JPH06193981A - Refrigerator - Google Patents

Abstract

PURPOSE:To provide a refrigerator in which a normal operation can be performed even when substitute refrigerant having no damage of an ozone layer is sealed in an existing refrigerator. CONSTITUTION:The refrigerator comprises a first memory 15 and a second memory 16 for storing different control constants of refrigerant in an outdoor controller 1 thereof, and a memory changeover switch 14 for switching the memory to be read by the controller 1 according to refrigerant to be sealed. Accordingly, even if refrigerant having different characteristics is used, a normal operation can be performed by altering the control constant according to the refrigerant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating device used in an air conditioner, a refrigerator, etc., and more particularly to a refrigerating device in which different refrigerants can be used.

[0002]

2. Description of the Related Art Control of a refrigerating device used in an air conditioner, a refrigerator or the like is disclosed in Japanese Patent Publication No. 2-45796 and Japanese Unexamined Patent Publication No. 2-230055. A method is known in which the temperature and pressure of each part are detected, and the expansion valve is controlled based on the detected values and the data stored in the control part. Further, as described in Japanese Patent Application Laid-Open No. 2-230054, the temperature and pressure of each part of the refrigeration cycle are detected, and the detected values are compared with the data stored in the control part to judge an abnormality of the refrigeration cycle. It is known how to do it.

[0003]

In the above-mentioned conventional example, when the kind of the refrigerant is changed, it is not taken into consideration.
In recent years, refrigerants used in refrigeration systems, such as R1
It has become clear that chlorine-containing refrigerants such as 2, R22 destroy the ozone layer, and it is forbidden to use them. Instead of these refrigerants, R12 is used as a refrigerant without ozone depletion.
Against R134a, R22 against R32 and R134
A mixed refrigerant of a or a mixed refrigerant of R32 and R125 is known as an alternative refrigerant. However, when the already installed refrigeration system replaces the enclosed refrigerant due to relocation or failure with an alternative refrigerant, the refrigeration system does not operate normally with conventional control constants due to the different refrigerant characteristics. There was a problem.

Further, since the alternative refrigerant does not contain chlorine, the refrigerating machine oil used for R12 and R22 is not compatible, and the refrigerating machine oil flowing out of the compressor is difficult to return to the compressor, so that the refrigerating machine oil is insufficient. Therefore, there is a problem in that lubrication failure of the compressor occurs.

An object of the present invention is to provide a refrigerating apparatus which can perform normal control even when different refrigerants are charged.

[0006]

In order to achieve the above object, the present invention provides a detector for detecting the operating condition of each part of a refrigerating apparatus, a signal from the detector and data stored in a storage device. In the refrigerating apparatus having the controller that operates based on the above, the means for changing the data in the storage device according to the refrigerant used is provided.

[0007]

According to the present invention, by providing the means for changing the data in the storage device of the refrigerating device depending on the refrigerant used, the control constant depending on the kind of the refrigerant can be used even when the refrigerant is changed. The cycle can be operated normally.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioner will be described below as an example of the present invention as a refrigeration system.

FIG. 1 is a control circuit diagram of an air conditioner according to an embodiment of the present invention, FIG. 2 is a system diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention, and FIG. 3 is a refrigerant of an outdoor heat exchanger. It is a temperature distribution diagram.

In FIG. 1, reference numeral 1 is an outdoor controller, which is an inverter circuit 2 for controlling the rotation speed of the compressor 3 and a four-way valve 5.
Four-way valve drive device 4, which switches between air-conditioning operation and heating operation
Outdoor fan drive device 6 for driving the outdoor fan 7, expansion valve drive device 8 for driving the expansion valve 9, discharge refrigerant temperature detector 1
0, the outdoor heat exchanger temperature detector 11, the suction refrigerant temperature detector 12, the outdoor air temperature detector 13, and the first storage device 14 and the second storage device 14 which store different control constants depending on the refrigerant physical properties. A storage device changeover switch 14 for switching the storage device 15 is provided. In addition to the control constants, the second storage device 15 stores oil return operation data at regular operation times. The storage device changeover switch 14 is set on the side of the first storage device 14 that matches the pre-filled refrigerant, for example, R22. Reference numeral 17 denotes an indoor controller, which is an operating device 1 for inputting an operation mode or a set temperature.
8. Indoor fan drive device 1 for driving the indoor fan 20
9, an indoor heat exchanger temperature detector 21, an indoor air temperature detector 22, and an indoor blown air temperature detector 23 are provided.
The indoor controller 17 and the outdoor controller 1 can bidirectionally transfer data, and transfer the operation mode, the output of each detector, and the like.

