JP2014005990A - Heat exchanger and heat pump water heater including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that promotes turbulence of a fluid flowing between an inner pipe and an outer pipe to improve heat exchange performance.SOLUTION: A heat exchanger includes an inner pipe 13 in which a first fluid flows and which comprises a plurality of pipes formed into a spiral shape, and an outer pipe 11 in which a second fluid flows. In the heat exchanger, the inner pipe 13 is arranged in the outer pipe 11, a plate-like member 18 through which the inner pipe 13 is passed is included, and a slewing part 19 is provided on the outer periphery of the plate-like member 18. Not only in the vicinity of the inner pipe formed into the spiral shape, but also in a place in which the gap between the inner pipe 13 and the outer pipe 11 becomes large, turbulence of the second fluid makes promoted, and heat transmission on the second fluid side can be improved.

Description

  The present invention relates to a double-tube heat exchanger having an inner pipe having a flow path through which a fluid passes and an outer pipe provided outside the inner pipe and having a flow path through which the fluid passes between the inner pipe and the inner pipe. It is.

  Conventionally, this type of heat exchanger is composed of a water pipe that constitutes a water flow path and a refrigerant pipe that constitutes a refrigerant flow path, and is a dual type that exchanges heat between water flowing through the water flow path and refrigerant flowing through the refrigerant flow path. A pipe-type heat exchanger has been devised (see, for example, Patent Document 1).

  As shown in FIGS. 10 to 12, the conventional heat exchanger double-tube heat exchanger includes a double tube in which a plurality of double tubes 102 formed in a spiral shape are connected. From the water pipe 106 in which the water pipe 105 is formed between the refrigerant pipe 104 having the refrigerant pipe 103 inside the double pipe 102 and the outer wall of the refrigerant pipe 104 by inserting the refrigerant pipe 104. Become.

  The refrigerant flow path 103 and the water flow path 105 are opposed to each other. As a result, the heat exchange efficiency can be improved.

  Further, the double pipe 102 has an intermediate header 107 as a boundary, and the upstream side of the refrigerant is an upstream double pipe, and the downstream side of the refrigerant is a downstream double pipe.

  The refrigerant pipe 104 includes two high-temperature section refrigerant pipes 104 a disposed on the inlet side of the refrigerant flow path 103 and four low-temperature section refrigerant pipes 104 b provided on the outlet side of the refrigerant flow path 103. The diameter of the water pipe that encloses the high temperature part refrigerant pipe 104a is larger than the diameter of the water pipe that encloses the low temperature part refrigerant pipe 104b.

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

  The heat exchanger 101 is formed by a double pipe of the refrigerant pipe 103 and the water pipe 105, and exchanges heat between the water and the refrigerant, so that the inner pipe 103 can have a large contact area with water and improve the heat exchange efficiency. it can.

  Further, as shown in FIG. 12, the two refrigerant tubes 103 are inserted in the water tube 105 so as to be intertwined in a spiral shape. Thereby, the water flow in the vicinity of the refrigerant pipe 103 is turned into a swirl flow, and the water-side heat transfer coefficient is improved.

  Further, the diameter of the water pipe containing the high-temperature part refrigerant pipe 104a is increased because impurities such as calcium carbonate are deposited from the high-temperature water, adhere between the refrigerant pipe 103 and the water pipe 105, and fill the gap. This is in order not to be stupid.

JP 2005-69620 A

However, when the two inner pipes are twisted together as in the conventional case, the water flow in the vicinity of the two inner pipes becomes a swirl flow, but the location where the clearance between the inner pipe and the water pipe is large, particularly in the high temperature section In a pipe having a diameter increased to, the effect of promoting the turbulence of the water flow is reduced.

  The present invention solves the above-described conventional problems, and provides a heat exchanger with improved heat exchange performance by promoting turbulence of a fluid flowing between an inner tube and an outer tube. Objective.

  In order to solve the above-described conventional problems, a heat exchanger according to the present invention includes an inner pipe made of a plurality of pipes formed by twisting a first fluid and a second fluid flowing therethrough. The inner pipe is disposed in the outer pipe, has a plate-like member through which the inner pipe penetrates, and is provided with a swivel portion on the outer periphery of the plate-like member. Promotes turbulence and improves heat transfer.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger which improved heat exchange performance can be performed by accelerating | stimulating the turbulent flow of the fluid which flows between an inner tube | pipe and an outer tube | pipe.

