of the application is as follows:

an evaporating heat exchange tube comprising a circular tube body formed by bending and welding metal strips, the tube body having an inner surface formed with a plurality of channels arranged at intervals in succession in an axial direction of the tube body, each of the plurality of channels extending in a circumferential direction perpendicular to an axis of the tube body, respectively;

for each of the plurality of channels respectively comprising:

a channel opening and a channel bottom wall oppositely arranged in the radial direction of the pipe body, an

A first channel side wall and a second channel side wall disposed opposite in the axial direction;

the slot opening includes a first edge and a second edge disposed opposite in the axial direction, the slot bottom wall including: a third edge and a fourth edge which are oppositely arranged in the axial direction, a first bottom wall surface which extends from the third edge, and a second bottom wall surface which extends from the fourth edge, wherein the first bottom wall surface and the second bottom wall surface are arranged at an included angle and form a bulge part which is bulged towards the groove opening, the first groove channel side wall is directly connected between the first edge and the third edge, a first acute included angle is formed between the first groove channel side wall and the first bottom wall surface, the second groove channel side wall is directly connected between the second edge and the fourth edge, a second acute included angle is formed between the second groove channel side wall and the second bottom wall surface, and the first groove channel side wall, the second groove channel side wall, the first bottom wall surface, the second bottom wall surface and the groove channel have the same length dimension in the circumferential direction, the channel bottom wall has a width dimension in the axial direction that is greater than the channel opening, and the first channel side wall and the second channel side wall are arranged in a splayed shape.

In an alternative design, any cross section of the first channel side wall in the axial direction, any cross section of the second channel side wall in the axial direction, any cross section of the first bottom wall surface in the axial direction, and any cross section of the second bottom wall surface in the axial direction are all linear shapes.

In an alternative design, the first bottom wall surface is directly connected to the second bottom wall surface, so that the ridge in the shape of the sharp corner is formed.

In an alternative design, the first bottom wall surface and the second bottom wall surface are symmetrically disposed on two sides of a plane, and the first channel side wall and the second channel side wall are also symmetrically disposed on two sides of the plane, wherein the plane is perpendicular to the axis of the pipe body.

In an alternative design, the first acute included angle and the second acute included angle are equal and are both 40-60 degrees.

In an alternative design, the channel mouth has a width dimension in the axial direction of 0.15-0.35mm, the channel bottom wall has a width dimension in the axial direction of 0.5-1.2mm, and the channel has a depth dimension in the radial direction of 0.3-0.4 mm.

In an alternative design, the plurality of channels are arranged at equal intervals in the axial direction, the inner surface of the pipe body between any two adjacent channels is a smooth surface parallel to the axis of the pipe body, and the interval distance between two adjacent channels is 1.3-1.5 times of the width dimension of the bottom wall of each channel in the axial direction.

In an alternative design, each of the plurality of channels is a closed circular channel.

The application has at least the following beneficial effects:

1, this application pertinence ground designs the small channel of heat exchange tube internal surface, through the optimal design to the channel structure, has strengthened its capillary force, improves the heat transfer effect of evaporation heat exchange tube. Specifically, the bottom wall of the channel is provided with an outward bulge structure, two independent acute-angle corner area channels extending along the length direction of the channel are formed between two side walls and the bottom wall in the channel, and the width dimension of the channel opening is reduced. When the heat exchange tube is horizontally arranged and applied, the amount of liquid in the channel is gradually reduced from bottom to top along the extension direction of the channel, when the liquid in the channel retracts into the acute-angle corner channel from the channel opening, the curvature radius of the liquid level of the liquid in the channel is remarkably reduced, the generated capillary force is remarkably increased, and the acute-angle corner channel generates remarkable 'pumping' action, so that more liquid can be promoted to wet the upper dry wall surface in the heat exchange tube, more steam is generated, the problem of uneven distribution of liquid films on the inner surface of the dry-type evaporation heat exchange tube is favorably solved, and the evaporation heat exchange capacity of the heat exchange tube is improved.

