JP2002061972A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable, by a simple constitution, an accurate judgement of whether or not a fault occurs in a back flow preventing function of a check valve provided in a refrigerant channel. SOLUTION: A control circuit reads (steps A1 to A4) a refrigerant inlet side temperature T1 and a refrigerant outlet side temperature T2 of an evaporator for a cold storage partition at each predetermined time during a period in which a refrigerating cycle is in a first operation mode (in an operation mode in which a refrigerant supplied from a compressor via a condenser is supplied to the evaporator for the cold storage partition via a capillary tube and then recovered to the compressor), judges the effect that the fault occurs in the back flow preventing function of the check valve when the temperature T2 becomes higher by a predetermined temperature Ts or higher than the temperature T1, and outputs a back flow sensing signal (steps A6 and A7).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refrigerator compartment and a refrigeration compartment having different temperature zones, each having a dedicated evaporator and a cool air circulation fan, and supplying a refrigerant to each dedicated evaporator individually. And a refrigerator capable of setting a section at an arbitrary temperature.

[0002]

2. Description of the Related Art Conventionally, a refrigerator equipped with a dedicated evaporator and a cool air circulation fan in each of a refrigerator compartment (refrigerator compartment, vegetable compartment, etc.) and a freezer compartment (freezer compartment, ice making compartment, etc.) is shown in FIG. One provided with a refrigeration cycle as shown is considered. That is, in FIG. 10, the discharge port of the compressor 1 communicates with the inlet of the three-way solenoid valve 3 via the condenser 2, and one outlet of the three-way solenoid valve 3 is connected to the capillary tube 4, which is a pressure reducing means, The evaporator 5 and the suction pipe 6 communicate with the suction port of the compressor 1. The other outlet of the three-way solenoid valve 3 is provided with a capillary tube 7 as a decompression means, an evaporator 8 for a freezing compartment, an accumulator 9 for temporarily storing excess refrigerant, this accumulator 9 and an evaporator 8 for a freezing compartment. A check valve 10 for preventing a backflow of the refrigerant to the side and a suction pipe 6 are connected to a suction port of the compressor 1.

In this case, the three-way solenoid valve 3 is connected to the compressor 1
From the refrigerant supplied through the condenser 2 to the refrigerator compartment evaporator 5 via the capillary tube 4, the refrigerant flowing into the freezing compartment evaporator 8 via the capillary tube 7, It is configured to be able to switch to any of the fully closed states where the flow is blocked. And
In the refrigeration cycle, by controlling the state of the three-way solenoid valve 3, during the cooling operation of the refrigeration compartment, the refrigerant supplied from the compressor 1 via the condenser 2 is supplied via the capillary tube 4 to the refrigeration compartment. The operation mode is switched to the first operation mode in which the refrigerant is recovered by the compressor 1 after flowing into the evaporator 5, and the refrigerant supplied from the compressor 1 via the condenser 2 is passed through the capillary tube 7 during the cooling operation of the freezing section. Then, the flow is switched to the second operation mode in which the refrigerant is recovered by the compressor 1 via the accumulator 9 and the check valve 10 after flowing into the evaporator 8 for the freezing compartment. In addition, the three-way solenoid valve 3
Is switched to the fully closed state in a state where the respective cooling operations of the refrigeration section and the freezing section are stopped.

[0004]

In the refrigerator provided with the above-described refrigerating cycle, the evaporating temperature of the refrigerant in the refrigerating compartment evaporator 5 during the cooling operation of the refrigerating compartment (in the first operation mode) ( (Evaporation pressure) is higher than the temperature (condensation pressure) of the freezing compartment evaporator 8. For this reason, when the check valve 10 is not provided, a phenomenon occurs in which the refrigerant vaporized in the refrigeration compartment evaporator 5 flows into the refrigeration compartment evaporator 8 via the suction line and recondenses. However, since the check valve 10 is actually provided, the occurrence of the recondensation phenomenon as described above is prevented.

However, in the check valve 10, foreign matter is caught between the valve body and the valve seat and cannot be completely closed, or foreign matter is caught between the valve body and the valve case. In some cases, the movement of the valve body is locked, and in such a case, the backflow prevention function is impaired. When the check valve 10 is in a state in which the check valve 10 is blocked, during the cooling operation of the refrigeration compartment, the vaporized refrigerant flows into the refrigeration compartment evaporator 8 through the check valve 10 and re-condenses and stays there. Therefore, a phenomenon occurs in which the amount of refrigerant flowing in the refrigeration cycle is insufficient. In such a state in which the amount of the circulating refrigerant is insufficient, a serious situation that the cooling of the refrigeration compartment is insufficient is caused, and therefore, it is ensured that the check valve 10 has a failure in the check valve blocking function. It is desirable to prepare a means that can detect the situation, and to take some measures based on the detection result.
However, in the related art, there is no means capable of accurately determining whether or not a failure has occurred in the check valve 10 in the check valve 10 with a simple configuration, and this has been an unsolved problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to determine whether or not a failure has occurred in a check valve blocking function provided in a refrigerant flow path by a simple configuration. An object of the present invention is to provide a refrigerator that can be accurately determined.

[0007]

According to the first aspect of the present invention,
In order to achieve the above object, a dedicated evaporator and a cool air circulation fan are provided in each of a refrigeration section and a refrigeration section having different temperature zones, and supplied from a compressor through a condenser by a valve device for switching a refrigerant flow path. A first operation mode in which the refrigerant to be cooled flows into the evaporator for the refrigerated compartment through the decompression means and then recovered to the compressor, and the refrigerant supplied from the compressor via the condenser through the decompression means In the refrigerator, which is switched to the second operation mode in which the refrigerant is returned to the compressor via a check valve after flowing into the evaporator for the freezing compartment, and the refrigerator is switched to the first operation mode. When the temperature of the refrigerant outlet side of the compartment evaporator is higher than the temperature of the refrigerant inlet side of the evaporator by a predetermined temperature or more, it is determined that a failure has occurred in the check valve blocking function of the check valve. Control circuit It is obtained by a configuration of providing.

