JP2005147594A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve cooling capacity by devising an operation control method, in a refrigerator provided with an opening/closing valve between condensers and an evaporator. <P>SOLUTION: A refrigeration cycle comprises a compressor 1, the condensers 2a, 2b, a capillary 4, and the evaporator 6. The opening/closing valve 5 is disposed between the condensers 2a, 2b and the evaporator 6. A control part 40 performs control to close the opening/closing valve 5 while continuing operation of the compressor 1, and to stop the operation of the compressor 1 after a refrigerant pressure inside the evaporator 6 falls. The control part 40 performs control to stop operation of a blower 7 for the condenser and a blower 8 for the evaporator before closing the opening/closing valve 5. the control part 40 performs control to increase a rotation speed of the compressor 1 after closing the opening/closing valve 5 and to operate the blower 8 for the evaporator. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to a refrigerator that cools an inside of a refrigerator by a refrigeration cycle in which a refrigerant is circulated in the order of a compressor, a condenser, an evaporator, and a compressor.

    In the refrigeration cycle as described above, a capillary tube and an expansion valve are arranged as a decompression device between the condenser and the evaporator. The internal temperature is controlled by ON / OFF control of the compressor. However, when the compressor is a reciprocating system and the flow of the refrigerant is limited to one direction, it is necessary to consider the following problems.

    When the compressor in operation is stopped, a large amount of high-temperature and high-pressure refrigerant stays in the condenser at that time. This high-temperature and high-pressure refrigerant flows into the evaporator through capillaries and expansion valves. In other words, the capillaries and expansion valves are originally intended to depressurize high-pressure refrigerant, but at this point, they simply act as pressure equalizing elements that eliminate the pressure difference. If high-temperature and high-pressure refrigerant flows into the evaporator, the inside temperature rises. If the internal temperature rises, the time until the compressor restarts becomes shorter. Eventually, the proportion of time during which the compressor is operating increases and the power consumption increases.

In order to solve the above problem, an on-off valve is provided between the condenser and the evaporator, and this on-off valve is closed when the operation of the compressor is stopped so that the high-temperature and high-pressure refrigerant does not flow into the evaporator. You can do it. A technique in which a valve is interposed between the condenser and the evaporator is disclosed in Patent Document 1.
Japanese Patent Laid-Open No. 56-16068 (pages 1, 2 and 2-4)

    As described above, if an open / close valve is provided between the condenser and the evaporator, the open / close valve is opened during operation of the compressor, and the open / close valve is closed when the compressor is stopped, the condenser is stopped when the compressor is stopped. Therefore, it is possible to avoid a situation in which high-temperature and high-pressure refrigerant flows into the evaporator and impairs the cooling effect. The present invention aims to further improve the cooling capacity of the refrigerator having such a configuration by adding a device to the operation control method.

    In the present invention, the refrigerator is configured as follows.

    (1) A refrigeration cycle is constituted by a compressor, a condenser, a capillary, and an evaporator, and in a refrigerator having a control unit that controls the whole, an on-off valve is disposed between the condenser and the evaporator, The control unit performs control to close the on-off valve while continuing the operation of the compressor and to stop the operation of the compressor after the refrigerant pressure inside the evaporator is reduced.

    (2) In the refrigerator configured as described above, the evaporator is divided into an evaporator for a freezer compartment and an evaporator for a refrigerator compartment, and a refrigerant is supplied to either of these evaporators, or both are supplied with a refrigerant. A switching valve was provided to change the status.

    (3) In the refrigerator configured as described above, the control unit performs control to increase the number of revolutions of the compressor after closing the on-off valve.

    (4) In the refrigerator configured as described above, an evaporator blower that forms an air flow through the evaporator is provided, and the control unit stops the operation of the evaporator blower before closing the on-off valve. Control was to be performed.

    (5) In the refrigerator configured as described above, a condenser blower that forms an air flow through the condenser is provided, and the control unit stops the operation of the condenser blower before closing the on-off valve. Control was to be performed.

    (6) In the refrigerator configured as described above, an evaporator blower that forms an air flow through the evaporator is provided, and the control unit operates the evaporator blower after stopping the operation of the compressor. Control was to be performed.

    (7) In the refrigerator configured as described above, when the control unit operates the compressor with the on-off valve closed, the refrigerant temperature inside the evaporator changes the pour point or flock point of the refrigeration oil. Control to stop the compressor operation in a higher state.

