JP6847262B2 - Refrigerator, heater drive, heater drive method and program - Google Patents

Description

The present invention relates to a refrigerator, a heater drive device, a heater drive method and a program.

When frost adheres to the evaporator in the refrigerator, the heat exchange efficiency in the evaporator is lowered, and the power consumption is increased accordingly. Therefore, a refrigerator provided with a heater for removing frost adhering to the evaporator by heating the evaporator has been proposed (see, for example, Patent Document 1). The refrigerator described in Patent Document 1 includes a defrost heater that heats an evaporator that forms a part of a refrigeration cycle, a temperature sensor that detects the temperature of the evaporator or its vicinity, and a temperature within or after a predetermined time. Equipped with a control device that adjusts the defrosting end temperature in the next defrosting operation or the cycle for executing the defrosting operation based on the detection temperature of the sensor, it prevents the generation of residual frost and maintains the cooling performance of the evaporator. At the same time, it is possible to suppress the temperature rise of the storage chamber.

Japanese Unexamined Patent Publication No. 2005-331139

By the way, when an evaporator with frost is heated by a defrost heater, the temperature rises in a temperature region where the temperature of the evaporator is less than 0 ° C., and when the temperature of the evaporator reaches a region near 0 ° C., frost occurs. Begins to dissolve. As a result, the temperature of the evaporator is maintained at around 0 ° C. until all the frost adhering to the evaporator is melted. After that, when all the frost attached to the evaporator is melted, the temperature of the evaporator starts to rise again.

In the refrigerator described in Patent Document 1, the defrosting end temperature or the cycle for executing the defrosting operation in the next defrosting operation is adjusted based on the detection temperature of the temperature sensor regardless of the time profile of the temperature of the evaporator. .. Therefore, for example, when the refrigerator is used in an environment where heat is difficult to transfer from the defrost heater to the evaporator, it takes a long time for the evaporator to reach the defrosting end temperature, and when the evaporator is frosted. It is indistinguishable from the case where the time required for the evaporator to reach the defrosting end temperature is prolonged due to the adhesion of. Therefore, even though the amount of frost adhering to the evaporator is small, the defrosting end temperature in the defrosting operation may be set higher, or the cycle of the defrosting operation may be shortened. In this case, the power consumption when the refrigerator executes the defrosting operation may increase, and the temperature inside the refrigerator may also rise.

The present invention has been made in view of the above reasons, and provides a refrigerator, a heater drive device, a heater drive method, and a program capable of suppressing an increase in the temperature inside the refrigerator while reducing power consumption for defrosting. The purpose.

In order to achieve the above object, the refrigerator according to the present invention
With a cooler
With at least one heater unit that heats the cooler,
A current supply unit that supplies current to at least one heater unit, and
At least one first temperature measuring device for measuring the temperature of the cooler, and
After starting the current supply to the at least one heater unit, it is determined that the measured temperature measured by the at least one first temperature measuring device corresponds to the measured temperature when the frost adhering to the cooler melts. the duration of the state the absolute value is equal to or less than the reference temperature difference of the temperature difference between the measured temperature and the determined temperature from the time of reaching only low have a temperature preset reference temperature difference than the temperature, pre-set A determination unit that determines whether or not the temperature is equal to or longer than the specified reference time, and determines whether or not the stop condition for stopping the current supply from the current supply unit to the at least one heater unit is met.
When the determination unit determines that the duration is equal to or longer than the reference time, the current supply unit is controlled so that the calorific value of at least one heater unit is increased, and the determination unit sets the stop condition. When it is determined that the case is met, the heater control unit that controls the current supply unit so as to stop the current supply from the current supply unit to the at least one heater unit is provided.

According to the present invention, after the heater control unit starts supplying current to at least one heater unit by the determination unit, the measured temperature measured by at least one first temperature measuring device is the frost adhering to the cooler. reference temperature absolute value of the temperature difference is preset but the measured temperature and the determined temperature from the time of reaching the temperature had only a low preset reference temperature difference than the determination temperature corresponding to the measured temperature at the time of melting When it is determined that the duration of the state of the difference or less is equal to or longer than the reference time, the current supply unit is controlled so that the calorific value of at least one heater increases. As a result, the calorific value of the heater is not affected by the fluctuation of the heat transfer amount from the heater to the cooler depending on the ambient environment of the cooler or the size of the cooler, and is appropriate according to the amount of frost adhering to the cooler. Size is set. Therefore, it is possible to suppress an increase in the temperature inside the refrigerator while reducing the power consumption for defrosting.

Schematic front view of the refrigerator according to the embodiment of the present invention Schematic cross-sectional arrow view taken along line AA shown in FIG. The figure which shows the structure of the refrigerating cycle which concerns on embodiment The rear view which shows the arrangement of the cooler in the cooler room of the refrigerator which concerns on embodiment. Perspective view of the refrigerator cooler according to the embodiment Block diagram of the heater drive device according to the embodiment The figure which shows the contents of the current value database which concerns on embodiment The figure which shows the time profile of the temperature of the cooler in the case where the amount of frost attached to a cooler is relatively small, and the case where the amount of frost attached to a cooler is relatively large in the refrigerator which concerns on embodiment. A flowchart showing an example of a heater drive process executed by the control device according to the embodiment. The figure which shows the time profile of the temperature of the cooler when the ambient environment of the cooler is different in the refrigerator which concerns on embodiment. Block diagram of the heater drive device according to the embodiment Schematic front view of the refrigerator according to the embodiment of the present invention

Hereinafter, the refrigerator according to the embodiment of the present invention will be described with reference to the drawings. The refrigerator according to the present embodiment includes a heater for removing frost adhering to the cooler, a current supply unit for supplying a current to the heater, and a heater control unit for controlling the current supply unit. In addition, this refrigerator has a first temperature measuring device that measures the temperature of the cooler, a measurement temperature measured by the first temperature measuring device, and a determination temperature corresponding to the measured temperature when the frost adhering to the cooler melts. A determination unit for determining whether or not the duration of the state in which the absolute value of the temperature difference between the two and the above is equal to or less than the preset reference temperature difference is equal to or longer than the preset reference time is provided. Then, when the determination unit determines that the duration is equal to or longer than the reference time, the heater control unit controls the current supply unit so that the amount of heat generated by the heater increases.

