JP2007326141A - Method of manufacturing spiral multistage type heat exchanger and spiral multistage type heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a spiral multistage type heat exchanger by which the entire length is continuously wound without relaying connection and productivity is improved. <P>SOLUTION: In the method of manufacturing the spiral multistage type heat exchanger which has a first heat transfer tube in which a first fluid flows and a second heat transfer tube in which a second fluid flows and by which a combined tube in which the second heat transfer tube is wound around the outer periphery of the first heat transfer tube is formed into a planar spiral shape and it is piled up in the multistage, the combined tube is bent from the outer peripheral side of the spiral shape toward the inner peripheral side and, after the bending reaches the approximately center part, the first stage in which the spiral shape is completed is dropped downward by the gravity. Furthermore, the combined tube is wound from the inner peripheral side of the next stage toward the outer peripheral side and, after the bending reaches the outer peripheral side, the second stage is also dropped downward by the gravity. Again, the combined tube is similarly wound from the outer peripheral side of the next stage toward the inner peripheral side. By continuously repeating this work, the continuous spiral multistage type heat exchanger is manufactured. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a spiral multi-stage heat exchanger and a spiral multi-stage heat exchanger in which a spiral shape is formed into a planar shape and is continuously formed in multiple stages without relay connection.

  In the conventional spiral multistage heat exchanger, in order to increase the length of the pipe in a limited space, it is common to perform the relay connection of the pipe at the center or the outer periphery of the spiral end.

In order to improve the shape of the refrigerant-to-water heat exchanger and reduce the size of the heat pump water heater, the first heat transfer tube through which the first fluid flows and the second heat transfer tube through which the second fluid flows are provided. The first heat transfer tube is embedded and integrated with the second heat transfer tube to form a combined tube, the combined tube is formed by bending it into a spiral shape, and the spiral heat exchanger body has a planar shape. A heat exchanger formed so as to be presented has been proposed (see, for example, Patent Document 1).
JP 2004-60906 A

  Conventional swirl multistage heat exchangers are difficult to wind continuously without relay connection for the entire length.Therefore, if there is a relay connection point, the cost becomes high, which is disadvantageous from the viewpoint of ensuring heat exchange efficiency or reliability. There was a problem. In addition, the relay connection work at the center of the spiral is often difficult, which causes a reduction in work time and reliability. Furthermore, it becomes difficult to save space due to the routing of the relay pipe, and it is not easy to check the quality of the connecting part after assembly and correct the defect. Moreover, the discharge | emission property of the fluid in a heat exchanger was bad and had the subject by a liquid pool. Further, when the bending radius is large, not only the space efficiency is bad, but also the shape variation due to the springback occurs, and further, the heat exchange performance is affected.

  This invention has been made to solve the above-described problems, and accommodates longer pipes as heat exchangers in a high-density state without relay connection, and has good drainage of fluid in the heat exchangers. It is an object of the present invention to provide a reliable and inexpensive high-performance spiral multistage heat exchanger with little quality variation and a method for manufacturing the spiral multistage heat exchanger.

  The manufacturing method of the spiral multistage heat exchanger according to the present invention includes a first heat transfer tube through which a first fluid flows and a second heat transfer tube through which a second fluid flows, and the second heat transfer tube is disposed on the outer periphery of the first heat transfer tube. In a manufacturing method of a spiral multi-stage heat exchanger in which a coupling tube around which a heat tube is wound is formed into a spiral shape and stacked in a multistage manner, the coupling tube is moved from the outer periphery side of the spiral shape toward the inner periphery side. Bending, after reaching the substantially central part, the first stage where the spiral shape is completed is dropped by gravity, further bent from the inner periphery side to the outer periphery side of the next stage, and after reaching the outer periphery side, 2 The stage is also dropped downward by gravity, bent again in the same way from the outer circumference side to the inner circumference side of the next stage, and continuously repeated to form a continuous spiral multi-stage heat exchanger It is characterized by.

  The manufacturing method of the spiral multistage heat exchanger according to the present invention can continuously wind the entire length without relay connection by the above configuration, and the productivity is improved.

Embodiment 1 FIG.
FIG. 1 to FIG. 14 are diagrams showing Embodiment 1, FIG. 1 is a plan view of a spiral multistage heat exchanger 5, FIG. 2 is a side view of the spiral multistage heat exchanger 5, and FIG. FIG. 4 is an enlarged view of a portion B of the coupling pipe 3 in FIG. 1, FIG. 5 is an enlarged view showing another example of the coupling pipe 3A, and FIG. 6 is a spiral multi-stage. FIG. 7 is a diagram showing a spiral forming procedure of the spiral multi-stage heat exchanger 5, FIGS. 8 and 9 are diagrams showing individual steps of FIG. 7, and FIG. FIG. 11 is a partial plan view of the spiral multi-stage heat exchanger 5 when the inner bending radius R of the coupling tube 3 and the heat transfer performance are set to be twice the outer bending radius R2. 12 is a partial plan view of the spiral multistage heat exchanger 5 when the bending inner radius R is set to be one time the outer diameter D, and FIG. FIG. 14 is a partial plan view of the spiral multistage heat exchanger 5 when it is 0.75 times as large as FIG. 14, and FIG. 14 is a spiral multistage heat exchanger when the bending inner radius R is 0.5 times the outer diameter D. 5 is a partial plan view of FIG.