    (8) In the refrigerator configured as described above, the compressor operation is stopped based on a measured temperature of a defrost determination sensor provided in the evaporator.

    (9) In the refrigerator configured as described above, the compressor operation is stopped based on the fact that a predetermined time has elapsed after the on-off valve is closed.

    Moreover, in this invention, the refrigerator was comprised as follows.

    (10) A refrigerator including a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, and including a control unit that performs overall control, wherein the control unit continues the operation of the compressor. The expansion valve was closed and control was performed to stop the operation of the compressor after the refrigerant pressure in the evaporator decreased.

    (11) In the refrigerator configured as described above, the control unit performs control to increase the rotation speed of the compressor after closing the expansion valve.

    (12) In the refrigerator configured as described above, an evaporator blower that forms an air flow through the evaporator is provided, and the control unit stops the operation of the evaporator blower before closing the expansion valve. Control was to be performed.

    (13) In the refrigerator configured as described above, a condenser blower that forms an air flow through the condenser is provided, and the control unit stops the operation of the condenser blower before closing the expansion valve. Control was to be performed.

    (14) In the refrigerator configured as described above, an evaporator blower that forms an air flow through the evaporator is provided, and the control unit operates the evaporator blower after stopping the operation of the compressor. Control was to be performed.

    (15) In the refrigerator configured as described above, when the control unit operates the compressor with the on-off valve closed, the refrigerant temperature inside the evaporator is changed to a pour point or a flock point of refrigerating machine oil. Control to stop the compressor operation in a higher state.

    (16) In the refrigerator configured as described above, the compressor operation is stopped based on a measured temperature of a defrost determination sensor provided in the evaporator.

    (17) In the refrigerator configured as described above, the compressor operation is stopped based on the fact that a predetermined time has elapsed after the on-off valve is closed.

    (1) Prior to stopping the operation of the compressor, the on-off valve between the condenser and the evaporator is closed, so that high-temperature and high-pressure refrigerant does not flow into the evaporator. The rise is prevented. By continuing the operation of the compressor with the on-off valve closed, the refrigerant pressure inside the evaporator further decreases. Since the compressor operation is stopped after the refrigerant pressure is further lowered in this way, when the vapor phase refrigerant and the liquid phase refrigerant (liquid refrigerant) are mixed in the evaporator, the pressure rises until the equilibrium state is reached. And the evaporator continues to take heat away from the air in the cabinet with the latent heat of the liquid refrigerant for a longer time. For this reason, the cooling capacity is improved and the power consumption is also reduced.

    (2) Both the freezer compartment evaporator and the refrigerator compartment evaporator are connected to the condenser via an on-off valve. Therefore, it is possible to shut off the high-temperature and high-pressure refrigerant that is about to flow into the evaporator when the compressor is shut down, regardless of whether it is in the freezer compartment or the refrigerator compartment, and use the latent heat of the liquid refrigerant in both the refrigerator compartment and the refrigerator compartment. It is possible to suppress an increase in the temperature in the freezer compartment and the refrigerator compartment.

    (3) The control unit increases the rotational speed of the compressor after closing the on-off valve. For this reason, the refrigerant | coolant pressure inside an evaporator can be reduced in a short time, the operation stop time of a compressor can be advanced, and it can be linked with reduction of power consumption.

    (4) By providing an evaporator blower that forms an air flow through the evaporator, heat transfer between the evaporator and the internal air is promoted. Since this evaporator blower stops its operation before closing the on-off valve, the heat transfer coefficient on the evaporator surface is reduced when the on-off valve is closed. For this reason, the amount of heat transferred from the internal air to the refrigerant is reduced, and the liquid refrigerant remains in the liquid phase for a longer time. As a result, the latent heat of the liquid refrigerant is taken out over a longer period of time, and the rise in the internal temperature is further suppressed.

    (5) By providing a condenser blower that forms an air flow through the condenser, heat transfer between the condenser and outside air is promoted. This condenser blower stops operation before closing the on-off valve, and lowers the heat transfer coefficient on the condenser surface. For this reason, the supercooling of the condenser is eliminated, the amount of liquid refrigerant inside the condenser is reduced, and the refrigerant pressure inside the condenser is increased. As a result, a relatively large amount of refrigerant is pushed into the evaporator, and when the on-off valve is closed, a large amount of refrigerant remains in the evaporator. Since the total amount of refrigerant increases, the amount of liquid refrigerant increases, and more latent heat is stored inside the evaporator. Therefore, it takes a longer time to extract the latent heat of the liquid refrigerant, and the rise in the internal temperature is further suppressed.

