JPH11311466A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator for suppressing the temperature increase of a compressor by suppressing a load being applied to the compressor on pull-down operation. SOLUTION: A control device 30 for controlling the energization of a blower that circulates cold air being cooled by a cooler based on a temperature that is set by a temperature-setting means for setting the temperature of a freezing room and the temperature of the freezing room being detected by a freezing room temperature sensor 32 for detecting the temperature of the freezing room is provided with a control means 39 for reducing the conduction rate to a blower motor 40 when a temperature that is detected by a compressor temperature sensor 34 for detecting the temperature of the compressor is equal to or more than a set temperature T, a temperature that is detected by the freezing room temperature sensor 32 is equal to or more than a specific temperature Tf, and a temperature that is detected by a fresh air temperature sensor 33 is equal to or more than a specific temperature Ta.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator in which the temperature rise of a compressor during a pull-down operation is suppressed by controlling the duty ratio of a blower whose operation is controlled based on the temperature of a freezing compartment.

[0002]

2. Description of the Related Art Japanese Patent Laid-Open Publication No.
No. 8 discloses a refrigerator in which a machine room equipped with a compressor, a condenser, a blower for the condenser, and the like is arranged above the refrigerator. An evaporator and a blower for the evaporator are arranged in the refrigerator, and cool air is supplied to both the freezing room and the refrigerating room so that the temperature in the freezing room and the temperature in the refrigerating room become the respective set temperatures. Controlling the blower.

[0003] Here, the cooling capacity of a refrigerator largely depends on the capacity of a compressor and a blower. In particular, in a compressor, an overcurrent prevention relay (OLR) does not operate at the time of a pull-down operation with the largest load on the compressor. Those with great capabilities are generally preferred. However, if a compressor having a very large cooling capacity is selected, not only the cost becomes high but also the capacity becomes excessive during the cooling operation after the pull-down operation which does not require much capacity.
That is, even if the pull-down operation is good, the cooling efficiency is reduced during the cooling operation, and a compressor having a large capacity becomes uneconomical because only the required power is large. The above-mentioned pull-down operation refers to a time when the storage room is cooled from a state where the storage room is hardly cooled, for example, when turning on the power after installing the refrigerator or when using a refrigerator that has not been used for a while. is there.

Generally, a high-temperature and high-pressure gas refrigerant compressed by a compressor is liquefied in a path leading to a cooler (evaporator),
While the liquefied refrigerant exchanges heat with air circulating in the storage chamber while passing through the evaporator, it is gasified again and returned to the compressor, but in a state where the storage chamber is not cooled, the circulation The liquefied refrigerant is likely to be gasified by the evaporator due to the high temperature of the generated air, so that a large amount of liquid refrigerant is gasified and the pressure of the gas returned to the compressor increases.
For this reason, the kinetic energy required for a compressor that must compress a high-pressure gas refrigerant at a predetermined ratio (generally expressed as torque, and the magnitude of the required torque is called a load applied to the compressor) Is bigger. If the load on the compressor is large, the amount of electric power required to operate the compressor (current if the voltage is constant) increases, and if this current exceeds a predetermined value, the overcurrent prevention relay is activated and the compressor is activated. Stop. On the other hand, after the pull-down operation, since the air circulating in the storage chamber is cooled to some extent due to heat exchange at the time of the pull-down operation, the liquid refrigerant passing through the evaporator is hardly gasified, and a smaller amount of the liquid refrigerant is gasified as compared with the pull-down operation. Therefore, the pressure of the gas refrigerant returning to the compressor is reduced as compared with the pressure in the pull-down operation. For this reason, the load applied to the compressor becomes small, so that a large capacity is not required during a normal cooling operation.

[0005]

On the other hand, a blower whose operation is controlled in synchronization with the operation of the compressor is generally controlled to operate at a constant rotational speed during the above-described pull-down operation. The same is true. For this reason, the amount of air that exchanges heat with the evaporator is constant regardless of the cooling operation or the pull-down operation, and it is not possible to suppress the amount of refrigerant gasified by heat exchange in the evaporator. Cannot reduce the load. Therefore, in order to survive the pull-down operation, the capacity of the compressor must be increased, and the price of the compressor becomes high, which hinders the price control of the refrigerator. In recent years, from the viewpoint of protection of the ozone layer, a regulated refrigerant (for example, R-12) which has been conventionally used has been changed to a non-regulated refrigerant (for example, R-22). It is getting bigger.

