JP2005207666A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine a refrigerant leakage state of a refrigeration cycle in which a combustible gas is sealed as a refrigerant. <P>SOLUTION: The refrigeration cycle 27 is composed of a compressor 24, a condenser 25, a switch valve 28 and evaporators 16, 19. A chillroom defrosting sensor 18 is mounted on the chillroom evaporator 16, and a refrigeration room defrosting sensor 21 is mounted on an accumulator 22 at the back of the refrigeration room evaporator 19. The refrigerant leakage state is determined when a reduction ratio of a detected temperature of the defrosting sensor 21 is over a specific value, and over a lower limit value in cooling the refrigeration room. Here, a compressor cooling fan 26 is operated to diffuse the leaked refrigerant. In a case of the chillroom, the refrigerant leakage state is determined on the basis of a rate of temperature rise and an upper limit value of the chillroom defrosting sensor 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refrigerator that uses a combustible gas such as a hydrocarbon-based refrigerant as a refrigerant, and more particularly to a refrigerator that detects leakage of the refrigerant.

  The refrigerant used in the refrigeration cycle of the refrigerator is a refrigerant that does not use a fluorocarbon gas such as HC refrigerant (hydrocarbon) so as not to adversely affect the environment from the viewpoint of protecting the ozone layer and global warming. It is desirable to adopt. However, since this HC refrigerant is flammable, it is not preferable that the refrigerant stays at a high concentration when leakage occurs for some reason from the refrigeration cycle.

  For example, Patent Document 1 discloses a conventional technique for solving the above-described problems. This is because the compressor cooling fan is stopped while the compressor is normally stopped, and the compressor cooling fan is always operated in preparation for leakage of flammable refrigerant from the machine room where the compressor is arranged. . However, in this case, since the compressor cooling fan is always operated, in addition to the noise generated by the operation of the always cooling fan, it is cooled even at a low room temperature so that the refrigerant stays in the condenser. Therefore, there is a problem that the refrigerant circulation is hindered after starting the compressor.

In view of this, the inventors have proposed the one disclosed in Patent Document 2 filed earlier in which refrigerant leakage is detected by detecting an increase and a decrease in the load (duty value) of the compressor. Thereby, when the refrigerant leakage state is detected, the above problem can be solved by operating the compressor cooling fan.
JP 2000-266439 A JP 2003-139446 A

However, in the above-described Patent Document 2, since the load fluctuation of the compressor is detected for detecting the refrigerant leakage, the compressor driving system is limited to the variable capacity type (inverter) model. Therefore, it cannot be applied to a refrigerator equipped with a compressor operated at a power frequency.
The present invention has been made in view of the above circumstances, and its purpose is to determine refrigerant leakage from a refrigeration cycle in a refrigerator that uses a flammable refrigerant in a refrigeration cycle even when the compressor is not of a variable capacity type. Accordingly, an object of the present invention is to provide a refrigerator that can prevent the leaked refrigerant from becoming a stagnant state at a high concentration.

In order to achieve the above object, the refrigerator of the present invention is a refrigerator in which a flammable gas is enclosed as a refrigerant in a refrigeration cycle including a compressor, a condenser, an expander, and an evaporator. The present invention is characterized in that the refrigerant leakage state of the refrigeration cycle is determined based on the amount of change in the temperature detected by the frost sensor.
When the refrigerant leaks from the refrigeration cycle, a large change occurs in the temperature detected by the defrost sensor. By utilizing this fact, it is possible to determine the refrigerant leak state by detecting an abnormal level change amount generated in the refrigerant leak state from the change amount. Therefore, by adopting the above configuration, it is possible to determine the refrigerant leakage state of the refrigeration cycle based on the detection temperature of the defrost sensor, and to determine the refrigerant leakage even in a configuration in which the load fluctuation of the compressor cannot be detected. Will be able to. As a result, it is possible to suppress the high-concentration refrigerant from staying by driving the fan or the like to diffuse the refrigerant when determining the refrigerant leakage state.

