JP2003194446A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator capable of cooling storage chambers having different temperature zones certainly to the specified temperature by stabilizing the operation of a pressure reducing device consisting of a capillary tube and motor-driven expansion valve. <P>SOLUTION: The refrigerator is provided with a refrigerating cycle in which a compressor 1, condenser 2, the pressure reducing device consisting of the capillary tube 3 and motor-driven expansion valve 4, and an evaporator 5 are connected in the sequence as named, the refrigerator body furnished with a plurality of storage chambers having different temperature zones, a blower fan 9 to send the cold air having undergone a heat exchange in the evaporator 5 to the storage chambers 15-18, opening/closing dampers 10 and 11 installed in the blowing passages 23 and 24 which guide the cold air upon branching, and a control device to control the degree of opening of the expansion valve 4 and opening and closing of the dampers 10 and 11, wherein the capillary tube is connected to the refrigerant inlet side of the expansion valve 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator, and more particularly to a refrigerator in which a common evaporator cools a plurality of storage chambers in different temperature zones.

[0002]

2. Description of the Related Art As a conventional refrigerator, Japanese Patent Laid-Open No. 8-
As disclosed in Japanese Patent No. 296942, a refrigeration cycle in which a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe are sequentially connected, In the refrigerator body that forms storage chambers of different temperature zones, a blower fan that blows cool air that has undergone heat exchange in the evaporator to each storage chamber, and each air duct that branches and guides the cool air from the blower fan to each storage chamber. Equipped with an opening / closing damper provided and a control device that controls the opening of the electric expansion valve and the opening / closing of the opening / closing damper corresponding to the storage room to be cooled, and the electric expansion valve is connected to the refrigerant inlet side of the capillary tube. There is something I did.

[0003]

However, in the related art, since the electric expansion valve is connected to the refrigerant inlet side of the capillary tube, when the refrigerant is supercooled in the condenser of the refrigeration cycle, The liquid refrigerant will flow into the electric expansion valve. As a result, the decompression operation of the electric expansion valve becomes unstable, and it is difficult to reliably cool the storage chambers in different temperature zones to a predetermined temperature.

Further, the prior art does not describe the use of a low temperature suction pipe to improve the efficiency of the refrigeration cycle. Even if the suction pipe is thermally connected to the conventional capillary tube, the refrigerant whose pressure is reduced by the electric expansion valve and whose temperature is lowered flows through the capillary tube, so that the heat generated between the capillary tube and the suction pipe is reduced. The exchange amount is extremely small, and the efficiency of the refrigeration cycle cannot be sufficiently increased.

Further, the prior art describes that the opening degree of the electric expansion valve is forcibly controlled when shifting from the cooling operation of the storage chamber in the low temperature zone to the cooling operation of the storage chamber in the high temperature zone. It has not been. In the conventional refrigerator, when the cooling operation of the storage room in the low temperature zone is changed to the cooling operation of the storage room in the high temperature zone, the opening / closing damper of the air passage to the low temperature zone is closed to blow air to the high temperature zone. When the passage opening / closing damper is opened, there is a problem that the temperature of the air ventilated to the evaporator rises sharply, a shortage of refrigerant in the evaporator occurs, and the efficiency of the refrigeration cycle decreases.

A first object of the present invention is to provide a refrigerator capable of stabilizing the decompression operation of the decompression device and reliably cooling the storage chambers in different temperature zones to a predetermined temperature.

A second object of the present invention is to provide a refrigerator capable of stabilizing the decompression operation of the decompression device to reliably cool the storage chambers in different temperature zones to a predetermined temperature and improving the efficiency of the refrigeration cycle. It is in.

A third object of the present invention is to provide a refrigerator capable of improving the efficiency of the refrigeration cycle by improving the shortage of refrigerant when shifting from the cooling operation of the storage chamber in the low temperature zone to the cooling operation of the storage chamber in the high temperature zone. To do.

The present invention is not limited to such an object, and objects and advantages other than the above will be apparent from the following description.

