JP6565426B2 - Multi-tube condensation heat exchanger - Google Patents

Description

  The present invention relates to a multi-tube condensing heat exchanger, and more particularly to a multi-tube condensing heat exchanger in which an elastic body is provided at the center of a multi-leaf tube forming an inner tube.

  Conventionally, hot water heated by a heat source device such as a gas combustion heat source device, a heat pump heat source device, a fuel cell power generation device, etc. is stored in a hot water storage tank and hot water is supplied to a desired hot water supply destination, and heated by the heat source device. Various heat exchangers for exchanging heat between a high-temperature fluid and a low-temperature fluid are widely used in heating devices that supply hot water to a heating terminal and other various industrial fields. Yes.

  In particular, the double-pipe heat exchanger has been widely adopted because it has excellent heat exchange performance and is advantageous in terms of production cost. Recently, the pipe wall as an inner pipe repeats crests and troughs in the circumferential direction. A double tube heat exchanger in which a multi-leaf tube having a corrugated shape is used and the multi-leaf tube is housed inside an outer tube is also employed.

  However, in a double-pipe heat exchanger used in a hot water storage and hot water supply device, for example, when a coolant flows in the inner pipe and hot water flows in a gap between the inner pipe and the outer pipe, a crack occurs in the inner pipe. There is a risk that the refrigerant leaks and enters the hot water.

  Therefore, in the triple-pipe heat exchanger disclosed in Patent Document 1, an inner pipe made of a corrugated multi-leaf pipe that alternately repeats crests and troughs in the circumferential direction has a double structure. The inner tube of the multi-leaf tube is housed in the outer tube so that the refrigerant flowing in the inner tube can be prevented from entering the hot water flowing between the inner tube and the outer tube.

  Further, in Patent Document 2, in a double-pipe heat exchanger having an inner tube and an outer tube, a heat transfer fin formed of a corrugated tube is in contact with the inner wall of the inner tube, The structure which provided the pillar which obstruct | occludes an inner pipe | tube center part inside is disclosed. The column body is a plastic body made of a heat-resistant ceramic or plastic in a cylindrical or prismatic shape.

  In this double pipe heat exchanger, high temperature gas is allowed to flow inside the inner pipe, and cooling water is allowed to flow between the outer pipe and the inner pipe, in order to increase the heat transfer efficiency from the high temperature gas to the inner pipe. The heat transfer fin is provided in the inner tube. Since the heat transfer area from the inner pipe to the cooling water is only the outer peripheral surface of the inner pipe, the heat exchange performance is not greatly improved.

Japanese Patent Laying-Open No. 2015-010757 Japanese Patent Laid-Open No. 11-183062

  In the triple-pipe heat exchanger described in Patent Document 1, the refrigerant flowing through the central portion of the multi-leaf tube forming the inner tube is not easily exchanged with hot water flowing between the inner tube and the outer tube. The performance is lowered and the charging amount of the refrigerant is increased.

  An object of the present invention is to provide a multi-tube condensing heat exchanger in which an elastic body is provided in the central portion of a multi-leaf tube forming an inner tube and closed so that no refrigerant flows through the central portion of the inner tube. .

The multi-tube condensing heat exchanger according to claim 1 includes an inner tube and an outer tube in which the inner tube is housed, and a refrigerant flowing inside the inner tube is interposed between the inner tube and the outer tube. A multi-tube condensation heat exchanger configured to be capable of exchanging heat with flowing hot and cold hot water, wherein the inner tube has a multi-leaf tube shape, and the inner tube is An elastic body is provided in the central portion of the multi-leaf tube to be formed, and the elastic body is blocked by the elastic body so that the refrigerant does not flow through the central portion, and the elastic body is configured to perform the heat exchange in which the refrigerant flows in a gas-liquid mixed state or a liquid state It is characterized in that it is provided in the latter half of the flow direction of the refrigerant in the vessel .

  According to the first aspect of the present invention, there is provided an inner pipe and an outer pipe containing the inner pipe therein, a refrigerant flowing inside the inner pipe, hot water and hot water flowing between the inner pipe and the outer pipe, It is a multi-tube type condensation heat exchanger that is configured so that heat can be exchanged between, and the inner tube is formed in a multi-leaf tube shape, and an elastic body is provided at the center of the multi-leaf tube that forms the inner tube, Since the elastic body blocks the refrigerant so that the refrigerant does not flow through the central portion, the refrigerant can be prevented from flowing through the central portion of the inner tube, heat exchange performance can be improved, and the amount of refrigerant charged can be reduced.

