CN102449424B

CN102449424B - Heat-transfer pipe

Info

Publication number: CN102449424B
Application number: CN201080022922.2A
Authority: CN
Inventors: 辻本真也; 森康敏; 松崎静夫
Original assignee: Furukawa Electric Co Ltd
Current assignee: Corporation Armored Pure Copper Tube; Emkeper Seventh LLC
Priority date: 2009-05-28
Filing date: 2010-05-27
Publication date: 2015-09-30
Anticipated expiration: 2030-05-27
Also published as: KR101695044B1; JP2010276270A; CN102449424A; WO2010137647A1; KR20130131499A; JP5435460B2

Abstract

The present invention aims to provide one and the pressure loss can be suppressed to increase, and improves the heat-transfer pipe of pipe thermal conductivity.Heat-transfer pipe (11) external diameter is less than 7mm, is formed have special angle (β at the relative tube axial direction (D1) of pipe inner face (10) ₁) height (H _f) be the screw-shaped radiator fins (12) of 0.1mm ~ 0.30mm, fin (12) is by depth H _nfor helical form counter drain (14) segmentation of 0.1mm ~ 0.30mm forms fin constituting portion (12A).In at least hand of spiral downstream (D2d) of fin constituting portion (12A), between the fin (12) that tube axial direction upstream side (D1u) is adjacent, there is the protrusion tab (16) that relative fin (12) has angle α (5 °≤α < 70 °).The structure of fin constituting portion (12A) comprising: form the interval (P between the fin constituting portion (12A) on direction at fin _f) for more than 1.5mm; Interval W between relative fin (12) ₂, the outstanding length W of protrusion tab (16) ₁with its ratio W ₁/ W ₂be 0.3 ~ 0.9.

Description

Heat-transfer pipe

Technical field

The present invention relates to a kind of for the heat-transfer pipe in the heat exchanger of such as refrigerator, air conditioner etc.

Background technology

The heat-transfer pipe be generally used in air conditioner and refrigerator etc. be make the refrigerant evaporation in pipe or condensing and with carry out heat exchange managing the outer fluid flowed, from the view point of high efficiency and the energy-saving of heat exchanger, inner face ditch is usually used to pay pipe (inner face Ditch pay pipe).

Pipe paid by this inner face ditch, and at pipe inner face, relative tubular axis, linearity or helically form trickle triangular cross-section or the ditch of trapezoidal cross-section.By arranging these ditches at pipe inner face, compare while smooth tubes can increase heat transfer area, the stirring action also by stirring cooling medium liquid improves heat transfer property.

In recent years, especially high performance and miniaturization are strongly required for heat exchanger for air conditioner, in addition, along with the amendment of energy conservation (law about the rationalization that the energy uses), require the high performance of heat-transfer pipe further.

Therefore, the inner face spiral goove is in the past paid on pipe (interior surface helix Ditch pays pipe), has carried out the improvement of ditch number, lead angle, ditch shape etc., but still cannot meet the performance of the demand.

Therefore, instead these in the past with the heat-transfer pipe of spiral heat dissipation sheet pipe, For example, Patent Document 1 discloses the heat-transfer pipe that a kind of sulcus of chiasm is paid, in order to promote the stirring action of cooling medium liquid, form the counter drain of tap drain and the segmentation fin degree of depth at pipe inner face.

The heat-transfer pipe that this sulcus of chiasm is paid, is provided with at pipe inner face and sees by the plane of counter drain segmentation fin the multiple three-dimensional projection (3) slightly becoming S word shape.

More specifically, three-dimensional projection (3), in its leading section, be provided with outstanding fin (3a), can guide along the refrigerant stream along tap drain to the direction of counter drain, simultaneously in rearward end, be provided with to the fin (3b) outstanding with this fin (3a) rightabout.

Describe following idea in patent document 1, the refrigerant flowed in tap drain to be led counter drain direction by fin (3a), thus, can obtain the stirring action that refrigerant Complex Flows produces, its result, can obtain pyroconductivity.

But, heat-transfer pipe in patent document 1, the fin (3a) had by three-dimensional projection (3), (3b), although the stirring near the pipe inner peripheral surface side that can realize refrigerant, but be not stirred in the refrigerant of the radial direction central side flowing of pipe, consequently, the transmission performance of above-mentioned requirements cannot be met.

Patent document 1: Unexamined Patent 8-178574 publication.

Summary of the invention

The object of the present invention is to provide a kind of increase that can suppress the pressure loss, and the heat-transfer pipe of pipe thermal conductivity can be improved.