  The refrigerator of the present invention includes a compressor, a condenser, an expander and an evaporator corresponding to each of the refrigerator compartment and the freezer compartment, and a refrigeration unit provided with a switching valve for switching the refrigerant flow path on the upstream side of the expander. In a refrigerator in which a combustible gas is sealed as a refrigerant in a cycle, the refrigerant leakage state of the refrigeration cycle is determined based on the amount of change in temperature detected by a defrost sensor provided in the evaporator. .

By adopting the above configuration, even in a configuration in which an evaporator corresponding to each of the refrigerator compartment and the freezer compartment is provided as the refrigeration cycle, the refrigerant leakage state of the refrigeration cycle can be determined based on the detection temperature of the defrost sensor. become able to.
In the above configuration, in addition to the change amount of the detection temperature of the defrost sensor, a lower limit value or an upper limit value is set as a condition, and further, an increase rate or a decrease rate is set as a condition as a change amount. The refrigerant leakage state can be reliably determined.

  When the cooling fan for the compressor is provided, when the refrigerant leakage state is determined, the cooling fan can be driven to diffuse the leaked refrigerant, and the cooling fan is not provided. By stopping the compressor, the speed of refrigerant leakage can be reduced to suppress the staying state of high-concentration refrigerant.

  According to the refrigerator of the present invention, it is possible to determine the refrigerant leakage state of the refrigeration cycle based on the detection temperature of the defrost sensor, and by determining the refrigerant leakage in the configuration using the combustible gas as the refrigerant of the refrigeration cycle, A state in which the combustible gas that has come out stays at a high concentration can be prevented by driving the fan or stopping the compressor.

Hereinafter, an embodiment when the present invention is applied to a refrigerator having two evaporators will be described with reference to the drawings.
FIG. 3 shows a schematic overall configuration of the refrigerator, and the main body 1 is composed of a heat insulating box 2 and an inner box 3 having an open front. The heat insulation box 2 is partitioned by a heat insulation partition wall 4 into a refrigeration room 5 in a refrigeration temperature zone and a freezer compartment 6 in a refrigeration temperature zone, and the refrigeration room 5 and the freezer compartment 6 are completely independent. The structure is such that the cool air in each room does not mix.

  The interior of the refrigerator compartment 5 is partitioned into a refrigerator compartment 8 and a vegetable compartment 9 by a refrigerator compartment plate 7. The freezer compartment 6 includes a first freezer compartment 10 and a second freezer compartment 11. Each of the chambers 8 to 11 has doors 12 to 15 respectively. The refrigerator compartment evaporator 16 and the refrigerator compartment cooling fan 17 are arranged on the back of the refrigerator compartment evaporator cover 16a arranged on the back side of the vegetable compartment 9, and the refrigerator compartment cooling fan 17 is used to change the temperature inside the cabinet and to open and close the door. Operation control is performed accordingly. The refrigerator compartment defrost sensor 18 is arranged to detect the temperature of the refrigerator compartment evaporator 16.

  A freezer compartment evaporator 19 and a freezer compartment cooling fan 20 are provided on the back of the freezer compartment evaporator cover 19 a provided on the back side of the first freezer compartment 10 and the second freezer compartment 11. The freezer compartment defrost sensor 21 is disposed so as to detect the temperature of the freezer evaporator 19 or the accumulator 22 (see FIG. 4) (in this embodiment, the temperature of the accumulator 22 is detected). A compressor 24, a condenser 25 (see FIG. 4), and a compressor cooling fan 26 are disposed in the machine room 23 below the back wall of the refrigerator body 1.

  FIG. 4 shows the configuration of the refrigeration cycle 27, and the discharge port of the compressor 24 is connected to the inlet port of the switching valve 28 via the condenser 25. The switching valve 28 is configured to be able to electrically switch and control two outlet ports, and the first outlet port is connected to the refrigerator compartment evaporator 16 via the refrigerator capillary 29, and this refrigerator compartment evaporator. 16 is connected to the inflow side of the freezer evaporator 19. The second outlet port of the switching valve 28 is connected to the suction port of the freezer evaporator 19 via the freezing capillary 30. The discharge port of the freezer compartment evaporator 19 is connected to the suction port of the compressor 24 via the accumulator 22.

