JP3819815B2 - Refrigerant leak detection method for refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigerant leakage detection method for a refrigerator that detects refrigerant leakage.
[0002]
[Prior art]
When refrigerant leakage occurs in the refrigerator, the cooling capacity decreases and the compressor enters a continuous operation state. For this reason, a compressor will be in a high load operation state.
[0003]
Therefore, it is conceivable to adopt a function of detecting a refrigerant leak and stopping the refrigerator. However, by adopting a compressor protection circuit for high-load operation of the compressor, it is possible to cope with it temporarily, and the only main purpose of the refrigerator is to “store food at low temperatures”. Then, it is not adopted in an actual refrigerator.
[0004]
However, in recent years, refrigerators that employ combustible HC refrigerant as a refrigerant have been put on the market.
[0005]
Such a refrigerator is designed to reduce the total amount of refrigerant enclosed, or to gradually leak to the outside of the refrigerator even if refrigerant leakage occurs.
[0006]
However, even in such a refrigerator, the possibility of leaking inside the refrigerator is not zero.
[0007]
For this reason, in order to detect refrigerant leakage in a refrigerator using HC refrigerant, a temperature sensor (exit temperature sensor) is provided on the refrigerant outlet side of the cooler and a temperature sensor (inlet temperature sensor) is also provided on the refrigerant inlet side. A refrigerator has been proposed. In this refrigerator, the difference in detected temperature between the inlet temperature sensor and the outlet temperature sensor is monitored, and it is determined that the refrigerant is leaking when the temperature difference is equal to or greater than a predetermined temperature difference.
[0008]
[Problems to be solved by the invention]
However, in the refrigerator described above, it is necessary to provide a new sensor in order to detect refrigerant leakage.
[0009]
An object of the present invention is to detect refrigerant leakage with a simple configuration.
[0010]
In a refrigerator using a flammable refrigerant, if the compressor is operated when the refrigerant leaks, it assists the refrigerant leaking out of the refrigeration cycle.
[0011]
The present invention aims to prevent this.
[0012]
[Means for Solving the Problems]
The present invention detects the cooling abnormality by monitoring the temperature of the cooler 12 during the cooling operation in which the compressor 24 operates and the refrigerant circulates and the cool air from the cooler 12 is circulated in the cabinet by the fan 13. In the refrigerant leakage detection method for a refrigerator that estimates refrigerant leakage by detecting this cooling abnormality, the fan 13 is stopped while maintaining the operation of the compressor 24 when cooling abnormality is detected. The refrigerant leakage is detected by monitoring the temperature of the vessel 12.
[0013]
Further, the present invention is characterized in that the temperature of the cooler 12 described above is detected by a defrosting temperature sensor 36 used for detecting the end of defrosting.
[0014]
Furthermore, the present invention is characterized in that the compressor 24 is stopped when it is detected that the refrigerant is leaking.
[0015]
Further, the present invention is characterized in that the detection of the refrigerant leakage is not performed when it is detected that the door 5 of the refrigerator is opened.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 1 is a perspective view of the refrigerator-freezer of the first embodiment, FIG. 2 is a side sectional view thereof, and FIG. 3 is a view from the front, and is a view for explaining the arrangement of ducts. FIG. 4 is a circuit diagram for control.
[0018]
In FIG. 1, 1 is a refrigerator-freezer. Reference numerals 5, 6, and 7 denote doors of the refrigerator compartment 2, the freezer compartment 3, and the vegetable compartment 4, respectively. The door 5 is a revolving door, and the doors 6 and 7 are drawer type doors.
[0019]
In FIG. 2, 8 is an inner box whose front surface is opened, 9 is an outer box, and 10 is a foam heat insulating material. The heat insulating structure of the refrigerator / freezer 1 is formed by filling a foam heat insulating material 10 between the inner box 8 and the outer box 9.
[0020]
Inside the refrigerator-freezer 1, a refrigerator compartment 2, a freezer compartment 3, and a vegetable compartment 4 are partitioned and formed by partition walls 11, 11 in order from the top.
