JP2002257439A - Defrosting apparatus for cold generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optimum defrosting apparatus optimum for application to a cold generator such as a freezer in which a generator hot gas defrosting system having greater energy saving effect is constructed by integrally linking several cooling units. SOLUTION: A heat storage tank 2 filled with a cooling solution is included in each of several cooling units 1, and a water supply pipe 31 and a drain pipe 32 are connected to each heat storage tank 2 to couple base ends thereof to an outlet side end of an air cooling condenser 4 and an inlet side end of the same. Hereby, a circulation passage for the cooling solution is formed between the heat storage tanks 2 of the respective cooling units 1 to couple the respective cooling units 1 for a heat exchanging. A pump 5 is mounted on the inlet side piping of the heat storage tank 2 to circulate the cooling solution shared by the respective cooling units 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold air generator provided with a defrosting mechanism of a type in which when frost adheres to a cooling coil, a refrigerant gas for defrosting is passed through the cooling coil and the condensation heat removes the frost. In particular, the present invention relates to a defroster for a cool air generator in which several cooling units are linked and integrally formed.

[0002]

When the moisture in the air condenses on the surface of the cooling coil to form frost, and the thickness of the cooling coil gradually increases, not only the thermal conductivity decreases, but also the air passage is narrowed. As a result, convection is hindered and the cooling capacity of the cooling coil is extremely reduced. This generates a lot of moisture,
This is a problem that always occurs in cold air generators with low temperatures, and effective defrosting measures must be taken. Note that the cold air generator refers to a device that generates cold air, such as a refrigerator, an air conditioner (air conditioner), and a cooler.

[0003] Defrosting methods include an electric heater defrosting method and a watering defrosting method, but all of them involve an increase in the temperature in the freezer, and thus the cooling efficiency is reduced. On the other hand, a hot gas defrost method that generates hot gas using a heat source or the like in a freezer and flows the hot gas into a cooling coil to defrost is a powerful defrosting method that is excellent in heat efficiency and has a large energy saving effect. .

On the other hand, since a required number of refrigerators can be operated in accordance with a load, the cooling efficiency is high and the temperature in the refrigerator can be controlled uniformly. . In addition, since a single unit or a plurality of cooling units can be sequentially selected and defrosted from among the plurality of cooling units, fluctuations in the internal temperature can be suppressed.

Accordingly, an object of the present invention is to provide a defrosting apparatus which is most suitable when a hot gas defrosting method having a large energy saving effect is applied to a cold air generating apparatus in which several cooling units are linked and integrally formed. It was done.

[0006]

In order to achieve the above object, the present invention is configured as follows.

That is, according to the first aspect of the present invention, several cooling units are installed, and each cooling unit is provided with a heat storage tank filled with a cooling liquid, and the heat storage tank is provided with a condenser and re-evaporation for defrosting. A defrosting device that accommodates a coil, connects a cooling liquid circulation path to a heat storage tank of each cooling unit, and connects the heat storage tanks so that they can exchange heat with each other. The invention according to claim 2 is provided with a heating heat storage tank communicating with the heat storage tank, accommodating a heating coil in the heating heat storage tank, and introducing means for introducing hot water of the heating heat storage tank into the heat storage tank, The defroster according to claim 1, wherein when the temperature of the cooling coil of the cooling unit does not reach the predetermined temperature during the defrosting operation, the hot water of the heating heat storage tank flows into the heat storage tank. The invention according to claim 3 is characterized in that a trap is provided in a pipe between the cooling coil of the cooling unit and the liquid / gas separation tank, and a pipe branched from the lowermost part of the trap is connected to the reevaporation coil. Defroster.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a piping diagram of a refrigerator embodying the present invention. The refrigerator has heat storage tanks 2 each filled with a cooling liquid in several cooling units 1, and a water supply pipe 31 and a drain pipe 32 are connected to each of the heat storage tanks 2, and the base ends thereof are on the outlet side of the air-cooled condenser 4. Connect to the end and the inlet end. This allows
A cooling liquid circulation path is formed between the heat storage tanks 2 of the cooling units 1, and the cooling units 1 are connected so as to be able to exchange heat. In addition, pumps 5 are respectively attached to the inlet side pipes of the heat storage tank 2 to circulate the cooling liquid shared between the cooling units 1.
As the coolant, antifreeze is used in consideration of winter operation. The air-cooled condenser 4 is an air-cooled (not necessarily air) heat exchanger that can spray water. The defrosting method of the refrigerator is a sequential defrost method in which each cooling unit 1 is sequentially defrosted.

FIG. 2 shows a piping diagram of a cooling unit embodying the present invention. The cooling unit 1 includes a heating coil 12, a condenser 13, and a liquid receiver 1 on a high pressure side pipe 11 a of the compressor 11.
4. The auxiliary liquid receiver 15 and the expansion valve 16 are connected, and the cooling coil 17 and the liquid / gas separation tank 1
8 are connected to form a cooling circuit, and the re-evaporation coil 19 is connected to the cooling coil 17 to form a defrosting circuit.

