Heat exchanger

Abstract

To provide a heat exchanger in which the efficiency of heat exchange is improved by making the fluid turbulent.SOLUTION: A heat exchanger includes: a pipe that conducts heat exchange between a first fluid flowing therein and a second fluid outside the pipe; and a plurality of vanes that are provided at two or more locations in the pipe and that make the first fluid rotate around the axial direction of the pipe, wherein there are a plurality of ribs extending in a direction extending along the pipe on an inner surface of a portion of the pipe that is sandwiched between at least two vanes in a direction extending along the pipe.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat exchanger. [Background technology]

[0002] For example, Patent Document 1 describes a double-pipe heat exchanger that has an inner pipe and an outer pipe outside the inner pipe, and exchanges heat between a fluid flowing in the inner pipe and a fluid flowing between the inner pipe and the outer pipe. In Patent Document 1, the inner pipe is twisted in a spiral shape, and a swirl portion is provided on the outer periphery of a plate-like member provided on the outer surface of the inner pipe, thereby promoting turbulence of the fluid flowing between the inner pipe and the outer pipe and improving heat exchange performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-005990 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, promoting turbulence in the fluid flowing inside the pipes is known as a method for improving the heat exchange efficiency of a heat exchanger.

[0005] An object of the present invention is to provide a heat exchanger in which the heat exchange efficiency is improved by turbulence of a fluid. [Means for solving the problem]

[0006] The heat exchanger of the present invention comprises a pipe that exchanges heat between a first fluid flowing inside and an external second fluid, and a plurality of blade bodies provided at two or more locations within the pipe for swirling the first fluid around the axial direction of the pipe, and a plurality of ribs extending in the extension direction of the pipe are provided on the inner surface of a portion of the pipe that is sandwiched between at least two blade bodies in the extension direction of the pipe. Effect of the Invention

[0007] An object of the present invention is to provide a heat exchanger in which the heat exchange efficiency is improved by turbulence of the fluid. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a partially cutaway view showing a schematic diagram of a heat exchanger according to an embodiment; [Diagram 2] FIG. 2 is a perspective view of the blade shown in FIG. [Diagram 3] A plan view of the blade shown in FIG. [Figure 4] Cross-sectional view taken along line IV-IV in Figure 3. [Diagram 5] End view of the piping as seen from the VV line shown in Figure 1 [Figure 6] FIG. 1 is a diagram for explaining the cross-sectional shape of a rib provided on a pipe; [Figure 7] FIG. 13 is a schematic diagram for explaining the shape of a rib in a heat exchanger according to a first modified example. [Figure 8] FIG. 13 is a schematic diagram showing a heat exchanger according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Embodiment) FIG. 1 is a partially cutaway view that illustrates a heat exchanger according to an embodiment.

[0010] The heat exchanger 100 includes a pipe 1 and a plurality of blades 2 provided in the pipe 1. The heat exchanger 100 according to the present embodiment can be applied to heat exchangers of various structures, such as a shell-and-tube heat exchanger in which the pipe 1 is housed inside the shell, a fin-tube heat exchanger in which fins are attached to the outer surface of the pipe 1, a double-tube heat exchanger in which the pipe 1 is housed in an outer tube, an air-cooled heat exchanger in which a fan is provided in a fin-tube heat exchanger, and a coil-type heat exchanger in which the pipe 1 is wound in a coil shape. Although not shown in FIG. 1, structures such as a shell, an outer tube, and fins are appropriately provided depending on the structure of the heat exchanger to be applied.

[0011] The pipe 1 is a member in which a first fluid flows and exchanges heat with a second fluid outside the pipe 1, and has a straight portion and a bent portion. The first fluid and the second fluid may be either a gas or a liquid. In other words, possible combinations of the first fluid and the second fluid include a combination of liquid and liquid, a combination of gas and gas, a combination of liquid and gas, and a combination of gas and liquid.

[0012] 2 is a perspective view of the blade shown in FIG. 1, FIG. 3 is a plan view of the blade shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG.

[0013] The vane bodies 2 are provided at two or more locations in the pipe 1 at intervals, and are components that swirl the first fluid flowing in the pipe 1 around the axial direction of the pipe 1 to generate a swirling flow of the first fluid. Adjacent vane bodies 2 are arranged at a predetermined interval in the extension direction of the pipe 1. A plurality of vane bodies 2 may be arranged continuously with no intervals and with the rotational positions shifted by a predetermined rotation angle, but by providing an interval between adjacent vane bodies 2, pressure loss can be reduced. The vane body 2 has a circular core 5, a cylindrical peripheral wall 6 that surrounds the core 5 with a predetermined interval between the outer peripheral surface of the core 5, and a plurality of blades 7 that are provided to bridge the outer peripheral surface of the core 5 and the inner peripheral surface of the peripheral wall 6. As shown in Figures 2 and 3, each of the blades 7 is arranged at an angle with respect to the central axis AX of the core 5, and swirls the fluid flowing in the space between the outer peripheral surface of the core 5 and the inner peripheral surface of the peripheral wall 6 around the central axis AX of the core 5. Specifically, as shown in Fig. 4, each of the blades 7 is inclined so that the vertical distance from a plane P including the upstream surface of the core 5 to the surface of the blade 7 (upstream surface) increases toward the swirling direction of the first fluid (in this embodiment, the counterclockwise direction around the central axis AX of the core 5 when viewed from the upstream side) (Fig. 6). The inclination angle of each of the blades 7 is constant. The multiple vane bodies 2 are configured to swirl the first fluid in the same direction.