The invention provides a kind of heat-transfer pipe, it is characterized in that, external diameter is less than 7mm, is formed have special angle β at the relative tube axial direction of pipe inner face ₁height H _ffor the screw-shaped radiator fins of 0.1mm ~ 0.30mm, at described pipe inner face, described fin is formed on direction by depth H at fin _nby the helical form counter drain of 0.1mm ~ 0.30mm is split, and form the outstanding multiple fin constituting portion of helical form at this pipe inner face; In at least hand of spiral downstream of described fin constituting portion, between the described fin that described tube axial direction upstream side is adjacent, there is outstanding protrusion tab; The relatively described fin of this protrusion tab has angle α, 5 °≤α < 70 °; The structure of described fin constituting portion comprises: form the interval P between the fin constituting portion on direction at described fin _ffor more than 1.5mm; Interval W between relative fin ₂, described protrusion tab outstanding length W ₁with its ratio W ₁/ W ₂be 0.3 ~ 0.9.

In right of the present invention and description, the numerical value recorded after the numerical value recorded before the scope using symbol " ~ " to carry out recording comprises symbol and symbol.

The formation of described heat-transfer pipe is described above, fin height (H _f) in the scope of 0.1mm ~ 0.30mm, especially at least hand of spiral downstream of the described fin constituting portion of more than 0.1mm, between the described fin that tube axial direction upstream side is adjacent, there is relative fin and form the protrusion tab given prominence to the angle of more than 5 ° in direction.

By this formation, the part refrigerant flowed between described fin, collides with described protrusion tab, holds together on inside pipe radial direction, effectively can produce three-dimensional nonstationary flow thus.In addition, the collision to protrusion tab makes refrigerant be detained, and because the thickness of liquid film of the refrigerant flowed in tap drain forms heterogeneity on direction at fin, the part that therefore thickness of liquid film is thin can improve heat-conductive characteristic

Therefore, compare the existing heat-transfer pipe solely forming sulcus of chiasm at pipe inner peripheral surface, the filming of sinuous flow promotion and the liquid cooling matchmaker contained inside pipe radial direction can be realized, desirable pyroconductivity can be obtained.

In addition, the counter drain degree of depth (H _n) within the scope of 0.1mm ~ 0.30mm, especially at more than 0.1mm, protrusion tab and tap drain angulation (α) are less than 70 °, such that the refrigerant that flows between described fin is easier to be flowed into counter drain, therefore, the refrigerant that can realize all pipe inner peripheral surfaces crossing fin stirs.Therefore, desirable sinuous flow facilitation effect can be obtained, and the increase of the pressure loss can be prevented.

In addition, fin height (H _f) within the scope of 0.1mm ~ 0.30mm, be especially 0.25mm, the internal diameter of small diameter tube can not be too small, can suppress the increase of the pressure loss.

In addition, the interval (P between the fin constituting portion on direction is formed at described fin _f) be more than 1.5mm, excessively can not hinder the flowing of the refrigerant along fin thus, the refrigerant stirring action because abundant revolving force reaches can be obtained.In addition, the fin intensity that can guarantee when bearing mechanical expander.

In addition, outstanding length (W ₁) ratio (W ₁/ W ₂) in 0.3 ~ 0.9 scope, be especially preferably W ₁/ W ₂=0.4 ~ 0.9.Specifically, external diameter is less than in the small diameter tube of 7mm, because the restriction in above-mentioned pressure loss problem and processing causes fin height (H _f) lower, therefore in order to obtain fully because of protrusion tab refrigerant on to hold together and to the guide effect of counter drain, the outstanding length (W between needing the fin to protrusion tab ₁) ratio (W ₁/ W ₂) be set to more than 0.4.

In addition, when being set to below 0.9, not hindering the supply to the liquid film between fin when evaporating, therefore can prevent the reduction of the heat of evaporation conductivity caused owing to drying up.In addition, external diameter is less than to the increase and decrease of the pressure loss in the small diameter tube of 7mm, by fin height (H _f) and lead angle (β ₂) and fin constituting portion between interval (P _f) arranged, and outstanding length (W ₁) impact less, even therefore above-mentioned formation also exceedingly can not increase the pressure loss, obtain above-mentioned heat transfer facilitation effect.

As the condensing heat-transfer pipe of mode of the present invention, its structure is as follows: described fin height H _f> 0.12mm; Described counter drain depth H _n> 0.12mm; The described protrusion tab angle [alpha] of relative fin is more than 20 °; The counter drain angle beta of relatively described tube axial direction ₂for-10 ° ~ 15 °; The interval P between the fin constituting portion on direction is formed at described fin _fbe 2 ~ 5mm; The counter drain width W on direction is formed at this fin ₃for more than 0.1mm.

