JP2003148846A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constitution of an evaporator which reduces the excess refrigerant retained in an accumulator part of the evaporator and improves the safety in leakage of the refrigerant, in a refrigerator using the combustible refrigerant. SOLUTION: This refrigerator 1 using the combustible refrigerant comprises an evaporator 18, an outlet pipe 18d mounted across an air trunk of the evaporator 18, and an accumulator 18e connected to the outlet pipe 18d and storing the liquid refrigerant. As a result, temperature of the outlet pipe 18d is kept higher than evaporation temperature with the proper amount of refrigerant, the residual refrigerant retained in the accumulator 18e is reduced, and further the accumulator 18e is miniaturized, which reduces the input of a defrosting heater, and improves the safety in leakage of the refrigerant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator using a flammable refrigerant.

[0002]

2. Description of the Related Art Conventionally, an accumulator for storing excess liquid refrigerant is installed at the outlet of an evaporator that cools a refrigerating room or a freezing room of a refrigerator. The purpose is to prevent excess liquid refrigerant from entering the compressor through the suction pipe by storing excess liquid refrigerant in the accumulator. Regarding the function and structure of such an accumulator, there is JP-A-2000-234842.

The conventional refrigerator will be described below with reference to the drawings. FIG. 8 is a longitudinal sectional view of a main part of a conventional refrigerator, and FIG. 9 is a configuration diagram of an evaporator of the conventional refrigerator. 1 is a refrigerator main body, 2 is a freezer compartment inside the refrigerator main body 1, 3
Is a refrigerator compartment inside the refrigerator body 1, 4 is a freezer compartment door, 5
Is a refrigerating compartment door, 6 is a partition wall for partitioning the refrigerating compartment 2 from the refrigerating compartment 3, 7 is a freezing compartment suction port for sucking air in the freezing compartment 2,
Reference numeral 8 is a refrigerating compartment inlet for sucking air in the refrigerating compartment 3, 9 is an outlet for ejecting cool air, 10 is an evaporator, 11 is a blower fan for circulating the cool air, 12 is an evaporator for partitioning the evaporator 10 and the freezer compartment 2. A partition wall, 13 is a trough, 14 is a drain port, 15 is a defrost heater in which a coiled nichrome wire is covered with a glass tube, and 16 is defrost water directly dropped on the defrost heater 15. A cover 17 is provided to prevent evaporation noise generated upon contact, and a metal heat-resistant plate 17 is provided between the vat 13 and the defrosting heater 15. Here, the evaporator 10 includes a straight pipe portion 10 a and a corner portion 10 b that serve as a refrigerant flow path, a cooling fin 10 c that performs heat exchange with the air in the refrigerator 1, and an excess side installed on the outlet side of the evaporator 10. It is composed of an accumulator 10d that stores a liquid refrigerant.

Next, the operation will be described. When cooling the freezer compartment 2 or the refrigerating compartment 3, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is decompressed by the expansion mechanism (not shown). After that, the gas flows to the evaporator 10 and the evaporator 10 is cooled. Similarly, by operating the blower fan 11, the indoor air in the freezer compartment 2 or the refrigerator compartment 3 is sent to the evaporator 10 from the freezer compartment inlet 7 or the refrigerator compartment inlet 8 and heat is exchanged in the evaporator 10. The cooled air is sent from the discharge port 9 to the freezer compartment 2. In addition, freezer room 2
The air inside is sent to the refrigerator compartment 3 through a communication port (not shown). Here, the air that exchanges heat with the evaporator 10 is highly humidified by the inflow of outside air due to the opening and closing of the freezing compartment door 4 and the refrigerating compartment door 5 and the evaporation of water in the stored food in the freezing compartment 2 and the refrigerating compartment 3. Since it is fresh air, frost forms on the surface of the evaporator 10. At this time, the evaporation capacity of the evaporator 10 decreases, and the excess liquid refrigerant that could not be evaporated remains in the accumulator 10d, and the evaporated gas refrigerant passes through a suction pipe (not shown), and a compressor (not shown). ).

[0005]

However, in the above-mentioned conventional configuration, the air passage is designed so that the indoor air in the freezing compartment 2 and the refrigerating compartment 3 and the cooling fins 10c appropriately exchange heat, so that the air is provided outside the air passage. The corner portion 10b and the accumulator 10d are less likely to be heat-exchanged, and have a lower temperature than the straight pipe portion 10a. Therefore, even when the minimum amount of the refrigerant that makes the straight pipe portion 10a substantially uniform is filled, a certain amount of the refrigerant remains in the accumulator 10d. In other words, the conventional configuration requires a slightly excessive amount of refrigerant and an accumulator having a large capacity by the excess amount.

As a result, particularly in a refrigerator using a flammable refrigerant, an increase in the amount of refrigerant enclosed and an increase in the heater input for raising the temperature of the accumulator section during defrosting can cause a risk of refrigerant leakage. It had the drawback of increasing sex.

The present invention solves the conventional problems, and an object of the present invention is to improve the safety at the time of refrigerant leakage by reducing the amount of refrigerant enclosed and reducing the input of the defrosting heater.

[0008]

According to a first aspect of the present invention, in a refrigerator using a flammable refrigerant, an evaporator and the evaporator installed so as to cross an air passage of the evaporator. Of the outlet pipe of the, and the accumulator connected to the outlet pipe, which stores the liquid refrigerant, so that the liquid refrigerant is sufficiently evaporated in the outlet pipe, the accumulator portion is a temperature lower than the evaporator fin portion. As a result, it is possible to improve the safety at the time of refrigerant leakage by reducing the appropriate amount of the refrigerant and reducing the input of the defrosting heater.