As shown in FIG. 1, the refrigerator 1 according to the present embodiment includes a plurality of storage chambers for storing food. The refrigerator 1 has, as a plurality of storage chambers, a refrigerating chamber 10 for refrigerating food, an ice making chamber 11 for accommodating an ice maker, and a switching chamber 12 capable of switching between a temperature at which ice can be made and a temperature other than that. A vegetable compartment 13 for accommodating vegetables and a freezing chamber 14 for accommodating frozen foods and freezing the frozen foods are provided. In FIG. 1, when viewed from the front side of the refrigerator 1, the left-right direction is the X-axis direction, the vertical direction is the Z-axis direction, and the direction orthogonal to the X-axis direction and the Z-axis direction is the Y-axis direction. Further, in the refrigerator 1, the vegetable compartment 13 and the freezing chamber 14 may be interchanged in order to improve the heat transfer efficiency in refrigeration and freezing. In this case, it is preferable that the freezing chamber 14, the ice making chamber 11, and the switching chamber 12 are arranged adjacent to each other.

Further, as shown in FIG. 2, the refrigerator 1 includes a cooler chamber 16 and a machine room 18 connected to the cooler chamber 16 via a drain pipe 17. The cooler chamber 16 is connected to each of the refrigerating chamber 10, the ice making chamber 11, the switching chamber 12, the vegetable chamber 13, and the freezing chamber 14 via a cold air passage 15. A cooler 20 and a fan 30 are housed in the cooler chamber 16. Then, the cooled air existing around the cooler 20 in the cooler chamber 16 is supplied to the refrigerating chamber 10, the ice making chamber 11, and the like through the cold air passage 15 by the fan 30. Further, the compressor 40 is housed in the machine room 18. Further, the refrigerator 1 has a defrosting switch 95 operated by the user when removing frost adhering to the cooler 20, a heater unit 80 for heating the cooler 20, and a temperature measurement for measuring the temperature of the cooler 20. A vessel 90 and the like are provided. The heater unit 80 has a lower heater 80A arranged on the lower side of the cooler 20 and a side heater 80B arranged on the side of the cooler 20. The temperature measuring device 90 corresponds to the first temperature measuring device described in the claims. Further, the refrigerator 1 includes a heater drive device 100 that drives the heater unit 80 based on the measured temperature of the cooler 20 when the defrost switch 95 is turned on.

Further, the refrigerator 1 includes a condensing unit 50, a decompression unit 60, and a suction pipe 70, as shown in FIG. 3, in addition to the cooler 20 and the compressor 40. The condensing section 50, the depressurizing section 60, the cooler 20, the suction pipe 70, and the compressor 40 are each connected via the refrigerant pipe PI to form a refrigeration cycle 200. In this refrigeration cycle 200, the refrigerant flows in the order of the condensing unit 50, the decompression unit 60, the cooler 20, the suction pipe 70, and the compressor 40. By circulating the refrigerant in the freezing cycle 200, the temperature of each of the refrigerating chamber 10, the ice making chamber 11, the switching chamber 12, the vegetable chamber 13 and the freezing chamber 14 is lowered to a temperature at which food can be stored frozen or refrigerated.

The condensing unit 50 has a condensing pipe 51 and a condenser 52. The condensing pipe 51 is fixed to the housing 1a of the refrigerator 1 shown in FIGS. 1 and 2 via a fixing member, dissipates heat to the housing of the refrigerator 1 and condenses the refrigerant. Examples of the fixing member include an adhesive tape made of aluminum, an adhesive tape containing copper foil, and the like. Returning to FIG. 3, the condenser 52 includes a fin-and-tube type condenser having a condenser refrigerant pipe and fins joined to the condenser refrigerant pipe, and a wire covering the surface of the condenser refrigerant pipe and the condenser refrigerant pipe. It is a wire-and-tube type condenser or the like having the above, and is arranged in the machine room 18. The condenser 52 dissipates heat to fins, wires, and the like to condense the refrigerant.

The pressure reducing unit 60 has an expansion valve 61 and a capillary tube 62. The decompression unit 60 puts the refrigerant into a two-phase state of a liquid and a gas by decompressing and expanding the refrigerant condensed and liquefied by the condensing unit 50 to evaporate a part of the refrigerant.

As shown in FIG. 4, the cooler 20 has a cooler refrigerant pipe 21 and a plurality of fins 22 joined to the cooler refrigerant pipe 21, and the heat of the cooler refrigerant pipe 21 is a plurality of fins 22. It is released to the outside air via. The cooler 20 cools the surrounding air by the endothermic action of the evaporation of the refrigerant by evaporating the refrigerant in the liquid state among the refrigerants in the two-phase state due to the decompression in the decompression unit 60. Then, the cooled air existing around the cooler 20 is sent to the outside of the cooler chamber 16 by the fan 30.

As shown in FIG. 4, the cooler refrigerant pipe 21 has a meandering shape in the XZ plane. The cooler refrigerant pipe 21 includes a straight portion 211 extending linearly in the X-axis direction and a bent portion 212 bent so as to connect the ends of two adjacent straight portions 211 in the Z-axis direction. , Have. Further, as shown in FIG. 5, a plurality of cooler refrigerant pipes 21 exist and are arranged side by side at intervals in the Y-axis direction. Note that FIG. 5 shows a case where three cooler refrigerant pipes 21 are present. Further, as shown in FIG. 4, the plurality of fins 22 are respectively joined to the linear portions 211 of the plurality of cooler refrigerant pipes 21. As shown in FIG. 5, the plurality of fins 22 are plate-shaped members formed of metal, and are arranged at intervals along the X-axis direction.