  FIG. 1 is a plan view of a three-stage spiral multistage heat exchanger 5 as viewed from above. The spiral multistage heat exchanger 5 is used, for example, in a refrigerant-to-water heat exchanger of a heat pump water heater, and a second fluid is provided on the outer periphery of a first heat transfer tube through which a first fluid (for example, water) flows. The coupling tube 3 spirally wound so as to swirl the second heat transfer tube (for example, refrigerant) is formed in a spiral shape, and this is continuously formed in multiple stages. This will be described later.

  In FIG. 1, the upper spiral shape of the first stage is visible, but as will be described later, the inlet pipe portion 3 a at the beginning of bending is in the lowermost third stage. The position of the inlet pipe portion 3a is determined based on the pipe connection position with the water circuit of the heat pump water heater.

  It is preferable that the position of the outlet pipe portion 3b at the end of bending also coincides with the pipe connection position with the water circuit of the heat pump water heater. However, even if the total length of the coupling pipe 3 is determined due to variation in bending, The position of the part 3b changes each time. In the bending position adjusting portion of FIG. 1, the position of the outlet pipe portion 3b due to bending is adjusted by changing the position of the last bending. The design value is aimed so that the outlet pipe portion 3b comes in the middle of the bending position adjusting portion. When the position of the outlet pipe portion 3b does not reach the reference position, the last bending is performed early. On the other hand, when the position of the outlet pipe portion 3b exceeds the reference position, bending close to the position indicated by the two-dot chain line in FIG. 1 is performed to adjust the position of the outlet pipe portion 3b to the reference position.

  The coupling pipe 3 is bent from the first stage shown in FIG. The first stage bending is performed from the outside to the inside. Each bend is bent at a substantially right angle. In this case, the inner bend R needs to be performed by the inner bend R so that space efficiency and heat transfer performance as a heat exchanger become appropriate values, as will be described later.

  When the first stage bending is completed, the process proceeds to the second stage shown in FIG. In the second stage, the coupling pipe 3 is bent from the inside to the outside.

  When the second stage bending is completed, the process proceeds to the third stage shown in FIG. In the third stage, the coupling pipe 3 is bent from the outside to the inside.

  In the example of FIGS. 1 to 3, the number of stages is three, but it is of course not limited to three.

  Here, the coupling tube 3 will be described. In the example of FIG. 4, the first heat transfer tube 1 through which the first fluid (for example, water) flows is a smooth tube, and the second heat transfer tube 2 through which the second fluid (for example, refrigerant) flows around the outer periphery thereof is spirally wound. Turned. In addition, the outer diameter of the second heat transfer tube 2 wound spirally is defined as the outer diameter D of the coupling tube 3. The outer diameter D of the coupling pipe 3 will be used in later explanation.

  The example of FIG. 5 differs from FIG. 4 in that the first heat transfer tube 1A through which the first fluid flows is a torsion tube. The first heat transfer tube 1A, which is a torsion tube, includes a spiral groove having at least one peak portion 1a and a valley bottom portion 1b on the outer periphery. The inner wall portion 1c of the first heat transfer tube 1A is also shaped along the outer circumferential spiral groove. Also in this case, the outer diameter of the second heat transfer tube 2 wound spirally around the spiral groove is defined as the outer diameter D of the coupling tube 3.

  FIG. 6 shows a continuous right angle bending spiral multistage image of the spiral multistage heat exchanger 5. FIG. 6 shows a case where the number of steps is four, and the first step at the beginning of bending forms a spiral by continuous right-angle bending from the outside to the inside. In the second stage, a spiral is formed by continuous right-angle bending from the inside to the outside. At this time, the first stage falls below the second stage due to gravity and hangs down. The third stage forms a spiral by continuous right-angle bending from the outside to the inside. At this time, the first stage and the second stage fall below the third stage due to gravity and hang down. In the fourth stage, a spiral is formed by continuous right-angle bending from the inside to the outside. At this time, the first to third stages fall below the fourth stage due to gravity and hang down.

  The forming procedure of the spiral multistage heat exchanger 5 will be described with reference to FIG. 9 and 10 show the steps separately.

