JP2004125180A - Method of controlling refrigerator using inflammable refrigerant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further suppress the possibility of ignition by thinning inflammable refrigerant. <P>SOLUTION: In this method of controlling a refrigerator using the inflammable refrigerant, the temperature of a cooler 12 is monitored in cooling operation to detect a cooling abnormality, a cool air circulating fan 13 is stopped while maintaining the operation of a compressor 24 by detecting the cooling abnormality, and the leakage of refrigerant is detected by monitoring the temperature of the cooler 12 after the stoppage, and the cool air circulating fan 13 is operated when the leakage of refrigerant is detected. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for controlling a flammable refrigerant refrigerator using a flammable refrigerant.
[0002]
[Prior art]
When the refrigerant leaks in the refrigerator, the cooling capacity is reduced, and the compressor enters a continuous operation state. Therefore, the compressor enters a high load operation state.
[0003]
Thus, it is conceivable to employ a function of detecting a refrigerant leak and stopping the refrigerator. However, for the high-load operation of the compressor, the adoption of a compressor protection circuit is possible, and the only main purpose of the refrigerator is to store food at low temperature. Then, it is not adopted in the actual refrigerator.
[0004]
However, refrigerators employing flammable HC refrigerants as refrigerants have been released.
[0005]
Therefore, in order to detect refrigerant leakage in a refrigerator using HC refrigerant, a temperature sensor (outlet 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. Refrigerators have been proposed. In this refrigerator, the difference between the detected temperatures of the inlet temperature sensor and the outlet temperature sensor is monitored, and when the temperature difference exceeds a predetermined temperature difference, it is determined that the refrigerant is leaking.
[0006]
Upon detecting the refrigerant leakage, the refrigerator stops the fan in the refrigerator to prevent the flammable refrigerant from being charged into the refrigerator.
[0007]
[Problems to be solved by the invention]
By the way, the refrigerator of the HC refrigerant is designed so that the total amount of the enclosed refrigerant is reduced, and even if the refrigerant leaks, there is a high possibility that the refrigerant gradually leaks to the outside of the refrigerator. In such a refrigerator, even if leaked inside or outside the refrigerator, the amount is small. However, even in a small amount, flammable refrigerant will accumulate near the leaked point.
[0008]
The present invention is characterized by proposing a control method suitable for such a refrigerator.
[0009]
Still another object of the present invention is to detect refrigerant leakage with a simple configuration.
[0010]
[Means for Solving the Problems]
The present invention is characterized in that, in the control method of the refrigerator using the flammable refrigerant, the cooling air circulation fan 13 is operated when the refrigerant leakage is detected.
Further, the present invention is characterized in that, in the control method of the refrigerator using the flammable refrigerant, when the refrigerant leakage is detected, the condenser cooling fan 28 is operated.
[0011]
Further, the present invention monitors the temperature of the cooler 12 during the cooling operation in which the compressor 24 operates, the refrigerant circulates, and cool air from the cooler 12 is circulated in the refrigerator by the cool air circulation fan 13. An abnormality is detected, and when this cooling abnormality is detected, the cooling air circulation fan 13 is stopped while the operation of the compressor 24 is maintained, and the temperature of the cooler 12 after the stop is monitored to detect refrigerant leakage. It is characterized by doing.
[0012]
Further, the present invention is characterized in that the temperature of the above-described cooler 12 is detected by a defrosting temperature sensor 36 used for detecting the end of defrosting.
[0013]
Further, the present invention is characterized in that when it is detected that the refrigerant is leaking, the compressor 24 is stopped.
[0014]
Further, the present invention is characterized in that the above-described detection of refrigerant leakage is not performed when it is detected that the refrigerator door 5 is opened.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of the present invention will be described with reference to FIGS.
[0016]
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, for explaining the arrangement of ducts. FIG. 4 is a circuit diagram for control.
[0017]
In FIG. 1, reference numeral 1 denotes a refrigerator. 5, 6 and 7 are 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 doors.
[0018]
In FIG. 2, reference numeral 8 denotes an inner box having an open front surface, 9 denotes an outer box, and 10 denotes a foam heat insulating material. The heat insulating structure of the refrigerator 1 is formed by filling a foam heat insulating material 10 between the inner box 8 and the outer box 9.
[0019]
Inside the refrigerator 1, a refrigerator compartment 2, a freezer compartment 3 and a vegetable compartment 4 are partitioned by partition walls 11, 11 in order from the top.