  By adopting the above-described configuration, when the freezer compartment 6 is cooled, the second output port of the switching valve 28 is controlled to be connected to the freezing capillary 30 side, and the liquid condensed thereby The refrigerant expands in the freezing capillary 30 and cools in the freezer compartment evaporator 19 and then returns to the compressor 24. Further, when the refrigerator compartment 5 is cooled, control is performed so that the first output port of the switching valve 28 is opened and connected to the refrigerator capillary 29 side, and the liquid refrigerant condensed thereby expands in the refrigerator capillary 29 and is stored in refrigerator. After cooling in the chamber evaporator 16, the refrigerant returns to the compressor 24 via the freezer evaporator 19.

  At this time, when the freezer compartment is cooled, the refrigerant flows in the order of the freezing capillary 30, the freezer compartment evaporator 19, and the accumulator 22, and the cold air circulates in the refrigerator by the operation of the freezer compartment cooling fan 20, and the first and second freezer compartments 10 are supplied. , 11 is cooled. Then, when the switching valve 22 is switched and the refrigerant flow path is switched from the freezer compartment 6 side to the refrigerating compartment 5 side, the refrigerant flows into the refrigerating compartment evaporator 16, and the refrigerating compartment fan 8 is operated so that the refrigerating storage compartment 8 and the vegetable compartment 9 are connected. Come to cool.

  In the refrigeration cycle 27 having the above-described configuration, the refrigerant circulating inside is compressed by the compressor 24 and flows out from the discharge port in the state of high-pressure liquid refrigerant, and after being cooled, the compressor 24 is expanded in the low-pressure gas state. Return to. In the present invention, it is intended to detect that the refrigerant leaks outside for some reason in the circulation process of the refrigerant. In this embodiment, the refrigerant generated when the above-described refrigerant state is in a high pressure state. It detects leaks.

Here, the “high pressure side” and the “low pressure side” in the refrigeration cycle 27 are divided as follows. That is, the refrigerant flow path from the discharge port of the compressor 24 through the condenser 25 and the switching valve 28 to the refrigeration capillary 29 and the freezing capillary 30 is the “high-pressure side”, and the compressor 24 from the downstream side from this side. The refrigerant flow path to the suction port is the “low pressure side”.
Next, the electrical configuration will be described with reference to FIG. The control circuit 31 includes a CPU, a ROM, a RAM, peripheral circuits, and the like, and performs overall control according to a program. The control circuit 31 is connected to the following various sensors in addition to the above-described refrigerating room defrosting sensor 18 and freezing room defrosting sensor 21, and in addition to loads such as the compressor 24 and the switching valve 28. Various loads are connected.

  Regarding the sensor, the temperature sensor 32 for the refrigerator compartment that detects the temperature in the refrigerator compartment 5, the temperature sensor 33 for the refrigerator compartment that detects the temperature in the freezer compartment 6, the outside air temperature sensor 34 that detects the outside temperature, and the refrigerator compartment door. A refrigerator door switch 35 for detecting the opening / closing of 10 is connected to the control circuit 31. The load connected to the control circuit 31 includes an optical plasma deodorizing device 36, a damper 37, an interior lamp 38, a display 39 made of liquid crystal, an alarm 40 as a notification means, a refrigerator compartment defrost heater 41, There is a freezer compartment evaporator defrost heater 42 and the like.

The interior lamp 38 is controlled to be turned on by the control circuit 31 when the opening of the door 10 of the refrigerator compartment 5 is detected by the refrigerator compartment door switch 35. The refrigerating room cooling fan 17 and the freezing room cooling fan 20 are driven when the refrigerating room 5 and the freezing room 6 are cooled, respectively. However, the refrigerating room cooling fan 17 is stopped when the opening of the refrigerating room door switch 35 is detected. Controlled.
The refrigerator compartment evaporator defrost heater 41 and the refrigerator compartment evaporator defrost heater 42 are provided in the refrigerator compartment evaporator 16 and the refrigerator compartment evaporator 19, respectively. When the accumulated operation time of the compressor 24 reaches a predetermined time, the refrigerator compartment evaporator defrost heater 41 and the refrigerator compartment evaporator defrost heater 42 are energized to adhere to the refrigerator compartment evaporator 16 and the evaporator 20 for freezing. Frost is melted.