[0008] According to the refrigerator having the above-described configuration, in the state where the first operation mode is switched, that is, in the state where the refrigerant flowing into the refrigeration compartment evaporator is recovered by the compressor, the check valve has a backflow prevention function. When a failure occurs in the evaporator, the vaporized refrigerant discharged from the evaporator for the refrigerating compartment flows into the evaporator for the refrigerating compartment via the check valve. In this case, the vaporized refrigerant flowing into the refrigeration compartment evaporator stays as it is after being recondensed there, so the amount of refrigerant flowing through the refrigeration cycle is insufficient, and the amount of refrigerant supplied to the refrigeration compartment evaporator is relatively small. Phenomenon occurs. When such a phenomenon occurs, the difference between the temperature on the refrigerant outlet side of the evaporator for the refrigeration compartment and the temperature on the refrigerant inlet side of the evaporator becomes larger. When such a temperature difference is equal to or higher than a predetermined temperature, that is, when the temperature of the refrigerant outlet side of the evaporator for the refrigeration compartment is higher than the temperature of the refrigerant inlet side of the evaporator by a predetermined temperature or more, The control circuit determines that a failure has occurred in the check valve blocking function of the check valve. Therefore,
Whether the check valve provided in the refrigerant flow path has a failure in the backflow prevention function or not is determined by merely providing a means for detecting a temperature difference between the refrigerant outlet side and the refrigerant inlet side of the evaporator for the refrigeration compartment. With the simple configuration described above, accurate judgment can be made.

According to a second aspect of the present invention, in order to achieve the above object, a dedicated evaporator and a cool air circulation fan are provided in each of a refrigeration section and a refrigeration section having different temperature zones,
A first operation mode in which a refrigerant supplied from a compressor via a condenser is caused to flow into the refrigeration compartment evaporator via a decompression means by a valve device for switching a refrigerant flow path, and then recovered by the compressor. The operation mode is switched to the second operation mode in which the refrigerant supplied from the compressor through the condenser flows into the refrigeration compartment evaporator through the decompression means, and then is recovered to the compressor through a check valve. In the refrigerator, when the mode is switched to the first operation mode, when the temperature of the evaporator for the freezing compartment becomes higher than a normal temperature, a failure occurs in the check valve blocking function of the check valve. Is provided with a control circuit for making the determination.

[0010] In the refrigerator configured as described above,
In the state switched to the first operation mode, that is, in the state where the refrigerant flowing into the refrigeration compartment evaporator is recovered by the compressor, if a failure occurs in the check valve blocking function of the check valve, the refrigeration compartment The vaporized refrigerant discharged from the evaporator for use flows into the evaporator for freezing compartment via the check valve. In this case, since the vaporized refrigerant having a relatively high temperature flows into the evaporator for the freezing compartment and re-condenses, a phenomenon occurs in which the temperature of the evaporator rises. As a result, the temperature of the refrigerating compartment evaporator is higher than usual, and in such a state, the control circuit determines that a failure has occurred in the check valve blocking function of the check valve. Become like Therefore, whether or not a failure has occurred in the check valve blocking function of the check valve provided in the refrigerant flow path is accurately determined by a simple configuration using only a means for detecting the temperature of the freezing compartment evaporator. It becomes possible.

[0011] In the case of adopting such a configuration according to the second aspect, as described in the third aspect, the control circuit is switched to the first operation mode and the evaporator for the refrigeration compartment is switched to the first operation mode. When the state where the temperature is higher than the temperature of the refrigeration section continues for a predetermined time or more, it may be configured that it is determined that a failure has occurred in the check valve blocking function of the check valve.

[0012] According to this configuration, in the state switched to the first operation mode, if a failure occurs in the check valve blocking function of the check valve, the vaporized refrigerant having a relatively high temperature is supplied to the evaporator for the refrigeration compartment. , And re-condenses, the temperature of the freezing compartment evaporator becomes higher than the temperature of the freezing compartment. In this case, the control circuit determines that a failure has occurred in the check valve blocking function of the check valve only when the state in which the temperature of the freezing compartment evaporator is higher than the temperature of the freezing compartment continues for a predetermined time or more. Become. As a result, even in a case where the state in which the temperature of the evaporator is higher than the temperature of the refrigeration compartment momentarily occurs during the period in which the supply of the refrigerant to the refrigeration compartment evaporator is stopped during the normal operation, this is prevented. This eliminates the risk of erroneously determining that a failure has occurred in the backflow prevention function of the valve, and improves the reliability of the determination result.

[0013] In the case of adopting the constitution of the second or third aspect, as described in the fourth aspect, the refrigerant passage between the refrigerant outlet of the evaporator for the freezing compartment and the check valve is provided. An accumulator is provided, and the accumulator is provided with a defrosting operation temperature sensor for controlling a defrosting operation of the refrigeration compartment evaporator, and a detection output of the defrosting operation temperature sensor is supplied to the refrigeration compartment evaporator. May be used as a signal indicating the temperature of the radiator.

According to this configuration, the temperature of the accumulator fluctuates with substantially the same tendency as the temperature of the evaporator for the freezing compartment. Therefore, the temperature sensor for the defrosting operation provided in the accumulator is used for the evaporator for the freezing compartment. Even if it is also used as a means for detecting the temperature of the vessel, there is no problem at all, and as a result, the overall configuration can be prevented from becoming complicated.

According to a fifth aspect of the present invention, when the control circuit performs an operation of determining that a failure has occurred in the check valve blocking function of the check valve, the mode switching operation by the valve device is forcibly performed. It can be configured to execute control to be repeatedly repeated.

