JPS5952195A - Heat exchanger - Google Patents

Abstract

PURPOSE:To provide a structure, in which both members are tightly joined with each other by utilizing thermal, dimensional change by a constitution wherein at least either one of heat conductive member to radiate or absorb heat and passage member to form a passage of medium to heat or to be heated is made of irreversible shape memory alloy. CONSTITUTION:The passage pipe 3, which penetrates flanged holes 2 of a large number of fins 1, is in a state to slightly contact with said flanged holes 2 in a finned tube type heat exchanger. The passage pipe 3 is made of irreversible shape memory alloy and its diameter is finished smaller than that of the flanged hole 2 at normal temperature. When heated under the state as mentioned above, the diameter of the passage pipe 3 increases, resulting in completely joining the passage pipe 3 to the flanged holes 2 of the fins 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat exchanger that transfers heat from a heating body to a heated body used in water heaters and air conditioners.

Conventional configuration and its problems In conventional heat exchangers, fins are often used to improve the heat transfer coefficient between the heating element and the heated element in order to increase the heat exchange efficiency. Means is taken to bring the heating element or the passage member through which the heating element or the heated element passes into close contact.

FIG. 1 is a sectional view showing a close contact means of a conventional fin tape type heat exchanger, in which a passage member 103 is inserted into a nail hole 102 of a large number of fins 101 arranged at equal intervals, and then, By forcibly inserting a tube expansion rod 104 having a spherical tip, the diameter of the passage portion 1O3 is expanded and brought into close contact with the nail hole 102 of the fin 1o1. In this method, stocks 5 pipe rods 10
There was a problem in that the insertion of 4 required a great deal of force and the production equipment became large-scale. Furthermore, since a plurality of passage members 103 are usually inserted into the fin 101, expanding each passage member is a labor-intensive task.

In addition to the method shown in Fig. 1, there is also a method of expanding the pipe by applying water pressure, but this requires production equipment such as a water pressure pump and a sealing device for pressurization, which is more than that shown in Fig. 1.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a method for easily achieving close contact, instead of means for ensuring close contact using a tube expansion rod or water pressure.

Structure of the Invention The present invention provides a heat exchanger having a heat conductive member that radiates or absorbs heat and a passage member that forms a passage for a heating body or a heated body. One side is made of an irreversible shape memory alloy, and by heating or cooling the heat conduction member and the passage member in contact with each other, the dimensions of the member made of the shape memory alloy change and the two become firmly attached. The idea is to do so.

Description of examples Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a fin-tube type heat exchanger in which passage pipes 3 passing through nail holes 2 of a large number of fins 1 are in light contact with each other. The passage pipe 3 is made of an irreversible shape memory alloy and has a small diameter at room temperature.

For example, by heating in the state shown in FIG. 2, the diameter of the passage pipe 3 increases as shown in FIG. 3, and it comes into complete contact with the nail hole 2 of the fin 1. If the heat exchanger is used for hot water supply or space heating, the passage pipe 3 is preferably made of a shape memory alloy whose diameter increases when heated. For example, for an instantaneous gas water heater, lead dipping is performed to improve the corrosion resistance of the fins, but if the material is selected in advance so that the pipe can be expanded at this temperature, a process to ensure special adhesion is necessary. There is no need to provide it, which is extremely advantageous in terms of production.

FIG. 4 is a sectional view showing another embodiment, which has a passage pipe 5 which has a substantially triangular cross section and is inscribed in a heat conduction pipe 4 in which each apex spirals in the length direction. ing. passage pipe 6
The dimensional change may occur so that the heat conduction tube 4 expands, or the dimensional change may occur such that the heat conduction tube 4 contracts. Of course, it is also possible to change the dimensions of both to make them tightly adhere to each other. For example, if this heat exchanger is used for hot water supply in which ethylene glycol or hapropylene glycol is passed through the passage pipe 5 to heat water outside the heat conduction tube 4, one of the passage pipe 5 and the heat conduction tube 4 can be heated. Even if the heat exchanger is damaged, the heat medium will not mix into the hot water supply, so it is used as a safe heat exchanger. Furthermore, when heat is exchanged by flowing the object to be heated through the spiral path 6 between the heat conduction tube 4 and the passage tube 5, the outer periphery of the heat conduction tube 4 is heated through the contact point 7 of both tubes, so there is only a double layer. High heat exchange efficiency can be ensured compared to pipes.

In addition to these embodiments, evaporators and condensers of refrigeration circuits,
Furthermore, it can be widely applied to solar heat collectors having fins.

Effects of the Invention As described above, according to the heat exchanger of the present invention, at least one of the heat conductive member that radiates or absorbs heat and the passage member that forms the passage for the heating body or the heated body has irreversible shape memory. Since it is made of an alloy and has a structure that uses thermal dimensional changes to firmly adhere the two, sufficient adhesion can be ensured without using mechanical pipe expansion equipment. In this tube expansion, there is no loosening due to springback that cannot be avoided when expanding the tube by external force, so the adhesion 5 is extremely good, and it is also possible to improve the heat exchange efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional tube expansion state, and FIG. FIG. 3 is a cross-sectional view of a fin-chip heat exchanger showing an embodiment of the present invention, and FIG. 4 is a cross-sectional view of a spiral double heat exchanger as another embodiment. 1.4...Heat conduction member, fin/heat conduction tube, 3
゜5... Passage member 2 passage pipe. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 4111J t74) 415-

Claims (1)

[Claims] It has a heat conductive member that radiates or absorbs heat, and a passage member that forms a passage for the heating body or the heated body, and at least one of the heat conduction member and the passage member is made of an irreversible shape memory alloy. A heat exchanger that brings the two into close contact.