JP2007093082A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger having improved long-time reliability by suppressing choke of scales in an arbitrary section without lowering its performance. <P>SOLUTION: In the heat exchanger, water flows in an inner tube 2 and carbon dioxide flows in opposition thereto in an annular portion between the inner tube 2 and an outer tube 4, and a safe double-wall is provided for securing a sufficient contact area to produce high heat exchanging efficiency. When scales are deposited on a wall face 2a of the inner tube 2, a bias coil 9 is slid almost parallel to the wall face 2a in linkage with the elongation of a spiral wire rod 8 of a shape memorizing alloy having a deforming temperature or higher to scrape off the scales. The bias coil 9 can be slid to an arbitrary section with its selective movable width set by adjusting the length of the spiral wire rod 8 in the direction of the tube axis. This simple construction improves long-time reliability of the heat exchanger while automatically suppressing the lowering of the performance of the heat exchanger due to choke of the scales in the arbitrary section with the arbitrary movable width and the closure of a water flow path. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger that performs heat exchange between water and a refrigerant in a heat pump type hot water heater, an air conditioner for home use, and for business use.

  Conventionally, when this type of heat exchanger is used, hardness components such as calcium and magnesium in water gradually deposit, adhere and accumulate in the water-side flow path as a scale (for example, calcium carbonate). When the scale accumulates on the wall where heat is exchanged, it becomes a thermal resistance, reducing the heat exchange performance, increasing the flow path resistance, decreasing the flow rate of the pressure pump water for flowing water, There is a problem that the road is blocked and the product does not function. Since the precipitation of calcium carbonate increases extremely when water becomes hot, scale tends to deposit on the high temperature side of the heat exchanger. For this reason, there is one in which the cross-sectional area of the water-side channel on the downstream side of the high temperature that is easily scaled is increased (see, for example, Patent Document 1).

  Moreover, there exists what was equipped with the scale removal means (for example, refer patent document 2) as scale adhesion prevention in a pipe.

  Patent Document 2 describes a liquid heating apparatus provided with a scale adhesion preventing means in a pipe. As a scale adhesion preventing method, it is disclosed that the movable means slides in accordance with the temperature change in the pipe by the movable means combining the shape memory coil and the bias spring, and the scale is removed. However, the heat exchanger that exchanges heat between water and the refrigerant is different from the basic structure, and a description of a limited structure for a heat source that heats water has not been made.

  FIG. 6 is a partial cross-sectional view of a conventional heat exchanger described in Patent Document 1.

  The heat exchanger 100 includes a water pipe 101, a refrigerant pipe 102, a water connection pipe 103, and a refrigerant connection pipe 104, and the water pipe 101 uses a pipe having a diameter larger than that of the upstream side on the downstream side.

  The operation of the heat exchanger 100 configured as described above will be described below.

Usually, the water pipe 101 and the refrigerant pipe 102 exchange heat and warm low-temperature water with heat from the high-temperature refrigerant. Even if scale is deposited in the water pipe 101, the downstream side has a large flow path, so that it flows smoothly. In addition, it took time to adhere and become tangled, extending the life of the heat exchanger.
JP 2004-093037 A JP-A-8-185961

  However, in the configuration of the heat exchanger 100 described in the above-described conventional Patent Document 1, when the water-side flow path is increased, the flow rate of water is reduced, so that the heat exchange performance is deteriorated.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to suppress the scale clogging of an arbitrary section without lowering the heat exchanger performance and to improve the long-term reliability of the heat exchanger.

  In order to solve the above-described conventional problems, a heat exchanger according to the present invention includes a first flow path in which a first fluid and a second fluid flow in a tubular body or a housing so as to allow heat exchange with each other, and A second flow path; and a movable means that moves in the first flow path. The movable means includes a first drive section and a second drive section. The second drive unit moves in conjunction with the drive unit, and the second drive unit moves in the vicinity of the wall surface of the first flow path substantially parallel to the wall surface. is there.

  As a result, when the first fluid is water, the scale attached to the wall surface of the first flow path is moved by the second drive unit of the movable means moving substantially parallel in the first flow path. This is peeled off by sliding of the driving portion to prevent the scale from adhering to the wall surface of the first flow path. Also, since the second drive unit is moved by operating the first drive unit, the length of the first drive unit in the tube axis direction is adjusted to set an arbitrary movable width and remove the scale The second drive unit can be moved to any desired section.

  The heat exchanger of the present invention can suppress deterioration of heat exchanger performance and blockage of the water flow path due to the scale of an arbitrary section with an arbitrary movable width, and can improve the long-term reliability of the heat exchanger.