Described condensing heat-transfer pipe, by fin height (H _f) the condensing pipe that is greater than 0.12mm suitably forms.That is, by making fin constituting portion uprise, and then can prevent the performance caused because all heat-transfer areas are buried by condensing water from reducing.

In addition, if make the counter drain degree of depth (H _n) be greater than 0.12mm, the lead angle (β of counter drain ₂) be-10 ~ 15 °, the width (W of counter drain ₃) be more than 0.1mm, then by guaranteeing the stream sectional area increasing counter drain, the lead angle (β of the counter drain that diminishes ₂) and promote the discharge effect to the condensing water of tube axial direction, make pipe end face keep dry state and improve condensing performance.

In addition, if protrusion tab and tap drain angulation (α) they are more than 20 °, the interval (P between fin constituting portion _f) be below 5mm, then the refrigerant fluid capacitance flowed between fin easily and protrusion tab collide, larger refrigerant stirring action can be obtained.

In addition, as the evaporation heat-transfer pipe of mode of the present invention, its structure is as follows: described fin height H _ffor more than 0.1mm; Described counter drain depth H _nfor more than 0.1mm; The described protrusion tab angle [alpha] of relative fin is less than 20 °; The counter drain angle beta of relatively described tube axial direction ₂it is more than 10 °; The interval P between the fin constituting portion on direction is formed at described fin _ffor more than 5mm.

Described evaporation heat-transfer pipe, by fin height (H _f) suitably form for the evaporation tube of more than 0.10mm.That is, while increasing effective heat transfer area of pipe inner face fully, make the thinning of liquid film of fin near top, thus improve volatility.

In addition, if the counter drain degree of depth (H _n) for more than 0.10mm, protrusion tab and tap drain angulation (α) are less than 20 °, the refrigerant then flowed between fin easily flows into counter drain, therefore owing to crossing the expansion of the refrigerant of fin, and the increase of wetted area and obtain evaporating facilitation effect.In addition, the increase of the pressure loss can be prevented to the increase of the cold medium flux of tube axial direction.

In addition, if the interval (P between fin constituting portion _f) be more than 5mm, then can not excessively hinder refrigerant stream that the pressure loss can be suppressed to increase.

In addition, the lead angle (β of the counter drain of relative tubular axis ₂) when being the wide-angle of more than 10 °, liquid in pipe can be possessed so that repeated evaporation longlyer, and its result is for improving pyroconductivity.

By the present invention, when carrying out heat exchange by heat-transfer pipe, the increase of the pressure loss can be suppressed, and pipe thermal conductivity can be improved.

Accompanying drawing explanation

Fig. 1 is the partial enlargement open cube display of the heat-transfer pipe representing present embodiment.

Fig. 2 is the expansion plane of the pipe inner face representing the fin constituting portion had in the heat-transfer pipe of Fig. 1.

Fig. 3 is the partial enlargement open cube display of other examples representing heat-transfer pipe of the present invention.

Fig. 4 is the expansion plane of the pipe inner face representing the fin constituting portion had in the heat-transfer pipe of Fig. 3.

The skeleton diagram of the experimental provision that the performance evaluation that Fig. 5 is the heat-transfer pipe representing present embodiment uses.

Fig. 6 is the expansion plane of the pipe inner face representing the fin constituting portion had in other examples of heat-transfer pipe of the present invention.

Detailed description of the invention

In conjunction with accompanying drawing below, one embodiment of the present invention is described.

Heat-transfer pipe 11 in present embodiment as shown in Figure 1 and Figure 2, pipe inner face 10 forms spiral helicine fin 12.

In addition, the heat-transfer pipe 11 in present embodiment, has tap drain 13 by forming spiral helicine fin 12 on pipe inner face 10 between fin 12.

And then described heat-transfer pipe 11, by by described fin 12, forms multiple fin constituting portion 12A in the upper cut-out of the tap drain hand of spiral D2 (fin formation direction) of this fin 12.

In addition, heat-transfer pipe 11 in present embodiment, owing to forming the outstanding protrusion tab 16 of helical form towards counter drain hand of spiral D3 on pipe inner face 10, and between the fin constituting portion 12A of tap drain hand of spiral D2, there is the counter drain forming section 15 cutting off fin 12 because of counter drain 14.

Fig. 1 is the partial enlargement open cube display of the pipe inner face 10 of the heat-transfer pipe 11 schematically showing present embodiment, and Fig. 2 is the expansion plane near fin constituting portion 12A.Further, in Fig. 2, the top of described fin constituting portion 12A, described protrusion tab 16 is only schematically shown.