And since the said elastic body is provided in the latter half part of the distribution direction of the refrigerant | coolant of the said heat exchanger with which a refrigerant | coolant flows in a gas-liquid mixed state or a liquid state, a refrigerant | coolant distribute | circulates to the center part of a multileaf tube. The amount of the elastic body to be prevented can be saved, and the necessary amount of refrigerant can be efficiently reduced.

1 is an exploded perspective view of a triple tube heat exchanger, an upper heat insulating material, and a lower heat insulating material according to an embodiment of the present invention. It is sectional drawing of the triple tube | pipe type heat exchanger of FIG. It is sectional drawing of the triple tube | pipe type heat exchanger of FIG. It is a fragmentary perspective view of the double multileaf tube which forms an inner tube.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

The overall structure of the triple pipe heat exchanger 1 of the present invention will be described.
As shown in FIGS. 1 to 4, the triple tube heat exchanger 1 (which corresponds to a multiple tube condensation heat exchanger) includes an inner tube 2, a leak detection tube 3, and an outer tube 4. The pipe 2 has an inner fluid passage 5, and an outer fluid passage 6 between the leak detection pipe 3 and the outer pipe 4. Heat exchange is performed between the refrigerant flowing in the inner fluid passage 5 and hot water flowing in the outer fluid passage 6. Is configured to do.

As shown in FIG. 1, the triple-pipe heat exchanger 1 is configured in a rectangular spiral shape as a whole and includes a plurality of loop tubes 7 having a substantially rectangular shape in plan view. The plurality of loop tubes 7 are arranged in two layers in the vertical direction so that each layer has a plurality of turns (triple turns). The three loop tubes 7 arranged in each layer are configured to have a size that gradually increases from the inside toward the outside.
The triple-pipe heat exchanger 1 is covered with an upper heat insulating material 8 and a lower heat insulating material 9 which are divided into upper and lower parts obtained by foaming a resin such as expanded polypropylene and expanded polystyrene.

  At both ends of the triple-pipe heat exchanger 1, a branch part 10 into which hot water before heating is introduced and a low-temperature refrigerant is led out, and a branch from which heated hot water is led out and a high-temperature refrigerant is introduced. Part 11 is formed. A refrigerant passage 13a is connected to the inner tube 2 in the vicinity of the branch portion 11, a circulation pipe 4b is connected to the outer tube 4, and a refrigerant passage 13b is connected to the inner tube 2 in the vicinity of the branch portion 10. 4 is connected to a circulation pipe 4a. The triple-pipe heat exchanger 1 is disposed so as to have a horizontal posture as a whole, and is disposed such that the branching portion 11 is located above the branching portion 10.

Next, the internal structure of the triple-pipe heat exchanger 1 will be described with reference to FIGS.
The triple pipe heat exchanger 1 includes an inner pipe 2, a leak detection pipe 3, and an outer pipe 4, and the inner pipe 2, the leak detection pipe 3 and the outer pipe 4 have a circular cross section made of, for example, phosphorous deoxidized copper. It is manufactured using a material pipe of a predetermined length made of a copper pipe for water supply or an equivalent product thereof. The thickness of the tube wall of the material pipe is, for example, 0.6 to 1.0 mm, and the outer diameter of the triple pipe heat exchanger is, for example, 16 to 20 mm. However, these numerical values are illustrative and are not limited thereto.

  As shown in FIG. 2, the inner tube 2 is configured as a multi-leaf tube having a corrugated shape in which the tube wall repeats a crest 2 a and a trough 2 b in the circumferential direction. The leak detection tube 3 is a multi-leaf tube having substantially the same shape as the inner tube 2, and is fitted on the inner tube 2 and arranged in the vicinity of the outer peripheral surface of the inner tube 2. An inner tube 2 and a leak detection tube 3 are housed inside the outer tube 4.

  The inner fluid passage 5 inside the inner pipe 2 is formed of a fluid passage 5a surrounded by four valleys 2b and four fluid passages 5b inside the crests 2a. The outer fluid passage 6 therebetween is formed by four fluid passages 6a having a substantially triangular cross section.