[0020]
Behind the freezing room 3 is formed a cooling room 14 in which a cooler 12 and a cool air circulation fan 13 are disposed. In addition, a specific low-temperature chamber 15 is provided below the refrigerator compartment 2.
[0021]
16 is a cold air duct. This cold air duct 16 is provided at the back of the refrigerator compartment 2. The cool air duct 16 is for forming a cool air passage 18 for the cool room that blows cool air from the cooler 12 from a cool air outlet 17 provided in an upper portion of the cool room 2.
[0022]
21 is a damper. Regardless of the opening and closing of the damper 21, the cool air circulated from the cooler 12 by the cool air circulation fan 13 is supplied to the freezing compartment 3. When the damper 21 is open, cool air from the cooler 12 is also supplied to the refrigerator compartment 2.
[0023]
Reference numeral 22 denotes a communication part that connects the cooling chamber 14 and the damper 21. Cool air from the cooler 12 is supplied by the fan 13 to the damper 21 through the communication passage 22 and is blown out from the cool air outlet 17 through the cool air passage 18 for the refrigerator. When the damper 21 is closed, the supply of cool air to the refrigerator compartment 2 is stopped.
[0024]
23 is a machine room and 24 is a compressor. 26 is a cold air return path for the vegetable room.
[0025]
In FIG. 3, reference numeral 25 denotes a vegetable room cold air supply path for supplying cool air to the vegetable room 4. The cool air mainly after circulating through the refrigerator compartment 2 is sucked into the cool compartment supply passage 25 for the vegetable compartment, flows downward, and flows into the vegetable compartment 4. The cool air supplied from the vegetable room cool air supply passage 25 to the vegetable room 4 is returned to the cooling room 14 via the vegetable room cool air return line 26 shown in FIG.
[0026]
FIG. 4 shows a schematic circuit diagram of the refrigerator. The refrigerant uses an HC refrigerant (here, isobutane).
[0027]
Reference numeral 24 denotes the compressor described above. 27 is a condenser. Reference numeral 28 denotes a cooling fan (blower) for the condenser 27. 29 is a capillary tube (decompression device). Reference numeral 12 denotes the above-described cooler. Reference numeral 13 denotes the above-described cool air circulation fan.
[0028]
During the cooling operation of the refrigerator, the flammable refrigerant circulates as shown by the arrow, and the cool air cooled by the cooler 12 is circulated in the refrigerator by the cool air circulation fan 13 to be cooled.
[0029]
Reference numeral 30 denotes a control device which is a microcomputer that controls the refrigerator-freezer.
[0030]
The control device 30 includes a CPU 31, a RAM 32 for storing various data, and a ROM 33 for storing various control programs and various setting data. In the RAM 32 of the control device 30, the internal temperature and the like set by the user are stored. Further, the ROM 33 stores an operation control program of the refrigerator, a refrigerant leak detection program, and the like.
[0031]
Reference numeral 34 denotes a refrigerator compartment temperature sensor which is arranged inside the refrigerator compartment 2 and detects the temperature. A freezing room temperature sensor 35 is disposed inside the freezing room 3 to detect the temperature. Reference numeral 36 denotes a temperature sensor for defrost, which is disposed 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, which detects opening / closing of the door 5 in FIG. 1 in this embodiment.
[0032]
Reference numeral 38 denotes an interior light, which is turned on by the control device 30 when the control device 30 detects the opening of the door 5 by the door open / close detection switch 37.
[0033]
The damper 21 is controlled by the control device 30 to open and close.
[0034]
The cooling operation of the refrigerator-freezer similar to the conventional one will be described.
[0035]
When the temperature of freezer compartment 3 is increased by freezer compartment temperature sensor 35, 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.
[0036]
Thereby, the combustible refrigerant circulates through the refrigeration cycle (compressor → condenser → decompressor → cooler → compressor), and cooler 12 is cooled. Cool air of the cooler 12 is blown out of 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 cool air blown out to the refrigerator compartment 2 is circulated to the vegetable compartment 4 through the vegetable compartment cool air supply passage 25.
[0037]
Normally, a refrigerator-freezer is designed such that a temperature difference between a refrigerator room and a vegetable room is a predetermined temperature difference, and a room in a refrigerator temperature zone (a refrigerator room and a vegetable room) has a storage temperature (for example, The storage temperature of the refrigerator compartment is designed to be 3 ° C, and the storage temperature of the freezer compartment is set to -18 ° C).