[0010]

In order to achieve the first object, the present invention provides a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, And a refrigeration cycle in which suction pipes are sequentially connected, a refrigerator body having a plurality of storage chambers in different temperature zones, a blower fan that blows cool air that has undergone heat exchange in the evaporator to the storage chambers, and the blower fan From the opening / closing damper provided in each air passage for branching and guiding the cool air to the respective storage chambers, and controlling the opening degree of the electric expansion valve and the opening / closing of the opening / closing damper corresponding to the storage chamber to be cooled. In a refrigerator provided with a control device, the capillary tube is connected to a refrigerant inlet side of the electric expansion valve.

In order to achieve the second object, the present invention sequentially connects a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe. Refrigeration cycle, a refrigerator body having a plurality of storage compartments in different temperature zones, a blower fan for blowing the cold air heat-exchanged by the evaporator to the storage compartments, and the blower fan to the storage compartments. An opening / closing damper provided in each air passage for branching and guiding the cool air, and a control device for controlling the opening degree of the electric expansion valve and the opening / closing of the opening / closing damper corresponding to the storage chamber to be cooled. In the refrigerator, the capillary tube is provided so as to be connected to the refrigerant inlet side of the electric expansion valve and to be in thermal contact with the suction pipe in the longitudinal direction.

In order to achieve the third object, according to the present invention, a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe are sequentially connected. Refrigeration cycle, a refrigerator body having a plurality of storage compartments in different temperature zones, a blower fan for blowing the cold air heat-exchanged by the evaporator to the storage compartments, and the blower fan to the storage compartments. An opening / closing damper provided in each air passage for branching and guiding the cool air, and a control device for controlling the opening degree of the electric expansion valve and the opening / closing of the opening / closing damper corresponding to the storage chamber to be cooled. In the refrigerator, the control device forcibly controls the opening degree of the electric expansion valve to a large opening degree when shifting from the cooling operation of the storage room in the low temperature zone to the cooling operation of the storage room in the high temperature zone. After that, Those having a function of controlling at the opening to respond.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

First, the structure of the refrigerating cycle of this embodiment will be described with reference to FIG.

The refrigeration cycle shown in FIG. 1 comprises a compressor 1, a discharge pipe 22, a condenser 2, a capillary tube 3, an electric expansion valve 4, an evaporator 5 and a suction pipe 6 which are sequentially connected. The capillary tube 3 and the electric expansion valve 4 form a pressure reducing device.

The compressor 1 is capable of controlling the number of revolutions by a control device 21, and is constructed so that a low temperature low pressure refrigerant gas is sucked from a suction pipe 6 and discharged as a high temperature high pressure refrigerant gas from a discharge pipe 22. . The condenser 2 condenses the high-temperature high-pressure refrigerant gas discharged from the compressor 1 by radiating heat.

The capillary tube 3 is for decompressing the refrigerant, and has a large inner diameter (in this embodiment, an inner diameter of 1 mm or more) and a predetermined length. The capillary tube 3 is connected in series to the refrigerant inlet side of the electric expansion valve 4, and is installed so as to make thermal contact with the suction pipe 6 in the longitudinal direction by thermal contact with a counterflow.

The electric expansion valve 4 is for decompressing the refrigerant, and is connected in series to the refrigerant outlet side of the capillary tube 3. The electrically-operated expansion valve 4 is adapted to adjust the pressure reduction amount in addition to the pressure reduction of the capillary tube 3, and the opening degree thereof can be controlled by the control device 21.

The evaporator 5 evaporates the depressurized refrigerant and absorbs heat from the surroundings, and exchanges heat with the air in the refrigerator blown by the blower fan 9 to cool the inside of the refrigerator.

The temperature sensor 7 detects the temperature on the inlet side of the evaporator 5, and the temperature sensor 8 detects the temperature of the suction pipe. Detection signals of the temperature sensors 7 and 8 are input to the control device 21.