And the liquid in the acute angle zone channel is less and less from bottom to top along the extension direction of the acute angle zone channel, and due to the triangular (section) structure of the acute angle zone channel, the curvature radius of the liquid level of the liquid in the acute angle zone channel is obviously reduced in the extension direction of the channel, the generated capillary force is larger, more liquid can be promoted to wet the upper dry wall surface in the heat exchange tube, and more steam is generated.

2, the important factor for strengthening the nucleate boiling process is to try to increase the number of vaporization cores, so as to increase the number of bubbles and increase the heat exchange efficiency. Based on theoretical analysis and experimental observation of heat transfer, the inventor finds that the conical cavities, namely the triangular cavities, are easy to generate vaporization cores or retain residues of bubbles, can reduce the required energy in the bubble growth process, and improve the activation degree of the bubble cores. Theories and experiments prove that the included angle of the conical cavity is an acute angle to produce the effect, and the smaller the included angle, the better the included angle. This application is the ascending uplift of contained angle form in the setting of channel diapire, and it is littleer with the adjustable contained angle of channel both sides wall, is favorable to the promotion of capillary force, the formation of gasification core and the growth of bubble.

3, the channel adopts a dovetail shape with a small upper opening and a large bottom edge, thereby forming a cavity structure with a larger space at the lower part, meanwhile, the upper opening of the dovetail groove forms a narrow slit shape, and the narrow slits become a passage for connecting the cavity and the refrigerant outside the cavity, thereby forming an outlet of the air bubbles in the cavity. Under the action of the superheat degree of the wall surface, a large amount of steam can be generated in the cavity, and at the moment, the narrow-slit-shaped width of the cavity outlet determines the size of the diameter of the steam bubble removal body. When the width of the narrow slit is small, the diameter of the stripping body of the air bubble is small; otherwise, it is larger. In practice, the size of the slit may be determined according to the surface tension of the refrigerant.

4, the dovetail-shaped channels in the present application facilitate heat exchange during bubble growth. The theory of heat transfer proves that after a vaporization core and small bubbles appear, a thin liquid film exists between the bubbles and a heating surface, and under the heating condition, the thin liquid film is continuously evaporated, and heat and mass are supplemented to the bubbles to continuously grow until the bubbles reach the shedding diameter and leave the wall surface. In this case, the thickness of the thin liquid film becomes a factor that affects the magnitude of the thermal resistance. In the dovetail-shaped channel structure, the outlet of the cavity is a narrow slit, so that bubbles generated in the cavity cannot leave immediately, the bubbles expand in the cavity after being heated, a thin liquid film between the bubbles and the heating surface is squeezed, and the heat transfer resistance of the heating surface to the bubbles is reduced. Under the general boiling condition, the bubble on the heating surface can only with heating surface one face contact, and in this application, the bubble in the cavity is heated and expands under the restraint of export slot, can contact with other wall in the hole among the expansion process to increased the heated area of bubble, can also squeeze the thin liquid film between thin bubble and the heating surface, reduced the thermal resistance, and then promoted heat transfer effect.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description only relate to some embodiments of the present application and are not limiting on the present application.

Fig. 1 is a schematic structural view of an evaporation heat exchange tube in an embodiment of the present application after being partially expanded.

FIG. 2 is a schematic sectional view taken along line A-A in FIG. 1.

Fig. 3 is an enlarged schematic view of a portion B of fig. 2.

Fig. 4 is a partial structural schematic view of a rolling wheel in an embodiment of the present application.

Fig. 5 is a schematic structural diagram of the metal strip processed in step S102 in the embodiment of the present application.

FIG. 6 is a graph showing the relationship between the angle of the triangular groove and the elevation height of the water in the groove, in which the abscissa is the value of the included angle of the triangular groove and the ordinate is the elevation height of the water in the groove under a vertical condition.