Further, described fin constituting portion 12A, at tap drain hand of spiral downstream D2d, has the protrusion tab 16 (first protrusion tab 16a) outstanding to the described tap drain 13 of tube axial direction upstream side D1u.

The external diameter of described heat-transfer pipe 11 is the 5mm be less than within the scope of 7mm.

Height (the H of described fin 12 _f) be the 0.15mm within the scope of 0.1mm ~ 0.30mm.

The degree of depth (the H of described counter drain 14 _n) be the 0.15mm within the scope of 0.1mm ~ 0.30mm.

The angle (α) of the relatively described fin 12 of described protrusion tab 16 is 34 ° within the scope of 5 °≤α < 70 °.

Described fin constituting portion 12A forms the interval (P between the fin constituting portion on direction at fin _f) be the 2.4mm in more than 1.5mm scope.

More specifically, the screw-shaped radiator fins 12 in the heat-transfer pipe 11 of present embodiment, relative tube axial direction D1 is 40 ° of angle (β ₁).Further, the fin count in each pipe week is 56, fin height (H _f) be 0.15mm, the section shape of fin 12 becomes roughly trapezoidal shape.

Counter drain 14 is formed along counter drain hand of spiral D3, and relative tube axial direction D1 is 6 ° of angle (β ₂).Further, section is inverted triangle shape, forms the counter drain width (W on direction at fin ₃) be 0.15mm.

Hn in Fig. 1 represents the mean depth (Hn) from counter drain hand of spiral upstream side D3u to the counter drain 14 of counter drain hand of spiral downstream D3d.

In addition, protrusion tab 16 is to the outstanding length (W of described tap drain 13 ₁) width (W of relatively described tap drain 13 ₂), be the ratio (W of 0.5 ₁/ W ₂).

Further, described fin constituting portion 12A, at tap drain hand of spiral downstream D2d, has the protrusion tab 16 (second protrusion tab 16b) outstanding to the described tap drain 13 of tube axial direction downstream D1d.

On the other hand, described fin constituting portion 12A, at tap drain hand of spiral upstream side D2u, there is the protrusion tab 16 (three protrusion tab 16c) respectively outstanding to the described tap drain 13 of tube axial direction upstream side D1u, and the protrusion tab 16 (four protrusion tab 16d) outstanding to the described tap drain 13 of tube axial direction downstream D1d.

Therefore, as shown in Figure 2, fin constituting portion 12A, in the H letter shapes (apsacline H-shaped shape) tilted viewed from plane.

Above-mentioned heat-transfer pipe 11 can obtain the effect of the following stated.

The heat-transfer pipe 11 of present embodiment, as mentioned above, at least tap drain hand of spiral downstream D2d of described fin constituting portion 12A, has to the outstanding described first protrusion tab 16a of the described tap drain 13 of tube axial direction upstream side D1u.

Therefore, the part refrigerant of flowing in described tap drain 13, collides with described first protrusion tab 16a, understands on inside pipe radial direction, therefore can produce three-dimensional nonstationary flow.

Therefore, sinuous flow facilitation effect contained inside the radial direction of pipe can be obtained, compare and solely form the existing heat-transfer pipe of sulcus of chiasm at pipe inner face or there is the existing heat-transfer pipe of fin near counter drain, better pyroconductivity can be realized.

Further, above-mentioned spiral helicine described fin 12, especially at least tap drain hand of spiral upstream side D2u of described fin constituting portion 12A, have to the 3rd outstanding protrusion tab 16c of tap drain 13 side of tube axial direction upstream side D1u, therefore in described tap drain 13, the refrigerant of flowing is more prone to flow into described counter drain 14, produce secondary flow thus, especially while the mixing effect obtaining the refrigerant near pipe inner peripheral surface, the increase of the pressure loss can be prevented.

In addition, the heat-transfer pipe 11 of present embodiment, is set to the angle (α) that tap drain 13 relatively described above is 34 ° by described protrusion tab 16.

Therefore, excessively can not hinder the refrigerant stream of flowing in described tap drain 13, and its part can be made to collide with described protrusion tab 16 and from tap drain 13, flow to counter drain 14, therefore, improve pyroconductivity by larger refrigerant stirring action.

Further, because the cold medium flux to tube axial direction D1 increases, the increase of the pressure loss can therefore be prevented.

In addition, the heat-transfer pipe 11 of present embodiment, forms the interval (P between the fin constituting portion on direction as mentioned above at fin _f) be 2.4mm, while obtaining sufficient refrigerant stirring action, fin intensity when can bear mechanical expander can be obtained.

