JP2011064412A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator which saves energy by optimally controlling the rotational frequency of a fan independently from the rotational frequency of a compressor, according to the rotational frequency of the compressor and a temperature of an evaporator. <P>SOLUTION: In this refrigerator, the cooling fan is rotated in conjunction with the rotation of the compressor by a compressor control means 61, and simultaneously the cooling fan 15 is controlled to be rotated with the rotational frequency higher than the normal rotational frequency by a prescribed value by a cooling fan control means 62, under conditions that the rotational frequency of the compressor is lower than a prescribed rotational frequency set value, and a detected temperature of the evaporator is higher than a prescribed set temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerator having a refrigeration cycle in which refrigerant discharged from a compressor passes through a condenser and an evaporator and returns to the compressor again, and cools the air cooled by the evaporator by circulating it with a fan.

  The conventional refrigerator performs PID control of the compressor rotation speed according to the difference between the internal temperature and the target temperature, and operates the fan in synchronization with the operation of the compressor to cool the air cooled by the evaporator. Is circulated in the cabinet (for example, JP 2007-71492 A-Patent Document 1).

  However, in the prior art, since the fan rotation speed is controlled to rotate in synchronization with the compressor rotation speed, there are the following problems. When the door is not opened so often, the freezer temperature is kept at an appropriate freezing temperature, and the temperature difference between the target temperature and the detected temperature of the cooling chamber is small. The number is set to low speed. As a result, the number of rotations of the freezer compartment cooling fan whose rotation is controlled in synchronization with the compressor is also set to a low speed. However, if the compressor is controlled to rotate at a low speed for a long time, the refrigerant flow rate decreases, the amount of vaporization in the evaporator also decreases, the refrigerant in the freezer compartment cooling evaporator remains in a liquid state, and the temperature rises. . If the refrigerant in the evaporator remains in a liquid state, a large amount of energy is required to vaporize the liquid state refrigerant completely, resulting in energy loss.

  In order to solve such problems, the fan speed is increased separately from the compressor speed and a large amount of air is applied to the evaporator to evaporate the refrigerant therein, lowering the evaporator temperature, It is effective to increase the amount of cool air circulation in the refrigerator to quickly lower the freezer temperature to the compressor rotation stop temperature and stop the compressor rotation. However, conventionally, such a technique is not known.

JP 2007-71492 A

  The present invention has been made in view of the above-described problems of the prior art, and controls the fan at the optimum rotational speed separately from the compressor rotational speed in accordance with the state of the compressor rotational speed and the evaporator temperature. An object of the present invention is to provide a refrigerator that can save energy.

  The present invention includes a compressor that compresses a refrigerant, a condenser that condenses the refrigerant from the compressor, an evaporator that vaporizes the refrigerant that has exited the condenser, and cold air that has been cooled by the evaporator. A refrigeration cycle having a cooling fan that circulates in the room; a freezer temperature sensor that detects a freezer temperature; an evaporator temperature sensor that detects the temperature of the evaporator; and a freezer detection that is detected by the freezer temperature sensor PID control according to the temperature difference between the temperature and the freezer compartment target temperature, and compressor control means for controlling the rotation of the compressor when the temperature difference is reduced to a predetermined range; and the compression by the compressor control means The cooling fan is rotated in conjunction with the machine rotation, and the cooling fan is operated under the condition that the compressor rotational speed is lower than a predetermined rotational speed set value and the evaporator detected temperature is higher than the predetermined set temperature. The normal Than the rotational speed and said refrigerator having a cooling fan control means for controlling to rotate at a predetermined value by the high rotational speed.

  According to the refrigerator of the present invention, the cooling fan is controlled separately from the compressor rotation speed according to the state of the compressor rotation speed and the evaporator temperature, the compressor rotation speed is low, and the evaporator temperature is If it is high, increase the rotation speed of the cooling fan and apply more air to the evaporator to vaporize the refrigerant in it faster, lower the evaporator temperature, increase the amount of cool air circulation in the cabinet, and increase the freezer temperature. By quickly reducing the compressor rotation stop temperature, it is possible to save energy by eliminating the waste of rotating the compressor at a low speed for a long time.