According to a second aspect of the present invention, in a refrigerator using a flammable refrigerant, an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, and Since it is equipped with a suction pipe that is connected to the outlet pipe and recirculates the gas refrigerant, it prevents the evaporator outlet from reaching a temperature lower than that of the fins of the evaporator, and also provides an accumulator that does not easily heat up during defrosting. Since it is eliminated, the amount of the refrigerant can be reduced, the input of the defrosting heater can be further reduced, and the safety at the time of refrigerant leakage can be improved.

According to a third aspect of the present invention, in the first or second aspect of the invention, a blower fan for sending air from the evaporator to the inside of the refrigerator and the air passage of the evaporator are crossed. An outlet pipe of the evaporator that is installed, and a detection unit that detects that a liquid refrigerant has entered the outlet pipe, and a control unit that increases the number of rotations of the blower fan when the liquid refrigerant has been detected. Since the above is used, it is possible to cope with a change in the operating state by adjusting the capacity of the evaporator, it is possible to reduce the amount of surplus refrigerant, and it is possible to further reduce the accumulator capacity. At the same time, since the input of the defrosting heater can be reduced by reducing the amount of the refrigerant, the safety at the time of refrigerant leakage can be improved.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, a condenser, a cooling fan for cooling the condenser, an evaporator, and An outlet pipe of the evaporator installed so as to cross the air passage of the evaporator, and a detection means for detecting that the liquid refrigerant has entered the outlet pipe, the cooling is performed when the liquid refrigerant has been detected. Since the control means that increases the fan speed is used, even if the evaporator is frosted, the capacity of the condenser can be adjusted to reduce the amount of excess refrigerant generated due to changes in the operating state, and the accumulator capacity Can be further reduced. At the same time, by reducing the proper amount of refrigerant, the input of the defrosting heater can be reduced, and the safety at the time of refrigerant leakage can be improved.

According to a fifth aspect of the present invention, in the invention according to the third or fourth aspect, the inside temperature sensor installed in the refrigerator, the evaporator, and the air passage of the evaporator are provided. An outlet pipe of the evaporator installed so as to cross,
Equipped with an evaporator temperature sensor installed in the outlet pipe, using a control means for detecting that the liquid refrigerant has entered from the temperature difference between the internal temperature sensor and the evaporator temperature sensor, the excess refrigerant The occurrence of can be detected more easily.

According to a sixth aspect of the present invention, in the invention according to the first aspect, an accumulator is installed in the air passage of the evaporator, and the surplus refrigerant in the accumulator is used for heat exchange. It is possible to surely evaporate in the air passage of a large evaporator and prevent liquid back to the compressor.

According to a seventh aspect of the present invention, in the invention according to the first or sixth aspect, the outlet pipe and the accumulator are molded from a seamless single pipe, and the welded portion of the accumulator and the pipe is formed. Can be eliminated, and the chance of leakage of flammable refrigerant can be reduced.

The invention according to claim 8 of the present invention is the invention according to any one of claims 1 to 7,
The pipes that make up the evaporator are formed by bending one pipe, and the welded part of the entire evaporator can be eliminated.
The chance of leakage of flammable refrigerant can be greatly reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Embodiment 1 of the present invention will be described with reference to the drawings. The same components as those in the conventional example are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a block diagram of a refrigerator according to Embodiment 1 of the present invention, and FIG. 2 is a block diagram of an evaporator of a refrigerator according to Embodiment 1 of the present invention.

1 and 2, 18 is an evaporator of a refrigerator according to the first embodiment of the present invention, and 18a is an evaporator 1
8 straight pipe portion, 18b is a corner portion of the evaporator 18, 18c
Is a fin portion of the evaporator 18, 18d is an outlet pipe of the evaporator 18, and 18e is an accumulator of the evaporator 18. A flammable hydrocarbon refrigerant R600a is used as the refrigerant.

Regarding the refrigerator constructed as described above,
The operation will be described below.

When the freezer compartment 2 or the refrigerating compartment 3 is cooled, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is expanded by the expansion mechanism (not shown). After being decompressed by), the evaporator 18 is cooled by flowing through the straight pipe portion 18a and the corner portion 18b of the evaporator 18. Similarly, the operation of the blower fan 11 causes the freezer inlet 7
The indoor air of the freezer compartment 2 or the refrigerator compartment 3 is sent to the evaporator 18 from the refrigerator compartment intake port 8 or the fin section 1 of the evaporator 18
Air cooled by heat exchange at 8c is sent from the discharge port 9 to the freezer compartment 2. Further, the air in the freezer compartment 2 is sent to the refrigerating compartment 3 through a communication port (not shown). Here, normally, all the liquid refrigerant is vaporized before the outlet pipe 18d of the evaporator 18, and only the gas refrigerant is vaporized in the outlet pipe 18d and the accumulator 18d.
Return to compressor (not shown) through e. At this time,
Since the outlet pipe 18d is separated from the fin portion 18c having a heat transfer function and is installed in the air passage of the evaporator 18, the outlet pipe 18d is maintained at a temperature of several degrees higher than the straight pipe portion 18a and the corner portion 18b. It As a result, the liquid refrigerant does not stay in the accumulator 18e during normal operation.

The air that exchanges heat with the evaporator 18 is highly humid due to the inflow of outside air due to the opening and closing of the freezer compartment door 4 and the refrigerator compartment door 5 and the evaporation of the moisture of the stored food in the freezer compartment 2 and the refrigerator compartment 3. Since it is the converted air, frost forms on the surface of the evaporator 18. At this time, the evaporation capacity of the evaporator 18 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 18d, and a part of the liquid refrigerant remains in the accumulator 18e. Further, the vaporized gas refrigerant flows back to the compressor (not shown) through the suction pipe (not shown).