In addition, the heat-transfer pipe 11 of present embodiment, as mentioned above, protrusion tab 16 is to the outstanding length (W of described tap drain 13 ₁) width (W of relatively described tap drain 13 ₂) be 0.5 ratio (W ₁/ W ₂), can promote thus to hold together on the refrigerant inside radial direction, and obtain desirable refrigerant stirring action, its result is for improving pyroconductivity.

In addition, the degree of depth (H of described counter drain 14 _n), as the heat-transfer pipe 11 of present embodiment, preferably with more than 0.1mm and be 40 ~ 100% of tap drain 13 degree of depth.

Make the degree of depth of counter drain 14 be more than 0.1mm, and be more than 40% of tap drain 13 degree of depth, thus make the refrigerant of flowing in tap drain 13 easily flow into counter drain 14, while obtaining desirable pyroconductivity, the increase of the pressure loss can also be prevented.

On the other hand, make the degree of depth of counter drain 14 be less than 100% of tap drain 13 degree of depth, thus on pipe meat is thick, do not form the incision darker than the tap drain degree of depth, therefore can the quality (specification that end meat is thick) of holding tube.

Above, describe the heat-transfer pipe 11 of one embodiment of the present invention in detail, below, the experiment carried out for checking the performance of heat-transfer pipe 11 of the present invention is described.

In this experiment, made nine types of embodiment 1 to 9 as heat-transfer pipe of the present invention, the heat-transfer pipe simultaneously used as comparison other has made the Four types of comparative example 1 to 4.

The heat-transfer pipe of embodiment 1 to 9, is made into the shape with external diameter as shown in table 1, fin, counter drain, protrusion tab respectively.

[table 1]

At this, the heat-transfer pipe of embodiment 2, can learn from the shape in each portion as shown in table 1, uses the heat-transfer pipe with heat-transfer pipe 11 same shape of aforementioned embodiments.

In addition, the heat-transfer pipe of embodiment 1,2,8,9, all has the multiple divided fin constituting portion 12A that plane regards apsacline H-shaped shape as.On the other hand, the heat-transfer pipe 21 of embodiment 3 to 7 as shown in Figures 3 and 4, has the multiple fin constituting portion 42A becoming J-shaped shape (plane sees J-shaped shape) when plane is seen.

More specifically, in the heat-transfer pipe 21 of embodiment 3 to 7, plane regards the divided fin constituting portion 42A of J-shaped shape as, on this fin constituting portion 42A on the basis with the first protrusion tab 16a, also there is the second protrusion tab 16b and the 3rd protrusion tab 16c.

At this, Fig. 3 is the partial enlargement open cube display of pipe inner face 10 appearance of the heat-transfer pipe 21 schematically showing embodiment 3 to 7, and Fig. 4 is the expansion plane after the segmentation of the pipe inner face 10 of the heat-transfer pipe 21 of embodiment 3 to 7 near fin.Further, the top of described fin constituting portion 42A, described protrusion tab 16 is only schematically shown in Fig. 4.

Further, about comparative example, comparative example 1 to 3 has the heat-transfer pipe that plane regards the fin constituting portion of apsacline H-shaped shape as, and comparative example 4 has the heat-transfer pipe that plane regards the fin constituting portion of J-shaped shape as.

This experiment, be use condensing property detecting device 50A in the pipe shown in Fig. 5 (a) to carry out verifying heat-transfer pipe pipe in the condensing experiment of condensing performance, use the in-tube evaporation property detecting device (50B) shown in Fig. 5 (b) to carry out verifying the evaporation experiment of volatility simultaneously.

And, Fig. 5 (a), (b) represent the skeleton diagram of condensing property detecting device 50A, in-tube evaporation property detecting device 50B in pipe respectively, any device 50A, the 50B air conditioner all with general is identical, and entirety is consisted of freeze cycle.

Specifically, in condensing experiment, prepare the heat-transfer pipe of embodiment 1 to 9, comparative example 1 to 4, fin is formed respectively at the pipe inner face of heat-transfer pipe, but on this fin, do not form the heat-transfer pipe of counter drain (fin forming portion), namely existing inner face spiral goove pays pipe, as shown in Fig. 5 (a), assembles developmental tube 44 in condensed device.

Obtain the pyroconductivity (α of the heat-transfer pipe of embodiment 1 to 9 now and comparative example 1 to 4 _i) and only there is the pyroconductivity (α of heat-transfer pipe of tap drain of same shape respectively _bASE) ratio (α _i/ α _bASE), thus, verify the effect of condensing performance of the present invention.In addition, for pressure loss ratio (Δ P/ Δ P _bASE) also adopt identical comparison.

