JP3053896B2 - Cooling device temperature control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for a cooling device having a cooling device for cooling the inside of a refrigerator.

[0002]

2. Description of the Related Art In various types of cold storage devices such as open showcases, a temperature detector comprising a thermistor is provided in a refrigerator, and when the temperature is set to an appropriate temperature by a temperature controller in the refrigerator, the temperature becomes the set temperature. Correspondingly, an upper limit value and a lower limit value of the control target are designated, so that the temperature detected by the temperature detector is controlled within the range of each designated value. As one method of this temperature control, an electromagnetic valve for turning on / off the flow of the refrigerant from the cooling device such as a refrigerator to the cooling device is provided, and a constant temperature refrigerant is supplied to the cooling device to control the temperature in the refrigerator as a control target. There is one in which the cooling is stopped by turning it on when the upper limit is reached, and turned off when the lower limit is reached. In such a configuration, it takes a long time from turning on the solenoid valve to a steady flow, and sufficient cooling is not performed during that time. work. Therefore, the internal temperature is inverted in a state where the internal temperature exceeds the upper limit value or the lower limit value after a certain time has elapsed from ON or OFF. Therefore, the upper limit value and the lower limit value are set in consideration of the change in temperature due to this progress.

[0003]

However, in the temperature control device, the maximum value of the internal temperature reached after the solenoid valve is turned on at the upper limit value, the deviation between the upper limit value, and the temperature reached after the solenoid valve is turned off at the lower limit value. Since the deviation between the minimum value and the lower limit value changes according to the heat load on the cooling device, there has been a problem that it is not possible to satisfactorily cope with the surrounding temperature conditions and the like. In order to cope with this change in heat load, the switch of the interior light is linked so that the on / off operation temperature is automatically set higher by a certain temperature when the heat load is reduced at the time of turning off at night. However, in this case, too, the operating temperature does not follow various heat loads,
When the outside air temperature significantly changed, the inside temperature could not be properly controlled.

[0004] It is an object of the present invention to provide a temperature control device for a cold storage device in which the temperature in a refrigerator approaches a specified set temperature in a refrigerator following the heat load of the cooling device.

[0005]

According to the present invention, in order to solve the above-mentioned problems, an upper limit control target value and a lower limit control target value of the inside temperature are appropriately set in advance based on a set inside temperature. A target value designator for designating, a temperature detector for detecting a temperature in the refrigerator, and a solenoid valve for turning on / off a refrigerant flow of a cooling device for cooling the refrigerator, the upper limit control target value and the lower limit control To the target value
Correspondingly, in the temperature control device of the cool storage device that controls the internal temperature by on / off control of the solenoid valve, the maximum value and the minimum value of the internal temperature by the temperature detector for each cycle by the on / off, respectively. maximum temperature detecting means and the minimum temperature detecting means, wherein the upper control target value and the maximum value and the deviation and the deviation limit deviation calculation means and the lower deviation calculation for calculating each of said minimum value and the lower limit control target value of the to be detected Means and temperature correction information relating to the upper limit control target value and the lower limit control target value in advance corresponding to each combination of the deviations, and outputs the temperature correction information for the combination. Temperature correction information setting means, based on the temperature correction information, the upper limit control target value after the next cycle and
Control target value correcting means for correcting the lower limit control target value .

[0006]

According to the present invention, the lower limit deviation due to the difference between the lower limit control target value of the internal temperature and the minimum value of the internal temperature is determined by the upper limit control.
Than the upper limit deviation due to the difference between the control target value and the maximum value when the large and the correction value to a positive value, by previously a negative value when the small, when towards the lower limit deviation is increased next cycle after the upper control target value and the lower limit control target value Pra
Fixed to the scan side, which is when the decrease is corrected to the minus side.

[0007]

FIG. 1 is a block diagram of a temperature control device of a cool storage device according to an embodiment of the present invention, and FIG. 2 is a temperature characteristic diagram in a refrigerator by the temperature control device of FIG.

In FIG. 1, reference numeral 1 denotes a cooling device for cooling the inside of the refrigerator, 2 a solenoid valve for turning on and off the flow of the refrigerant, 3 a temperature detector for detecting a temperature TH in the refrigerator,
Reference numeral 4 denotes a target value designator for designating the reference lower limit control target value TM based on the set internal temperature.

Reference numeral 5 denotes a control target value calculating means comprising a microcomputer, which outputs a reference lower limit control target value TM designated by the target value designator 4 at the beginning according to a program described later, and sequentially corrects it. Or, it is updated and set without correction, and the new lower limit control target value T
The subsequent on / off control is performed based on HM (J). 6 is the lower limit control target value THM
Control target value setting means as control target value correction means for correcting (J).