  The invention according to claim 1 includes a first flow path and a second flow path in which a first fluid and a second fluid flow in a tubular body or a housing so as to exchange heat with each other; Movable means that moves in one flow path, and the movable means includes a first drive unit and a second drive unit, and the first drive unit interlocks with the first drive unit. The second drive unit moves, and the second drive unit moves in the vicinity of the wall surface of the first flow path substantially parallel to the wall surface.

  As a result, when the first fluid is water, the scale attached to the wall surface of the first flow path is moved by the second drive unit of the movable means moving substantially parallel in the first flow path. This is peeled off by sliding of the driving portion to prevent the scale from adhering to the wall surface of the first flow path. In addition, since the second drive unit is moved by operating the first drive unit, it is desired to adjust the length of the first drive unit in the tube axis direction to set an arbitrary movable width and remove the scale. Move the second drive part to an arbitrary section, suppress the deterioration of the heat exchanger performance due to the scale of the arbitrary section with an arbitrary movable width, blockage of the water flow path, and improve the long-term reliability of the heat exchanger Can be increased.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the length of the first drive unit in the tube axis direction is shorter than that of the second drive unit.

  As a result, especially when the first drive unit is located at the center of the first flow path, the flow path wall surface is the slowest and the center is the fastest in the first fluid flow rate distribution. By shortening the means, it is possible to effectively suppress an increase in flow resistance due to the first drive unit and to suppress an increase in flow resistance due to insertion of the movable means.

  According to a third aspect of the present invention, in the first aspect of the present invention, the length of the first drive unit in the tube axis direction is longer than that of the second drive unit.

  As a result, the load on the first drive unit during movement due to the frictional resistance between the second drive unit and the wall surface can be kept small, and the movable life of the movable means can be extended.

  According to a fourth aspect of the present invention, in the first aspect of the invention according to any one of the first to third aspects, the first driving unit includes a temperature detection unit of the first fluid, and the temperature detection unit. The maximum dimension in the direction perpendicular to the tube axis of the first flow path is made smaller than that of the second drive unit.

  As a result, in the first flow path, the temperature distribution of the first fluid in the direction perpendicular to the tube axis is lower in the center of the flow path than the vicinity of the wall surface, which is the heat transfer surface, and is difficult to scale. By arranging the first drive unit having the temperature detection means in the center of the flow path, the adhesion of the scale that becomes the thermal resistance to the temperature detection means is suppressed, and the temperature responsiveness of the temperature detection means is reduced. Deterioration can be prevented and the long-term reliability of the heat exchanger can be enhanced.

  The invention according to claim 5 is the invention according to claim 4, wherein the temperature detecting means is inserted on a high temperature side of the first fluid subjected to heat exchange.

  Thereby, the temperature change of the first fluid during the product operation and the operation stop is large on the high temperature side of the heat exchanged first fluid, and the temperature response of the temperature detection means is more reliably obtained. Automatic removal can be reliably performed to increase the long-term reliability of the heat exchanger.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the first flow path is an inner tube, and an outer periphery of the inner tube is covered and is in close contact with the inner tube. It is installed so as to cover the outer periphery of the intermediate tube and the intermediate tube, and has an annular portion as the second flow path between the intermediate tube and the second fluid is the first fluid in the annular portion And an outer tube that flows in opposition to each other, and is constituted by a multiple tube.

  This provides a very simple configuration with a double wall that ensures safety between the first fluid and the second fluid, with sufficient contact between the first and second channels. It is possible to secure an area, reduce the fluid diameter of the second fluid at the annular portion, promote heat transfer, and obtain high heat exchange efficiency as a heat exchanger.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the second drive unit and the first flow path are made of the same material. Is.

  Thereby, even when the second drive unit and the first flow path are in contact with each other, since the same material is used, electrolytic corrosion can be prevented and the long-term reliability of the heat exchanger can be improved.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the first driving section is formed of a temperature-dependent elastic member. It is.

  As a result, the temperature detection means and the first drive unit can be integrated, and scale adhesion can be automatically suppressed to a certain amount or less with a simple structure, and the long-term reliability of the heat exchanger can be improved.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the first fluid is water and the second fluid is carbon dioxide.

  As a result, high heat exchange efficiency can be obtained as a heat exchanger, and high heat exchange efficiency can be obtained as a product, particularly when used in a heat pump type water heater.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, the same reference numerals are given to the same components as those of the above-described embodiment, and the detailed description thereof is omitted. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view in the tube axis direction of the heat exchanger according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a state diagram showing a scale adhering state in the embodiment, and FIG. 4 is a state diagram showing a scale removing action in the embodiment.

