JP2008249163A - Heat exchanger for supplying hot water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve heating performance especially at an outlet high-temperature area of a heat exchanger for supplying hot water including a core pipe and an outer pipe. <P>SOLUTION: This heat exchanger for supplying hot water includes the core pipe 1 forming a water passage 2 and outer pipes 3A, 3B forming refrigerant passages 3a, 3b joined to the outer periphery of the core pipe 1, and the heat exchanger is configured to perform heat exchange between water and a refrigerant. An outlet side part with a predetermined length in the core pipe 1 where high-temperature water flows is formed of a corrugated pipe, the inner surface of which is provided with circumferential projection projected toward the central axis of the pipe. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat exchanger for hot water supply, and more specifically, a hot water supply comprising a core tube that forms a water passage and an outer tube that is joined to the outer periphery of the core tube to form a refrigerant passage, and performs heat exchange between water and the refrigerant The present invention relates to a heat exchanger for use.

  A hot water supply heat exchanger composed of a core tube that forms a water passage and an outer tube that is joined to the outer periphery of the core tube to form a refrigerant passage has been well known, for example, as a heat pump water heater (for example, (Refer FIGS. 1-5 of patent document 1). In the case of this conventional heat exchanger for hot water supply, an inner smooth tube having a smooth inner wall surface is used for both the water-side core tube and the refrigerant-side outer tube.

  However, recently, with the demand for higher performance and more compact hot water supply devices, higher performance of the heat exchanger itself is required. Therefore, a high-performance pipe having a high heat transmissivity compared to an inner smooth pipe such as an inner grooved pipe having a spiral or V-shaped concave groove on the inner wall surface is used as the water-side core pipe. It has been proposed (see, for example, FIGS. 3 and 4 of Patent Document 2).

JP 2003-97889 A JP 2005-221172 A

  As described above, when a high-performance pipe such as an internally processed pipe having a spiral or V-shaped concave groove formed on the inner wall surface is used as the core pipe forming the water passage, the boiling temperature (for example, 90 ° C.) It is effective for the rise. However, in the heat exchanger for hot water supply as described above, there is a problem that a scale component (for example, calcium carbonate) dissolved in water precipitates and adheres to the inner wall of the water passage as the temperature of water increases.

  That is, although calcium carbonate is dissolved in tap water, the solubility of the calcium carbonate decreases as the water temperature rises and precipitates as a scale component. Then, the deposited scale component accumulates in the concave groove portion of the inner wall of the water passage, resulting in clogging, the heat transfer performance is reduced, and the inner diameter of the pipe is reduced to increase the pressure loss. Therefore, in the above-described conventional example, the high-performance pipe having the recessed groove portion on the inner wall surface is adopted only for the inlet side portion where the water temperature is equal to or lower than the predetermined temperature. For this reason, there has been a limit in improving the water heating performance of the heat exchanger for hot water supply.

  Therefore, in order to solve such a problem, for example, it is possible to enlarge the diameter of the outlet side portion of the core tube and use an internally grooved tube on the tube diameter. The boundary layer agitation action of the concave groove portion does not function and the use of the high performance tube is substantially lost.

  The present invention was made based on such circumstances, and in particular, the corrugated corrugate has a circumferential ridge that protrudes toward the central axis of the tube at the outlet side portion of the core tube through which high-temperature water flows. It is an object of the present invention to provide a high-performance hot water supply heat exchanger that does not cause clogging due to the scale as described above even when the water temperature is high, and does not deteriorate the heat transfer performance.

  In order to achieve the above object, the present invention is configured with the following problem solving means.

(1) Invention of Claim 1 A heat exchanger for hot water supply of the present invention includes a core tube 1 that forms a water passage 2 and an outer tube 3A that forms refrigerant passages 3a and 3b joined to the outer periphery of the core tube 1. consists of a 3B, water and a hot water heat exchanger for heat exchange of the refrigerant, the outlet side by a predetermined length L ₁ portion of the core tube 1 through which water temperatures above the predetermined temperature, the tube to the inner surface center It is characterized in that it is formed by a corrugated pipe having circumferential ridges 11, 11... That are convex in the axial direction.

