JPH04302977A - Control method of refrigerator with freezer - Google Patents

Abstract

PURPOSE:To perform delicate temperature controls of a refrigerator with a freezer where food is frozen and stored, and solve such a problem that optimum control can not be performed when food is loaded full or fast cooling is required because of unexpected visitors in the summer season, for example. CONSTITUTION:An ambient temperature arithmetic device 29 is provided to calculate the change degree of the ambient temperature of a freezing compartment from the compartment inside temperature, etc. A thermal load arithmetic device 31 is provided to calculate the thermal load amount of food on each shelf in the freezing compartment from the temperature of each shelf, etc. A fuzzy reasoning processor 33 performs fuzzy reasoning according to the change degree of ambient temperature, etc., and a control rule taken out from a memory 32. A damper controller 34 controls the opening degree of dampers provided on shelves according to the calculated result, and a fan motor controller 35 drives a fan.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention utilizes a control rule based on empirical rules and membership functions of fuzzy variables constituting the control rule to store frozen food in a freezer compartment for a long period of time and maintain freshness. The present invention relates to a control device for a refrigerator-freezer that infers the amount of operation of a damper and the amount of operation of a fan motor, and outputs the results.

0002

[Prior Art] A refrigerator-freezer control device is a refrigerator-freezer (
It controls the damper, fan motor, and compressor so that the temperature of the freezer compartment, refrigerator compartment, and vegetable compartment of the refrigerator (hereinafter abbreviated as refrigerator) is controlled at a set temperature (for example,
Utility Model Application Publication No. 2-47424).

[0003] Hereinafter, with reference to the drawings, a conventional control device for a refrigerator-freezer will be explained, particularly temperature control of a freezer compartment.

FIG. 6 shows a block diagram of a conventional refrigerator-freezer control device. In FIG. 6, reference numeral 1 denotes a refrigerator body, which is composed of an outer box 2, an inner box 3, and a urethane foam insulation material 4 formed in the gap between the two, and has three doors 5, 6, and 7 arranged at the front opening. ing. Doors 5, 6, and 7 are the freezer compartment 8, refrigerator compartment 9, and vegetable compartment 10 of the refrigerator body 1, respectively.
It is arranged corresponding to the opening of.

Bottom plate 11 of freezer compartment 8 and top plate 12 of refrigerator compartment 9
There is an evaporator 13 and a fan 14 behind it in the partition wall surrounded by. Furthermore, ventilation passages 15 and 16 are formed at the backs of the freezer compartment 8 and the refrigerator compartment 9 for introducing cooling air from the evaporator 13 into each compartment. 17 is a compressor. 18 is a freezer compartment door switch operated by opening and closing the door 5 of the freezer compartment 8, and 19 is a freezer compartment temperature sensor. 24 is a fan motor that drives the fan 14.

Further, 25 is a door opening/closing detection means for detecting the opening/closing of the door 5 of the freezer compartment 8 from the operation of the freezer compartment door switch 18, and 28 is a door opening/closing detection means for detecting the internal temperature of the freezer compartment by a freezer compartment temperature sensor 19. This is an internal temperature detection means. 36
is an arithmetic means for calculating the operating amount of the fan motor and the operating amount of the compressor from the internal temperature detected by the internal temperature detecting means 28.

Reference numeral 35 denotes a fan motor control means for controlling the fan motor 24 and driving the fan 14 from the operation amount of the fan motor, and 37 is a compressor control means for driving the compressor 17 from the operation amount of the compressor.

The operation of the refrigerator-freezer control device configured as above will be explained below with reference to FIGS. 6 and 7.

FIG. 7 is a flowchart for explaining conventional temperature control of the freezer compartment 8. First, the door opening/closing detection means 25 detects whether the freezer compartment 8
It is determined whether the door 5 is closed (S
step 21). If the door 5 is closed, the refrigerator internal temperature detection means 28 detects the refrigerator internal temperature Tfc in the freezer compartment by the freezer compartment temperature sensor 19 (Step 22). Then, the calculating means 36 calculates the operating amount m of the fan motor and the operating amount f of the compressor based on the internal temperature Tfc (Step 2
3).

