JP2007003014A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger having a smaller size and superior heat transfer performance. <P>SOLUTION: The heat exchanger comprises a flow path 1 in which first fluid flows and which is held between plates, and a flow path 2 in which second fluid flows, the flow path 1 meandering. In the flow path 1 held between the plates in which the first fluid distributes, a pipe is arranged in which the second fluid distributes. The pipe in the flow path 2 in which the second fluid flows is a leakage detecting pipe. The used leakage detecting pipe has a knurl or a fin additionally provided on the outer face. The pipe in which the second fluid distributes is arranged outside the plates in which the first fluid distributes, and irregular patterns exist inside the plates along the shape of the pipe. The fluid flowing in the flow path 2 is carbon dioxide refrigerant. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger for exchanging heat between two fluids, a high temperature fluid and a low temperature fluid.

Conventionally, a hot water heater generally uses a method in which combustible gas is burned and water is directly heated and supplied. However, due to recent environmental problems, high efficiency water heaters are being studied. And a heat pump system making hot water refrigerant heat pump is cold water heat exchanger it creates a high-temperature refrigerant using such Freon or CO _2, a high temperature is heat-exchanged water hot exhaust gas and cold water discharged from such as a generator The cogeneration method to make Such a method requires a compact heat exchanger that efficiently exchanges heat between the two fluids.

  Recently, natural refrigerants for global environmental conservation have been put into practical use, and the market for heat pump water heaters using carbon dioxide refrigerant is expanding. Accordingly, various studies have been conducted on heat exchangers between high-temperature carbon dioxide refrigerant and heated water used for hot water supply.

  There is an example of a heat exchanger in which a high-temperature carbon dioxide refrigerant is caused to flow in a narrow tube wound around a thick tube through which heated water flows (for example, Patent Document 1). There is an example of a heat exchanger in which a leak detection tube through which a high-temperature carbon dioxide refrigerant flows is arranged inside a thick tube through which heated water flows (for example, Patent Document 2). An example of a heat exchanger in which a circulating portion of heated water is sandwiched between two plates, a thin tube through which high-temperature carbon dioxide refrigerant circulates is wound around the plate, and a corrugated plate is inserted (For example, Patent Document 3). A heat exchanger having a leakage detection tube along the flow path is formed by sandwiching the water to be heated between two plates and providing a convex portion on the plate to meander the water to be heated. There is an example (for example, patent document 4).

JP 2002-228370 A JP 2004-360974 A JP 2003-314975 A JP 2005-24109 A

  However, the heat exchangers of Patent Literature 1 and Patent Literature 2 have a problem that the size is increased. This is because a coiled heat exchanger is formed by bending the tubular body, and as a result, when adjacent tubular bodies come into contact with each other, the heat transfer performance deteriorates, so that it is necessary to make a gap. Patent document 3 and patent document 4 cause the problem that heat transfer performance is inferior. This is because the plate-type heat exchanger is a basic form, and the flow path of the water to be heated formed by laminating the plates becomes linear.

  In view of such problems, the present invention has been made, and provides a heat exchanger that is small in size and excellent in heat transfer performance.

The present inventors have found that a heat exchanger that is small in size and excellent in heat transfer performance can be manufactured.
That is, the present invention
(1) A heat exchanger (1) in which a flow path 1 through which a first fluid flows is sandwiched between plates, has a flow path 2 through which a second fluid flows, and the flow path 1 meanders. 2) The heat exchanger according to (1), wherein a pipe through which the second fluid flows is disposed in the flow path 1 sandwiched between the plates through which the first fluid flows. (2) The heat exchanger according to (1) to (2), wherein the pipe of the flow path 2 through which the fluid 2 flows is used. (4) Use a leak detection pipe in which knurls or fins are added to the outer surface of the leak detection pipe. The heat exchanger according to any one of (1) to (3) (5) A tube through which the second fluid flows is disposed outside the plate through which the first fluid flows, and follows the shape of the tube The fluid flowing in the heat exchanger (6) flow path 2 according to (1) is characterized by having irregularities on the inside of the plate. Characterized in that a refrigerant (1) to the heat exchanger according to any one of (5),
Is to provide.

