JPS599039B2 - gas cooling device - Google Patents

Description

Detailed Description of the Invention This invention sprays a water-repellent liquid that has been cooled by heat exchange with the cold temperature of a refrigeration device onto a filling layer, and prevents frost by exchanging heat between the water-repellent liquid film on the surface of the filling material and the air. This is a gas cooling device that obtains low-temperature air while suppressing the generation of air, and is particularly suitable for commercial refrigerators.

Conventional low-temperature air coolers usually have a configuration in which a refrigerant is passed through the tubes of a plate-fin type heat exchanger, and the air is cooled by exchanging heat with the air on the tube outer surface and plate fin surface.

In this type of air cooler, when the air temperature is cooled to 5°C or less, the heat transfer surface is usually 0°C or less.

Under these conditions and when the dew point of the air is higher than the temperature of the heat transfer surface, moisture in the air solidifies on the heat transfer surface to form a frost layer.

This frost layer gradually grows, increasing ventilation resistance and at the same time increasing the thermal resistance between the air and the refrigerant. Therefore, these air coolers are equipped with a defrosting mechanism that stops the operation of the air cooler at regular intervals to defrost the air. Frost operation must be carried out.

As a method of continuously operating an air cooler while avoiding defrosting operation, there is a brine spraying method in which ethylene glycol, which is used as brine, is sprayed onto the heat exchanger to prevent frost formation.

This system consists of an air cooler, a refrigeration system, and a brine concentrator.

The brine spread over the heat exchanger of the air cooler is cooled on the heat transfer surface of the heat exchanger cooled by the refrigerant from the refrigeration system, and at the same time exchanges heat with the air to be cooled to cool the air.

Brine is an aqueous solution of ethylene glycol or the like and has water absorption properties, so it absorbs water during this heat exchange process.

A concentrator condenses this diluted brine, and usually performs condensation by heating with a heater and by spraying the brine and bringing it into contact with ventilated air.

In this brine dispersion method, the air cooler usually adopts a plate-fin type or multi-tube type in order to satisfy the characteristics as a heat exchanger.

In the case of the plate fin type, it is not easy to completely wet the heat transfer surface with brine, and the amount of brine to be sprayed is extremely large.

In the case of a multi-tube type, it is difficult to secure the necessary heat transfer area and the size of the air cooler becomes large.

In addition, the physical properties of brine change due to moisture absorption.

The amount of brine sprayed varies depending on the constituent material of the air cooler, but it varies greatly depending on the viscosity of the brine.

Therefore, the cooling capacity of this device changes depending on the operating conditions.

Similarly, the capacity of the concentrator changes, making its control as an air cooling device complicated.

Additionally, a heater is essential as a concentrator.

Particularly when there is a lot of moisture in the air, this heater power becomes a non-negligible amount of power for the entire device.

The present invention provides an air cooler with a compact structure that takes into consideration only direct heat exchange between the water repellent liquid and the air by dispersing the water repellent liquid cooled by the cold of the refrigeration equipment onto the packed layer. The aim is to obtain an air cooler with low power consumption and stable performance by dispersing aqueous liquid.

An embodiment of the present invention shown in FIG. 1 will be described in detail below.

In Figure 1, 11 is a water-repellent liquid spraying device, and 12 is a filling layer that performs heat exchange between the air and the water-repellent liquid. A material with low resistance can be used.

In the filling layer, heat exchange occurs through direct contact between the water repellent liquid and the air, so the thermal conductivity of the material of the filling layer is not an issue, and an inexpensive material is used in consideration of contact resistance and wettability with the water repellent liquid. Plastic etc. can also be used.

13 is an eliminator made of gold steel or the like with large voids that collects water-repellent liquid in the air.

14 is a water-repellent liquid tank, and 16 is a suction duct.

18 is a pump that circulates the water repellent liquid.

Thus, 11, 12, 13, 14, 16, and 18 constitute an air cooler 10.

20 is a separation device, which includes a heat recovery heat exchanger 21 and a pump 22.
, consisting of a blower that sends air.