Reference numeral 7 denotes a minimum temperature detecting means for detecting a minimum temperature K1 which continues after the internal temperature TH of the temperature detector 3 becomes equal to or lower than THM (J) set as a lower limit control target value. Reference numeral 8 denotes a maximum temperature detecting means, which is THM (J) +0.5 in which the internal temperature TH is set as the upper limit control target value.
After that, the maximum temperature K2 is detected.

Numeral 9 denotes a lower limit deviation calculating means, which calculates the lower limit deviation tB1 between the lower limit control target value THM (J) and the minimum temperature K1 by the following equation.
Calculate by tB1 = THM (J) -K1. Reference numeral 10 denotes an upper limit deviation calculating means, which is an upper limit control target value THM (J) +0.5.
The upper limit deviation tB2 between ° C. and the maximum temperature K2 is expressed by the formula: tB2 = K
Calculate by 2- (THM (J) + 0.5 ° C).

Reference numeral 11 denotes a temperature correction information setting means for associating a temperature correction value B for correcting a reference lower limit control target value TM specified in advance with a combination of a lower limit deviation tB1 and an upper limit deviation tB2. Function f (tB1, tB2), and outputs the correction value B when the maximum temperature K2 is detected. Figure 3 is a characteristic diagram of a correction value B, the
If, in accordance with the ratio and the difference between the lower limit deviation tB1 and upper deviation tB2, as as towards the lower limit deviation tB1 than the upper limit deviation tB2 is large correction value B becomes larger on the plus side, the small , The correction value B increases toward the negative side.
It is set as follows. The correction value B, the lower control target value THM (J), the lower control target value THM (J + 1) for the next cycle of the solenoid valve 2 on and off by adding calculates a correction value B of the periodic J It is for setting.
For example, the fact that the lower limit deviation tB1 is larger means that the temperature gradient of cooling when the solenoid valve 2 is in the ON period has shifted to increase , or the temperature gradient of heating due to environmental conditions in the OFF period has decreased. It means that it has moved to. Therefore, at this time, since the heat load of the cooling device is reduced, the lower limit control target value THM (J + 1) is shifted to increase. The control target value setting means 6 determines that the next cycle J +
While calculating a lower limit control target value THM (J + 1), at the output time point of the maximum temperature K2, under subsequent to this
Is output as the limit control target value THM (J).

Next, the temperature control operation according to the above configuration will be described. 4 and 5 are flowcharts showing the control operation.

As an initial setting, first, a flag Z described later becomes 1 and a flag Y becomes 0, and the minimum temperature K1 and the maximum temperature K2 related to the detected temperature TH and the on / off cycle J
The lower limit control target value THM (J) is the reference lower limit control target value TM designated by the target value designator 4 , specifically, the standard control target value THM (J).
The lower limit control target value under the rolling load condition is set (S
1). Thereafter, the solenoid valve 2 is turned on and off using the reference lower limit control target value TM. That is , the inside temperature TH is continuously read by the temperature detector 3 (S2), and when the inside temperature TH is equal to or higher than the lower limit control target value THM (J) , (S2).
3, S4), the solenoid valve 2 is turned on (open) (S5), and the flag Z is set to 2 (S6).
Becomes smaller than the lower limit control target value THM (J).
The operations of 2, S3 and S7 are repeated. And the internal temperature T
When H becomes smaller than the lower limit control target value THM (J), (S
7), the solenoid valve 2 is turned off (closed) (S8). This time is indicated by t0 in FIG. If the inside temperature TH is smaller than the lower limit control target value THM (J) in S4, the solenoid valve 2 is turned off (S9), and the flag Z is set to 3 (S10). After that, S2, S until the internal temperature TH becomes higher than the upper limit control target value THM (J) +0.5.
The operations of S3 and S11 are repeated. When the inside temperature TH becomes larger than the upper limit control target value THM (J) +0.5 (S11), the solenoid valve 2 is turned on (S12) and the flag Z is set to 2 (S13). After that, S2, S3, S7
Repeated the operation of is leading to the behavior of the previous S 8. Note that the following description will be made on the assumption that this time is t0.