    (6) By operating the evaporator blower after stopping the compressor operation, the internal cooling can be continued by the latent heat of the liquid refrigerant inside the evaporator.

    (7) Since the compressor operation is stopped when the refrigerant temperature inside the evaporator is higher than the pour point or flock point of the refrigerating machine oil, there is no concern that the refrigerating machine oil is separated or the refrigerating machine oil is deteriorated. .

    (8) When the compressor operation is stopped in a state where the refrigerant temperature inside the evaporator is higher than the pour point or flock point of the refrigeration oil, the compressor operation is stopped based on the measured temperature of the defrost determination sensor provided in the evaporator. Therefore, accurate control can be performed. Moreover, it is not necessary to prepare a new sensor in addition to the defrosting determination sensor, and the cost is not increased.

    (9) When the compressor operation is stopped in a state where the refrigerant temperature in the evaporator is higher than the pour point or flock point of the refrigeration oil, the compressor operation is stopped based on the fact that a predetermined time has elapsed after closing the on-off valve. Because it is assumed, control is simple.

    (10) Since the expansion valve between the condenser and the evaporator is closed prior to stopping the operation of the compressor, the high-temperature and high-pressure refrigerant does not flow into the evaporator. The rise is prevented. By continuing the operation of the compressor with the expansion valve closed, the refrigerant pressure inside the evaporator further decreases. Since the compressor operation is stopped after the refrigerant pressure is further lowered in this way, when the gas phase refrigerant and the liquid phase refrigerant coexist in the evaporator, the time until the atmospheric pressure rises and reaches the equilibrium state is that much. As it grows longer, the evaporator continues to take heat away from the cabinet air for a longer time. For this reason, the cooling capacity is improved and the power consumption is also reduced. In addition, since one expansion valve serves as a capillary tube and an on-off valve, the number of components can be reduced, and the cost can be reduced.

    (11) The control unit increases the rotation speed of the compressor after closing the expansion valve. For this reason, the refrigerant | coolant pressure inside an evaporator can be reduced in a short time, the operation stop time of a compressor can be advanced, and it can be linked with reduction of power consumption.

    (12) By providing an evaporator blower that forms an air flow through the evaporator, heat transfer between the evaporator and the internal air is promoted. Since this evaporator blower stops its operation before closing the expansion valve, the heat transfer coefficient on the evaporator surface is reduced when the expansion valve is closed. For this reason, the amount of heat transferred from the internal air to the refrigerant is reduced, and the liquid refrigerant remains in the liquid phase for a longer time. As a result, the latent heat of the liquid refrigerant is taken out over a longer period of time, and the rise in the internal temperature is further suppressed.

    (13) By providing a condenser blower that forms an air flow through the condenser, heat transfer between the condenser and outside air is promoted. This condenser blower stops operation before closing the expansion valve, and reduces the heat transfer coefficient on the condenser surface. For this reason, the supercooling of the condenser is eliminated, the amount of liquid refrigerant inside the condenser is reduced, and the refrigerant pressure inside the condenser is increased. As a result, a relatively large amount of refrigerant is pushed into the evaporator, and when the on-off valve is closed, a large amount of refrigerant remains in the evaporator. Since the total amount of refrigerant increases, the amount of liquid refrigerant increases, and more latent heat is stored inside the evaporator. Therefore, it takes a longer time to extract the latent heat of the liquid refrigerant, and the rise in the internal temperature is further suppressed.

    (14) By operating the evaporator blower after stopping the compressor operation, the internal cooling can be continued by the latent heat of the liquid refrigerant inside the evaporator.

    (15) Since the compressor operation is stopped in a state where the refrigerant temperature in the evaporator is higher than the pour point or the flock point of the refrigerating machine oil, there is no concern that the refrigerant and the refrigerating machine oil are separated or the refrigerating machine oil is deteriorated. .

    (16) When the compressor operation is stopped in a state where the refrigerant temperature inside the evaporator is higher than the pour point or flock point of the refrigeration oil, the compressor operation is stopped based on the measured temperature of the defrost determination sensor provided in the evaporator. Therefore, accurate control can be performed. Moreover, it is not necessary to prepare a new sensor in addition to the defrosting determination sensor, and the cost is not increased.