The expansion valve 16 has a distributor 1 at its outlet side pipe.
6a, and a branch pipe 16b branched from the distributor 16a
Are respectively connected to the inlet-side end of the cooling coil 17.

The re-evaporation coil 19 has a one-way valve 19a and a header 19b for hot gas supply connected to the outlet side pipe. On the other hand, the valve 19a has the cooling coil 17 attached thereto.
Avoid unnecessary pressure drop of the inhaled gas. Cooling coil 17
At the inlet and outlet, there is a slight pressure difference due to the internal resistance of the gas passing through the cooling coil 17, and the one-way valve 19 a is attached because the suction gas does not pass through the cooling coil 17. The header 19b has a plurality of backflow prevention tubes 19 at one end.
c and connect the end of the backflow prevention pipe 19 c to the cooling coil 17.
To the inlet end of each coil.

The backflow prevention tube 19c is provided with a U-shaped bent portion in the middle thereof. The bent portion increases the surface area by being bent, promotes the vaporization of the refrigerant liquid, increases the resistance, and prevents the backflow, and may be bent not only in the U shape but also in the S shape. .

The cooling coil 17 includes a liquid / gas separation tank 18
A U-shaped trap 17a is provided in the pipe between
The pipe 17b branched from the lowermost part of 7a is connected to the re-evaporation coil 1
Connect to 9.

The liquid receiver 14 is provided with a liquid pipe solenoid valve 14a at the outlet side pipe and connected to the auxiliary liquid receiver 15. Auxiliary liquid receiver 15 (may not be used when liquid receiver 14 is also used)
Stores a certain amount of refrigerant liquid necessary for defrosting. The liquid pipe solenoid valve 14a is closed during the defrosting operation and the liquid receiver 14a is closed.
To prevent the liquid from flowing into the auxiliary liquid receiver 15.

The auxiliary liquid receiver 15 has a thermoelectric solenoid valve 15a for preventing supercooling at one of the outlet pipes (may be omitted).
Is connected to the expansion valve 16. Also, a defrosting solenoid valve 15b is provided at the other end of the outlet side pipe so that the re-evaporation coil 19b is provided.
To the inlet end of the The defrost electromagnetic valve 15b is opened during the defrost operation to allow the refrigerant liquid in the auxiliary liquid receiver 15 to flow into the reevaporation coil 19.

The liquid / gas separation tank 18 separates the liquid condensed in the cooling coil 17 during the defrosting operation into the gas and returns, and receives the liquid bag at the time of starting. At the bottom of the liquid / gas separation tank 18, the heat storage tank 2 is divided into two, and a heating heat storage tank 21 and a cooling heat storage tank 22 are provided. The heat storage tank 21 accommodates the heating coil 12, thereby heating the cooling liquid therein and storing hot water. Cooling heat storage tank 2
2 accommodates the condenser 13 and thereby cools and liquefies the refrigerant gas during the cooling operation. The re-evaporation coil 19
The liquefied gas during the defrosting operation is heated and vaporized. A communication pipe 23 is provided between the heating heat storage tank 21 and the cooling heat storage tank 22, and a pump 24 is attached thereto.

The refrigerator embodying the present invention is configured as described above. During cooling, the high-pressure refrigerant gas discharged from the compressor 11 of the cooling unit 1 is heated by the heating coil 12 to the heat storage tank 2.
1 is heated and then reaches the condenser 13 where it is liquefied.
4 and into the auxiliary receiver 15. Further, the pressure drops through the thermo-electromagnetic valve 15a and the expansion valve 16 to become a mist state, and the cooling coil 1 passes through the branch pipe 16b from the distributor 16a.
7 is supplied to each coil. The refrigerant evaporates in the cooling coil 17 and cools the surroundings into a gaseous state.
After flowing into the liquid / gas separation tank 18 via 7a, it is sucked by the compressor 11 and circulated. This cooling coil 1
The air cooled in 7 is blown out by the fan 17c to be cooled.