Accordingly, an object of the present invention is to provide a refrigerator capable of using a compressor having a small capacity by suppressing the load on the compressor during the pull-down operation.

[0007]

SUMMARY OF THE INVENTION The present invention provides an outside air temperature sensor for detecting the ambient temperature of a refrigerator, a blower for circulating cool air cooled by a cooler to a freezer compartment, and a temperature setting for setting the temperature of the freezer compartment. Means, a freezer compartment temperature sensor for detecting the temperature of the freezer compartment, and a control device for controlling energization of the blower based on the freezer compartment temperature and the set temperature detected by the freezer compartment temperature sensor, the control device comprising: The present invention provides a refrigerator comprising: a compressor temperature sensor for detecting a temperature of a compressor; and control means for changing a duty ratio to the blower in accordance with the temperature detected by the compressor temperature sensor. .

[0008] The control means is provided when the temperature detected by the compressor temperature sensor is equal to or higher than the set temperature Tc and the temperature detected by the freezer compartment temperature sensor is equal to or higher than a predetermined temperature Tf higher than the set temperature of the freezer compartment. It is preferable to reduce the duty ratio to the blower.

The control means reduces the energization rate to the blower when the temperature detected by the compressor temperature sensor is equal to or higher than the set temperature Tc and the temperature detected by the outside air temperature sensor is equal to or higher than the predetermined temperature Ta. It is good to do so.

[0010]

According to the first aspect, the control unit changes the duty ratio of the blower for circulating cool air to the freezer compartment in accordance with the temperature detected by the compressor temperature sensor, so that the rotation speed of the blower is reduced. It changes according to the temperature of. For this reason, if the number of revolutions is reduced as the temperature of the compressor rises, the cooler (that is, the evaporator) during the pull-down operation at the time of turning on the power, where the load on the compressor is large and the temperature of the compressor tends to rise, ) Can be adjusted so as to reduce the circulation amount of the air that exchanges heat, and as a result, the load on the compressor during the pull-down operation is suppressed, and the rise in the temperature of the compressor can be suppressed.

According to the second aspect, when the temperature of the compressor is equal to or higher than the set temperature and the temperature of the freezing room is equal to or higher than the predetermined temperature, the duty ratio to the blower is reduced. Even so, load suppression of the compressor can be preferentially controlled, and when the temperature of the freezing room is lower than a predetermined temperature, the on / off control of the blower (for example, stop when the temperature is lower than the set temperature of the freezing room) is performed based on the temperature of the freezing room. Done. For this reason, the state before the start of operation of the compressor, such as when the power failure occurs in a state where the freezer compartment is cold and the power failure is released and the compressor is operated again (during operation after restoration from the power failure), based on the temperature of the freezer compartment. It is easy to identify the decrease in the duty ratio of the blower and, consequently, the rotation speed only during the pull-down operation when the power is turned on, and it is possible to suppress the rise in the temperature of the freezer other than during the pull-down operation.

According to the third aspect, when the temperature of the compressor is equal to or higher than the set temperature and the temperature of the outside air is equal to or higher than the predetermined temperature, the duty ratio to the blower is reduced, so that the cooling capacity for the compressor tends to be insufficient. Only when the outside air temperature is high, the duty ratio control of the blower is performed to alleviate the insufficient cooling capacity, and not at the low outside temperature where the cooling load not only for the compressor but also for the inside of the refrigerator is low, the duty ratio control of the blower is not performed, so It is possible to suppress the temperature drop speed of the freezer from becoming slow, and consequently to reduce the load on the compressor, thereby suppressing a rise in the temperature of the compressor body and a rise in the pressure of the suction port.