Thus, the predetermined length L ₁ portion of the core tube outlet water temperature is higher than a predetermined temperature, there is a circumferential direction of the ridges 11, 11 ... that is convex toward the tube central axis to the inner surface When a corrugated tube is used, the circumferential ridges 11, 11... Expand the heat transfer area of the tube inner wall, effectively destroy the boundary layer, and are difficult to adhere to scale due to calcium carbonate as described above. There is no clogging.

  Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

(2) Invention of Claim 2 The heat exchanger for hot water supply of this invention is a structure of invention of the said Claim 1, WHEREIN: The circumferential protruding item | line 11,11 ... is what continues spirally. It is characterized by.

  According to such a spiral ridge configuration, the spiral ridges 11, 11,... In the circumferential direction expand the heat transfer area of the inner wall of the tube, and effectively destroy the boundary layer, and Such scales due to calcium carbonate are difficult to adhere and clogging does not occur.

  Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

(3) Invention of Claim 3 The heat exchanger for hot water supply of this invention is the structure of the invention of the said Claim 1, and the protruding item | line of the circumferential direction is divided | segmented into the ring shape, It is characterized by the above-mentioned.

  According to the convex strip configuration divided in such a ring shape, the ring-shaped convex strips 11, 11, ... in the circumferential direction expand the heat transfer area of the inner wall of the pipe, and effectively destroy the boundary layer, Moreover, the scale due to calcium carbonate as described above becomes difficult to adhere, and clogging due to the occurrence of clogging does not occur.

  Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

(4) Invention of Claim 4 The heat exchanger for hot water supply of this invention is the structure of the invention of said Claim 2, WHEREIN: The convex line | wire of the circumferential direction is formed with a twist angle of less than 45 degrees. It is characterized by.

  According to the spiral ridge configuration in such a twist angle range, the spiral ridges 11, 11... Extending in the circumferential direction at the same twist angle expand the heat transfer area of the inner wall of the pipe and the boundary layer. It breaks down effectively, and the scale due to calcium carbonate as described above becomes difficult to adhere, and clogging due to clogging does not occur.

  Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

(5) Invention of Claim 5 The heat exchanger for hot water supply of this invention is the pitch P between the circumferential ridges 11, 11 ... in the structure of the invention of the said Claim 1, 2, 3 or 4 said. And the inner diameter Di of the core tube 1 is characterized in that P / Di is 1 or less.

  According to the ridge configuration having such a pitch P and an inner diameter Di range, the ridges 11, 11,... In the circumferential direction having the P / Di of 1 or less effectively expand the heat transfer area of the inner wall of the tube. In addition, the boundary layer is effectively destroyed, and the scale due to the calcium carbonate as described above becomes difficult to adhere and clogging does not occur.

  Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

  As a result of the above, according to the hot water supply heat exchanger of the present invention, it is possible to provide a high-performance hot water supply heat exchanger with a small performance deterioration due to scale adhesion and high heating performance at a relatively low cost.

  Hereinafter, the configuration and operation of the present invention will be described in detail by exemplifying several best possible embodiments for carrying out the invention.

<First Embodiment>
First, FIG. 1 shows the configuration of a hot water supply heat exchanger according to the first embodiment of the present invention suitable for use in the hot water supply heat exchanger for the heat pump hot water supply apparatus described above.

(Overall configuration of heat exchanger for hot water supply: FIGS. 1 to 4)
As shown in FIGS. 2 to 4, for example, the heat exchanger for hot water supply is provided on the outer periphery of a core tube 1 having a predetermined length (for example, about 10 m) that forms a water passage 2 therein, and a refrigerant passage 3 a inside. , 3b, the first and second outer tubes 3A, 3B having a smaller diameter (outer diameter and passage diameter) than the core tube 1 are spirally wound at a predetermined pitch (for example, 30 mm), The two contact portions 1c, 1c,... Are brazed or soldered and wound into an oval spiral shape as shown in FIG.