    (17) When stopping the compressor operation in a state where the refrigerant temperature in the evaporator is higher than the pour point or the flock point of the refrigerating machine oil, the compressor operation is stopped based on the passage of a predetermined time after closing the on-off valve. Because it is assumed, control is simple.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

    FIG. 1 is a configuration diagram of a refrigeration cycle of a refrigerator. FIG. 2 is a partial vertical sectional view of the refrigerator. FIG. 3 is a control block diagram. FIG. 4 is a flowchart of control. FIG. 5 is a control chart. 6 to 8 are experimental graphs.

    The refrigeration cycle shown in FIG. 1 is configured by connecting a reciprocating compressor 1, a machine room condenser 2a, an inner condenser 2b, a dryer 3, a capillary tube 4, an on-off valve 5, and an evaporator 6 in a loop shape. ing. The refrigerant which has been compressed by the compressor 1 and has become high temperature and high pressure dissipates heat and condenses when passing through the machine room condenser 2a and the inner condenser 2b. The condensed refrigerant is dehydrated by the dryer 3 and enters the capillary tube 4. The refrigerant is decompressed when it exits the capillary tube 4 and enters the evaporator 6 through the on-off valve 5 in this state. The decompressed refrigerant takes heat from the evaporator 6, and the evaporator 6 takes heat from the air surrounding it. The refrigerant that has taken heat from the air through the evaporator 6 returns to the compressor 1 and is compressed and sent out at high temperature and high pressure. This cycle is repeated, and the evaporator 6 disposed in the refrigerator compartment takes heat from the compartment air and cools the interior. Note that a condenser blower 7 that forms a cooling air flow passing therethrough is provided for the machine room condenser 2a, and an evaporator blower 8 that forms a circulating air flow passing through this is provided for the evaporator 6. Is provided.

    The arrangement | positioning condition of the said refrigerating cycle component is shown in FIG. The refrigerator includes a heat-insulating housing 20, and the inside of the housing 20 is partitioned into a freezer compartment 21 and a refrigerator compartment 22. A machine room 23 is formed in a lower corner of the back surface of the housing 20 at a corner. The compressor 1 is installed in the machine room 23 via a mount 24. The machine room condenser 2a is disposed in a space below the freezing room 21, and the condenser blower 7 installed in the machine room 23 sucks air through this. The inner condenser 2b is disposed in the side wall of the casing 20 so as to dissipate heat through the surface of the casing 20, and does not appear in FIG.

    A duct 25 is provided in front of the wall behind the freezer compartment 21. The evaporator 6 is arranged in the duct 25. The duct 25 has a circulating air flow inlet 26 at the lower part and a circulating air outlet 27 at the upper part. Both the circulating airflow inlet 26 and the circulating airflow outlet 27 are covered with a conditioned grill. The evaporator blower 8 is disposed inside the circulating airflow outlet 27.

    The refrigerant pipe 28 exiting the compressor 1 enters the duct 25 after being routed with the machine room condenser 2 a, the inner condenser 2 b, the dryer 3, and the capillary 4, and passes through the opening / closing valve 5 to the evaporator 6. Connected to. The refrigerant pipe 28 drawn out from the evaporator 6 enters the wall on the back side of the housing 20 via the liquid reservoir 29 and returns to the compressor 1 through the wall.

    A freezer temperature sensor 30 is provided in the freezer compartment 21. A defrosting determination sensor 31 that is also a temperature sensor is provided in the vicinity of the evaporator 6. A defrost heater 32 is disposed below the evaporator 6. A cover 33 is disposed between the evaporator 6 and the defrost heater 32 to prevent defrost drain from being applied to the defrost heater 32. At the bottom of the duct 25, a drain pipe 34 that passes through the machine room 23 is provided, and an evaporating dish 35 that receives the drain is installed in the machine room 23. The drain accumulated in the evaporating dish 35 is evaporated by receiving heat generated by the compressor 1 and the machine room condenser 2a.

    The air cooled by the evaporator 6 is distributed to the refrigerator compartment 22 through a duct (not shown). That is, the evaporator 6 plays a role of cooling the refrigerator compartment 22 in addition to the cooling of the freezer compartment 21.

    A control block diagram of the refrigerator 1 is shown in FIG. A control unit 40 including a microcomputer acquires temperature data from the internal temperature sensor 30 and the defrost determination sensor 31 and controls the operations of the compressor 1, the on-off valve, the condenser blower 7, the evaporator blower 8, and the defrost heater 32. To do. An operation panel 41 including a display device and operation keys is provided on the front surface of the refrigerator, and the user performs operations such as temperature adjustment through the operation panel 41.