In FIG. 2, 5 is an outdoor unit,
A compressor 3, a four-way valve 5 that switches the flow direction of the refrigerant between cooling operation and heating operation, an outdoor fan 7 that blows air to an outdoor heat exchanger 25 that functions as a condenser during cooling operation, and an evaporator during heating operation, and expansion. A valve 9, an accumulator 26, and a service valve 27 for charging and discharging the refrigerant in the refrigeration cycle are provided. An indoor unit 28 is provided with an indoor fan 20 that blows air to an indoor heat exchanger 29 that functions as an evaporator during cooling operation and a condenser during heating operation. The indoor unit 28 and the outdoor unit 24 are connected by a gas side pipe 30 and a liquid side pipe 31.

The operation of the air conditioner configured as above will be described.

When the operation device 18 is set to the cooling operation, the indoor fan 20 is turned on, and the indoor controller 17 causes the outdoor controller 1 to perform the cooling operation mode and the set temperature of the indoor unit and the indoor air temperature are detected at a constant cycle. The temperature difference detected by the device 22 is transferred. The outdoor controller 1 causes the four-way valve 4 to operate on the cooling operation side and the outdoor fan 7 via the outdoor fan drive device 6.
Is ON, the expansion valve 9 is set to an opening degree based on the preset data of the first storage device 15 by the expansion valve drive device 8, and the temperature difference sent to the compressor 3 from the indoor controller 17 is set. And the rotation speed calculated from the data stored in the first storage device 15.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 3 passes through the four-way valve 5 and radiates heat in the outdoor heat exchanger 25 to the air blown by the outdoor fan 7 to be condensed. The condensed liquid refrigerant is decompressed by the expansion valve 9 to become a gas-liquid two-phase refrigerant, and is sent to the indoor unit 28 through the liquid side pipe 31. The refrigerant sent to the indoor unit 28 cools the air blown by the indoor fan 20 in the indoor heat exchanger 29, becomes a gas refrigerant, passes through the gas side pipe 30, returns to the outdoor unit 24, and the four-way valve 5 and the accumulator. It returns to the compressor 3 through 26. After the opening degree of the expansion valve 9 is maintained at the set value for a certain period of time, the compressor discharge refrigerant temperature detected by the discharge refrigerant temperature detector 10 is lower than the set temperature stored in advance in the first storage device 15. Is controlled to a value stored in the first storage device 10 according to the temperature difference of the outdoor air temperature detector 13 and the compressor rotation speed. When the temperature detected by the discharge refrigerant temperature detector 10 is higher than the set temperature, the opening degree is controlled so that the discharge refrigerant temperature becomes the set value. A part of the refrigerating machine oil enclosed in the compressor 3 flows out into the refrigeration cycle with the outflow of the refrigerant, but the enclosed refrigerating machine oil is compatible with the refrigerant and the viscosity of the refrigerating machine oil is dissolved by the refrigerant. It falls back to the compressor due to the flow of refrigerant.