Subsequently, the inside temperature TH is read (S1).
4) If the inside temperature TH is lower than or equal to the lower limit control target value THM (J) (S15, S16), after waiting for a predetermined minute time Δt (S17), if the inside temperature TH tends to decrease. If
If the inside temperature TH is lower than the minimum temperature K1 (S1
8) The minimum temperature K1 is rewritten to the internal chamber temperature TH (S
19). At this time, the solenoid valve 2 is off (S2
0), the internal temperature TH is equal to the upper limit control target value THM (J) +0.
If it is smaller than 5 (S21), S14 to S21 are repeated. As a result, when the inside temperature TH becomes equal to or higher than the minimum temperature K1 at time t1 (S18), the minimum temperature detection means 7
, The minimum temperature K1 is taken (S22). Subsequently, S14 to S18, S22, S20, and S21 are repeated, and at time t2, the temperature TH in the refrigerator becomes the lower limit control target value T.
HM becomes greater than (J) (S16), waiting for a predetermined minute time Delta] t (S23), if the inside temperature TH upward trend, that is, the inside temperature TH is greater than the maximum temperature K2 (S24), the maximum The temperature K2 is rewritten to the internal temperature TH (S25), and S14 to S18, S22, S20, S21.
Is repeated. As a result, at time t3, the internal temperature T
When H becomes equal to or higher than the upper limit control target value THM (J) +0.5 (S21), the solenoid valve 2 is turned on (S26). Subsequently, S14 to S16, S22, and S20 are executed, and if the inside temperature TH is higher than the lower limit control target value THM (J) (S2
7) These are repeated. As a result, when the inside temperature TH becomes equal to or lower than the maximum temperature K2 at time t4 (S2
4) The maximum temperature K2 is taken in the maximum temperature detecting means 8 (S28). Here, the lower limit deviation calculating means 9 calculates the lower limit deviation tB1 by the formula: tB1 = THM (J) -K1 (S29), and the upper limit deviation calculating means 10 calculates the upper limit deviation tB2 by the formula: tB2 = K2- (THM (J) +
0.5) (S30). Then, the correction value B is calculated by the temperature correction information setting means 11 into an equation, B = f (tB
1, tB2) (S30). Further, in the control target value setting means 6, the lower limit control target value THM (J + 1) of the next cycle J + 1 is calculated by the following expression: THM (J +
1) calculated by THM (J) + B (S32),
The control target value setting unit 6, the lower control target value THM
(J + 1) is a new lower limit control target value THM
(J) is output (S33). Then, the flag Y becomes 1 (S34). If the internal chamber temperature TH is still higher than the new lower limit control target value THM (J) (S27), S1 is executed.
4, S15, S20, and S27 are repeated, and at time t5, when the value falls below the lower limit control target value THM (J) (S2
7), the solenoid valve 2 is turned off (S35). Then, the flag Y becomes 0 (S36), and the minimum temperature K1 and the maximum temperature K2
Is reset to the lower limit control target value THM (J) (S3
7, S38). The same control as the operation time t0 after the based on the lower control target value THM (J) is repeated. This lower limit control target value THM (J) is updated every ON / OFF cycle of the solenoid valve 2 and controlled similarly.

[0016]

As described above, according to the present invention, the upper limit control target value and the lower limit control for on / off control of the cooling operation are provided.
For the control target value , temperature correction information corresponding to a combination of an upper limit deviation that rises after the solenoid valve is turned off and a lower limit deviation that falls after the solenoid valve is turned on is set, and a new value is corrected by the temperature correction information. Since the upper-limit control target value and the lower-limit control target value are set, the temperature correction information is set in advance so that the new upper-limit control target value and lower-limit control target value compensate for fluctuations in the heat load. In this way, even if the heat load fluctuates, the control is performed such that the internal temperature approaches the specified set internal temperature .

[Brief description of the drawings]

FIG. 1 is a block diagram of a temperature control device of a cool storage device according to an embodiment of the present invention.

FIG. 2 is a temperature characteristic diagram in a refrigerator by the temperature control device of FIG. 1;

FIG. 3 is a characteristic diagram of a temperature correction value.

FIG. 4 is a flowchart showing a control operation of the temperature control device of FIG. 1;

FIG. 5 is a flowchart showing a control operation of the temperature control device of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cooling device, 2 ... Solenoid valve, 3 ... Temperature detector, 4 ... Target value designator, 6 ... Control target value setting means, 7 ... Minimum temperature detection means, 8 ... Maximum temperature detection means, 9 ... Lower limit deviation calculation means,
10: Upper limit deviation calculating means, 11: Temperature correction information setting means.

Claims (1)

(57) [Claims] A target value designator for appropriately designating an upper limit control target value and a lower limit control target value of the internal temperature based on the set internal temperature in advance, and a temperature detector for detecting the internal temperature. Vessel, a solenoid valve for turning on and off the flow of the refrigerant of the cooling device for cooling the inside of the refrigerator, the upper limit control target value and the lower limit control target value
Correspondingly, in a temperature control device of a cold storage device that controls the internal temperature by controlling on / off of an electromagnetic valve, a maximum value and a minimum value of the internal temperature by the temperature detector for each cycle by the on / off, respectively. and the maximum temperature detecting means and the minimum temperature detecting means detect the deviation and the lower limit of the maximum value and the upper limit control target value
An upper limit deviation calculating means and a lower limit deviation calculating means for respectively calculating a deviation between a control target value and the minimum value, and an upper limit control target value corresponding to each combination of the deviations.
Temperature correction information relating to the lower limit control target value is set in advance, the temperature correction information setting means for outputting the temperature correction information for the combination, and the upper limit control for the next cycle or later based on the temperature correction information. <br/> A control target value for correcting the control target value and the lower limit control target value
And a correction means, the temperature control system for cold and wherein the.