The control device 21 is for cooling the compressor 1, the electric expansion valve 4, the blowing fans 9 and 11, the blowing fan 9 and the condenser based on the detection signals from various sensors and the input signals from the input device. It is configured to control the fan 26 and the like.

Next, the entire construction of the refrigerator of this embodiment is shown in FIG.
Will be described with reference to.

The refrigerator main body 30 is formed of an outer box, an inner box, and a heat insulating material filled between them. The refrigerator main body 30 forms a plurality of storage rooms that can store and store articles. These storage rooms are, from the top, a refrigerator room 15, a vegetable room 16, an upper freezing room 17, and a lower freezing room 18.
It is composed of. The vegetable compartment 16 and the freezer compartment 17 are partitioned by a heat insulating partition wall 35 having a heat insulating material in order to reduce heat transfer between the two compartments. Doors 31 to 3 for opening and closing the storage chambers are provided on the front side of the storage chambers 15 to 18.
4 are provided.

The refrigerating compartment 15, the vegetable compartment 16 and the freezing compartments 17, 18 are cooled so as to form a storage compartment in a different temperature zone.
It is cooled as a storage room in a temperature zone extremely lower than 6.

The evaporator 5 and the blower fan 9 are arranged behind the vegetable compartment 16 and the freezer compartment 17, and the evaporator 5 is arranged on the lower suction side of the blower fan 9. A blower passage 25 on the suction side is formed below the evaporator 5, and the blower passage 25 communicates with the suction side of the blower fan 9 through the evaporator 5.
The blower fan 9 is configured to be controllable in rotation speed by the control device 21.

A blower duct 23 is formed from the discharge side of the blower fan 9 into a blower duct 23 communicating with the refrigerating compartment 15 and a blower duct 24 communicating with the freezer compartments 17, 18. Opening / closing dampers 10 and 11 are independently arranged in the air passages 23 and 24, respectively. The opening / closing dampers 10 and 11 are configured such that the opening / closing operation is independently controlled by the control device 21. In addition, the storage chambers 15-18 of a plurality of temperature zones
When cooling at the same time, the storage chamber 1 of the plurality of temperature zones
Opening / closing dampers 10 and 11 for air passages 23 and 24 to 5 to 18
Are controlled to open simultaneously.

After the cool air cooled by the evaporator 5 is blown out from the blower duct 23 into the refrigerating compartment 15 as shown by the flow 19 of the cool air to cool the refrigerating compartment 15, part of the cool air returns to the blower duct 25 and the remaining Is blown into the vegetable compartment 16 to cool the vegetable compartment 16 and then return to the air duct 25.

Further, the cold air cooled by the evaporator 5 is blown out from the air passage 24 into the freezing compartment 17 and the freezing compartment 18 as shown by the flow 20 of the cold air to cool the freezing compartment 17 and the freezing compartment 18, and then the air is blown. An air blow passage is formed so as to return to the passage 25.

A temperature sensor 12 for detecting the temperature outside the refrigerator is arranged outside the refrigerator, and temperature sensors 13 and 14 for detecting the temperature inside the refrigerator are arranged inside the refrigerator. The temperature sensor 12 is installed in front of the refrigerator compartment door 31. The temperature sensor 13 is installed in the refrigerator compartment 15, and the temperature sensor 14 is installed in the vegetable compartment 16. Detection signals of the temperature sensors 12 to 14 are input to the control device 21.

A machine room is formed in the lower corner of the back of the refrigerator body 30, and the compressor 1, the condenser 2 and the condenser cooling fan 26 are arranged in the machine room. The compressor 1 and the condenser cooling fan 26 are configured to be controlled by the controller 21.

Next, the operating states of the refrigerating compartment cooling operation and the refrigerating compartment cooling operation of the above refrigeration cycle will be described with reference to the pressure-enthalpy diagram shown in FIG.