According to this configuration, when the control circuit determines that a failure has occurred in the check valve blocking function of the check valve, the mode switching operation by the valve device, that is, the switching from the compressor to the condenser is performed. The state where the refrigerant supplied via the refrigerant flows into the refrigeration compartment evaporator and then is recovered by the compressor, and the state where the refrigerant supplied from the compressor via the condenser flows into the refrigeration compartment evaporator and is recovered by the compressor Since the operation for switching the state of the check valve is forcibly repeated, the refrigerant flows in the forward and reverse directions with respect to the check valve in which the failure has occurred. Accordingly, if the failure of the check valve blocking function of the check valve is caused by a foreign matter caught between the valve body and the valve seat or between the valve body and the valve case, the foreign matter is This increases the probability of being removed, which is beneficial in improving the cooling performance of the refrigerator.

In this case, as described in claim 6, it is possible to provide a configuration including storage means for storing the number of executions of the mode switching operation by the valve device by the control circuit. According to this configuration, it is possible to easily know the history of the number of times the mode switching operation has been performed in response to the occurrence of a failure in the check valve. The cause can be specified accurately and easily.

According to a seventh aspect of the present invention, when the control circuit performs an operation of judging that a failure has occurred in the check valve blocking function of the check valve, the rotation speed of the cooling air circulation fan for the refrigerating compartment is increased. It is possible to adopt a configuration in which the control for maintaining the lowered state is executed.

According to this configuration, if a failure occurs in the check valve blocking function of the check valve, the number of rotations of the cooling air circulation fan for the cooling compartment is reduced, and as a result, the amount of heat exchange in the evaporator for the cooling compartment is reduced. And its evaporation temperature decreases. For this reason, after a failure occurs in the check valve blocking function of the check valve, the vaporized refrigerant flowing out of the refrigeration section evaporator flows into the refrigeration section evaporator via the check valve and recondenses. Even if the phenomenon that the refrigerant stays as it is, that is, the phenomenon that the amount of refrigerant flowing in the refrigeration cycle runs short, the efficiency of the refrigeration cycle decreases, but the cooling operation of the refrigeration section can be continued, and the refrigeration section It is possible to prevent a situation in which the cooling of the heater becomes insufficient as much as possible.

In the case where the control for maintaining the rotation speed of the cooling air circulation fan for the refrigeration compartment at a reduced state is performed as described above, the control circuit controls the holding control for the refrigeration compartment. It is possible to adopt a configuration in which it is released when the defrosting operation of the evaporator is completed. In this case, in the state where the defrosting operation of the freezing compartment evaporator has been completed, a large amount of refrigerant flows into the freezing compartment evaporator when the operation mode is switched to the second operation mode thereafter, and the check operation is stopped. Foreign matter between the valve body and the valve seat of the valve or between the valve body and the valve case is easily removed. For this reason, after the completion of the defrosting operation of the evaporator for the freezing compartment, there is a high probability that the control for maintaining the rotation speed of the cooling air circulation fan for the refrigerating compartment at a reduced state as described above becomes unnecessary. Yes, so
By performing the release control as described above, it is possible to quickly return to the normal operation state.

[0021] In the case of adopting the structure of claim 7 or 8, as described in claim 9, at least the defrosting operation of the evaporator for the freezing compartment is performed at a preset cycle, and When the load of the evaporator is small, the defrosting operation cycle is configured to be extended, and when the control circuit is performing control to maintain the rotation speed of the cooling air circulation fan for the refrigeration compartment at a reduced speed. The defrosting operation cycle can be configured not to be extended.

According to this configuration, even if the load on the evaporator is small, the cycle of the defrosting operation is not extended. The state in which a large amount of refrigerant flows into the evaporator is performed at a relatively early cycle, and it is possible to contribute to the above-described foreign matter removing action and the early return to the normal operation state accompanying the action.

In this case, as described in claim 10,
A configuration may be provided that includes a storage unit that stores the number of times the control circuit has executed the control of maintaining the rotation speed of the refrigeration compartment cool air circulation fan at a reduced speed.
According to this configuration, it is possible to easily know the history of the number of times the number of rotations of the cooling air circulation fan for the refrigeration compartment has been reduced in response to the occurrence of a failure in the check valve. , The cause of the defect can be specified accurately and easily.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIGS. 1 to 5 show a first embodiment of the present invention, which will be described below. FIG. 3 is a schematic longitudinal sectional view of the refrigerator according to the present embodiment. In FIG. 3, the inside of the refrigerator main body 11 configured as a heat insulating box is vertically divided into a refrigeration section 13 and a freezing section 14 having different temperature zones by a heat insulating partition wall 12. The refrigeration compartment 13 has a refrigeration compartment 13a vertically divided by a partition plate 15.
And a vegetable compartment 13b. In addition, frozen section 1
4 is provided with a freezing case 14a constituting a freezing room and an ice making unit 14b. In addition, the partition plate 15
At a predetermined portion (for example, a portion near the rear end),
A cool air circulation port (not shown) is formed in a state in which communication is established between 3a and the vegetable compartment 13b. The refrigerator body 11
On the front side, doors 11a and 11b for the refrigerator compartment 13a and the vegetable compartment 13b of the refrigerator compartment 13 and a door 11c for the freezing compartment 14 are provided.

A first evaporator chamber 17 partitioned by a plastic plate-like cover member 16 is formed on the back of the vegetable chamber 13b.
A cool air circulation fan 18, a refrigerating compartment evaporator 19, a defrost heater 20, and a defrost water receiving gutter 21 are arranged as shown. The cover member 16 has a suction port (not shown) for sucking air from inside the vegetable compartment 13b. Further, a ventilation duct 22 whose lower end communicates with the first evaporator chamber 17 is provided from the back to the ceiling of the refrigerator compartment 13a.
2, a plurality of outlets (not shown) for supplying cool air into the refrigerator compartment 13a are formed in multiple stages.

Thus, when the cool air circulation fan 18 is in operation, the cool air generated by the evaporator 19 for the refrigeration compartment is supplied from the first evaporator chamber 17 to the refrigeration chamber 13a through the air duct 22. And flows into the vegetable compartment 13b through a not-shown cool air circulation port formed in the partition plate 15, and is further returned into the first evaporator chamber 17 through a not-shown suction port formed in the cover member 16.
Thereby, the cooling operation of the refrigeration section 13 is performed.