The block diagram which shows the structure of the refrigerator main body and refrigeration cycle of the refrigerator of the 1st-3rd embodiment of this invention. The block diagram of the control part in the refrigerator of the said embodiment. The flowchart of the operation control in the refrigerator of the said embodiment. The timing chart of the refrigerating and freezing operation in the refrigerator of the said embodiment. The block diagram of the control part in the refrigerator of the 2nd Embodiment of this invention. The flowchart of the operation control in the refrigerator of the said embodiment. The flowchart of the operation control in the refrigerator of the 3rd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the refrigerator main body 1 is constituted by a heat insulating casing, and the inside thereof is insulated by a heat insulating partition wall 3 and an upper refrigerator compartment (hereinafter referred to as “R room”) 4 and a lower freezer compartment (hereinafter referred to as “ It is divided into 5). A duct 7 is formed by a partition plate 6 in the inner part of the R chamber 4, and a vegetable chamber 9 is formed by a partition plate 8 in the lower part of the R chamber 4.

  A refrigerating chamber cooling evaporator (hereinafter referred to as “R EVA”) 10 of the refrigeration cycle 2 is disposed in the lower part of the duct 7, and a blowout port 6 a is formed in the upper part of the partition plate 6. In addition, a refrigerating room cooling fan (hereinafter referred to as “R fan”) 11 is disposed at the outlet 6a. A suction port 6b that communicates the duct 7 and the vegetable compartment 9 is formed in the lower part of the partition plate 6, and a communication port 8a that communicates the R chamber 4 and the vegetable compartment 9 is formed in the partition plate 8. ing.

  A duct 13 is formed by a partition plate 12 in the inner part of the F chamber 5, and a freezer compartment cooling evaporator (hereinafter referred to as “F EVA”) 14 of the refrigeration cycle 2 is formed in the lower portion of the duct 13. It is arranged. In addition, an air outlet 12a is formed in the upper part of the partition plate 12, and a freezer compartment cooling fan (hereinafter referred to as “F fan”) 15 is disposed in the air outlet 12a. A suction port 12 b that connects the duct 13 and the F chamber 5 is formed in the lower part of the partition plate 12.

  A machine room 16 is formed in the lower part of the refrigerator body 1, and a compressor 17 of the refrigeration cycle 2 is disposed in the inner part of the machine room 16.

  The refrigerating cycle 2 of the refrigerator according to the present embodiment includes a condenser 18, a refrigerant supply device 19 including a three-way valve, and capillary tubes 20 and 21 in addition to the R evaporator 10, the F evaporator 14 and the compressor 17. The discharge port of the compressor 17 communicates with the inlet of the refrigerant supply device 19 via the condenser 18. One outlet of the refrigerant supply device 19 is communicated with the suction port of the compressor 17 through the capillary tube 20, the R evaporator 10, the connecting pipe 22, and the F evaporator 14. The other outlet of the refrigerant supply device 19 is communicated with a middle portion of the connection pipe 22 via the capillary tube 21.

  Operation control of the refrigerator of this embodiment will be described using the block diagram of FIG. 2 and the timing chart of FIG. The compressor 17 starts operation by the compressor controller 61 that controls the operation of the compressor 17 according to conditions such as the internal temperature. The compressed refrigerant is supplied to the R EVA 10 or the F EVA 14 via the refrigerant supply device 19. When the refrigerant is supplied to the R evaporator 10 or the F evaporator 14, the evaporator temperature gradually starts to decrease.