  The refrigerator compartment defrost sensor 18 and the freezer compartment defrost sensor 21 are composed of temperature sensors. When these sensors 18 and 21 detect a predetermined temperature or more, the defrosting is completed and the defrost heaters 41 and 42 are installed. The power is cut off. The indicator 39 is provided on a panel disposed on the door 12 of the refrigerator compartment 5 and displays the temperature of the refrigerator compartment 5 and the freezer compartment 6. The alarm 40 includes a vibrator and is provided in the panel.

Moreover, the freezer compartment evaporator temperature sensor 43 and the freezer compartment evaporator outlet temperature sensor 44 for detecting those temperatures are provided at the inlet and the outlet of the freezer compartment evaporator 19, and these temperature sensors 43, Reference numeral 44 is connected to the control circuit 31, and the detection signal is inputted.
Next, the operation of the present embodiment, that is, the operation of detecting the refrigerant leakage state of the refrigeration cycle 27 will be described with reference to FIGS. 1 and 2 and FIGS. The control circuit 31 executes the refrigerant leakage determination program shown in FIGS. 1 and 2 while executing a normal cooling operation, and determines the state of refrigerant leakage from the refrigeration cycle 27. FIGS. 1 and 2 show a refrigerant leakage state determination program executed by the control circuit 31.

Further, in this embodiment, a description will be given of determining a case where refrigerant leakage occurs on the high pressure side of the refrigeration cycle 27 described above. Although the pressure on the discharge port side of the compressor 24 varies depending on the load state at that time, generally, the following relationship is established.
Pressure during cooling in the refrigerator compartment> Pressure during cooling in the freezer compartment> Pressure during stoppage FIGS. 6 to 8 show changes in temperature of the defrost sensors 18 and 21 when the refrigerant leaks from the high-pressure side during operation of the refrigeration cycle 27. In this configuration, the freezer compartment defrost sensor 21 is a general configuration provided in the accumulator 22, and actually detects the temperature of the accumulator 22.

  In the normal cooling operation, the freezer compartment cooling operation and the refrigerator compartment cooling operation are executed alternately. At this time, the temperature change of the freezer compartment defrost sensor 21 during each cooling operation is as follows. First, when the switching valve 28 is switched to a state in which the outlet port on the freezing capillary 30 side is opened, the freezing chamber cooling operation is started, and the refrigerant decompressed by the freezing capillary 30 is vaporized by the freezing chamber evaporator 19, during which the accumulator 22 is accumulated. At the same time, the temperature decreases (in FIG. 6, the period of freezing room cooling (1)).

  The temperature decrease rate immediately after the start of the freezer cooling operation is large, and thereafter the temperature decrease rate gradually decreases. The accumulator 22 has a refrigerant quantity adjusting function, and usually the surplus refrigerant exists in the accumulator 22. In this state, if refrigerant leakage occurs for some reason from the high pressure side, the temperature of the accumulator 22 decreases due to rapid vaporization of the refrigerant as the pressure in the refrigeration cycle 27 decreases. The temperature decrease rate at this time becomes larger than the normal case as shown in the temperature fluctuation during the freezer cooling (2) period of FIG. When a temperature decrease due to such refrigerant leakage occurs, a temperature decrease that cannot occur in the normal cooling operation occurs, and reaches a lower limit value TL1, which is one of the set determination criteria.

  When the control program 31 starts the refrigerant leakage determination program, it first determines whether or not the room temperature is lower than 15 ° C. by inputting a detection signal from the outside air temperature sensor 34 (step S1). Here, in the case of “NO”, that is, in the case where the room temperature is 15 ° C. or higher, the control circuit 31 needs to cool the compressor 24 and the condenser 25. The cooling operation is executed (steps S2 and S3), and thereafter, steps S1 to S3 are repeatedly executed.