FIG. 3 shows the operation of the present embodiment on the Mollier diagram in which the horizontal axis shows the enthalpy i (that is, the absorption and release of heat due to changes in the state of the refrigerant) and the vertical axis shows the evaporation pressure P of the refrigerant. It is a thing. S is a saturated vapor line, SL to the left of E,
If the right side is SG, the region surrounded by the saturated vapor lines SL and SG is in a gas-liquid mixed state, the left side of the saturated vapor line SL is in the liquid state, and the right side of the saturated vapor line SG is in the gas state.

In FIG. 3, A ₁ BCD ₁ shows the change of the refrigerant in the freezing room cooling operation. A ₁ B indicates compression of the refrigerant gas by the compressor 1. BC indicates the release of heat by the condenser 2, and the refrigerant may change from a gas state to a liquid state through a gas-liquid mixed state, which case is illustrated. CD ₁ is a decompression device (capillary tube 3 and electric expansion valve 4)
2 shows the decompression by and the heat dissipation by the capillary tube 3. This CD ₁ is the pressure reduction and heat radiation CD ₀ by the capillary tube 3 and the pressure reduction D ₀ D ₁ by the electric expansion valve 4.
It consists of D ₁ A ₁ indicates the absorption of heat by the evaporator 5 (in this case, cooling of the freezer) and the absorption of heat by the suction pipe 6, and the refrigerant changes from a gas-liquid mixed state to a gas state.

Further, in FIG. 3, A ₂ BCD ₂ shows the change of the refrigerant in the refrigerating compartment cooling operation. A ₂ B is compressor 1
2 shows compression of refrigerant gas by. BC indicates the release of heat by the condenser 2, and the refrigerant may change from a gas state to a liquid state through a gas-liquid mixed state, which case is illustrated. C
D ₂ indicates decompression by the decompression device (capillary tube 3 and electric expansion valve 4) and heat dissipation by the capillary tube 3. D ₂ A ₂ indicates heat absorption by the evaporator 5 (cooling of the refrigerating chamber in this case) and heat absorption by the suction pipe 6, and the refrigerant is gasified from the gas-liquid mixed state. CD ₂ is composed of CD ₀ indicating the pressure reduction and heat dissipation by the capillary tube 3 and D ₀ D ₂ indicating the pressure reduction by the electric expansion valve 4.

Reduced pressure P from the liquid state of the refrigerant to the gas-liquid mixed state
_{Since the} capillary tube 3 is used for the CD _0, which is ₀ , even if the pressure is reduced from the liquid state, it is possible to stably reduce the pressure by the capillary tube method which is widely used and has a proven record. Since this CD ₀ is common to both the freezing compartment cooling operation and the refrigerating compartment cooling operation, a stable depressurizing operation can be performed in any of these operations. Also,
Both of the pressure reduction P ₁ of the electric expansion valve 4 in the freezing compartment cooling operation and the pressure reduction P ₂ of the electric expansion valve 4 in the refrigerating compartment cooling operation result in the pressure reduction in the gas-liquid mixed state. A stable pressure reducing function can be obtained even by control by the opening degree. Therefore, even if it is supercooled by the condenser 2 and becomes a liquid refrigerant, it is possible to stably reduce the pressure in both the freezing compartment cooling operation and the refrigerating compartment cooling operation. By stabilizing the decompression operation of the decompression device in this manner, the storage chambers 15 to 18 in different temperature zones can be reliably cooled to a predetermined temperature.

Moreover, since this capillary tube 3 has a large inner diameter (specifically, an inner diameter of 1 mm or more), it is possible to obtain a stable pressure reduction from the liquid state to the gas-liquid mixed state. You can

Further, since the capillary tube 3 is provided on the refrigerant inlet side of the electric expansion valve 4 and is a heat exchange in the longitudinal direction at a portion where the temperature difference with the suction pipe 6 is large,
As shown by Δi ₁ in FIG. 3, the efficiency of the refrigeration cycle can be improved.

In FIG. 3, the line vf is the specific volume of the refrigerant when the compressor is sucked in the freezing room cooling operation, and the line vr.
Shows the specific volume of the refrigerant when the compressor is sucked in the refrigerating room cooling operation. Generally, the heat absorption amount Q of the refrigerant is expressed by the following equation (1).