Returning to FIG. 3, the suction pipe 70 is arranged in the heat insulating material 71 together with the capillary tube 62 of the decompression unit 60, and is joined to the capillary tube 62. The suction pipe 70 raises the temperature of the refrigerant to a temperature close to the condensation temperature by exchanging heat with the capillary tube 62. The compressor 40 compresses the cooled refrigerant in the suction pipe 70 and then sends it to the condensing unit 50.

As shown in FIG. 5, the heater unit 80 has a lower heater 80A arranged on the lower side of the cooler 20 and a side heater 80B arranged on the side of the cooler 20. By arranging the side heater 80B on the side of the cooler 20 in this way, the efficiency of removing the frost adhering to the cooler 20 is improved. The lower heater 80A is a so-called carbon type heater having a straight tube type glass tube that transmits far infrared rays and carbon fibers that are enclosed in the glass tube and emit far infrared rays when energized. Further, a heater roof 81 is provided between the lower heater 80A and the cooler 20 to prevent frost or water falling from the cooler 20 from coming into contact with the lower heater 80A. The side heater 80B has a meandering tubular glass tube that transmits infrared rays, and carbon fibers enclosed in the glass tube. The side heater 80B is arranged in a region extending from the central portion to the upper side in a region adjacent to the fins 22 of the cooler 20.

The temperature measuring device 90 has a thermistor whose electrical resistance changes in response to a change in ambient temperature. As shown in FIG. 4, for example, the temperature measuring device 90 is arranged in the header portion 21a of the cooler refrigerant pipe 21 of the cooler 20. By disposing the temperature measuring device 90 in the header portion 21a in this way, the determination temperature corresponding to the measurement temperature when the frost adhering to the cooler 20 measured by the temperature measuring device 90 melts can be determined. It can be matched to the melting point of ice. The temperature measuring device 90 is not limited to the one having a thermistor, and other types of temperature measuring devices such as a temperature measuring device using a thermocouple and a non-contact temperature measuring device such as a radiation thermometer are used. It may be.

The heater drive device 100 drives the heater unit 80 in two types of drive modes, a normal mode and a special mode in which the amount of heat generated by the heater unit 80 is increased as compared with the normal mode. As shown in FIG. 6, the heater drive device 100 includes a CPU (Central Processing Unit) 101, a main storage unit 102 composed of a volatile memory, an auxiliary storage unit 103 composed of a non-volatile memory, an interface 104, and a heater unit. It has a current supply unit 105 that supplies current to 80, and a bus 109 that connects each unit. Examples of the non-volatile memory include magnetic disks and semiconductor memories. The auxiliary storage unit 103 stores a program for executing the heater drive process described later. The interface 104 is connected to the temperature measuring instrument 90 and the defrost switch 95. The interface 104 converts the signal input from the defrost switch 95 into information indicating the on / off state of the defrost switch 95 and notifies the CPU 101. Further, the interface 104 converts the signal input from the temperature measuring device 90 into temperature information and notifies the CPU 101.

The current supply unit 105 executes, for example, a rectifying smoothing circuit that converts alternating current supplied from the system power supply into direct current, and constant current control that receives power supplied from the rectifying smoothing circuit and supplies a constant direct current to the heater unit 80. It has a power conversion circuit. Then, the current supply unit 105 supplies the heater unit 80 with a DC current having a predetermined constant current value for each of the normal mode and the special mode. The bus 109 connects the CPU 101, the main storage unit 102, the auxiliary storage unit 103, the interface 104, and the current supply unit 105 to each other.

The auxiliary storage unit 103 stores a reference database (hereinafter, referred to as “DB”) 131 for storing information related to the determination standard, a time DB 132 for storing time information, and information indicating a current value supplied to the heater unit 80. It has a current value DB 133 and a current value DB 133. The reference DB 131 stores information indicating each of the reference temperature difference, the reference time, the upper limit control temperature, and the heater drive time. Here, the reference temperature difference is a temperature that serves as a reference for the absolute value of the temperature difference between the measurement temperature measured by the temperature measuring device 90 and the melting point of the ice adhering to the cooler 20, for example, the measurement of the temperature measuring device 90. It is set based on the error. The reference time is a time that serves as a reference for the duration of a state in which the absolute value of the temperature difference between the measured temperature measured by the temperature measuring device 90 and the melting point of ice is equal to or less than the reference temperature difference. The reference temperature difference and the reference time are determined in advance by conducting an experiment, and are preset by the user. The upper limit control temperature is the upper limit temperature of the temperature of the heater unit 80. This upper limit control temperature is set to a temperature higher than the melting point of ice by at least a temperature corresponding to a reference temperature difference. The heater drive time is the time from when the current supply unit 105 starts supplying current to the heater unit 80 until when the current supply to the heater unit 80 is stopped. By the way, in the heater drive device 100 according to the present embodiment, the upper limit control temperature which is the upper limit temperature of the heater unit 80 and the heater drive time which is the maximum time for driving the heater unit 80 are appropriately changed. Therefore, the reference DB 131 provides information indicating the initial upper limit control temperature, which is the initial value of the upper limit control temperature, and the initial heater drive time, which is the initial value of the heater drive time, and information indicating the upper limit control temperature and the heater drive time. I remember it separately. Then, each time the heater drive process described later is executed, the information indicating the upper limit control temperature and the heater drive time is initially set to the information indicating the initial upper limit control temperature and the initial heater drive time at the start of the process. ..