  In the heat exchanger of the present invention, the flow path A through which the first fluid flows is sandwiched between the plates 2, the flow path B through which the second fluid flows is provided, and the flow path A meanders. Excellent heat transfer performance.

A heat exchanger 1 according to the present invention will be described with reference to FIGS. 1 to 6.
FIG. 1A is a plan view, FIG. 1B is a side view, and FIG. 1C is an XY cross-sectional view of an embodiment showing the arrangement of tubes of a heat exchanger 1 according to the present invention. A path through which heated water (heated water) flows is formed by bonding the plates 2 together. And the refrigerant | coolant pipe | tube 3 through which a refrigerant | coolant distribute | circulates inside the plate 2 to which the to-be-heated water distribute | circulates is arranged to meander. In this way, in the cross section of FIG. 1 (c), the refrigerant pipe 3 can act like a baffle plate with respect to the flow of the water to be heated, and a turbulent flow effect can be given to the water to be heated. Improve heat transfer performance. The plate 2 may be placed horizontally or vertically.

  FIG. 3 shows an embodiment of the cross-sectional shape of the leak detection tube 4 according to the present invention. In the heat exchanger 1 of FIG. 1, since the refrigerant pipe 3 and the water to be heated are in direct contact, it is desirable to use the leak detection pipe 4 having the leak detection hole 5 in the refrigerant pipe 3.

  FIG. 4 shows an example of a cross-sectional shape of the knurled leak detecting tube 6 according to the present invention. It is more effective for the heat transfer performance to increase the outer surface area of the pipe by subjecting the outer face of the refrigerant pipe 3 that comes into contact with the water to be heated to an outer face process such as knurling or finning.

  2A is a plan view, FIG. 2B is a side view, and FIG. 2C is an XY cross-sectional view showing an arrangement of the tubes of the heat exchanger 1 according to the present invention. A path through which heated water (heated water) flows is formed by bonding the plates 2 together. And it arrange | positions so that the refrigerant | coolant pipe | tube 3 with which a refrigerant | coolant distribute | circulates in the outer surface of the plate 2 may bite. In this way, in the cross section of FIG. 2 (c), irregularities are formed on the plate 2 on the heated water side, so that a turbulent flow effect can be given to water and heat transfer performance can be improved. . The plate 2 may be placed horizontally or vertically.

  The plate 2 may be joined to the refrigerant tube 3 simply by biting, but may be joined by brazing material or solder. In addition, since the to-be-heated water used as drinking water does not contact the refrigerant pipe 3 directly, it is not necessary to use a leak detection pipe.

  In addition, it is difficult to attach a heat insulating material or the like with a conventional coil wound heat exchanger, but with the heat exchanger 1 of the present invention, a heat insulating process can be easily performed by simply winding a sheet-shaped heat insulating material. It can be carried out.

In addition, the refrigerant | coolant pipe | tube 3 consists of what has heat conductivity. A metal is excellent in thermal conductivity, and copper or a copper alloy is more preferable among them.
Next, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

  Examples 1-3 of this invention used the heat exchanger 1 of FIG. The plate 2 in FIG. 1 was made of a plate material made of phosphorous deoxidized copper and having a thickness of 5 mm. The size of the heated water flow path of the plate 2 is length A = 500 mm, width B = 200 mm, and thickness C = 15 mm. The refrigerant tube 3 was manufactured by arranging two pipes with an outer diameter D = 6.35 mm, a bending pitch P = 20 mm, and a deviation pitch of P1 = 10 mm and P2 = 6.35 mm. The effective heat transfer length of the refrigerant pipe 3 is 4.8 m / line × 2. In the present invention example 1, a smooth tube having an outer diameter D = 6.35 mm and a wall thickness t = 1.2 mm, and in the present invention example 2, a leak detection tube 4 having an outer diameter D = 6.35 mm and an inner diameter d = 3.5 mm. In Inventive Example 3, a knurled leak detecting tube 6 having a depth h = 0.5 mm, a twist angle θ = 40 degrees, and 13 grooves on the outer surface of the leak detecting tube 4 of Inventive Example 2 was used.

