JPH0310879B2 - - Google Patents

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a heat exchange device applied to a total heat exchanger, an air conditioner, a cooling tower, an industrial supply/exhaust device, etc. ``Prior art'' related to a fluidized bed heat exchange device in which heat transfer between two fluids is performed using a heat pipe. ,
A heat exchange device that exchanges heat between the two air streams by heat transfer through heat pipes extending between the two partitioned spaces is known.

However, such a heat exchange device performs heat exchange by bringing the airflow into direct contact with the heat pipe, so the efficiency is extremely low, and as a result, it is difficult to obtain the desired amount of heat transfer unless a large number of heat pipes are arranged. This has the disadvantage that the device inevitably becomes larger.

In addition, in order to eliminate this drawback, a known fluidized bed heat exchanger was converted into a heat exchanger, and a mesh net was formed to hold solid particles on the entire surface of the fluidized bed below the heat pipes placed in the fluidized bed. For example, there is a method in which heat exchange is performed by forming a large number of airflow gas inflow holes that also serve as a plate, and bringing the multiphase flow of the airflow and solid particles introduced into the fluidized bed through the inflow holes into contact with the heat pipe. 53-24657, etc.

``Problems to be Solved by the Invention'' However, such a heat exchange device has a structure in which a large number of fluidizing holes are formed over the entire surface of the fluidized bed, regardless of the placement position of the heat pipe. Since the movement of the inertial force in the direction becomes non-uniform and there are parts that undergo heat exchange with the heat pipe and parts that do not, it does not lead to a particular improvement in the heat transfer coefficient compared to the case of air exchange.

In addition, in the above device, since the inflow holes are formed over the entire surface of the fluidized bed, the pressure loss of the fluidized bed becomes large, and the power of the fan for suctioning the air flow tends to become large.

In order to solve this problem, if the bed height of the fluidized bed is lowered, it is difficult to obtain a stable and uniform fluidized state, and channeling (airflow blow-by phenomenon) occurs in a part of the fluidized bed, which impedes heat transfer. The problem is that the efficiency is significantly reduced.

The technical problem to be solved by the present invention is to provide a heat exchange device in which a heat pipe is disposed within the fluidized bed, while significantly improving heat transfer efficiency without increasing the pressure loss of the fluidized bed. The purpose is to provide a heat exchange device that can

"Means for Solving the Problems" In order to achieve the above technical problems, the present invention (1) extends a heat pipe between a pair of partitioned spaces through which two fluids having a relatively different enthalpy can pass. In addition, within the pair of partitioned spaces,
In a heat exchange device in which a fluidized bed is formed by accumulating solid particles in at least one partitioned space, a group of bare tubular heat pipes is arranged in one or more stages in the fluidized bed, and the heat pipe group is arranged in one or more stages. At least immediately below the heat pipe located on the lower stage side, there is a band-like structure in which the fluid passage area is gradually reduced from the bottom to the top, and the opening width at the end is set to be smaller than the diameter of the heat pipe. A fluidized bed heat exchange device is provided, characterized in that a slit hole is arranged so that a high-speed airflow after passing through the slit hole can circulate around the bare tubular heat pipe together with the solid particles.

In addition, when two fluids with a relative enthalpy difference are both air flows, as in a total heat exchanger,
A fluidized bed based on the above structure is formed in both of the pair of partitioned spaces, and when one of the two fluids is a water flow and the other is an air flow, as in a cooling tower,
It is sufficient to form a fluidized bed based on the above structure only in the partition space through which the air flow passes.

"Operation" According to the present technical means, the fluid passage area is gradually reduced so that the accelerated airflow passes through the fluidized bed, so pressure loss is significantly reduced compared to the conventional fluidized bed. Moreover, since the heat pipe is placed directly above the slit hole, the high-speed airflow circulates along the circumferential surface of the heatpipe, which is the so-called Coanda effect, and due to the inertial movement of the multiphase flow consisting of solid particles and airflow. The heat transfer takes place smoothly, and as a result, the heat transfer efficiency is several orders of magnitude higher (7-9
times) can be improved.

In this case, if a configuration is adopted in which the heat pipe is provided with fins, the solid particles will not move smoothly in the axial direction during the circulation, making it impossible to perform smooth heat exchange. Therefore, in the present invention, the heat pipe is a bare tube.

"Embodiments" Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of the invention, but is merely an illustrative example.

1 to 4 each show a total heat exchanger according to an embodiment of the present invention.