Side view of double-pipe heat exchanger in Embodiment 1 of the present invention Top view of the double-pipe heat exchanger Detailed cross-sectional view of the inside of the double-pipe heat exchanger Other internal detailed sectional view of the double-pipe heat exchanger Front view of the plate-like member of the double pipe heat exchanger Detailed sectional view of the interior of a conventional double tube heat exchanger Other internal detailed sectional view of the double-pipe heat exchanger Other internal detailed sectional view of the double-pipe heat exchanger Diagram showing temperature change of carbon dioxide and water in the heat exchanger Side view of conventional heat exchanger Top view of conventional heat exchanger Internal sectional view of conventional heat exchange

  A first invention includes an inner tube made of a plurality of pipes formed by spirally twisting and flowing a first fluid, and an outer tube through which a second fluid flows, and the inner tube is disposed in the outer tube. The heat exchanger has a plate-like member through which the inner tube passes, and a swivel part is provided on the outer periphery of the plate-like member.

  As a result, not only in the vicinity of the inner pipe formed by twisting spirally, but also in a place where the gap between the inner pipe and the outer pipe is large, turbulence of the second fluid is promoted, and heat transfer on the second fluid side is promoted. It becomes possible to improve.

  In a second aspect of the present invention, the second fluid flows in the twist direction of the inner tube by the swivel unit.

  Thereby, a swirl flow can be enlarged without obstructing the flow of the second fluid in the vicinity of the inner tube, and the turbulence of the second fluid can be promoted.

  The third invention is characterized in that a larger number of the plate-like members are provided on the downstream side than the upstream side in the flow direction of the second fluid.

Thereby, when the first fluid of the heat exchanger is carbon dioxide and the second fluid is water, the temperature change of each fluid has a large temperature difference between carbon dioxide and water at the inlet / outlet of the heat exchanger. Since the temperature difference is small at the center, the temperature difference is large as at the entrance and exit of the heat exchanger. It can be improved effectively.

  In particular, in the water-carbon dioxide heat pump water heater, since the diameter of the high-temperature part of the heat exchanger is expanded as a measure against scale, the gap between the inner pipe and the water pipe is large, and the flow velocity of water is reduced. That is, in the flow of the second fluid, it is more effective to provide more plate-like members on the downstream side than on the upstream side.

  4th invention mounts the heat exchanger of any one of 1st to 3rd invention in a heat pump water heater, and can improve the capability of a heat pump water heater.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the heat exchanger is a carbon dioxide-water heat exchanger used in a heat pump water heater, and the first fluid is carbon dioxide and the second fluid is water.

  As shown in FIGS. 1 and 2, in the present embodiment, the heat exchanger 1 has a plurality of heat exchange units 6 in which a double pipe 5 is formed in a spiral shape. In the heat exchange unit 6 on the side, the water flow path 12 is joined by the intermediate header 3, and the refrigerant flow path 15 is joined by the refrigerant branch pipe 7.

  The header 2 is provided with a refrigerant header 8, a water pipe 9, a refrigerant branch pipe 10, and the header 4 is provided with a water pipe 8 and a refrigerant branch pipe 9, which are joined to attach the heat exchanger 1 to the water heater main body. Has been.

  As shown in FIG. 3, a coolant channel 15 is formed in the inner tube 13, and a water channel 12 is formed between the inner tube 13 and the outer tube 11. And the refrigerant | coolant which distribute | circulates the flow path 15 for refrigerant | coolants, and the water which distribute | circulates the flow path 12 for water flow so as to oppose each other, As a result, the heat exchange efficiency between a refrigerant | coolant and water is improved. Can do.

  The inner tube 13 includes a refrigerant tube 14 and a leak detection tube 16 provided on the outer periphery of the refrigerant tube 14, and the two inner tubes 13 are arranged in parallel in the vertical direction. A large number of leak detection grooves 17 are formed on the inner surface of the leak detection pipe 16 along the piping direction, and an air layer is formed in the leak detection groove 17.

  By providing the leak detection groove 17, the refrigerant or water leaked from the inner tube 13 or the outer tube 11 leaks outside through the leak detection groove 17 without mixing.

  In the present embodiment, the plate-like member 18 is provided only at a location where the outer tube 11 of FIG. With such a configuration, it is possible to promote the turbulent flow of water where the inner diameter is increased and the water flow velocity is decreased, and the ability of the heat exchanger 1 can be effectively improved.