The time DB 132 includes time information indicating the time when the temperature difference between the measured temperature of the cooler 20 and the melting point of ice first becomes equal to or less than the reference temperature difference and then continues in this state, and the measurement of the cooler 20. The time information indicating the time when the absolute value of the temperature difference between the temperature and the melting point of ice is larger than the reference temperature difference is stored separately. The time DB 132 also stores time information indicating the time immediately after the current supply from the current supply unit 105 to the heater unit 80 is started.

As shown in FIG. 7, the current value DB 133 includes the current value of the current supplied from the current supply unit 105 to the heater unit 80 in the normal mode and the current supplied from the current supply unit 105 to the heater unit 80 in the special mode. The current value and the information indicating the current value are stored.

Returning to FIG. 6, the CPU 101 reads the program stored in the auxiliary storage unit 103 into the main storage unit 102 and executes it to obtain the temperature acquisition unit 111 for acquiring the measured temperature of the cooler 20, and the timekeeping unit for measuring the time. It functions as a heater control unit 114 that controls 112, a determination unit 113, and a current supply unit 105, and a setting unit 115 that sets an upper limit control temperature and a heater drive time. The temperature acquisition unit 111 acquires the measured temperature information indicating the temperature of the cooler 20 measured by the temperature measuring device 90 via the interface 104. The temperature acquisition unit 111 periodically acquires the measured temperature information from the temperature measuring device 90, and stores the acquired measured temperature information in the main storage unit 102.

The timekeeping unit 112 has a software timer, generates time information indicating the current time, and stores it in the time DB 132. The time measuring unit 112 is based on the time information generated when the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference, and the temperature difference between the measured temperature of the cooler 20 and the melting point of ice. The time information generated when the temperature difference is larger than the temperature difference is distinguished and stored in the time DB 132.

The determination unit 113 calculates the temperature difference between the measured temperature measured by the temperature measuring device 90 and the melting point of ice. Then, the determination unit 113 determines whether or not the duration of the state in which the calculated temperature difference is equal to or less than the reference temperature difference is equal to or longer than the reference time. Further, the determination unit 113 determines whether or not the stop condition for stopping the current supply from the current supply unit 105 to the heater unit 80 has been reached. Specifically, the determination unit 113 drives the heater to determine whether or not the measurement temperature of the cooler 20 has reached the upper limit control temperature or higher, and the elapsed time from the start of current supply to the heater unit 80 by the current supply unit 105. Determine if the time has been reached.

When the determination unit 113 determines that the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference, the heater control unit 114 determines that the duration of the state is equal to or longer than the reference time. The current supply unit 105 is controlled so that the calorific value of 80 is increased. Specifically, the heater control unit 114 supplies a current so as to change the current value of the current supplied from the current supply unit 105 to the heater unit 80 from the first current value to the second current value larger than the first current value. The unit 105 is controlled. Further, when the determination unit 113 determines that the measurement temperature of the cooler 20 is equal to or higher than the upper limit control temperature, the heater control unit 114 supplies a current so as to stop the current supply from the current supply unit 105 to the heater unit 80. The unit 105 is controlled.

The setting unit 115 sets a stop condition for stopping the current supply from the current supply unit 105 to the heater unit 80. Specifically, the setting unit 115 determines that the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference is equal to or longer than the reference time according to the determination unit 113. If determined, the upper limit control temperature is set to a temperature higher by a preset temperature. For example, the initial value of the upper limit control temperature may be set to about 1 ° C., and the increase range of the upper limit control temperature may be set to 1 ° C. in advance. Further, when the determination unit 113 determines that the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference, the setting unit 115 determines that the duration of the state is equal to or longer than the reference time. The drive time is set to a longer time by a preset time. For example, the initial value of the heater drive time may be set to about 30 minutes, and the increase width of the heater drive time may be set to 5 minutes in advance.

Next, the operation of the heater drive device 100 according to the present embodiment will be described. The curve C1 in FIG. 8 shows the time profile of the measured temperature of the cooler 20 measured by the temperature measuring device 90 when frost is attached to the cooler 20. On the other hand, the curve C2 of FIG. 8 shows the time profile of the measured temperature of the cooler 20 when the amount of frost adhering to the cooler 20 is larger than that of the curve C1. Here, the current value of the current supplied from the heater drive device 100 to the heater unit 80 is constant. As shown in FIG. 8, the continuation on the curve C2 is compared with the duration ΔTi1 in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice on the curve C1 is equal to or less than the reference temperature difference ΔTeth. Time △ Ti2 is longer. This indicates that the larger the amount of frost attached to the cooler 20, the longer the time required to completely dissolve the frost. Therefore, in the heater drive device 100 according to the present embodiment, for example, a reference time ΔThh longer than the duration ΔTi1 and shorter than the duration ΔTi2 is provided. Then, the heater drive device 100 increases the current value of the current supplied from the current supply unit 105 to the heater unit 80 when the duration ΔTi2 reaches the reference time Tith or more, and melts the frost adhering to the cooler 20. To promote. In this way, the heater drive device 100 prevents wasteful supply of current from the current supply unit 105 to the heater unit 80 when the amount of frost adhering to the cooler 20 is small.

Next, the heater drive process executed by the heater drive device 100 according to the present embodiment will be described with reference to FIG. This heater drive process is started, for example, when the user turns on the defrost switch 95.

First, the heater control unit 114 controls the current supply unit 105 so as to start supplying the current to the heater unit 80 (step S101). At this time, the setting unit 115 updates the information indicating the upper limit control temperature and the heater drive time stored in the reference DB 131 to the information indicating the initial upper limit control temperature and the initial heater drive time stored in the reference DB 131.

Next, the timekeeping unit 112 generates time information immediately after the start of the heater drive process and stores it in the time DB 132 (step S102).

Subsequently, the determination unit 113 acquires information indicating the reference temperature difference ΔTeth and the reference time ΔThth from the reference DB 131 (step S103).