This device forms a pair of partition spaces 2 and 3 on the left and right sides through a partition plate 1, and has exhaust ports 2a and 3a and air intake ports 2b and 3b to which fans 4 are attached on the top and bottom sides, respectively. The partition spaces 2 and 3 are configured to allow fresh air and exhaust air to pass through them.

A fluidized bed consisting of a group of micro glass spheres and other solid particles 5 is formed in both the partition spaces 2 and 3, and a fluidized bed is formed in the fluidized bed, passing through the partition plate 1 and extending horizontally between the two fluidized beds. multiple heat pipes 6A, 6B
are arranged in multiple stages at predetermined intervals.

Below the heat pipes 6A and 6B, there is a plate-like member 8 in which a large number of slit holes 7 are formed in parallel as means for increasing the speed of air flow, and further below the plate-like member 8 there is a mesh net 9 for holding the solid particle group 5 and other parts. Solid particle retention means are arranged.

Next, each of the above members will be explained in detail.

The heat pipes 6A and 6B are formed of bare tubes,
As shown in FIG. 4, the multiphase flow passing through the circumferential surface of the heat pipe 6A located at the lower stage flows into the heat pipe 6B located at the upper stage.
They are arranged parallel to each other so that they reach the bottom surface.

As shown in FIGS. 3 and 4, the slit holes 7 are arranged horizontally so as to be located directly below the heat pipes 6A located at the lower stage, and are directed from the lower opening 7a to the upper opening 7b so that the flow path passes through. The area is gradually reduced, and the width of the upper opening 7b is made smaller and the diameter of the heat pipes 6A, 6B is smaller.

In addition, the gap between the mesh nets 9 of the plate member 8 forming the slit hole 7 is made narrow enough that solid particles that have fallen in the gap during the passage of the air flow will not remain. The solid particle group 5 (upper end opening 7b) deposited on the mesh net 9 during the stoppage
However, when the fan 4 starts operating, it is immediately returned to the fluidized bed.

According to this embodiment, the airflow flowing into the slit hole 7 from the lower opening 7a is gradually accelerated in flow velocity to become a high-speed airflow and is ejected from the upper opening 7b, and the high-speed airflow is mixed with the solid particle group 5. The flow passes along the circumferential surfaces of the heat pipes 6A, 6B and circulates above the heat pipes 6A, 6B while rotating downward again (Coanda effect).
The thermal energy possessed by the high-speed airflow is transferred to the heat pipes 6A, 6B using the solid particle group 5 as a heat transfer medium, and the heat is smoothly transferred between the fresh air and the exhaust air flow via the heat pipes 6A, 6B. It will be held in Furthermore, in the above embodiment, since the mesh net 9 is disposed below and upstream of the plate-shaped member 8, the airflow passes through the mesh net 9 at a slow speed before becoming a high-speed airflow, and the mesh net 9 Pressure losses occurring during passage are significantly reduced.

Note that the heat pipes 6A and 6B may be arranged exactly above the slit hole 7, or may be slightly shifted from each other. For example, in the case of the heat pipes 6A and 6B arranged above and below, It is preferable that the airflow flows along the circumferential surface of the lower heat pipe 6A and hits the circumferential surface of the upper heat pipe 6B above it.

"Effects of the Invention" As described above, according to the present invention, even though a cold storage heat layer is formed using a fluidized bed, the pressure loss of the fluidized bed does not become so large and the heat transfer efficiency is significantly improved. A heat exchange device that can be used is obtained. It has various effects such as

[Brief explanation of the drawing]

1 to 4 each show a heat exchange device according to an embodiment of the present invention, in which FIG. 1 is a front sectional view, FIG. 2 is a side sectional view, and FIGS. 3 and 4 are airflow flows. They are a sectional view and an enlarged perspective view of a main part, showing the state.

Claims (1)

[Claims] 1. A heat pipe is installed between a pair of partitioned spaces through which two fluids having a relatively different enthalpy can pass, and at least one of the pair of partitioned spaces is filled with a solid. In a heat exchange device in which a fluidized bed is formed by accumulating a group of particles, a group of bare tubular heat pipes is arranged in one or more stages in the fluidized bed, and at least on the lower side of the group of heat pipes. Immediately below the heat pipe, a band-shaped slit hole whose fluid passage area is gradually reduced from the bottom to the top through solid particles, and whose opening width at the end is set to be smaller than the diameter of the heat pipe, is arranged. A fluidized bed heat exchange device characterized in that a high-speed airflow after passing through a slit hole can circulate around the circumferential surface of a bare tubular heat pipe together with the solid particles.