In evaporation experiment, prepare the heat-transfer pipe of embodiment 1 to 9, comparative example 1 to 4, the pipe inner face of heat-transfer pipe respectively forms fin, but on this fin, do not form the heat-transfer pipe of counter drain (fin forming portion), namely existing inner face spiral goove pays pipe, as shown in Fig. 5 (b), in evaporimeter, assemble developmental tube 44.

Pyroconductivity (the α of the embodiment 1 to 9 when obtaining secondary and the heat-transfer pipe of comparative example 1 to 4 _i) and only there is the pyroconductivity (α of heat-transfer pipe of tap drain of same shape respectively _bASE) ratio (α _i/ α _bASE), thus, verify the effect of volatility of the present invention.In addition, for pressure loss ratio (Δ P/ Δ P _bASE) also adopt identical comparison.

As shown in Fig. 5 (a), (b), test section in pipe in condensing property detecting device 50A, in-tube evaporation property detecting device 50B is made up of Double-wall-tube heat exchanger, refrigerant flows in developmental tube 44, forming the inside of annulus 45 of outside housing, making the water of this refrigerant stream and the heat exchange to the flowing to phase direction (hereinafter referred to as " heat exchange water ".) carry out heat exchange, the effective length of this developmental tube 44 is set as 2m.

Further, as the heat exchange water in condensing experiment, flowing be water at low temperature; As the heat exchange water in evaporation experiment, flowing be high-temperature water.

In addition, as shown in Fig. 5 (a), (b), each privileged site of test section arranges thermometer, pressure gauge and flowmeter.Further, in Fig. 5 (a), (b), T represents thermometer, and P represents pressure gauge, and G represents flowmeter.

Then, as the refrigerant inlet of developmental tube 44 and the experiment condition of outlet, the refrigerant inlet degree of superheat in condensing experiment, refrigerant exit degree of subcooling, the setting of the refrigerant inlet aridity in evaporation experiment, the refrigerant exit degree of superheat is as shown in table 2 respectively.

[table 2]

Experiment condition in these condensing experiments, evaporation experiment, in order to all identical with the heat exchanger entrance condition of air conditioner, measures after adjustment water temperature.

In addition, the average saturation temperature of refrigerant of the entrance and exit of developmental tube 44 is as shown in table 2, is set as that, while 48 DEG C, evaporation experiment is set as 5 DEG C in condensing experiment.

In refrigerant, CFC is replaced to use R410A, this R410A is mixing refrigerant, therefore the refrigerant being arranged on compressor outlet portion is used to take portion's (Fig. 5 (a), (b) reference) refrigerant of taking in an experiment, by testing while gas chromatograph for determination refrigerant ratio of components.

Further, the analysis result of gas chromatograph, is reflected in t described later by calculating _s1と t _s2in.

Represent the pressure loss (Δ P, the Δ P in the pipe of the developmental tube 44 of condensing performance, volatility _bASE) and pyroconductivity (α _i, α _bASE) try to achieve as described below.

First the pressure loss in pipe is by the entrance of developmental tube 44, the pressure differential of outlet and trying to achieve.

Pyroconductivity in pipe calculates to formula (4) according to the measured value through type (1) of this experiment.

[formula 1]

α_{i} = \frac{1}{\frac{A \cdot t_{m}}{Q} - \frac{1}{α_{o}}}

[formula 2] Q=GC _p| t _w1-t _w2|

When [formula 3] is condensing

t_{m} = \frac{(t_{s 1} - t_{w 2}) - (t_{s 2} - t_{w 1})}{\ln \frac{t_{s 1} - t_{w 2}}{t_{s 2} - t_{w 1}}}

During evaporation

t_{m} = \frac{(t_{w 1} - t_{s 2}) - (t_{w 2} - t_{s 1})}{\ln \frac{t_{w 1} - t_{s 2}}{t_{w 2} - t_{s 1}}}

[formula 4]

α_{o} = 0.02 \cdot (k / De) \cdot {(D / d)}^{0.53} \cdot {Re}^{0.8} \cdot \Pr^{1/3}

At this, the Q in formula (1) represents heat-shift (kW), and A represents developmental tube external surface area (m ²), t _mrepresent logarithmic mean temperature (K), α _orepresent the outer pyroconductivity (kW/m of pipe ²k).

G in formula (2) represents the flow (kg/s) of heat exchange water, C _prepresent that heat exchange is with specific heat of water (kJ/kgK), t _w1represent the inlet temperature (K) of heat exchange water, t _w2represent the outlet temperature (K) of heat exchange water.

T in formula (3) _s1represent refrigerant inlet saturation temperature (K), t _s2represent refrigerant exit saturation temperature (K).