As described above, it is possible to prevent liquid refrigerant from staying in the accumulator during normal operation by installing the outlet pipe of the evaporator separately from the fin portion and installing it in the air passage. By reducing the amount of unnecessary refrigerant, the safety at the time of refrigerant leakage can be improved. Further, the accumulator can be downsized by the amount by reducing the excessive amount of refrigerant, and the heater capacity during defrosting can be reduced by the amount by which the evaporator is downsized, thereby further improving the safety at the time of refrigerant leakage. be able to.

In this embodiment, in a normal state, all the refrigerant is vaporized before the outlet pipe 18d of the evaporator 18 and only the gas refrigerant is discharged from the outlet pipe 18d and the accumulator 1.
It was supposed to flow back to the compressor (not shown) through 8e,
By using the evaporator 18 having a high evaporation ability, the evaporation of the refrigerant may be promoted and a part of the straight pipe portion 18a or the corner portion 18b may be used as a passage for the gas refrigerant similarly to the outlet pipe 18d. In this case, when the frost formation progresses, the liquid refrigerant enters a portion of the straight pipe portion 18a that was the passage of the gas refrigerant to maintain the evaporation ability, so that the excess refrigerant accumulated in the accumulator 18e can be further reduced. it can.

(Second Embodiment) A second embodiment of the present invention will be described with reference to the drawings. The same components and operations as those in the first embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 3 is a block diagram of a refrigerator according to Embodiment 2 of the present invention, and FIG. 4 is a block diagram of an evaporator of a refrigerator according to Embodiment 2 of the present invention.

3 and 4, 19 is an evaporator of a refrigerator according to the second embodiment of the present invention, and 19a is an evaporator 1
9 straight pipe portion, 19b is a corner portion of the evaporator 19, 19c
Is a fin portion of the evaporator 19, 19d is an outlet pipe of the evaporator 19, and 20 is a suction pipe. A flammable hydrocarbon refrigerant R600a is used as the refrigerant.

Regarding the refrigerator constructed as described above,
The operation will be described below.

When the freezer compartment 2 or the refrigerating compartment 3 is cooled, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is expanded by the expansion mechanism (not shown). After being decompressed by), the evaporator 19 is cooled by flowing through the straight pipe portion 19a and the corner portion 19b of the evaporator 19. Similarly, the operation of the blower fan 11 causes the freezer inlet 7
The indoor air of the freezer compartment 2 and the refrigerator compartment 3 is sent to the evaporator 19 from the refrigerator compartment suction port 8 and the fin portion 1 of the evaporator 19 is supplied.
Air cooled by heat exchange in 9c is sent from the discharge port 9 to the freezer compartment 2. Further, the air in the freezer compartment 2 is sent to the refrigerating compartment 3 through a communication port (not shown). Here, normally, all of the liquid refrigerant is vaporized before the outlet pipe 19d of the evaporator 19, and only the gas refrigerant flows back to the compressor (not shown) through the outlet pipe 19d and the suction pipe 20. At this time, the outlet pipe 19
Since d is separated from the fin portion 19c having a heat transfer function and is installed in the air passage of the evaporator 19,
The temperature is maintained at a temperature higher by several degrees Celsius than that of the straight pipe portion 19a and the corner portion 19b. As a result, the liquid refrigerant does not enter the suction pipe 20 during normal operation.

The air that exchanges heat with the evaporator 19 is highly humid due to the inflow of outside air due to the opening and closing of the freezer compartment door 4 and the refrigerator compartment door 5 and the evaporation of the moisture of the stored food in the freezer compartment 2 and the refrigerator compartment 3. Since it is the converted air, the surface of the evaporator 19 is frosted. At this time, the evaporation capacity of the evaporator 19 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 19d, and a part of the liquid refrigerant is evaporated together with the suction pipe 2
It recirculates through 0 to a compressor (not shown). Here, by exchanging heat between the suction pipe 20 and an expansion mechanism (not shown) including a capillary, it is possible to recover part of the cooling waste heat and evaporate the liquid refrigerant that has entered the suction pipe 20.

As described above, the outlet pipe of the evaporator is separated from the fin portion and installed in the air passage, so that the liquid refrigerant flows back to the compressor (not shown) through the suction pipe 20 during normal operation. Can be prevented, and the accumulator that retains the excess liquid refrigerant can be eliminated. As a result,
By reducing the amount of refrigerant, it is possible to improve the safety at the time of refrigerant leakage, and by reducing the heater capacity during defrosting by reducing the evaporator size by eliminating the accumulator, it is possible to reduce the The safety can be further improved.

In this embodiment, normally, all the refrigerant is vaporized before the outlet pipe 19d of the evaporator 19 and only the gas refrigerant passes through the outlet pipe 19d and the suction pipe 20 and a compressor (not shown). ), But the evaporation of the refrigerant is promoted by using the evaporator 19 having a high evaporation capacity, and a part of the straight pipe portion 19a or the corner portion 19b is used as a passage for the gas refrigerant like the outlet pipe 19d. Good. in this case,
The straight pipe portion 19a that was a passage for the gas refrigerant when frost formed
Since the liquid refrigerant enters a part of the above to maintain the evaporation ability, it is possible to reduce the amount of the liquid refrigerant flowing back to the compressor (not shown) through the suction pipe 20.

(Third Embodiment) A third embodiment of the present invention will be described with reference to the drawings. The same configurations and operations as those of the second embodiment of the present invention are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 5 is a block diagram of an evaporator of a refrigerator according to the third embodiment of the present invention.

In FIG. 5, 19 is an evaporator of a refrigerator according to the third embodiment of the present invention, 19a is a straight pipe part of the evaporator 19, 19b is a corner part of the evaporator 19, 19c is a fin part of the evaporator 19, 19d is an outlet pipe of the evaporator 19, 20
Is an inlet pipe, 21 is an inlet temperature sensor for measuring the evaporation temperature of the refrigerant in the evaporator 19, and 22 is an outlet temperature sensor for measuring the temperature of the outlet pipe 19d. A flammable hydrocarbon refrigerant R600a is used as the refrigerant.