  1 and 2, the heat exchanger main body 1X includes an inner tube 2 in which water flows, an inner tube 3 that covers the outer periphery of the inner tube 2 and is partially adhered to the inner tube 2, and an inner tube 3 The outer tube 4 that forms an annular portion 4a that flows in opposition to the water that flows through the inner tube 2 between the inner tube 2 and the inner tube 3 that is locally in close contact with the outer tube. Tube 1. The middle tube 3 has a groove 5 that is partially adhered to the inner tube 2 on the inner wall. The outer tube 4 has a rib 6 that is in close contact with the middle tube 3 on the inner wall. A branch pipe 7 is attached to the pipe end of the triple pipe 1. The pipe end of the outer pipe 4 is provided inside the branch pipe 7 and the inner pipe 2 and the middle pipe 3 are penetrated to separate the water and carbon dioxide outlets. The tube end of the intermediate tube 3 penetrating the branch tube 7 is shorter than the inner tube 2 to allow the groove 5 to communicate with the atmosphere. The inner tube 2, the middle tube 3, and the outer tube 4 are made of copper having good corrosion resistance and thermal conductivity.

  Inside the inner tube 2, as a movable means, a spiral wire 8 made of a shape memory alloy that expands and contracts depending on the temperature as the first drive unit, and is connected to the spiral wire 8 and faces one end of the spiral wire 8. It has a copper bias coil 9 which is a second drive unit having a stress relationship. The spiral wire 8 and the bias coil 9 act so as to press each other. The spiral wire 8 is inserted into the water outflow side 2b of the inner tube 2 where heat is exchanged and becomes hot, and the length in the tube axis direction is shorter than that of the bias coil 9 and is perpendicular to the tube axis direction. The diameter of the spiral winding in the direction is also small and located in the center of the flow path. The bias coil 9 is located near the wall surface 2 a of the inner tube 2. Here, the shape memory alloy is a Ti-Ni alloy having excellent heat resistance and corrosion resistance, and has a property of returning to a shape before deformation when the plastically deformed alloy is heated to a certain deformation temperature or higher.

  About the heat exchanger 1X comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, water flows inside the inner tube 2, carbon dioxide flows through the annular portion 4 a between the inner tube 3 and the outer tube 4, and a double wall between the inner tube 2 and the inner tube 3 is formed. Through this, water and carbon dioxide exchange heat.

  Here, the fluid diameter of the carbon dioxide is reduced by the annular portion 4a so that a double wall is formed between the inner tube 2 and the middle tube 3, so that the thermal resistance between water and carbon dioxide is low and sufficient contact is achieved. Secure the area. Further, by adopting a double wall structure having a groove 5 between water and carbon dioxide, when one pipe corrodes, leakage of the internal fluid is detected by the groove 5 of the middle pipe 3 communicating with the atmosphere.

  Further, as shown in FIGS. 3 and 4, the temperature of the water rises due to heat exchange with the carbon dioxide in the annular portion 4 a, and calcium contained in the water (particularly tap water) precipitates to cause the wall surface 2 a of the inner tube 2. Even if the scale adheres, the water temperature rises and the helical wire 8 becomes higher than the deformation temperature, so that the stress of the bias coil 9 is extended and the bias coil 9 is contracted in conjunction with the helical wire 8 and the wall surface Since the scale is peeled off by sliding substantially parallel to 2a, an arbitrary movable width is set by adjusting the length of the spiral wire 8 in the tube axis direction, and the bias coil 9 is slid to an arbitrary section. In addition, the temperature detecting means and the movable means can be integrated. Therefore, scale adhesion is automatically suppressed to a certain amount or less with an arbitrary movable width in an arbitrary section, and the blockage of the inner tube 2 is prevented.

  Further, the spiral wire 8 has a shorter length in the tube axis direction than the bias coil 9 and a smaller spiral winding diameter, so that the spiral in the central portion of the flow path where the flow rate of water is the fastest and the most flow rate flows. An increase in flow resistance due to the wire 8 is effectively suppressed. Furthermore, by arranging the spiral wire 8 in the center of the flow path with a reduced spiral winding diameter, a wall surface in which the temperature distribution of water in the direction perpendicular to the tube axis is the heat transfer surface in the inner tube 2 Since it is lower than the vicinity of 2a in the center of the flow path and is difficult to scale, adhesion of the scale that becomes thermal resistance to the spiral wire 8 is suppressed, and deterioration of the temperature responsiveness of the shape memory alloy is prevented. . In addition, the amount of the shape memory alloy, which is generally expensive, is reduced to reduce the material cost.