The fan motor control means 35 drives the fan 14 by controlling the fan motor 24 based on the operation amount m of the fan motor, and the compressor control means 37 drives the fan 14 based on the operation amount f of the compressor. 17 (Step 24). From the above, freezer compartment 8
Controls the temperature of the freezer compartment by blowing cold air at the appropriate temperature. Furthermore, if the door 5 is open, the fan 14 is stopped (S
step 25).

[0011]

However, in the above configuration, the control amount m of the fan motor and the control amount f of the compressor are calculated based only on the information of the internal temperature Tfc detected by the internal temperature detection means 28. Because of this, it was not possible to precisely control the temperature, for example in the summer.
The problem is that it is not possible to control the temperature optimally when you want to quickly cool down food when you are packing food or when you suddenly have guests.

The present invention solves the above problems.
Refrigeration that allows fine-grained temperature control by calculating the amount of heat load (hereinafter abbreviated as "load amount") of food on each shelf in the freezer compartment and the operating amount according to changes in the ambient temperature inside the refrigerator. The purpose is to provide a control device for a refrigerator.

[0013]

[Means for Solving the Problems] In order to achieve the above object, the refrigerator-freezer control device of the present invention provides a refrigerator-freezer equipped with a freezer compartment in which food can be frozen and stored.
A freezer compartment door switch operated by opening and closing of the freezer compartment door, a door opening/closing detection means for detecting opening/closing of the freezer compartment door from the operation of the freezing compartment door switch, and a timer counter, and a door opening time calculation means for calculating a door opening time based on an output signal; an outside air temperature sensor provided outside the refrigerator-freezer; and an outside temperature detection means for detecting the outside air temperature outside the refrigerator-freezer using the outside air temperature sensor. A freezer temperature sensor provided for each shelf in the freezer compartment, an internal temperature detection means for detecting the temperature of each shelf in the freezer compartment by the freezer compartment temperature sensor, and a door calculated by the door open time calculation means. The degree of change in ambient temperature of the freezer compartment is calculated from the open time, the outside temperature detected by the outside temperature detection means, and the temperature of each shelf in the freezer compartment detected by the inside temperature detection means. a calculation means, a differentiating means for determining the rate of temperature change for each shelf based on the output of the internal temperature detecting means, and a differentiating means for determining the rate of temperature change for each shelf based on the output of the internal temperature detecting means; A heat load calculating means is provided for calculating the amount of food heat load (food temperature x heat capacity) for each shelf in the freezer compartment from the rate of temperature change for each shelf, and a means for calculating the heat load is provided for each shelf in the freezer compartment to send cold air. a damper, a memory that stores control rules based on empirical rules for determining the operation amount of the damper and the operation amount of the fan motor, and the amount of heat load for each shelf calculated by the heat load calculation means and the ambient temperature. a fuzzy inference processor that performs fuzzy logic operations to calculate the operation amount of the damper and the operation amount of the fan motor based on the degree of change in ambient temperature of the freezer compartment calculated by the calculation means of the freezer and the control rule retrieved from the memory; , comprising a damper control means for controlling the opening degree of the damper for each shelf based on the damper operation amount and the fan motor operation amount calculated by the fuzzy inference processor, and a fan motor control means for controlling the fan motor. The configuration is as follows.

[0014]

[Operation] With the above configuration, the present invention calculates the load amount for each shelf calculated by the heat load (hereinafter abbreviated as load) calculation means and the atmospheric temperature change degree of the freezer compartment calculated by the atmospheric temperature calculation means. Based on the control rule retrieved from the memory, a fuzzy logic operation is performed by a fuzzy inference processor to determine the amount of operation of the damper and the amount of operation of the fan motor. Therefore, based on the operation amount determined above, the opening degree of the damper is controlled for each shelf, and the fan is driven by controlling the fan motor, so that optimal temperature control of the freezer compartment can be performed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator/freezer control device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a control device for a refrigerator-freezer in an embodiment of the present invention, and FIG. 2(a) shows membership of fuzzy variables for the load on the first shelf in a freezer compartment in an embodiment of the present invention. Graph showing the function, FIG. 2(b) is a graph showing the membership function of fuzzy variables with respect to the load on the second shelf in the freezing room in the embodiment of the present invention, FIG. 2(c) is the embodiment of the present invention FIG. 3 is a flowchart for explaining the operation in the embodiment of the present invention, and FIG. 4 is a graph showing the relationship between door opening/closing time and ambient temperature in the embodiment of the present invention. FIG. 5 is a flowchart for explaining the fuzzy inference procedure in the embodiment of the present invention.