When the temperature detected by the outdoor heat exchanger temperature detector 11 becomes higher than the preset temperature stored in the storage device 15 in advance, the compressor 3 is stopped to prevent the compressor from being overloaded. It

Next, the heating operation will be described. When the operation mode of the controller 18 is set to the heating operation, the indoor controller 17
From the above, to the outdoor controller 1, the heating operation mode and the temperature difference detected by the set temperature of the indoor unit and the indoor air temperature detector 22 are transferred to the outdoor controller 1 in a constant cycle. The outdoor controller 1 sets the four-way valve 5 on the heating operation side, the outdoor fan 7 is turned on, the expansion valve 9 is set to the opening degree stored in the first storage device 15, and the compressor 3 is set at the required rotation speed. While being driven, the compressor 3 is driven at the rotation speed calculated from the data stored in the first storage device 15 from the temperature difference sent from the indoor controller 17. The indoor fan 20 is driven to prevent cold air when the temperature detected by the indoor heat exchanger temperature detector 21 reaches or exceeds a set value.

Contrary to the cooling operation, the compressor 3 is operated during the heating operation.
The high-temperature and high-pressure gas refrigerant that exited is the four-way valve 5, the gas side pipe 30
To the indoor unit 28. Indoor unit 28
The gas refrigerant sent to the unit heats the air blown by the indoor fan 20 in the indoor heat exchanger 29 to become a liquid refrigerant, passes through the liquid side pipe 31, returns to the outdoor unit 24, and returns to the outdoor air in the outdoor heat exchanger 25. It absorbs more heat and becomes a gas refrigerant, and the four-way valve 5,
It returns to the compressor 3 through the accumulator 26. After the opening degree of the expansion valve 9 is maintained at the set value stored in the first storage device 15 for a certain period of time, when the compressor discharge refrigerant temperature detected by the discharge refrigerant temperature detector 10 is lower than the set temperature, The opening is controlled so that the temperature difference between the suction refrigerant temperature detector 12 and the outdoor heat exchanger temperature detector 11 becomes the value stored in the first storage device. The temperature distribution of the outdoor heat exchanger 25 at this time will be described with reference to FIG. With a single refrigerant such as R22, the refrigerant flowing into the outdoor heat exchanger 25 flows while evaporating in the pipe, but the refrigerant temperature slightly decreases due to pressure loss. Outdoor heat exchanger temperature detector 1 installed at position X1
1, the outdoor heat exchanger temperature T1 is detected. The refrigerant continues to evaporate and finishes evaporating at the position X2, becomes superheated steam, exits the outdoor heat exchanger, and returns to the compressor. At this time, the suction refrigerant temperature detector 1 provided at the position X3 immediately before the compressor inlet
2, the compressor suction refrigerant temperature T2 is detected. By controlling the expansion valve 9 so that the difference between the suction refrigerant temperature T2 and the outdoor heat exchanger temperature T1 becomes the value stored in the first storage device 15, the air conditioner is operated with high efficiency. . When the temperature detected by the discharge refrigerant temperature detector 23 is higher than the set temperature, the expansion valve is controlled so that the discharge refrigerant temperature reaches the set value, and reliability deterioration due to overheating of the compressor 3 can be prevented. When the temperature detected by the indoor heat exchanger temperature detector 21 becomes higher than the preset temperature stored in the storage device 15 in advance, the compressor 3 is stopped to prevent the compressor from being overloaded.

When a different refrigerant is charged due to a failure or the like, the service valve 27 is opened to collect the enclosed refrigerant, and the vacuum is evacuated. Then, for example, R3 is used as an alternative refrigerant.
A mixed refrigerant containing 30 wt% of 2 and 70 wt% of R134a is charged from the service valve 27. Further, the second storage device 16 is selected by the storage device changeover switch 14. The expansion valve control during the heating operation at this time will be described with reference to FIG. The mixed refrigerant flowing into the outdoor heat exchanger 25 evaporates along the pipe, and the temperature rises due to the characteristics of the mixed refrigerant.
The outdoor heat exchanger temperature detector 11 installed at the position X1 detects the outdoor heat exchanger temperature T3. The refrigerant continues to evaporate and finishes evaporating at the position X2, becomes superheated steam, exits the outdoor heat exchanger, and returns to the compressor. At this time, the suction refrigerant temperature detector 12 provided at the position X3 immediately before the compressor inlet detects the suction refrigerant temperature T4. This suction refrigerant temperature T4
The air conditioner is normally operated by controlling the expansion valve 9 so that the difference between the outdoor heat exchanger temperature T2 and the outdoor heat exchanger temperature T2 becomes the value stored in the second storage device 16. Furthermore, by using the value stored in the second storage device as the setting value of the expansion valve at the time of startup, transient fluctuation is reduced.