  An elastic body 15 is provided in the fluid passage 5a at the center of the inner pipe 2, and the fluid passage 5a is closed by the elastic body 15 so that no refrigerant flows through the fluid passage 5a. The elastic body 15 is composed of a heat-resistant elastic body such as silicon rubber.

  Here, as will be described later, when the double multi-leaf tube 12 is manufactured, from the circular cross-sectional shape of the double tube in which the material tube of the inner tube 2 is inserted into the material tube of the leak detection tube 3, for example, a four-leaf shape is formed. By drawing into a cross-sectional shape, a fluid passage 5a at the center of the inner tube 2 is formed. For this reason, the cross-sectional shape of the fluid passage 5a is not necessarily finished in a constant shape, and the fluid passage 5a can be closed by adopting the elastic body 15.

  The multi-leaf tube forming the inner tube 2 has a straight portion 2c that connects the peak portion 2a and the valley portion 2b in the axial orthogonal cross section, and the multi-leaf tube forming the leak detection tube 3 is the axial orthogonal cross section. , The straight portion 3c that connects the peak portion 3a and the trough portion 3b, and the straight portion 2c of the inner tube 2 and the straight portion 3c of the leak detection tube 3 that opposes the straight portion 3c are in close contact with each other.

  The straight portions 2c and 3c are strip-like tube walls twisted in a spiral shape, and the belt-like tube walls 2c and 3c are in close contact with each other. And the heat exchange performance between the hot water flowing in the outer fluid passage 6 is enhanced. In addition, since the integrity of the inner tube 2 and the leak detection tube 3 is increased, it is advantageous in securing rigidity. The peak portion 2a and a pair of linear portions 2c connected to the peak portion 2a are formed in a fan shape with an opening angle of about 45 °, and the same applies to the leak detection tube 3.

  Most of the crest 2a of the inner tube 2 is in surface contact with the inner surface of the crest 3a of the leak detection tube 3, and most of the crest 3a of the leak detection tube 3 is in surface contact with the inner surface of the outer tube 4. It is closely attached to the shape. Therefore, the overall rigidity of the triple pipe heat exchanger 1 can be increased, and the heat exchange performance between the refrigerant flowing in the inner fluid passage 5 and the hot water flowing in the outer fluid passage 6 is also improved.

  FIG. 4 shows a double multi-leaf tube 12 composed of an inner tube 2 and a leak detection tube 3 inserted into the outer tube 4. When manufacturing the double multi-leaf tube 12, for example, a cylindrical elastic body 15 is inserted inside the material tube of the inner tube 2, and the material tube of the inner tube 2 is inserted into the material tube of the leak detection tube 3. This double tube is processed into a four-leaf shape, for example, so that a double multi-leaf tube 12 provided with an elastic body 15 at the center is manufactured. In a state where the double multi-leaf tube 12 is inserted into the material tube of the outer tube 4, at least the outer tube 4 is reduced in diameter to manufacture the triple tube heat exchanger 1. Note that both the double multi-leaf tube 12 and the outer tube 4 may be reduced in diameter.

  As shown in FIG. 4, the double multi-leaf tube 12 is configured in a spirally twisted shape with a predetermined lead angle. The predetermined lead angle is an angle that makes one rotation for every 300 to 500 mm in the axial direction, for example. Since the above twist is added, it becomes easy to wind the triple tube heat exchanger 1 when it is configured as a heat exchanger having a coil structure, and the triple tube heat exchanger A stirring action can be obtained with respect to the fluid flowing through the inside of the tank. However, the above twisting is not essential and may be omitted.

The elastic body 15 is provided in the latter half of the refrigerant flow direction of the triple pipe heat exchanger 1 in which the refrigerant flows in a gas-liquid mixed state or a liquid state.
Here, since the refrigerant flows into the inner fluid passage 5 from the refrigerant passage 13a side and flows out from the refrigerant passage 13b side, the refrigerant flows in the loop pipe 7 counterclockwise. On the other hand, since the hot water flows in the outer fluid passage 6 from the circulation pipe 4a side and flows out from the circulation pipe 4b side, the hot water flows in the loop pipe 7 in the counterclockwise direction of the refrigerant.