In FIG. 1, 22 and 23 each represent 1
It is a damper for the first shelf and the second shelf, and by changing the opening degree,
Adjust the amount of cooling air supplied to the first shelf and the second shelf, respectively. Reference numeral 26 denotes a door opening time calculation means, which calculates the door opening time based on the signal output from the door opening/closing detection means 25. Reference numeral 27 denotes an outside air temperature detection means, which uses the outside air temperature sensor 21 to detect the outside air temperature outside the refrigerator. Further, 28 is an internal temperature detection means, which detects the temperature of the first shelf in the freezer compartment by a freezer compartment temperature sensor A19,
The temperature of the second shelf in the freezer compartment is detected by the freezer compartment temperature sensor B20. 29 is an atmospheric temperature calculation means;
The door open time calculated by the door open time calculation means 26, the outside air temperature detected by the outside air temperature detection means 27, and the first and second shelves in the freezer compartment detected by the inside temperature detection means 28. The degree of atmospheric temperature change in the freezer compartment is calculated from the temperature.

Reference numeral 30 denotes a differentiating means, which differentiates the output from the internal temperature detecting means 28 to determine the rate of temperature change of the first and second shelves in the freezer compartment. 31 is a load calculating means, which calculates the temperature of the first and second shelves detected by the internal temperature detection means 28 and the temperature change of the first and second shelves determined by the differentiating means 30. The amount of food loaded (food temperature x heat capacity) on the first and second shelves in the freezer compartment is calculated from the ratio.

A memory 32 stores control rules based on empirical rules for determining the amount of operation of the damper and the amount of operation of the fan motor. 33 is a fuzzy inference processor which calculates the loads on the first and second shelves calculated by the load calculating means 31, the degree of change in the ambient temperature of the freezer compartment calculated by the atmospheric temperature calculating means 29, A fuzzy logic operation is performed based on the control rule retrieved from the memory 32 to calculate the amount of operation of the damper and the amount of operation of the fan motor.

Further, 34 is a damper control means, which controls the damper A22 of the first shelf in the freezer compartment based on the operation amount of the damper.
and controls the opening degree of the damper B23 on the second shelf.

The operation of the refrigerator-freezer control device configured as described above will be explained below with reference to FIGS. 1 to 5.

First, the door opening/closing detection means 25 determines whether the door 5 of the freezer compartment 8 is closed based on the operation of the freezer compartment door switch 18 (Step 1), and if the door 5 is closed, the outside air temperature is The detection means 27 detects the outside air temperature Tout outside the refrigerator by the outside air temperature sensor 21 (
Step 2), the refrigerator temperature detection means 28 detects the temperature Tfc10 of the first shelf in the freezer compartment using the freezer compartment temperature sensor A19.
2 in the freezer compartment by the freezer compartment temperature sensor B20.
The temperature Tfc20 of the shelf of the tier is detected (Step 3).

When the door 5 is opened, the door opening time calculating means 26 starts a timer counter in the door opening time calculating means 26 in order to calculate the door opening time based on the signal from the door opening/closing detecting means 25. (Step 4
), the fan 14 is stopped (Step 5). At this time,
Food is put in and taken out of the freezer compartment 8, and outside air flows into the room (Step 6).

Next, when the door 5 is closed (Step 7
), the door opening time calculation means 26 stops the timer counter (Step 8), and calculates the door opening time H from this timer counter (Step 9). Further, the internal temperature detection means 28 detects the temperature Tfc10 of the first shelf detected by the freezer compartment temperature sensor A19 and the freezer compartment temperature sensor B20.
The temperature Tfc20 of the second shelf detected is averaged with the temperature Tfc20 of the second shelf, and the average internal temperature Tfc0 is calculated as shown in (Equation 1) (Step 10).