  Further, by inserting the spiral wire 8 into the outflow side 2b of the inner pipe 2 where the heat is exchanged and becomes high temperature, the outflow side 2b has a large water temperature change during product operation and operation stop. Therefore, the temperature response of the helical wire 8 can be obtained more reliably.

  In addition, by making the wall surface 2a of the inner tube 2 and the material of the bias coil 9 which is the second drive unit made of the same copper, electrolytic corrosion due to contact of different metals is prevented.

  Moreover, high heat exchange efficiency is obtained as the heat exchanger 1X by using water as the first fluid and carbon dioxide as the second fluid.

  As described above, in the present embodiment, the triple pipe 1 in which the water flows inside the inner pipe 2 and the annular portion 4a between the middle pipe 3 and the outer pipe 4 flows in a manner that the carbon dioxide is opposed to each other. By reducing the fluid diameter of carbon dioxide by the annular portion 4a and forming a double wall between the inner tube 2 and the middle tube 3, the thermal resistance between water and carbon dioxide is low, and a sufficient contact area And high heat exchange efficiency can be obtained. Further, by adopting a double wall structure having a groove 5 between water and carbon dioxide, when one of the pipes corrodes, a structure for detecting leakage of the internal fluid at the groove 5 of the middle pipe 3 communicating with the atmosphere. Therefore, safety can be ensured between water and carbon dioxide.

  Even if the temperature of the water rises and the scale adheres to the wall surface 2 a of the inner tube 2, the spiral wire 8 becomes longer than the deformation temperature, and the bias coil 9 is contracted in conjunction with the spiral wire 8. Since the scale is peeled off by sliding substantially parallel to the wall surface 2a, an arbitrary movable width is set by adjusting the length of the spiral wire 8 in the tube axis direction, and the bias coil 9 is slid to an arbitrary section. Further, the temperature detecting means and the movable means can be integrated. Therefore, it is possible to improve the long-term reliability of the heat exchanger with a simple structure by automatically suppressing the deterioration of the heat exchanger performance and the blockage of the water flow path due to the scale of an arbitrary section with an arbitrary movable width.

  Further, the spiral wire 8 has a shorter length in the tube axis direction than the bias coil 9 and a smaller spiral winding diameter, so that the spiral in the central portion of the flow path where the flow rate of water is the fastest and the most flow rate flows. An increase in flow resistance due to the wire 8 can be effectively suppressed, and an increase in flow resistance due to insertion of the movable means can be suppressed. Furthermore, by arranging the spiral wire 8 in the center of the flow path with a reduced spiral winding diameter, a wall surface in which the temperature distribution of water in the direction perpendicular to the tube axis is the heat transfer surface in the inner tube 2 Since it is lower in the central part of the flow path than the vicinity of 2a and is difficult to scale, adhesion of the scale that becomes thermal resistance to the spiral wire 8 is suppressed, and deterioration of the temperature responsiveness of the shape memory alloy is prevented. Thus, the long-term reliability of the heat exchanger 1X can be improved. In addition, the amount of the shape memory alloy, which is generally expensive, can be reduced, the material cost can be reduced, and the movable means can be manufactured at a lower cost.

  Further, by inserting the spiral wire 8 into the outflow side 2b of the inner pipe 2 where the heat is exchanged and becomes high temperature, the outflow side 2b has a large water temperature change during product operation and operation stop. Therefore, the temperature response of the spiral wire 8 can be more reliably obtained, the scale can be automatically removed, and the long-term reliability of the heat exchanger can be improved.

  Furthermore, the wall surface 2a of the inner tube 2 and the material of the bias coil 9 that is the second drive unit are made of the same copper, so that there is no fear of galvanic corrosion due to contact of different metals, and the long-term reliability of the heat exchanger 1X Can be increased.

  Further, high heat pump efficiency can be obtained by using water as the first fluid, carbon dioxide as the second fluid, and using the heat exchanger 1X as a water-refrigerant heat exchanger for heat pump hot water heaters.

  In addition, in this Embodiment, although heat exchanger 1X whole was made into linear form, the same effect is acquired also in the form of a curve and a coil. Further, the inner tube 2, the middle tube 3, and the outer tube 4 may be formed integrally.