  Example 4 of the present invention used the heat exchanger 1 of FIG. The plate 2 of FIG. 2 was manufactured by a plate material made of a phosphorus deoxidizing cylinder and having a thickness of 5 mm. The size of the heated water flow path of the plate 2 is length A = 500 mm, width B = 200 mm, and thickness C = 15 mm. The refrigerant tube 3 having an outer diameter D = 6.35 mm and a wall thickness t = 1.2 mm was pressed from the outer surface of the plate 2 and then joined by brazing.

  As a comparison with the conventional material, a double tube heat exchanger was used. FIG. 5 is a cross-sectional view of one embodiment of a double tube heat exchanger. The outer tube 7 has an outer diameter D1 = 12.7 mm × thickness t1 = 0.6 mm, the inner tube 8 has an outer diameter D2 = 6.35 mm × thickness t2 = 1.2 mm, and the heat transfer measurement section length of the refrigerant tube 3 Two pieces having a length of 4.8 m were manufactured, and a fluid was allowed to flow in the direction of the flow paths W1 and W2 in parallel with the double-pipe heat exchanger.

  A heat transfer experiment was conducted on the heat exchanger. High-temperature water with an inlet temperature fixed at 60 ° C. is circulated through the two refrigerant pipes 3 at a total flow rate of 2 liters / minute, and the inlet temperature is fixed at 10 ° C. at a flow rate of 2 liters / minute on the heated water side. The low-temperature water thus circulated was counterflowed, and the exchange heat quantity of the heated water at that time was measured. The amount of exchange heat was evaluated by the ratio when the conventional example was set to 100. The measurement results are shown in Table 1. As shown in Table 1, it can be seen that the inventive examples have high heat transfer performance.

It is the top view of one Example which showed arrangement | positioning of the pipe | tube of the heat exchanger 1 which concerns on this invention, a side view, and XY sectional drawing. It is the top view of one Example which showed arrangement | positioning of the pipe | tube of the heat exchanger 1 which concerns on this invention, a side view, and XY sectional drawing. It is one Example of the cross-sectional shape of the leak detection pipe | tube 4 which concerns on this invention. It is one Example of the cross-sectional shape of the knurled leak detection pipe | tube 6 which concerns on this invention. It is an example of the conventional double pipe type heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Plate 3 Refrigerant tube 4 Leak detection tube 5 Leak detection hole 6 Knurling processing leak detection tube 7 Outer tube 8 Inner tube A Length B Width C Thickness P Bending pitch P1 Width interval P2 Height interval W Channel W1 channel W2 channel

Claims (6)

  A heat exchanger characterized in that a flow path 1 through which a first fluid flows is sandwiched between plates, has a flow path 2 through which a second fluid flows, and the flow path 1 meanders.   The heat exchanger according to claim 1, wherein a pipe through which the second fluid flows is disposed in the flow path 1 sandwiched between the plates through which the first fluid flows.   The heat exchanger according to claim 1 or 2, wherein the pipe of the flow path 2 through which the second fluid flows is a leak detection pipe.   The heat exchanger according to any one of claims 1 to 3, wherein a leak detection tube in which knurls or fins are added to an outer surface of the leak detection tube is used.   2. The heat exchanger according to claim 1, wherein a tube through which the second fluid flows is disposed outside the plate through which the first fluid flows, and has irregularities on the inside of the plate along the shape of the tube. .   The heat exchanger according to any one of claims 1 to 5, wherein the fluid flowing through the flow path 2 is a carbon dioxide refrigerant.

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