Regarding the refrigerator configured as described above,
The operation will be described below.

When the freezer compartment 2 and the refrigerating compartment 3 are cooled, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is expanded by the expansion mechanism (not shown). After being decompressed by), the evaporator 19 is cooled by flowing through the straight pipe portion 19a and the corner portion 19b of the evaporator 19. Similarly, the operation of the blower fan 11 causes the freezer inlet 7
The indoor air of the freezer compartment 2 and the refrigerator compartment 3 is sent to the evaporator 19 from the refrigerator compartment suction port 8 and the fin portion 1 of the evaporator 19 is supplied.
Air cooled by heat exchange in 9c is sent from the discharge port 9 to the freezer compartment 2. Further, the air in the freezer compartment 2 is sent to the refrigerating compartment 3 through a communication port (not shown). Here, normally, all of the liquid refrigerant is vaporized before the outlet pipe 19d of the evaporator 19, and only the gas refrigerant flows back to the compressor (not shown) through the outlet pipe 19d and the suction pipe 20. At this time, the outlet pipe 19
Since d is separated from the fin portion 19c having a heat transfer function and is installed in the air passage of the evaporator 19,
The temperature is maintained at a temperature higher by several degrees Celsius than that of the straight pipe portion 19a and the corner portion 19b. As a result, the liquid refrigerant does not enter the suction pipe 20 during normal operation. In this case, the outlet temperature sensor 2
The temperature indicated by 2 is maintained at several degrees higher than the temperature indicated by the inlet temperature sensor 21.

The air that exchanges heat with the evaporator 19 is highly humid due to the inflow of outside air due to the opening and closing of the freezer compartment door 4 and the refrigerator compartment door 5 and the evaporation of the moisture of the stored food in the freezer compartment 2 and the refrigerator compartment 3. Since it is the converted air, the surface of the evaporator 19 is frosted. At this time, the evaporation capacity of the evaporator 19 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 19d, and a part of the liquid refrigerant is evaporated together with the suction pipe 2
It recirculates through 0 to a compressor (not shown). In this case, the temperature indicated by the outlet temperature sensor 22 is almost the same as the temperature indicated by the inlet temperature sensor 21. Here, it is detected that the temperature indicated by the outlet temperature sensor 22 and the temperature indicated by the inlet temperature sensor 21 are substantially the same, and the blower fan 11
By performing the control to increase the number of rotations, the evaporation capacity of the evaporator 19 can be increased and the amount of the liquid refrigerant entering the outlet pipe 19d can be reduced. As a result, the amount of the liquid refrigerant flowing back to the compressor (not shown) through the suction pipe 20 is reduced by detecting the inflow of the liquid refrigerant into the outlet pipe 19d and controlling the evaporation capacity of the evaporator 19. Therefore, it is possible to reduce the cooling waste heat radiated to the outside by heat conduction from the suction pipe 20.

As described above, by installing the outlet pipe of the evaporator in the air passage while separating it from the fin portion, the liquid refrigerant flows back to the compressor (not shown) through the suction pipe 20 during normal operation. Can be prevented, and the accumulator that retains the excess liquid refrigerant can be eliminated. As a result,
By reducing the amount of refrigerant, it is possible to improve the safety at the time of refrigerant leakage, and by reducing the heater capacity during defrosting by reducing the evaporator size by eliminating the accumulator, it is possible to reduce the The safety can be further improved. In addition, it is possible to reduce the amount of liquid refrigerant that flows back to the compressor through the suction pipe by detecting that the liquid refrigerant has entered the outlet pipe of the evaporator due to frost or the like and controlling the capacity of the evaporator. Therefore, it is possible to reduce the cooling waste heat radiated to the outside by heat conduction from the suction pipe.

In this embodiment, normally, all the refrigerant is vaporized before the outlet pipe 19d of the evaporator 19 and only the gas refrigerant passes through the outlet pipe 19d and the suction pipe 20 and a compressor (not shown). ), But the evaporation of the refrigerant is promoted by using the evaporator 19 having a high evaporation capacity, and a part of the straight pipe portion 19a or the corner portion 19b is used as a passage for the gas refrigerant like the outlet pipe 19d. Good. in this case,
The straight pipe portion 19a that was a passage for the gas refrigerant when frost formed
Since the liquid refrigerant enters a part of the above to maintain the evaporation ability, it is possible to reduce the amount of the liquid refrigerant flowing back to the compressor (not shown) through the suction pipe 20.

Further, in the present embodiment, the accumulator that retains the excess liquid refrigerant is abolished, but in consideration of the abnormal frosting condition that occurs when the door of the refrigerator is open for a long time,
An accumulator smaller than the conventional one can be installed between the outlet pipe 19d and the suction pipe 20. Even in this case, the liquid refrigerant hardly stays in the accumulator due to the usual frost formation, and the effect of reducing the amount of refrigerant and the effect of reducing the heater capacity during defrosting due to downsizing of the evaporator can be obtained.

(Fourth Embodiment) A fourth embodiment of the present invention will be described with reference to the drawings. The same components and operations as those of the third embodiment of the present invention are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 6 is a configuration diagram of a refrigerating cycle of a refrigerator according to the fourth embodiment of the present invention.

In FIG. 6, 19 is an evaporator of a refrigerator according to the fourth embodiment of the present invention, 30 is a compressor, 31 is a condenser, 32 is a cooling fan for cooling the condenser 31, and 33 is an expansion mechanism. A flammable hydrocarbon refrigerant R600a is used as the refrigerant.

Regarding the refrigerator configured as described above,
The operation will be described below.

