JPH0345314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fluidized bed cooling device, and more particularly to a fluidized bed cooling device with excellent heat transfer characteristics from a heat transfer tube to the surroundings.

[Prior Art] As a liquid or gas cooling device, a type in which a fluid is passed through a heat transfer tube and air is passed outside the heat transfer tube for air cooling is well known. In this type of cooling device, measures are often taken such as providing heat radiation fins in the heat transfer tube or making the tube material high in thermal conductivity.

However, in cooling systems that employ such conventional heat transfer tubes, the only fluid that comes into contact with the heat transfer tubes is air, so even if fins are installed or the tube material is improved, the amount of heat dissipated will still be affected. The upper limit has been reached.

The present invention solves the above conventional problems and provides a cooling device in which the amount of heat transferred from the tube to the surroundings is significantly increased.

[Means for Solving the Problems] The fluidized bed cooling device of the present invention has a heat transfer tube disposed in the upper chamber of a fluidized bed container whose interior is divided into upper and lower chambers by a dispersion plate. At the same time, this upper chamber is filled with a fluidizing medium in an amount such that the height of the fluidized bed is such that at least a portion of the heat transfer tube is buried during fluidization. In the present invention, the fluidizing medium is hollow and has pores that communicate between the inside and outside of the particles.

[Function] In the fluidized bed cooling device of the present invention, not only a gas such as air but also a medium fluidized by this gas comes into contact with the heat transfer tube. Therefore, thermal energy is transferred from the surface of the heat transfer tube not only to gases such as air but also to solid media with large heat capacity, and the amount of heat transferred from the heat transfer tube to the surroundings increases significantly, resulting in efficient cooling. It is possible to do so. The present invention uses a fluidizing medium that is hollow and has holes that communicate between the inside and outside of the particles, and this fluidizing medium is lightweight, and sound enters the inside of the fluidizing medium through the holes and is muffled. .

[Example] Examples will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the configuration of a fluidized bed cooling device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a fluidized bed container, and an air dispersion plate 2 is installed in the lower part of the interior thereof in a substantially horizontal direction, so that the interior of the fluidized bed container 1 becomes an upper chamber (fluidized chamber).
3 and a lower chamber (air receiving chamber) 4. A heat transfer tube 5 is disposed within the flow chamber 3, and is configured such that a fluid to be cooled is introduced from one end 5a and a cooled fluid is taken out from the other end 5b. In addition, a fluidizing medium 6 is provided in the fluidizing chamber 3.
is filled. As the fluidizing medium 6, hollow particles having holes that communicate between the inside and outside of the particles are used. The filling amount of the fluidizing medium 6 is such that the height of the fluidized bed is such that at least a portion of the heat transfer tube 5 is buried during fluidization. Preferably, the filling amount is such that all of the heat transfer tubes 5 are buried in the fluidized bed during fluidization.

The air distribution plate 2 may be of any construction as long as it does not allow the fluidized medium 6 to fall into the air receiving chamber 4. In the illustrated embodiment, a short cylindrical member 2c is erected above the openings 2a of a dispersion plate main body 2b in which a large number of openings 2a are opened, and a roof-shaped member 2c is provided opposite to the upper end opening of the cylindrical member 2c. One in which a member 2d is installed is used.

Further, in the apparatus of this embodiment, a louver damper 7 is installed in the upper part of the fluidized bed chamber 3, and is configured to be able to adjust the flow rate of gas passing through the fluidized bed container 1. It also has the role of preventing the fluidizing medium 6 from flying upward. Note that the reference numeral 7a is a shaft member that pivotally supports the louver damper.
Further, a collision plate 8 is installed above the louver damper 7, and when the fluidized medium 6 that has escaped from the flow chamber 3 hits, it bounces the fluidized medium 6 and causes it to fall into the inside of the flow chamber 3. is doing.

In the figure, 1a and 1b are air inlets and outlets provided at the bottom and top of the fluidized bed container 1. In this embodiment, a fan 9 is installed at the inlet 1a, and is driven by a motor 10 to
It is designed to blow air inside.

