JPS6130067Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heat exchange device that recovers sensible heat from exhaust gas, heated wastewater, etc. from factories, etc. by evaporation and condensation of a working fluid, and in particular, the heat receiving part (evaporation part), heat radiation part ( The present invention relates to a liquid supply device for a heat receiving section in a separate heat exchange device in which a condensing section (condensing section) exists independently at a long distance.

As a device that performs heat exchange or heat propagation using a working fluid, there is a heat pipe device that evaporates and condenses the working fluid within the same pipe. A typical example of this device is a pipe or cylindrical container 3 with both ends sealed, as shown in Figure 1.
A hollow porous material 31 called a pipe is placed on the inner circumference of the pipe, and a working fluid is sealed in the pipe.
This phase transformation of the working fluid and its movement are used to exert the heat propagation function. For example, in the illustrated heat pipe device, one side A of the pipe 30
If B is the heat receiving part and the other side B is the heat radiating part, the working fluid in this part evaporates due to the external sensible heat added to the heat receiving part A, becomes steam, and flows through the pipe 30 to the heat radiating part B as shown by the arrow. The pressure differential moves through the interior 32 and condenses, releasing latent heat. At the same time, this condensed liquid (working liquid) flows through the wick 31 to the heat receiving part A as shown by the arrow.

Such conventional heat pipe devices have the following problems.

(b) There is a dryout limit. If a heat input above a certain level is applied to the heat pipe, the inner surface of the heat receiving part dries out and the working fluid no longer exists in liquid form, making it impossible to operate normally. (b) Since the pipe is completely sealed, it is impossible to eliminate any non-condensable gas such as hydrogen gas generated. (c) Evaporation and condensation take place in one pipe, so
There is a limit to the distance between the evaporation section and the condensation section, that is, the length of the heat pipe itself, and for exhaust heat recovery, the limit is usually about 6 to 10 m. If the length is longer than this, the heat load on the heat receiving section and the heat dissipating section will become uneven, and the amount of movement of the working fluid or steam flowing inside the pipe will increase, causing various problems in the structure or performance of the heat pipe.

In order to eliminate the above-mentioned drawbacks, Japanese Patent Application Laid-Open No. 55-6177
In the publication, the heat receiving part and the heat radiating part are connected by separate insulated pipes, and the steam of the working fluid flows from the heat receiving part to the heat radiating part through one pipe, and condensed liquid flows from the heat radiating part to the heat receiving part. A separate type heat pipe device has been proposed in which the working fluid flows through the other pipe, thereby circulating the working fluid between the heat receiving section and the heat dissipating section while undergoing phase transformation. This device has good reflux of steam and condensate, and can effectively function as a heat pipe even if the heat receiving part and the heat radiating part are placed a long distance apart.

The present invention further improves the above-mentioned separate type heat pipe device, and forms a good wetted wall of the working fluid on the inner wall of the evaporation tube of the heat receiving part, thereby improving the evaporation rate of the working fluid. The purpose of this invention is to provide a liquid supply device for parts of the world.

As a specific example of a separate type heat exchange device to which the present invention can be applied, the heat receiving section and the heat dissipating section are each divided into three chambers, and a plurality of communication pipes (evaporation pipes, condensation pipes) are provided in the middle section. The upper section of the heat receiving section is used as a steam chamber, and the steam is introduced into the upper section of the heat radiating section through separate piping (steam pipe, liquid supply pipe, liquid recovery pipe). It has a structure connected to the chamber and the liquid recovery chamber in the lower section. In the present invention, a member having a capillary action is arranged from the outer wall of the upper end of the evaporation tube to the inner wall thereof.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a diagram schematically showing the overall structure of a separate type heat exchanger to which the present invention is applied. 1 is a heat receiving part (evaporating part) of this heat exchange device, 2 is a heat radiating part (condensing part), and both are located in a separate place,
These are connected by piping to constitute one sealed system as a whole. The working fluid undergoes phase transformation and circulates within this system. FIG. 3 is a view from above of the inside of the steam chamber of the heat receiving section according to the present invention, and FIG. 4 is a side sectional view thereof. First, the outline of the separate type heat exchanger shown in FIG. 2 will be explained.