  If “YES” in the step S1, that is, if the room temperature is lower than 15 ° C., the cooling capacity is not so much required, so the control circuit 31 performs the normal cooling operation with the compressor cooling fan 20 turned off. (Steps S4 and S5). Next, in the cooling operation control, when the freezer compartment is in a cooling state, that is, when the output port of the switching valve 28 is set to the freezing capillary 30 side, the control circuit 31 determines that the freezer compartment is in a cooling state. Then, the amount of change in the detected temperature of the freezer compartment defrost sensor 21 is determined (step S7).

Here, the control circuit 31 determines whether or not the decrease rate of the temperature detected by the freezer compartment defrost sensor 21 is 8 K (Kelvin) (8 ° C.) or more per 2 minutes. In the case of normal operation, such a rapid temperature change does not occur. Therefore, the determination is “NO” and the process returns to step S1.
And when refrigerant | coolant leakage has generate | occur | produced, it will be judged as "YES" by step S7, and next, the detected temperature of the freezer compartment defrost sensor 21 will be higher than the temperature set to lower limit TL1. Determine if it has dropped. If the detected temperature starts to rise before reaching the lower limit value TL1, the control circuit 31 determines “NO” and returns to step S1. When the detected temperature reaches the lower limit value TL1, the control circuit 31 determines “YES” and determines that the refrigerant is leaking (see step S9 in FIG. 2).

This situation is as shown in FIG. That is, when the refrigerant leaks during the freezer compartment cooling (2) period and the temperature detected by the freezer compartment defrost sensor 21 decreases rapidly, and the rate of decrease exceeds 8K / 2 minutes, that is, 2 minutes. When the detected temperature decreases by 8 ° C. or more, it is determined that the refrigerant is leaking.
When the refrigerant leakage state is determined in this way, the control circuit 31 is used at a particularly high voltage, such as the optical plasma deodorizing device 36, as a specific load control, which is not shown in the flowchart in FIG. The load to be controlled is controlled so as to be stopped for the purpose of preventing the refrigerant gas from being ignited. Thereby, when refrigerant gas is leaking in the warehouse, it is possible to prevent ignition. In addition, in the case of providing a function to release negative ions etc. outside the main body like a recent refrigerator, the refrigerant leakage state was determined in response to the possibility of using a high voltage at the ion generation unit. Sometimes, it is preferable to control the power supply to stop once.

  On the other hand, when the refrigerating room is cooled, that is, when the outlet port of the switching valve 28 is set so that the refrigerating capillary 29 side opens, the control circuit 31 determines “NO” in step S6 and proceeds to step S10. To do. In this state, the control circuit 31 determines whether or not the rate of increase in the temperature detected by the refrigerating room defrost sensor 18 exceeds 3 K / 2 minutes and exceeds the temperature set as the upper limit value TU (steps S11 and S12). ). If both of these steps are “NO”, the process returns to step S1. And in the case of "YES", the control circuit 31 determines a refrigerant leak state (step S9).

In the above-described case, as will be described later, a change in the detected temperature of the freezer compartment defrost sensor 21 is also taken as a determination condition, so that a more reliable refrigerant leakage state can be determined.
This situation is as shown in FIG. That is, the temperature change of the refrigerator compartment defrost sensor 18 and the freezer compartment defrost sensor 20 at the time of refrigerant | coolant leakage from a high voltage | pressure side during the period of refrigerator compartment cooling (2) is shown. When the refrigerator compartment is cooled (period indicated by refrigerator compartment cooling (1) in the figure), the refrigerator compartment evaporator 16 and the freezer compartment evaporator 19 are connected in series as shown in FIG. Therefore, when the refrigerating room cooling is started, the temperature of the refrigerating room evaporator 16 and the temperature of the freezing room evaporator 19 (detected temperatures of the defrost sensors 18 and 21) change so as to approach the same temperature. That is, the temperature of the refrigerator compartment evaporator 16 decreases and the temperature of the freezer compartment evaporator 19 increases.