[0013]

FIG. 1 is a longitudinal sectional side view of a refrigerator of the present invention, FIG. 2 is a schematic block circuit diagram of a control device of the present invention, and FIG. 3 is a flowchart for explaining the operation flow of the control device. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a household refrigerator, and the refrigerator 1 has a heat-insulating box 5 having a front opening and constituting a main body thereof.
And doors 6, 8, 10, and 11 for closing the opening. The heat insulating box 5 is composed of a metal outer box 2, an inner box 3 made of a synthetic resin such as ABS, and a foam insulating material 4 filled between the inner and outer boxes. Numeral 14 denotes a horizontal partition wall for partitioning the inside of the heat insulating box 5 up and down. In this embodiment, a freezing compartment 12 is cooled above the horizontal partition wall 14 to a freezing temperature, and a lower portion is cooled to a temperature at which food does not freeze. It is a storage room 13. still,
The storage room 13 is further divided into three stages in the upper, middle, and lower portions by two horizontal partition walls 17 and 18, and a refrigerator compartment 13 B in which the upper part of the horizontal partition wall 17 is cooled to a temperature of about 3 ° C. and the lower part of the horizontal partition wall 17. The ice greenhouse 1 is cooled above the horizontal partition wall 18 to a temperature of about -1 ° C. immediately before the food is frozen below the temperature of the refrigerator compartment.
5. The lower part of the horizontal partition wall 18 is a vegetable compartment 16 cooled to a temperature suitable for storing vegetables of about 7 ° C.

The door 6 is a revolving door corresponding to the freezing room 12, and the door 8 is a revolving door corresponding to the refrigerating room 13B. The doors 10 and 11 are drawer-type doors corresponding to the ice greenhouse 15 and the vegetable chamber 16, respectively. Both doors have a top opening container 1 mainly for storing fish meat and vegetables.
9 and 20 are provided detachably. 21 and 22 are arms for supporting the speculations 19 and 20.

At the back of the freezer compartment 12, there is a cooler compartment formed by a cooler cover and a heat insulating box 5 (more specifically, the inner casing 3). This cooler compartment has a plate-fin evaporator as a cooler. 24 and a blower 25 for circulating in the refrigerator such as a sirocco fan. The cooler room communicates with the freezing room 12 at an outlet formed in the cover, and communicates with the refrigerator room 13B at the rear of the horizontal partition wall 14 by a duct (not shown). The supply of cold air to the refrigerator compartment 13B is controlled by a refrigerator damper (not shown) provided in the middle of the duct.

Next, the control device 30 of the present invention will be described with reference to the block circuit diagram of FIG. The control device 30 includes a temperature setting means (not shown) for setting the temperature of the freezer compartment, a freezer compartment temperature sensor (referred to as a freezer compartment sensor) 32 for detecting the temperature of the freezer compartment, and an atmosphere around the refrigerator (ie, outside air). An outside air temperature sensor 33 for detecting the temperature of the compressor, a compressor temperature sensor 34 disposed at a position for detecting the temperature of the compressor such as a desuperheater, and setting means and three temperature sensors 32 to
Temperature detecting means 35 for outputting a calculation signal based on the detected temperature detected at 34, various calculations are performed based on the calculation signal from the temperature detecting means 35, and signals are output to a timer measuring means 37 and an output means 38 as time measuring means. Arithmetic unit 36
The output means 38 outputs an operation stop signal for controlling the operation of the compressor 27 and a control signal for stopping the operation of the circulation blower 25 and controlling the duty ratio. The control means 39 is constituted by the temperature detecting means 35, the calculating section 36, the timer measuring means 37 and the output means 38, and the control means 39 is constituted by a microcomputer. The control signal referred to here is the motor (ie, fan motor) of the blower 4
0 and a stop signal for stopping the fan motor 40 (normal O signal).
FF signal).