The heat receiving section 1 has two partition plates 10, 1 inside its housing.
1, the upper steam chamber 14, the lower working fluid residual chamber 16, and the intermediate heat receiving part heat exchange chamber 15.
The heat exchange chamber 15 is arranged in a passage 33 for an external heat source fluid. First, as shown in FIGS. 2, 3, and 4, an overflow plate 20 is attached to the partition plate 10 between the steam chamber 14 and the heat exchange chamber 15, and this overflow plate 20 and one side wall of the steam chamber A working fluid reservoir section 21 is formed between the two and the hydraulic fluid reservoir section 21, and the fluid supply pipe 7 is introduced into this section. At the upper part of the steam chamber 14, there is a discharge port 1 for steam flowing toward the heat radiating section 2, as described later.
4a is formed. In the heat exchange chamber 15, a plurality of evaporation tubes 8 having both ends open are installed between the steam chamber partition plate 10 and the working liquid residual chamber partition plate 11.
This allows the steam chamber 14 and the working fluid residual chamber 16 to communicate with each other. An outlet 16a is provided at the bottom of the hydraulic fluid residual chamber 16 to take out the hydraulic fluid that remains without being evaporated.
In some cases, a vapor outlet is also formed near the upper part of the side wall of the residual chamber.

As shown in FIG. 2, the heat radiating section 2 has a housing divided into three chambers by two partition plates 12 and 13, similar to the heat receiving section 1, and the upper part is a steam introduction chamber 17 for the working fluid. , a heated fluid passage 34 whose intermediate portion is external
A heat exchange chamber 18 is connected to the heat dissipation section, and the lower part is a condensation chamber 19 for the working fluid. A plurality of condensing pipes 9 are provided in the heat radiating section heat exchange chamber 18, and both ends of the condensing pipes pass through the upper and lower partition plates 12 and 13, respectively, and open into the steam introduction chamber 17 and the condensing liquid chamber 19. , whereby both chambers 17 and 19 communicate with each other. Furthermore, the condensate chamber 19 has a non-condensable gas discharge pipe 2.
2 is provided, and hydrogen gas in the system is discharged from this exhaust pipe.
Non-condensable gases such as air are excluded.

A predetermined working fluid, such as water, is introduced from the tank 4 into the piping system connecting the heat receiving section and the heat radiating section. The working fluid is supplied by the pump 3 from the fluid supply pipe 7 to the working fluid reservoir 21 of the steam chamber 14 of the heat receiving section 1, where the 1
After being accumulated for a while, the water flows from the upper end of the overflow plate 20 onto the partition plate 10 as a uniform static flow, and as described later, enters the evaporation pipe 8 and forms a wet wall on the inner wall of the pipe. Here, the term "wet wall" means a state in which the pipe is not filled with hydraulic fluid and the inner wall of the pipe is wet. With such a wetted wall formed, heat is exchanged with the external heat source fluid passing through the heat receiving section heat exchange chamber 15, and the water forming the wetted wall evaporates and becomes steam.
The steam passes through the steam pipe 5 from the discharge port 14a of No. 4 and enters the steam introduction chamber 17 from the steam introduction port 17a of the heat radiating section 2 due to the pressure difference. In the heat radiating section 2, this steam flows down evenly through all the condensing tubes 9 of the heat radiating section heat exchange chamber 18, and on the way, it exchanges heat with the external heated fluid, thereby condensing the steam and turning it into a liquid. becomes. This condensed working liquid passes through the condensing liquid pipe 6 from the outlet 19a at the bottom of the condensing liquid chamber 19, and is again supplied to the working liquid reservoir section of the steam chamber 14 of the heat receiving section 1 via the pump 3 and the liquid supply pipe 7. ,
Repeat this.