Further, the second storage device 16 stores data for performing the oil recovery operation every operation for a certain period of time. When the operating time of the compressor 3 detected by the outdoor control device 1 reaches the time stored in the second storage device 16, the oil return operation is started. The operation will be described with reference to the time chart of the oil return operation in FIG. The compressor 3 is operated for a fixed time Δt1
After the passage of time, the compressor 3 is set to the high-speed rotation speed stored in the second storage device 16 and the expansion valve 9 is fully opened regardless of the operating condition of the refrigeration cycle.

Since the compressor 3 is operated at high speed and the expansion valve 9 is opened, the refrigerant flowing out of the compressor 3 circulates in the refrigeration cycle at high speed. At this time, the refrigerating machine oil that has flowed out of the compressor during normal operation and has been separated from the refrigerant and accumulated in the refrigeration cycle is returned to the compressor by the refrigerant that circulates at high speed. When the oil return operation Δt2 time has elapsed, the operation returns to normal operation.

The set values stored in the second storage device 16 are used as the indoor heat exchanger temperature at which the compressor is stopped during the cooling operation and the outdoor heat exchanger temperature during the heating operation.

As described above, according to this embodiment, even when different refrigerants are replaced, normal operation can be performed by changing the data in the storage device. Further, since the compressor performs the oil return operation at regular intervals, even if a refrigerant that is conventionally incompatible with the refrigerating machine oil is used, poor lubrication due to insufficient refrigerating machine oil in the compressor does not occur. Further, by changing the set temperature data provided for protecting the compressor, it is possible to prevent the compressor from being overloaded even if refrigerants having different evaporation pressure characteristics are used. Further, in the case of refrigerants having greatly different characteristics, normal operation can be performed by changing the relationship between the compressor rotation speed and the capacity or the data of the compressor rotation speed and the applied voltage.

Although the first storage device and the second storage device are provided by the refrigerant in this embodiment, data of different refrigerants may be stored in one storage device and switched by the storage device changeover switch. . Further, instead of using the changeover switch, a removable storage device such as an IC card is provided on the attached base, and when storing different refrigerants, the storage device storing the data of the sealed refrigerant is installed. Also, the same effect can be obtained.
In this case, the data of the storage device can be changed by the alternative refrigerant to be enclosed, and there is an advantage that it is not necessary to determine a specific alternative refrigerant when manufacturing the air conditioner. Furthermore, during the oil return operation, the expansion valve was fully opened to increase the rotation speed of the compressor, but in a compressor in which the rotation speed of the compressor is fixed, even if the expansion valve is only fully opened, there is an oil recovery effect. .

Another embodiment of the present invention will be described with reference to FIGS. 5, 6 and 7.

FIG. 5 is a control circuit diagram of an air conditioner according to another embodiment of the present invention. FIG. 6 is a refrigeration cycle diagram of an air conditioner according to another embodiment of the present invention. FIG. 7 is a time chart during the oil recovery operation.

In FIG. 5, reference numeral 32 is an oil recovery operation switch provided in the outdoor controller 1.

In FIG. 6, reference numeral 33 is an oil drain valve provided in the lower portion of the hermetic compressor 3 in which an electric portion and a compression element are incorporated and the refrigerating machine oil is enclosed in the lower portion, and 34 is an oil filling valve provided in the upper portion of the compressor.

The operation of the air conditioner configured as above will be described.

During the cooling and heating operations, the same operation as in the above embodiment is performed. The operation when it is necessary to replace the refrigerant will be described with reference to FIG.