In the fluidized bed cooling device configured as described above, when the motor 10 is operated to rotate the fan 9, air is introduced into the air receiving chamber 4, and this air passes through the opening 2a of the air distribution plate 2. It enters the fluidization chamber 3 and fluidizes the fluidization medium 6. The air and fluidizing medium 6 come into contact with the heat transfer tube 5 and rise further within the flow chamber 3, taking away heat from the hot fluid that is being passed through the heat transfer tube 5. Most of the fluidized medium 6 forms a fluidized bed, but some of the fluidized medium 6 is entrained by air and rises inside the fluidized chamber 3,
Furthermore, a part of it is bounced off the collision plate 8 and falls into the fluidization chamber 3, forming a fluidized bed again. When the fluidizing medium 6 is particles, a small portion of the particles may be drawn out of the fluidized bed container 1 from the outlet 1b along with air, but they are sent to a particle collection device such as a cyclone. In this case, the collected particles are usually returned to the fluidized bed container 1.

However, since not only air but also the solid fluidizing medium 6 comes into contact with the surface of the heat transfer tube 5, the thermal energy transferred from the fluid to be cooled to the heat transfer tube 5 is transferred to both the air and the fluidizing medium 6. This makes it possible to perform efficient cooling.

As described above, as the fluidizing medium 6, as shown in FIG. 2, particles 11 which are hollow and have holes 11a communicating between the inside and outside of the particles are used, so that the particles are lightweight. , the pressure loss of the fluidized bed is reduced, and the capacity of the motor 10 can be reduced.

The sound generated in the fluidized bed container 1 enters the particles 11 through the holes 11a and is attenuated, thereby producing a sound-deadening effect.

There are effects such as As such particles 11, those made of ceramics such as aluminum oxide (alumina), magnesium oxide, and silicon carbide, and hollow particles made of metals such as stainless steel and copper can be used. Further, the particle size of the particles is preferably about 1 to 2 mm, and the thickness of the particle shell and the pores 11a
The suitable size is about 0.1 to 0.3 mm.
Such hollow particles are filled into the fluidized bed container 1 so that the height of the fluidized bed layer is, for example, about 150 to 300 mm.

In addition, the inventors filled the fluidized bed container 1 with hollow alumina particles (average particle size of about 1.5 mm, shell thickness of 0.2 mm) so that the height of the fluidized bed was about 200 mm. When we conducted an experiment, we found that heat transfer tube 5
It was observed that the overall heat transfer coefficient on the surface was approximately three times that of the case where only air was allowed to flow.

The fluidized bed cooling device of the present invention can be used as a cooling device for various fluids, but as described above, by using a hollow fluidizing medium,
Since it can also have a silencing effect, it can be used in heat recovery devices for exhaust gas from gas turbines and diesel engines.

Although the above description has mainly been made regarding the case where the cooling gas is air, it is clear that the fluidized bed cooling apparatus of the present invention can also use gases other than air as the cooling gas.

[Effects] As detailed above, in the fluidized bed cooling device of the present invention, not only gas but also a solid fluidizing medium with a large heat capacity comes into contact with the surface of the heat transfer tube, making it possible to perform extremely efficient cooling. It is considered possible.

In addition, since particles that are hollow and have holes that communicate between the inside and outside of the particles are used as the fluidizing medium, the particles are lightweight, so the pressure drop in the fluidized bed is small, and the fluid that supplies the fluid to the fluidized bed is The capacity of the drive source (for example, motor) of the distribution device can be reduced.

The sound generated in the fluidized bed container enters the particles through the pores of the particles and is attenuated.
A silencing effect is produced.

Effects such as this are produced.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing the configuration of a fluidized bed cooling device according to an embodiment of the present invention, and FIG.
FIG. 1...Fluidized bed container, 2...Air distribution plate, 5...
Heat transfer tube, 6... Fluidization medium, 7... Louver damper, 8... Collision plate, 9... Fan, 11...
hollow particles.

Claims (1)

[Claims] 1. A fluidized bed container whose interior is divided into upper and lower chambers by a dispersion plate, and a fluidized bed container disposed in the upper chamber of the container, through which a fluid to be cooled is passed. a heat transfer tube, and a fluidizing medium filled in the upper layer in an amount such that the height of the fluidized bed buries at least a portion of the heat transfer tube when flowing, the fluidizing medium being A fluidized bed cooling device characterized by being hollow and having holes that communicate between inside and outside of particles. 2. The fluidized bed cooling device according to claim 1, wherein the fluidizing medium is hollow particles made of ceramic or metal. 3. The fluidized bed cooling device according to claim 2, wherein the particles have a diameter of 1 to 2 mm and a shell thickness of the particles of 0.1 to 0.3 mm. 4. The fluidized bed cooling device according to claim 3, wherein the particles are hollow alumina particles.