When the temperature F of the freezer compartment detected by the freezer compartment sensor 32 is higher than a predetermined temperature Tf (a temperature higher than the set temperature of the freezer compartment, for example, -5.degree. C.), the calculating section 36 sets the outside air temperature. Temperature detected by sensor 33 (outside air temperature)
Is output to the timer measuring means 37 and the output means 38 when the temperature of the compressor is equal to or higher than the predetermined temperature Ta and when the temperature of the compressor detected by the compressor temperature sensor 34 is equal to or higher than the predetermined temperature Tc. I do. The timer measuring means 37 is assumed to be composed of two timers, a timer 1 and a timer 2, for the sake of the following description.

The operation flow of the control device 30 based on the above configuration will be described with reference to the flowchart of FIG.
First, when the power is turned on, a drive signal of the compressor is output in step S1, an operation signal (ON signal) of the blower fan motor 40 is output in next step S2, and a rotation speed control during pull-down operation is performed in step S3. Is set, a pull-down flag (PDFL) indicating that is set.

Next, in step S4, it is determined whether or not the pull-down flag has been set. If not, the process proceeds to step S12. If it has been set, the temperature detected by the compressor temperature sensor 34 in step S5. Is determined to be higher than the set temperature Tc. If the compressor temperature is higher than the set temperature Tc, the process proceeds to step S6. If the compressor temperature is not higher than the set temperature Tc, the process proceeds to step S12. In step S6, it is determined whether or not the temperature detected by the freezing room sensor 32 is lower than a predetermined temperature Tf (−5 ° C. in the present embodiment) that is higher than the set temperature of the freezing room. If F is lower than the predetermined temperature Tf, step S
In step S11, the pull-down flag (PDFL) is reset, and the process proceeds to step S12. If the freezing room temperature F is equal to or higher than the predetermined temperature Tf, the temperature detected by the outside air temperature sensor 33 in step S7 is equal to a predetermined temperature Ta (for example, 30 ° C.). ) Is determined. In step S7, the outside air temperature is set to a predetermined temperature Ta.
If the temperature is lower than the predetermined temperature Ta, the process proceeds to step S11.
Flag (control 1F) indicating that this is the first control mode for lowering the duty ratio of the motor 1 (specifically, the mode for lowering the rotation speed to the minimum).
L) is set, and the timer 1 is set in steps S9 and S10.
And the time of the timer 2 are respectively set in step S11.
Move to. In the case where the compressor temperature is higher than the set temperature Tc and the freezer compartment temperature is lower than the predetermined temperature Tf, when the freezer compartment becomes lower than the set temperature, a power failure occurs, and immediately after the power failure recovers, the compressor is operated. It is considered that the operation of the compressor is restarted after the defrosting operation, the compressor temperature is higher than the set temperature Tc, the freezing room temperature is higher than the predetermined temperature Tf, and the outside air temperature is higher than the predetermined temperature Ta. The low temperature may be due to the loading of food with a large load into the freezer or the door of the freezer being left open, etc. The above steps S5 to S7 are provided in order to catch the rise separately.
This makes it easier to specify that the control flag is set during the pull-down operation.

In step S12, it is determined whether or not the control 1FL has been set. If the control 1FL has not been set, the process proceeds to step S18. If the control 1FL has been set, in step S13 the duty ratio of the fan motor 40 has been set. Is set to the lowest duty ratio (for example, 5 times of 80 ms ON and 80 ms OFF).
0% duty ratio), the timer 1 is decremented in step S14, it is determined in step S15 whether the time of timer 1 has elapsed, and the fan motor is operated at this duty ratio until the timer 1 times out. (That is, step S4
If the timer 1 times out, the control 1FL is reset in step S16, and the second control mode in which the duty ratio of the fan motor 40 is slightly increased in step S17 (specifically, the mode in which the rotation speed is slightly increased from the minimum value). The flag (control 2FL) indicating that the process has shifted to is set, and the process returns to step S4.

On the other hand, in step S18, it is determined whether or not the control 2FL is set. If the control 2FL is not set, the process returns to step S4. If the control 2FL is set, the control of the fan motor 40 is performed in step S19. The duty ratio is set slightly higher than the lowest duty ratio (for example, 12
60 ms of 0 ms ON and 80 ms OFF), the timer 2 is decremented in step S20, and it is determined whether or not the time of timer 2 has elapsed in step S21. The fan motor is energized until the timer 2 times out. The operation is performed at a rate (that is, the process returns to step S4). If the timer 2 times out, the control 2FL is reset in step S22 and the process returns to step S4.