  Then, for example, the heat exchanger unit 10 is overlapped by a plurality of stages, and then the inner ends of the core tube 1 and the outer tubes 3A and 3B are connected in series by a predetermined connecting tube, and brazed. The core tube 1 side is used as a water passage 2, and the first and second outer pipes 3A and 3B are formed as high-temperature refrigerant passages 3a and 3b, respectively. ing.

According to such a configuration of the hot water supply heat exchanger 10, the water W ₁ flowing in the water passage 2 is heated by the high-temperature refrigerant (for example, CO ₂ ) flowing in the first and second refrigerant passages 3a and 3b. Thus, the temperature is raised efficiently, and hot water is supplied to the outside as hot water W ₂ having a desired temperature (for example, about 90 ° C.).

(Specific configuration of core tube portion: FIGS. 3, 4, and 5)
By the way, in the case of such a heat exchanger 10 for hot water supply, an inner surface smooth tube having a smooth inner wall surface is generally used for the water-side core tube 1 and the refrigerant-side thin outer tubes 3A and 3B. It had been.

  However, recently, with the demand for higher performance and more compact heat pump type hot water supply devices, higher performance of the heat exchanger itself is required. Therefore, as already described, the use of a high-performance pipe having a high heat transmissivity compared to a smooth pipe such as an internally grooved pipe has been studied for the water-side core pipe 1.

  When a high performance tube such as an internally processed tube having a spiral or V-shaped groove formed on the inner wall surface is used as the core tube 1, it is effective for raising the boiling temperature (for example, 90 ° C.) When looking at the span of use, the heating performance can be greatly improved. However, in the heat exchanger for hot water supply as described above, there is a problem that a scale component (for example, calcium carbonate) dissolved in water precipitates and adheres to the inner wall of the passage as the temperature of water increases.

  That is, although calcium carbonate is dissolved in tap water, the solubility of this calcium carbonate decreases as the water temperature rises and precipitates as a scale component. As a result, when viewed over a long span of use, the deposited scale component accumulates in the concave groove portion of the inner wall of the water passage in the core tube 1 to cause clogging. This causes a problem that the pressure loss increases due to the reduction.

  Therefore, so far, the high-performance pipe formed with the concave groove portion on the inner wall surface as described above is limited to the inlet side portion of the core pipe 1 whose water temperature is not more than a predetermined temperature. It is a fact. For this reason, there has been a limit in improving the water heating performance of the heat exchanger for hot water supply.

  Further, in order to solve such a problem, for example, an inner diameter processed pipe having a concave groove portion on the outlet diameter side of the core tube 1 where the water temperature becomes higher than a predetermined temperature is enlarged. However, depending on the tube diameter, the original boundary layer breaking action of the groove formed by the narrow groove does not function and the use of the high performance tube is substantially lost.

The present invention has been made based on such circumstances, and is a predetermined length L ₂ position from the water inlet 1 a side to the water outlet 1 b side of the core tube 1 (for example, a position of about 8 m when the total length is 10 m). Up to this point, for example, an inner surface smooth tube as shown in FIG. 3 is used, but the core tube 1 extends in the direction of the water outlet 1b from the same position where high-temperature water of a predetermined temperature (for example, 70 ° C.) or more flows. The predetermined length L ₁ portion (remaining 2 m portion) to the water outlet 1b is, for example, a predetermined pitch (for example, about 8 mm) in the circumferential direction protruding toward the tube central axis direction on the inner wall surface as shown in FIG. Is formed by a corrugated tube in which spiral ridges 11, 11... That are swirled are formed, thereby enlarging the heat transfer area of the inner wall surface of the tube as much as possible and stirring the water flow by the ridges. Destroys the temperature boundary layer efficiently, However, even if the water temperature becomes high (for example, 70 ° C. or higher) and the scale is likely to precipitate, the above-described clogging is unlikely to occur and the heat transfer performance is not easily lowered.