[0025]

[Math 1]

Then, the ambient temperature calculating means 29 calculates the door opening time H calculated by the door opening time calculating means 26.
and the outside air temperature T detected by the outside air temperature detection means 27.
out and the average internal temperature Tfc0 calculated by the internal temperature detection means 28, the atmospheric temperature change degree D of the freezer compartment is calculated.
is calculated (Step 11). Here, as the door opening time increases, the ambient temperature of the food inside the refrigerator increases, and the relationship between the door opening time and the ambient temperature is a characteristic curve as shown in Figure 4. Food ambient temperature Ti
n is found, and the degree of atmospheric temperature change D is

002
7]

[Math 2]

It is determined by: Furthermore, the internal temperature detection means 28 detects the temperature Tfc1 of the first shelf by the freezer compartment temperature sensor A19, and detects the temperature Tfc2 of the second shelf by the freezer compartment temperature sensor B20 (Step 12),
The differentiating means 30 differentiates the output from the internal temperature detecting means 28 as shown in (Equation 3), and calculates the temperature change rate ΔT of the first shelf.
Find the temperature change rate △Tfc2 of fc1 and the second shelf (
Step 13).

[0029]

[Math 3]

Then, the load calculating means 31 calculates the temperature Tfc1 of the first shelf detected by the internal temperature detecting means 28.
and the temperature change rate ΔTfc1 of the first shelf obtained by the differentiating means 27, the load amount W1 of food on the first shelf in the freezer compartment is calculated, and the temperature Tfc2 of the second shelf is similarly calculated. The food load W2 on the second shelf in the freezer compartment is calculated from the temperature change rate ΔTfc2 on the second shelf (Step 1
4).

Next, the calculated load amount W1 and load amount W
2 and the atmospheric temperature change degree D are input to the fuzzy inference processor 33 (Step 15). The fuzzy inference processor 33 takes out the control rules stored in the memory 32 in advance, and uses fuzzy inference to determine the operation amount v1 of the damper on the first shelf in the freezer compartment and the operation amount v2 of the damper on the second shelf in the freezer compartment. Calculate the operation amount m of the fan motor (
Step 16). Then, the damper control means 34 controls the opening degree of the damper A22 based on the operation amount v1 of the damper A,
The opening degree of the damper B23 is controlled based on the operation amount v2 of the damper B, and the fan motor control means 35 drives the fan 14 by controlling the fan motor 24 based on the operation amount m of the fan motor (Step 17). .

[0032] Here, the fuzzy inference for determining the amount of operation of the damper and the amount of operation of the fan motor for optimal temperature control of the freezing compartment is executed based on the following control rules.

The control rules adopted in this embodiment are the following 27 rules. For example, Rule 1: If the load on the first shelf is large, the load on the second shelf is also large, and the degree of atmospheric temperature change is large, the opening degree of the damper on the first shelf is increased, The opening degree of the damper on the tier shelf is also increased to increase the rotation speed of the fan motor.

Rule 2: If the load on the first shelf is normal, the load on the second shelf is also normal, and the atmospheric temperature change is normal, then the load on the first shelf is normal. Set the damper opening degree to medium, set the damper of the second shelf to medium opening degree, and set the fan motor rotation speed to medium speed.

Rule 3: If the load on the first shelf is small, the load on the second shelf is also small, and the degree of atmospheric temperature change is small, reduce the opening degree of the damper on the first shelf. ,2
The opening degree of the damper on the second shelf is also reduced, and the rotation speed of the fan motor is reduced.・ ・ ・ etc.

This is because if the load on a certain shelf is large or the degree of atmospheric temperature change is large, it is necessary to send a large amount of cold air to that shelf to cool it. This is a rule learned from experience, such as the need to make the motor rotate faster. Therefore, the above linguistic rule is a control rule for the damper operation amount and the fan motor operation amount that can perform optimal temperature control of the freezer compartment, which the inventor found from a large amount of experimental data, and this is the control rule for the amount of operation of the damper and the operation amount of the fan motor that can perform optimal temperature control of the freezer compartment. The relationship between W1, load amount W2, and atmospheric temperature change degree D is as shown in Table 1.