In this embodiment, as shown in FIGS. 2 and 4, the upper end of each evaporator tube 8 is connected to the vapor chamber partition plate 10.
A cylindrical wire mesh 35 protrudes upward from the
is inserted. FIG. 5 is a view of this cylindrical wire mesh viewed from above, and FIG. 6 is a longitudinal sectional view of the cylindrical wire mesh inserted into the evaporation tube 8. The wire mesh 35 is a normal thin mesh having a mesh size of 100 meshes or less, preferably about 50 meshes. There are multiple notches 3 on the top end.
6 is inserted in the longitudinal direction. As shown in FIG. 6, the cylindrical portion 35a of the wire mesh 35 is inserted into the evaporation tube 8 so as to be in contact with the inner wall of the evaporation tube 8, and the notched portion 35b at the top extends from the upper end of the evaporation tube 8 to the outer wall. It is turned back toward. Folded portion 35b
The length of is such that its end reaches the partition plate 10. Such fine thin wire mesh has capillary action,
Therefore, the working fluid 37 accumulated on the partition plate 10 from the overflow plate 20 passes through the wire mesh 35 and is immersed in the evaporation tube 8, forming a good wetted wall on the inner wall of the tube. The length of the cylindrical portion 35a of the wire mesh inserted into the evaporation tube may be the entire length of the tube 8 or an appropriate length halfway up the tube. In addition to the above-mentioned wire mesh, the member that brings about such a capillary action may be any type of fibrous material such as glass fiber or cloth, or a porous cylinder made of sintered metal or the like may be fixed to the upper end of each evaporation tube. Alternatively, the evaporator tube itself may be formed of sintered metal. In both cases, the working fluid on the partition plate 10 is brought into contact with the outside of the evaporation tube. In the case of fibrous material, it may be applied only to the end of the evaporation tube, but if it is applied to the entire inner wall of the evaporation tube, a more uniform and better wetted wall will be formed.
Evaporation rate can be improved. In addition, in the case of the above-mentioned cylindrical wire mesh, it can be easily inserted into and removed from the evaporation tube, and various meshes can be used to adjust the supply amount of working fluid according to the heat amount or flow rate of the external fluid to be heat exchanged. It has the convenience of being able to be replaced. The amount of working fluid supplied is adjusted by adjusting the flow rate of the liquid supply pipe 7 to such an extent that a wetted wall can be formed on all the inner walls of all the evaporation pipes. Evaporation tube 8
The liquid remaining without being evaporated is stored in the lower working liquid residual chamber 1.
It flows down to 6. The hydraulic fluid accumulated in the hydraulic fluid residual chamber 16 is supplied from the outlet 16a by the pump 3 through the return pipe 23 and the liquid supply pipe 7 to the hydraulic fluid reservoir section 21 of the steam chamber 14, and is again supplied to the hydraulic fluid reservoir section 21 of the steam chamber 14. The steam accumulated in the upper part of the chamber passes through the steam pipe 5' on the side of the residual chamber, and flows together with the steam from the steam pipe 5 to the heat radiation section 2. Of course, these pipes are insulated from the outside. The tank 4 is also used for replenishing hydraulic fluid.

The above embodiment is an example in which the working fluid is forced to circulate by the pump 3 when the heat receiving part 1 and the heat radiating part 2 are at approximately the same height position or the heat radiating part 2 is at a high position. By performing this type of forced circulation, replenishment and circulation of the working fluid becomes easy and smooth, it is easy to control heat exchange load fluctuations, and there are no restrictions on the installation form of the heat receiving section and heat dissipating section. has the advantage of smooth operation. However, in the present invention, depending on the mutual positional relationship between the heat receiving part and the heat radiating part, such forced circulation is not performed, and the working fluid from the liquid circulation chamber 19 of the heat radiating part is naturally circulated from the liquid condensing pipe 6. Heat dissipation section 14 through bypass pipe 24
It may also be possible to lead to It should be noted that the present invention is also applicable to the case where the heat dissipating section 2 is located at a lower position than the heat receiving section 1.

As described above, the present invention configures the heat receiving part and the heat radiating part separately and independently, and connects them with piping dedicated to steam and piping dedicated to condensate, and a plurality of transmission lines are provided to each of the heat receiving part and the heat radiating part. A heat exchange chamber consisting of heat tubes is formed, and the working fluid is evaporated and condensed in this part and circulated from the heat receiving part to the heat radiating part and from the heat radiating part to the heat receiving part through separate insulated piping. Even if the distance between the heat dissipation section and the heat dissipation section is large, the return of steam and condensate is good during actual waste heat recovery, and stable operation is achieved even in the face of fluctuations in heat load.