That is, in the case of this configuration, for example, as shown in FIG. 4, when water W ₁ whose scale is deposited and flows on the ridge 11 part flows, the scale component is caused by the locking wall function on the front surface 11 a side. The amount that is locked and deposited and flows over the ridge 11 and flows downstream is reduced.

  As a result, the scale hardly adheres to the inner wall surface of the core tube between the back surface 11b side of the ridge 11 and the vicinity of the front surface of the next ridge 11.

That is, according to the above configuration, a conventional calcium carbonate is provided between the spiral ridges 11, 11... In the water outlet 1b side L ₁ (2 m) region where the water temperature is 70 ° C. or more. This makes it difficult for the scale to adhere to the surface, so that a wide and effective heat transfer area can be secured. Therefore, it is not necessary to deteriorate the temperature boundary layer destruction function and the heat transfer performance of the inner wall surface of the core tube 1.

  As a result, despite the high heat transfer performance and high performance, it is possible to realize a high-performance hot water supply heat exchanger at a low cost that does not significantly degrade the conventional heat transfer performance due to scale adhesion. It becomes.

  Of course, in this case as well, an inner surface groove similar to the conventional one is formed in a predetermined length portion in the direction from the inlet 1a to the outlet 1b of the core tube 1 where the temperature of water is less than a predetermined temperature (70 ° C.) and scale does not easily precipitate. You may make it employ | adopt inner surface processing pipe | tubes, such as an attachment pipe | tube, If it does in that way, heating performance can be improved more effectively.

  In the above configuration, the relationship between the pitch P between the circumferential ridges 11, 11... And the inner diameter Di of the core tube 1 (see FIG. 5B) is P / Di. It is preferably 1 or less, more specifically 0.2 to 1.0.

According to the ridge structure having such a pitch P and an inner diameter Di range, the scale is hardly adhered to the water outlet side region L _{1 of the} core tube 1 having a high water temperature by the calcium carbonate, and the most effective boundary layer destruction and propagation are achieved. The effect of improving thermal performance is realized.

  In this case, if the height of each of the spiral ridges 11, 11,... Is Dh, the height D has a relationship of 0.05 to 0.15 with respect to the inner diameter Di. It is preferable (Dh / Di = 0.05 to 0.15).

  Furthermore, the circumferential spiral ridges 11, 11,... Are preferably formed with a twist angle of less than 45 °.

  According to such a spiral ridge configuration with a twist angle range, the spiral ridges 11, 11... In the circumferential direction effectively expand the heat transfer area of the inner wall of the pipe, and the boundary layer It breaks down effectively, and the scale due to calcium carbonate as described above becomes difficult to adhere and clogging does not occur.

  Therefore, although it has high heat transfer performance and high performance, it is suitable for realizing a high-performance hot water supply heat exchanger in which a decrease in heat transfer performance due to scale adhesion is small.

<Second Embodiment>
Next, FIG. 6 (a), (b) shows the structure of the heat exchanger for hot water supply which concerns on the 2nd Embodiment of this invention suitable for using for the heat exchanger for hot water supply for heat pump type hot water supply apparatuses similarly. ing.

  In the configuration of the first embodiment, when the spiral ridges 11, 11,... Are provided on the inner peripheral surface of the core tube 1, as shown in FIGS. A corrugated tube was formed by cutting (or bonding) the inner peripheral surface of the core tube 1 while keeping the outer peripheral surface smooth.

  However, in this embodiment, for example, as shown in FIG. 6, the first embodiment is applied to the inner wall surface side by rolling from the outer peripheral surface side of the core tube 1 and denting the outer wall surface of the core tube 1. Are formed with spiral ridges 11, 11.