Q = GΔi (1) Where, G: Circulating flow rate of refrigerant (G = V / v · R), Δ
i: enthalpy difference, V: compressor displacement, v: specific volume of refrigerant, R: proportional constant.

As is apparent from FIG. 3, when the refrigerating chamber, which is a cooling chamber having a high temperature zone, is cooled, the evaporating pressure P also rises, and the specific volume v of the refrigerant becomes smaller and v = vr. As a result, the circulation amount of the refrigerant increases. Therefore, it is possible to obtain a larger refrigerating capacity and a coefficient of performance than a conventional refrigerator.
Therefore, it is possible to cool the cooling chamber having a high temperature range with a high coefficient of performance and a short operating time.

Next, the basic control operation of the refrigerator will be described with reference to the flowchart of FIG.

When the operation of the compressor 1 and the blower fan 9 is started by signals from various sensors (step 41),
First, the electric expansion valve 4 is fully opened (step 42). Next, it is determined whether the refrigerating compartment cooling operation is to be performed (step 43). Specifically, this determination is performed by the temperature sensors 13, 14 such as the refrigerator compartment 15 and the freezer compartment 17 installed in the refrigerator.
For example, whether to cool the refrigerating chamber 15 or the freezing chamber 17 is selected.

If it is determined in this determination that the refrigerating compartment cooling operation is not performed, it is determined that the freezing compartment cooling operation is performed, and the opening / closing damper 1
1 is opened and the opening / closing damper 10 is closed (step 44). Then, referring to the compressor rotation speed, the evaporation temperature of the evaporator 5 is set to a temperature in a low temperature zone for cooling the freezer (for example, −).
18 ° C.) (step 45). Electric expansion valve 4
After the valve is fully opened for a predetermined time, the electric expansion valve 4 is sequentially operated stepwise in the closing direction at predetermined times, and thereafter the opening degree of the electric expansion valve 4 is adapted to the freezing compartment cooling operation. The evaporation temperature is detected and controlled until the temperature reaches the set temperature (step 46). In this way, the refrigeration cycle and the blower fan 9 are operated, and it is determined whether or not the freezer compartment temperature has reached the predetermined temperature (step 47). When the freezer compartment temperature has not reached the predetermined temperature, the process returns to step 46 and the following steps are repeated. When the freezer compartment temperature reaches a predetermined temperature, the freezer compartment cooling operation ends.

If it is determined in step 43 that the refrigerator is operating, the opening / closing damper 10 is opened and the opening / closing damper 11 is closed (step 51). Then, the evaporation temperature of the evaporator 5 is set to the temperature in the high temperature zone for cooling the refrigerating compartment with reference to the compressor rotation speed (step 52). After the electric expansion valve 4 is fully opened for a predetermined time, the electric expansion valve 4 is sequentially operated stepwise in the closing direction every predetermined time.
After that, the opening degree of the electric expansion valve 4 is controlled until it reaches the set temperature while detecting the evaporation temperature so as to adapt to the refrigerating chamber cooling operation (step 53). In this way, the refrigeration cycle and the blower fan 9 are operated, and it is determined whether the refrigerating compartment temperature has reached the predetermined temperature (step 54). If the freezer compartment temperature has not reached the predetermined temperature, step 53
And the following steps are repeated. When the refrigerating compartment temperature reaches a predetermined temperature, the refrigerating compartment cooling operation ends.

The flow chart shows a basic operation, and a specific operation example will be described with reference to FIG.

As shown in FIG. 5, when the refrigerating room cooling operation is completed, the electric expansion valve 4 is closed, the compressor 1 is stopped, and the operation of the refrigeration cycle is stopped, but the opening / closing damper 10 is opened. The blower fan 9 is operated to perform the moisturizing operation for a predetermined time. In this moisturizing operation, the water adhering to the surface of the evaporator 5 is evaporated and returned to the inside of the refrigerating compartment 15 to return to the refrigerating compartment
This is the operation to prevent the inside of 5 from drying. Since the electric expansion valve 4 is closed when the refrigeration cycle is stopped, the high-temperature refrigerant on the condenser 2 side flows into the low-temperature evaporator 5 via the electric expansion valve 4 and causes heat loss. Is prevented.