Next, the effects of the present invention will be explained based on a more specific example.

The evaporation pipe in the heat receiving part 1 and the condensing pipe in the heat radiation part 2 are configured with a pipe diameter of 7 mm and a length of 700 mm,
49 tubes were installed in each tube, the distance between the heat receiving part and the heat radiating part was set 100 meters apart, and the working fluid supplied to the evaporation tubes was water, which was used to recover waste heat from a small combustion furnace. When carrying out the operation, 100 mesh wire meshes were inserted into all the evaporator tubes so as to form a wet wall on the inner wall of the evaporator tubes, and the working fluid flow rate 6 supplied from the liquid supply tube 7 was adjusted.
/min by forced circulation using pump 3. Combustion furnace exhaust gas is 17Nm ³ / 240℃
When cold air at 20°C was passed through the heat radiation section 2 at a rate of 17Nm ³ /min., it was found that the ratio of the amount of evaporation to the amount of supplied liquid The rate was 80-100%, while the exhaust gas passing through the heat exchange chamber of the heat receiving section could drop to 140℃, and the cold air passing through the heat exchange chamber of the heat dissipation section could rise to 110℃. At this time, 0.1 of air was exhausted from the non-condensable gas exhaust pipe 22 of the heat radiating section, and the efficiency in heat exchange was not reduced. In addition, the wire mesh allows water to be distributed evenly to all the evaporator tubes, forming a good wetted wall on the inner wall of the evaporator tube, resulting in a high evaporation rate. and the heat dissipation part is 100
Heat recovery could be carried out smoothly and with high efficiency even at a distance of 500 m. Although water was used as the working fluid in the above embodiments, it is possible to use any suitable working fluid such as freon or methanol depending on the required temperature of the heated fluid obtained by heat exchange.
The heat receiving part of the heat exchange device according to the present invention can be used alone or in a separate heat pipe device to recover waste heat from industrial combustion furnaces such as boilers, hot blast furnaces, and heating furnaces, and sinter coolers, and for general heating. It is suitable for application to industrial equipment, etc.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a conventional heat pipe, Fig. 2 is a schematic diagram of a separate heat exchanger to which the present invention is applied, and Fig. 3 is a plan view of a heat receiving steam chamber according to an embodiment of the present invention. Figure 4 -
Figure 4 is a vertical cross-sectional view of the heat receiving part, Figure 5 is a view from above of the wire mesh applied to the present invention, and Figure 6 is a vertical cross-sectional view of the evaporation tube with the wire mesh inserted. It is. 1...Heat receiving section (evaporation section), 2...Heat radiation section (condensing section), 5...Steam pipe, 6...Liquid recovery pipe, 7...Liquid supply pipe, 8...Evaporation pipe, 9...Condensation tube, 10, 11,
12, 13... Partition plate, 14... Steam room, 15...
...Heat receiving part heat exchange chamber, 16...Working fluid residual chamber, 17
... Steam introduction room, 18 ... Heat radiation section heat exchange room, 19
...Recovery liquid chamber, 33...External heat source fluid passage, 34...
... External heated fluid passage, 35 ... Wire mesh, 36 ...
Depth of cut, 37...Hydraulic fluid.

Claims (1)

[Scope of utility model registration request] The heat receiving section is divided into an upper steam chamber, a lower working fluid residual chamber, and an intermediate heat exchange chamber communicating with an external heat source fluid passage, and a plurality of evaporation tubes are disposed in the heat exchange chamber. In the separate type heat exchange device, the ends of the evaporator are opened to the steam chamber and the working fluid residual chamber, respectively, and the steam chamber is connected to a heat radiating section separate from the heat receiving section through separate piping. 1. A liquid supply device for a heat receiving section in a separate type heat exchanger, characterized in that the upper end of the tube projects into the steam chamber, and a member having a capillary action is attached from the outer wall of the upper end of the evaporation tube to the inner wall.