JPS61285389A - Heat exchanger - Google Patents

Abstract

PURPOSE:To obtain the heat exchanger, prominent in heat exchanging performance, by a method wherein refrigerant is made to flow between inner and outer tubes while heat source fluid is made to flow through a heat exchanging chamber between the bundle of tubes, consisting of the inner and outer tubes, and the outer shell of the heat exchanger. CONSTITUTION:In the heat exchanger for low temperature difference electric power generating plate or the like, the refrigerant 8, such as Flon or the like, flows into a refrigerant inlet chamber 6 through a refrigerant inlet port 9, passes through a space between the inner tube 2 and the outer tube 5 of a double tube A while being evaporated and flows out of an outlet port 10 through a refrigerant outlet chamber 7. On the other hand, the heat source fluid 11 flows directly into the het exchanging chamber 14 between the outer shell 13 of main body 1 of the heat exchanger and the bundle of tubes consisting of the outer tubes 5 from an inlet port 12, flows to a direction reverse to the flow of refrigerant 8 and flows out of an outlet port 15. Another heat source fluid 11 flows from the inlet port 16 into a heat source fluid inlet chamber 3, flows through the inner tube 2 into a direction reverse to the flow of refrigerant 8 and flows out of the outlet port 17 through an outlet chamber 4. Thus, the improvement of heat exchanging performance may be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a heat exchanger used in a low temperature difference power generation plant such as geothermal binary cycle power generation, or a heat pump or refrigerator.

[Technical background of the invention and its problems]

An example of a refrigeration system using this type of heat exchanger will be explained with reference to FIG. The refrigeration system includes a compressor 22. Condenser 23. Pressure reducing device (e.g. capillary tube) 24. Evaporator 25. are connected by a pipe P to form a closed loop T-, and a refrigerant 8 such as fluorocarbon is sealed in the loop. Its operation is such that the refrigerant 8 is first compressed by the vapor total compressor 22, and the U-condenser 23 emits heat to a high temperature source to condense it. Next, the vapor of the condensed refrigerant 8 is subjected to isenthalpic expansion in the decompression device 24, and then is converted into vapor by removing heat from the low temperature source in the evaporator 25, which is then returned to the compressor 22.

A conventional evaporator 25 (or condenser 23) used in such a refrigeration system is shown in FIG.
(or the condenser 23), the heat source fluid 11 is transferred to the evaporator 25
Besides, the refrigerant 8 flows between the shell 13 and the tube bundle consisting of the heat transfer tubes 26, and the refrigerant 8 flows inside the heat transfer tubes 26 while evaporating (or condensing).

The flow pattern of the refrigerant 8 flowing through the heat exchanger tubes 26 changes as evaporation (or condensation) progresses, but in most areas, the surface liquid film 18 runs along the inner wall of the heat exchanger tubes 26, as shown in FIG. Also, the steam 27 forms an annular flow flowing through the center.

[Object of the Invention] The present invention takes the above-mentioned drawbacks into consideration and improves the heat exchange performance. a tube bundle consisting of an outer tube including at least one inner tube parallel to the longitudinal direction of the exchanger and spaced apart from each other; a heat source fluid inlet chamber communicating with one end of the inner tube; a heat source fluid outlet chamber communicating with the other end; a refrigerant inlet chamber communicating with the one end of the outer tube; and a refrigerant volume chamber communicating with the other end of the outer tube; flows between the inner tube and the outer tube, and the heat source fluid flows through a heat exchange chamber between the inner tube and the outer shell of the heat exchanger and a tube bundle consisting of the outer tube. It is.

〔Effect of the invention〕

According to the present invention, a heat exchanger with good heat exchange performance can be obtained.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same numbers are used for the same parts as in the conventional example.

Figure 1 shows a first embodiment of the present invention.
The heat exchanger 1 in this embodiment consists of a tube bundle consisting of four double tubes, and a heat source fluid inlet chamber 3, which communicates with the inner tube 2 of the double tube A. and a heat source fluid outlet chamber 4 which communicates with the inner tube 2 of the double front. and a refrigerant inlet chamber 6 communicating with the outer pipe 5 of the double pipe A. This is an evaporator consisting of a refrigerant outlet chamber 7 communicating with the outer pipe 5 of the double pipe A.

A refrigerant 8 such as fluorocarbon flows into the refrigerant inlet chamber 61 from the refrigerant inlet 9, flows through the cabinet E between the inner pipe 2 and the outer pipe 5 while evaporating, passes through the refrigerant outlet chamber 7t, and reaches the refrigerant outlet. It flows out from 10. The heat source fluid 11 directly flows from the heat source fluid population 12 into the heat exchange chamber 14 between the outer shell 13 of the heat exchanger 1 main body and the tube bundle consisting of the outer tube 5, and flows in the opposite direction to the flow of the refrigerant 8.
It flows out from the heat source fluid outlet 15. Separately from this, the heat source fluid 11 is passed from the heat source fluid inlet 16 to the heat source fluid inlet chamber 3.
, flows in the inner tube 2 in the opposite direction to the flow of the refrigerant 8 , passes through the heat source fluid outlet chamber 4 , and flows out from the heat source fluid outlet 17 .

Figure 2 shows the inner tube 2 of double tube A in the evaporator of this embodiment.
This figure shows one flow pattern of the refrigerant 8 flowing between the outer tube 5 and the outer tube 5 while evaporating H. The flow pattern of the refrigerant 8 changes as evaporation progresses.

In most areas, there is a circular flow as shown in the figure, and the liquid lI
! 18 is the outer surface S.1 of the inner tube 2 and the inner surface S.1 of the outer tube 5.
It flows along 2nd and 9th.