    Next, the contents of the refrigerator operation controlled by the control unit 40 will be described based on the flowchart of FIG.

    When the control flow starts, first, in step S101, the temperature data of the freezer compartment 21 detected by the internal temperature sensor 30 is acquired. If the temperature is equal to or lower than a predetermined temperature (for example, −20 ° C.), the process proceeds to step S109. In step 109, the on-off valve 5 is closed, and the compressor 1, the evaporator blower 8, and the condenser blower 7 are all stopped. Returning from step S109 to step S101, the acquisition of the internal temperature data is executed again.

    When the temperature of the freezer compartment 21 becomes equal to or higher than the predetermined temperature, the process proceeds from step S101 to step S102 and further to step S103, and the compressor 1 is started.

    In step S102, the on-off valve 5 that has been closed is opened. In step S103, the compressor 1 starts operation. As a result, the refrigerant begins to circulate in a closed loop of compressor 1 → machine room condenser 2a → inner condenser 2b → dryer 3 → capillary 4 → open / close valve 5 → evaporator 6 → compressor 1 and the refrigeration cycle starts. Is done. The evaporator blower 8 and the condenser blower 7 also start operation.

    When the evaporator blower 8 starts operation, the air in the freezer compartment 21 flows into the duct 25 from the circulating air flow inlet 26 and rises through the evaporator 6. At this time, the air is deprived of heat by the evaporator 6 and cooled. The cooled air is sucked into the evaporator blower 8 and blown out from the circulating airflow outlet 27 to the freezer compartment 21 to cool the inside of the freezer compartment 21. Moreover, it blows off to the refrigerator compartment 22 through the duct which is not shown in figure, and cools the refrigerator compartment 22.

    When the condenser blower 7 starts operation, the outside air is sucked into the machine room 23 through the machine room condenser 2a. The machine room condenser 2a radiates heat to this air flow.

    If the pressure of the refrigerant in the machine room condenser 2a and the inner condenser 2b is compared with the pressure of the refrigerant in the evaporator 6, the latter is lower. Therefore, if the on-off valve 5 is opened in step S102, condensation occurs. High-temperature and high-pressure refrigerant enters the evaporator 6 from the evaporator side. In order to stop the temperature rise of the evaporator 6, it is better that the time interval between step S102 and step S103 is short. However, if the pressure difference between the condenser side and the evaporator side is large, the compressor 1 is difficult to start. Therefore, considering the ease of starting the compressor 1, the time interval is set to an appropriate value (for example, 30 seconds). Set.

    After starting operation of the compressor 1, the evaporator blower 8, and the condenser blower 7, the process proceeds to step S104. In step S104, the temperature data of the freezer compartment 21 detected by the internal temperature sensor 30 is acquired. If the temperature has not dropped to the predetermined temperature, the acquisition of the internal temperature data is executed again. If the temperature falls below the predetermined temperature, the process proceeds to step S105. The predetermined temperature in this case is set lower (for example, −23 ° C.) than the predetermined temperature in step S101.

    The stop operation of the compressor 1 starts from step S105. In step S105, the evaporator blower 8 and the condenser blower 7 stop operation. The rotation speed of the compressor 1 increases.

    When the evaporator blower 8 stops operation, the heat transfer coefficient on the surface of the evaporator 6 decreases, the amount of heat transferred from the internal air to the refrigerant through the evaporator 6 decreases, and the liquid refrigerant is in the liquid phase for a longer time. Stay as it is. As a result, the latent heat of the liquid refrigerant is taken out over a longer period of time, and the rise in the internal temperature is further suppressed.

    When the condenser blower 7 stops its operation, the heat transfer coefficient on the surface of the machine room condenser 2a is lowered, and the heat radiation amount in the machine room condenser 2a is reduced. For this reason, the supercooling of the machine room condenser 2a is eliminated, the amount of liquid refrigerant inside the machine room condenser 2a is reduced, and the refrigerant pressure inside the machine room condenser 2a is increased. As a result, a relatively large amount of refrigerant is pushed into the evaporator 6, and the location where the liquid refrigerant accumulates in the refrigeration cycle concentrates on the evaporator 6. That is, since the amount of liquid refrigerant in the evaporator 6 increases, more latent heat is stored in the evaporator 6 and it takes a longer time to extract the latent heat, and the rise in the internal temperature is further suppressed. .

