How to control a refrigerator

Abstract

This refrigerator provides a cooling system that can cool the interior as quickly as possible by controlling the cooling based on the outside temperature, even if the internal temperature sensor of the Peltier-type refrigerator malfunctions. [Solution] In a refrigerator comprising a refrigerator body 2, a Peltier element 29 for cooling the inside of the refrigerator compartment 26 of the refrigerator body 2, a heat sink 30 that receives heat from the Peltier element 29 and dissipates heat, a blower 35, an internal temperature sensor 31 for measuring the temperature inside the refrigerator compartment 26, an outside temperature sensor 33 for measuring the ambient temperature around the refrigerator body 2, and a control board 32 for controlling the Peltier element 29 and the blower 35, when the internal temperature sensor 31 malfunctions, the Peltier element 29 is controlled based on the detection signal from the outside temperature sensor 33, and the blower 35 is controlled at maximum airflow to suppress a decrease in the cooling rate inside the refrigerator compartment 26.

Description

Technical Field

[0001] The present invention relates to Refrigerator control method when an internal temperature sensor of a Peltier-type refrigerator fails. Background Art

[0002] Conventionally, as control for such a case, there has been known an operation device for a refrigerator, in which cool air from a cooling device is supplied into a storage compartment (corresponding to the refrigerating compartment of the present invention) through a damper, and when a temperature sensor (corresponding to the internal temperature sensor of the present invention) is abnormal, opening and closing of the damper is controlled based on a detection signal from an outdoor air sensor (corresponding to the outdoor air temperature sensor of the present invention) and a measurement result of a measurement means that measures the number of operations of the cooling device (see, for example, Patent Document 1). Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Patent No. 2851194 Summary of the Invention Problem to be Solved by the Invention

[0004] However, with such control, in an environment where the power is frequently turned on and off repeatedly, such as in a refrigerator installed in a hotel guest room, when cooling is started from a state where the internal temperature is high, cooling is controlled according to the outside air temperature without cooling the interior at once, so it takes time from when the power is turned on until the storage compartment is sufficiently cooled, and as a result, there is a problem that it takes time for an object to be cooled in the storage compartment to cool down.

[0005] The present invention solves the above problems, and provides control for a refrigerator that can cool the interior of the refrigerating compartment quickly and shorten the time required for an object to be cooled to cool down even in an environment where power is frequently turned on and off repeatedly. methodThe purpose is to provide. [Means for solving the problem]

[0006] The refrigerator control method according to claim 1 of the present invention is a refrigerator comprising: a refrigerator body; a cooling device for cooling the refrigerator compartment of the refrigerator body; a heat exchanger that receives heat from the cooling device and dissipates heat; a blower; an internal temperature sensor for measuring the temperature inside the refrigerator compartment; an outside temperature sensor for measuring the ambient temperature around the refrigerator body; and a control unit for controlling the cooling device and the blower. Control method In this configuration, the control unit controls the cooling device and the blower based on the detection signal from the internal temperature sensor when the internal temperature sensor is functioning normally, and controls the cooling device based on the detection signal from the outside air temperature sensor and controls the blower at maximum airflow when the internal temperature sensor is malfunctioning.

[0007] Furthermore, the refrigerator according to claim 2 of the present invention. Control method Claim 1, wherein when the internal temperature sensor malfunctions, the drive voltage of the cooling device is set lower than the drive voltage of the initial cooling control when the internal temperature sensor is functioning correctly. [Effects of the Invention]

[0008] The refrigerator control method described in the present invention, when configured as described above, controls the cooling device based on the detection signal from the outside air temperature sensor and controls the blower at maximum airflow when the internal temperature sensor malfunctions. This suppresses a decrease in the cooling rate inside the refrigerator compartment and allows the items to be cooled inside the refrigerator compartment to be cooled more quickly.