Fig. 7 is a graph comparing heat exchange performance of an evaporating heat exchange tube and a smooth tube heat exchange tube in the present embodiment, in which the horizontal axis represents mass flow rate, the vertical axis represents boiling heat exchange coefficient, the round black dots represent the heat exchange tube of the present embodiment, and the square black dots represent the smooth tube heat exchange tube.

Description of reference numerals:

1-a pipe body;

1 a-a weld;

101-a channel;

1011-channel mouth, 1012-channel bottom wall, 1013-first channel side wall, 1014-second channel side wall;

1011 a-first edge, 1011 b-second edge, 1012 a-third edge, 1012 b-fourth edge;

10121-a first bottom wall surface, 10122-a second bottom wall surface;

β 1-a first acute included angle, β 2-a second acute included angle;

p-plane;

2-rolling wheels;

201-rolling convex ribs;

201a-V shaped groove;

3-a metal strip;

301-linear grooves;

301a-V shaped protrusions;

302-straight line spacer bar.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings of the embodiments of the present application. It should be apparent that the described embodiments are only some of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the application without any inventive step, are within the scope of protection of the application. It will be understood that some of the technical means of the various embodiments described herein may be replaced or combined with each other without conflict.

In the description of the present application and claims, the terms "first," "second," and the like, if any, are used solely to distinguish one from another as between described objects and not necessarily in any sequential or technical sense. Thus, an object defined as "first," "second," etc. may explicitly or implicitly include one or more of the object. Also, the use of the terms "a" or "an" and the like, do not denote a limitation of quantity, but rather denote the presence of at least one of the two, and "a plurality" denotes no less than two.

In the description of the present application and in the claims, the terms "connected," "mounted," "secured," and the like are used broadly, unless otherwise indicated. For example, "connected" may be a separate connection or may be integrally connected; can be directly connected or indirectly connected through an intermediate medium; may be non-detachably connected or may be detachably connected. The specific meaning of the foregoing terms in the present application can be understood by those skilled in the art as appropriate.

In the description of the present application and in the claims, if there is an orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", etc. based on the orientation or positional relationship shown in the drawings, it is only for the convenience of clearly and simply describing the present application, and it is not indicated or implied that the elements referred to must have a specific direction, be constructed and operated in a specific orientation, and these directional terms are relative concepts for the sake of description and clarification and may be changed accordingly according to the change of orientation in which the elements in the drawings are placed. For example, if the device in the figures is turned over, elements described as "below" other elements would then be oriented "above" the other elements.

In the description of the specification and claims of this application, the term "configured to" if present is generally interchangeable with "… capable", "designed to", "for", or "capable", depending on the context.

Embodiments of the present application will now be described with reference to the accompanying drawings.

Fig. 1 to 3 show one embodiment of the evaporating heat exchange tube of the present application, which is a welded tube comprising a circular tube body 1 formed by bending and welding a metal strip 3. The inner surface of the pipe body 1 is formed with a plurality of grooves 101 arranged at intervals in series in the axial direction of the pipe body 1, and each of the grooves 101 extends in a circumferential direction perpendicular to the axis of the pipe body 1.

Each of the above-mentioned channels 101 respectively includes: a channel mouth 1011 and a channel bottom wall 1012 oppositely disposed in the radial direction of the pipe body 1, and a first channel side wall 1013 and a second channel side wall 1014 oppositely disposed in the axial direction of the pipe body 1. Wherein:

the notch 1011 includes a first edge 1011a and a second edge 1011b that are disposed opposite to each other in the axial direction of the pipe body 1. Channel bottom wall 1012 includes: a third edge 1012a and a fourth edge 1012b that are oppositely disposed in the axial direction of the pipe body 1, a first bottom wall surface 10121 that extends from the third edge 1012a, and a second bottom wall surface 10122 that extends from the fourth edge 1012 b. The first bottom wall surface 10121 and the second bottom wall surface 10122 are arranged at an included angle, so that a bulge part bulging towards the groove opening 1011 is formed. The first bottom wall surface 10121, the second bottom wall surface 10122 and the channel 101 have the same length dimension in the circumferential direction. The first channel side wall 1013 is directly connected between the first edge 1011a and the third edge 1012a, and the first channel side wall 1013 and the first bottom wall surface 10121 have a first acute included angle β 1 therebetween. Second channel side wall 1014 is directly connected between second edge 1011b and fourth edge 1012b, and second channel side wall 1014 has a second acute included angle β 2 with second bottom wall face 10122. The channel 101 is a dovetail groove structure with a channel bottom wall 1012 having a greater width dimension in the axial direction of the pipe body than the channel mouth 1011.

As represented by formula (1) in the summary of the invention section of the application: maximum capillary head and effective capillary radius r of capillary channel_cAnd (4) correlating. While different channels have different effective capillary radii. The effective capillary radii of the rectangular channels, triangular channels and semicircular channels are shown in table 1 below:

table 1: different capillary channel and effective capillary radius r_c

In the slot channel of the approximate dovetail shape, two included angles formed by two waists (the first slot channel side wall and the second slot channel side wall) and a bottom edge (the bottom wall of the slot bottom) are acute angles. Specifically, a first acute included angle β 1 between a first channel side wall 1013 and a channel bottom wall 1012, particularly a first bottom wall face 10121 of the channel bottom wall 1012, and a second acute included angle β 2 between a second channel side wall 1014 and a channel bottom wall 1012, particularly a second bottom wall face 10122 of the channel bottom wall 1012, form a sharp-angled region that can be used as a passage for liquid flow and is a triangular passage. When the heat exchange tube is horizontally arranged and applied, liquid in the channel 101 is gradually reduced along with the upward extension of the channel 101 above the liquid level in the heat exchange tube, and when the liquid is retracted into the sharp-angled area, the sharp-angled area can be used as a liquid flow channel and can be regarded as a triangular channel. As shown in table 1 above, when the vertex angle (corresponding to β 1, β 2) of the triangle is a small acute angle, the corresponding cos β is approximately equal to 1, the generated capillary force is large, and more liquid can be promoted to wet the upper dry wall surface in the heat exchange tube, so as to generate more steam. Also, the opening width of the triangular channel is smaller than the rectangular channel opening, and thus it can be judged that the capillary head of such a channel 101 of the present embodiment is significantly larger than the rectangular channel.

When the heat exchange tube is horizontally arranged and applied, compared with the traditional rectangular channel, in the embodiment, the amount of liquid in the channel 101 is less and less from bottom to top along the extension direction of the channel 101, when the liquid in the channel retracts into the sharp-angled area, the curvature radius of the liquid level of the liquid in the channel 101 is obviously reduced, the generated capillary force is large, more liquid can be promoted to wet the upper dry wall surface in the heat exchange tube, and more steam is generated.

In fig. 6, the abscissa is the included angle value of the triangular groove, and the ordinate is the lifting height of the water in the groove under the vertical condition. The experimental results show that the smaller the angle, the higher the water lift in the groove, demonstrating that the smaller the angle, the greater the capillary force of the groove. Thus, the present embodiment further arranges the first bottom wall surface 10121 and the second bottom wall surface 10122 of the channel bottom wall 1012 at an included angle that is raised toward the channel port 1011, so that the first acute included angle β 1 or the second acute included angle β 2 is smaller, and the generated capillary force is larger.

