JPH0450507B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a temperature control device for a cooling area of a refrigerator or the like, and particularly relates to a temperature control device that uses a plurality of refrigerators to cool a single cooling area. It is something.

[Prior art]

Conventionally, for example, there has been a temperature control device for a refrigerator as shown in FIG. A temperature sensor 4 that detects temperature is a temperature control device that controls the temperature inside the refrigerator 1, and this temperature control device 4 includes a temperature input section 5 that takes in the temperature detected by the temperature sensor 3;
A setting unit 6 for setting the internal temperature and the number of refrigerators to be controlled, storage units 7 and 8 for storing data from these input units 5 and setting unit 6, and both storage units 7 and 8.
It is composed of a calculation unit 9 that performs calculation operations based on the data of the calculation unit 9, and a control unit 10 that operates and stops the refrigerators 2a to 2n based on the results of the calculation unit 9.
A control line 11 connects the control unit 10 and the refrigerators 2a to 2n.

Next, the operation of the conventional temperature control device configured as described above will be explained.

The internal temperature of the refrigerator 1 is inputted to the input section 5 of the temperature control device 4 by the temperature sensor 3, and is stored in the storage section 7.

On the other hand, in the setting unit 6, the number of refrigerators 2a to 2n to be controlled, the upper limit value of the internal temperature to be maintained, that is, the thermo-on point T _po , and the lower limit thermo-off point T _pff are set and stored in the same way. stored in the section. In the calculation section 9, the storage sections 7 and 8
According to the _{value of}
All units are operated to cool down and the thermo-off point is reached.
Stop when T _pff is reached. Although the temperature increases over time after the stop, the stop continues until T _po is reached, and once T _po is reached, a command is issued via the control unit 10 to start operating all the refrigerators again.

In this way, the internal temperature of refrigerator 1 becomes T _po .
It will be maintained during T _pff .

Figure 2 shows the changes in the internal temperature of the refrigerator 1 due to operation and stop of the refrigerator at this time, and ta ₁ ,
ta ₂ is the time during which the entire number of refrigerators is operated.

In the conventional temperature control device as mentioned above,
When the temperature inside the refrigerator reaches or exceeds the thermo-on point, the refrigerator is configured to operate all the refrigerators until it drops to the thermo-off point, so the balance between the refrigerator load and the refrigerator, which changes from moment to moment, is taken into consideration. Therefore, when the load is low, the temperature inside the refrigerator will drop rapidly, and depending on the item, rapid cooling may not be good for some items.

Also, if you have to open the refrigerator door for a long time when loading and unloading cargo, cooling will occur rapidly.
It stops after a short period of operation, and while it is stopped, the temperature inside the refrigerator rises due to the influence of outside air, and then all the refrigerators operate again to cool down in a short time and stop, and when it stops, it starts again. The refrigerator is frequently operated and stopped, causing the temperature inside the refrigerator to rise due to the influence of outside air.

In addition, when the load is large, it is difficult to cool the inside of the refrigerator, and the refrigerator may continue to operate for a long time without reaching the thermo-off point. Moreover, continuing cooling operation until the thermo-off point is reached will increase the amount of electricity used. There was a problem.

[Summary of the invention]

Therefore, this invention provides that if the temperature inside the refrigerator is between the thermo-on point and the thermo-off point, and cooling operation is performed for a certain period of time or more during this period, it will last for a long time even if the refrigerator is stopped, as long as the cooling area has sufficient insulation function. This was done with a focus on the fact that it is possible to keep the refrigerator cold for hours, and the number of refrigerators to be controlled, the thermo-on point T _po , the thermo-off point T _pff , and the thermo-off point T _pff after the refrigerator starts operating at the thermo-on point T _po The minimum value of the time required to stop at the thermo-on point T ₁ , the maximum allowable time t ₂ when the load does not drop below the thermo-on point T _po when the load is large after starting at an internal temperature higher than the thermo-on point T _po , the thermo-on point T _po When operating within the range _of thermo-on point T _po and thermo-off point T _pff after starting at ₃ is set in the setting section, and this determines the number of chillers that should be operated in order to quickly balance the constantly changing load in the cooling area and maintain the temperature within the setting and close to the thermo-on point. decide,
It is an object of the present invention to provide a temperature control device that reduces power consumption and saves energy.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

FIG. 3 shows an example in which the temperature control device according to the present invention is applied to a refrigerator, and the same reference numerals as in FIG. 1 indicate the same or corresponding parts. Also, 1
Reference numeral 2 denotes a temperature control device for controlling the internal temperature of the refrigerator 1, which includes a temperature input unit 5 and its storage unit 7 for inputting the temperature detected by the temperature sensor 3 into the temperature control device 12, and an upper limit temperature of the internal temperature. and a setting section 13 for setting the lower limit temperature, the number of operating refrigerators, various setting times, etc.; a storage section 14 for storing the setting data;
It is comprised of a calculation unit 15 that calculates control commands for the refrigerators 2a to 2n, and a control unit 16 that outputs control commands to the refrigerators 2a to 2n based on the calculation results obtained by the calculation unit 15.