  In addition, the tubular body constituting the main body of the heat exchanger 1X is the triple pipe 1, but the present invention is not limited to this, and the first flow in which the first fluid and the second fluid flow inside each other so as to be able to exchange heat with each other. It is sufficient if it has a channel and a second channel and is rigidly integrated or in close contact. For example, various shapes such as a simple round tube overlapped as a water tube or a refrigerant tube (not shown) may be used. A similar effect can be obtained. The main body of the heat exchanger 1X may be a casing. For example, the water-side flow path as the first fluid is a box-shaped casing, and the second fluid is placed on the outer wall surface or the inner wall surface of the casing. It may be a tube (not shown) constituted by closely or integrally forming a pipe serving as a refrigerant passage or a porous body.

  In the present embodiment, the copper bias coil 9 is shown as the second drive unit. However, the present invention is not limited to this, and other metal springs, resin springs, or the like may be used.

  In the present embodiment, the material of the inner tube 2, the intermediate tube 3, and the outer tube 4 is usually made of copper, but the same effect can be obtained by using brass, SUS, corrosion-resistant iron, aluminum alloy, or the like.

  In the present embodiment, carbon dioxide is used as the refrigerant flowing through the annular portion 4a. However, similar effects can be obtained with a refrigerant that operates at a high pressure such as R410A.

  In the present embodiment, the spiral material 8 is a Ti—Ni alloy that is a shape memory alloy, but an alloy such as Cu—Zn or In—Ti has the same effect.

(Embodiment 2)
FIG. 5 is a cross-sectional view in the tube axis direction of the heat exchanger according to Embodiment 2 of the present invention.

  In FIG. 5, the spiral wire 8 of the movable means has a longer length in the tube axis direction than the bias coil 9.

  As a result, the load on the spiral wire 8 during sliding due to the frictional resistance between the bias coil 9 and the wall surface 2a is kept small.

  Therefore, the movable life of the movable means can be made longer.

  As described above, the heat exchanger according to the present invention can achieve high heat exchange efficiency at the same time with a very simple structure, and calcium is deposited and adhered to the inner wall of the outflow side where water flows. However, with a simple structure, scale adherence in any section with any movable width can be automatically suppressed to a certain amount or less, and blockage of the flow path can be prevented, improving the long-term reliability of the heat exchanger Therefore, it can be applied to uses such as heat pump water heaters, home and commercial air conditioners, and fuel cells.

Sectional drawing of the pipe-axis direction of the heat exchanger in Embodiment 1 of this invention AA line sectional view of FIG. State diagram showing scale adhesion state in the same embodiment State diagram showing scale removal effect in the same embodiment Sectional drawing of the pipe-axis direction of the heat exchanger in Embodiment 2 of this invention Partial sectional view of a conventional heat exchanger

Explanation of symbols

1X heat exchanger body 1 triple tube 2 inner tube 2a wall surface 2b outflow side 3 middle tube 4 outer tube 4a annular portion 8 spiral wire 9 bias coil

Claims (9)

  A first fluid channel and a second fluid channel in which a first fluid and a second fluid flow in a tubular body or a housing so as to be capable of exchanging heat with each other, and a movable fluid moving in the first fluid channel And the movable means is composed of a first drive unit and a second drive unit, and the second drive unit moves in conjunction with the first drive unit. The heat exchanger is characterized in that the second drive unit moves in the vicinity of the wall surface of the first flow path substantially parallel to the wall surface.   The heat exchanger according to claim 1, wherein a length of the first drive unit in a tube axis direction is shorter than that of the second drive unit.   2. The heat exchanger according to claim 1, wherein a length of the first driving unit in a tube axis direction is longer than that of the second driving unit.   The first drive unit includes a temperature detection unit of the first fluid, and operates based on detection of the temperature detection unit, and is in a direction perpendicular to the tube axis of the first flow path. 4. The heat exchanger according to claim 1, wherein the maximum dimension is smaller than that of the second drive unit. 5.   The heat exchanger according to claim 4, wherein the temperature detection means is inserted on a high temperature side of the heat-exchanged first fluid.   The first flow path is an inner tube, an inner tube that covers the outer periphery of the inner tube and is in close contact with the inner tube, and is installed so as to cover an outer periphery of the intermediate tube. 2. An annular portion as a second flow path, and a multiple tube comprising an outer tube in which the second fluid flows in opposition to the first fluid in the annular portion. To 5. The heat exchanger according to any one of 5 to 5.   The heat exchanger according to any one of claims 1 to 6, wherein the second drive unit and the first flow path are made of the same material.   The heat exchanger according to any one of claims 1 to 7, wherein the first driving unit is formed of a temperature-dependent elastic member.   The heat exchanger according to any one of claims 1 to 8, wherein the first fluid is water, and the second fluid is carbon dioxide.

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