In the evaporator of this embodiment, even if the cross-sectional area of the refrigerant flow path is the same, the wetted length of the flow path is longer than that of the conventional evaporator 25 (see FIG. 9) in which the refrigerant 8 flows inside the tube. Therefore, the liquid flowing along the heat transfer surface [18 is not thin, the refrigerant 81111
The heat transfer coefficient of is increased, and the heat transfer performance of the heat exchanger 1 is improved.

Further, since the tube walls of the inner tube 2 and the outer tube 5 both stop at the heat transfer surface, the heat transfer area is increased compared to the conventional heat exchanger 25 even if the cross-sectional area of the refrigerant flow path is the same. Therefore.

Heat transfer performance is improved even with flow modes other than the annular flow shown in FIG.

[Other embodiments of the invention]

Next, other implementation sequences will be explained.

FIG. 3 shows a second embodiment of the invention. The present example is shown in FIGS. 1 and 2.

With such a structure, the heat source fluid population in the first embodiment can be reduced to 12. Since the heat source fluid outlet 15 is not required, the structure of the heat exchanger body, piping, etc. becomes extremely simple, leading to cost reduction.

Next, a third real example will be explained.

#! Figure 4 shows a third embodiment of the present invention.

FIG. 5 shows a cross section A-A' in FIG. 4.

The structure of this example is almost the same as the above-mentioned example, but
As shown in FIG. 5, the inside of the outer tube 5 includes a plurality of inner tubes 2 (seven in this embodiment) spaced apart from each other, and the refrigerant 8 such as fluorocarbon is Flow occurs between the tube bundle consisting of the inner tube 2 and the outer tube 5 with a metal phase change.

The heat source fluid 11 flows in a direction opposite to the flow of the refrigerant through the heat exchange chamber 14 between the tube bundle consisting of the inner tube 2 and the outer tube 5 and the outer shell 13 of the heat exchanger 1 body.

In this embodiment as well, the first. Heat transfer performance is improved for the same reason as in the second embodiment described above.

A fourth embodiment of the present invention is shown in FIGS. 6 and 7.

This embodiment is an evaporator that uses a non-azeotropic mixed medium 20 as the refrigerant, and its structure is almost the same as the first embodiment shown in Fig. 1, except for the double pipe structure. The outer surface of the tube 5 is provided with fins 21 which are elongated in the axial direction as shown in FIG.

It has been attracting particular attention in recent years because of the possibility that it may occur.

In order to make effective use of the characteristics of the non-azeotropic mixed medium, it is necessary to realize the opposing R1 of the heat source fluid and the non-azeotropic mixed medium in the evaporator or condenser.

In this embodiment, since the axial fins 21 are provided on the outer surface of the outer tube 5, the heat source fluid 11 flows into the heat exchange chamber between the tube bundle consisting of the outer tube 5 and the outer tube 13 of the heat exchanger 1 body. 14
It flows parallel to the axial direction of the T-double pipe. Therefore, almost complete counterflow between the heat source fluid 11 and the non-azeotropic mixed medium 20 can be realized. Therefore, the characteristic t of the non-azeotropic mixed medium 20
-Can be used effectively. Furthermore, since the heat transfer area is increased by the fins 21, heat transfer performance is also improved.

[Brief explanation of drawings]

Fig. 10 is a block diagram showing the first embodiment of the present invention, Figure 4 is a block diagram showing the third embodiment of the present invention, and the fifth factor is the fourth embodiment. A sectional view showing the AA' cross section in the figure, FIG. 6 is a configuration diagram showing the f-th beak treatment of the present invention, and FIG.
The figure is a perspective view showing the state of the outer tube in the fourth actual tIAn, FIG. 8 is a schematic system diagram of the refrigeration system, FIG. 9 is a configuration diagram showing a conventional evaporator (or condenser), and FIG. The figure is a cross-sectional view showing the state of refrigerant flowing in heat transfer tubes in a conventional evaporator (or condenser). 1... Heat exchanger, 2... Inner pipe, 3 Heatable source fluid inlet chamber. 4...Heat source fluid outlet chamber% 5...Outside! , 6... Refrigerant inlet chamber. 7... Refrigerant outlet chamber, 8... Refrigerant, 11... Heat source fluid, 14... Heat exchange chamber, 19... Communication pipe, 21...
·fin. Representative Patent Attorney Kensuke Chika (1 idiot) No. 4
Figure number 5! ii! l Figure 6

Claims (3)

[Claims] (1) In a heat exchanger that performs heat exchange between a first fluid that undergoes a phase change and a second fluid that serves as a heat source through a heat transfer wall, at least one fluid that is parallel to the longitudinal direction of the heat exchanger and spaced from each other A tube bundle consisting of an outer tube containing one or more inner tubes, a second fluid inlet chamber communicating with one end of the inner tube, and a second fluid inlet chamber communicating with the other end of the inner tube. an outlet chamber, a first fluid inlet chamber communicating with one end of the outer tube, and a first fluid outlet chamber communicating with the other end of the outer tube;
The first fluid flows between the inner tube and the outer tube, and the second fluid flows between the inner tube and the outer tube and the heat exchanger. A heat exchanger characterized in that a heat exchange chamber between the outer shell and the outer shell is configured to allow fluid to flow through the heat exchange chamber. (2) A communication pipe that communicates the heat exchange chamber between the tube bundle made of the outer tube and the outer shell of the heat exchanger with the second fluid inlet chamber, and the heat exchange chamber and the second fluid outlet. 2. The heat exchanger according to claim 1, further comprising a communication pipe that communicates the chambers. (3) The heat according to any one of claims 1 and 2, characterized in that the outer surface of the outer tube is provided with fins or spiral fins parallel to the longitudinal direction of the outer tube. exchanger.