Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
  • F28D2021/0068—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for refrigerant cycles
  • F28D2021/007—Condensers

Definitions

• the present invention relates to a heat transfer tube with an inner groove used for a heat exchanger, and more particularly to a specific structure of an inner groove.
• a heat transfer tube having an inner surface provided with a number of spiral grooves is used as a heat exchanger used as an evaporator or a condenser in a refrigerating device such as an air conditioner.
• the heat transfer tube with internal grooves has a spiral heat groove to increase the heat transfer area and increase the heat transfer performance by allowing the refrigerant in the tube to flow evenly into a thin film. is there.
• this heat transfer tube with internal grooves is used for a condenser
• the refrigerant progresses from the inlet side to the outlet side as the refrigerant progresses in the tube, the refrigerant forms an annular flow and flows along the inner surface of the tube. Since the thickness of the liquid refrigerant layer becomes thicker toward the downstream side, the thermal resistance increases and the condensation performance decreases.
• the applicant of the present application has proposed a heat transfer tube with an inner surface groove that can suppress the deterioration of the condensation performance, the groove on the inner surface of the tube, the main groove of the first lead angle, and the second lead angle different from the first lead angle.
• the refrigerant flows along the main groove to form a thin liquid film, and when the liquid refrigerant reaches the deformed portion, the liquid refrigerant collides with the side surface of the groove of the deformed portion to form a heat transfer tube.
• There has been proposed one that is scattered toward the center see Japanese Patent Application Laid-Open No. H10-153630). According to this configuration, it is difficult to form a thick layer of the liquid refrigerant on the inner surface of the heat transfer tube, so that the liquefaction of the gas refrigerant is promoted.
• the present invention has been made in view of such a problem, and an object of the present invention is to specify a specific configuration of a main groove and a deformed portion of a groove in a heat transfer tube having an inner surface groove. Thus, more stable heat exchange performance can be obtained. Disclosure of the invention
• the first to 12th solutions of the present invention are as follows.
• a plurality of grooves (11) are formed on the inner peripheral surface, and the grooves (11) are formed at a first lead angle (h).
• the main groove (12) formed and the deformed portion (13) formed at the second lead angle (?) Different from the first lead angle (h) are continuously formed,
• the main groove (12) and the deformed portion (13) of the groove (11) are set in a predetermined relationship specified below.
• the first solution taken by the present invention is that, in the above-described premise, the ratio of the length of the deformed portion (13) to the length of one cycle of the groove (11) is determined. It is set within the range of 10% to 35%.
• the second solution is that in the above-described configuration, the length of one deformed portion (13) is set within a range of 5 to 15 times the pitch of the groove (11). It is.
• the third solution is that, in the above-described configuration, the five to fifteen deformed parts (13) are arranged to intersect the extension of the one main groove (12). Things.
• a fourth solution is that, in the electric resistance welded tube having the above-mentioned premise, the joint portion (14) and the deformed portion (13) of the electric resistance welded tube are formed so that the circumferential direction of the electric resistance welded tube is substantially equal. Place at the position It was done.
• the term “electrically welded pipe” generally means a pipe in which a long strip-shaped material is joined by electric resistance welding.However, in this specification, the joining method is not limited, and the joining is performed along the longitudinal direction. It shall be used in a broad sense including all tubes.
• a fifth solution is that in the first to fourth solutions described above, the deformed portion (13) is formed at a plurality of locations within one cycle of the groove (11). .
• the sixth solution is that, in each of the first to fourth solutions, one of the first lead angle (h) and the second lead angle (?) Is set with respect to the pipe axis direction. Set one twist angle in the range of 5 ° to 30 ° and set the other of the first lead angle (h) and the second lead angle (?) In the other torsion direction with respect to the pipe axis line. It is set within the range of 5 ° to 30 °.
• a seventh solution is the sixth solution, wherein the main groove (12) of the groove (11) and the deformed portion (13) are oriented symmetrically with respect to the pipe axis direction.