[0023]

As described above, according to the first aspect of the present invention, the energization rate to the blower for circulating cool air to the freezer compartment is changed by the control means in accordance with the temperature detected by the compressor temperature sensor. To change the rotation speed of the blower. For this reason, if the number of revolutions is reduced as the temperature of the compressor rises, the cooler (that is, the evaporator) during the pull-down operation at the time of turning on the power, where the load on the compressor is large and the temperature of the compressor tends to rise, ) Can be adjusted so as to reduce the circulation amount of the air that exchanges heat, and as a result, the load on the compressor during the pull-down operation is suppressed, and the rise in the temperature of the compressor can be suppressed.

According to the second aspect, when the temperature of the compressor is equal to or higher than the set temperature and the temperature of the freezer compartment is equal to or higher than the predetermined temperature, the power supply rate to the blower is reduced. Even so, load suppression of the compressor can be preferentially controlled, and when the temperature of the freezing room is lower than a predetermined temperature, on / off control of the blower is performed based on the temperature of the freezing room. For this reason, the state before the start of operation of the compressor, such as when the power failure occurs in a state where the freezer compartment is cold and the power failure is released and the compressor is operated again (during operation after restoration from the power failure), based on the temperature of the freezer compartment. It is easy to identify the decrease in the duty ratio of the blower and, consequently, the rotation speed only during the pull-down operation when the power is turned on, and it is possible to suppress a decrease in the rate of decrease in the temperature of the freezing compartment other than during the pull-down operation. .

According to the third aspect, when the temperature of the compressor is equal to or higher than the set temperature and the temperature of the outside air is equal to or higher than the predetermined temperature, the duty ratio to the blower is reduced, so that the cooling capacity for the compressor tends to be insufficient. Only when the outside air temperature is high, the duty ratio control of the blower is performed to alleviate the insufficient cooling capacity, and not at the low outside temperature where the cooling load not only for the compressor but also for the inside of the refrigerator is low, the duty ratio control of the blower is not performed, so It is possible to suppress the temperature drop speed of the freezer from becoming slow, and consequently to reduce the load on the compressor, thereby suppressing a rise in the temperature of the compressor body and a rise in the pressure of the suction port.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view of a refrigerator of the present invention.

FIG. 2 is a schematic block circuit diagram of a control device of the present invention.

FIG. 3 is a flowchart illustrating a flow of an operation of the control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerator 12 Freezer compartment 30 Control device 32 Freezer compartment sensor (freezer compartment temperature sensor) 33 Outside air temperature sensor (outside air temperature sensor) 34 Compressor temperature sensor 36 Operation part 39 Control means 40 Fan motor (blower)

Claims (3)

[Claims] 1. An outside air temperature sensor for detecting an ambient temperature of a refrigerator, a blower for circulating cool air cooled by a cooler to a freezing room, a temperature setting means for setting a temperature of the freezing room, and a temperature of the freezing room. In a refrigerator comprising: a freezer compartment temperature sensor for detecting, and a control device for controlling energization of the blower based on the freezer compartment temperature and the set temperature detected by the freezer compartment temperature sensor, the control device detects the temperature of the compressor. A refrigerator comprising: a compressor temperature sensor configured to perform an operation; and a control unit configured to change a duty ratio of the blower in accordance with a temperature detected by the compressor temperature sensor. 2. The control device according to claim 1, wherein the temperature of the compressor temperature sensor is equal to or higher than a set temperature and the temperature detected by the freezer compartment temperature sensor is equal to or higher than a predetermined temperature higher than the set temperature. 2. The refrigerator according to claim 1, wherein the duty ratio is reduced. 3. The control device according to claim 1, wherein the control unit reduces the duty ratio of the blower when the temperature detected by the compressor temperature sensor is equal to or higher than a set temperature and the temperature detected by the outside air temperature sensor is equal to or higher than a predetermined temperature. The refrigerator according to claim 1 or 2, wherein: