JPH0660781B2 - Defrost control system for refrigerator - Google Patents

Description

Description: [Object of the Invention] (Field of Industrial Application) The present invention relates to a defrosting control system for a refrigerator that controls execution timing of a defrosting operation according to various conditions.

(Prior Art) Conventionally, in a refrigerator, a compressor of a refrigeration cycle is turned on / off in accordance with a temperature inside the refrigerator, and thus the inside of the refrigerator is cooled to a predetermined temperature by a cooler of the refrigeration cycle. During this cooling operation, the compressor on time is integrated and when the integrated value reaches the preset defrosting reference cycle, the compressor is turned off and the heater for heating the cooler is energized. Defrost operation is performed.

(Problems to be Solved by the Invention) By the way, when performing the defrosting operation, it is important that the temperature inside the refrigerator does not rise at the end of the defrosting operation. However, in the conventional system, since the defrosting operation is uniquely executed when the integrated value of the compressor on time reaches the defrosting reference cycle, the refrigerator door is frequently opened and closed, etc. Even when the temperature is rising, the defrosting operation may be performed, and as a result, the temperature inside the refrigerator rises excessively, which adversely affects food storage. In particular, such a defect may be identified to some extent during the day when the refrigerator door is opened and closed frequently and the temperature inside the refrigerator rises due to the user's habitual usage. It occurs when the band and the defrosting execution timing match.

The present invention has been made in view of the above circumstances, and an object thereof is to perform a defrosting operation, the defrosting operation can be performed at a time when the internal temperature does not rise, and thus the food It is to provide a defrost control system for a refrigerator that can minimize the adverse effects of the above.

[Structure of the Invention] (Means for Solving Problems) The present invention relates to a compressor drive control means for turning on / off a compressor based on a temperature in a refrigerator, a compressor on-time integrating means for integrating a compressor on-time, Average temperature calculating means for calculating the average cold storage temperature in the set unit time and the average cold storage temperature in one day, and a memory in which the average cold storage temperature in the unit time is tabulated every time the unit time passes. Storage means for sequentially moving and storing the unit time, and the average unit internal temperature of the unit time stored 24 hours before and 23 hours before the present time is smaller than the average daily internal temperature and the average unit time at the present time. If the internal cold storage temperature is lower than the average daily internal cold storage temperature and the current compressor on-time integrated value is within the preset range for the preset defrost reference cycle Turns on the defrost heater turns off the Tsu support by defrosting completion detecting input are those formed by and a defrosting operation control means for turning off the defrost heater.

(Operation) While the compressor is turned on / off according to the internal temperature, the compressor on time is integrated by the compressor on time integration means. In addition, the average temperature calculating means calculates the average internal temperature in the set unit time and 1
The daily average temperature in the refrigerator is calculated. Then, each time the unit time elapses, the average in-compartment temperature in the unit time is sequentially moved and stored in the table-formed memory. Therefore, when the refrigerator has been used for more than one day, the memory stores the average internal temperature of the refrigerator for each unit time.

Thus, the defrosting operation control means is configured such that the average cold storage temperature in the unit time stored 24 hours and 23 hours before the current time is smaller than the average cold storage temperature in one day and the current unit time is When the average cold storage temperature is less than the daily average cold storage temperature and the current compressor on-time integrated value is within the set range for the defrost reference cycle, the compressor is turned on and the defrost heater is turned on. Then, the defrosting operation is started, the defrosting heater is turned off by the defrosting end detection input, and the defrosting operation is ended. That is, when the average cold storage temperature of a unit time stored 24 hours ago (at the same time on the previous day) and 23 hours ago (1 hour after the same time on the previous day) is smaller than the average cold storage temperature of the day, With this, it is determined that the internal cold storage temperature after one hour from the present time will be low, and when the average internal cold storage temperature per unit time at present is lower than the average daily temperature, the internal cold storage temperature is still low. Also, when the integrated value of the compressor on time is within the set range with respect to the defrosting reference cycle, it is determined that this is the time when the amount of frost on the cooler has increased. When these judgment results are obtained, it is the time to execute the defrosting operation, and even if it is executed, the inside temperature does not rise due to opening and closing of the door during the execution, and the inside temperature becomes excessive at the end time. It judges that it will not rise and starts defrosting operation.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1, reference numeral 1 denotes a control circuit composed of a microcomputer, which also serves as a compressor drive control means, a compressor on-time integration means, an average temperature calculation means, a storage means, and a defrosting operation control means. Reference numeral 2 denotes a freezer compartment temperature determination circuit, which is configured to have a temperature sensor 3 for detecting the inside compartment temperature, for example, the freezer compartment temperature, and a comparator 4, etc.
When the temperature exceeds 5 ° C., the high-level upper limit temperature detection signal Sfo is output. The input terminal A ₁ of this output control circuit ₁
Given to. Reference numeral 5 denotes a defrosting end temperature determination circuit, which has a temperature sensor 6 for detecting the temperature of the cooler, a comparator 7, and the like. The defrosting end temperature determination circuit 5 outputs a high-level defrosting end detection signal Sjs and gives it to the input terminal A ₃ of the control circuit 1 when the cooler temperature becomes, for example, + 10 ° C. or higher. Reference numeral 8 denotes an inside temperature detection circuit having a temperature sensor 9 for detecting the inside temperature of the refrigerator, for example, the temperature of the refrigerating room, which supplies temperature data Tm corresponding to the temperature to the input terminal A ₂ of the control circuit 1. Further, the input terminal ₄ of the control circuit 1 is provided with outside temperature detection data Rt (° C.) corresponding to the outside temperature (room temperature) from an outside temperature detecting circuit (not shown). 10 is a compressor drive circuit, which is a relay coil 11 and this relay coil 1
A relay switch (not shown) which is turned on by 1 to energize a compressor (not shown), and a relay coil 11
It is configured to have a transistor 12 that cuts off electricity. The transistor 12 is an output terminal C ₁ of the control circuit _1.
Is turned on by the high-level compressor-on signal Sco from. Reference numeral 13 denotes a defrost heater driving circuit, which cuts off the relay coil 14, a relay switch (not shown) which is turned on by the relay coil 14 to energize the defrost heater (not shown), and the relay coil 14. It is configured by including a transistor 15 for charging. The defrost heater is provided to heat a cooler (not shown),
The transistor 12 is turned on by the high-level compressor-on signal Sco from the output terminal C ₂ of the control circuit 1. Reference numeral 16 is a reset circuit.

Now, the control circuit 1 has an operation control program, and its flowchart is shown in FIG. The parameter C in this program is a count value that is also used for the number of times the temperature inside the refrigerator is measured and the time (minutes), T is the integrated value of the temperature inside the refrigerator (° C), Ton is the compressor on-time count value (minutes) per unit time, and Std is A count value (hour) that is an integrated value of the compressor on-time, Crt is a count value for the number of times of outside air temperature measurement, Srt is an integrated value of the outside air temperature (° C), Art is an average value of the outside air temperature (° C), and Tdp is the compressor on-time integration It is a defrosting reference cycle (hour) for the value. Further, the flag D is a determination flag for determining whether or not the defrosting operation is being executed. In addition, the control circuit 1 includes a memory area Mr1 which is tabulated in 24 stages in the memory.
To Mr24 are secured. In addition to this, a memory area Mr25 for storing the average daily inside temperature and a memory area Mr26 for storing the average internal temperature at the current unit time are secured.

The control function of the control circuit 1 will be described below with reference to FIG. When the power is turned on, first, in step S ₁ (subroutine), the above-described parameters and flags D are cleared, and the memory areas Mr1 to Mr24 are also cleared.
Each content value of is set to an initial value of 3 ° C. In step S ₂ , the upper limit temperature detection signal Sfo is output from the freezer compartment temperature determination circuit 2.
Input there is determined whether made of, if there is an input, outputs a compressor ON signal Sco and (compressor ON) counts up the compressor on-time count value Ton in step S ₄ in step S _3, and step to migrate to S _6. If the signal Sfo is not input in step S ₂ , the compressor-on signal Sc is output in step S _5.
The output of o is stopped and the process proceeds to step S ₆ . And performs a wait of step S ₆ 1 minute, which is performed in the subroutine of software timers. Incidentally, the gist of "wait a minute" is the step _{S 4,} step _{S 14,}
This is because the time counted in S _{20 is performed} in units of 1 minute, and the execution time of the other steps is extremely short, so the time count in step S ₄ etc. is in units of approximately 1 minute. The next step S ₇ in the compressor on-time count value T
Judge whether on has passed 240 minutes, that is, 4 hours,
If it has not elapsed, the process returns to step S ₂ . The 240 minutes, that is, 4 hours is an initial value of the defrosting reference cycle for the first defrosting operation after the power is turned on, and the purpose of the 4 hours is as follows. That is, normally, the defrosting reference cycle is set to "8 hours" or "12 hours", but when there is a power failure, the integrated value of the compressor on time is cleared, so after the power is turned on (after the power failure is restored). Has a substantially intermediate value of "4 hours" as an initial value. Then, part 4
Over time, the process proceeds to step S ₈ stops outputting the compressor ON signal Sco output defrosting heater ON signal Sho Step S ₉ with (compressor OFF) (defrost heater on) to start the defrosting operation . This defrosting operation is the first defrosting operation after the power is turned on. And Thus, as can be seen from the steps S ₁₀ and step S _11, the defrosting completion detecting signal from the defrosting completion temperature sensing circuit 5 Sj
s input is the (determination in step _{S 10),} and stops the output of the defrosting heater ON signal Sho (step _{S 11),} and terminates the defrosting operation.