• 1 Lead angle (H) and 2nd lead angle (?) Are set.
• An eighth solution is to specify the first lead angle (h) and the second lead angle (?) In the seventh solution, and these angles (h) and (?) Are defined as follows. Each was set at 18 ° in the opposite direction across the pipe axis direction line.
• a ninth solution is that, in the first to fourth solutions, the ridge (15) constituting the main groove (12) is provided with a secondary groove (21) formed by a plurality of intermittent concave portions. 16).
• a tenth solution is the ninth solution according to the ninth solution, wherein the secondary groove (16) is provided with a ridge (15) of the main groove (12) so as to be separated from the deformed portion (13) by a predetermined distance. ) Is located at the center.
• the eleventh solution is the ninth solution described above, wherein the secondary groove (16) is formed at a depth of 0.25 to 0.75 times the groove depth of the groove (11). It is to be formed.
• a twelfth solution is the ninth solution, wherein the secondary groove (16) is formed substantially along the pipe axis direction line.
• the thirteenth to fifteenth solutions according to the present invention have a plurality of grooves (11) formed on the inner peripheral surface, as in each of the above solutions, and the grooves (11) are The main groove (12) formed at the first lead angle (h) and the deformed portion (13) formed at the second lead angle (?) Different from the first lead angle (h) are continuously formed. It is assumed that the heat transfer tube with internal grooves formed is used.
• a thirteenth solution is to provide a secondary groove (16) constituted by a plurality of intermittent concave portions on a ridge (15) constituting a main groove (12). ) Are arranged at the center of the ridge (15) of the main groove (12) at a predetermined distance from the deformed portion (13). Further, a fourteenth solution is to provide a secondary groove (16) constituted by a plurality of intermittent concave portions on a ridge (15) constituting a main groove (12). Is formed at a depth of 0.25 to 0.75 times the groove depth of the groove (11).
• a fifteenth solution is to provide a secondary groove (16) constituted by a plurality of intermittent concave portions on a ridge (15) constituting a main groove (12), ) Is formed substantially along the pipe axis direction line.
• the refrigerant condenses from the gas phase in the heat transfer tube, forms a thin liquid film, flows through the groove (11), and has a deformed portion.
• (1 3) is reached, the first lead angle (h) of the main groove (12) and the second lead angle (5) of the deformed portion (13) are different, so that they collide with the side surface of the deformed portion (13). Scatters toward the center of the heat transfer tube (10). Therefore, it is difficult to form a thick liquid layer on the inner surface of the heat transfer tube (10), and the generation of an annular flow is suppressed.
• the ratio of the length of the deformed portion (13) is set so as to be in the range of 10% to 35% with respect to the length of one cycle of the groove (11). You have set. For this reason, if it is smaller than 10%, even if the deformed portion (13) is provided, the liquid refrigerant is hardly scattered, but sufficient scattering action can be obtained, and if it is larger than 35%, it is used particularly for evaporators. At this time, the pressure loss is increased, but the pressure loss can be suppressed.
• the length of one deformed portion (13) is determined by the pitch of the groove (11). It is set in the range of 5 to 15 times. For this reason, the liquid refrigerant flowing in the main groove (12) of the groove (11) travels over the plurality of deformed portions (13), and at that time, the liquid refrigerant is sufficiently scattered. If the above value is smaller than 5 times, even if the deformed portion (13) is provided, the liquid coolant is hardly scattered, but sufficient scattering action can be obtained. When used in a vessel, the pressure loss is increased, but the pressure loss can be suppressed.
• the liquid coolant flowing through the main groove (12) is sufficiently scattered when going over a plurality of (5 to 15) deformed portions (13).
• pressure loss can be suppressed when used in an evaporator, while ensuring the scattering effect when used in a condenser.