[0037]

[Table 1]

(Table 1) is a table showing the relationship between control rules, in which the load amount W1 in the horizontal direction is set in three stages (LW=high, MW=medium, SW=small), and the load amount W2 is set in three stages (LW= Multi, MW=
The atmospheric temperature change degree D is divided into three stages (LD=large, MD=medium, SD=small) in the vertical direction, and the load amount W1 and the load amount W2 are divided into three stages (LD=large, MD=medium, SD=small). At each intersection of the load amount W1, the load amount W2, and the ambient temperature change degree D, the optimal operation of the dampers of the first and second shelves in the freezing chamber is performed. The amount and operation amount of the fan motor are arranged.

[0039] Furthermore, the above language rules are stored in the memory 32 of FIG.
When it is stored within , it is stored according to the following rules. The number of control rules adopted in this example is 27.

Rule 1: IF W1 is
LWand W2 is LW and Dis LD THEN V1 is L V2 is L M is H Rule 2: IF W1 is MWan
d W2 is MW and Dis MD THEN V1 is M V2 is M M is M Rule 3: IF W1 is SWan
d W2 is SW and Dis SD THEN V1 is S V2 is S M is L ・ ・ ・ The control rule 1, rule 2...The rule of rule 27 is the load amount W1, the load amount W2, and the atmospheric temperature change degree D , the operation amount V1 of damper A, the operation amount V2 of damper B, and the operation amount M of the fan motor are determined in stages as shown in (Table 1), so when performing detailed control, load amount W1 ，
Actual load amount w1, load amount w2, and ambient temperature change degree d in the middle of each stage of load amount W2, ambient temperature change degree D
Now, calculate the degree to which the antecedent part (IF part) of the control rule is satisfied, and set the operation amount v1 of damper A, the operation amount v2 of damper B, and the operation amount of the fan motor according to the degree. It is necessary to estimate m. Therefore, in this embodiment, the degree is calculated using membership functions of fuzzy variables for the load amount W1, the load amount W2, and the degree of change in ambient temperature D.

FIG. 2(a) shows the membership function μSW(w
1), μMW(w1), μLW(w1), and FIG. 2(b) shows the membership function μSW(w2) of the fuzzy variables SW, MW, and LW for the load amount W2,
It shows μMW (w2) and μLW (w2),
FIG. 2(c) shows the membership function μSD(d) of the fuzzy variables SD, MD, and LD for the degree of atmospheric temperature change D,
μMD (d) and μLD (d) are shown. The fuzzy inference executed by the fuzzy inference processor 33 is based on the control rule 1, rule 2, . . . rule 27 and FIG. 2(a).
, (b), and (c) are used to perform fuzzy logic operations to calculate the manipulated variable.

The fuzzy inference procedure, which is Step 16 in FIG. 3, will be explained below based on the flowchart in FIG.

In Step 18, the fuzzy inference processor 33 uses the membership functions of the fuzzy variables for the load w10, the load w20, and the atmospheric temperature change d0 to determine the members at the load w10, the load w20, and the atmospheric temperature change d0. The ship value (indicated as M value in the figure) is calculated.

[0044] In Step 19, the obtained load amount w10
, the degree to which the membership values of the fuzzy variables with respect to the load amount w20 and the degree of atmospheric temperature change d0 satisfy the antecedent part of each of the 27 rules is calculated by the synthesis method as follows.

In the figure, the fuzzy variable for the load on the first shelf in the freezer compartment is indicated by A, the fuzzy variable for the load on the second shelf is indicated by B, and the fuzzy variable for the degree of atmospheric temperature change is indicated by C. There is.