The slot channel adopts a dovetail shape with a small upper opening and a large bottom edge, thereby forming a cavity structure with a larger space at the lower part, and the upper opening of the dovetail groove forms a narrow slit shape, and the narrow slits become a passage for connecting the cavity and refrigerant outside the cavity, thereby forming an outlet of air bubbles in the cavity. Under the action of the superheat degree of the wall surface, a large amount of steam can be generated in the cavity, and at the moment, the narrow-slit-shaped width of the cavity outlet determines the size of the diameter of the steam bubble removal body. When the width of the narrow slit is small, the diameter of the stripping body of the air bubble is small; otherwise, it is larger. In practice, the size of the slit may be determined according to the surface tension of the refrigerant.

Moreover, the dovetail-shaped channels facilitate heat exchange during bubble growth. The theory of heat transfer proves that after a vaporization core and small bubbles appear, a thin liquid film exists between the bubbles and a heating surface, and under the heating condition, the thin liquid film is continuously evaporated, and heat and mass are supplemented to the bubbles to continuously grow until the bubbles reach the shedding diameter and leave the wall surface. In this case, the thickness of the thin liquid film becomes a factor that affects the magnitude of the thermal resistance. In the dovetail-shaped channel structure, the outlet of the cavity is a narrow slit, so that bubbles generated in the cavity cannot leave immediately, the bubbles expand in the cavity after being heated, a thin liquid film between the bubbles and the heating surface is squeezed, and the heat transfer resistance of the heating surface to the bubbles is reduced. Under the general boiling condition, the bubble on the heating surface can only with heating surface one face contact, and in this application, the bubble in the cavity is heated and expands under the restraint of export slot, can contact with other wall in the hole among the expansion process to increased the heated area of bubble, can also squeeze the thin liquid film between thin bubble and the heating surface, reduced the thermal resistance, and then promoted heat transfer effect.

In the present embodiment, any cross section of the first channel side wall 1013 in the axial direction of the pipe body 1, any cross section of the second channel side wall 1014 in the axial direction of the pipe body 1, any cross section of the first bottom wall surface 10121 in the axial direction of the pipe body 1, and any cross section of the second bottom wall surface 10122 in the axial direction of the pipe body 1 are all linear shapes.

In the present embodiment, the first bottom wall surface 10121 and the second bottom wall surface 10122 are directly connected, thereby forming the above-described ridge portion in a pointed shape. The first bottom wall surface 10121 and the second bottom wall surface 10122 are directly connected, so that the depth of the triangular channel can be increased, and more liquid can wet the upper dry wall surface in the heat exchange tube to generate more steam.

In the present embodiment, the first bottom wall surface 10121 and the second bottom wall surface 10122 have the same area size, and are symmetrically disposed on both sides of a plane P perpendicular to the axis of the pipe body 1. The first channel side wall 1013 and the second channel side wall 1014 also have the same area size and are also symmetrically disposed on either side of the aforementioned plane P.

The first acute included angle beta 1 is equal to the second acute included angle beta 2, and the first acute included angle beta 1 and the second acute included angle beta 2 are preferably 40-60 degrees, so that the preparation of the channel 101 structure is facilitated, and a good drying-resistant effect can be obtained. Specifically, in the present embodiment, the first acute included angle β 1 and the second acute included angle β 2 are both 40 °.

The size of the channel 101 should not be too large or too small. In general, the width dimension of the slot 1011 in the axial direction of the pipe body 1 is preferably 0.15 to 0.35mm, and in this embodiment is specifically 0.8 mm. The channel bottom wall 1012 has a width dimension of 0.5 to 1.2mm, specifically 1.0mm in the present embodiment, in the axial direction of the pipe body 1. The depth dimension of the channel 101 in the radial direction of the tubular body 1 is preferably 0.3-0.4mm, in this embodiment 0.3 mm.

In this embodiment, the grooves 101 are arranged at equal intervals in the axial direction of the pipe body 1, and the inner surface of the pipe body 1 between any two adjacent grooves 101 is a smooth surface parallel to the axis of the pipe body 1. The spacing distance between two adjacent channels 101 is preferably 1.3 to 1.5 times the width dimension of the channel bottom wall 1012 in the axial direction.