• the joint (14) and the deformed part (13) of the ERW pipe are arranged at positions where the circumferential direction of the ERW pipe is substantially equally divided. Therefore, the liquid refrigerant flowing through the main groove (12) of the groove (11) is uniformly scattered in the heat transfer tube (10) at the joint (14) and the deformed portion (13) of the ERW tube. In this manner, the liquid refrigerant can be scattered over the entire inner surface of the heat transfer tube (10), and the deformed portion (13) and the joint portion (14) are dispersed and arranged. Pressure loss when used for
• each of the first to fourth solving means when the deformed portion (13) is formed at a plurality of locations within one cycle of the groove (11) as in the fifth solving means, the deformed portion (13 ), The scattering effect of the refrigerant is obtained, so that the liquid film can be more reliably prevented from growing in a thick layer.
• the first lead angle (H) and the second lead angle (?) are each set with a screw opposite to the pipe axis direction.
• the flow direction is set within the range of 5 ° to 30 °, especially at 18 ° as in the eighth solution, the refrigerant flows in the spiral direction by the main groove (12) and efficiently forms a uniform thin liquid film.
• the scattering action is surely performed by the deformed portion (13).
• each of the first to fourth solving means when the secondary groove (16) is provided in the ridge (15) constituting the main groove (12) as in the ninth solving means, (15) multiple intermittent As a result, a heat transfer area increases. Also, when the secondary groove (16) is provided, a part of the coolant flows to the adjacent main groove (12) by the secondary groove (16) while the spiral flow is generated by the main groove (12). Thus, pressure loss is reduced.
• the secondary groove (16) is arranged at the center of the ridge (15) of the main groove (12) so as to be separated from the irregularly shaped portion (13) by a predetermined distance. Then, the action of the spiral flow by the main groove (12) can be surely performed. In other words, if the secondary groove (16) is arranged close to the irregularly shaped portion (13), the refrigerant will escape from the secondary groove, making it difficult for a spiral flow to occur. Such a fear does not occur.
• the heat transfer area does not increase so much. It is easy to pull out from the groove (16) and hinders the spiral flow. However, if it is within the range of 0.25 to 0.75 as in the first solution, the heat transfer area will be increased. Spiral flow occurs.
• the secondary groove (16) is formed substantially along the pipe axis line as in the first and second solutions, the flow of the refrigerant in the main groove (12) can be compared while enlarging the heat transfer area. Pressure loss can be suppressed because the target is less turbulent.
• the secondary groove (16) is provided in the ridge (15) constituting the main groove (12). Therefore, similarly to the ninth solution, the heat transfer area is increased and the pressure loss is reduced. Then, in the thirteenth solution, a spiral flow is reliably generated by the same operation as in the tenth solution, and in the fourteenth solution, the heat transfer is performed by the same operation as the first solution. A spiral flow is generated while securing the area. In the fifteenth solution, the disturbance of the flow of the refrigerant is suppressed and the pressure loss is reduced by the same operation as the first solution.
• the ratio of the length of the deformed portion (13) is set so as to be in the range of 10% to 35% with respect to the length of one cycle of the groove (11).
• the length of one deformed portion (13) is set within a range of 5 to 15 times the pitch of the groove (11), whereby the groove is formed. Since the liquid refrigerant flowing in the main groove of (11) is made to advance over the plurality of deformed portions (13), the liquid refrigerant is sufficiently scattered at that time. In addition, since the length of the deformed portion (13) and the pitch of the groove (11) are set to the above relationship and are not made longer than necessary, the pressure loss is suppressed while a sufficient scattering action of the liquid refrigerant is obtained. Can be
• the second groove is arranged. Similarly to the means, the liquid refrigerant flowing through the main groove (12) is sufficiently scattered when passing over the plurality of deformed portions (13), and the pressure loss when used in the evaporator can be suppressed.
• the liquid refrigerant is scattered evenly at the joint (14) and the plurality of deformed parts (13) of the electric resistance welded pipe.
• a sufficient scattering effect of the refrigerant in the condenser can be obtained, and the pressure loss in the evaporator can be suppressed by dispersing the deformed portion (13) and the joint (14).
• the liquid refrigerant and the gas refrigerant are evenly dispersed, it is particularly effective for the drift of the refrigerant.