When the refrigerating room cooling operation is started with the refrigerator stopped, the opening / closing damper 10 is opened and
The opening / closing damper 11 is closed and the operation of the compressor 1 is started, but the electric expansion valve 4 is first fully opened for a predetermined time as described above, and the blower fan 9 is operated after a delay of a predetermined time. Be started.

In the refrigerator in which the compressor 1 is repeatedly operated and stopped by increasing the opening degree of the electric expansion valve 4 at the time of starting the compressor as described above, the refrigerant retained in the evaporator 5 is sucked during the stop. Since it can be sent to the condenser 2 side and condensed at an early stage, an appropriate refrigeration cycle state can be achieved in a short time.

This point will be described more specifically. In a refrigerator using only a general capillary tube, the refrigerant in the stopped refrigeration cycle is mainly condensed in the low temperature evaporator 5, and the refrigerant is condensed in the condenser 2 when the compressor 1 is started. In addition, since the capillary tube with a small inner diameter is used, the refrigerant in the condenser 2 is difficult to return to the evaporator 5, and the temperature difference between the inlet temperature and the outlet temperature of the evaporator 5 is large due to the insufficient circulating amount of the refrigerant. A state of low ability occurs. On the other hand, in this embodiment, since the capillary tube 3 having a large inner diameter and the electric expansion valve 4 are connected and used, the opening degree of the electric expansion valve 4 is increased at the time of starting the compressor which causes a shortage of the refrigerant circulation amount. Then, the refrigerant in the condenser 2 can easily flow into the evaporator 4. Then, by operating the opening degree of the electric expansion valve 4 in the closing direction as the temperature of the evaporator 5 decreases, an appropriate refrigeration cycle can be generated in a short time.

Further, as described above, by delaying the start of the operation of the blower fan 9 for a predetermined time, the temperature of the evaporator 4 is lowered to a predetermined temperature, and then the cool air is supplied to the freezing compartment 17, It is possible to prevent warm air from being supplied to the freezer compartment 17.

Note that these predetermined times are not limited to fixed times, and may be predetermined times changed according to other conditions.

When the fully open time of the electric expansion valve 4 has elapsed,
The electric expansion valve 4 is controlled so as to adapt to the refrigerating compartment cooling operation as described above.

When the refrigerating compartment cooling operation is changed to the freezing compartment cooling operation, the electric expansion valve 4, the blower fan 9 and the compressor 1 are moved in the refrigerating compartment cooling operation state and the opening / closing damper 10 is closed. At the same time, the opening / closing damper 11 opens.
Then, the electric expansion valve 4 is controlled to adapt to the freezing room cooling operation after a predetermined time. When the freezing room cooling operation is completed, the electric expansion valve 4, the opening / closing damper 10 and the opening / closing damper 11 are closed and the operation of the blower fan 9 is stopped, but the compressor 1 recovers the refrigerant from the condenser 2 for a predetermined time. The operation to do so is performed. By this refrigerant recovery operation,
It is possible to prevent heat from entering the inside due to the high temperature refrigerant.

When the freezer compartment cooling operation is started with the refrigerator stopped, the opening / closing damper 11 is opened and
The opening / closing damper 10 is closed and the operation of the compressor 1 is started, but the electric expansion valve 4 is first fully opened for a predetermined time as described above, and the blower fan 9 is operated after a delay of a predetermined time. Be started. Here, the reason why the electric expansion valve 4 is first fully opened for a predetermined time and the operation start of the blower fan 9 is delayed for a predetermined time is the same as the reason described in the refrigerating compartment cooling operation described above.