    Further, by increasing the rotation speed of the compressor 1 while the evaporator blower 8 is stopped, the circulation amount of the refrigerant increases although the heat exchange between the internal air and the refrigerant through the evaporator 6 is small. Thus, more liquid refrigerant is accumulated in the evaporator 6.

    The process proceeds from step S105 to step S106. In step S106, it is checked whether or not a predetermined time has elapsed since the operation of the evaporator blower 8 and the condenser blower 7 was stopped. When the predetermined time has elapsed, the process proceeds to step S107. If the “predetermined time” is too long, the compressor 1 is operated during this period, and the power consumption increases. If it is too short, the liquid refrigerant does not accumulate sufficiently in the evaporator 6. Therefore, the “predetermined time” is set to a time that is not too long (for example, 2 minutes).

    In step S107, the on-off valve 5 is closed. The compressor 1 continues operation. By operating the compressor 1 with the on-off valve 5 closed, the refrigerant pressure inside the evaporator 6 decreases and the refrigerant temperature also decreases.

    The process proceeds from step S107 to step S108. In step S108, data acquisition of the defrosting determination temperature detected by the defrosting determination sensor 31 is performed. If the defrost determination temperature has not decreased to a predetermined temperature (for example, −25 ° C.), the acquisition of the internal temperature data is executed again. If the defrost determination temperature is equal to or lower than the predetermined temperature, the process proceeds to step S110.

    In step S110, the operation of the compressor 1 is stopped and the operation of the evaporator fan 8 is restarted. The on-off valve 5 remains closed, and high-temperature and high-pressure refrigerant does not flow into the evaporator 6 from the machine room condenser 2a and the inner condenser 2b, and the evaporator 6 is kept at a low temperature. Even if the compressor 1 is in a stopped state, if the evaporator blower 8 is operated, the interior cooling can be continued by the latent heat when the liquid refrigerant inside the evaporator 6 changes to the gas phase.

    The process proceeds from step S110 to step S111. In step S111, the temperature data of the freezer compartment 21 detected by the internal temperature sensor 30 is acquired. If the temperature of the freezer compartment 21 has not risen, acquisition of temperature data is executed again. If the temperature of the freezer compartment 21 has risen, it means that the latent heat of the liquid refrigerant inside the evaporator 6 can no longer be used for cooling, and the process proceeds to step S112.

    In step S112, the operation of the evaporator fan 8 is stopped. Then, the process returns to step S101.

    The control chart of FIG. 5 shows the operation / stop (ON / OFF) of the compressor 1, the evaporator blower 8, and the condenser blower 7 as described above, and the opening / closing timing of the on-off valve 5.

    In stopping the operation of the compressor 1 in step S110, the operation is stopped in a state in which the refrigerant temperature inside the evaporator 6 is higher than the pour point and the flock point of the refrigeration oil. The reason is that if the temperature inside the evaporator 6 is too low and becomes lower than the pour point or flock point of the refrigerating machine oil, the refrigerant and the refrigerating machine oil are separated or the refrigerating machine oil is altered.

    In the configuration of FIG. 2, the defrost determination sensor 31 is disposed on the evaporator 6, but the defrost determination sensor 31 may be disposed at other locations. For example, it may be arranged near the liquid reservoir 29. Moreover, the temperature sensor 30 in a store | warehouse | chamber need not be only one, but a some sensor can be arrange | positioned in each place in a store | warehouse | chamber.

    1 and 2, the on-off valve 5 is provided immediately before the evaporator 6, but may be provided immediately after the dryer 3. When the on-off valve 5 is placed immediately after the dryer 3, the high-pressure refrigerant inside the capillary tube 4 enters the evaporator 6 after the on-off valve 5 is closed, and the heat load of the freezer compartment 21 is somewhat increased. Although there is a problem, since the on-off valve 5, the capillary tube 4, and the dryer 3 can be arranged close to each other, it is easy to weld, and a merit that productivity is improved is born.

6 to 8 show graphs of the experimental results of temperature measurement. FIG. 6 relates to a refrigerator that implements the configuration of the present invention, FIG. 7 relates to a refrigerator that implements the configuration of Patent Document 1, and FIG. 8 illustrates a refrigerator that does not have an open / close valve between the condenser and the evaporator. It is concerned. In each experiment, three temperatures of the evaporator, the freezer compartment, and the refrigerator compartment were measured. The “measuring metal” used in the test is “JIS”
This is a brass cylinder having a mass of 25 g, which is described in “C9801 Characteristics and Test Method of Household Electric Refrigerator and Electric Freezer”. In the freezer compartment, the temperature was measured at a height of 1/3 of the height of the drawer case (not shown). In the refrigerator compartment, the temperature was measured at a height of 1/3 of the room height.