[0014] In this embodiment, as shown in FIG. 4, the blade 7 has a flat main surface portion 13 and a bent portion 14 provided along the downstream edge of the main surface portion 13. The upstream edge of the main surface portion 13 is preferably formed in a thin blade shape to reduce fluid resistance. The bent portion 14 generates turbulence (vortex) in the fluid flowing along the downstream surface of the blade 7. The turbulence generated by the bent portion 14 can improve the heat transfer efficiency. The bent portion 14 of the blade 7 may be omitted, and the blade 7 may be configured to have only the function of swirling the first fluid. The number and inclination angle of the blades 7 are not particularly limited, and can be set based on the viscosity and flow rate of the fluid supplied to the heat exchanger 100, the pressure applied to the fluid, the allowable pressure loss, etc.

[0015] 1, three vane bodies 2 are provided on each straight section of the pipe 1, but the number of vane bodies 2 may be two or more. Vane bodies 2 may also be provided on the bent section of the pipe 1, but vane bodies 2 may not be provided on the bent section of the pipe 1 as in this embodiment, and vane bodies 2 may be provided on the front and rear portions of the bent section.

[0016] FIG. 5 is an end view of the piping as seen from the VV line shown in FIG.

[0017] A plurality of ribs 3 extending in the extension direction of the pipe 1 are provided on the inner peripheral surface of the pipe 1 of the heat exchanger 100 according to this embodiment, all around the circumference of the pipe 1. The ribs 3 need only be provided at least in the portion sandwiched between the two blade bodies 2 in the extension direction of the pipe 1, and for example, the ribs at the bent portion of the pipe 1 may be omitted, but as in this embodiment, the ribs 3 may be provided on the entire pipe 1. The pipe 1 having the ribs 3 can be integrally formed, for example, by extrusion molding of a metal material.

[0018] FIG. 6 is a diagram for explaining the cross-sectional shape of a rib provided on a pipe, showing a cross section along a plane perpendicular to the extension direction of the rib.

[0019] Each of the ribs 3 preferably has a substantially triangular cross section (transverse cross section) along a plane perpendicular to the extension direction. Each of the ribs 3 has two surfaces on the upper surface. Here, the surface of the rib 3 located upstream of the ridge line 8 in the swirling direction of the first fluid is the first surface 9, and the surface located downstream of the ridge line 8 in the swirling direction of the first fluid is the second surface 10. Both the first surface 9 and the second surface 10 may be flat or curved. FIG. 6(a) shows an example of a rib 3 in which both the first surface 9 and the second surface 10 are flat. FIG. 6(b) shows an example of a rib 3 in which both the first surface 9 and the second surface 10 are flat. FIG. 6(c) shows an example in which the first surface 9 is curved and the second surface 10 is flat. It is preferable to make the first surface 9 a curved surface because it can reduce pressure loss. When the first surface 9 and the second surface 10 are curved surfaces, concave surfaces are preferable. Moreover, it is preferable that the cross-sectional shape of the rib 3 in the vicinity of the ridge line 8 is angular.

[0020] The first fluid supplied to the pipe 1 passes between the blades 7 provided between the core 5 of the impeller body 2 and the peripheral wall 6 and flows downstream. At this time, the blades 7 are inclined, so that a swirling flow is generated in the first fluid. When a swirling flow is generated, centrifugal force acts on the first fluid. After the first fluid flows along the first surface 9 of the rib 3 of the peripheral wall 6, when the first fluid passes over the ridge line 8, a turbulent flow (vortex) is generated due to the step formed by the second surface 10. The centrifugal force generated by the swirling acts on the first fluid flowing near the rib 3, so that the turbulent flow generated in the part beyond the ridge line 8 of the rib 3 is also strong. Therefore, the multiple ribs 3 provided on the inner peripheral surface of the pipe 1 can promote the generation of turbulent flow and improve the heat transfer efficiency.

[0021] Here, assuming that the minimum width of the first surface 9 of the rib 3 is W1 and the minimum width of the second surface is W2, it is preferable to satisfy the relationship W1>W2, and more preferably to satisfy the relationship W1>1.5W2. When W1 is larger than W2, the first fluid can be sufficiently accelerated along the first surface 9, so that a turbulent flow can be effectively generated when the first fluid passes over the ridge line 8. The minimum width of the first surface 9 and the second surface 10 refers to the distance between both ends of the outline of the first surface 9 and the second surface 10 on the cross section of the rib 3 along a plane perpendicular to the extension direction of the rib 3 (when the rib 3 is formed in a spiral shape as in the modified example 1 described later, a plane perpendicular to the tangent at any point on the ridge line of the rib 3).