When the freezer compartment 2 or the refrigerating compartment 3 is cooled, the refrigerant compressed by the compressor 30 is liquefied by the condenser 31, and the liquid refrigerant is decompressed by the expansion mechanism 33, and then directly cooled by the evaporator 19. The evaporator 19 is distributed to the pipe portion 19a and the corner portion 19b.
Is cooled. Similarly, by operating the blower fan 11, the indoor air in the freezer compartment 2 or the refrigerator compartment 3 is sent from the freezer compartment inlet 7 or the refrigerator compartment inlet 8 to the evaporator 19, and the fin portion 19c of the evaporator 19 is used. The air that has been heat-exchanged and cooled is sent from the discharge port 9 to the freezer compartment 2. In addition, freezer room 2
The air inside is sent to the refrigerator compartment 3 through a communication port (not shown). Here, the liquid refrigerant is usually the outlet pipe 1 of the evaporator 19.
All of the gas refrigerant is vaporized just before 9d, and only the gas refrigerant is discharged from the outlet pipe 19
It is returned to the compressor 30 through d and the suction pipe 20. At this time, since the outlet pipe 19d is separated from the fin portion 19c having a heat transfer effect and is installed in the air passage of the evaporator 19, the temperature is higher by several degrees Celsius than the straight pipe portion 19a and the corner portion 19b. Maintained at. As a result, the liquid refrigerant does not enter the suction pipe 20 during normal operation. In this case, the temperature indicated by the outlet temperature sensor 22 is the inlet temperature sensor 2
It is maintained at several degrees Celsius higher than the temperature indicated by 1.

The air that exchanges heat with the evaporator 19 is highly humid due to the inflow of outside air due to the opening and closing of the freezer compartment door 4 and the refrigerator compartment door 5 and the evaporation of the moisture of the stored food in the freezer compartment 2 and the refrigerator compartment 3. Since it is the converted air, the surface of the evaporator 19 is frosted. At this time, the evaporation capacity of the evaporator 19 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 19d, and a part of the liquid refrigerant is evaporated together with the suction pipe 2
It recirculates to the compressor 30 through 0. In this case, the temperature indicated by the outlet temperature sensor 22 is
Is almost the same as the temperature indicated by. Here, by detecting that the temperature indicated by the outlet temperature sensor 22 and the temperature indicated by the inlet temperature sensor 21 are substantially the same, the control for increasing the rotation speed of the cooling fan 32 is performed, whereby the condensing capacity of the condenser 31 is increased. To increase. As a result, the amount of liquid refrigerant existing in the entire condenser 31 increases and the amount of liquid refrigerant in the evaporator 19 decreases relatively, so that the refrigerant flows back to the compressor (not shown) through the suction pipe 20. The amount of liquid refrigerant can be reduced, and the cooling waste heat radiated to the outside by heat conduction from the suction pipe 20 can be reduced.

As described above, the outlet pipe of the evaporator is separated from the fin portion and installed in the air passage to prevent the liquid refrigerant from flowing back to the compressor 30 through the suction pipe 20 during normal operation. Therefore, the accumulator that retains the excess liquid refrigerant can be eliminated. As a result, by reducing the amount of refrigerant, it is possible to improve the safety at the time of refrigerant leakage, and by reducing the heater capacity during defrosting by the amount of evaporator miniaturization due to the elimination of the accumulator, the refrigerant The safety at the time of leakage can be further improved. In addition, even when it is difficult to improve the capacity of the evaporator due to frost or the like by detecting that the liquid refrigerant has entered the outlet pipe of the evaporator due to frost or the like and controlling the capacity of the condenser. It is possible to reduce the amount of liquid refrigerant that flows back to the compressor through the suction pipe, and reduce the cooling waste heat that is radiated to the outside by heat conduction from the suction pipe.

In this embodiment, when all the refrigerant is vaporized before the outlet pipe 19d of the evaporator 19 and only the gas refrigerant flows back to the compressor 30 through the outlet pipe 19d and the suction pipe 20 in the normal state. However, by using the evaporator 19 having a high evaporation capacity, the evaporation of the refrigerant is promoted and the straight pipe portion 19a
Alternatively, a part of the corner portion 19b may be used as a passage for the gas refrigerant, similarly to the outlet pipe 19d. In this case, when the frost formation progresses, the liquid refrigerant invades a part of the straight pipe portion 19a which was a passage of the gas refrigerant to maintain the evaporation ability. Therefore, the liquid refrigerant flowing back to the compressor 30 through the suction pipe 20 is maintained. The amount of refrigerant can be reduced.

Further, in this embodiment, the accumulator which retains the excess liquid refrigerant is abolished, but in consideration of the abnormal frosting condition that occurs when the refrigerator door is open for a long time,
An accumulator smaller than the conventional one can be installed between the outlet pipe 19d and the suction pipe 20. Even in this case, the liquid refrigerant hardly stays in the accumulator due to the usual frost formation, and the effect of reducing the amount of refrigerant and the effect of reducing the heater capacity during defrosting due to downsizing of the evaporator can be obtained.

(Fifth Embodiment) A fifth embodiment according to the present invention will be described with reference to the drawings. The same components and operations as those of the third embodiment of the present invention are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 7 is a schematic diagram of an evaporator of a refrigerator according to a fifth embodiment of the present invention.

In FIG. 7, 23 is an evaporator of a refrigerator according to the fifth embodiment of the present invention, 23a is a straight pipe portion of the evaporator 23, 23b is a corner portion of the evaporator 23, 23c is a fin portion of the evaporator 23, 23d is an outlet pipe of the evaporator 23, 20
Is a suction pipe, and 24 is an outlet temperature sensor for measuring the temperature of the outlet pipe 23d. A flammable hydrocarbon refrigerant R600a is used as the refrigerant.

Regarding the refrigerator configured as described above,
The operation will be described below.