[0021]
A cooling chamber 14 in which a cooler 12 and a cooling air circulation fan 13 are disposed is formed at the back of the freezing chamber 3. In addition, a specific low temperature chamber 15 is provided in the lower part of the refrigerator compartment 2.
[0022]
Reference numeral 16 denotes a cold air duct. The cold air duct 16 is disposed on the back of the refrigerator compartment 2. The cold air duct 16 is for forming a cold air passage 18 for the refrigerating chamber that blows out the cold air from the cooler 12 from a cold air blowing hole 17 provided in the upper portion of the refrigerating chamber 2.
[0023]
21 is a damper. Regardless of whether the damper 21 is opened or closed, the cold air circulated from the cooler 12 by the cold air circulation fan 13 is supplied to the freezer compartment 3. When the damper 21 is open, the cool air from the cooler 12 is also supplied to the refrigerator compartment 2.
[0024]
Reference numeral 22 denotes a communication portion that allows the cooling chamber 14 and the damper 21 to communicate with each other. The cool air from the cooler 12 is supplied by the fan 13 to the damper 21 through the communication passage 22 and blown out from the cool air blowing hole 17 through the cold air passage 18 for the refrigerator compartment. When the damper 21 is closed, the supply of cold air to the refrigerator compartment 2 is stopped.
[0025]
23 is a machine room, and 24 is a compressor. Reference numeral 26 denotes a cold air return path for the vegetable room.
[0026]
In FIG. 3, reference numeral 25 denotes a vegetable room cold air supply path for supplying cold air to the vegetable room 4. The cold air supply path 25 for the vegetable room is mainly sucked in the cold air after going around the refrigerating room 2, flows downward, and flows into the vegetable room 4. The cold air supplied from the vegetable room cold air supply path 25 to the vegetable room 4 is returned to the cooling room 14 via the vegetable room cold air return path 26 shown in FIG.
[0027]
A schematic circuit diagram of this refrigerator-freezer is shown in FIG. As the refrigerant, HC refrigerant (here, isobutane) is used.
[0028]
24 is the compressor mentioned above. Reference numeral 27 denotes a condenser. Reference numeral 28 denotes a cooling fan for the condenser 27. Reference numeral 29 denotes a capillary tube (a decompression device). Reference numeral 12 denotes the above-described cooler. Reference numeral 13 denotes the aforementioned cold air circulation fan.
[0029]
During the cooling operation of the refrigerator-freezer, the flammable refrigerant circulates as indicated by the arrow, and the cold air cooled by the cooler 12 is circulated in the refrigerator by the cold air circulation fan 13 to be cooled.
[0030]
Reference numeral 30 denotes a control device that is a microcomputer that controls the refrigerator-freezer in an integrated manner.
[0031]
The control device 30 includes a CPU 31, a RAM 32 for storing various data, a ROM 33 for storing various control programs and various setting data. The RAM 32 of the control device 30 stores the internal temperature set by the user. The ROM 33 stores a refrigerator-freezer operation control program, a refrigerant leak detection program, and the like.
[0032]
Reference numeral 34 denotes a refrigerating room temperature sensor which is disposed inside the refrigerating room 2 and detects the temperature. Reference numeral 35 denotes a freezer temperature sensor, which is disposed inside the freezer room 3 and detects the temperature. Reference numeral 36 denotes a defrosting temperature sensor which is arranged directly or in the vicinity of the cooler 12 and detects the temperature of the cooler 12. Reference numeral 37 denotes a door opening / closing detection switch. In this embodiment, the opening / closing of the door 5 in FIG. 1 is detected.
[0033]
Reference numeral 38 denotes an interior lamp. When the control device 30 detects the opening of the door 5 by the door opening / closing detection switch 37, the control device 30 is driven to turn on.
[0034]
Reference numeral 21 denotes the aforementioned damper, whose opening and closing is controlled by the control device 30.
[0035]
A cooling operation similar to the conventional cooling refrigerator will be described.