On the other hand, a second evaporator chamber 24 defined by a plastic plate-like cover member 23 is formed on the back surface of the freezing section 14, and a cool air circulation is formed in the second evaporator chamber 24. A fan 25, a freezing compartment evaporator 26, a defrost heater 27, and a defrost water receiving gutter 28 are arranged as shown. An outlet (unsigned) for supplying cool air to the ice making unit 14b in the freezing compartment 14 is formed at an upper portion of the cover member 23, and a refrigeration port is provided at a lower portion of the cover member 23. A suction port (not numbered) for sucking air from inside the compartment 14 is formed.

Thus, when the cool air circulation fan 25 is in operation, the cool air generated in the freezing compartment evaporator 26 is supplied from the second evaporator chamber 24 to the ice making section in the freezing compartment 14 through an outlet (no symbol). After being supplied to the unit 14b, the second evaporator chamber 24
The cooling operation of the freezing section 14 is performed.

A machine room 29 is formed at the bottom of the refrigerator main body 11, and an electric motor (FIG.
30M) as a drive source.
And an evaporating dish 31 for receiving defrost water. The compressor 30 is for driving the refrigeration cycle shown in FIG.

In FIG. 4, the refrigerating cycle includes a condenser 32, a three-way solenoid valve 33 (in addition to the evaporator 19 for the refrigerating compartment, the evaporator 26 for the refrigerating compartment, and the compressor 30). Equivalent), capillary tubes 19a and 26a as decompression means for each of the evaporators 19 and 26, an accumulator 34 for temporarily storing excess refrigerant,
The configuration includes a check valve 35 for preventing the backflow of the refrigerant, and the like. In this case, the discharge port of the compressor 30 communicates with the inlet of the three-way solenoid valve 33 via the condenser 32, and one outlet of the three-way solenoid valve 33 is connected to the capillary tube 19.
a, it is connected to the suction port of the compressor 30 via the refrigerating compartment evaporator 19 and the suction pipe 36. The other outlet of the three-way solenoid valve 33 is connected to the capillary tube 26.
a, it is connected to the suction port of the compressor 30 via the evaporator 26 for the freezing compartment, the accumulator 34, the check valve 35, and the suction pipe 36.

In this case, the three-way solenoid valve 33 is in a state where the refrigerant supplied from the compressor 30 via the condenser 32 flows into the refrigeration compartment evaporator 19 via the capillary tube 19a, and the refrigerant is supplied to the capillary tube 26a. , And into a completely closed state in which the flow of the refrigerant is blocked.

In the refrigeration cycle, by controlling the state of the three-way solenoid valve 33, the refrigerant supplied from the compressor 30 via the condenser 32 during the cooling operation of the refrigeration section 13 is supplied to the capillary tube 19a. The operation mode is switched to the first operation mode in which the refrigerant flows into the refrigerating compartment evaporator 19 via the refrigeration compartment 19, and is recovered by the compressor 30. In the cooling operation of the freezing compartment 14, the refrigerant is supplied from the compressor 30 via the condenser 32. After the refrigerant flows into the freezing compartment evaporator 26 via the capillary tube 26a, the accumulator 34
The operation mode is switched to the second operation mode in which the compressor 30 is recovered via the check valve 35. The three-way solenoid valve 33 is switched to the fully closed state in a state where the cooling operation of the refrigeration section 13 and the freezing section 14 is stopped.

FIG. 2 schematically shows the electric configuration of the refrigerator according to the present embodiment by combining functional blocks. That is, in FIG. 2, the refrigeration compartment temperature sensor 37 and the freezing compartment temperature sensor 38 are arranged so as to detect the temperatures Tr and Tf in the refrigeration compartment 13 and the freezing compartment 14, respectively. The configuration is such that it is provided to an input port of a control circuit 39 mainly composed of a microcomputer.

The evaporator temperature sensors 40 and 41 for the refrigerating compartment are arranged to detect the temperature T1 on the refrigerant inlet side and the temperature T2 on the refrigerant outlet side of the evaporator 19 for the refrigerating compartment, respectively. Control circuit 39
To the input port.

The refrigerating compartment evaporator temperature sensor 42 is arranged to detect the temperature T 3 of the refrigerating compartment evaporator 26, and is configured to supply the temperature detection signal to the input port of the control circuit 39. I have. Further, the defrosting operation temperature sensor 43 is arranged to detect the temperature T4 of the accumulator 34, and is configured to supply the temperature detection signal to the input port of the control circuit 39. The temperature T4 of the accumulator 34 depends on the temperature of the freezing compartment evaporator 26.
Therefore, by using the temperature sensor 43 for the defrosting operation provided in the accumulator 34 as a means for detecting the temperature T3 of the freezing compartment evaporator 26, the refrigeration is performed. It is also possible to omit the compartment evaporator temperature sensor 42.

The output port of the control circuit 39 includes the compressor 3
An inverter circuit 44 for driving the electric motor 30M at a variable speed, a cooling fan provided for cooling the three-way solenoid valve 33, the cool air circulation fans 18 and 25, the defrost heaters 20 and 27, and the compressor 30. A drive circuit 46 for driving each of the drive circuits 45 is connected.

The flowchart (FIG. 1) shows a program (subroutine) of a part related to the gist of the present invention in the contents of control by the control circuit 39.
Hereinafter, this will be described together with related operations. That is, in FIG. 1, the control circuit 39 first determines whether or not the refrigeration cycle is in the first operation mode (step A1). If “NO”, the process returns to the main routine as it is. In the case of "YES", it is determined whether or not the end condition of the first operation mode is satisfied (step A).
2).