  Even with such a configuration, the same operation as that of the first embodiment can be realized, and since the processing itself is simple, it can be manufactured at a lower cost.

(Modification)
7A and 7B show a modification of the second embodiment.

  In the first and second embodiments described above, the relationship with the number of outer tubes 3 is not a problem in either case.

  However, as a method of winding the outer tube 3, two (or more) as shown in FIGS. 1 to 3 may be wound in parallel, or may be one. Therefore, in such a case, even if the pitch between the outer tubes 3, 3... Is constant, the lead angle of each outer tube 3 increases with the number.

  Therefore, considering the same situation, for example, as shown in FIGS. 7A and 7B, the lead angle of the spiral ridges 11, 11,... To do.

<Third Embodiment>
Next, FIG. 8 shows the configuration of a hot water supply heat exchanger according to the third embodiment of the present invention suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  In this embodiment, the circumferential ridges 11, 11,... Are formed by cutting (or bonding) the inner wall surface of the core tube 1 as in the first embodiment. In this case, the circumferential ridges 11, 11,... Are not continuous in a spiral shape, but are independent in a ring shape.

Also the configuration of each such ring-shape shed circumferential direction of the projections 11, 11 ..., the higher the exit side L ₁ length of the core tube 1 of the water temperature, the scale by calcium carbonate as described above It is possible to realize a high-performance hot water supply heat exchanger that has a small deterioration in heat transfer performance due to scale adhesion, despite its high heat transfer performance and high performance. Become.

<Fourth Embodiment>
Next, FIG. 9 shows the configuration of a hot water supply heat exchanger according to the fourth embodiment of the present invention, which is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  In this embodiment, as in the second embodiment, the circumferential ridges 11, 11,... Are formed by rolling the outer wall surface of the core tube 1, The circumferential ridges 11, 11,... Are not continuous in a spiral shape, but are independent in a ring shape.

Also with the configuration of the ridges 11, 11... Each divided in a ring shape, the above-described scale made of calcium carbonate is made difficult to adhere to the outlet side L ₁ portion of the core tube 1 having a high water temperature. Therefore, it is possible to realize a high-performance hot water supply heat exchanger in which the deterioration in heat transfer performance due to scale adhesion is small despite high heat transfer performance and high performance.

<Fifth Embodiment>
Next, FIG. 10 shows the configuration of a hot water supply heat exchanger according to the fifth embodiment of the present invention that is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  For example, an inner grooved tube with various concave grooves such as spiral grooves, V-shaped grooves, W-shaped grooves, etc., says that scales are easy to deposit, but that is due to the relationship between water temperature and water quality. It is a story in an easy area.

  Therefore, for example, when standard tap water is used as a standard, for example, in the region where the water temperature is less than 70 ° C., there is not so much precipitation of scale, and it is possible to use the inner surface grooved tube. However, the heating performance is also improved.

Therefore, in this embodiment, for example, as shown in FIG. 10, in the region L ₂ portion from the water inlet 1a of the core tube 1 to the water temperature of less than 70 ° C., for example, the spiral groove 12 described above on the inner wall surface. While the heat transfer performance is improved as much as possible by using the inner surface processed tube having the water temperature, the region L ₁ up to the water outlet 1b side where the downstream water temperature becomes higher than 70 ° C. and the scale is likely to precipitate. In the portion, the corrugated pipe of the first embodiment is hardly deposited even if scale is deposited and the heat transfer performance is not easily lowered. I am doing so.

<Sixth Embodiment>
Next, FIG. 11 shows the configuration of a hot water supply heat exchanger according to the sixth embodiment of the present invention, which is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  The configuration of this embodiment is similar to the configuration of the fifth embodiment described above in the configuration of the third embodiment described above, and is combined with an inner surface processed tube having a spiral groove 12 to produce heat. The heating performance of the entire exchanger is improved as effectively as possible.