When cooling the freezer compartment 2 or the refrigerating compartment 3, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is expanded by the expansion mechanism (not shown). After being decompressed by), the evaporator 23 is cooled by flowing through the straight pipe portion 23a and the corner portion 23b of the evaporator 23. Similarly, the operation of the blower fan 11 causes the freezer inlet 7
The indoor air of the freezer compartment 2 or the refrigerator compartment 3 is sent to the evaporator 23 from the refrigerator compartment intake port 8 and the fin portion 2 of the evaporator 23.
Air cooled by heat exchange in 3c is sent from the discharge port 9 to the freezer compartment 2. Further, the air in the freezer compartment 2 is sent to the refrigerating compartment 3 through a communication port (not shown). Here, normally, all of the liquid refrigerant is vaporized before the outlet pipe 23d of the evaporator 23, and only the gas refrigerant flows back to the compressor (not shown) through the outlet pipe 23d and the suction pipe 20. At this time, the outlet pipe 23
Since d is separated from the fin portion 23c having a heat transfer function and is installed in the air passage of the evaporator 23,
The temperature is maintained at a temperature higher by several degrees Celsius than that of the straight pipe portion 23a and the corner portion 23b. As a result, the liquid refrigerant does not enter the suction pipe 20 during normal operation. In this case, the outlet temperature sensor 2
The temperature indicated by 4 is maintained at substantially the same temperature as the temperature indicated by the indoor temperature sensor (not shown) of the freezer compartment 2.

The air that exchanges heat with the evaporator 23 is highly humid due to the inflow of outside air by opening and closing the freezing compartment door 4 and the refrigerating compartment door 5 and the evaporation of the moisture of the stored food in the freezing compartment 2 and the refrigerating compartment 3. Since it is the converted air, it frosts on the surface of the evaporator 23. At this time, the evaporation capacity of the evaporator 23 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 23d, and a part of the liquid refrigerant is evaporated together with the suctioned refrigerant 2
It recirculates through 0 to a compressor (not shown). In this case, the temperature indicated by the outlet temperature sensor 24 is lower than the temperature indicated by the indoor temperature sensor (not shown) of the freezer compartment 2 by several degrees Celsius. Here, by detecting that the temperature indicated by the outlet temperature sensor 24 suddenly drops and performing control to increase the rotation speed of the blower fan 11, the evaporation capacity of the evaporator 23 is increased and the outlet pipe is increased. The amount of liquid refrigerant entering the 23d can be reduced. As a result, the outlet pipe 2
By detecting the entry of the liquid refrigerant into 3d and controlling the evaporation capacity of the evaporator 23, the amount of the liquid refrigerant flowing back to the compressor (not shown) through the suction pipe 20 can be reduced, It is possible to reduce the cooling waste heat that is radiated to the outside by heat conduction from the suction pipe 20.

As described above, by installing the outlet pipe of the evaporator in the air passage while separating it from the fin portion, the liquid refrigerant flows back to the compressor (not shown) through the suction pipe 20 during normal operation. Can be prevented, and the accumulator that retains the excess liquid refrigerant can be eliminated. As a result,
By reducing the amount of refrigerant, it is possible to improve the safety at the time of refrigerant leakage, and by reducing the heater capacity during defrosting by reducing the evaporator size by eliminating the accumulator, it is possible to reduce the The safety can be further improved. In addition, it is possible to reduce the amount of liquid refrigerant that flows back to the compressor through the suction pipe by detecting that the liquid refrigerant has entered the outlet pipe of the evaporator due to frost or the like and controlling the capacity of the evaporator. Therefore, it is possible to reduce the cooling waste heat radiated to the outside by heat conduction from the suction pipe. Further, when comparing the temperature of the outlet pipe with the room temperature, one temperature sensor attached to the evaporator may be added, and this temperature sensor and the temperature sensor for detecting the end of defrosting can be shared.

In this embodiment, normally, all the refrigerant is vaporized before the outlet pipe 23d of the evaporator 23 and only the gas refrigerant passes through the outlet pipe 23d and the suction pipe 20 and a compressor (not shown). ), But the evaporation of the refrigerant is promoted by using the evaporator 23 having a high evaporation capacity, and a part of the straight pipe portion 23a or the corner portion 23b is used as a passage for the gas refrigerant like the outlet pipe 23d. Good. in this case,
When the frost formation progresses, the straight pipe portion 23a that was the passage of the gas refrigerant
Since the liquid refrigerant enters a part of the above to maintain the evaporation ability, it is possible to reduce the amount of the liquid refrigerant flowing back to the compressor (not shown) through the suction pipe 20.

Further, in this embodiment, the accumulator that retains the excess liquid refrigerant is abolished, but in consideration of the abnormal frosting condition that occurs when the refrigerator door is open for a long time,
An accumulator smaller than the conventional one can be installed between the outlet pipe 23d and the suction pipe 20. Even in this case, the liquid refrigerant hardly stays in the accumulator due to the usual frost formation, and the effect of reducing the amount of refrigerant and the effect of reducing the heater capacity during defrosting due to downsizing of the evaporator can be obtained.

Further, it is desirable that the outlet pipe 23d be installed on the windward side of the air passage having a relatively high temperature. In this case, the temperature drop is large when the liquid refrigerant enters the outlet pipe 23d, and the intrusion of the liquid refrigerant can be easily detected.

(Sixth Embodiment) A sixth embodiment of the present invention will be described with reference to the drawings. The same components and operations as those of the first embodiment of the present invention are designated by the same reference numerals and detailed description thereof will be omitted.

It is a block diagram of an evaporator of a refrigerator according to a sixth embodiment of the present invention.

In the figure, 25 is a sixth embodiment of the present invention.
The evaporator of the refrigerator by 25a, the straight pipe part of the evaporator 25,
25b is a corner of the evaporator 25, and 25c is the evaporator 25.
The fins and 25d are outlet pipes of the evaporator 25, and the outlet pipes 25d are not provided with fins 25c and are bare pipes. 25
e is an accumulator of the evaporator 25, and 26 is a suction pipe. Also, a flammable hydrocarbon refrigerant R600a as a refrigerant
Is used.