The end condition of the first operation mode is, for example,
This is established when the temperature Tr in the refrigerating compartment 13 indicated by the temperature detection signal from the refrigerating compartment temperature sensor 37 has become equal to or lower than a predetermined set temperature. When the temperature Tr has been established, the process returns to the main routine. On the other hand, in a state where the end condition of the first operation mode is not satisfied, it is determined whether or not a predetermined time (for example, several minutes) has elapsed (step A3). The period during which the determination in step A3 is "NO" returns to step A2, but when the determination is "YES", the temperature indicated by the temperature detection signals from the refrigerator compartment evaporator temperature sensors 40 and 41, that is,
The temperature T1 on the refrigerant inlet side and the temperature T2 on the refrigerant outlet side of the refrigerator compartment evaporator 19 are read (step A4).

Then, a temperature difference ΔT (= T2−T1) between the read temperatures T1 and T2 is calculated (step A).
5) It is determined whether the temperature difference ΔT has become equal to or higher than a predetermined temperature Ts (step A6). Therefore, when the temperature T2 on the refrigerant outlet side of the evaporator 19 for the refrigeration compartment is higher than the temperature T1 on the refrigerant inlet side of the evaporator 19 by the predetermined temperature Ts or more, "YES" is determined in step A6. However, in other states, "NO" is determined in step A6.

Then, in step A6, "N
When it is determined to be "O", the process returns to step A2, but "Y"
When it is determined to be "ES", a backflow detection signal is output (step A7). In short, the control circuit 39 determines that the temperature T2 on the refrigerant outlet side of the refrigeration compartment evaporator 19 is higher than the temperature T1 on the refrigerant inlet side of the evaporator 19 when the refrigeration cycle is switched to the first operation mode. When the temperature becomes higher than the predetermined temperature Ts, it is determined that a failure has occurred in the backflow prevention function of the check valve 35, and a backflow detection signal is output.

Here, the state in which the refrigeration cycle is switched to the first operation mode, that is, the refrigeration compartment evaporator 19
When the check valve 35 has a failure in the check valve 35 in a state where the refrigerant flowing into the compressor 30 is recovered by the compressor 30, the vaporized refrigerant discharged from the evaporator 19 for the refrigerating compartment is discharged to the check valve 3.
5 and accumulator 34 and evaporator 2 for freezing compartment
6 will start flowing. In this case, the accumulator 3
The vaporized refrigerant flowing into the evaporator 4 and the freezing compartment 26 is:
Therefore, since the refrigerant stays as it is after being recondensed, the amount of the refrigerant flowing through the refrigeration cycle is insufficient, and the evaporator 19 for the refrigeration compartment 19
A phenomenon occurs in which the amount of the refrigerant supplied to the heater becomes relatively small. As a result, it is considered that a phenomenon occurs in which the difference ΔT between the temperature T2 at the refrigerant outlet side of the evaporator 19 for the refrigeration compartment and the temperature T1 at the refrigerant inlet side of the evaporator 19 increases.

In order to verify the occurrence of the phenomenon that the temperature difference ΔT increases, the inventors of the present invention applied the check valve 35 in a state where there is no leakage (a state where the backflow prevention function is normal). The refrigerant inlet side temperature T1 and the refrigerant outlet side temperature T2 of the refrigeration compartment evaporator 19 at the time, and the temperatures T1 and T2 at the time when the state where the check valve 35 has a leak is artificially created. An experiment for actual measurement was performed. FIG. 5 shows the temperature measurement results. From FIG. 5, it can be seen that when there is a leak in the check valve 35, the temperature difference ΔT between the refrigerant inlet side temperature T1 and the refrigerant outlet side temperature T2 of the refrigerating compartment evaporator 19 tends to increase.

Therefore, when the temperature difference ΔT as described above becomes equal to or higher than the predetermined temperature Ts (that is, the refrigeration compartment evaporator 1).
9 when the temperature T2 on the refrigerant outlet side of the evaporator 19 becomes higher than the temperature T1 on the refrigerant inlet side of the evaporator 19 by a predetermined temperature Ts or more. Can be used as a signal that accurately indicates that a failure has occurred.

After executing the output step A7 of the backflow detection signal, the control circuit 39 increments the signal output frequency N (the initial value is zero) by "1" (step A8).
After this, the signal output frequency N becomes a predetermined number (for example, about several times).
It is determined whether or not the above has been achieved (step A9). If the determination is "NO", the process returns to step A2.
When the judgment is "YES", the mode switching processing routine A10 is executed.

In this routine A10, the three-way solenoid valve 33
By performing the switching operation described above, the mode switching operation of forcibly switching to the second operation mode for a predetermined time and then returning to the first operation mode is performed a predetermined number of times (even once). Such a mode switching operation, that is, a state in which the refrigerant supplied from the compressor 30 via the condenser 32 flows into the refrigeration compartment evaporator 19 and is recovered by the compressor 30 (first operation mode), The refrigerant supplied from the compressor 30 via the condenser 32 is supplied to the refrigeration compartment evaporator 26.
The operation of switching the state (second operation mode) to be recovered by the compressor 30 after flowing into the compressor is forcibly repeated a predetermined number of times, so that the refrigerant flows to the check valve 35 in the forward and reverse directions. Become. Thereby, if the failure of the check valve 35 in the backflow prevention function is caused by a foreign substance caught between the valve element and the valve seat or between the valve element and the valve case, the foreign substance Is more likely to be removed.

After execution of the mode switching processing routine A10, the control circuit 39 sends the above-mentioned mode to, for example, a nonvolatile memory (not shown: corresponding to the storage means in the present invention) provided therein. After executing step A11 of adding and storing the number of executions of the switching operation, step A2 is executed.
Return to

In short, in the control circuit 39,
During the period when the refrigeration cycle is in the first operation mode, the temperature T1 on the refrigerant inlet side of the evaporator 19 for the refrigeration compartment at regular intervals.
And the refrigerant outlet side temperature T2 is read, and the refrigerant outlet side temperature T2 is set to a predetermined temperature T from the refrigerant inlet side temperature T1.
When it becomes higher than s, it is determined that a failure has occurred in the backflow prevention function of the check valve 35, and a backflow detection signal is output.