  In step 1, the coupling tube 3 (or the coupling tube 3 </ b> A) is fed by a predetermined distance and adjusted to the initial bending position.

  In step 2, the coupling tube 3 is bent at a substantially right angle (bending 1).

  In step 3, it is adjusted again to the next bending position by a predetermined distance (the length in the short direction).

  In step 4, the coupling tube 3 is bent at a substantially right angle (bending 2).

  In step 5, the predetermined distance (the length in the longitudinal direction) is again fed and adjusted to the next bending position.

  In step 6, the coupling tube 3 is bent at a substantially right angle (bending 3).

  In step 7, it is adjusted again to the next bending position by a predetermined distance (the length in the short direction).

  In step 8, the coupling tube 3 is bent at a substantially right angle (bending 4). At this time, since the inlet pipe portion 3a which is the tip of the coupling pipe 3 interferes with the supply material, the inlet pipe portion 3a is discharged downward so as not to interfere with the supply material.

  In step 9, it again feeds a predetermined distance (the length in the longitudinal direction) to match the next bending position.

  By repeating the above procedure, the spiral multi-stage heat exchanger 5 is formed with the image of FIG. It is an image in which the bent part is discharged downward and hangs down.

  Next, the inner bending radius R when the coupling tube 3 is bent at a right angle will be described. FIG. 10 is a result of experimentally determining the relationship between the inner bending radius R and the heat transfer performance of the spiral multistage heat exchanger 5 for the coupling tube 3 having the outer diameter D = 20 mm defined above. In FIG. 10, the horizontal axis is the inner bending radius R, the vertical axis is the relative value of the heat transfer performance, and the heat transfer performance when the inner bending radius R = 0.5D is 100%.

  As shown in FIG. 10, when the inner bending radius R is smaller than 0.5D, the coupling tube 3 is bent, so this region is out of range.

  When the inner bending radius R becomes larger than 0.5D, the heat transfer performance gradually decreases, and there is a bending point at a point where the inner bending radius R is about 1.5D. Therefore, it can be said that 0.5D ≦ R <1.5D is a preferable range for the heat transfer performance. The smaller the inner bending radius R, the better the heat transfer performance is that the second heat transfer tube 2 wound around the outer peripheral surface of the coupling tube 3 is kept in a dense state and the flow velocity at the bent portion of the coupling tube 3 However, it is considered that the smaller the inner bending radius R is, the faster the turbulent effect is.

  Next, the relationship between the inner bending radius R and the space efficiency of the spiral multistage heat exchanger 5 will be described with reference to FIGS. 11 to 14. In the case of the inner bending radius R = 2D in FIG. 11 and the inner bending radius R = 2D in FIG. 12, there is no space for bending the coupling tube 3 in the vicinity of the center as shown in each figure, and the space efficiency is poor. In the case of the inner bending radius R = 0.75D in FIG. 13 and the inner bending radius R = 0.5D in FIG. 14, there is a space for bending the coupling tube 3 near the center, and the space efficiency is good. Therefore, it can be said that the inner bending radius R ≦ 5 / 6D is preferable for the space efficiency.

  In consideration of both heat transfer performance and space efficiency, the inner bending radius R is 0.5D ≦ R ≦ 5 / 6D.

  In the above description, the coupling pipe 3 is bent at a right angle, but it may be curved.

  As described above, according to the present embodiment, it is possible to wind in a spiral shape without considering the space for relay connection of the pipe at the center of the spiral, which enables high-density storage of the pipe. Become. In addition, since it is bent at a right angle, high-speed automation is possible with little variation in the bending shape. Further, as shown in FIG. 1, the pipe outlet position is fixed by arbitrarily adjusting the bending position of the outlet pipe portion 3b (bending end side) in the longitudinal direction. In other words, since the ends of the inlet pipe portion 3a and the outlet pipe portion 3b of the pipe are accurately arranged at arbitrary positions on the outer periphery or the center of the spiral, the pipe connection at the time of forming the unit (water circuit) in the subsequent process It becomes easy.