At the time of defrosting, the cooling unit 1 is stopped to close the liquid pipe solenoid valve 14a and open the defrost solenoid valve 15b. As a result, the liquefied gas in the auxiliary liquid receiver 15 is removed from the reevaporation coil 19.
And is vaporized by being heated by the heat of the cooling heat storage tank 22. The vaporized hot gas is supplied to each coil of the cooling coil 17 from the header 19b via the one-way valve 19a, where it is liquefied and defrosted by its condensation heat. The liquefied hot gas becomes heavy and flows down to the trap 17a.
And enters the re-evaporation coil 19 through a pipe 17b branched from the lowermost portion of the storage tank, re-evaporates by the heat of the cooling heat storage tank 22, and circulates this. This cycle is repeated until the temperature of the cooling coil 17 reaches a predetermined temperature. Cooling coil 17
If the temperature does not reach the predetermined temperature within a certain period of time, the pump 24 is operated to flow the hot water in the heating heat storage tank 21 into the cooling heat storage tank 22 to increase the temperature. At this time, the pump 5 attached to the inlet of the cooling heat storage tank 22 stops. In addition, the pump 5 is stopped when the inside of the refrigerator is cooled, and is operated at all other times to circulate the coolant in the cooling heat storage tank 22 to cool the condenser 3. Also, this cooling unit 1
The operation is stopped at the time of defrosting, so that there are few troubles and it is safe. In addition, the said defrosting apparatus is applicable not only to a refrigerator but to a cool air generator, such as an air conditioner.

[0020]

As described above, in the defroster of the present invention, the circulation path of the cooling liquid is connected to the heat storage tanks of several cooling units. Therefore, according to the present invention, since several cooling units share the cooling liquid, even if the cooling unit during the defrosting operation cools the cooling liquid, the cooling unit during the cooling operation warms this, and the entire cooling unit is cooled. Thermal efficiency can be improved in a well-balanced manner. Further, by sharing the cooling liquid, the heat storage tank of each cooling unit can be made smaller, and the cooling unit can be downsized. In addition, if air circulation means is provided in the circulation path, defrosting can be efficiently performed in a short time when the outside air temperature is high. In addition, since the cooling liquid in the circulation path does not come into contact with the outside air, it is not necessary to clean the piping of each cooling unit or the like, and the operating cost can be reduced.

Further, the defrosting device of the present invention is provided with a heat storage tank connected to the heat storage tank, and when the temperature of the cooling coil does not reach the predetermined temperature during the defrosting operation, the hot water in the heat storage tank is stored in the heat storage tank. Into the tank. Therefore, according to the present invention, the temperature of the heat storage tank cannot be raised too much during the defrosting operation in relation to the cooling unit during the cooling operation, but the hot water of the heating heat storage tank is temporarily stored in the heat storage tank. By flowing into
The final finishing of the defrosting operation can be reliably performed in a short time.

Further, in the defroster of the present invention, a trap is provided in a pipe between the cooling coil of the cooling unit and the liquid / gas separation tank, and a pipe branched from the lowermost part of the trap is connected to the reevaporation coil. Therefore, according to the present invention, since the gas is flowing during the cooling operation, the liquid and oil accumulated in the reevaporation coil are returned to the cooling circuit, and the refrigerant liquefied by the cooling coil is reevaporated again during the defrosting operation. The important role of returning to the coil can be simultaneously performed with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a piping diagram of a refrigerator embodying the present invention.

FIG. 2 is a piping diagram of a cooling unit embodying the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling unit 11 Compressor 11a High pressure side piping 11b Low pressure side piping 12 Heating coil 13 Condenser 14 Liquid receiver 14a Liquid tube solenoid valve 15 Auxiliary receiver 15a Thermo solenoid valve 15b Defrosting solenoid valve 16 Expansion valve 16a Distributor 16b Branch pipe 17 Cooling coil 17a Trap 17b Pipe 17c Fan 18 Liquid gas separation tank 19 Re-evaporation coil 19a One-way valve 19b Header 19c Backflow prevention pipe 2 Heat storage tank 21 Heat storage tank 22 Cooling storage tank 31 Water supply pipe 32 Drain pipe 4 Air cooling condenser 5 pump

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[Procedure amendment]

[Submission date] March 5, 2001 (2001.3.5)

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

Claims (4)

[The claims] 1. A plurality of cooling units are provided. Each cooling unit is provided with a heat storage tank filled with a cooling liquid, and the heat storage tank houses a condenser and a re-evaporation coil for defrosting. A defroster for a cool air generator, wherein a cooling liquid circulation path is connected to a heat storage tank of a unit, and the heat storage tanks are connected so as to exchange heat with each other. 2. A heating heat storage tank communicating with the heat storage tank is provided, a heating coil is housed in the heating heat storage tank, and introduction means for introducing hot water of the heating heat storage tank into the heat storage tank is provided. 2. The defrosting device for a cool air generator according to claim 1, wherein, when a temperature of a cooling coil of the cooling unit does not reach a predetermined temperature during a defrosting operation, hot water of the heating heat storage tank flows into the heat storage tank. 3. The cool air according to claim 1, wherein a trap is provided in a pipe between a cooling coil of the cooling unit and the liquid / gas separation tank, and a pipe branched from a lowermost portion of the trap is connected to the reevaporation coil. Generator defroster. 4. The defrosting device for a cool air generator according to claim 1, wherein the cool air generator is a refrigerator.