K in formula (4) represents the pyroconductivity (kW/mK) of heat exchange water, D _erepresent annulus equivalent diameter (m).D represents housing inner diameter (m), and d represents developmental tube external diameter (m), R _erepresent the Reynolds number of heat exchange water, P _rrepresent the Prandtl number of heat exchange water.

That is, calculate Q according to the measured value of temperature etc., parameter preset through type (2), when through type (3) calculates condensing, evaporation time t _m, through type (4) calculates α _o, the value these calculated substitutes into formula (1) can calculate pipe thermal conductivity thus.

The condensing performance obtained like this and the evaluation result of volatility as shown in table 3.

[table 3]

Known by table 3, about pyroconductivity, in any heat-transfer pipe of embodiment 1 to 9, condensing performance and volatility all indicate the heat-conductive characteristic paying Guan Genggao than existing spiral goove.

Thus, can confirm that a part of refrigerant flowed in described tap drain particularly collides with the first protrusion tab, hold together on inside pipe radial direction and produce the significant sinuous flow had inside pipe radial direction and promote and the effect of filming of liquid cooling matchmaker; And at a part of refrigerant that described tap drain flows, by flowing into described counter drain and to the refrigerant diffusion effect of pipe inner peripheral surface entirety.

In addition, according to the result of embodiment 1 and comparative example 2, improve the performance need counter drain degree of depth (H _n) be more than 0.1mm, and, by the comparison of embodiment 1,2,3, improve the condensing performance need counter drain degree of depth (H _n) being greater than 0.12mm, the degree of depth more can improve thermal conductivity ratio more deeply.This is because during counter drain depth as shallow, the influx deficiency to the counter drain of refrigerant causes.

In addition, according to the result of embodiment 1,5,7,8,9 and comparative example 1, during condensing and evaporation, fin forms the interval (P between the fin constituting portion in direction _f) can thermal conductivity ratio be improved when more than 1.5mm, near 4mm, reach peak value.On the other hand, about pressure loss ratio, the interval (P between fin constituting portion _f) larger, more reduce.

Especially about embodiment 8,9, evaporating pressure loss, than being less than 100, plays the pipe of performance advantage when this pipe can be described as the evaporation tube as pressure loss attention and uses.This is because the interval (P between fin constituting portion _f) large, and the differential seat angle of tap drain and protrusion tab (α) is 10 ° less, refrigerant easily flows into counter drain thus, and the cold medium flux to tube axial direction increases.

In addition, by the result of embodiment 1 and comparative example 3, when known tap drain and protrusion tab angulation (α) are more than 70 °, the pressure loss can sharply increase.This is that therefore in order to suppress the increase of the pressure loss, and improve pyroconductivity, the differential seat angle (α) of preferred tap drain and protrusion tab is less than 70 ° because the refrigerant of flowing middle in tap drain needs significantly to change in direction inflow counter drain.

By the result of embodiment 5,6 and comparative example 4, the width (W of the tap drain 13 of known relative protrusion tab ₂) outstanding length (W ₁) ratio (W ₁/ W ₂) raising of larger thermal conductivity ratio is larger, W ₁/ W ₂effect by arranging protrusion tab when=0.2 does not almost have.

The raising of pyroconductivity can be found out in embodiment 1, in order to obtain sufficient effect, outstanding length (W ₁) ratio need more than 0.3, in addition, about pressure loss ratio, even if outstanding length (W ₁) elongatedly also correspondingly not increase, therefore can confirm preferably external diameter will be given prominence to length (W less than in the small diameter tube of 7mm ₁) setting change greatly.

By the comparison of embodiment 4,6, the lead angle (β of counter drain can be confirmed ₂) larger, the differential seat angle (α) of tap drain and protrusion tab is less, can be improved heat of evaporation conductivity better.

This is because embodiment 8,9 is according to the interval (P between fin constituting portion _f) size, the raising of heat of evaporation conduction ratio is remarkable, because of larger counter drain lead angle (β ₂) the possessing of liquid of causing, expand with the liquid film crossing fin caused because tap drain and the differential seat angle of protrusion tab are less and all promote relevant with evaporation.

In addition, the invention is not restricted to the heat-transfer pipe of above-described embodiment 1 to 9, can by various mode, pattern and forming.

Such as, heat-transfer pipe of the present invention, on described fin constituting portion 12A, 42A, at least has the first protrusion tab 16a, as the heat-transfer pipe 11 of above-mentioned embodiment (embodiment 1,2,8,9), or the heat-transfer pipe 21 of embodiment 3 to 7.