When the freezing room cooling operation is changed to the refrigerating room cooling operation, the blower fan 9 and the compressor 1 are changed to the refrigerating room cooling operation state, the opening / closing damper 10 is closed, and the opening / closing damper 11 is opened. Open, but electric expansion valve 4
Is operated fully open for a predetermined time. When switching from the freezing compartment cooling operation to the refrigerating compartment cooling operation, the evaporator 4
The temperature of the inflowing air into the system suddenly rises and evaporation is promoted, and the refrigerant in the evaporator 4 runs short.
By forcibly increasing the opening degree of the refrigerant, the refrigerant in the condenser 2 can be easily returned to the evaporator 4, and the proper cycle state can be achieved early. Thereby, the efficiency of the refrigeration cycle can be improved.

The electric expansion valve 4 is fully opened for a predetermined time, and then controlled so as to be adapted to the refrigerating compartment cooling operation.

When shifting from the refrigerating room cooling operation to the defrosting operation, the electric expansion valve 4 is fully opened, the blower fan 9 and the compressor 1 are stopped, and the opening / closing damper 10 and the opening / closing damper 11 are closed. Then, the defrost heater (not shown) is energized. Thereby, the frost adhering to the evaporator 5 is regularly removed. At the end of the defrosting operation, the blower fan 9 and the compressor 1 are operated for a predetermined time to collect the refrigerant.

When the temperature detected by the temperature sensor 8 attached to the suction pipe 6 of the compressor 1 is lower than a predetermined temperature, the opening degree of the electric expansion valve 4 is operated in the opening direction.
The temperature of the suction pipe 6 is raised to prevent dew condensation. On the contrary, when the temperature of the suction pipe 6 is equal to or higher than the predetermined temperature due to lack of refrigerant or high-speed operation of the compressor, the opening of the electric expansion valve 4 is operated in the closing direction to return the low temperature refrigerant to the compressor 1. The temperature rise of the compressor 1 is prevented.

Further, when the refrigerating room 15 and the freezing room 17 are operated from a high temperature state or the ambient temperature is high and the cooling load increases due to a temporary large amount of food, such as when the refrigerator is installed, the refrigerating room 15 and By opening both dampers 10 and 11 to the freezing compartment 17 and simultaneously increasing the expansion valve opening, the cooling capacity can be maximized.

[0060]

As is apparent from the above description, according to the present invention, it is possible to obtain a refrigerator capable of stabilizing the depressurizing operation of the depressurizing device and reliably cooling the storage chambers in different temperature zones to predetermined temperatures.

Further, according to the present invention, it is possible to obtain a refrigerator in which the decompression operation of the decompression device can be stabilized and the storage chambers in different temperature zones can be reliably cooled to a predetermined temperature and the efficiency of the refrigeration cycle can be improved.

Further, according to the present invention, it is possible to obtain a refrigerator capable of improving the efficiency of the refrigeration cycle by improving the shortage of the refrigerant when shifting from the cooling operation of the storage chamber in the low temperature zone to the cooling operation of the storage chamber in the high temperature zone. .

[Brief description of drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle of a refrigerator according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the refrigerator.

FIG. 3 is a pressure-enthalpy diagram of the refrigeration cycle of FIG.

FIG. 4 is a flowchart showing a basic operation example of the refrigerator shown in FIG.

5 is a time chart diagram showing an operation example of the refrigerator shown in FIG. 2. FIG.

[Explanation of symbols]

1 ... Compressor, 2 ... Condenser, 3 ... Capillary tube, 4
... Electric expansion valve, 5 ... Evaporator, 6 ... Suction pipe, 7, 8 ...
Temperature sensor, 9 ... Blower fan, 10, 11 ... Open / close damper, 12, 13, 14 ... Temperature sensor, 15 ... Refrigerator, 1
6 ... Vegetable room, 17, 18 ... Freezer room, 19, 20 ... Cold air flow, 21 ... Control device, 22 ... Discharge piping, 23, 24,
25 ... Blower, 26 ... Condenser cooling fan, 30 ... Refrigerator body, 31 ... Refrigerator compartment door, 32 ... Vegetable compartment door, 33, 34
… Freezer door, 35… Insulation partition wall.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akiyoshi Ohira             502 Kintatemachi, Tsuchiura City, Ibaraki Japan             Tate Seisakusho Mechanical Research Center F term (reference) 3L045 AA01 AA06 DA02 EA01 HA01                       JA13 LA05 MA04 NA07 NA22                       PA02 PA03 PA04 PA05