  Further, if the plate-like member 18 is provided in the entire area of the inner pipe 13, the turbulence of the flow is promoted and the capacity of the heat exchanger 1 is improved, but the pressure loss is also increased. The power of a device such as a simple pump increases.

  Therefore, if priority is given to improving the capacity of the heat exchanger 1, it is better to provide the plate-like member 18 over the entire inner tube 13, but if considering the linkage with other devices, the plate-like member 18 is In the water flow direction, it is better to provide more on the downstream side than on the upstream side.

  That is, FIG. 9 shows the temperature change of each fluid when the first fluid is carbon dioxide and the second fluid is water, but the temperature difference between carbon dioxide and water is large at the entrance and exit of the heat exchanger. This is because the temperature difference is small at the center of the heat exchanger, so that the capacity of the heat exchanger can be effectively improved.

  4 and 5 are views showing the shape of the plate member 18. In the present embodiment, a hole having a shape in which two inner pipes 13 are twisted is formed in the plate-like member 18, and a turning portion 19 is provided around the plate-like member 18.

  When the water flowing in the vicinity of the inner pipe 13 comes into contact with the plate-like member 18, the water is guided to the swivel portion 19 and flows between the outer pipe 11 and the inner pipe 13 as a larger swirl flow. .

  Further, the swivel part 19 of the plate-like member 18 has the blade root arranged in front of the plate-like member, and the wing tip is arranged downstream of the plate-like member 18 with respect to the flow of water so that the water is plate-like. It is configured not to stop water when it collides with the member 18.

  For example, the broken line portion in FIG. 6 shows the trajectory of the two twisted inner tubes 13 with respect to the direction of water flow, but the clearance between the outer tube 11 and the inner tube 13 is large. Only water near the inner pipe can be swirled.

  However, if the plate-like member 18 is provided, the clearance between the inner tube 13 and the outer tube 11 is narrowed, and water is supplied to the outer tube 11 and the inner tube 13 by the swiveling part 19 provided in the same twisting direction as the inner tube 13. It flows as a large swirl between them, improving water heat transfer.

  Further, as shown in FIGS. 7 and 8, the water in the vicinity of the inner tube 13 flows along the twisting direction of the inner tube 13 to form a swirling flow, and therefore collides with the plate-like member 18 and the swiveling portion 19. Even so, the water will not stop.

  Further, the swivel unit 19 is twisted in the same twisting direction as the inner tube 13, and the water flow colliding with the swivel unit 19 flows so as to be largely twisted toward the wing tip of the swivel unit 19, and the wing tip is Since it comes out downstream with respect to the flow direction of water rather than the plate-shaped member 18, water flows also into the back side of the plate-shaped member 18, and the amount of heat exchange between water and carbon dioxide does not decrease.

  Further, in the present embodiment, the plate-like member 18 is expanded by being brazed to the outer wall of the inner tube 13 or by applying pressure in the inner tube 13 and fixed in close contact.

  If the plate-like member 18 is formed of a metal material, heat conduction from the inner tube 13 makes it possible to transfer heat not only to the water around the inner tube 13 but also to the water around the plate-like member 18. The amount of heat exchange of carbon dioxide can be increased.

  As described above, in the present embodiment, the two inner pipes 13 twisted in a spiral shape are attached to the plate-like member 18 by paying attention to the temperature difference between carbon dioxide and water in the heat exchanger 1 and water pressure loss. By making it penetrate, the capability of the heat exchanger 1 can be improved.

  As described above, the heat exchanger according to the present invention can improve the heat exchange performance by promoting the turbulent flow of the fluid flowing between the inner tube and the outer tube, so that heat exchange is performed between the fluids. Applicable to equipment with functions.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 11 Outer tube 13 Inner tube 18 Plate-shaped member 19 Turning part

Claims (4)

A first fluid flows and includes an inner tube made of a plurality of pipes formed by twisting spirally, and an outer tube through which a second fluid flows. The inner tube is disposed in the outer tube, and the inner tube passes therethrough. A heat exchanger having a plate-like member to be provided, and a swivel portion provided on an outer periphery of the plate-like member. 2. The heat exchanger according to claim 1, wherein the second fluid flows in a twisting direction of the inner pipe by the swivel unit. 3. The heat exchanger according to claim 1, wherein a larger number of the plate-like members are provided on the downstream side than the upstream side in the flow direction of the second fluid. A heat pump water heater equipped with the heat exchanger according to any one of claims 1 to 3.