• the heat transfer efficiency can be improved by sufficiently scattering the liquid refrigerant when used as a condenser, and when used as an evaporator, An increase in pressure loss can be suppressed. That is, by using the heat transfer tube with the inner surface groove of each of the above solutions, the performance as a heat exchanger can be improved.
• the first lead angle (h) and the second lead angle (?) are each set at an angle of 5 ° to 30 ° in the opposite twist direction with respect to the pipe axis direction. Within range, especially 8th When the angle is set at 18 ° as in the solution to the above, it is possible to balance the heat transfer efficiency and the pressure loss while securing the effect of the spiral flow.
• the first lead angle (h) is set so that the orientation of the main groove (12) and the deformed portion (13) of the groove (11) is symmetric with respect to the tube axis direction.
• the manufacture of the heat transfer tube (10) becomes relatively easy.
• the heat transfer tube (10) is an electric resistance welded tube
• the angle of the groove or crest of the roll for imprinting the groove (11) on the material of the heat transfer tube (10) can be made symmetrical, and the roll itself can be made.
• the manufacturing of the material becomes easy, and the material is hardly twisted at the time of engraving.
• the secondary groove (16) is provided in the ridge (15) constituting the main groove (12) as in the ninth solution, the heat transfer efficiency can be improved by increasing the heat transfer area. In addition, pressure loss can be reduced. In particular, if the position, depth, angle, and the like of the secondary groove are set to the above-mentioned predetermined values as in the tenth to the twelfth solving means, the effect can be further ensured.
• the secondary groove (16) is provided in the ridge (15) of the main groove (12), the heat transfer efficiency is improved by enlarging the heat transfer area. Therefore, pressure loss can be reduced. More specifically, even if the ratio of the deformed portion (13) in the groove (11) is relatively large, the pressure loss when used as an evaporator can be suppressed, and when used as a condenser. Thus, the effect of scattering the liquid refrigerant can be reliably obtained. Therefore, the performance of the heat exchanger can be enhanced as in the first to fourth solutions.
• FIG. 1 is a partially cutaway front view of an inner grooved heat transfer tube according to an embodiment of the present invention.
• Fig. 2 is an exploded view of a part of the heat transfer tube, showing the shape of the groove.
• FIG. 3 is an enlarged schematic cross-sectional view taken along the line III-III in FIG.
• FIG. 4 is an enlarged view showing the cross-sectional shape of the groove.
• FIG. 5 is a partially enlarged view of FIG.
• FIG. 6 is a perspective view showing a schematic shape of the secondary groove.
• Fig. 7 is a graph showing the condensing capacity as the performance of the heat exchanger alone.
• FIG. 8 is a graph showing the evaporating capacity as the performance of the heat exchanger alone.
• FIG. 9 is a graph showing the evaporation pressure loss with respect to the refrigerant circulation amount.
• FIG. 1 is a partially broken front view of a heat transfer tube (10) having an inner surface groove of the present embodiment.
• the heat transfer tube (10) is formed in a shape bent in a U-shape (a so-called hairpin tube), and on the inner surface, a number of grooves (11) inclined with respect to the tube axial direction are provided. It is formed. Then, by combining the plurality of heat transfer tubes (10) and plate fins (not shown) and appropriately connecting the open ends of the heat transfer tubes (10), a fin coil type heat exchanger is formed. It has become.
• FIG. 2 shows a shape in which a part of the inner grooved heat transfer tube (10) is developed.
• a number of grooves (11) formed on the inner surface of the heat transfer tube (10) have a main groove (12) formed at a first lead angle (h) and a first lead (11).
• a deformed portion (13) formed at a second lead angle (y5) different from the angle (hi) is formed continuously.
• the first lead angle (h) and the second lead angle (?) are set in directions opposite to each other with respect to the pipe axis direction line. Specifically, the first lead angle (h) and the second lead angle ( ⁇ ) are set at 18 ° in opposite directions with respect to the tube axis direction line. For this reason, the main groove (12) of the groove (11) and the deformed portion (13) are formed symmetrically with respect to the pipe axis direction.