[0038]
The control device 30 closes the damper 21 when the temperature of the refrigerator compartment 2 is reduced 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.
[0039]
The controller 30 stops the cooling operation when the temperature of the freezing room 3 is reduced to a predetermined temperature (for example, −18 ° C.) by the freezing room temperature sensor 35. That is, the control device 30 turns off the compressor 24, the blower 28, and the cool air circulation fan 13.
[0040]
A defrosting operation of this refrigerator-freezer similar to the conventional one will be described.
[0041]
The control device 30 accumulates the cooling operation time, detects the open state of the door by a signal from the door open / close detection switch 37, and also accumulates the time of the open state of the door. Then, in accordance with these two values, the defrosting start timing is set by estimating the amount of frost formation.
[0042]
The control device 30 drives a defrost heater (not shown) provided in the cooler 12, and the frost attached to the cooler 12 is melted by heating the defrost heater. Then, when the temperature detected by the defrost temperature sensor 36 arranged in the cooler 12 itself or in the vicinity of the cooler 12 reaches a preset defrost end temperature, the control device 30 sends a signal to the defrost heater. Is stopped, and the defrosting operation ends.
[0043]
Next, an operation for detecting the leakage of the flammable refrigerant in the refrigerator will be described.
[0044]
The control device 30 first detects a cooling abnormality caused by refrigerant leakage, and performs a refrigerant leakage detection operation when the cooling abnormality is detected.
[0045]
First, the operation of detecting a cooling abnormality will be described.
[0046]
The controller 30 determines that the cooling is abnormal when the cooler 12 is not cooled forever after the cooling operation is started.
[0047]
That is, the control device 30 starts the timer counting operation from the start of the cooling operation, detects the defrosting temperature sensor 35 when the timer count value reaches a predetermined value, and determines that the value is greater than a preset value. If it is high, it is determined that the cooling is abnormal.
[0048]
When a cooling abnormality occurs, the control device 30 performs a refrigerant leak detection operation. However, it is not performed in the following cases.
[0049]
This cooling operation is a pull-down operation (operation in which the refrigerator is first installed, power is first supplied, and the internal temperature is first reduced to a predetermined storage temperature at once). In this case, there is a possibility that the freezing compartment could not be cooled to the predetermined temperature because of the first cooling operation. In this case, the cooling abnormality is detected again after a predetermined time has passed.
[0050]
Further, even when the door 5 is detected to be open by the door open / close detection switch 37 during the timer count operation, the refrigerant leak detection operation is not performed. This is because the cause of the cooling abnormality is likely to be not the leakage of the refrigerant but the outflow of cold air in the refrigerator due to the opening of the door.
[0051]
When the refrigerator compartment temperature sensor 34 detects that the refrigerator compartment is at a high temperature, the refrigerant leak detection operation is not performed. This is because there is a high possibility that a cooling abnormality has been caused by putting high-temperature food or the like in the refrigerator compartment.
[0052]
Next, the refrigerant leak detection operation will be described.
[0053]
When detecting an abnormal cooling, the control device 30 performs a refrigerant leak detection operation.
[0054]
At the time when the above-mentioned cooling abnormality is detected, the refrigerator-freezer is in a cooling operation. Here, the control device 30 stops the cool air circulation fan 13. Thereby, the flow of the air in the cooler 12 stops. If there is no refrigerant leakage, cooler 12 should be cooled.
[0055]
After a predetermined time, the control device 30 detects the temperature based on a signal from the defrosting temperature sensor 36, and if the temperature has decreased to a predetermined temperature, determines that the cooling is abnormal due to a cause other than refrigerant leakage.
[0056]
If this temperature has not dropped to the predetermined temperature, it is determined that the refrigerant is leaking, and the control device 30 stops the compressor 24, stops the blower 28, and drives the cool air circulation fan 13 again. Since the compressor 24 is stopped, the refrigeration cycle is stopped, and the flammable refrigerant can be prevented from actively leaking out of the refrigeration cycle. Since the cool air circulation fan 13 is driven, even if the flammable refrigerant leaks into the refrigerator, the flammable refrigerant is diluted and the possibility of ignition can be reduced.