[0022] As described above, the heat exchanger 100 according to this embodiment includes two or more blade bodies 2 that swirl the first fluid flowing through the pipe 1. By swirling the first fluid with the blade bodies 2, the passage length of the first fluid can be increased, and therefore the contact time of the first fluid with the outer peripheral wall of the pipe 1 per flow rate is increased. This increases the amount of heat transfer from the first fluid to the pipe 1, and improves the heat exchange efficiency between the first fluid and the second fluid.

[0023] Furthermore, a plurality of ribs 3 extending in the extension direction of the pipe 1 are provided on the inner peripheral surface of the pipe 1. When the swirling flow of the first fluid collides with the ribs 3, turbulence occurs, which also increases the amount of heat transfer and improves the heat exchange efficiency. In particular, when the cross section of the ribs 3 is substantially triangular as in this embodiment, pressure loss is reduced while turbulence is likely to occur in the portion beyond the ridgeline of the ribs 3, which further improves the heat exchange efficiency.

[0024] (Variation 1) In the above embodiment, an example in which a plurality of ribs 3 are provided so as to extend along the extension direction of the pipe 1 has been described. However, the ribs 3 may be formed as in the following modified example 1.

[0025] Fig. 7 is a schematic diagram for explaining the shape of ribs in a heat exchanger according to Modification 1. Fig. 7 is a schematic diagram showing the relationship between the direction in which a first fluid flows in pipe 1 and the positions of the ridges of multiple ribs. In Fig. 7, a thick curved line represents the direction in which the first fluid flows, and a thin curved line represents the positions of the ridges of multiple ribs. Fig. 7 corresponds to a view of pipe 1 seen transparently from the outside of the side, with the solid curved line portion corresponding to the front side of pipe 1 and the dashed curved line portion corresponding to the back side of the pipe (the side opposite to the side being viewed).

[0026] In the first modification, the plurality of ribs 3 are formed such that the ridgeline of each extends along a spiral in the opposite direction to the swirling direction of the first fluid. The spiral period of the ribs 3 is preferably set so that the ridgeline of the ribs 3 and the swirling direction of the first fluid are approximately perpendicular to each other. By configuring the ribs 3 to extend in a spiral shape in the opposite direction to the swirling direction of the first fluid in this manner, the swirling flow of the first fluid can be caused to collide with the ribs 3 at a constant angle (e.g., approximately 90 degrees), so that a turbulent flow can be stably generated throughout the entire pipe 1, and the annual exchange efficiency can be further improved.

[0027] (Variation 2) FIG. 8 is a diagram illustrating a heat exchanger according to the second modification.

[0028] The heat exchanger according to the second modification is the heat exchanger 100 according to the above embodiment, with a plurality of fins 16 provided on the outer surface of the pipe 1. By providing the fins 16, it is possible to improve the heat exchange efficiency between the first fluid and the second fluid. In the heat exchanger according to the second modification, it is preferable to provide ribs 3 in the portion where the fins 16 are provided in order to improve the heat exchange efficiency.

[0029] (Other variations, etc.) In the above embodiment, an example in which the present invention is applied to a heat exchanger has been described, but it is also possible to configure a piping component that includes a piping having the above-mentioned ribs and a blade body. [Industrial Applicability]

[0030] The present invention can be used in a heat exchanger. [Explanation of symbols]

[0031] 1 Piping 2. Wing body 3. Ribs 8 Ridgeline 9. First Side 10 The Second Side 100 heat exchanger

Claims

1. 1. A heat exchanger comprising: A pipe for performing heat exchange between a first fluid flowing inside and a second fluid outside; a plurality of vanes provided at two or more locations in the pipe to swirl the first fluid around the axial direction of the pipe; A heat exchanger, wherein a portion of the pipe that is sandwiched between at least two of the blade bodies in the extension direction of the pipe is provided on an inner surface thereof with a plurality of ribs extending in the extension direction of the pipe.

2. The heat exchanger according to claim 1 , wherein a cross section of each of said ribs taken along a plane perpendicular to the extension direction thereof is substantially triangular.

3. The heat exchanger according to claim 2 , wherein a ridge line of each of the ribs extends in an extension direction of the pipe.

4. The heat exchanger of claim 2 , wherein the ridge of each of the ribs extends along a spiral in a direction opposite to a swirling direction of the first fluid.

5. 3. The heat exchanger of claim 2, wherein each of the ribs has a first surface located upstream of a ridge line in the swirling direction of the first fluid and a second surface located downstream of the ridge line in the swirling direction of the first fluid, and one or both of the first surface and the second surface are curved.

6. 6. The heat exchanger of claim 5, wherein the minimum width of the first surface is greater than 1.5 times the minimum width of the second surface.

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