• the deformed portion (13) is formed at two places in one cycle of the groove (11).
• two irregularly shaped portions (13) are provided in the groove (11) extending from one circumferential end to the other circumferential end.
• the ratio of the total length of the two deformed portions (13) to the length of one cycle of the groove (11) is set at 28%.
• the deformed portion (13) is set so that each length is approximately 8.5 times the pitch (P) of the groove (11).
• the heat transfer tube (10) is an electric resistance welded tube, and a joint (14) and each deformed portion (13) of the heat transfer tube (10) are enlarged schematic sectional views taken along line III-III in FIG.
• the heat transfer tubes (10) are arranged at positions that divide the circumferential direction of the heat transfer tubes (10) substantially equally, that is, at intervals of approximately 120 °.
• FIG. 4 is an enlarged view showing the cross-sectional shape of the groove (11), and the groove (11) is formed between adjacent ridges (15). In both the main groove (12) and the deformed portion (13), the ridges (15) have the same cross-sectional shape.
• FIG. 5 which is a partially enlarged view of FIG. 2 and FIG. 6 which is a schematic perspective view of the ridge (15)
• the ridge (15) constituting the main groove (12) has a plurality of intermittents.
• a concave portion is formed, and the concave portion forms a secondary groove (16).
• the secondary groove (16) is formed almost only at the center of the ridge (15) of each main groove (12), and a predetermined distance from both ends of each deformed portion (13). Are located at a distance from each other.
• FIG. 2 only the region where the secondary groove (16) is formed is shown in a simplified manner.
• the secondary groove (16) is formed at a depth of about 0.5 times the groove depth of the groove (11). Further, the secondary groove (16) is formed substantially along the pipe axis direction line. Next, the flow of the refrigerant in the heat transfer tube (10) will be described.
• the refrigerant liquefies from the gas phase as it progresses in the condenser, and flows along the main groove (12) of the groove (11). And, since the first lead angle (h) formed by the main groove (12) with respect to the pipe axis direction is set to 18 °, the refrigerant flows helically without fail to form a thin liquid film. Also, in this angle setting, the angle of the helix does not become too large and the pressure loss does not become excessive.
• the first lead angle (H) of the main groove (12) and the second lead angle (; 5) of the deformed portion (13) ) Is different from the variant It collides with the side wall of the ridge (15) of the part (13) and scatters from the inner peripheral surface of the heat transfer tube (10) toward the center.
• the deformed portion (13) is formed with a lead angle of 18 ° in the direction opposite to the main groove (12), and has two deformed portions (1) for one cycle length of the groove (11).
• the ratio of the total length of 13) is 28%, and the length of each deformed portion (13) is set to be about 8.5 times the pitch (P) of the groove (11).
• the refrigerant that has been thinned into a liquid film along the main groove (12) is sure to get over the ridge (15) of the deformed portion (13) many times (in this embodiment, once or twice). As a result, it is difficult to form a thick liquid layer on the inner surface of the heat transfer tube (10), thereby suppressing the generation of an annular flow.
• the ratio of the length of the deformed part to the length of one cycle of the groove (11) (28%) is not too small, and the ratio of the length of the deformed part to the pitch of the groove (8.5 times) Is not too small, and the number of peaks (12) in the deformed area over which the refrigerant can pass is not too small, so that sufficient scattering action can be obtained.
• the joint (14) of the heat transfer tube (10) and the plurality of deformed portions (13) are arranged so as to substantially equally divide the circumferential direction of the heat transfer tube (10), the groove (11)
• the liquid refrigerant flowing through the main groove (12) of the heat transfer tube (10) is evenly scattered in the heat transfer tube (10) at the joint (14) and the deformed portion (13) of the heat transfer tube (10).
• a uniform scattering action of the liquid refrigerant can be obtained over the entire inner surface.