Claims (7)

[Claims] 1. A refrigeration cycle in which a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe are sequentially connected, and a storage chamber in a plurality of different temperature zones. A refrigerator main body that forms a fan, a blower fan that blows cool air that has undergone heat exchange in the evaporator to each of the storage chambers, and a blower path that branches and guides the cool air from the blower fan to each of the storage chambers. A refrigerator provided with an opening / closing damper and a control device for controlling the opening degree of the electric expansion valve and opening / closing of the opening / closing damper corresponding to a storage room to be cooled, wherein the capillary tube is the electric expansion valve. A refrigerator characterized by being connected to the refrigerant inlet side of. 2. A refrigeration cycle in which a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe are sequentially connected, and a storage chamber in a plurality of different temperature zones. A refrigerator main body that forms a fan, a blower fan that blows cool air that has undergone heat exchange in the evaporator to each of the storage chambers, and a blower path that branches and guides the cool air from the blower fan to each of the storage chambers. A refrigerator provided with an opening / closing damper and a control device for controlling the opening degree of the electric expansion valve and opening / closing of the opening / closing damper corresponding to a storage room to be cooled, wherein the capillary tube is the electric expansion unit. A refrigerator which is connected to the refrigerant inlet side of the valve and is provided in thermal contact with the suction pipe in the longitudinal direction. 3. The control device according to claim 1, wherein the control device increases the opening degree of the electrically driven expansion valve when cooling the storage chamber in a high temperature zone independently, and blows air to the storage chamber. While opening the opening and closing damper of the passage and closing the opening and closing damper of the air passage to the other storage chamber, while cooling the storage chamber in the low temperature zone independently, while reducing the opening degree of the electric expansion valve, When the opening / closing damper of the air passage to the storage room is opened and the opening / closing damper of the air passage to another storage room is closed, and when the storage rooms of the plurality of temperature zones are simultaneously cooled, A refrigerator having a function of controlling to open and close a damper for opening and closing a ventilation path to a storage room. 4. The refrigerator according to claim 1 or 2, wherein the capillary tube has an inner diameter of 1 mm or more. 5. A refrigeration cycle in which a compressor, a discharge pipe, a condenser, a pressure reducing device composed of a capillary tube and an electric expansion valve, an evaporator, and a suction pipe are sequentially connected, and a storage chamber in a plurality of different temperature zones. A refrigerator main body that forms a fan, a blower fan that blows cool air that has undergone heat exchange in the evaporator to each of the storage chambers, and a blower path that branches and guides the cool air from the blower fan to each of the storage chambers. In a refrigerator provided with an opening / closing damper and a control device that controls the opening degree of the electric expansion valve and the opening / closing of the opening / closing damper in correspondence with a storage room to be cooled, the control device is When shifting from the cooling operation of the storage room to the cooling operation of the storage room in the high temperature zone, after forcibly controlling the opening degree of the electric expansion valve to a large opening degree, the opening degree corresponding to the temperature zone is controlled. The ability to Refrigerator and features. 6. The control device according to claim 5, wherein, when shifting from a cooling operation of the storage chamber in the high temperature zone to a cooling operation of the storage chamber in the low temperature zone, the control device controls the opening degree of the electric expansion valve. A refrigerator having a function of controlling to adapt to the temperature range by reducing the opening degree in multiple stages after forcibly controlling to fully open. 7. The refrigerator according to claim 5, wherein the electric expansion valve is connected to a refrigerant outlet side of the capillary tube, and the capillary tube is provided in thermal contact with the suction pipe.