[0036]
When the temperature of the freezer compartment 3 is increased by the freezer temperature sensor 35, the control device 30 starts the cooling operation. That is, the control device 30 turns on the compressor 24, the blower 28, and the cool air circulation fan 13, and opens the damper 21.
[0037]
Thereby, the combustible refrigerant circulates in the refrigeration cycle (compressor → condenser → decompressor → cooler → compressor), and the cooler 12 is cooled. The cool air in the cooler 12 is blown out from the cooling chamber 14 by the cool air circulation fan 13. Since the damper 21 is open, this cold air is blown out not only into the freezer compartment 3 but also into the refrigerator compartment 2. The cold air blown into the refrigerator compartment 2 circulates in the vegetable compartment 4 through the vegetable compartment cold air supply passage 25.
[0038]
Usually, a refrigerator-freezer is designed so that a refrigeration room and a vegetable room have a predetermined temperature difference, and a room in a refrigeration temperature zone (a refrigeration room and a vegetable room) has a storage temperature (e.g., The storage temperature of the refrigerator compartment is 3 ° C, and the storage temperature of the freezer compartment is -18 ° C).
[0039]
The control device 30 closes the damper 21 when the temperature of the refrigerator compartment 2 is lowered to a predetermined temperature (for example, 3 ° C.) by the refrigerator compartment temperature sensor 34. Thereby, the cool air of the cooler 12 is blown out only to the freezer compartment 3 by the cool air circulation fan 13.
[0040]
When the temperature of the freezer compartment 3 is lowered to a predetermined temperature (for example, −18 ° C.) by the freezer temperature sensor 35, the control device 30 stops the cooling operation. That is, the control device 30 turns off the compressor 24, the blower 28, and the cold air circulation fan 13.
[0041]
The same defrosting operation as that of the conventional refrigerator-freezer will be described.
[0042]
The control device 30 integrates the cooling operation time, detects the door open state based on a signal from the door open / close detection switch 37, and also integrates the door open time. And according to these both values, defrosting start timing is set in anticipation of the amount of frost formation.
[0043]
The control device 30 drives a defrost heater (not shown) provided in the cooler 12, and the frost attached to the cooler 12 is dissolved by heating the defrost heater. When the temperature detected by the defrosting temperature sensor 36 disposed in the vicinity of the cooler 12 itself or in the vicinity of the cooler 12 reaches a preset defrosting end temperature, the control device 30 sends the defrosting heater to the defrosting heater. Is stopped and the defrosting operation is completed.
[0044]
Next, the operation | movement at the time of detecting the leakage of the combustible refrigerant | coolant in this refrigerator-freezer is demonstrated.
[0045]
The control device 30 first detects a cooling abnormality caused by refrigerant leakage, and performs a refrigerant leakage detection operation when a cooling abnormality is detected.
[0046]
First, the cooling abnormality detection operation will be described.
[0047]
The control device 30 determines that the cooling is abnormal when the cooler 12 is not cooled for a long time after starting the cooling operation.
[0048]
That is, the control device 30 starts a timer count operation from the start of the cooling operation, detects the defrosting temperature sensor 35 when the timer count value reaches a predetermined value, and this value is determined from a preset value. If it is high, it is determined that the cooling is abnormal.
[0049]
The control device 30 performs a refrigerant leak detection operation when a cooling abnormality occurs. However, it is not performed in the following cases.
[0050]
This cooling operation is a case of pull-down operation (operation when the refrigerator is first installed, power is first supplied, and the internal temperature is first lowered to a predetermined storage temperature at a stroke). In this case, since it is the first cooling operation, there is a possibility that the freezer room could not be cooled to a predetermined temperature. In this case, the cooling abnormality is detected again after a predetermined time.
[0051]
Further, during the timer count operation, the refrigerant leak detection operation is not performed even when the door opening / closing detection switch 37 detects the opening of the door 5. This is because it is natural that the cause of the cooling abnormality is not the refrigerant leakage but the outflow of cool air inside the cabinet due to the opening of the door.
