JP2647098B2 - Shell tube heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a shell tube type heat exchanger.

(Prior art) As a conventional two-set flow type shell tube type heat exchanger,
For example, there is a shell-tube type evaporator that heats and evaporates an object to be evaporated such as fluon in a tube axis direction of a heat transfer tube with a heat source fluid, and is widely used in a chemical industry, a refrigerator, a heat pump, and the like. In particular, in recent years, as the use of non-azeotropic mixed media has entered the practical stage as a means to dramatically improve the performance of geothermal water-based Rankine cycle power plants and heat pumps, the characteristics of non-azeotropic mixed media have been Shell-tube evaporators of the two-phase flow type that can be fully used have been recognized again. In such a shell tube type evaporator, the flow path of the fluid to be evaporated is inside the tube (inside the heat transfer tube).
Alternatively, either the shell side (outside the heat transfer tube) can be selected, but from the viewpoint of improving heat transfer performance and reducing pressure loss, the evaporation is divided into at least first and second evaporators, and the first and second evaporators are divided. For example, Japanese Unexamined Patent Publication No.
No. 57-122263 and JP-A-61-138063.

By the way, if such a shell tube type evaporator is constructed based on the prior art, for example, it becomes as shown in FIG. The first evaporator 101 includes a first shell 103 and a first heat transfer tube group 105.
And the second evaporator 107 includes a second shell 109 and a second shell 109.
And a heat transfer tube group 111.

The fluid A to be evaporated flows in from the lower inlet 113 of the first shell 103 and flows out from the upper outlet 115. The evaporating fluid A that has flowed out flows from the upper inlet 117 of the second shell 109 to the second
Of the heat transfer tube group 111, and flows out of the lower outlet 119.

On the other hand, the heat source fluid B is the second
From the lower inlet 121 of the shell 109 to the upper outlet 12
Spill out of 3. The discharged heat source fluid B is supplied to the first shell 103
And flows out of the lower outlet 127 through the first heat transfer tube group 105.

In such a flow, the inlet 1 of the first shell 103
In the vicinity of 13, a part of the fluid A to be evaporated adheres to the outer wall of the first heat transfer tube group 105, and a high heat exchange efficiency is obtained with a thin liquid film. However, the fluid A to be evaporated which adheres to the outer wall of the first heat transfer tube group 105 decreases toward the upper part of the first shell 103 and adheres to the inner wall of the first shell 103, and the first shell 103
Gas and the like in the inner flow path act as a heat insulating layer, and the heat exchange efficiency is rapidly reduced.

On the other hand, the fluid A to be evaporated is supplied to the upper inlet 1 of the second shell 109.
The flow is reversed from 17 and flows to the second heat transfer tube group 111. For this reason, the fluid A to be evaporated adheres to the inner wall of the second heat transfer tube group 111, so that the heat exchange efficiency is increased, and a decrease in the heat exchange efficiency as a whole can be avoided.

If a non-azeotropic mixed medium is used for the fluid A to be evaporated, the temperature of the fluid A to be evaporated is also reduced by the heat source fluid in combination with the fact that the fluid A to be evaporated and the heat source fluid B are in countercurrent. The difference from the temperature of the fluid B can be reduced, and the energy loss can be suppressed.

However, the configuration according to the above-mentioned prior art requires at least two heat exchangers, and thus cannot be made compact. Therefore, the use of the split-tube reversal-type shell-tube heat exchanger that can excel in heat transfer performance and reduce energy loss is limited, and its improvement has been desired.

(Problems to be Solved by the Invention) Such a shell tube type heat exchanger of the split flow channel reversal type is excellent in heat transfer performance and can sufficiently exhibit the characteristics of the non-azeotropic mixed medium. However, the device could not be made more compact.

Accordingly, it is an object of the present invention to provide a shell-tube heat exchanger that is excellent in heat transfer performance, reduces energy loss, and can be made compact.