The accumulator 25e is formed by partially expanding the central portion of the outlet pipe 25d, and the outlet pipe 25d and the accumulator 25e are molded from a seamless single pipe to form the accumulator 25e. It is installed in the most upstream part of the 25 air passages. And the outlet pipe 25 integrated with the accumulator 25e
d is disposed below the evaporator 25, and a glass tube heater (not shown) which is a defrost heater is further provided below the evaporator 25.
Are arranged.

Further, the straight pipe portion 25a, the corner portion 25b, and the outlet pipe 25d, which are the pipes constituting the evaporator 25, are 1
It is formed by bending a tube of a book. Fin 25c
Is fixed in advance to the straight pipe portion 25a by pressure, and then bent to form the corner portion 25b, or one pipe is bent to form the straight pipe portion 25a and the corner portion 25b, and then the fin 25c is formed. There is a method of inserting it into an elongated hole and fixing it under pressure.

Regarding the refrigerator constructed as described above,
The operation will be described below.

When cooling the freezer compartment 2 or the refrigerating compartment 3, the refrigerant compressed by the compressor (not shown) is liquefied by the condenser (not shown), and the liquid refrigerant is expanded by the expansion mechanism (not shown). After being decompressed by), the evaporator 25 is cooled by flowing through the straight pipe portion 25a and the corner portion 25b of the evaporator 25. Similarly, the operation of the blower fan 11 causes the freezer inlet 7
The indoor air of the freezer compartment 2 or the refrigerator compartment 3 is sent to the evaporator 25 from the refrigerator compartment suction port 8 and the fin portion 2 of the evaporator 25.
Air cooled by heat exchange in 5c is sent from the discharge port 9 to the freezer compartment 2. Further, the air in the freezer compartment 2 is sent to the refrigerating compartment 3 through a communication port (not shown). Here, normally, all of the liquid refrigerant is vaporized before the outlet pipe 25d of the evaporator 25, and only the gas refrigerant flows back to the compressor (not shown) through the outlet pipe 25d and the accumulator 25e. At this time, since the outlet pipe 25d is separated from the fin portion 25c having a heat transfer effect and is installed in the air passage of the evaporator 25, the temperature is higher by several degrees Celsius than the straight pipe portion 25a and the corner portion 25b. Maintained at. As a result, the liquid refrigerant does not stay in the accumulator 25e during normal operation.

The air that exchanges heat with the evaporator 25 is highly humid due to the inflow of outside air due to the opening and closing of the freezer compartment door 4 and the refrigerating compartment door 5 and the evaporation of water in the stored food in the freezing compartment 2 and the refrigerating compartment 3. Since it is the converted air, the surface of the evaporator 25 is frosted. At this time, the evaporation capacity of the evaporator 25 decreases,
Excess liquid refrigerant that could not be evaporated enters the outlet pipe 25d, and a part of the liquid refrigerant stays in the accumulator 25e. However, since the accumulator 25e is installed in the air passage of the evaporator 25 having a large heat exchange amount, the liquid refrigerant surely evaporates, and the evaporated gas refrigerant passes through the suction pipe 26 and the compressor (not shown). Since it recirculates to, it is possible to prevent liquid backing to the compressor.

Further, since the outlet pipe 25d and the accumulator 25e are formed from a seamless single pipe, the welded portion between the accumulator 25e and the outlet pipe 25e can be eliminated and the chance of leaking the flammable refrigerant can be reduced. Therefore, the safety at the time of refrigerant leakage can be improved.

Further, since the pipe forming the evaporator 25 is formed by bending a single pipe, the welded portion of the entire evaporator 25 can be eliminated, and the chance of leaking the flammable refrigerant can be greatly reduced. Therefore, the safety at the time of refrigerant leakage can be further improved.

The outlet pipe 25d integrated with the accumulator 25e is arranged in the lower part of the evaporator 25, and a glass tube heater (not shown) which is a defrost heater is arranged in the lower part thereof. During frost, the accumulator 25e, whose temperature is unlikely to rise, can be quickly heated, so that the defrosting efficiency is improved and the input of the defrosting heater can be reduced.

[0071]

As described above, the invention according to claim 1 of the present invention is a refrigerator using a flammable refrigerant,
An evaporator, an outlet pipe of the evaporator installed so as to cross the air passage of the evaporator, and an accumulator connected to the outlet pipe for storing a liquid refrigerant, wherein the accumulator portion evaporates. It is possible to prevent the temperature from becoming lower than that of the fin unit, and as a result, reduce the amount of the appropriate refrigerant and reduce the input of the defrosting heater to improve the safety at the time of refrigerant leakage. be able to.

The invention according to claim 2 of the present invention is
In a refrigerator using a flammable refrigerant, an evaporator, an outlet pipe of the evaporator installed so as to traverse the air passage of the evaporator, and an intake pipe connected to the outlet pipe and returning a gas refrigerant. It is equipped with an evaporator that prevents the temperature of the outlet from becoming lower than that of the fins of the evaporator and eliminates the accumulator that does not easily heat up during defrosting, thus reducing the amount of refrigerant and defrosting. The input of the heater can be further reduced, and the safety at the time of refrigerant leakage can be improved.

The invention according to claim 3 of the present invention is
The invention according to claim 1 or 2, wherein a blower fan that sends air from the evaporator to the inside of the refrigerator, and an outlet pipe of the evaporator that is installed so as to cross an air passage of the evaporator,
With a detecting means for detecting that the liquid refrigerant has entered the outlet pipe, and using the control means for increasing the rotation speed of the blower fan when detecting that the liquid refrigerant has entered,
By adjusting the capacity of the evaporator, it is possible to cope with fluctuations in the operating state, reduce the amount of surplus refrigerant, and further reduce the accumulator capacity. At the same time, since the input of the defrosting heater can be reduced by reducing the amount of the refrigerant, the safety at the time of refrigerant leakage can be improved.