Like this, by having described first protrusion tab 16a, part refrigerant and the described first protrusion tab 16a of flowing in tap drain 13 collide, and hold together on pipe radial direction, produce three-dimensional nonstationary flow, realize the raising of pyroconductivity because further sinuous flow promotes.

Specifically, heat-transfer pipe of the present invention such as, as shown in Figure 6, can be have the heat-transfer pipe 31 that plane is seen as multiple fin constituting portion 52A of the zigzag shape (plane sees the Z-shaped shape of apsacline) of inclination.

In addition, Fig. 6 has the expansion plane that plane sees the pipe inner face of the fin constituting portion 52A of Z-shaped shape.But in Fig. 6, only schematically illustrate the top of described fin constituting portion 52A, described protrusion tab 16.

Plane sees the divided fin constituting portion 52A of Z-shaped shape, and the basis of this fin constituting portion 52A also has the first protrusion tab 16a and the 4th protrusion tab 16d.

And, described heat-transfer pipe 31, make refrigerant to flow on the contrary with upstream side and the downstream direction as shown in Figure 6 of tube axial direction D1,4th protrusion tab 16d at the tap drain hand of spiral downstream D2d of described fin constituting portion 52A, and to the described tap drain 13 of tube axial direction upstream side D1u outstanding (with reference to arrow shown in figure 6 brace).

Namely, the heat-transfer pipe 31 of above-mentioned formation, in pipe, using any side of tube axial direction D1 side and opposite side as upstream, side makes refrigerant move to downstream effluent, the any one party of the first protrusion tab 16a, the 4th protrusion tab 16d must on the tap drain hand of spiral downstream D2d of described fin constituting portion 52A, and outstanding to the described tap drain 13 of tube axial direction upstream side D1u.

Therefore, the heat-transfer pipe of described formation, has nothing to do with the installation direction of heat exchanger, all can guarantee above-mentioned excellent properties, can not consider installation direction and easily install heat exchanger.

The present invention can be consisted of above-mentioned present embodiment, but is not limited to above-mentioned formation, can use numerous embodiments.

Further, above-mentioned embodiment and with formation of the present invention corresponding in, the corresponding fin interval of the present invention of tap drain 13 of this embodiment.

Industry utilizes possibility

The present invention can use as the heat-transfer pipe be arranged in the heat exchanger of refrigerator, air conditioner etc.

Symbol description

10 ... pipe inner face

11,21,31 ... heat-transfer pipe

12,42,52 ... fin

12A, 42A, 52A ... backing constituting portion

13 ... tap drain

14 ... counter drain

15 ... counter drain forming section

16 ... protrusion tab

D1 ... tube axial direction

D2 ... the tap drain hand of spiral

D3 ... the counter drain hand of spiral

Claims

1. a heat-transfer pipe, is characterized in that, external diameter is less than 7mm, is formed have special angle β at the relative tube axial direction of pipe inner face ₁height H _ffor the screw-shaped radiator fins of 0.1mm ~ 0.30mm, by forming spiral helicine fin on described pipe inner face, there is between described fin tap drain;

At described pipe inner face, described fin is formed on direction by depth H at fin _nby the helical form counter drain of 0.1mm ~ 0.30mm is split, and form the outstanding multiple fin constituting portion of helical form at this pipe inner face;

In at least hand of spiral downstream of described fin constituting portion, between the described fin that described tube axial direction upstream side is adjacent, there is outstanding protrusion tab; The relatively described fin of this protrusion tab has angle α, 5 °≤α < 70 °;

The structure of described fin constituting portion comprises: form the interval P between the fin constituting portion on direction at described fin _ffor more than 1.5mm; Interval W between relative fin ₂, described protrusion tab is to the outstanding length W of described tap drain ₁with its ratio W ₁/ W ₂be 0.3 ~ 0.9.

2. heat-transfer pipe as claimed in claim 1, forms condensing heat-transfer pipe with following structure, wherein, and described fin height H _f> 0.12mm; Described counter drain depth H _n> 0.12mm; The described protrusion tab angle [alpha] of relative fin is more than 20 °; The counter drain angle beta of relatively described tube axial direction ₂for-10 ° ~ 15 °; The interval P between the fin constituting portion on direction is formed at described fin _fbe 2 ~ 5mm; The counter drain width W on direction is formed at this fin ₃for more than 0.1mm.

3. heat-transfer pipe as claimed in claim 1, form evaporation heat-transfer pipe with following structure, wherein, the described protrusion tab angle [alpha] of relative fin is less than 20 °; The counter drain angle beta of relatively described tube axial direction ₂it is more than 10 °; The interval P between the fin constituting portion on direction is formed at described fin _ffor more than 5mm.