[0057]
Thus, in this embodiment, in the control method of the refrigerator using the flammable refrigerant, the compressor 24 operates to circulate the refrigerant and circulate the cool air from the cooler 12 into the refrigerator by the cool air circulation fan 13. During the cooling operation, the temperature of the cooler 12 is monitored to detect a cooling abnormality, and by detecting the cooling abnormality, the operation of the compressor 24 is stopped while the cooling air circulation fan 13 is stopped. By monitoring the temperature of the cooler 12 after stopping, refrigerant leakage is detected, and when the refrigerant leakage is detected, the cool air circulation fan 13 is operated. Therefore, the flammable refrigerant is diluted (thinned) and the possibility of ignition can be reduced.
[0058]
In this embodiment, the detection of the opening / closing of the door is performed only by the door 5, but this may be naturally performed by all the doors.
In this embodiment, when it is determined that the refrigerant is leaking, the control device 30 stops the compressor 24, stops the blower 28, and drives the cool air circulation fan 13 again. However, in the present application, when it is determined that the refrigerant leaks, the control device 30 may stop the compressor 24, continuously operate the blower 28, and drive the cool air circulation fan 13 again. Since the blower 28 is operated, even if the flammable refrigerant leaks out of the refrigerator, the flammable refrigerant is diluted and the possibility of ignition can be reduced.
[0059]
Further, the cooling abnormality is detected by the value of the temperature of the defrosting temperature sensor 36 after a predetermined time from the start of the cooling operation. However, this is, of course, detected by detecting the gradient of the temperature change and using the value of the gradient as a reference. The cooling abnormality may be detected by comparing with a value.
[0060]
As described above, the present invention has been described based on the above-described embodiments. However, various alternatives, modifications, or 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 thereof. It is intended to cover examples, modifications or variations.
[0061]
【The invention's effect】
As described above, according to the present invention, in the control method of the refrigerator using the flammable refrigerant, the refrigerant circulating fan 13 is operated when the refrigerant leakage is detected. Properties can be further suppressed.
As described above, the present invention operates the condenser cooling fan 28 when a refrigerant leak is detected in the method of controlling a refrigerator using a flammable refrigerant, so that the flammable refrigerant can be diluted and ignition can be prevented. Possibilities can be further suppressed.
[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 control of the refrigerator-freezer of this embodiment.
[Explanation of symbols]
1 ···· Refrigerator-freezer (flammable refrigerant refrigerator),
2 ... Refrigerator room,
3 ... Freezer,
4. Vegetable room,
12 ... cooler,
13. Cooling air circulation fan (fan),
24 ... Compressor,
27 ... condenser
28 ···· Condenser cooling fan (blower)
30 ... control device,
34 ... Refrigerator compartment temperature sensor
35 ··· Freezer temperature sensor
36 ... Temperature sensor for defrost,
37 Door open / close detection switch.

Claims (8)

A method of controlling a refrigerator using a combustible refrigerant, comprising: operating a cooling air circulation fan (13) when refrigerant leakage is detected. The temperature of the cooler (12) is monitored during a cooling operation in which the compressor (24) operates and the refrigerant circulates, and cool air from the cooler (12) is circulated in the refrigerator by the cool air circulation fan (13). Then, a cooling abnormality is detected, and by detecting the cooling abnormality, the cool air circulation fan (13) is stopped while the operation of the compressor (24) is maintained, and the cooler (12) after the stop is stopped. The method according to claim 1, wherein refrigerant leakage is detected by monitoring the temperature of (1). The control method for a combustible refrigerant refrigerator according to claim 2, wherein the temperature of the cooler (12) is detected by a defrosting temperature sensor (36) used to detect the end of defrosting. The method according to claim 2 or 3, wherein the compressor (24) is stopped when it is detected that the refrigerant is leaking. A method for controlling a refrigerator using a combustible refrigerant, comprising operating a condenser cooling fan (28) when refrigerant leakage is detected. During the cooling operation in which the compressor (24) operates and the refrigerant circulates and cool air from the cooler (12) is circulated in the refrigerator by the cool air circulation fan (13), the temperature of the cooler (12) is monitored. The cooling abnormality is detected, and by detecting the cooling abnormality, the cool air circulation fan (13) is stopped while the operation of the compressor (24) is maintained, and the cooler (12) after the stop is stopped. 6. The control method for a flammable refrigerant refrigerator according to claim 5, wherein a refrigerant leak is detected by monitoring a temperature of the refrigerant. The method according to claim 6, wherein the temperature of the cooler (12) is detected by a defrosting temperature sensor (36) used to detect the end of the defrosting. The method according to claim 6 or 7, wherein the compressor (24) is stopped when it is detected that the refrigerant is leaking.

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