  And as above-mentioned, if a refrigerant | coolant leakage generate | occur | produces during the period of refrigerator compartment cooling (2), since the refrigerant | coolant vaporizes, the temperature will reduce temporarily rapidly. On the other hand, in the refrigerator compartment evaporator 16, there is little liquid refrigerant and the temperature in the refrigerator compartment 5 is higher than the temperature in the freezer compartment 6, so that the cooling is insufficient and the temperature of the refrigerator compartment evaporator 16 rises. become. At this time, the rate of increase in the detected temperature of the refrigerator compartment defrost sensor 18 (for example, when there is an increase of 3 ° C. or more in 2 minutes) and the upper limit TU, the rate of decrease in the detected temperature of the freezer compartment defrost sensor 21 (for example, If there is a drop of 8 ° C. or more in 2 minutes) and the lower limit value TL1, it is determined that the refrigerant is leaking.

  Next, when the compressor 24 is stopped during a period in which neither the freezing room nor the refrigerating room is cooled, the process proceeds to step S13 via steps S6 and S10. In this case, since the compressor 24 is not in operation, even if a refrigerant leak occurs, the outflow speed is slow, and as a result, the temperature change of the defrost sensors 18 and 21 as described above becomes slow. Therefore, the control circuit 31 sets whether or not the rate of decrease in the temperature detected by the freezer compartment defrost sensor 21 is 3K or more per 2 minutes as a condition for determining refrigerant leakage, and a higher value than in the above case. The refrigerant leakage state is determined based on whether the lower limit value TL2 (<TL1) or less is reached (steps S13, 14, 9).

  FIG. 8 shows a state of change in the detected temperature of the freezer compartment defrost sensor 21 when the refrigerant leaks while the compressor 24 is stopped. When the compressor 24 is stopped, the discharge pressure is reduced. Therefore, when leakage occurs, the speed of leakage from the same opening is slower than when the compressor 24 is in operation. As described above, refrigerant is present in the accumulator 22, and the temperature decrease rate is reduced as compared with the operation of the compressor 24. At this time, it is determined that the refrigerant has leaked when the set reduction rate and the lower limit value TL2 are reached while the compressor 24 is stopped.

  As described above, when the refrigerant leakage state is determined, the control circuit 31 then turns on the compressor cooling fan 26 to forcibly diffuse the refrigerant in the gas state, and perform normal cooling operation. (Steps S15 and S16). If this operation is continued for 8 minutes, the control circuit 31 once ends the countermeasure for the refrigerant leakage (determined as “YES” in step S17). Here, the time of 8 minutes is set because the time is set so that the refrigerant gas having a high concentration can be sufficiently diffused, and this varies depending on the state of the model and load. An appropriate time can be set.

  Subsequently, the control circuit 31 determines whether the compressor cooling fan 26 is operated or stopped depending on whether the room temperature is lower than 15 ° C., and performs the normal cooling operation (steps S18 to S22). If this state continues for 6 hours and the temperature detected by the freezer compartment defrost sensor 21 does not become lower than 21 ° C., it is determined that the refrigerant is leaking. In this determination program, when the refrigerant leakage is determined and it is determined that there is a refrigerant leakage state, the program stagnates in a state where the above steps S18 to 23 are repeated.

Actually, when the refrigerant leaks, the cooling operation becomes abnormal. Therefore, in the normal cooling operation control program (steps S20 and S22), the cooling abnormality is determined to stop the compressor or Measures such as notification operations will be taken.
In addition, in step S23 described above, it is determined “YES”, that is, the cooling function is restored and the cooling operation is normally performed. This is a case where the refrigerant leakage state determination itself is an erroneous determination, and the sensor temperature may temporarily fluctuate greatly due to the interaction between the defrost sensors 18 and 21 and various operations. This is because the refrigerant leakage state may be determined.

However, even in this case, when it is confirmed that the cooling capacity has been recovered and the normal cooling operation state has been achieved while executing Steps S18 to S23, the control circuit 31 determines that there is no refrigerant leakage, and Step S1. To return to. As a result, even in the case of erroneous determination, it is possible to return to the normal cooling operation, so that problems such as cooling failure can be avoided.
According to the present embodiment, the refrigerant leakage state of the refrigeration cycle 27 is determined based on a decrease rate and an increase rate that are changes in detected temperatures of the freezer compartment defrost sensor 21 and the refrigerator compartment defrost sensor 19. As a result, the refrigerant leakage state can be detected even when the load variation of the compressor 24 cannot be detected.