When the oil recovery switch 32 is turned on, the compressor 3 is operated at high speed and the expansion valve 9 is fully opened based on the data stored in the first storage device 15. Further, the outdoor fan 7 and the indoor fan 20 are turned on. The four-way valve 5 is on the heating operation side. After the lapse of Δt1 hour, the compressor 3 is rotated at a low speed, and the expansion valve 9 is controlled so that the temperature difference detected by the outdoor heat exchanger temperature detector 11 and the refrigerant suction temperature detector 12 becomes a set value. . Further, when Δt2 hours has elapsed, the compressor and the like stop, and the oil recovery operation ends. Since the compressor 3 is initially operated at a high speed, a large amount of refrigerant circulates in the refrigeration cycle, and even if refrigeration oil remains in the refrigeration cycle, it is recovered in the compressor in a short time. Further, by operating the compressor 3 at a low speed after the high speed operation, the outflow amount of the refrigerating machine oil from the compressor 3 is reduced,
Refrigerating machine oil that flows out together with the refrigerant during high-speed operation of the compressor is also dissolved in the refrigerant and returns to the compressor. Therefore, most of the refrigerating machine oil flowing out into the refrigerating cycle is recovered by the compressor. In this state, the service valve 27, the refrigerant, the oil drain valve 3
3, the refrigerating machine oil is collected, the service valve 27 is evacuated, and the oil sealing valve 34 is used as a refrigerating machine oil for the alternative refrigerant.
For example, the same operation as that of the embodiment can be performed by enclosing the ester oil and enclosing the alternative refrigerant after the evacuation.

As described above, according to this embodiment, the refrigerating machine oil in the compressor can be replaced with that for the alternative refrigerant. Furthermore, by performing a refrigerating machine oil recovery operation before replacing the refrigerating machine oil, the amount of old refrigerating machine oil can be reduced as much as possible.

In the above embodiment, an air conditioner having one indoor unit for one outdoor unit was used as the refrigeration apparatus, but the present invention has a plurality of units for one outdoor unit. The present invention can be used for all air conditioners having indoor units, or for refrigerating devices such as refrigerators that compress refrigerant.

[0033]

According to the present invention, by providing means for changing the data in the storage device of the refrigerator depending on the refrigerant used, normal control can be performed even when different refrigerants are enclosed.

[Brief description of drawings]

FIG. 1 is a block diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a system diagram of a refrigeration cycle of an air conditioner according to an embodiment of the present invention.

FIG. 3 is a temperature distribution diagram of the outdoor heat exchanger.

FIG. 4 is a time chart during oil return operation.

FIG. 5 is a control circuit diagram of an air conditioner according to another embodiment of the present invention.

FIG. 6 is a system diagram of a refrigeration cycle of an air conditioner according to another embodiment of the present invention.

FIG. 7 is a time chart during an oil recovery operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outdoor controller, 3 ... Compressor, 5 ... 4-way valve, 9 ... Expansion valve, 10 ... Discharge refrigerant temperature detector, 11 ... Outdoor heat exchanger temperature detector, 12 ... Suction refrigerant temperature detector, 14 ... Storage device changeover switch, 15 ... First storage device, 16 ... Second storage device, 17 ... Indoor controller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kensaku Oguni 502 Jinritsucho, Tsuchiura-shi, Ibaraki Prefecture Hiritsu Manufacturing Co., Ltd.Mechanical Research Institute (72) Toshihiko Fukushima 502 Kintate-cho, Tsuchiura-shi, Ibaraki Nitate Manufacturing Co., Ltd. Inside the mechanical laboratory

Claims (1)

[Claims] A compressor, a condenser, an expansion valve, and an evaporator are connected, and the operation is performed based on a detector for detecting the operating condition of each part, a signal from the detector, and data stored in a storage device. A refrigeration apparatus having a controller for performing the refrigeration apparatus, wherein the data in the storage device is changed according to a refrigerant used.