<Seventh Embodiment>
Next, FIG. 12 shows the configuration of a hot water supply heat exchanger according to the seventh embodiment of the present invention suitable for use in a hot water supply heat exchanger for a heat pump hot water supply device.

  The configuration of this embodiment is the same as that of the above-described fifth embodiment in the configuration of the above-described second embodiment. The heating performance of the entire exchanger is improved as effectively as possible.

<Eighth Embodiment>
Next, FIG. 13 shows the configuration of a hot water supply heat exchanger according to an eighth embodiment of the present invention suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  The configuration of this embodiment is similar to the configuration of the fourth embodiment described above in the case of the fifth embodiment, and is combined with an inner surface processed tube having a spiral groove 12 to exchange heat. The heating performance of the entire vessel has been improved as effectively as possible.

<Ninth Embodiment>
Next, FIG. 14 and FIG. 15 show the configuration of a hot water supply heat exchanger according to the ninth embodiment of the present invention suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  Although the corrugated pipe having the ridges 11, 11,... In the circumferential direction on the inner wall as described above does not necessarily deposit at all, although it is difficult to deposit scales, at least near the front surface of the ridges 11. The deposition of a certain amount of scale is inevitable.

  Therefore, in this embodiment, as shown in FIGS. 14 and 15, the pipe diameter of the corrugated pipe portion on the water outlet 1b side in the fifth embodiment of FIG. It is characterized by doing so.

  In the case of the spiral ridges 11, 11,... In the circumferential direction described above, even if the pipe diameter is enlarged, unlike the case of the concave groove portion that has a predetermined raised height and is a narrow groove, the temperature The boundary layer destruction function is not lost.

  Therefore, the heat transfer performance is sufficiently improved and the scale is less likely to adhere and deposit, which is effective for improving the heating performance in a high temperature range.

<Tenth Embodiment>
Next, FIG. 16 shows the configuration of a hot water supply heat exchanger according to the tenth embodiment of the present invention that is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  As described above, the corrugated pipe having the ridges 11, 11,... In the circumferential direction on the inner wall surface is not deposited at all, although it is difficult to deposit the scale, at least near the front surface of the ridge 11. The deposition of a certain amount of scale is inevitable.

  Therefore, in this embodiment, for example, as shown in FIG. 16, the diameter of the corrugated pipe portion on the water outlet 1b side in the above-described sixth embodiment of FIG. It is characterized by that.

  In the case of the spiral ridges 11, 11,... In the circumferential direction described above, even if the pipe diameter is enlarged, unlike the case of the concave groove portion that has a predetermined raised height and is a narrow groove, the temperature The boundary layer destruction function is not lost.

  Therefore, the heat transfer performance is sufficiently improved and the scale is less likely to adhere and deposit, which is effective for improving the heating performance in a high temperature range.

<Eleventh embodiment>
Next, FIG. 17 shows the configuration of a hot water supply heat exchanger according to an eleventh embodiment of the present invention, which is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  As described above, the corrugated pipe having the convex ridges 11, 11,... In the circumferential direction on the inner peripheral surface does not necessarily deposit at all, although it is difficult to deposit the scale. A certain amount of scale is inevitable.

  Therefore, in this embodiment, for example, as shown in FIG. 17, the diameter of the corrugated pipe portion on the water outlet 1b side in the above-described seventh embodiment of FIG. It is characterized by that.

  In the case of the spiral ridges 11, 11,... In the circumferential direction described above, even if the pipe diameter is enlarged, unlike the case of the concave groove portion that has a predetermined raised height and is a narrow groove, the temperature The boundary layer destruction function is not lost.

  Therefore, the heat transfer performance is sufficiently improved and the scale is less likely to adhere and deposit, which is effective for improving the heating performance in a high temperature range.

<Twelfth Embodiment>
Next, FIG. 18 shows the configuration of a hot water supply heat exchanger according to the twelfth embodiment of the present invention, which is also suitable for use in a hot water supply heat exchanger for a heat pump hot water supply apparatus.