• the ratio (28%) of the length of the irregularly shaped portion (13) to the length of one cycle of the groove (11) is not too large, and the irregularly shaped portion (13) with respect to the pitch of the groove (11) is not too large. Since the ratio of the length (8.5 times) is not too large and the number of protrusions (12) of the deformed portion (13) over which the refrigerant passes is not too large, the pressure loss when used as an evaporator is reduced. Can be suppressed.
• the secondary groove (16) is provided in the ridge (15) constituting the main groove (11), the heat transfer area is increased, and the secondary groove is formed while the spiral flow is generated by the main groove (11).
• the pressure loss is reduced by flowing a part of the refrigerant into the adjacent main groove (11) by the groove (16).
• the pressure loss can be suppressed more reliably while ensuring the action of the spiral flow.
• the heat transfer tube (10) when used as a condenser, the liquid refrigerant can be sufficiently scattered, so that the heat transfer efficiency can be increased.
• an increase in pressure loss can be suppressed.
• the inner surface of the heat transfer tube (10) may be formed into an irregular uneven shape or the like.
• this configuration has an effect of uniformly dispersing the liquid refrigerant and the gas refrigerant, and is particularly effective in preventing the refrigerant from drifting.
• first lead angle (h) and the second lead angle (.?) are set at 18 ° in the opposite torsion direction to the pipe axis direction, the effect of the spiral flow is secured. By scattering the refrigerant, heat transfer efficiency and pressure loss can be balanced at a high level.
• the first lead angle (H) and the second lead angle (5) should be such that the orientation of the main groove (12) and the deformed portion (13) of the groove (11) is symmetrical with respect to the pipe axis direction. Therefore, the manufacture of the heat transfer tube (10) is relatively easy. That is, when the heat transfer tube (10) is an electric resistance welded tube, the angle of the groove or crest of the roll for imprinting the groove (11) on the material of the heat transfer tube (10) can be made symmetric. It is easy to manufacture itself and the material is twisted when engraving. It will be difficult.
• the secondary groove (16) is provided in the ridge (15) constituting the main groove (11), the heat transfer efficiency can be improved by enlarging the heat transfer area, and the pressure loss can be reduced. It can be done. In particular, by setting the position, depth, angle, and the like of the secondary groove to the above-mentioned predetermined values, the effect can be further ensured.
• the provision of the secondary groove (16) is particularly effective in suppressing the pressure loss even when the deformed portion (13) is relatively large.
• the outer diameter (D) is 9.52 mm
• the wall thickness (t) is 0.30 turn
• the groove (11) is 60
• depth of groove (11) (height of ridge (15)) is 0.24mm
• pitch (P) is about 6 °
• angle of peak of ridge (15) is 25 ° Is set to.
• the heat transfer tube (Comparative Example) in which the groove (11) is only the spiral main groove (12) of 18 °, and the groove (11) has the irregular shape with the main groove (12)
• a heat transfer tube (first embodiment) composed of (13) and a heat transfer tube (second embodiment) in which a secondary groove (16) is further formed on the heat transfer tube of the first embodiment are manufactured.
• the results of comparison using the heat exchanger are shown in the graphs of Figs.
• a dashed line indicates a heat transfer tube of a comparative example in which a groove (11) consisting of only a spiral main groove (12) is formed, and a broken line indicates a groove (11) in the main groove (12).
• FIG. 6 shows a heat transfer tube of the first embodiment formed from the heat transfer tube according to the first embodiment formed of the heat transfer tube of the second embodiment in which the deformed portion (13) and the secondary groove (16) are formed in the groove (11). Is shown.
• the condensing capacity of both the heat transfer tube of the first embodiment and the heat transfer tube of the second embodiment is improved with respect to the heat transfer tube of the comparative example.
• the heat transfer tube of the second embodiment has a slightly higher condensation capacity than the heat transfer tube of the first embodiment, and the wind speed at the front of the heat exchanger is low.
• the heat transfer tube of the first embodiment has a slightly higher condensing capacity than the heat transfer tube of the second embodiment.