Now, when this first defrosting operation ends, the defrosting control system functions for the second and subsequent defrosting operations. First,
In step S _12, the standby one minute is performed, and in step S _13, reads the internal temperature data Tm from the inside temperature detection circuit 8. Then, the counts up the count value C in step _{S 14,} step S
_{At 15} , the in-compartment temperature integrated value T is integrated based on the in-compartment temperature data Tm. Next Step In S ₁₆ the count value C (inside temperature measurement number and time count value) "60"
That it is determined whether or not more than 60 minutes, the process proceeds to step S ₁₇ does not exceed. The flag D is "1" whether or not the input of the upper limit temperature detection signal Sfo proceeds to (defrosting operation execution state) unless the step S ₁₈ that there determination in step S _17, if the input , The compressor is turned on (step S ₁₉ ), the compressor on-time count value Ton is counted up (step S ₂₀ ), the process returns to step S ₁₂ , and if the upper limit temperature detection signal Sfo is not input, the compressor is turned off (step S ₂₀ ). ₂₁ ) and returns to step S ₁₂ . Also, step S
If the flag D is "1" in the ₁₇ (running defrosting operation), the transition to the defrosting completion temperature determination circuit 5 whether input defrosting end detection signal Sjs there decision in step S ₂₂ and, if there is input, outputs the compressor on signal Sco at step S _23, the process returns to step S ₁₂ to the fractionator D to "0", step S if there is no input
₂₃ does not execute and returns to step S ₁₂ .

Now, when the time count value C has passed the 60 minutes (1 hour), and determines whether or not the flag D is "1", the process proceeds from step S ₁₆ to step S _24, if it is "0" (if not running defrosting operation), and executes the steps _{S 25} to S _{S 28} sequentially. This step _{S 25} to _{S 28} are intended to be executed in order to calculate the ambient temperature mean value Art, namely, to measure the ambient temperature at read step _{S 25} the outside air temperature data Rt, measured in step _{S 26} The count value Crt of the number of times is counted up, the outside air temperature integrated value Srt is calculated in step S ₂₇ , and the outside air temperature average value Art is calculated in step S ₂₈ . Then, when the outside air temperature average value Art is lower than 18 ° C., the process goes from step S ₂₉ to step S ₃₀ and the defrosting reference cycle Tdp is set to “12 hours”, and the outside air temperature average value is 18 ℃ in step S ₃₁ if more defrosting reference period T
Set dp to "8 hours".

And Thus, dividing the defrosting reference period Tdp is set to one in step S ₃₀ or step S _31, the process proceeds to step S _32, the previous compressor ON time i.e. the compressor on-time count value Ton per time unit Is converted to “hour” units and the compressor on-time integrated value St
Count up d. Thereafter, the process proceeds to step _{S 34} to clear the Ton in step _{S 33.}

In this step _S34 , the average internal temperature (T / 60) in the last hour is calculated, and the average internal temperature (T / 6) is calculated.
0) is stored in the memory area Mr26. Then, Step mean-compartment temperature in the _{S 35} 24 hours That day {(Mr1 + Mr2 + ... Mr24 ) / 24} calculated by the stores the average in-compartment temperature to the memory area MR 25. Next, at step S _36, and clears the count value C and the interior temperature integrated value T, and proceeds to step S _37.