  As the refrigerant used in the triple pipe heat exchanger 1, propane gas is mainly used, and the refrigerant that has flowed into the inner fluid passage 5 from the refrigerant passage 13a side is in a gaseous state, but the outer fluid passage 6 When heat is exchanged with the hot water flowing in the counterflow in the interior and the refrigerant flows out from the refrigerant passage 13b side, it is in a liquid state.

  Accordingly, the latter half of the refrigerant flow direction refers to a plurality of loop pipes 7 arranged in a lower layer among a plurality of loop pipes 7 arranged in two layers above and below, Only the elastic body 15 is provided. However, the elastic body 15 may be provided not only in the latter half portion of the triple pipe heat exchanger 1 but also in the first half portion.

Next, the operation and effect of the triple pipe heat exchanger 1 will be described.
In this triple tube heat exchanger 1, the inner tube 2 and the leak detection tube 3 are formed in a multi-leaf tube shape, and an elastic body 15 is provided in the inner fluid passage 5a which is the center of the double multi-leaf tube 12, Since the elastic body 15 blocks the refrigerant so that the refrigerant does not flow through the inner fluid passage 5a, the refrigerant can be prevented from flowing through the inner fluid passage 5a, heat exchange performance can be improved, and the amount of refrigerant charged can be reduced.

  The elastic body 15 is provided in the second half of the refrigerant flow direction of the triple tube heat exchanger 1 in which the refrigerant flows in a gas-liquid mixed state or in a liquid state. It is possible to reduce the amount of the elastic body 15 used to prevent the refrigerant from circulating and efficiently reduce the necessary amount of refrigerant.

  Note that in the first half of the refrigerant flow direction of the triple-pipe heat exchanger 1, the refrigerant is in a gas state, and the amount of refrigerant present in the central portion of the multi-leaf tube forming the inner tube is small. Therefore, even if an elastic body is provided there, the effect of reducing the charging amount of the refrigerant is poor, and therefore the elastic body 15 is provided in the latter half portion of the triple-pipe heat exchanger 1 in the refrigerant flow direction.

Next, an example in which the above embodiment is partially changed will be described.
1) The number of peak portions 2a, 3a and the number of valley portions 2b, 3b in the double multi-leaf tube 12 including the inner tube 2 and the leakage detection tube 3 are not limited to four, and may be three or five or more.

  2) The metal material of the material tube of the inner tube 2, the leak detection tube 3 and the outer tube 4 is not limited to phosphorous deoxidized copper, but may be other various copper materials, and may be a metal other than copper (for example, aluminum or The alloy, brass, magnesium alloy, titanium, etc.) may be used. The inner tube 2, the leak detection tube 3, and the outer tube 4 are not necessarily manufactured from a material tube of the same kind of metal material, but may be manufactured from a material tube of a different kind of metal material. Moreover, the thickness of the tube wall of the inner tube 2 and the thickness of the tube wall of the leak detection tube 3 may be the same or different.

3) Although the example in which the elastic body 15 is provided in the triple pipe heat exchanger 1 has been described as an example, an elastic body is provided in the double pipe heat exchanger composed only of the inner pipe 2 and the outer pipe 4. It is also possible to configure.
4) The material of the elastic body is not limited to a cylindrical body, but may be a polygonal column. Moreover, you may employ | adopt a synthetic resin foam as a material of an elastic body.
5) In addition, those skilled in the art can implement the present invention in a form in which various modifications are added without departing from the spirit of the present invention.

1 Triple tube heat exchanger 2 Inner tube 4 Outer tube 12 Double multi-leaf tube 15 Elastic body

Claims (1)

An inner pipe and an outer pipe that accommodates the inner pipe are provided so that heat can be exchanged between the refrigerant flowing inside the inner pipe and hot water and hot water flowing between the inner pipe and the outer pipe. In the multi-tube condensation heat exchanger, the inner tube is formed in a multi-leaf tube shape,
An elastic body is provided at the center of the multi-leaf tube forming the inner tube, and the elastic body is closed so that no refrigerant flows through the center .
The multi-tube condensing heat exchanger is characterized in that the elastic body is provided in a second half portion in a refrigerant flow direction of the heat exchanger in which the refrigerant flows in a gas-liquid mixed state or a liquid state .