In order to achieve a better anti-run-dry effect when the heat exchange pipe is discharged horizontally or approximately horizontally at any angle (an angle pivoted around the axis of the pipe), each channel 101 is designed to be a closed circular ring channel, obviously the circular channel surrounds the periphery of the axis of the pipe body 1.

In this embodiment, the outer diameter of the pipe body 1 is 9.52 mm. In order to test the heat exchange performance of the heat exchange tube, a comparison experiment of the heat exchange performance is carried out on the heat exchange tube and the smooth tube heat exchange tube of the embodiment, wherein the inner surface of the smooth tube heat exchange tube is a smooth surface without a channel structure, and the material and the size of the smooth tube heat exchange tube are the same as those of the heat exchange tube of the embodiment. The refrigerant used in the experiment was R410A, with an inlet quality x of 0.2 and an outlet quality x of 0.45. The experimental results are shown in fig. 7, in which the abscissa is the mass flow rate of R410A and the ordinate is the evaporation heat transfer coefficient in the tube, and the circle black dots represent the heat exchange tube of the present embodiment and the square black dots represent the smooth tube heat exchange tube. The experimental results of fig. 7 show that the heat exchange tube of this example has an evaporative heat transfer coefficient of at most 2.1 times that of the light pipe.

In addition, the embodiment also provides a method for manufacturing the evaporation heat exchange tube, which comprises the following steps:

and S101, providing the metal strip 3 and the rolling wheel 2, wherein the rolling surface of the rolling wheel 2 is provided with a rolling convex rib 201 protruding outwards, the rolling convex rib 201 extends in the circumferential direction perpendicular to the axis of the rolling wheel 2, and the top of the rolling convex rib 201 is provided with a V-shaped groove 201a corresponding to the sharp-horn-shaped bulge.

In order to improve the quality of the product, the metal belt 3 may be cleaned with chemicals, and after the metal belt 3 to be cleaned is dried, the metal belt 3 may be trimmed to make the width and thickness of the metal belt 3 uniform.

The metal strip 3 can be made of various grades of titanium steel, stainless steel, carbon steel, aluminum or copper.

S102, rolling a plurality of linear grooves 301 arranged in parallel in a first direction on the surface of the metal strip 3 by using a rolling wheel 2, and forming a linear spacer 302 having a rectangular cross section between any two adjacent linear grooves 301.

It can be understood that, since the top of the rolled rib 201 has the V-shaped groove 201a corresponding to the pointed ridge, after the step is completed, the bottom of the formed linear groove 301 has the V-shaped protrusion 301a extending linearly, and the V-shaped protrusion 301a corresponds to the ridge.

For the convenience of subsequent welding, two ends of the linear groove are spaced from the edge of the metal strip to leave a smooth narrow edge of 0.5-3 mm.

And S103, rolling the top of the linear spacer 302 to enable the top of the linear spacer 302 to extend outwards in the first direction.

It will be appreciated that when the top of the linear spacer 302 is subjected to mechanical compression in the height direction, deformation is produced which extends to both sides of the width, and this deformation results in the linear spacer 302 being substantially an inverted isosceles trapezoid, the two legs of which correspond to the first channel side wall 1013 and the second channel side wall 1014, respectively.

S104, bending the metal belt 3, enabling two opposite side edges of the metal belt 3 to be in mutual contact to form a straight seam, and welding the straight seam by adopting an argon arc welding process to form a welded pipe.

After the step S104 is completed, the welding seam of the welded pipe can be inspected by using an online eddy current flaw detector to ensure tight welding, and after the quality of the welding seam is confirmed to reach the standard, the welded pipe is subjected to solution treatment in a protective atmosphere to improve the quality of the welded pipe. The protective atmosphere may be a mixed atmosphere of 25 mass% nitrogen and 75 mass% hydrogen, and the temperature of the solution treatment is preferably 1020 to 1100 ℃.