[R room cooling]
The compressor control unit 61 determines that the F room cooling has passed the maximum duration, or the F chamber cooling has passed the minimum duration, and the R room detection temperature exceeds the R room cooling start temperature RT-on. R chamber cooling is started (timing t2, t4, t6). In order to start the R chamber cooling, the compressor control unit 61 switches the refrigerant supply device 19 so that the refrigerant flows to the R evaporator 10 side. Then, the compressor control unit 61 calculates a deviation between the set temperature of the R chamber 4 and the actual temperature detected by the R room temperature sensor 51, and determines the rotational speed of the compressor 17 according to the magnitude of this deviation. If the deviation is large, the compressor 17 is rotated at a high speed, for example, 30 Hz. If the deviation is medium, the compressor 17 is rotated at a medium speed, for example, 20 Hz, and the internal temperature is If it approaches the target temperature, it is rotated at a low speed, for example 10 Hz. Further, in a situation where the R room door is opened and the internal temperature rapidly rises, the high speed operation is resumed to cool the internal chamber, and the upper rotational speed control is performed. During the cooling of the R chamber, the compressor control unit 61 operates by switching the R fan 11 to preset high speed, medium speed, and low speed in conjunction with the on / off of the compressor 17 and the rotational speed. The chilled air that has passed through the R evaporator 10 is circulated in the R chamber 4 and the vegetable chamber 9 as shown by an arrow B.

[F room cooling]
The compressor control unit 61 determines that if the R chamber cooling has passed the maximum duration, or the R chamber cooling has passed the minimum duration, and the F chamber detection temperature exceeds the F chamber cooling start temperature FT-on. F room cooling is started (timing t1, t3, t5). In order to start the F chamber cooling, the compressor control unit 61 switches the refrigerant supply device 19 so that the refrigerant flows to the F evaporator 14 side. Then, the compressor control unit 61 calculates a deviation between the set temperature of the F room 5 and the F room temperature detected by the actual F room temperature sensor 52, and determines the rotational speed of the compressor 17 according to the magnitude of the deviation PID. If the deviation is large, the compressor 17 is rotated at a high speed, for example, 30 Hz. If the deviation is medium, the compressor 17 is rotated at a medium speed, for example, 20 Hz, and the internal temperature is If it approaches the target temperature, it is rotated at a low speed, for example, 10 Hz. Further, in a situation where the F room door is opened and the internal temperature rapidly rises, the operation is returned to the high speed operation to cool the internal chamber, and the upper rotational speed control is performed.

  The F fan control unit 62 receives the compressor rotation speed information from the compressor control unit 61 and receives the F evaporator detected temperature from the F evaporator temperature sensor 53 during the cooling of the F chamber. Control the number of revolutions independently. In a normal operation state, the F fan control unit 62 operates the F fan 15 by switching between high speed, medium speed, and low speed set in advance in conjunction with the on / off of the compressor 17 and the rotation speed. The chilled air that has passed through 14 is circulated in the F chamber 5 as shown by an arrow A.

  In the refrigerator having the above configuration, when the freezer door is not opened and closed so frequently, the temperature in the F chamber 5 hardly rises between the completion of the previous F chamber cooling and the start of the current F chamber cooling. For example, when the freezer compartment temperature does not rise significantly after the transition to the R chamber cooling as in the period of the R chamber cooling end timing t7 from the R chamber cooling start time at the timing t6 in FIG. 3, the next F chamber starting from the timing t7. During the cooling period, the room F is cooled for a minimum duration. In this case, since the difference between the F room target temperature and the F room detection temperature is small, the compressor control unit 61 rotates the compressor 17 at a low speed such as 10 Hz. As described above, when the compressor 17 continues to rotate at a low speed, the amount of refrigerant vaporized in the F chamber evaporator 14 decreases, and the temperature of the F chamber evaporator 14 rises due to less absorption of the heat of vaporization. For this reason, when the internal temperature rises next and the compressor 17 is rotated at a high speed for cooling, it takes time until the liquid refrigerant is vaporized in the F evaporator 14, and the energy consumption increases. Therefore, it is preferable from the viewpoint of energy efficiency that the F evaporator 14 is kept at a low temperature.