In the above case, the refrigerant leakage state is determined based on the decrease rate of the freezer defrost sensor 21 during the freezer cooling operation, and based on the increase rate of the refrigerating chamber defrost sensor 19 during the refrigerating chamber cooling operation. Since the refrigerant leakage state is determined, it is possible to determine that there is a possibility of refrigerant leakage at an early stage according to an appropriate amount of change except for disturbance.
In addition, the refrigerant leakage state is determined in addition to the amount of change in the detected temperature of the defrost sensors 19 and 21 described above, and the lower limit values TL1 and TL2 of the detected temperature of the freezer compartment defrost sensor 21 or the refrigerator compartment defrost sensor 19 By providing the upper limit value TU of the detected temperature, it is determined when both are detected, so that more reliable determination processing can be performed.

Furthermore, when the refrigerant leakage state is determined, the compressor cooling fan 26 is forcibly operated so that the leaked refrigerant gas can be sufficiently diffused so as not to be in a staying state at a high concentration. Even in an environment where there is a risk of ignition, it is possible to prevent fires from occurring while performing normal cooling operation.
In addition, even if it is erroneously determined that the refrigerant leakage state has been determined, the cooling operation is continued, so that the refrigerant gas assumed to have leaked by operating the compressor cooling fan 26 is diffused. However, when the cooling function is restored, the operation can be continued as it is.

While the compressor 24 is stopped, the determination is made under the condition that the amount of change in the temperature detected by the freezer compartment defrost sensor 21 is set to be smaller than when the compressor 24 is in operation. The refrigerant leakage state can be determined even when the compressor 24 is stopped, which could not be detected by the detection operation due to the load fluctuation.
The present invention is not limited to the above embodiment, and can be modified or expanded as follows.

In the said embodiment, although demonstrated by the case where it applied to the refrigerator of the structure provided with two evaporators 16 and 19, it is not restricted to this, It can also apply to the refrigerator of the structure provided with one evaporator.
In the above embodiment, when the refrigerant leakage state is determined, the compressor cooling fan 26 is continuously operated for a certain period of time, but may be operated intermittently. With this configuration, it is possible to reduce the concentration of the leaked refrigerant while suppressing the generation of useless power consumption due to the operation of the compressor cooling fan 26, and further it is possible to suppress the refrigerant stagnation amount at low room temperature.

  When the refrigerant leakage state is determined, the compressor cooling fan 26 is operated for a certain period of time so that the leakage of the refrigerant gas leaked can be appropriately executed. Instead of this, or in combination with this, the compressor The operation of 24 may be stopped for a certain time. Thereby, the speed at which the refrigerant gas leaks can be suppressed, and the concentration of the leaked gas can be suppressed low.

  When the refrigerant leakage state is determined, the switching valve 28 can be controlled to be in an open state. As a result, for example, when the switching valve 28 is in the closed state, the refrigerant can be released and diffused to the outside at an early stage as compared with the amount of refrigerant remaining in the refrigeration cycle 27, thereby improving safety. Will be able to.

Flowchart (No. 1) of a refrigerant leakage state determination program showing an embodiment of the present invention Flowchart of refrigerant leakage state determination program (part 2) Longitudinal side view of overall configuration Configuration diagram of refrigeration cycle Electrical block diagram The figure which shows the defrost sensor temperature change of refrigerant | coolant leak generation | occurrence | production at the time of freezer compartment cooling The figure which shows the defrost sensor temperature change of the refrigerant | coolant leak generation | occurrence | production at the time of refrigerator compartment cooling The figure which shows the defrost sensor temperature change of the refrigerant | coolant leak generation | occurrence | production during a compressor stop

Explanation of symbols

In the drawings, 5 is a refrigerator compartment, 6 is a refrigerator compartment, 16 is a refrigerator compartment evaporator, 17 is a refrigerator compartment cooling fan, 18 is a refrigerator compartment defrost sensor, 19 is a refrigerator compartment evaporator, 20 is a refrigerator compartment cooling fan, 21 Is a freezer defrost sensor, 22 is an accumulator, 23 is a machine room, 24 is a compressor, 25 is a condenser, 26 is a compressor cooling fan, 27 is a refrigeration cycle, 28 is a switching valve, 29 is a refrigerated capillary (expander) ), 30 is a freezing capillary (expander), 31 is a control circuit, 36 is an optical plasma deodorizing device, and 38 is an interior lamp.