  As described above, the corrugated pipe having the convex ridges 11, 11,... In the circumferential direction on the inner peripheral surface does not necessarily deposit at all, although it is difficult to deposit the scale. A certain amount of scale is inevitable.

  Therefore, in this embodiment, as shown in FIG. 18, for example, the diameter of the corrugated pipe portion on the water outlet 1b side in the above-described eighth embodiment of FIG. It is characterized by that.

  In the case of the spiral ridges 11, 11,... In the circumferential direction described above, even if the pipe diameter is enlarged, unlike the case of the concave groove portion that has a predetermined raised height and is a narrow groove, the temperature The boundary layer destruction function is not lost.

  Therefore, the heat transfer performance is sufficiently improved and the scale is less likely to adhere and deposit, which is effective for improving the heating performance in a high temperature range.

BRIEF DESCRIPTION OF THE DRAWINGS It is a general view which shows the structure of the heat exchanger for hot water supply which concerns on 1st Embodiment of this invention. It is a partially expanded perspective view which shows the structure of the principal part of the same heat exchanger. It is an expanded sectional view of the inner surface smooth tube part of the principal part of the heat exchanger. It is an expanded sectional view of the corrugated pipe part of the heat exchanger principal part. (A) is an external appearance perspective view of the corrugated pipe part of the heat exchanger, and (b) is a partially cutaway perspective view of the corrugated pipe part. (A) is a whole figure which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the 2nd Embodiment of this invention, (b) is one of the corrugated pipe parts. It is a part notch perspective view. (A) is a perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the modification of the 2nd Embodiment of this invention, (b) is the corrugated pipe part FIG. (A) is a perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the 3rd Embodiment of this invention, (b) is one of the corrugated pipe parts. It is a part notch perspective view. (A) is a perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on the modification of the 4th Embodiment of this invention, (b) is the corrugated pipe It is a partially cutaway perspective view of a part. It is a partially notched perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on 5th Embodiment of this invention. It is a partially notched perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the 6th Embodiment of this invention. It is a partially notched perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the 7th Embodiment of this invention. It is a partially notched perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply concerning the 8th Embodiment of this invention. It is a general view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on the modification of the 8th Embodiment of this invention. It is a partially notched perspective view which shows the structure of the principal part of the same heat exchanger. It is a partial notch perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on 9th Embodiment of this invention. It is a partial notch perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on 10th Embodiment of this invention. It is a partial notch perspective view which shows the external structure of the corrugated pipe part which is the principal part of the heat exchanger for hot water supply which concerns on 11th Embodiment of this invention.

Explanation of symbols

  1 is a core tube, 2 is a water passage, 3A and 3B are outer tubes, 3a and 3b are refrigerant passages, and 11 is a circumferential ridge.

Claims (5)

From the core tube (1) forming the water passage (2) and the outer tubes (3A) and (3B) forming the refrigerant passages (3a) and (3b) joined to the outer periphery of the core tube (1) will, be water and the hot water supply heat exchanger for exchanging heat of the coolant, the core pipe through which water temperatures above the predetermined temperature the outlet side by a predetermined length L ₁ part of (1), the tube axial direction on the inner surface A heat exchanger for hot water supply, characterized in that it is formed by a corrugated pipe with circumferential ridges (11), (11).   The heat exchanger for hot water supply according to claim 1, wherein the circumferential ridges (11), (11), ... are continuous in a spiral shape.   2. The hot water supply heat exchanger according to claim 1, wherein the circumferential ridges (11), (11)... Are divided into ring shapes.   The heat exchanger for hot water supply according to claim 2, characterized in that the circumferential ridges (11), (11), ... are formed with a twist angle of less than 45 °.   2. The relationship between the circumferential ridges (11), (11)... And the inner diameter Di of the core tube (1) is such that P / Di is 1 or less. , 2, 3 or 4 hot water supply heat exchanger.

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