[Structure of the Invention] (Means for Solving the Problems) In view of the above-described conventional problems, the present invention provides a first shell and a first transmission housed inside the first shell. A heat pipe group, a second shell forming an annular flow path outside the first shell, and a second heat transfer pipe group housed in the annular flow path, the first shell being provided at one end. A first flow path reversing header for communicating the inside with the second heat transfer tube group; and a second flow path reversing header for communicating the annular flow path with the flow path in the first heat transfer tube group. At the other end, a first inlet / outlet for flowing a fluid into a first flow path formed by the first shell and the second heat transfer tube group, and the first heat transfer tube group and the annular flow passage And a second inlet / outlet for flowing a fluid in a direction opposite to the flow of the fluid in the first flow path.

(Operation) In the above configuration, the flow direction of the fluid flowing from the first port into the first flow path and the direction of the fluid flowing from the second port into the second flow path are always opposite. Heat exchange between the fluid in the first flow path and the fluid in the second flow path is also performed via the first shell itself.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a shell-tube heat exchanger 1 according to one embodiment of the present invention.

First, the first shell 3 has a cylindrical shape having a predetermined diameter,
A first flow path reversing header 5 is provided integrally at the upper end. Inside the first shell 3, first heat transfer tube groups 7 are accommodated at predetermined intervals in the axial direction, and the first heat transfer tube groups 7 are accommodated.
Are supported through the upper wall 5a of the first flow path reversing header 5. A second shell 9 is arranged concentrically around the outer periphery of the first shell 3, and an annular flow path 11 is formed by the second shell 9 and the first shell 3. A second heat transfer tube group 13 is accommodated in the axial direction of the annular flow passage 11, and the second heat transfer tube group 13 is arranged at a predetermined interval in a circumferential direction in the annular flow passage 11, and an upper end portion is formed of the second heat transfer tube group 13. The first flow path reversing header 5 is supported through the lower wall 5b. Accordingly, the inside of the first shell 3 is inverted by the first passage reversing header 5 and communicates with the inside passage of the second heat transfer tube group 13.

At the upper end of the second shell 9, a second flow path reversing header 15 is provided integrally so as to cover the first flow path reversing header 5. Accordingly, the flow path of the annular flow path 11 is reversed by the second flow path reversing header 15 and communicates with the internal flow path of the first heat transfer tube group 7.

On the other hand, the other end of the heat exchanger 1 has the inside of the first shell 3 and the second
Of the fluid flowing through the flow path constituted by the heat transfer tube group 13
Doorway is provided. This first entrance is the inlet
17 and an outlet 19, wherein the inlet 17 is the first
The shell 3 is provided in communication with the inside by the lower side surface. The outlet 19 is provided in communication with a lower portion of the second heat transfer tube group 13.

The heat exchanger 1 includes the first heat transfer tube group 7 and an annular flow path.
A second port for flowing a fluid through the flow path defined by 11 is provided. The second entrance is the inlet 21 and the outlet
The inflow port 21 is provided so as to communicate with a lower portion of the annular flow path 11. The outlet 23 communicates with the first heat transfer tube group 7 and is provided on the lower surface of the second shell 9.

 Next, the operation of the above embodiment will be described.

First, the working fluid A uses, for example, a non-azeotropic mixed medium, and flows into the first shell 3 from the inflow port 17. The flowing working fluid A partially adheres to the outer wall of the first heat transfer tube group 7 near the inflow port 17 by a thin liquid film, and flows into the upper part in the figure while acting with high heat exchange efficiency. The liquid film of the working fluid A attached to the outer wall of the first heat transfer tube group 7 decreases toward the upper part.

On the other hand, the flow path of the working fluid A is reversed by the first flow path reversing header 5 provided at the upper end of the first shell 3. The inverted working fluid A flows into the in-pipe flow path from the upper part of the second heat transfer pipe group 13 and flows to the lower part in the figure. For this reason, the working fluid A adheres to the inner wall of the second heat transfer tube group 13 and flows out from the outlet 19 while maintaining a high heat exchange efficiency.

