JPS5924790B2 - heat exchange equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to improve the performance of heat exchangers such as condensers and radiators of air conditioners. This invention relates to a heat exchanger.

As a means to improve the heat transfer performance of heat exchangers, there is a method that utilizes the latent heat of vaporization of the droplets by scattering minute droplets on the heat transfer surface along with the airflow, and is usually called an evaporative heat exchanger. There is.

Conventionally, the method for spraying droplets on this type of evaporative heat exchanger was to spray water from above the heat exchanger using an electric pump or the like to pump water from a water tank located at the bottom of the heat exchanger. There was something.

However, with this method, the water droplets sprayed are too large and cannot be sprayed uniformly over the entire surface of the heat exchanger, and the liquid film is too thick in the sprayed area, preventing evaporation. There were drawbacks such as:

Another method that has been devised is to immerse a portion of the rotating disk in liquid and make the droplets splash and hit the heat exchanger, but this method uses the centrifugal force of the rotating disk. Due to the nature of the equipment used, the droplets from the disk only fly in the tangential direction of the disk, so it was not possible to spray droplets uniformly over the entire surface of the heat exchanger.

Moreover, these means only disperse droplets,
Since it does not have an air blowing function, it is necessary to install an air blower in addition to the sprinkler device mentioned above in order to improve the heat transfer performance of the heat exchanger and generate airflow to promote the evaporation of droplets. Ta.

The present invention solves the above-mentioned conventional drawbacks, and one embodiment thereof will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a heat exchange device according to an embodiment of the present invention.

1 is a heat exchanger, 2 is a sirocco fan attached to the shaft 3 of a drive motor (not shown), which sucks air from the axial direction (perpendicular to the page) and blows it in the direction of heat exchanger 1. .

4 is this sirocco fan 20 casing, the lower part of which is used as a liquid reservoir.

Further, a water conduit 6 is attached to the lower part of the casing 4 via a control valve 5, and the control valve 5 is controlled by a liquid level controller 7 attached within the casing 4.

The liquid level controller 7 uses a liquid level sensor 8 to horizontally narrow the liquid level, opens the control valve 5 when the liquid level falls below a set value, and throttles the control valve 5 when the liquid level rises above the set value. Operate.

In the above configuration, the operation thereof will be explained next.

As described above, the liquid level controller 7 controls the liquid level inside the casing 4 to make it lower than the outer circumference of the sirocco fan 2 by mm.

Therefore, even when the drive motor (not shown) is energized to rotate the sirocco fan 2, there is no liquid resistance and the fan starts rotating with a low starting torque.

As the sirocco fan 2 rotates, air is sucked in from the axial direction (direction perpendicular to the plane of the paper), creating an airflow in the direction of the white arrow.

At the same time, the liquid level in the casing 4 violently ripples due to the wind pressure and the vibrations caused by the 20 rotations of the sirocco fan.

Some of these waves become fine droplets and are suspended in the airflow, and the droplets that adhere to the sirocco fan 2 are scattered by centrifugal force and suspended in the airflow, or are directly heated. It reaches exchanger 1.

In this way, the minute droplets Qζ reaching the heat exchanger 1 hit almost the entire surface of the heat exchanger 1 and form a thin, almost uniform liquid film.

The evaporation of this liquid film is promoted by the air blown by the sirocco fan 2, and evaporates efficiently.

Therefore, the extremely large latent heat of vaporization (approximately 600 kcalAq in the case of water) due to evaporation of this liquid film is utilized for cooling the heat source fluid flowing inside the heat exchanger 1.

Furthermore, the air that promotes the evaporation of the liquid film also exchanges heat when passing through the heat exchanger 1, and can be used to cool the heat source fluid.

FIG. 2 shows the change in the amount of droplets scattered when the distance δ between the liquid level in the casing 4 and the outer periphery of the sirocco fan 2 is changed in the heat exchanger shown in FIG. 1.

As is clear from this figure, it can be seen that the amount of scattered droplets decreases in almost inverse proportion to the increase in distance δ.

Furthermore, since the heat exchange device of the present invention utilizes the latent heat of evaporation of the liquid film formed on the surface of the heat exchanger 10, the liquid film is adjusted by increasing or decreasing the amount of scattered droplets, and the evaporation is It is possible to change the amount of liquid used.

That is, by changing the distance between the outer periphery of the sirocco fan 2 and the liquid level, the heat exchange capacity of the heat exchanger 1 can be easily adjusted.

Although the above embodiment has been described using the sirocco fan 2 as the centrifugal blower, it is clear that other blowers such as a friction disk fan may also be used.

Furthermore, in the above embodiment, the liquid level controller 7 and the control valve 5 are used to control the liquid level in the casing 4, but this is not possible with a simple liquid level side m such as a ball tap or an overflow device. It is clear that it may be used.

Further, it is clear that the liquid reservoir may be formed by partially deforming the casing without being limited to the shape of the lower part of the casing.

As is clear from the above description, the present invention provides a heat exchange device including a centrifugal blower and a heat exchanger, in which the lower part of the casing of the centrifugal blower is used as a liquid reservoir, and the lower part of the casing of the centrifugal blower is used as a liquid reservoir. Since the heat exchange device is characterized in that it is equipped with a controller that controls the liquid level to be below the outer circumference of the rotor of the centrifugal blower, the rotor of the centrifugal blower will not be submerged in the liquid. The liquid does not create resistance during startup (it can be started smoothly with a small starting torque, and even during stoppage, a portion of the rotor is not eroded by the fluid).

In addition, since a centrifugal blower is used, almost all of the heat exchanger is Can form a uniform thin liquid film on the surface,
Furthermore, since the evaporation of this liquid film is promoted by the airflow, an excellent effect is achieved in that the extremely large latent heat of vaporization can be used for cooling the fluid flowing inside the heat exchanger.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a heat exchange device according to an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the characteristics of the amount of droplets scattered. 1...Heat exchanger, 2...Sirocco fan, 4...Casing, 5...Control valve, 6...Water pipe, 7...Liquid level controller,
8...Liquid level sensor.

Claims (1)

[Scope of Claims] 1. In a heat exchange device comprising a centrifugal blower and a heat exchanger, the lower part of the casing of the centrifugal blower is used as a liquid reservoir, and the liquid level in the casing is controlled by the centrifugal blower. A heat exchange device characterized in that a controller is provided below the outer periphery of a rotor of a blower. 2. Claim 1, characterized in that the controller adjusts the amount of liquid droplets scattered by changing the distance between the liquid level in the casing of the centrifugal blower and the outer periphery of the rotor of the centrifugal blower. The heat exchange device described.