13 is the operating setting number of refrigerators, the upper limit temperature (thermo-on point T _po ) and lower limit temperature (thermo-off point T _pff ) of the temperature to be maintained in the freezer, and the temperature in the freezer reaching the lower limit temperature from the upper limit temperature. The minimum time required for the operation is t ₁ , and the maximum operating time of the refrigerator is t ₃
and a setting unit 14 that sets and stores in the storage unit 14 a deviation allowable time t ₂ when the temperature inside the freezer becomes higher than the upper limit temperature due to the influence of load fluctuations during operation of the refrigerator; is the setting section 13
A storage unit 15 stores the temperature in the freezer from the temperature input unit 5 and each setting value from the storage unit 14, and when the temperature in the freezer is higher than the upper limit temperature, the operation setting is changed. An operation command is output to operate the refrigerator for the number of refrigerators, and the operation time of the refrigerator after the temperature inside the freezer reaches the lower limit temperature or the temperature inside the freezer reaches the upper limit temperature. When the maximum time _t3 is exceeded, a stop command is output to stop all the freezers, and if the temperature inside the freezer reaches the lower limit temperature, the temperature inside the freezer rises again. In order to reduce the number of refrigerators that are operated again from the time when the maximum temperature is reached, the operating setting number is changed, and the temperature inside the freezer is becomes higher than the upper limit temperature, and if the temperature inside the freezer does not fall below the upper limit temperature, _the refrigerator's A calculation unit 16 outputs an operation command to increase the number of operating units and changes the set number of units in operation; 16 is a calculation unit 1;
This is a control unit that receives instructions from 5 and controls the refrigerator.

Next, the operation of this embodiment configured as described above will be explained.

The temperature inside the refrigerator 1 is detected by the temperature sensor 3, and the detected temperature is input to the temperature input section 5 and stored in the storage section 7. On the other hand, the number of operating refrigerators set in the setting unit 13, the thermo-on point _Tpo ,
The thermo-off point T _pff and the time values t ₁ to _{t 3} are stored in the storage unit 14
is memorized. Therefore, when a load or temperature change occurs in the refrigerator 1, the calculation section 15 stores the storage section 7,
Based on each value of 14, the number of operating refrigerators is determined so as to balance the load of the refrigerator 1, and the control unit 16
commands are issued to each refrigerator, and the calculations are performed as follows.

Here, the temperature inside refrigerator 1 is the thermo-on point T _po
(hereinafter simply referred to as T _po ) and thermo-off point T _pff
(hereinafter referred to simply as T _pff ), and there is no need to lower it to T _pff by operating the refrigerator.

In addition, increasing the cooling temperature setting by 1 degree can save 2 to 3% of power, so keeping the temperature inside the refrigerator as close to T _po as possible will also save energy.

This will be explained below with reference to FIG. FIG. 4 shows changes in the internal temperature of the refrigerator 1 due to operation and stoppage of the refrigerator, with the horizontal axis representing time and the vertical axis representing temperature.

Now, it is assumed that there are a total of N refrigerators 2a to 2n, that the number of refrigerators set for operation is set to N, and that the temperature inside the refrigerator at a certain time is T _A. Since the internal temperature T _A at this time is higher than T _po , the calculation unit 15 issues a command to the control unit 16 to operate N units of refrigerators since the number of units to be operated is set to N units. The control unit 16 controls all the refrigerators 2a to 2n to be in operation. After the operation, the calculation unit 15 starts counting the time from the time when the temperature inside the refrigerator reaches T _po . Then, when the inside of the refrigerator is cooled down to T _pff , the refrigerator stops and the above-mentioned count also stops. Assuming that the time during this period is tb ₁ , the calculation unit 15 determines that the refrigerating capacity is excessive due to the internal load if the time t ₁ ≧ tb ₁ preset in the setting unit 13, and the next time the internal temperature is The number of refrigerators to be operated again from the time when T po increases to T _po is determined to be, for example, N-2. When t ₁ < tb ₁ , the number is N-1. That is,
Change the number of operation settings to N-1 or N-2.

The cooling operation is started from the temperature T _po in the refrigerator, and while the temperature drops to T _pff , the calculation unit 15 determines the number of refrigerators to be operated next time while comparing and determining the magnitudes of t ₁ and tb ₁ . . . tb _o . As a result, the load inside the refrigerator and the refrigeration function are balanced, and the inside of the refrigerator is cooled after operation starts at T _po , but the temperature does not drop to T _pff . That is, the calculation unit 15 compares the operating time tc ₁ from T _po with the time value t ₃ preset in the setting unit 13, and stops the refrigerator when tc ₁ ≧ t ₃ . It is. In this case, the number of refrigerators in operation next time will be the same as this time.