Claims (14)

In a refrigerator in which combustible gas is sealed as a refrigerant in a refrigeration cycle including a compressor, a condenser, an expander, and an evaporator,
A refrigerator configured to determine a refrigerant leakage state of the refrigeration cycle based on a change amount of a temperature detected by a defrost sensor provided in the evaporator. The refrigerator according to claim 1,
A refrigerator configured to determine the refrigerant leakage state of the refrigeration cycle on the condition that the detected temperature of the defrost sensor is changed in addition to the change amount of the detected temperature in addition to the lower limit value of the detected temperature. Combustible gas is supplied as a refrigerant to a refrigeration cycle that includes a compressor, a condenser, an expander and an evaporator corresponding to each of the refrigerator compartment and the freezer compartment, and a switching valve that switches the refrigerant flow path on the upstream side of the expander. In the enclosed refrigerator,
A refrigerator configured to determine a refrigerant leakage state of the refrigeration cycle based on a change amount of a temperature detected by a defrost sensor provided in the evaporator. The refrigerator according to claim 3,
A refrigerator configured to determine the refrigerant leakage state of the refrigeration cycle on the condition that the detected temperature of the defrost sensor is changed in addition to the amount of change of the detected temperature in addition to the lower limit value of the detected temperature. The refrigerator according to claim 3,
In addition to the amount of change in the detected temperature of the defrost sensor, an upper limit value and a lower limit value of the detected temperature are provided, and the refrigerant leakage state of the refrigeration cycle is determined on the condition that the detected temperature has changed beyond these. A refrigerator characterized by. The refrigerator according to any one of claims 3 to 5,
During cooling of the freezer compartment, the refrigerant leakage state of the refrigerating cycle is determined based on a decrease rate of the temperature detected by the defrost sensor of the evaporator for the freezer compartment. The refrigerator according to any one of claims 3 to 6,
While the refrigerator compartment is being cooled, the refrigerant leakage state of the refrigeration cycle is determined based on an increasing rate of a temperature detected by a defrost sensor of the evaporator for the refrigerator compartment. The refrigerator according to any one of claims 3 to 7,
During cooling of the refrigerating room, the freezing is based on both the decreasing rate of the detection temperature of the defrost sensor of the evaporator for the freezing room and the increasing rate of the detection temperature of the defrosting sensor of the evaporator for the freezing room. A refrigerator characterized by determining a refrigerant leakage state of a cycle. The refrigerator according to any one of claims 3 to 8,
While the compressor is stopped, the refrigeration is performed under a condition in which the change rate or decrease rate of the temperature detected by the defrost sensor of the evaporator for the freezer is set smaller than when the refrigerant leakage is determined in the operating state. A refrigerator characterized by determining a refrigerant leakage state of a cycle. The refrigerator according to any one of claims 1 to 9,
In the configuration provided with a cooling fan for cooling the compressor,
A refrigerator characterized in that, when the refrigerant leakage state of the refrigeration cycle is determined, when the cooling fan is in a stopped state, the refrigerator is operated. The refrigerator according to claim 10,
The refrigerator is characterized in that the operation of the cooling fan after the refrigerant leakage state determination is stopped after a certain period of time. The refrigerator according to claim 11,
The refrigerator is characterized in that the operation of the cooling fan after the refrigerant leakage state determination is intermittently performed. The refrigerator according to any one of claims 1 to 9,
In a configuration in which a cooling fan for cooling the compressor is not provided,
The refrigerator is characterized in that when the refrigerant leakage state of the refrigeration cycle is determined, the compressor is stopped for a certain period of time. The refrigerator according to any one of claims 3 to 9,
The refrigerator is opened when the switching valve is closed when the refrigerant leakage state of the refrigeration cycle is determined.

Images