The above are exemplary embodiments of the present application only, and are not intended to limit the scope of the present application, which is defined by the appended claims.

Claims (8)

1. An evaporating heat exchange tube comprising a circular tube body (1) formed by bending and welding a metal strip (3), characterized in that the inner surface of the tube body (1) is formed with a plurality of channels (101) arranged at intervals in sequence in the axial direction of the tube body (1), each of the plurality of channels (101) extending in a circumferential direction perpendicular to the axis of the tube body (1), respectively;

each of the plurality of channels (101) comprises:

a channel mouth (1011) and a channel bottom wall (1012) arranged opposite in the radial direction of the pipe body (1), and

a first channel sidewall (1013) and a second channel sidewall (1014) oppositely disposed in the axial direction;

the channel mouth (1011) includes a first edge (1011a) and a second edge (1011b) disposed opposite in the axial direction, the channel bottom wall (1012) includes: a third edge (1012a) and a fourth edge (1012b) oppositely arranged in the axial direction, a first bottom wall surface (10121) extending from the third edge (1012a), and a second bottom wall surface (10122) extending from the fourth edge (1012b), the first bottom wall surface (10121) being arranged at an angle to the second bottom wall surface (10122) and forming a bulge rising towards the channel opening (1011), the first channel side wall (1013) being directly connected between the first edge (1011a) and the third edge (1012a), and the first channel side wall (1013) having a first acute angle (β 1) with the first bottom wall surface (10121), the second channel side wall (1014) being directly connected between the second edge (1011b) and the fourth edge (1012b), and the second channel side wall (1014) having a second acute angle (β 2) with the second bottom wall surface (10122), the first channel side wall (1013), the second channel side wall (1014), the first bottom wall surface (10121), the second bottom wall surface (10122), and the channel (101) have the same length dimension in the circumferential direction, the channel bottom wall (1012) has a width dimension in the axial direction larger than the channel mouth (1011), and the first channel side wall (1013) and the second channel side wall (1014) are provided in a shape of "eight".

2. The evaporating heat exchange tube of claim 1, wherein any cross section of said first channel sidewall (1013) in said axial direction, any cross section of said second channel sidewall (1014) in said axial direction, any cross section of said first bottom wall surface (10121) in said axial direction, and any cross section of said second bottom wall surface (10122) in said axial direction are all linear shapes.

3. The evaporating heat exchange tube of claim 2, wherein said first bottom wall surface (10121) is directly joined to said second bottom wall surface (10122) so as to form said ridge in a pointed shape.

4. An evaporating heat exchange tube according to claim 3, wherein said first bottom wall surface (10121) and said second bottom wall surface (10122) are symmetrically disposed on either side of a plane (P) to which said first channel sidewall (1013) and said second channel sidewall (1014) are also symmetrically disposed, wherein said plane (P) is perpendicular to the axis of said tube body (1).

5. An evaporating heat exchange tube according to claim 4, wherein said first acute included angle (β 1) and said second acute included angle (β 2) are equal and are both 40 ° -60 °.

6. The evaporative heat exchange tube of claim 1, wherein the channel mouth (1011) has a width dimension in the axial direction of 0.15-0.35mm, the channel bottom wall (1012) has a width dimension in the axial direction of 0.5-1.2mm, and the channel (101) has a depth dimension in the radial direction of 0.3-0.4 mm.

7. An evaporating heat exchange tube according to claim 1, wherein said plurality of channels (101) are arranged at regular intervals in said axial direction in order, and the inner surface of said tube body (1) between any adjacent two of said channels (101) is a smooth surface parallel to the axis of said tube body (1), and the distance between adjacent two of said channels (101) is 1.3 to 1.5 times the width dimension of said channel bottom wall (1012) in said axial direction.

8. The evaporative heat exchange tube according to any one of claims 1 to 7, wherein each of the plurality of channels (101) is a closed circular ring shaped channel.

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