On the other hand, the heat source fluid B flows into the annular flow path 11 from the inflow port 21 and exchanges heat with the above-described working fluid A while flowing into the upper part in the drawing. The flow path of the heat source fluid B flowing into the upper part is reversed by the second flow path reversing header 15 provided integrally with the upper end of the second shell 9. The inverted heat source fluid B is the first
Flows from the upper part of the heat transfer tube group 7 into the flow path in the pipe, flows to the lower part in the figure while performing heat exchange, and flows out from the outlet 23.

Therefore, it is possible to prevent a decrease in the heat exchange efficiency as a whole, and to provide the second shell 9 around the outer periphery of the first shell 3.
Can be concentrically arranged and singulated.

Further, since the non-azeotropic mixed medium is used as the working medium A and the flow directions of the working fluid A and the heat source fluid B are caused to flow countercurrently, the heat source fluid B is upstream of the working fluid A by heat exchange. The temperature decreases toward (inlet 17). Further, the working fluid A, which is a non-azeotropic mixed medium, rises in the flow direction even during evaporation due to the difference in boiling point of the mixed single component medium. Therefore, the temperature difference between the working fluid A and the heat source fluid B during heat exchange in the shell-tube heat exchanger 1 can be reduced, and irreversible energy loss can be suppressed.

The present invention is not limited to the above embodiment. For example, in the configuration of the present embodiment, the flow paths of the working fluid A and the heat source fluid B may be reversed. Further, the outlet and the inlet provided respectively may be reversed. The heat exchanger 1 may be installed horizontally or inclined.
A single component medium can also be used as the working medium.
Further, it is a matter of course that the respective passages through which the fluid flows can be subjected to a process of accelerating boiling and a process having a liquid film holding function. The heat exchanger 1 can also be configured as a condenser.

[Effects of the Invention] As can be understood from the above description of the embodiments, in the present invention, the flow rate of the fluid in the first flow path formed by the first shell and the second heat transfer tube group is determined. Flow direction and first
Since the flow direction of the fluid in the second flow path constituted by the heat transfer tube group and the annular flow path is always the opposite direction throughout, the fluid in the first flow path and the second flow path When heat exchange is performed between the two fluids, the temperature difference between the two fluids can be reduced, and energy loss can be suppressed.

Further, according to the present invention, the first heat transfer tube group housed in the first shell is connected to the annular flow passage formed between the first shell and the second shell. Since the second heat transfer tube group accommodated in the annular flow path is connected to the inside of the first shell, the first heat transfer tube group is surrounded by the first shell, and the first shell is surrounded by the first shell. And the second shell surrounding the second heat transfer tube group is surrounded by the second shell. Fluids flowing inside and outside the first shell are completely different fluids, and heat exchange is performed between the different fluids. At this time, the first shell itself is also used as a heat transfer body, so that the overall configuration can be made compact.

That is, according to the present invention, the overall structure can be made compact while maintaining the advantages of the shell-tube heat exchanger of the split channel reverse type.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a shell tube type heat exchanger according to the present invention, and FIG. 2 is a sectional view showing a shell tube type heat exchanger according to the prior art. DESCRIPTION OF SYMBOLS 1 ... Shell tube type heat exchanger 3 ... 1st shell 5 ... 1st flow path reversal header 7 ... 1st heat transfer tube group, 9 ... 2nd shell 11 ... Annular flow path, 13 Second heat transfer tube group 15 Second flow path reversing header 17,19 First entrance 21,23 Second entrance

Claims (1)

(57) [Claims] 1. A first shell, a first heat transfer tube group housed inside the first shell, a second shell forming an annular flow path outside the first shell, A second heat transfer tube group housed in the annular flow path, and a first heat transfer tube communicating at one end with the inside of the first shell and the second heat transfer tube group.
And a second flow path reversal header for communicating the annular flow path with the flow path in the first heat transfer tube group. A first inlet / outlet for flowing a fluid through a first flow path formed by the heat transfer tube group;
A second heat transfer tube group and an annular flow path,
A flow passage having a second port through which a fluid flows in a direction opposite to a flow direction of the fluid in the first flow passage.