The backflow detection signal output in this manner can be used as a signal that accurately indicates that a failure has occurred in the backflow prevention function of the check valve 35 as described above. Therefore, the temperature difference between the refrigerant outlet side and the refrigerant inlet side of the refrigeration compartment evaporator 19 is detected by determining whether or not the check valve 35 provided in the refrigerant flow path has a failure in the backflow prevention function. Precise determination can be made by a simple configuration in which only means (refrigerator compartment evaporator temperature sensors 40 and 41) are provided (that is, a configuration in which one originally needs only two refrigerating compartment evaporator temperature sensors). It becomes possible.

When the determination that the check valve 35 has failed in the check valve 35 has been performed a predetermined number of times in succession, the mode switching operation of the three-way solenoid valve 33 is forcibly performed a predetermined number of times. The control for repetition is executed, and the refrigerant flows to the check valve 35 in the forward and reverse directions. As a result,
As described above, in the case where the failure of the check valve blocking function of the check valve 35 is caused by a foreign matter caught between the valve body and the valve seat or between the valve body and the valve case, This increases the probability that the foreign matter is removed, which is useful for improving the cooling performance of the refrigerator.

In this case, since the number of executions of the mode switching operation as described above is stored in the non-volatile memory in the control circuit 39, the mode is set according to the occurrence of a failure in the check valve 35. The history of the number of times the switching operation has been performed can be easily known. Therefore, when the refrigerator is repaired later due to poor cooling or the like, the cause of the failure can be accurately and easily specified.

(Second Embodiment) FIGS. 6 to 8 show a second embodiment of the present invention having the same effects as those of the first embodiment. Only different parts will be described. FIG. 7 schematically shows the electric configuration of the refrigerator in this embodiment by combining functional blocks.
In this embodiment, the temperature T at a predetermined portion (for example, the refrigerant outlet side) of the refrigerator compartment evaporator 19 is replaced with the refrigerator compartment evaporator temperature sensors 40 and 41 in the first embodiment.
A configuration is provided in which a refrigerator compartment evaporator temperature sensor 47 for detecting 0 is provided.

In the flowchart of FIG.
3 shows a program (subroutine) of a part related to the gist of the present invention among control contents according to the present invention. Hereinafter, only a part different from the flowchart (FIG. 1) in the first embodiment will be described. That is, in FIG.
When the control circuit 39 determines “YES” in step A3 (when a predetermined time has elapsed while the first operating mode end condition is not satisfied), the freezing compartment temperature sensor 38 and the freezing compartment temperature The temperature indicated by the temperature detection signal from the evaporator temperature sensor 42, that is, the temperature Tf of the freezing compartment 14 and the temperature T3 of the freezing compartment evaporator 26 are read (step A4 ').

Next, by comparing the read temperatures Tf and T3, it is determined whether or not the relationship of T3> Tf is satisfied (step A5 '). Here, when it is determined to be “NO” (when T3 ≦ Tf), the process returns to step A2, but when it is determined to be “YES” (T
3> Tf), it is determined whether a predetermined time (for example, about several minutes) has elapsed (step A).
6 '). If "NO" is determined in step A6 ', the process returns to step A5'. If "YES" is determined, the control in and after step A7 for outputting a backflow detection signal is executed.

In short, when the control circuit 39 is switched to the first operation mode and the temperature T3 of the freezing compartment evaporator 26 is higher than the temperature Tf of the freezing compartment 14 for a predetermined time or more, This is to determine that a failure has occurred in the backflow prevention function of the check valve 35 and to output a backflow detection signal.

Here, the state in which the refrigeration cycle is switched to the first operation mode, that is, the refrigeration compartment evaporator 19
If the check valve 35 has a failure in the check valve 35 in a state where the refrigerant flowing into the compressor 30 is recovered by the compressor 30, the refrigerant having a relatively high temperature is cooled by the evaporator 34 via the check valve 35. And flows into the refrigerating compartment evaporator 26 to be recondensed, so that the temperature T3 of the refrigerating compartment evaporator 26 is higher than the normal temperature, specifically, the temperature T3 is higher than the temperature Tf of the refrigerating compartment 14. It is considered that there may be a case.

As described above, the temperature T of the freezing compartment evaporator 26
In order to verify the occurrence of a phenomenon in which the temperature of the non-return section 3 becomes higher than the temperature Tf of the freezing section 14, the inventors of the present patent application determined that the check valve 35 had no leakage (a state in which the backflow prevention function is normal). ), The temperature T3 of the freezing compartment evaporator 26 and the temperature Tf of the freezing compartment 14, and the respective temperatures T when the check valve 35 is artificially created to have a leak.
An experiment for actually measuring 3 and Tf was performed. FIG. 8 shows the temperature measurement results. From this FIG.
It can be seen that when the check valve 35 has a leak, the state in which the temperature T3 of the freezing compartment evaporator 26 has become higher than the temperature Tf of the freezing compartment 14 continues for a relatively long time.

Therefore, as described above, the freezing compartment evaporator 2
6 and the temperature Tf of the freezing section 14 are T3> T.
The backflow detection signal output when the state of f has continued for a predetermined time or more can be used as a signal that accurately indicates that a failure has occurred in the backflow prevention function of the check valve 35. That is, also in the present embodiment, whether the check valve 35 provided in the refrigerant flow path has a failure in the backflow prevention function is determined by the refrigeration compartment temperature sensor 38 and the refrigeration compartment evaporator which are originally required. A simple configuration using the temperature sensor 42 enables accurate determination.

In this embodiment, the evaporator 2 for the freezing compartment is used.
The backflow detection signal is output only when the temperature T of No. 6 is higher than the temperature Tf of the freezing section 14 for a predetermined time or more. As a result, when the supply of the refrigerant to the freezing compartment evaporator 26 is stopped during the normal operation, a state in which the temperature T3 of the evaporator 26 is higher than the temperature Tf of the freezing compartment 14 instantaneously occurs ( "No leakage" in Fig. 8
In this case, there is no possibility of erroneously determining that a failure has occurred in the check valve blocking function of the check valve 35, and the reliability of the determination result is improved.