    In any experiment of Drawings 6-8, when a compressor is operated, cold air flows into a freezer compartment and a refrigerator compartment, and temperature falls. When the temperature of the refrigerating room decreases to a predetermined value, the cold air distributor interrupts the flow of the cold air to the refrigerating room and flows the cold air only to the freezing room. When the temperature of the freezer compartment decreases to a predetermined value, the compressor stops.

    In the experiment of FIG. 6, the refrigerator was operated according to the flowchart of FIG. However, steps S110, S111, and S112 are omitted. Further, in step S105, the control of “increasing the compressor rotational speed” is omitted, and only the control of “evaporator fan OFF, condenser fan OFF” is performed.

    In the experiment of FIG. 7, the opening / closing valve is opened when the compressor is started, and the opening / closing valve is closed when the compressor is stopped.

    In the case of a refrigerator in which no on-off valve is provided between the condenser and the evaporator, as shown in FIG. 8, the compressor stops operating and the evaporator temperature rises rapidly. On the other hand, according to the experiment of FIG. 7, it can be seen that the rise in the temperature of the evaporator is suppressed by closing the on-off valve when the compressor is stopped. This is because the high-temperature and high-pressure refrigerant in the condenser is prevented from flowing into the evaporator through the capillary.

    In the experiment of FIG. 6, the evaporator temperature is remarkably lowered immediately before the compressor is stopped. This keeps the temperature around the evaporator long and low. That is, the period during which the temperature of the freezer compartment is kept flat after the compressor is stopped is long.

    FIG. 9 shows a second embodiment of the present invention. FIG. 9 is a flowchart of control.

    The flow of the first embodiment differs from the flow of the second embodiment only in the place of step S108. That is, in the flow of the second embodiment, step S108a is inserted instead of step S108 of the first embodiment. In step S108, data acquisition of the defrosting determination temperature detected by the defrosting determination sensor 31 is performed. If the defrosting determination temperature is equal to or lower than the predetermined temperature, the process proceeds to step S110. However, in step S108a, the on-off valve 5 is closed. When the predetermined time has elapsed, the process proceeds to step S110. The “predetermined time” in this case is “a sufficient time for the evaporator temperature to fall below the predetermined temperature” and is obtained by experiment. According to this configuration, the control program is simplified because the control proceeds only with the timer count.

    FIG. 10 shows a third embodiment of the present invention. FIG. 10 is a flowchart of control.

    The flow of the first embodiment and the flow of the third embodiment are different in steps S105 and S107. That is, in the flow of the third embodiment, steps S105a and S107a are inserted instead of steps S105 and S107 of the first embodiment. In step S105, the evaporator blower 8 and the condenser blower 7 stopped operating and at the same time increased the rotational speed of the compressor 1, but in step S105a, the rotational speed of the compressor 1 was not increased and the operation was simply continued. is there. Then, step S107a is reached, and the rotation speed of the compressor 1 is increased only after the on-off valve 5 is closed. According to this configuration, the refrigerant pressure inside the evaporator 6 can be reduced in a short time, the operation stop timing of the compressor 1 can be advanced, and power consumption can be reduced.

    FIG. 11 shows a fourth embodiment of the present invention. FIG. 11 is a configuration diagram of the refrigeration cycle of the refrigerator.

    In the first embodiment, there is only one evaporator 6, and the air cooled there is distributed to the freezer compartment 21 and the refrigerator compartment 22. In 4th Embodiment, the evaporator is divided into the evaporator 6a for freezer compartment, and the evaporator 6b for refrigerator compartment. An evaporator blower 8 is provided for each of these evaporators.

    For the freezer compartment evaporator 6a and the refrigerator compartment evaporator 6b, there is provided a switching valve for switching between which one of the refrigerant flows or both of which the refrigerant flows. In the fourth embodiment, this request is met by using an open / close valve as a three-way valve. That is, the on-off valve 5a, which is a three-way valve, can selectively allow the refrigerant flowing from the dryer 3 to flow to one of the freezer evaporator 6a and the refrigerator refrigerator 6b, or both. It is also possible to prevent both from flowing.

    In 4th Embodiment, the control flow of refrigerator operation can divert the thing of 1st-3rd embodiment as it is. The effect is the same.

    FIG. 12 shows a fifth embodiment of the present invention. FIG. 12 is a configuration diagram of the refrigeration cycle of the refrigerator.

In the fifth embodiment, an expansion valve 9 is used instead of the combination of the capillary 4 and the on-off valve 5. The expansion valve 9 has both the pressure reducing action of the capillary 4 and the opening / closing action of the opening / closing valve 5.
As a result, the number of components is reduced, and the cost can be reduced.

    In 5th Embodiment, the control flow of refrigerator operation can divert the thing of 1st-3rd embodiment as it is. The effect is the same.

Refrigeration cycle block diagram of the refrigerator according to the first embodiment of the present invention. Partial vertical sectional view of the refrigerator Control block diagram Control flow chart Control chart Experiment graph Experiment graph Experiment graph The flowchart of control of the refrigerator concerning a 2nd embodiment of the present invention. The flowchart of control of the refrigerator concerning a 3rd embodiment of the present invention. Refrigeration cycle block diagram of a refrigerator according to the fourth embodiment of the present invention Refrigeration cycle block diagram of a refrigerator according to the fifth embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2a Machine room condenser 2b Inner condenser 3 Dryer 4 Capillary tube 5 On-off valve 6 Evaporator 7 Blower for condenser 8 Blower for evaporator 9 Expansion valve 20 Housing | casing 21 Freezing room 22 Refrigerating room 30 Internal temperature sensor 31 Defrosting Judgment sensor 40 Control unit

Claims (16)

In the refrigerator comprising a refrigeration cycle with a compressor, a condenser, a capillary, and an evaporator, and a control unit that controls the entire system,
An on-off valve is disposed between the condenser and the evaporator, and the control unit closes the on-off valve while continuing the operation of the compressor, and operates the compressor after the refrigerant pressure inside the evaporator decreases. The refrigerator characterized by performing control which stops.   The refrigerator according to claim 1 or 2, wherein the control unit performs control to increase the number of rotations of the compressor after the on-off valve is closed.   The evaporator blower which forms the air flow which passes along the said evaporator is provided, The said control part performs control which stops the driving | operation of the said evaporator blower before closing the said on-off valve. Refrigerator.   3. A condenser blower that forms an air flow through the condenser is provided, and the control unit performs control to stop the operation of the condenser blower before closing the on-off valve. Refrigerator.   The evaporator blower which forms the air flow which passes along the said evaporator is provided, and the said control part performs control which operates the said blower for evaporators after stopping the operation | movement of the said compressor. Refrigerator.   When the control unit operates the compressor with the on-off valve closed, the control unit performs control to stop the compressor operation in a state where the refrigerant temperature inside the evaporator is higher than the pour point or the flock point of the refrigeration oil. It performs, The refrigerator of Claim 1 or 2 characterized by the above-mentioned.   8. The refrigerator according to claim 7, wherein the compressor is stopped based on a temperature measured by a defrost determination sensor provided in the evaporator.   The refrigerator according to claim 7, wherein the compressor operation is stopped based on a lapse of a predetermined time after the on-off valve is closed. In the refrigerator comprising a refrigeration cycle with a compressor, a condenser, an expansion valve, and an evaporator, and having a control unit that controls the whole,
The said control part closes the said expansion valve, continuing the driving | operation of the said compressor, and performs control which stops the driving | operation of a compressor, after the refrigerant | coolant pressure inside the said evaporator falls.   The refrigerator according to claim 10, wherein the control unit performs control to increase a rotation speed of the compressor after closing the expansion valve.   The evaporator blower for forming an air flow through the evaporator is provided, and the control unit performs control to stop the operation of the evaporator blower before closing the expansion valve. Refrigerator.   11. The condenser blower for forming an air flow through the condenser is provided, and the control unit performs control to stop the operation of the condenser blower before closing the expansion valve. Refrigerator.   The refrigerator according to claim 10, wherein an evaporator blower that forms an air flow through the evaporator is provided, and the control unit operates the evaporator blower after stopping the operation of the compressor.   When the control unit operates the compressor with the on-off valve closed, the control unit performs control to stop the compressor operation in a state where the refrigerant temperature inside the evaporator is higher than the pour point or the flock point of the refrigeration oil. The refrigerator according to claim 10, wherein the refrigerator is performed.   16. The refrigerator according to claim 15, wherein the operation of the compressor is stopped based on a temperature measured by a defrost determination sensor provided in the evaporator.   The refrigerator according to claim 15, wherein the compressor operation is stopped based on a predetermined time elapsed after the on-off valve is closed.

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