Rule 1: h1=μLW(w10)∩μLW(w2
0)∩μLD(d0)=MIN{μLW(w10),μ
LW (w20), μLD (d0)} ---(1)
Rule 2: h2=μMW(w10)∩μMW(w20
)∩μMD(d0)=MIN{μMW(w10),μM
W(w20), μMD(d0)} ---(2)
Rule 3: h3=μSW(w10)∩μSW(w20)
∩μSD(d0)=MIN{μSW(w10),μSW
(w20), μSD(d0)} ---(3)... Equation (1) indicates that the w10 is the area LW for the load amount W1.
and the w20 is the area L for the load amount W2.
The proposition that d0 falls within the range LD for the atmospheric temperature change degree D is determined by the ratio of w10 entering LW, w20 entering LW, and d0 entering LD, whichever is the smaller value. This means that the antecedent part of rule 1 is satisfied at a rate of h1. Similarly, in the case of Rule 2 and Rule 3, which are equations (2) and (3), the antecedent parts are satisfied at a rate of h2 and h3, respectively.

In Step 20, the load amount w10 and the load amount w2 are determined by the membership function of the execution part of the control rule.
The operation amount of the damper A, the operation amount of the damper B, and the operation amount of the fan motor at the atmospheric temperature change degree d0 and the atmospheric temperature change degree d0 are determined as follows. The operation amount v10 of the damper A, the operation amount v20 of the damper B, and the operation amount m0 of the fan motor are calculated using the maximum height method, which is one of the single point methods, and the ratio h1 of the antecedent part of each control rule is satisfied. The value of the consequent of the control rule having the maximum height hi among h2, . . . h27 is calculated as follows.

v10=V1(max{h1, h2,..., h27}
)v20=V2(max{h1,h2,...,h27
}) m0 = M (max{h1, h2,..., h2
7}) As a result, the operation amount v10 of damper A and damper B
The operation amount v20 of the fan motor and the operation amount m0 of the fan motor are determined.

Therefore, in this embodiment, since the load on the first shelf in the freezer compartment, the load on the second shelf, and the degree of change in ambient temperature are used as control parameters, fine-grained control is possible. It is. Furthermore, since the control rules are based on human experience, it is possible to control the temperature of the freezer compartment with the optimal amount of damper operation and fan motor operation.

[0050] In this embodiment, the freezer compartment has two shelves, but the number of shelves may be increased and each shelf may be provided with a temperature sensor and a damper for control. It is.

[0051]

As described above, the present invention provides a refrigerator-freezer equipped with a freezer compartment in which food can be frozen and stored, and a freezer compartment door switch that is operated by opening and closing the freezer compartment door, and a freezer door switch that operates by opening and closing the freezer compartment door. door opening/closing detection means for detecting opening/closing of the door of the freezer compartment from the operation of a switch; door opening time calculation means having a built-in timer counter and calculating the door opening time based on a signal output from the door opening/closing detection means;
an outside air temperature sensor provided outside the refrigerator-freezer, an outside air temperature detection means for detecting the outside air temperature outside the refrigerator-freezer using the outside air temperature sensor, a freezer room temperature sensor provided for each shelf in the freezer compartment, an internal temperature detection means for detecting the temperature of each shelf in the freezer compartment by a room temperature sensor; a door opening time calculated by the door opening time calculation means; an outside air temperature detected by the outside air temperature detection means; an atmospheric temperature calculation means for calculating the degree of change in the ambient temperature of the freezer compartment from the temperature of each shelf in the freezer compartment detected by the interior temperature detection means; A differentiating means for determining the rate of change, a temperature of each shelf detected by the internal temperature detecting means, and a temperature change rate for each shelf determined by the differentiating means to calculate the heat of food on each shelf in the freezer compartment. Experience in calculating the heat load calculation means to calculate the load amount (food temperature x heat capacity), the damper installed on each shelf in the freezer compartment to send cold air, and the amount of operation of the damper and the amount of operation of the fan motor. a memory for storing a control rule based on the above-mentioned heat load calculation means, a heat load amount for each shelf calculated by the heat load calculation means, a degree of change in the ambient temperature of the freezer compartment calculated by the atmospheric temperature calculation means, and the memory; a fuzzy inference processor that performs fuzzy logic operations to calculate the damper operation amount and the fan motor operation amount based on the control rules extracted from the control rules; and the damper operation amount and fan motor operation calculated by the fuzzy inference processor. By providing a damper control means for controlling the opening degree of the damper for each shelf and a fan motor control means for controlling the fan motor, it is possible to store frozen foods in the freezer compartment freshly for a long period of time. In particular, since the opening degree of the damper is controlled for each shelf in the freezer compartment, the temperature of the freezer compartment can be finely controlled for each shelf. For example, when a large amount of food is packed in the summer when the outside air temperature is high, quick freezing can be performed with the amount of operation depending on the food load on each shelf. In addition, since the temperature is controlled by the amount of operation according to the food load on each shelf, no more energy than necessary is consumed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control device for a refrigerator-freezer showing an embodiment of the present invention.

[Fig. 2] (a) is a graph showing the membership function of fuzzy variables with respect to the load on the first shelf in the same embodiment; (b) is a graph showing the membership function of the fuzzy variable with respect to the load on the second shelf in the same embodiment; Graph (c) showing the membership function is a graph showing the membership function of fuzzy variables with respect to the degree of change in ambient temperature in the same example.

[Fig. 3] Flowchart for explaining the operation in the same embodiment.

[Figure 4] Graph showing the relationship between door opening/closing time and ambient temperature in the same example

[Fig. 5] Flowchart for explaining the procedure of fuzzy inference in the same embodiment.

[Figure 6] Block diagram of a conventional refrigerator-freezer control device

[Fig. 7] Flowchart for explaining the operation in the conventional example

[Explanation of symbols]

8 Freezer room 18 Freezer door switch 19 Freezer room temperature sensor A 20 Freezer room temperature sensor B 21 Outside air temperature sensor 22 Damper A 23 Damper B 25 Door opening/closing detection means 26 Door opening time calculation means 27 Outside air temperature detection means 28 Internal temperature detection means 29 Ambient temperature calculation means 30 Differential means 31 Heat load calculation means 32 Memory 33 Fuzzy inference processor 34 Damper control means 35 Fan motor control means

Claims (1)

[Claims] 1. In a refrigerator-freezer equipped with a freezer compartment capable of freezing and storing food, there is provided a freezer compartment door switch that is operated by opening and closing the freezer compartment door, and a freezer compartment door switch that is operated by opening and closing the freezer compartment door; door opening/closing detection means for detecting the opening/closing of the refrigerator; door opening time calculation means having a built-in timer counter and calculating the door opening time based on the signal output from the door opening/closing detection means; a sensor, an outside air temperature detection means for detecting the outside air temperature outside the refrigerator-freezer using the outside air temperature sensor, a freezing room temperature sensor provided for each shelf in the freezing room, and a freezing room temperature sensor provided for each shelf in the freezing room using the freezing room temperature sensor a door opening time calculated by the door opening time calculation means, an outside air temperature detected by the outside air temperature detection means, and a door opening time calculated by the door opening time calculation means; an atmospheric temperature calculating means for calculating the degree of change in ambient temperature of the freezing compartment from the temperature of each shelf in the freezing compartment; a differentiating means for calculating the rate of temperature change for each shelf from the output of the internal temperature detecting means; From the temperature of each shelf detected by the internal temperature detection means and the temperature change rate of each shelf determined by the differentiating means, the amount of heat load (food temperature x heat capacity) of the food on each shelf in the freezer compartment is calculated. A memory that stores a means for calculating the heat load, a damper installed on each shelf in the freezer compartment to send cold air, and control rules based on empirical rules for determining the amount of operation of the damper and the amount of operation of the fan motor. Based on the heat load amount for each shelf calculated by the heat load calculation means, the degree of change in the ambient temperature of the freezer compartment calculated by the atmosphere temperature calculation means, and the control rule retrieved from the memory. , a fuzzy inference processor that performs fuzzy logical operations to calculate the damper operation amount and the fan motor operation amount, and a damper operation amount for each shelf based on the damper operation amount and the fan motor operation amount calculated by the fuzzy inference processor. 1. A control device for a refrigerator-freezer, comprising: a damper control means for controlling the opening degree of the refrigerator; and a fan motor control means for controlling the fan motor.