• the numerical value is almost within the error, Regardless of the presence or absence of the groove (16), it is considered that simply providing the deformed portion (13) is sufficiently effective for the condensation capacity.
• the performance of the heat transfer tube of the first embodiment was improved over the heat transfer tube of the comparative example in all measured wind speed regions, Is even more capable.
• the provision of the secondary groove (16) has a great effect of reducing the pressure loss, and as a result, the evaporation capacity is improved.
• the length of the deformed portion (13) of the groove (11) is set to 28% with respect to the length of one cycle of the groove (11). It should be within the range of 10% to 35%. If this ratio is less than 10%, even if the deformed portion (13) is provided, the liquid refrigerant is hardly scattered in the condenser but sufficient scattering action is obtained. The pressure loss can be suppressed while the pressure loss increases when used in
• the length of the deformed portion (13) is not limited to 8.5 times the pitch of the groove (11), but may be set within a range of 5 times to 15 times. Then, if this value is smaller than 5 times, even if the deformed portion (13) is provided, the liquid refrigerant hardly scatters in the condenser but sufficient scattering action can be obtained, and the value is larger than 15 times When used in an evaporator, the pressure loss increases, but the pressure loss can be suppressed.
• a ridge of a deformed portion (13) intersecting with an extension of one main groove (12) of the groove (11) is not limited to Article 12, and if it is set to Article 5 to Article 15, the pressure when using for the evaporator is ensured while ensuring the refrigerant scattering action when using for the condenser. Losses can be effectively reduced.
• the present invention does not require that all of the above conditions be satisfied, but may include, for example, the ratio of the length of the deformed portion (13) to the length of one cycle of the groove (11). However, if at least one condition is satisfied, it is possible to enhance the heat exchange performance as compared with conventional heat transfer tubes.
• the groove (11) since the provision of the secondary groove (16) has a high effect in preventing the pressure loss from increasing, when the secondary groove (16) is provided, the groove (11) ), The ratio of the deformed portion (13) to one cycle, the relationship between the length of the deformed portion (13) and the pitch of the groove (11), and the deformed portion crossing one main groove (12). The number of (13) may be out of the above range.
• the deformed portion (13) is provided at two places during one cycle of the groove (11), but may be provided at one place or at three or more places. Even in such a case, it is preferable that the joint portion (14) and the deformed portion (13) of the heat transfer tube (10) formed by the electric resistance welded pipe are evenly arranged in the circumferential direction. Even if (13) is provided in two places, it is not always necessary to arrange them evenly.
• first lead angle (h) and the second lead angle (?) are set at 18 ° in the opposite twist direction to the pipe axis direction, but in both cases, the angle is 5 ° to 30 °. Any value within the range is acceptable.
• the two lead angles (h,?) Need not be angles at which the main groove (12) and the deformed portion (13) are symmetrical with respect to the pipe axis direction line.
• the two lead angles (hi,?) Are not the opposite, but can be the same and different angles.
• the secondary groove (16) does not have to be 0.5 times the depth of the groove (11), and if it is formed at a depth of 0.25 times to 0.75 times, heat transfer Spiral flow effect can be obtained while increasing the area. Furthermore, the secondary groove (16) does not necessarily need to be formed along the pipe axis direction, and if the secondary groove (16) is at about 5 ° on both sides with respect to the pipe axis direction, the pressure loss can be maintained even if it is inclined. It is effective in reducing the amount

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• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

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• 2000
  • 2000-04-07 JP JP2000105836A patent/JP2001289586A/ja active Pending
• 2001
  • 2001-04-06 WO PCT/JP2001/003019 patent/WO2001077601A1/ja active IP Right Grant
  • 2001-04-06 CN CN 01810932 patent/CN1253686C/zh not_active Expired - Fee Related
  • 2001-04-06 EP EP01917860A patent/EP1271087A4/en not_active Withdrawn
  • 2001-04-06 AU AU4474001A patent/AU4474001A/xx active Pending
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