In step _{S 37,} the memory area Mr1 and Mr
Both of the content values of 2 are smaller than the content value of the memory area Mr25 and the current memory area Mr26 is present.
When the content value of small and compressor on-time integrated value than the content value of the MR 25 Std is in the range of defrosting reference period Tdp ± 2, the step S ₃₈ and step S
₃₉ run in sequence proceeds to step _{S 40.} The output of the step S ₃₈ in the compressor ON signal Sco stopped (compressor OFF), in step S _39, and outputs a defrosting heater ON signal Sho starts defrosting operation,
Further, the flag D is set to "1", and the count value Crt and the integrated values Srt and Std are set to "0", respectively. Further, in step S _37, the process proceeds to step S ₄₁ to be satisfied in one of the conditions, determines whether or not the integrated value of the compressor on-time Std exceeds 2 hours defrosting reference period Tdp Then, if it exceeds, the process proceeds to step S ₃₈ described above, and if it does not exceed, the process directly proceeds to step S ₄₀ (without starting the defrosting operation). Incidentally, in the above step _{S 24,} if the flag D is "1" (running defrosting operation), the step _{S 42} and step S
₄₃ perform the (aforementioned steps _{S 34} and step _{S 36} and each same content), outside air temperature measurement or the like does not execute, the process proceeds to step _{S 40.}

In step _{S 40} each of the memory areas Mr1, Mr
2, ... The content values of Mr23 and Mr24 are sequentially moved to the upper memory area and stored. Since this step S ₄₀ 1 hour in a step S ₁₆ in is made on condition that it has passed, the mobile storage every hour is performed. Memory areas M with an average in-compartment temperature (previous step _{S 34} or step _{S 42} in the next step _S in ₄₄ here 1 hour
r26 temperature) stored in the stored in the memory area MR 24, and proceeds to step _{S 17.}

Thus, the memory area Mr at the bottom of the memory after the first hour has passed.
The average internal temperature (T /
Since 60) is stored, when 24 hours or more have passed after the power was turned on, at the time when step _S37 is executed, the average temperature inside the refrigerator for one hour 24 hours before is stored in the uppermost memory area Mr1. Has been done. Therefore, the stored content values 24 hours ago and 23 hours ago (memory areas Mr1 and Mr
If each stored average storage temperature of 2) is smaller than the content value of the memory area Mr25 (average storage temperature of one day), it is determined that the storage temperature will not rise for one hour from the present time. Similarly, at the present time, the average internal temperature (Mr26
Is the average temperature of the inside of the room (content value of Mr25)
If it is smaller than this, it is determined that the internal cold storage temperature is kept low at this point. Furthermore, the integrated value Std for the compressor on time is set to the reference defrost cycle Tdp in a setting range (Tdp-2 ≦ Std ≦ T.
The main purpose of determining whether or not it is in dp + 2) is that there is no problem even if the defrosting operation is started in this time zone. And Thus, if these determination results satisfied all in step S _37, a time to be defrosted, rather than the temperature rise due to opening and closing of the door during the run to run and refrigerator at that end it is determined that the internal temperature will not be excessively increased, the step as described above S ₃₈ and step S ₃₉
To start defrosting operation. Therefore, when the defrosting operation is executed, the internal temperature rise can be minimized, and the adverse effect on the food can be reduced.

[Effects of the Invention] As is apparent from the above description, the present invention relates to the result of the average temperature in the cold storage that is sequentially stored for each unit time when starting the defrosting operation, and the average temperature in the cold storage for the current unit time. And the average daily inside temperature, it is possible to determine the time when the temperature does not rise, and the defrosting operation is executed based on the result of the time determination. It has an excellent effect that the rise can be minimized and the adverse effect on food can be reduced.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an electric circuit diagram,
FIG. 2 is a flowchart of the control program. In the figure, 1 is a control circuit (compressor drive control means, compressor on-time integration means, average temperature calculation means, storage means, defrosting operation control means), 2 is a freezer compartment temperature determination circuit, 5
Is a defrosting end temperature determination circuit, 8 is an internal temperature detection circuit, 10
Is a compressor drive circuit, and 13 is a defrost heater drive circuit.

Claims (1)

[Claims] 1. A compressor is turned on based on the internal temperature.
Compressor drive control means for turning off, compressor on-time integrating means for integrating the compressor on-time, average temperature calculating means for calculating the average cold storage temperature in a set unit time and the average cold storage temperature in one day, A storage unit that sequentially moves and stores the average in-compartment temperature of the unit time in the table-formed memory every time the unit time elapses, and the average in-compartment temperature of the unit time stored 24 hours and 23 hours before the present time. The temperature is lower than the average cold storage temperature in one day, the average cold storage temperature per unit time at the current time is lower than the average cold storage temperature in the day, and the current compressor on-time integrated value is preset. Defrost operation control that turns off the compressor, turns on the defrost heater, and turns off the defrost heater by the defrost end detection input when the defrosting reference cycle is within the set range. Refrigerator defrost control system comprising and means.