  In the refrigerator of the present embodiment, in consideration of this point, as shown in the flowchart of FIG. 4, in the F chamber cooling, control is performed to maintain the temperature of the F evaporator 14 at a low temperature. That is, during the control to synchronize the rotational speed of the F fan with the rotational speed of the compressor 17, the rotational speed f of the compressor 17 is monitored, and when the rotational speed f becomes lower than the base rotational speed (for example, 10 Hz or lower), The detected temperature t of the evaporator temperature sensor 53 is observed (steps S1-S4). If the F evaporator temperature is higher than the set temperature, the F fan 15 is increased by one stage (medium speed) or two stages (high speed) (steps S5 and S6).

  Thus, according to the present embodiment, when the compressor 17 rotates at a low speed and the F evaporator 14 is in a high temperature state, the F fan 15 is forcibly rotated at a high speed, so If a large amount of air hits the F evaporator 14, the liquid refrigerant inside can be vaporized, and the temperature of the F evaporator 14 can be lowered. And if the temperature of F evaporator 14 falls, the air in the store | warehouse | chamber which hits this will be cooled well, the temperature of F chamber 5 can be cooled effectively, and by lowering F chamber temperature to FT-off by extension by extension. The compressor 17 can be stopped. Thereby, according to the refrigerator of this Embodiment, the compressor 17 does not continue low-speed rotation for a long time at the time of F room cooling, and can improve energy efficiency.

[Second Embodiment]
The refrigerator of the 2nd Embodiment of this invention is demonstrated using the block diagram of the control part of FIG. 5, and the flowchart of FIG. The mechanical structure of the refrigerator of the present embodiment is common to the first embodiment shown in FIG. In the refrigerator according to the present embodiment, during the cooling operation of the F room, the F fan 15 is operated on the condition that the compressor 17 rotates at a low speed, the F evaporator temperature is high, and the F room door is opened. It is characterized in that it is controlled to forcibly rotate at high speed.

  In the block diagram of FIG. 5, a point that the F room door sensor 54 is input to the F fan control unit 62 is added to the block diagram of FIG. 2. The F fan control unit 62 performs F fan control for a certain period when a door open detection signal is input to the F fan 15.

  Control of the compressor control unit 61 and the F fan control unit 62 in the refrigerator of the present embodiment will be described with reference to the flowchart of FIG. When the maximum duration time of the R room cooling has elapsed, or when the R room cooling has passed the minimum duration time, and the detected F room temperature exceeds the F room cooling start temperature FT-on, the compressor control unit 61 R room cooling is stopped, and it shifts to F room cooling.

  In the F chamber cooling, control is performed to maintain the temperature of the F evaporator 14 at a low temperature. That is, during the control to link the rotation speed of the F fan 15 to the rotation speed of the compressor 17, the rotation speed f of the compressor 17 is monitored (steps S1 and S2). The rotational speed control is started (step S11). In the F fan rotation speed control, when the rotation speed f of the F fan 15 becomes equal to or lower than the base rotation speed, the detected temperature t of the F evaporator temperature sensor 53 is observed (steps S3 and S4). If the F evaporator temperature is higher than the set temperature, the F fan 15 is increased by one stage (medium speed) or two stages (high speed) (steps S5 and S6). When the F fan 15 is forcibly rotated at a high speed, the normal operation is resumed after a predetermined time (step S7).

  Thus, according to the present embodiment, the air in the F chamber 5 whose temperature has been increased by the F fan 15 in the state where the F chamber door is opened and the temperature of the F chamber is increased is passed through the F evaporator 14. The temperature of the evaporator 14 is higher than that in the case of the first embodiment, so that a larger amount of liquid refrigerant can be vaporized, the temperature of the F evaporator 14 can be lowered more quickly, and the energy efficiency can be further improved. I can plan.

[Third Embodiment]
The refrigerator of the 3rd Embodiment of this invention is demonstrated using the flowchart of FIG. The mechanical structure of the refrigerator of this embodiment is common to the first embodiment shown in FIG. 1, and the block diagram of the control unit is common to the second embodiment shown in FIG.