Then, after a lapse of a certain period of time, the temperature acquisition unit 111 acquires the measured temperature information indicating the temperature of the cooler 20 measured by the temperature measuring device 90 via the interface 104 (step S104).

Next, the determination unit 113 calculates the absolute value of the temperature difference between the measurement temperature indicated by the measurement temperature information acquired by the temperature acquisition unit 111 and the melting point of ice (step S105), and the calculated absolute value of the temperature difference is used as a reference. It is determined whether or not the temperature difference is equal to or less than the temperature difference (step S106). Here, in the process of step S105, the determination unit 113 calculates the absolute value of the temperature difference between the highest measurement temperature and the melting point of ice, which is indicated by the measurement temperature information obtained within the above-mentioned fixed time. For example, it is assumed that the maximum value of the measurement temperature indicated by the measurement temperature information acquired by the temperature acquisition unit 111 within a certain period of time is -2 ° C, and the reference temperature difference is set to 3 ° C. In this case, since the absolute value of the temperature difference between the maximum value of the measured temperature and the melting point of ice (0 ° C.) is 2 ° C., the determination unit 113 uses the calculated absolute value of the temperature difference (2 ° C.) as the reference temperature difference. It is determined that the temperature is (3 ° C.) or less.

When the determination unit 113 determines that the absolute value of the calculated temperature difference is less than the reference temperature difference ΔTeth (step S106: No), the time measuring unit 112 generates time information indicating the time at that time to generate the time. It is stored in DB 132 (step S107). Subsequently, the process of step S114 described later is executed.

On the other hand, when the determination unit 113 determines that the absolute value of the calculated temperature difference is equal to or greater than the reference temperature difference ΔTeth (step S106: Yes), the timekeeping unit 112 generates time information indicating the time at that time. And store it in the time DB 132 (step S108).

After that, the determination unit 113 calculates the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference ΔTeth based on the time information stored in the time DB 132. (Step S109), and it is determined whether or not the calculated duration is equal to or longer than the reference time ΔTith (step S110). Here, the determination unit 113 is out of the time during which this state is continued after the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice first becomes equal to or less than the reference temperature difference ΔTeth. , The duration is calculated by calculating the difference between the oldest time and the latest time.

It is assumed that the determination unit 113 determines that the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference ΔTeth is equal to or greater than the reference time ΔThh (step). S110: Yes). In this case, the heater control unit 114 determines whether or not the drive mode has already been changed (step S111). When the heater control unit 114 determines that the drive mode has not been changed (step S111: No), the heater control unit 114 changes the drive mode from the normal mode to the special mode (step S112). At this time, the heater control unit 114 refers to the current value DB 133 and sets the current value of the current supplied to the heater unit 80 from the first current value I1 corresponding to the normal mode to the first current value I1 corresponding to the special mode. The current supply unit 105 is controlled so as to change to a second current value I2 larger than that.

After that, the setting unit 115 changes the upper limit control temperature and the heater drive time (step S113). Specifically, the setting unit 115 updates the upper limit control temperature stored in the reference DB 131 to a temperature higher than the initial upper limit control temperature by a preset temperature, and sets the heater drive time stored in the reference DB 131 to the initial heater drive. Update to a time longer than the time by a preset time. After that, the process of step S103 is executed again. On the other hand, when the heater control unit 114 determines that the drive mode has already been changed (step S111: Yes), the process of step S103 is executed as it is.

Further, in the process of step S110 described above, the determination unit 113 shows that the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference ΔTeth is the reference time ΔThh. It is assumed that it is determined to be less than (step S110: No). In this case, the determination unit 113 refers to the reference DB 131 and determines whether or not the measurement temperature indicated by the measurement temperature information acquired by the temperature acquisition unit 111 is equal to or higher than the upper limit control temperature (step S114). Here, it is assumed that the determination unit 113 determines that the measurement temperature indicated by the measurement temperature information is equal to or higher than the upper limit control temperature (step S114: Yes). In this case, the heater control unit 114 controls the current supply unit 105 so as to stop the current supply to the heater unit 80 (step S115), and the heater drive process ends. At this time, the defrost switch 95 switches from the on state to the off state.

On the other hand, when the determination unit 113 determines that the measurement temperature indicated by the measurement temperature information is less than the upper limit control temperature (step S114: No), the current supply unit 105 supplies the current to the heater unit 80 with reference to the time DB 132. The elapsed time after the start of is calculated (step S116). Subsequently, the determination unit 113 refers to the time DB 132 and determines whether or not the calculated elapsed time is equal to or longer than the heater drive time (step S117). When the determination unit 113 determines that the calculated elapsed time is less than the heater drive time (step S117: No), the process of step S104 is executed again.

On the other hand, when the determination unit 113 determines that the calculated elapsed time is equal to or longer than the heater drive time (step S117: Yes), the heater control unit 114 stops the current supply from the current supply unit 105 to the heater unit 80. The current supply unit 105 is controlled so as to be performed (step S115), and the heater drive process is completed. If the user forcibly turns off the defrost switch 95 while the heater drive device 100 is executing the heater drive process, the heater drive device 100 forcibly terminates the heater drive process. ..

By the way, even if the amount of frost adhering to the cooler 20 is the same, the time profile of the measured temperature of the cooler 20 may fluctuate due to the difference in the ambient environment of the cooler 20. Curves C1 and C3 in FIG. 10 show the time profile of the measured temperature of the cooler 20 when the same amount of frost is attached to the cooler 20. Curve C3 is a time profile of the measured temperature when the ambient environment of the cooler 20 is an environment in which heat is less likely to be transferred from the heater unit 80 to the cooler 20 than the ambient environment of the cooler 20 corresponding to the curve C1. Shown. This corresponds to, for example, the case where the heat generated by the heater unit 80 is easily transferred to other than the cooler 20, or the case where the amount of heat generated by the heater unit 80 is small. Here, it is assumed that the heater drive device determines, for example, the amount of frost adhering to the cooler 20 based on the time until the measured temperature of the cooler 20 becomes equal to or higher than a preset temperature. In this case, the heater drive device erroneously determines that the amount of frost adhering to the cooler 20 is larger in the case of the curve C3 than in the case of the curve C1, and for example, the current value of the current supplied to the heater unit 80. Will be unnecessarily increased. In this case, electric power is wasted in the heater unit 80.

On the other hand, in the heater drive device 100 according to the present embodiment, the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference ΔTeth, ΔTi1 and The current value of the current supplied to the heater unit 80 is adjusted based on ΔTi3. Specifically, the heater drive device 100 does not change the current value of the current supplied to the heater unit 80 if the durations ΔTi1 and ΔTi3 are less than the reference time ΔTith. As described above, the heater drive device 100 is a heater based on the durations ΔTi1 and ΔTi3 in which the heat transferred from the heater unit 80 to the cooler 20 is consumed to melt the frost adhering to the cooler 20. The current value of the current supplied to the unit 80 is appropriately adjusted. Therefore, wasteful power consumption in the heater unit 80 is suppressed.

As described above, according to the refrigerator 1 according to the present embodiment, the determination unit 113 continues the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference. When it is determined that the time is equal to or longer than the reference time, the heater control unit 114 controls the current supply unit 105 so that the calorific value of the heater unit 80 increases. As a result, the calorific value of the heater unit 80 adheres to the cooler 20 regardless of the fluctuation of the heat transfer amount from the heater unit 80 to the cooler 20 depending on the ambient environment of the cooler 20 or the size of the cooler 20. The size is set appropriately according to the amount of frost attached. Therefore, it is possible to suppress an increase in the temperature inside the refrigerator 1 while reducing the power consumption for defrosting, and it is possible to prevent a deterioration in the quality of the food stored in the refrigerator 1.

Further, the setting unit 115 according to the present embodiment is determined by the determination unit 113 for the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference ΔTeth. When it is determined that the time is ΔThh or more, the upper limit control temperature is set to a higher temperature by a preset temperature, and the heater drive time is set to a longer time by a preset time. As a result, the residual frost adhering to the cooler 20 is suppressed, so that there is an advantage that the power consumption of the refrigerator 1 after the heater drive process is reduced.

Further, the heater control unit 114 according to the present embodiment changes the current value of the current supplied to the heater unit 80 from the first current value to the second current value larger than the first current value, thereby causing the heater unit. The current supply unit 105 is controlled so that the calorific value of 80 is increased. As a result, the heater unit 80 can be downsized, so that the entire refrigerator 1 can be downsized.

Although each embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment. For example, there may be a configuration in which a plurality of heater units for heating the cooler 20 exist. For example, assume that the refrigerator 1 includes two heater units. In this case, as shown in FIG. 11, the heater driving device 2100 may selectively drive the two heater units 281 and 282. Each of the heater units 281 and 282 has a lower heater arranged on the lower side of the cooler 20 and a side heater arranged on the side of the cooler 20, respectively. Here, the heater control unit 2114 controls the current supply unit 2105 so as to be in the first state of supplying the current to only one heater unit 281 in the normal mode. Then, when increasing the heat generation amount of the two heater units 281 and 282 as a whole, the heater control unit 2114 changes from the above-mentioned first state to the second state of supplying current to both of the two heater units 281 and 282. The current supply unit 2105 is controlled in this way. The number of heater units 80 is not limited to two, and may be three or more.

According to this configuration, it is only necessary to select and switch the heater unit 80 to which the current supply unit 2105 supplies the current. Therefore, the current supply is performed by simplifying the configuration of the power conversion circuit included in the current supply unit 2105. The configuration of the entire part 2105 can be simplified.

In the embodiment, the heater control unit 114 controls the current supply unit 105 so as to stop the current supply from the current supply unit 105 to the heater unit 80 when the measurement temperature of the cooler 20 reaches the upper limit control temperature. explained. However, the condition for stopping the current supply from the current supply unit 105 to the heater unit 80 is not limited to the measurement temperature of the cooler 20 being equal to or higher than the upper limit control temperature. For example, as shown in FIG. 12, the refrigerator 1 has temperature measuring instruments 390, 391, 392, 393, 394 provided in the refrigerator compartment 10, the ice making chamber 11, the switching chamber 12, the vegetable compartment 13 and the freezing chamber 14, respectively. Suppose you are prepared. These temperature measuring instruments 390, 391, 392, 393, 394 correspond to the second temperature measuring instruments described in the claims. In this case, when all of the measured temperatures measured by the temperature measuring instruments 390, 391, 392, 393, and 394 exceed the preset storage chamber upper limit control temperature, the heater control unit 114 receives the heater unit from the current supply unit 105. The current supply unit 105 may be controlled so as to stop the current supply to the 80. Alternatively, when at least one of the measurement temperatures measured by the temperature measuring instruments 390, 391, 392, 393, and 394 becomes equal to or higher than the preset storage chamber upper limit control temperature, the heater control unit 114 may perform the current supply unit 105. The current supply unit 105 may be controlled so as to stop the current supply to the heater unit 80.

According to this configuration, since the temperature rise in the storage chamber is suppressed, it is possible to prevent the quality of the food stored in the storage chamber from deteriorating.

In the embodiment, when the elapsed time after the start of current supply to the heater unit 80 reaches the heater drive time or more, or the measurement temperature of the cooler 20 reaches the upper limit control temperature or more. An example of terminating the heater drive process in any of the cases has been described. However, the present invention is not limited to this, in the heater drive device 100, for example, only when the elapsed time after the start of current supply to the heater unit 80 reaches the heater drive time or more, or the measurement temperature of the cooler 20 is the upper limit control temperature. The heater drive process may be terminated only when the above is reached. Alternatively, the heater drive device 100 performs the heater drive process when, for example, the elapsed time after the start of current supply to the heater unit 80 reaches the heater drive time or more and the measurement temperature of the cooler 20 reaches the upper limit control temperature or more. It may be terminated.

In the embodiment, when the duration of the state in which the absolute value of the temperature difference between the measured temperature of the cooler 20 and the melting point of ice is equal to or less than the reference temperature difference becomes equal to or longer than the reference time, the setting unit 115 sets the upper limit control temperature to a high temperature. An example of updating the heater drive time to a longer time by a preset time has been described. However, the present invention is not limited to this, and the setting unit 115 may set the heater drive time to a longer time by a preset magnification when, for example, the above-mentioned duration exceeds the reference time. Alternatively, when the above-mentioned duration exceeds the reference time, the setting unit 115 may update only the upper limit control temperature to a higher temperature and do not change the heater drive time, or may not change the upper limit control temperature. In addition, only the heater drive time may be updated to a longer time.

In the embodiment, an example in which the temperature measuring device 90 is arranged in the header portion 21a has been described, but the position of the temperature measuring device 90 is not limited to this. For example, the temperature measuring device 90 may be arranged at a portion other than the header portion 21a in the cooler 20. In this case, the determination temperature corresponding to the measurement temperature of the cooler 20 when the frost adhering to the cooler 20 melts may be higher than the melting point of ice. In this case, the determination temperature may be set to a temperature higher than the melting point of ice (0 ° C.) by a preset temperature.

In the embodiment, an example in which the temperature measuring device 90 is a temperature measuring device having a thermista has been described. For example, the temperature measuring device 90 has a pressure detector for detecting the pressure in the cooler refrigerant pipe 21 and a pressure. It may have a temperature calculator that calculates the temperature of the refrigerant corresponding to the pressure value from the pressure value detected by the detector. In this case, the determination temperature is the temperature of the refrigerant corresponding to the pressure value detected by the pressure detector, and the information indicating the reference temperature difference stored in the reference DB 131 is the refrigerant when all the refrigerant evaporates in the cooler 20. It may be used as information indicating a temperature that serves as a reference for the absolute value of the temperature difference from the evaporation temperature of. Further, in this case, in step S106 of the heater drive process described above, the determination unit 113 determines whether or not the absolute value of the temperature difference between the determination temperature described above and the evaporation temperature described above is equal to or less than the reference temperature difference. It should be.

In the embodiment, an example in which the lower heater 80A and the side heater 80B are so-called carbon type heaters, respectively, has been described, but the types of the lower heater 80A and the side heater 80B are not limited thereto. For example, the lower heater 80A and the side heater 80B may be a so-called nichrome heater having a nichrome wire, or a heater having a black body that radiates infrared rays or far infrared rays other than carbon fibers. Further, the shapes of the lower heater 80A and the side heater 80B are not limited to the above-mentioned linear and meandering shapes, and may be other shapes according to the shape of the cooler 20. Further, the arrangement of the heater unit 80 is not limited to the arrangement described in the embodiment, and other arrangements may be adopted as long as the cooler 20 can be heated.

The shape of the heater roof 81 and the type of material thereof according to the embodiment are not limited to those described above. For example, the portion of the heater roof facing the cooler 20 may be inclined along the Y-axis direction. In this case, the air heated by the lower heater 80A moves along the portion of the heater roof facing the cooler 20. As a result, the amount of heat input to the cooler refrigerant pipe 21 of the cooler 20 can be increased. Further, the heater roof 81 may be formed of an aluminum plate material and may be arranged in contact with the lower side of the cooler 20. In this case, the heat of the heater roof 81 heated by the lower heater 80A is transferred to the cooler 20, so that the efficiency of defrosting the cooler 20 is increased. In this case, it is preferable that the heater roof 81 is fixed to the cooler 20 with an aluminum tape material from the viewpoint of improving the heat transfer efficiency.

Various functions of the heater drive device 100 according to the present invention can be realized by using a computer system without relying on a dedicated system. For example, a computer connected to a network can be provided with a program for performing the above operation on a non-temporary recording medium (flexible disc, CD-ROM (Compact Disc Read-Only Memory), DVD) that can be read by the computer system. (Digital Versatile Disc), MO (Magneto-Optical Disc), etc.) may be stored and distributed, and the program may be installed in a computer system to configure a heater drive device 100 that executes the above processing.

Also, the method of providing the program to the computer is arbitrary. For example, the program may be uploaded to the server of the communication line and distributed to the computer via the communication line. Then, the computer starts this program and executes it in the same manner as other applications under the control of the OS. As a result, the computer functions as a heater driving device 100 that executes the above-mentioned processing.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the present invention. Moreover, the above-described embodiment is for explaining the present invention, and does not limit the scope of the present invention. That is, the scope of the present invention is indicated not by the embodiment but by the claims. And various modifications made within the scope of the claims and within the equivalent meaning of the invention are considered to be within the scope of the present invention.

The present invention is suitable for refrigerators or frozen showcases that need to be defrosted.

1 Refrigerator, 1a chassis, 10 Refrigerator room, 11 Ice making room, 12 Switching room, 13 Vegetable room, 14 Freezer room, 15 Cold air passage, 16 Cooler room, 17 Drain pipe, 18 Machine room, 20 Cooler, 21 Cooler Refrigerant pipe, 21a Header part, 22 fins, 30 fans, 40 compressor, 50 condensing part, 51 condensing pipe, 52 condensing part, 60 decompression part, 61 expansion valve, 62 capillary tube, 70 suction pipe, 71 insulation material, 80 heater unit, 80A lower heater, 80B side heater, 81 heater roof, 90 temperature measuring instrument, 95 defrost switch, 100, 2100 heater drive, 101 CPU, 102 main storage, 103 auxiliary storage, 104 interface, 105 Current supply unit, 109 bus, 111 temperature acquisition unit, 112 timing unit, 113 judgment unit, 114 heater control unit, 115 setting unit, 131 reference DB, 132 time DB, 133 current value DB, 200 refrigeration cycle, 211 linear unit , 212 Folded part, PI Refrigerant pipe

Claims (9)

With a cooler
With at least one heater unit that heats the cooler,
A current supply unit that supplies current to at least one heater unit, and
At least one first temperature measuring device for measuring the temperature of the cooler, and
After starting the current supply to the at least one heater unit, it is determined that the measured temperature measured by the at least one first temperature measuring device corresponds to the measured temperature when the frost adhering to the cooler melts. the duration of the state the absolute value is equal to or less than the reference temperature difference of the temperature difference between the measured temperature and the determined temperature from the time of reaching only low have a temperature preset reference temperature difference than the temperature, pre-set A determination unit that determines whether or not the temperature is equal to or longer than the specified reference time, and determines whether or not the stop condition for stopping the current supply from the current supply unit to the at least one heater unit is met.
When the determination unit determines that the duration is equal to or longer than the reference time, the current supply unit is controlled so that the calorific value of at least one heater unit is increased, and the determination unit sets the stop condition. When it is determined that the case is met, the heater control unit that controls the current supply unit to stop the current supply from the current supply unit to the at least one heater unit is provided.
refrigerator. Further provided with a setting unit for setting the stop condition,
The stop condition is that the measurement temperature is equal to or higher than the upper limit control temperature, which is at least the temperature corresponding to the reference temperature difference above the melting point of ice.
When the determination unit determines that the duration is equal to or longer than the reference time, the setting unit sets the upper limit control temperature to a temperature higher by a preset temperature.
The refrigerator according to claim 1. Further provided with a setting unit for setting the stop condition,
The stop condition is that the elapsed time from the start of current supply to the heater unit by the current supply unit is equal to or longer than the preset heater drive time.
When the determination unit determines that the duration is equal to or longer than the reference time, the setting unit sets the heater drive time to a preset time or a time longer by a preset magnification.
The refrigerator according to claim 1. Further equipped with a second temperature measuring device for measuring the temperature of at least one storage chamber,
The stop condition is that the measurement temperature measured by the second temperature measuring device becomes equal to or higher than the preset upper limit control temperature of the storage chamber.
The refrigerator according to claim 1. The heater control unit changes the current value of the current supplied to the heater unit from the first current value to the second current value larger than the first current value so that the calorific value of the heater unit increases. To control the current supply unit,
The refrigerator according to any one of claims 1 to 4. There are a plurality of the at least one heater units, and there are a plurality of such heater units.
The heater control unit supplies a current from the first state of supplying a current to the first number of heater units among the plurality of heaters to a second number of heater units having more than the first number among the plurality of heater units. By changing to the second state of supplying the current, the current supply unit is controlled so that the amount of heat generated by the plurality of heater units as a whole increases.
The refrigerator according to any one of claims 1 to 4. A current supply unit that supplies current to at least one heater unit that heats the cooler,
At least one first temperature measuring device for measuring the temperature of the cooler, and
After starting the current supply to the at least one heater unit, it is determined that the measured temperature measured by the at least one first temperature measuring device corresponds to the measured temperature when the frost adhering to the cooler melts. the duration of the state the absolute value is equal to or less than the reference temperature difference of the temperature difference between the measured temperature and the determined temperature from the time of reaching only low have a temperature preset reference temperature difference than the temperature, pre-set A determination unit that determines whether or not the temperature is equal to or longer than the specified reference time, and determines whether or not the stop condition for stopping the current supply from the current supply unit to the at least one heater unit is met.
When the determination unit determines that the duration is equal to or longer than the reference time, the current supply unit is controlled so that the calorific value of at least one heater unit is increased, and the determination unit sets the stop condition. When it is determined that the case is met, the heater control unit that controls the current supply unit to stop the current supply from the current supply unit to the at least one heater unit is provided.
Heater drive device. After starting the current supply to at least one heater unit that heats the cooler, the measured temperature measured by at least one first temperature measuring device that measures the temperature of the cooler is the frost adhering to the cooler. absolute value to the reference temperature difference of the temperature difference of but with the measured temperature and the determined temperature from the time of reaching the temperature had only a low preset reference temperature difference than the determination temperature corresponding to the measured temperature at the time of melting A step of determining whether or not the duration of the following states is equal to or longer than a preset reference time, and
A step of determining whether or not a stop condition for stopping the current supply from the current supply unit for driving the at least one heater unit to the at least one heater unit has been met.
When it is determined that the duration is equal to or longer than the reference time, the step of controlling the current supply unit so that the calorific value of at least one heater unit increases.
When it is determined that the stop condition is met, the step of controlling the current supply unit to stop the current supply from the current supply unit to the at least one heater unit is included.
Heater drive method. Computer,
After starting the current supply to the heater unit, the measurement temperature measured by at least one first temperature measuring device is set in advance than the determination temperature corresponding to the measurement temperature when the frost adhering to the cooler melts. duration of the absolute value of the state is below the reference temperature difference the temperature difference between the measured temperature and the determined temperature from the time of reaching only low have temperature reference temperature difference, at a preset reference time or more Whether or not the condition for stopping the current supply from the current supply unit for driving at least one heater unit for heating the cooler to the at least one heater unit has been met. Judgment unit,
When the determination unit determines that the duration is equal to or longer than the reference time, the current supply unit is controlled so that the calorific value of at least one heater unit is increased, and the determination unit sets the stop condition. A heater control unit that controls the current supply unit so as to stop the current supply from the current supply unit to the at least one heater unit when it is determined that the corresponding condition has been reached.
A program to function as.

Images