The invention according to claim 4 of the present invention is
In the invention according to any one of claims 1 to 3,
A condenser, a cooling fan for cooling the condenser, an evaporator, an outlet pipe of the evaporator installed so as to cross the air passage of the evaporator, and a liquid refrigerant having entered the outlet pipe. With the detection means for detecting, since the control means for increasing the rotation speed of the cooling fan when detecting the intrusion of the liquid refrigerant is used, by adjusting the capacity of the condenser even when the evaporator is frosted. It is possible to reduce the amount of surplus refrigerant generated due to changes in the operating state, and to further reduce the accumulator capacity. At the same time, by reducing the proper amount of refrigerant, the input of the defrosting heater can be reduced, and the safety at the time of refrigerant leakage can be improved.

The invention according to claim 5 of the present invention is
The invention according to claim 3 or 4, wherein an internal temperature sensor installed in a refrigerator, an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, Equipped with an evaporator temperature sensor installed in the outlet pipe, using a control means for detecting that the liquid refrigerant has entered from the temperature difference between the internal temperature sensor and the evaporator temperature sensor, of the excess refrigerant The occurrence can be detected more easily.

The invention according to claim 6 of the present invention is
In the invention according to claim 1, the accumulator is installed in the air passage of the evaporator, and the excess refrigerant in the accumulator can be surely evaporated in the air passage of the evaporator with a large heat exchange amount, and the compressor The liquid back of can be prevented.

The invention according to claim 7 of the present invention is
In the invention according to claim 1 or 6, the outlet pipe and the accumulator are molded from a seamless single pipe, the welded portion of the accumulator and the pipe can be eliminated, and the chance of leakage of flammable refrigerant can be reduced. .

The invention according to claim 8 of the present invention is
In the invention according to any one of claims 1 to 7, the pipe forming the evaporator is formed by bending one pipe, and a welded portion of the entire evaporator can be eliminated, The chance of leakage of flammable refrigerant can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of a refrigerator according to the present invention.

FIG. 2 is a configuration diagram of an evaporator of the refrigerator according to the same embodiment.

FIG. 3 is a configuration diagram of a second embodiment of a refrigerator according to the present invention.

FIG. 4 is a configuration diagram of an evaporator of the refrigerator according to the same embodiment.

FIG. 5 is a configuration diagram of an evaporator according to a third embodiment of a refrigerator according to the present invention.

FIG. 6 is a configuration diagram of a refrigeration cycle according to a fourth embodiment of the refrigerator according to the present invention.

FIG. 7 is a configuration diagram of an evaporator according to a fifth embodiment of a refrigerator according to the present invention.

FIG. 8 is a configuration diagram of an evaporator according to a sixth embodiment of a refrigerator according to the present invention.

FIG. 9 is a configuration diagram of a conventional refrigerator

FIG. 10 is a configuration diagram of a conventional refrigerator evaporator.

[Explanation of symbols]

1 refrigerator 11 Blower fan 18, 19, 23, 25 Evaporator 18d, 19d, 23d, 25d outlet pipe 18e, 25e Accumulator 20 Inhalation tube 21 Inlet temperature sensor 22, 24 Outlet temperature sensor 31 condenser 32 cooling fan

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25D 19/00 F25D 19/00 510D 510F (72) Inventor Kenichi Morishita 4-chome Takaidamoto-dori, Higashiosaka-shi, Osaka No. 2-5 Matsushita Refrigerator Co., Ltd. (72) Inventor Tetsuya Saito 4-2-5 Takada Hondori, Higashi Osaka-shi, Osaka Prefecture Matsushita Refrigerator Co., Ltd. (72) Inventor Makoto Oyamada Hon-Osaka City, Osaka 4-2-5 Matsushita Refrigeration Co., Ltd. F term (reference) 3L045 AA01 AA02 BA01 CA02 DA02 EA01 LA10 MA02 MA04 NA03 PA04

Claims (8)

[Claims] 1. A refrigerator using a flammable refrigerant,
A refrigerator comprising an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, and an accumulator connected to the outlet pipe and storing a liquid refrigerant. 2. A refrigerator using a flammable refrigerant,
A refrigerator provided with an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, and a suction pipe connected to the outlet pipe to recirculate a gas refrigerant. 3. A blower fan for sending air from the evaporator into the refrigerator, an outlet pipe of the evaporator installed so as to traverse the air passage of the evaporator, and a liquid refrigerant entering the outlet pipe. The refrigerator according to claim 1 or 2, further comprising: a detection unit for detecting, and a control unit for increasing the rotation speed of the blower fan when detecting the intrusion of the liquid refrigerant. 4. A condenser, a cooling fan for cooling the condenser, an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, and a liquid refrigerant in the outlet pipe. The refrigerator according to any one of claims 1 to 3, further comprising: a detecting unit that detects that the liquid refrigerant has entered, and a control unit that increases the rotation speed of the cooling fan when detecting that the liquid refrigerant has entered. . 5. An inside temperature sensor installed in a refrigerator, an evaporator, an outlet pipe of the evaporator installed so as to cross an air passage of the evaporator, and an evaporator installed in the outlet pipe. 5. The refrigerator according to claim 3 or 4, further comprising a container temperature sensor, and a control means for detecting that the liquid refrigerant has entered based on a temperature difference between the inside temperature sensor and the evaporator temperature sensor. 6. The refrigerator according to claim 1, further comprising an accumulator installed in an air passage of the evaporator. 7. The refrigerator according to claim 1 or 6, wherein the outlet pipe and the accumulator are formed from a seamless single pipe. 8. The pipe forming the evaporator is formed by bending a single pipe.
The refrigerator according to any one of 1.