A refrigeration system 30 includes a compressor 31, an expansion valve 32, and a heat exchanger 33.

The water repellent liquid is taken out from the water repellent tank 14 by a pump 18, cooled in a heat exchanger 19, and sent to the water repellent liquid spraying device 11.
sent to and distributed.

The sprayed water-repellent liquid drips onto the surface of the filling layer 12, exchanges heat with the air on the surface of the filling material, and accumulates in the water-repellent liquid tank 14.

Water vapor in the air condenses during the cooling process in the filled layer 12 and falls into the water-repellent liquid tank 14.

Since the water-repellent liquid tank 14 is usually heat-insulated, the temperature rise of the water-repellent liquid in the water-repellent liquid tank 14 is small. Therefore, the water that falls is obtained in the form of ice, and the difference in specific gravity between oil and water is reduced. As a result, ice-like water or a water-repellent liquid containing a large amount of ice-like water accumulates in the lower part of the water-repellent liquid tank 14.

By taking out the outlet pipe to the water-repellent liquid spraying device 11 from the upper part of the water-repellent liquid tank 14, the water-repellent liquid sprayed onto the filling layer 12 always contains no water, and the properties of the water-repellent liquid are maintained. is always constant.

'In this way, an air cooler with stable performance is achieved.

Similarly, the extraction pipe leading to the separation device 20 is connected to the water repellent liquid tank 14.
Efficient oil-water separation is achieved by taking out the oil from the bottom of the tank.

An effective method for the separation device 20 is a flotation method in which oil and water are separated by forced air ventilation.

As a water repellent liquid, naphthenic oil has properties that are effective for this device.

Generally, oil has a high viscosity and is considered difficult to spray onto solids such as packed layers.

It is believed that the viscosity increases rapidly especially at low temperatures, but naphthene-rich refined products (such as high-pressure insulating oil and refrigeration oil (IGS)) have sufficient fluidity even at low temperatures. It was also found that the stability against water is high.

Figure 2 shows the temperature dependence of the kinematic viscosity coefficients of various fluids.

In the above embodiments, the oil/water separator uses a flotation method, but any current technology including this method, such as a centrifugal separation method, can be applied.

Further, in the air cooler, the direction of the air flow is opposite to the direction in which the water-repellent liquid is distributed, but the direction of the air flow may be the forward direction or the right angle direction.

As described above, the present invention provides a low-temperature air cooler,
It has a structure that suppresses frost formation and does not require defrosting operation.

And compared to the brine dispersion method currently in use,
There are almost no restrictions on the material and shape of the filling layer, and an extremely compact structure can be achieved using any material.
Furthermore, a gas cooling device that is easy to control and consumes little power can be obtained.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the temperature dependence of the kinematic viscosity coefficient of a fluid. In the figure, 10 is an air cooler, 11 is a water-repellent liquid distribution device, 12 is a packed layer, 13 is an eliminator, 14 is a water-repellent liquid tank, 15 is a fan, 16 is a suction duct, 17 is a discharge duct, and 18 is a pump , 19 is a heat exchanger, 20 is a separation device,
21 is a heat exchanger, 22 is a pump, 23 is a blower, 30
31 is a compressor, 32 is an expansion valve, and 33 is a heat exchanger.

Claims (1)

[Claims] 1. A water-repellent liquid spraying device that sprays a water-repellent liquid, a filling layer that receives the water-repellent liquid sprayed from the water-repellent liquid spraying device, and performs gas-liquid contact between the water-repellent liquid and gas, and the above-mentioned gas-liquid contacting layer. A water-repellent liquid tank that receives the water-repellent liquid afterwards, a water-repellent liquid supply path that supplies the water-repellent liquid in the water-repellent liquid tank to the water-repellent liquid spraying device, and a water-repellent liquid supply path that supplies the water-repellent liquid in the water-repellent liquid tank to the water-repellent liquid spraying device; A gas cooling device comprising a heat exchange device for cooling and a separation device for separating and removing impurities in the water repellent liquid in the water repellent liquid tank.