[0052]
Moreover, when it detects that the refrigerator compartment temperature is high by the refrigerator compartment temperature sensor 34, a refrigerant | coolant leak detection operation | movement is not performed. This is because there is a high possibility that a cooling abnormality has been caused because hot food or the like is put in the refrigerator compartment.
[0053]
Next, the refrigerant leak detection operation will be described.
[0054]
When detecting an abnormality in cooling, control device 30 performs a refrigerant leak detection operation.
[0055]
At the time of detecting the aforementioned cooling abnormality, the refrigerator-freezer is in the cooling operation. Here, the control device 30 stops the fan 13 for circulating cold air. Thereby, the flow of air in the cooler 12 stops. If there is no refrigerant leakage, the cooler 12 should be cooled.
[0056]
After a predetermined time, the control device 30 detects the temperature based on a signal from the defrosting temperature sensor 36, and determines that the cooling abnormality is caused by a cause other than the refrigerant leakage if the temperature has decreased to a predetermined temperature.
[0057]
If this temperature has not decreased to a predetermined temperature, it is determined that the refrigerant has leaked, and the control device 30 stops the compressor 24 and stops the blower 28.
[0058]
For this reason, the refrigeration cycle is stopped, and the flammable refrigerant can be prevented from actively leaking out of the refrigeration cycle.
[0059]
In this embodiment, the detection of the opening and closing of the door is performed only by the door 5, but this may naturally be performed by all the doors.
[0060]
In addition, the cooling abnormality is detected by the temperature value of the defrosting temperature sensor 36 after a predetermined time from the start of the cooling operation. Naturally, this detects a temperature change gradient and uses this gradient value as a reference. The cooling abnormality may be detected by comparing with the value.
[0061]
As described above, the present invention has been described based on the above-described embodiments. However, various alternatives, modifications, and variations are possible for those skilled in the art, and the present invention is not limited to the above-described various alternatives without departing from the spirit of the present invention. It includes examples, modifications or variations.
[0062]
【The invention's effect】
In the present invention, since the refrigerant leak is detected by stopping the fan 13 and monitoring the temperature of the cooler 12 after the stop, the refrigerant leak can be detected with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a diagram of a refrigerator-freezer according to an embodiment of the present invention.
FIG. 2 is a side sectional view of the refrigerator-freezer of this embodiment.
FIG. 3 is a front view of the refrigerator-freezer of this embodiment.
FIG. 4 is a schematic circuit diagram for explaining the control of the refrigerator-freezer of this embodiment.
[Explanation of symbols]
1 Refrigerator refrigerator (refrigerator),
2 Refrigerator room,
3 ... Freezer room,
4 ... Vegetable room,
12 .... Cooler,
13 .... Cooling fan (fan),
24 .... Compressor,
27 ... Condenser,
30 ... Control device,
34 .. Cold room temperature sensor,
35 .. Freezer temperature sensor,
36... Defrosting temperature sensor,
37 .... Door open / close detection switch.

Claims (4)

During the cooling operation in which the compressor (24) is operated and the refrigerant circulates and the cool air from the cooler (12) is circulated in the cabinet by the fan (13), the temperature of the cooler (12) is monitored and the cooling is performed. In the refrigerant leakage detection method for a refrigerator, which detects an abnormality and estimates that the refrigerant is leaking by detecting the cooling abnormality.
When the cooling abnormality is detected, the fan (13) is stopped while maintaining the operation of the compressor (24), and the temperature of the cooler (12) after the stop is monitored to thereby prevent refrigerant leakage. A method for detecting refrigerant leakage in a refrigerator, comprising detecting the refrigerant. The refrigerant leakage detection method for a refrigerator according to claim 1, wherein the temperature of the cooler (12) is detected by a defrosting temperature sensor (36) used for detecting the end of defrosting. The refrigerant leak detection method for a refrigerator according to claim 1 or 2, wherein the compressor (24) is stopped when it is detected that the refrigerant leaks. The refrigerant leakage according to any one of claims 1 to 3, wherein the refrigerant leakage is not detected when it is detected that the refrigerator door (5) is opened. Leak detection method.

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