  In the refrigerator of the present embodiment, during the cooling operation of the F chamber, the compressor 17 rotates at a low speed, the F evaporator temperature is high, and the F fan 15 is opened on the condition that the F chamber door is opened. It is characterized in that it is controlled to forcibly rotate at high speed. However, in the case of the present embodiment, the F evaporator temperature is compared with the first set value T1 and the second set value T2 (T1> T2) as compared with the second embodiment, and the F fan 14 depends on the level. Is characterized by different control.

  Control of the compressor control unit 61 and the F fan control unit 62 in the refrigerator of the present embodiment will be described with reference to the flowchart of FIG. When the maximum duration time of the R room cooling has elapsed, or when the R room cooling has passed the minimum duration time, and the detected F room temperature exceeds the F room cooling start temperature FT-on, the compressor control unit 61 R room cooling is stopped, and it shifts to F room cooling.

  The F fan control unit 62 performs control to maintain the temperature of the F evaporator 14 at a low temperature in the F chamber cooling. That is, during the control to link the rotation speed of the F fan 15 to the rotation speed of the compressor 17, the rotation speed f of the compressor 17 is monitored. Look at the detected temperature t (steps S1-S4). If the F evaporator temperature t is higher than the first set temperature T1, the F fan 15 is raised by one stage (medium speed) or two stages (high speed) (steps S5A and S6).

  On the other hand, if the F evaporator temperature t is not higher than the first set temperature T1, it is determined whether or not the F chamber door is opened (step S11). It is determined whether or not the evaporator temperature t is higher than the second set temperature T2 (T1> T2) (step S5B). Then, if the F chamber door is opened and the F chamber temperature is t ≧ T2, the F fan 15 is increased by one step or two steps (step S6).

  Thereby, according to this Embodiment, the effect of 1st Embodiment and 2nd Embodiment can be show | played simultaneously, and the improvement of energy efficiency can be aimed at.

DESCRIPTION OF SYMBOLS 1 Refrigerator body 2 Refrigeration cycle 4 Refrigerating room 5 Freezing room 10 Refrigerating room cooling evaporator (R evaporator)
11 Cooling room cooling fan (R fan)
14 Refrigerating room cooling evaporator (F evaporator)
15 Freezer cooling fan (F fan)
17 Compressor 18 Condenser 19 Refrigerant supply device (3-way valve)
51 Cold room temperature sensor (RT sensor)
52 Freezer temperature sensor (FT sensor)
53 F evaporator temperature sensor (FDT sensor)
54 Freezer compartment door sensor 61 Compressor controller 62 F fan controller

Claims (2)

A compressor that compresses the refrigerant; a condenser that condenses the refrigerant from the compressor; an evaporator that vaporizes the refrigerant that exits the condenser; and the cold air that is cooled by the evaporator is circulated to the freezer compartment. A refrigeration cycle having a cooling fan;
A freezer temperature sensor for detecting the freezer temperature;
An evaporator temperature sensor for detecting the temperature of the evaporator;
Compressor control that performs PID control according to the temperature difference between the freezer compartment detected temperature detected by the freezer temperature sensor and the freezer target temperature, and stops the compressor rotation when the temperature difference is reduced to a predetermined range. Means,
The cooling fan is rotated in conjunction with the rotation of the compressor by the compressor control means, the compressor rotation speed is lower than a predetermined rotation speed setting value, and the evaporator detected temperature is lower than the predetermined setting temperature. And a cooling fan control means for controlling the cooling fan to rotate at a rotational speed that is higher by a predetermined value than the normal rotational speed under high conditions. It has a door sensor that detects opening and closing of the freezer compartment door,
In addition to the condition that the compressor rotation speed is lower than a predetermined rotation speed setting value and the evaporator detection temperature is higher than a predetermined setting temperature, the cooling fan control means is configured such that the door sensor is a freezer compartment door. 2. The refrigerator according to claim 1, wherein when the opening is detected, the cooling fan is controlled to rotate at a rotational speed higher by a predetermined value than a normal rotational speed for a predetermined time.

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