[0009] Furthermore, in the event of an abnormality in the internal temperature sensor, the drive voltage of the cooling device can be lowered to a lower level than the normal drive voltage of the internal temperature sensor, thereby preventing overcooling inside the refrigerator and preventing the items to be cooled placed inside the refrigerator from freezing. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of a refrigerator illustrating an embodiment of the present invention. [Figure 2] This is a front view with the door open. [Figure 3] This is a cross-sectional view of the same object. [Figure 4] This is a block diagram showing the electrical configuration. [Figure 5] This diagram shows the relationship between the outside air temperature and the voltage supplied to the Peltier element during control in the event of a malfunction in the internal temperature sensor. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described below with reference to Figures 1 to 5. In the description of these embodiments, the lower right direction in Figure 1 is considered the front, the upper left direction the rear, the upper right direction the right, and the lower left direction the left.

[0012] Reference numeral 1 denotes the refrigerator of the present invention. This refrigerator 1 comprises a refrigerator body 2 and a door 3. The refrigerator body 2 and the door 3 are connected by a hinge 4, and the door 3 can be opened and closed relative to the refrigerator body 2 by this hinge 4.

[0013] Furthermore, recessed handles 5, 5 are provided on the upper part of the door 3. These handles 5 are used to open and close the door 3.

[0014] The refrigerator body 2 is composed of a front cover 6, a middle cover 7, a rear cover 8, and an inner container 9, and an insulating material 10 is provided in the space enclosed by the front cover 6, the middle cover 7, and the inner container 9. The front cover 6, the middle cover 7, and the rear cover 8 are made of synthetic resin, and the inner container 9 is made of a thin sheet of metal with good heat conductivity such as aluminum. The insulating material 10 is made of expanded polystyrene or the like.

[0015] Further, in the refrigerator body 2, the front end portion 12 of the inner container 9 is fitted to the inner rear end portion 11 of the front cover 6, and the heat insulating material 10 is fitted from the rear side so as to cover the front cover 6 and the inner container 9. Then, the outer rear end portion 13 of the front cover 6 and the front end portion 14 of the middle cover 7 are fitted to each other, and the front cover 6 and the middle cover 7 are fixed with screws or the like.

[0016] Then, the refrigerator body 2 is assembled by fitting the rear end portion 15 of the middle cover 7 and the front end portion 16 of the rear cover 8 to each other, and fixing the middle cover 7 and the rear cover 8 with screws or the like.

[0017] The door 3 includes an upper door cover 17, a lower door cover 18, a front door cover 19, a rear door cover 20, and a heat insulating material filled in a space surrounded by the upper door cover 17, the lower door cover 18, the front door cover 19, and the rear door cover 20. The front door cover 19 is made of a thin metal plate such as a steel plate, and the upper door cover 17, the lower door cover 18, and the rear door cover 20 are made of synthetic resin.

[0018] Further, an operation unit 21 is disposed at the center of the upper front side of the door 3, and is configured to turn on and off the power supply of the refrigerator 1. A display unit 22 is disposed beside the operation unit 21, and is turned on or off in accordance with power on / off or other operations.

[0019] When the door 3 is in a closed state, a space surrounded by the front inner wall 23 of the front cover 6, the middle inner wall 24 and the rear inner wall 25 of the inner container 9, and the rear door cover 20 of the door 3 is the refrigerating compartment 26. An object to be cooled is placed into the refrigerating compartment 26.

[0020] A packing 27 is attached to the rear door cover 20. The packing 27 is made of an elastic body. When the door 3 is in the closed state, the packing 27 is in close contact with the front surface of the front cover 6, so that air in the refrigerating compartment 26 does not leak to the outside.

[0021] An aluminum block 28, which serves as a heat transfer member, is attached to the rear of the center of the rear inner wall 25 of the inner container 9 in a manner that allows for heat transfer. This aluminum block 28 is fixed to the rear inner wall 25 by screws.

[0022] The heat-absorbing surface of the Peltier element 29, which serves as a cooling device, is connected to the aluminum block 28 in a way that allows for heat transfer. Furthermore, a heat sink 30, which is a heat exchanger for heat dissipation, is connected to the heat-dissipating surface of the Peltier element 29 in a way that allows for heat transfer. In other words, the Peltier element 29 is sandwiched between the aluminum block 28 and the heat sink 30. The heat sink 30 is positioned near the rear center of the middle cover 7.

[0023] Furthermore, a temperature sensor 31 is mounted on the rear side of the inner wall 25 of the inner container 9, slightly above the center, in a manner that allows heat to be transferred, and measures the temperature inside the refrigerator compartment 26.

[0024] A control board 32, which serves as the control unit, is positioned on the lower rear side of the middle cover 7. This control board 32 is fixed to the middle cover 7 with screws or the like. In addition, an outside air temperature sensor 33 is positioned on the lower rear side of the middle cover 7, and measures the outside air temperature from a hole 34 provided in the lower part of the rear cover 8.

[0025] A blower 35 is positioned near the rear of the heat sink 30. This blower 35 is fixed to the middle cover 7 or the rear cover 8. The blower 35 takes in air from an intake port 36 located near the center of the rear of the rear cover 8 and blows the air forward. The blown air passes through the heat sink 30 and flows to the top and bottom of the rear cover 8. It is then discharged to the outside of the rear cover 8 from exhaust ports 37, 37 located at the top and bottom of the rear of the rear cover 8.

[0026] To explain the cooling of the refrigerator compartment 26, the Peltier element 29 cools the aluminum block 28, which in turn cools the inner container 9. As the inner container 9 is cooled, the inside of the refrigerator compartment 26 is cooled. Meanwhile, the heat from the Peltier element 29 is transferred to the heat sink 30.

[0027] The heat transferred to the heat sink 30 is then discharged to the outside of the refrigerator body 2 through the exhaust ports 37, 37 by the air blown out from the blower 35.

[0028] As shown in Figure 4, the control board 32 is electrically connected to the operation unit 21, the display unit 22, the Peltier element 29, the internal temperature sensor 31, the outside temperature sensor 33, and the blower 35. The control board 32 is also electrically connected to a power cord (not shown).

[0029] Now, let's describe the cooling control in this embodiment. First, the user plugs the power cord into an outlet. Then, when the user turns on the power by operating the control unit 21, the display unit 22 lights up and the refrigerator 1 starts operating.

[0030] When the refrigerator 1 starts operating, the control board 32 receives the output signal from the internal temperature sensor 31 and determines whether the internal temperature sensor 31 is functioning normally or abnormally.

[0031] If the internal temperature sensor 31 determines that the internal temperature sensor is functioning normally, the control board 32 starts control in normal mode. On the other hand, if the internal temperature sensor 31 determines that the internal temperature sensor is malfunctioning, the control board 32 starts control in abnormal mode.

[0032] In normal mode, the control board 32 controls the Peltier element 29 and the blower 35 based on the temperature T0 inside the refrigerator compartment 26 measured by the internal temperature sensor 31.

[0033] Specifically, the initial cooling control is started first, and the Peltier element 29 is operated at its maximum voltage and the blower 35 is also operated at its maximum airflow until the temperature T0 inside the refrigerator compartment 26 reaches the target temperature T1. In this embodiment, the target temperature T1 is 3°C, and the maximum voltage of the Peltier element 29 is 12V.

[0034] Then, when the temperature T0 inside the refrigerator compartment 26 falls below the target temperature T1, the initial cooling control ends and the system switches to cooling maintenance control. When the system switches to cooling maintenance control, the voltage applied to the Peltier element 29 is reduced, and the airflow of the blower 35 is also reduced. In this embodiment, the voltage applied to the Peltier element 29 is reduced to 4V, and the airflow of the blower 35 is reduced to about 60% of the maximum airflow.

[0035] Subsequently, if the temperature T0 inside the refrigerator compartment 26 rises to a temperature higher than the target temperature T1, the voltage applied to the Peltier element 29 is increased. In this embodiment, the voltage applied to the Peltier element 29 is increased to 8V. However, the airflow of the blower 35 is not changed and remains at approximately 60% of the maximum airflow.

[0036] Furthermore, unlike the case described above, if the temperature T0 inside the refrigerator compartment 26 continues to decrease, the power supply to the Peltier element 29 and the blower 35 is stopped when the temperature T0 inside the refrigerator compartment 26 falls below the cooling stop temperature T2. In this embodiment, the cooling stop temperature T2 is 1°C.

[0037] Then, when the temperature T0 inside the refrigerator compartment 26 rises and becomes higher than the target temperature T1, the cooling maintenance control described above applies a voltage of 8V to the Peltier element 29 and operates the airflow of the blower 35 at about 60% of its maximum airflow to cool the refrigerator compartment 26 so that the temperature T0 inside the refrigerator compartment 26 becomes the target temperature T1.

[0038] By performing the control as described above, the temperature T0 inside the refrigerator compartment 26 can be maintained near the target temperature T1. In this embodiment, when the temperature T0 inside the refrigerator compartment 26 falls below the target temperature T1, the airflow of the blower 35 is reduced to about 60% of the maximum airflow. This is partly because cooling inside the refrigerator compartment 26 can be maintained even with reduced airflow, but another reason is to suppress the operating noise generated by the blower 35. In this embodiment, a refrigerator installed in a hotel room is assumed, so loud operating noise would disturb sleep. Therefore, in order to suppress the operating noise of the refrigerator 1, when the temperature T0 inside the refrigerator compartment 26 falls below the target temperature T1, the airflow of the blower 35 is reduced to about 60% of the maximum airflow.

[0039] Furthermore, in normal mode, the control board 32 receives an output signal from the internal temperature sensor 31 approximately every second. If a disconnection or short circuit occurs in the internal temperature sensor 31 while operating in normal mode, and an abnormal signal is output from the output signal, the control board 32 determines that the internal temperature sensor 31 is abnormal and starts the abnormal mode control described later.

[0040] Next, control in abnormal mode will be described. If the control board 32 determines from the output signal of the internal temperature sensor 31 that the internal temperature sensor 31 is malfunctioning, it will start control in abnormal mode.

[0041] In abnormal mode, the control board 32 controls the Peltier element 29 and the blower 35 based on the ambient temperature T3 around the refrigerator body 2 measured by the ambient temperature sensor 33. It also flashes the display unit 22 to inform the user that there is an abnormality in the temperature sensor 31.

[0042] Specifically, the voltage applied to the Peltier element 29 is determined based on the ambient temperature T3 surrounding the refrigerator body 2. The voltage applied to the Peltier element 29 remains constant as long as the ambient temperature T3 does not change. At the same time, the blower 35 operates at its maximum airflow at all times.

[0043] The relationship between the ambient temperature T3 around the refrigerator body 2 and the voltage applied to the Peltier element 29 is shown in Figure 5. For example, when the ambient temperature is 30°C, the voltage applied to the Peltier element 29 is 6.3V, when the ambient temperature is 20°C, the voltage applied to the Peltier element 29 is 4.0V, and when the ambient temperature is 10°C, the voltage applied to the Peltier element 29 is 1.7V. Furthermore, when the ambient temperature is lower than 3°C, the voltage applied to the Peltier element 29 is 0V, and the Peltier element 29 stops operating. This is because, in this embodiment, since the target temperature T1 is 3°C, it can be inferred that if the ambient temperature is lower than 3°C, the temperature inside the refrigerator compartment 26 is also lower than 3°C. Therefore, there is no need to cool the inside of the refrigerator compartment 26, and the operation of the Peltier element 29 is stopped. At this time, the blower 35 continues to operate at maximum airflow, but it is also acceptable to stop the operation of the blower 35 in conjunction with the stopping of the operation of the Peltier element 29.

[0044] As shown in Figure 5, the voltage applied to the Peltier element 29 is lower than the maximum voltage that can be applied. This is to avoid a supercooling state in which the temperature inside the refrigerator compartment 26 drops too low compared to the target temperature T1, and to prevent the object being cooled from freezing.

[0045] Therefore, in normal mode, the maximum voltage is applied to the Peltier element 29 during initial cooling control to perform cooling. However, in abnormal mode, the voltage applied to the Peltier element 29 at the start of cooling is lower than in normal mode, resulting in a lower cooling rate. To mitigate the effects of this reduced cooling rate, the blower 35 is always operated at maximum airflow.

[0046] Furthermore, as mentioned above, this embodiment assumes a refrigerator installed in a hotel room. When the abnormal mode is activated, the display unit 22 flashes to inform the user of the abnormality in the refrigerator 1. Ideally, the user (for example, a hotel employee) should immediately replace it with a working refrigerator, but depending on the timing, replacement may not be possible. In such cases, instead of closing the room due to the refrigerator malfunction or posting notices that the refrigerator is unavailable, the room can be used as a temporary measure by using the refrigerator in abnormal mode, allowing it to be used in the same condition as under normal circumstances.

[0047] Furthermore, in abnormal mode, the control board 32 receives an output signal from the ambient temperature sensor 33 approximately every 10 minutes. This is because the ambient temperature T3 around the refrigerator body 2 rarely changes rapidly, so acquiring the temperature at longer intervals than in normal mode does not significantly affect the cooling control.

[0048] As described above, the refrigerator 1 comprises a refrigerator body 2, a Peltier element 29 for cooling the inside of the refrigerator compartment 26 of the refrigerator body 2, a heat sink 30 that receives heat from the Peltier element 29 and dissipates heat, a blower 35, an internal temperature sensor 31 for measuring the temperature inside the refrigerator compartment 26, an outside temperature sensor 33 for measuring the ambient temperature around the refrigerator body 2, and a control board 32 for controlling the Peltier element 29 and the blower 35. Control method In this configuration, the control board 32 controls the Peltier element 29 and the blower 35 based on the detection signal from the internal temperature sensor 31 when the internal temperature sensor 31 is functioning normally, and controls the Peltier element 29 based on the detection signal from the outside air temperature sensor 33 and controls the blower 35 at maximum airflow when the internal temperature sensor 31 is malfunctioning, thereby suppressing a decrease in the cooling rate inside the refrigerator compartment 26 and enabling the items to be cooled placed inside the refrigerator compartment 26 to be cooled quickly.

[0049] Furthermore, in the event of an abnormality in the internal temperature sensor 31, the drive voltage of the Peltier element 29 can be lowered to a level lower than the drive voltage for the initial cooling control of the internal temperature sensor under normal conditions, thereby preventing overcooling in the refrigerator compartment 26 and preventing the items to be cooled placed in the refrigerator compartment 26 from freezing.

[0050] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the gist of the invention. For example, in this embodiment, the relationship between the voltage applied to the Peltier element 29 and the ambient temperature T3 in the case of an abnormal mode is as shown in Figure 5, but this can be appropriately adjusted depending on the capacity of the refrigerator and the performance of the cooling device.

[0051] Furthermore, in normal mode, cooling control is performed based on the temperature T0 inside the refrigerator compartment 26, but the ambient temperature T3 may also be used. In other words, it is also possible to control the Peltier element 29 and the blower 35 based on two temperatures: the temperature T0 inside the refrigerator compartment 26 and the ambient temperature T3. [Explanation of Symbols]

[0052] 1. Refrigerator 2. Refrigerator unit 26 Refrigerated compartment 29. Peltier element (cooling device) 30 Heat sinks (heat exchangers) 31 Internal temperature sensor 32 Control board (control unit) 33. Outdoor temperature sensor 35 Blower

Claims

1. A refrigerator comprising a refrigerator body, a cooling device for cooling the refrigerator compartment of the refrigerator body, a heat exchanger that receives heat from the cooling device and dissipates heat, a blower, an internal temperature sensor for measuring the temperature inside the refrigerator compartment, an outside temperature sensor for measuring the ambient temperature around the refrigerator body, and a control unit for controlling the cooling device and the blower, The control unit, When the internal temperature sensor is functioning normally, the cooling device and the blower are controlled based on the detection signal from the internal temperature sensor. A refrigerator control method characterized by controlling the cooling device based on the detection signal from the outside air temperature sensor and controlling the blower at maximum airflow when the internal temperature sensor malfunctions.

2. The refrigerator according to claim 1, characterized in that when the internal temperature sensor malfunctions, the drive voltage of the cooling device is lowered to a lower voltage than the drive voltage of the initial cooling control when the internal temperature sensor is functioning correctly.

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