FIG. 5 is a diagram showing the first embodiment, and is a plan view of a spiral multistage heat exchanger 5. FIG. FIG. 2 is a diagram showing the first embodiment, and is a side view of a spiral multistage heat exchanger 5. FIG. FIG. 3 is a diagram showing the first embodiment, and is a plan view of the first stage from the line AA in FIG. 2. FIG. 2 is a diagram showing the first embodiment, and is an enlarged view of part B of the coupling pipe 3 in FIG. 1. It is a figure which shows Embodiment 1, and is an enlarged view which shows 3 A of coupling pipes of another example. FIG. 5 is a diagram illustrating the first embodiment and is an image diagram illustrating multi-stages of the spiral multi-stage heat exchanger 5. FIG. 5 is a diagram illustrating the first embodiment and is a diagram illustrating a spiral forming procedure of the spiral multistage heat exchanger 5. It is a figure which shows Embodiment 1, and is a figure which shows each step of FIG. 7 separately. It is a figure which shows Embodiment 1, and is a figure which shows each step of FIG. 7 separately. FIG. 5 is a diagram illustrating the first embodiment and is a diagram illustrating a relationship between an inner bending radius R of a coupling pipe 3 and heat transfer performance. FIG. 5 shows the first embodiment, and is a partial plan view of the spiral multistage heat exchanger 5 when the bending inner radius R is twice the outer diameter d2. FIG. 5 shows the first embodiment, and is a partial plan view of the spiral multistage heat exchanger 5 when the bending inner radius R is set to be one time the outer diameter D. FIG. FIG. 5 shows the first embodiment, and is a partial plan view of the spiral multistage heat exchanger 5 when the bending inner radius R is 0.75 times the outer diameter D. FIG. FIG. 5 shows the first embodiment, and is a partial plan view of the spiral multistage heat exchanger 5 when the bending inner radius R is 0.5 times the outer diameter D. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 1st heat exchanger tube, 1a peak part, 1b valley bottom part, 1c pipe inner wall part, 2nd heat transfer pipe, 3 coupling pipe, 3A coupling pipe, 3a inlet pipe part, 3b outlet pipe part, 5 spiral multistage heat exchanger .

Claims (9)

A first heat transfer tube through which the first fluid flows and a second heat transfer tube through which the second fluid flows, and a joint tube in which the second heat transfer tube is wound around the outer periphery of the first heat transfer tube is swirled in a plane. In the manufacturing method of the spiral multistage heat exchanger formed in a shape and stacked in multiple stages,
The coupling tube is bent from the outer periphery side of the spiral shape toward the inner periphery side, and after reaching the substantially central portion, the first stage where the spiral shape is completed is dropped downward by gravity, and further from the inner periphery side of the next stage. Bend toward the outer periphery, and after reaching the outer periphery, the second step is also dropped downward due to gravity, and again bent in the same way from the outer periphery to the inner periphery of the next step. A process for producing a spiral multi-stage heat exchanger, characterized by being repeated to form a continuous spiral multi-stage heat exchanger.   2. The method of manufacturing a spiral multistage heat exchanger according to claim 1, wherein the coupling pipe is bent at a substantially right angle.   The inner bending radius R of the coupling tube when the coupling tube is bent at a substantially right angle is 0.5D ≦ R <1.5D, where D is the outer diameter of the coupling tube. Item 3. A method for producing a spiral multistage heat exchanger according to Item 2.   The inner bending radius R of the coupling pipe when the coupling pipe is bent at a substantially right angle is 0.5D ≦ R ≦ 5 / 6D, where D is the outer diameter of the coupling pipe. Item 4. A method for producing a spiral multistage heat exchanger according to Item 3.   The spiral shape of the final stage of the coupling pipe is bent from the outer peripheral side toward the inner peripheral side, and the outlet pipe by bending is changed by changing the position of the last approximately 180 degrees bending on the inner peripheral side. The manufacturing method of the spiral multistage heat exchanger according to any one of claims 1 to 4, wherein the variation of the position of the portion is adjusted. A first heat transfer tube through which the first fluid flows and a second heat transfer tube through which the second fluid flows, and a joint tube in which the second heat transfer tube is wound around the outer periphery of the first heat transfer tube is swirled in a plane. In a spiral multistage heat exchanger formed into a shape and stacked in multiple stages,
At least one of the spiral shapes located at the end portion is such that one end portion of the coupling tube is located on the outer peripheral side, and is continuously shifted from the substantially central portion on the inner peripheral side to the next spiral shape. In the spiral shape, a spiral is formed from the inner peripheral side to the outer peripheral side, and continuously moves from the outer peripheral side to the outer peripheral side of the next spiral shape, and the further next spiral shape is directed from the outer peripheral side to the inner peripheral side. The spiral multistage heat exchanger is characterized in that spirals are formed and the planar spiral shape is stacked in multiple stages by repeating this process.   The spiral multistage heat exchanger according to claim 6, wherein the spiral-shaped coupling pipe is bent at a substantially right angle.   The inner bending radius R of the coupling tube when the coupling tube is bent at a substantially right angle is 0.5D ≦ R <1.5D, where D is the outer diameter of the coupling tube. Item 8. The spiral multistage heat exchanger according to Item 7.   The inner bending radius R of the coupling pipe when the coupling pipe is bent at a substantially right angle is 0.5D ≦ R ≦ 5 / 6D, where D is the outer diameter of the coupling pipe. Item 9. The spiral multistage heat exchanger according to Item 8.