In this way, the time _t3 is automatically adjusted to the optimal time according to the driving time and maintained in a well-balanced state.
The operation will be performed for tc ₁ ... tc _o .

Also, if the load inside the refrigerator changes again, for example, if the load becomes smaller than it is now, the temperature inside the refrigerator will change.
Since there is a possibility that the number of chillers in operation may drop to T _pff , the calculation unit 15 may adjust the number of operating refrigerators while comparing the set time value t _{3 with the set time value t 3} . For example, t _c < t ₃
If the temperature inside the refrigerator reaches T _pff , the number of units in operation can be reduced. Note that it is assumed that t ₃ has a relationship with t ₁ such that t ₃ ≧t ₁ . If the load increases, the current number of units in operation may not be enough and the temperature inside the refrigerator may rise beyond T _po , so the calculation unit 15
Count the time td ₁ during which the refrigerator is operating at T _po or higher, compare that value with the set time value t ₂ preset in the setting section 13, and when t ₂ ≦ td ₁ , the number of operating chillers is determined. Add one machine and change the number of machines set for operation. From the time when one unit is added, time td ₂ is counted again, and when t ₂ > td ₂ , the inside of the refrigerator is cooled and the temperature becomes T _po
If the number of units in operation is used as a reference, the temperature inside the refrigerator is controlled between T _po and T _pff while comparing it with the set time value t ₃ . Moreover, if cooling is not achieved at T _po even if t ₂ ≦ td ₂ , one more refrigerator is added and the number of refrigerators set for operation is changed. In this way, the temperature inside the refrigerator 1 can be quickly adjusted to T _po.
The temperature is controlled within the range of and T _pff and closer to T _po .

In the above embodiment, the number of refrigerators to be increased or decreased during operation by the calculation unit 15 is set to 1 or 2, but it may also be possible to set the number by the setting unit 13, and the automatic adjustment time of the set time value t3 may also be set by the setting unit ₁₃ . It may also be configurable. Furthermore, although the target was a refrigerating machine that cools a refrigerator, it can also be applied to an air conditioner that air-conditions a room.

〔Effect of the invention〕

As described above, according to the present invention, the number of operating chillers, the upper limit temperature and the lower limit temperature to be maintained in the cooling area, the maximum operating time of the chiller, and the load amount during the operating of the chiller. The allowable deviation time should be set in case the temperature in the cooling area becomes higher than the upper limit temperature due to the influence of fluctuations in the cooling area. While comparing the
The size of the current load is indirectly determined and the number of operating chillers is calculated according to that load, so that the number of operating chillers can quickly follow the ever-changing load. As a result, efficient temperature control is possible with the number of units in operation always balanced with the load, and
By appropriately selecting each setting value, it is possible to control the temperature close to the upper limit temperature, which has the effect of saving energy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional temperature control device for a refrigerator, Fig. 2 is a characteristic diagram showing changes in internal temperature in the conventional refrigerator, and Fig. 3 is a block diagram showing an example of a temperature control device for a refrigerator according to the present invention. , FIG. 4 is a characteristic diagram showing the temperature change inside the refrigerator according to the present invention. 1...refrigerator, 2a-2n...freezer, 3...
Temperature sensor, 5...Temperature input section, 7...Storage section,
13...Setting section, 14...Storage section, 15...Calculation section, 16...Control section. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A temperature input section for inputting the temperature in the cooling area cooled by a plurality of refrigerators, the operating setting number of the refrigerators, the upper and lower temperature limits of the temperature to be maintained in the cooling area, and the refrigerators. a setting unit that sets the maximum operating time of the chiller and a deviation allowable time when the temperature in the cooling area becomes higher than the upper limit temperature due to the influence of load fluctuations during the operation of the chiller, and stores it in the storage unit; Then, input the temperature in the cooling area from the temperature input section and each set value from the storage section, and when the temperature in the cooling area is higher than the upper limit temperature, operate the refrigerator for the number of units set for operation. When the command is output and the temperature in the cooling area reaches the lower limit temperature or the operating time of the chiller exceeds the maximum operating time after the temperature in the cooling area reaches the upper limit temperature, the In addition to outputting a stop command to stop all refrigerators, if the temperature in that cooling area reaches the lower limit temperature, the temperature in that cooling area rises again and starts from the time when it reaches the upper limit temperature. If the number of operating chillers to be restarted is changed in order to reduce the number of operating units, and the temperature within the cooling area becomes higher than the upper limit temperature due to changes in the load amount while the chiller is operating, If the temperature within that cooling region does not subsequently fall below that upper temperature limit,
a calculation unit that outputs an operation command to increase the number of operating chillers and changes the set number of units to be operated each time the deviation allowable time elapses after the upper limit temperature is exceeded; A temperature control device comprising: a control unit that receives instructions from a controller and controls the refrigerator.