(Other Embodiments) The present invention is not limited to the above-described embodiment, but can be modified or expanded as follows. In the second embodiment, the freezing compartment evaporator temperature sensor 42 is provided to detect the temperature T3 of the freezing compartment evaporator 26.
4 has a tendency to fluctuate with the same tendency as the temperature T3 of the freezing compartment evaporator 26, so that the defrosting operation temperature sensor 43 provided in the accumulator 34 is connected to the freezing compartment evaporator 2.
By also serving as the means for detecting the temperature T3 of 6, the refrigeration compartment evaporator temperature sensor 42 can be omitted. With such a configuration, it is possible to prevent the overall configuration from becoming complicated.

FIG. 9 shows the temperature T4 of the accumulator 34 and the temperature Tf of the refrigerating compartment 14 when there is no leak in the check valve 35 (the state in which the backflow preventing function is normal). The results of actual measurement of the temperatures T4 and Tf when a certain state was artificially created are shown. From FIG. 9, it can be seen that when the check valve 35 has a leak, the temperature T4 of the accumulator 34 is lower than the temperature of the refrigerating compartment 1.
4, it can be seen that the phenomenon that the temperature becomes higher than the temperature Tf continues for a relatively long time. Accordingly, by using the temperature sensor 43 for the defrosting operation provided on the accumulator 34 as a means for detecting the temperature T3 of the evaporator 26 for the freezing compartment as described above, the evaporator temperature sensor 42 for the freezing compartment is omitted. Even in the case of the configuration, the same operation and effect as in the second embodiment can be expected.

In each of the above embodiments, when the number N of times of output of the backflow detection signal exceeds a predetermined number, the switching operation (mode switching operation) of the three-way solenoid valve 33 is performed, whereby the three-way solenoid valve 33 is caught by the check valve 35. Although the configuration is such that an attempt is made to remove foreign matter, for example, when the number of outputs N of the backflow detection signal is equal to or more than a predetermined number (the determination operation that the failure has occurred in the backflow prevention function of the check valve 35 is continuously performed for a predetermined number of times). ), The control for maintaining the rotation speed of the cool air circulation fan 18 for the refrigeration compartment 13 at a reduced level can be executed.

According to this configuration, when the check valve 35 has a failure in the backflow prevention function, the number of rotations of the cool air circulation fan 18 for the refrigeration compartment 13 is reduced, and as a result, the evaporator 19 for the refrigeration compartment is provided. , The amount of heat exchange becomes small, and the evaporating temperature becomes low. For this reason, the vaporized refrigerant that has flowed out of the refrigeration compartment evaporator 19 flows into the refrigeration compartment evaporator 26 via the check valve 35 due to the failure of the check valve 35 in the backflow prevention function. Even if the phenomenon that the refrigerant stays as it is after the recondensation, that is, the phenomenon that the amount of refrigerant flowing in the refrigeration cycle runs short, occurs, although the efficiency of the refrigeration cycle is reduced, the cooling operation of the refrigeration compartment 13 can be continued. In other words, the situation where the cooling of the refrigerated compartment 13 becomes insufficient can be prevented as much as possible.

In the case where the control for keeping the rotation speed of the cool air circulating fan 18 for the refrigeration compartment 13 at a reduced state is performed, the control circuit 39 controls the keeping control by the control of the evaporator 26 for the refrigeration compartment. It is possible to adopt a configuration in which it is released when the defrosting operation is completed. In this case, the freezing compartment evaporator 2
After the defrosting operation of No. 6 has been completed, the second
When the operation mode is switched to the operation mode, a large amount of refrigerant flows into the freezing compartment evaporator 26, and the check valve 35
Foreign matter between the valve element and the valve seat or between the valve element and the valve case is easily removed. Therefore, after the defrosting operation of the freezing compartment evaporator 26 is completed, there is a high probability that the control for maintaining the rotation speed of the cool air circulation fan 18 for the refrigerating compartment 13 at a reduced state as described above becomes unnecessary. Therefore, by performing the release control as described above,
It is possible to quickly return to the normal operation state.

Further, in this case, at least the defrosting operation of the evaporator 26 for the freezing compartment is performed at a preset cycle, and the defrosting operation cycle is extended when the load on the evaporator 26 is small. And the control circuit 3
When the control for maintaining the rotation speed of the cooling air circulation fan 18 for the refrigeration compartment 13 at a low speed is executed, the defrosting operation cycle may not be extended.

According to this structure, the freezing compartment evaporator 26
The defrosting operation cycle is not extended even when the load of the defrosting operation is small, so that a large amount of refrigerant flows into the refrigeration compartment evaporator 26 when the operation mode is switched to the second operation mode after the end of the defrosting operation. Is performed at a relatively early cycle, and it is possible to contribute to the above-described foreign matter removing action and the early return to the normal operation state accompanying the action.

Of course, as described above, the number of times the control for keeping the rotation speed of the cool air circulation fan 18 for the refrigeration compartment 13 at a reduced state is executed is determined by the non-volatile memory (storage) provided in the control circuit 39. In such a configuration, the cool air circulation fan 18 for the refrigeration compartment 13 may be used in response to the failure of the check valve 35.
Since the history of the number of rotations of the refrigerator can be easily known, when repairing the refrigerator due to poor cooling or the like, the cause of the failure can be specified accurately and easily.

[0067]

According to the present invention, as is apparent from the above description, the refrigerant supplied from the compressor through the condenser is evaporated by the refrigerant passage switching valve device through the decompression means through the decompression means. First to be recovered by the compressor after flowing into the compressor
And a second operation mode in which the refrigerant supplied from the compressor via the condenser flows into the refrigeration compartment evaporator via the decompression means, and then is recovered to the compressor via the check valve. In the refrigerator that can be switched between (i) and (ii), it is only necessary to provide a means for detecting whether or not a failure has occurred in the check valve blocking function of the check valve and detecting the temperature difference between the refrigerant outlet side and the refrigerant inlet side of the evaporator for the refrigeration compartment. Or the simple configuration using only the means for detecting the temperature of the evaporator for the freezing compartment has an advantageous effect that accurate determination can be made.

[Brief description of the drawings]

FIG. 1 is a flowchart showing control contents according to a first embodiment of the present invention.

FIG. 2 is a functional block diagram schematically showing an electric configuration of the refrigerator.

FIG. 3 is a schematic longitudinal sectional view of a refrigerator.

FIG. 4 is a schematic piping diagram of a refrigeration cycle.

FIG. 5 is a characteristic diagram showing temperature measurement results.

FIG. 6 is a view corresponding to FIG. 1, showing a second embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 2;

FIG. 8 is a diagram corresponding to FIG. 5;

FIG. 9 is a diagram corresponding to FIG. 5 for explaining a modification of the present invention.

FIG. 10 is a diagram corresponding to FIG. 4 for explaining a conventional configuration example.

[Explanation of symbols]

11 is a refrigerator body, 13 is a refrigerated compartment, 14 is a frozen compartment,
18 is a cool air circulation fan, 19 is an evaporator for refrigerated compartment, 19
a is a capillary tube (decompression means), 25 is a cool air circulation fan, 26 is an evaporator for a freezing compartment, 26a is a capillary tube (decompression means), 30 is a compressor, 32 is a condenser,
33 is a three-way solenoid valve (valve device), 34 is an accumulator,
35 is a check valve, 37 is a refrigerator compartment temperature sensor, 38 is a freezing compartment temperature sensor, 39 is a control circuit, 40 and 41 are refrigerator compartment evaporator temperature sensors, 42 is a freezer compartment evaporator temperature sensor, and 43 is a filter. The temperature sensor for frost operation, 47 indicates an evaporator temperature sensor for the refrigerated compartment.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3L045 AA02 BA01 CA02 DA02 LA14 MA04 MA16 NA03 NA22 PA01 PA02 PA03 PA04 PA05 3L046 AA02 AA03 BA01 CA06 FB01 JA12 KA04 LA19 MA01 MA02 MA03 MA04 MA05

Claims (10)

[Claims] 1. A refrigeration section and a refrigeration section each having a different temperature zone are provided with a dedicated evaporator and a cool air circulation fan, respectively, and a refrigerant supplied from a compressor via a condenser by a refrigerant flow switching valve device. A first operation mode in which the refrigerant flows into the refrigerated compartment evaporator via the decompression means and then is recovered by the compressor, and the refrigerant supplied from the compressor via the condenser is subjected to the refrigeration through the decompression means. In the refrigerator, which is switched to a second operation mode in which the refrigerant is recovered to the compressor through a check valve after flowing into the compartment evaporator, the evaporator for the refrigeration compartment is switched in the first operation mode. When the temperature of the refrigerant outlet side of the evaporator is higher than the temperature of the refrigerant inlet side of the evaporator by a predetermined temperature or more, a control circuit that determines that a failure has occurred in the check valve blocking function of the check valve is provided. Established Refrigerator and features. 2. A refrigeration section and a refrigeration section each having a different temperature zone are provided with a dedicated evaporator and a cool air circulation fan, respectively, and a refrigerant supplied from a compressor via a condenser by a refrigerant flow switching valve device. A first operation mode in which the refrigerant flows into the refrigerated compartment evaporator via the decompression means and then is recovered by the compressor, and the refrigerant supplied from the compressor via the condenser is subjected to the refrigeration through the decompression means. In the refrigerator, which is switched to a second operation mode in which the refrigerant is recovered to the compressor through a check valve after flowing into the compartment evaporator, the evaporator for the refrigeration compartment is switched to the first operation mode. A refrigerator provided with a control circuit for judging that a failure has occurred in the check valve blocking function of the check valve when the temperature of the vessel becomes higher than the normal temperature. 3. The refrigerator according to claim 2, wherein the control circuit determines that a state in which the temperature of the evaporator for the refrigerating compartment is higher than the temperature of the refrigerating compartment in a state switched to the first operation mode. A refrigerator characterized by determining that a failure has occurred in the check valve blocking function of the check valve when the check valve has continued for a period of time or longer. 4. The refrigerator according to claim 2, wherein an accumulator is arranged in a refrigerant passage between the refrigerant outlet of the evaporator for the freezing compartment and the check valve, and the accumulator is provided in the accumulator. A defrosting operation temperature sensor for controlling the defrosting operation of the evaporator is provided, and the detection output of the defrosting operation temperature sensor is used as a signal indicating the temperature of the freezing compartment evaporator. Refrigerator to feature. 5. The refrigerator according to any one of claims 1 to 4, wherein the control circuit uses the valve device when performing a determination operation that a failure has occurred in a check valve blocking function of the check valve. A refrigerator for performing control for forcibly repeating a mode switching operation. 6. The refrigerator according to claim 5, further comprising storage means for storing the number of executions of the mode switching operation by the valve device by the control circuit. 7. The refrigerator according to claim 1, wherein the control circuit performs an operation to determine that a failure has occurred in a check valve blocking function of the check valve. A refrigerator for performing control for maintaining a state in which the number of revolutions of a cool air circulation fan is reduced. 8. The refrigerator according to claim 7, wherein the control circuit controls the rotation of the cooling air circulation fan for the refrigeration compartment to be kept at a reduced level by controlling the defrosting operation of the evaporator for the refrigeration compartment. Refrigerator characterized by releasing when finished. 9. The refrigerator according to claim 7, wherein at least the defrosting operation of the refrigeration compartment evaporator is performed at a preset cycle, and the defrosting operation cycle is set when the load on the evaporator is small. The control circuit is configured not to extend the defrosting operation cycle when executing control for maintaining the rotation speed of the refrigerated compartment cooling air circulation fan at a reduced speed. And refrigerator. 10. The refrigerator according to any one of claims 7 to 9, wherein the control circuit stores the number of times the control for maintaining the rotation speed of the cooling air circulation fan for the refrigerating compartment at a reduced state is executed. A refrigerator comprising storage means.