JPH0758149B2 - Cooling control device for refrigerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control rule of a rapid cooling control device based on an empirical rule for cooling foods and the like to an appropriate temperature in a short time, and a membership function of fuzzy variables constituting the control rule. The present invention relates to a quenching control device for a refrigerator in which the optimum operation amounts of a quenching fan and a compressor are inferred by and the results are output.

2. Description of the Related Art Refrigerators (including refrigerators / freezers) have a basic function of storing foods and the like, but in recent years, those with additional functions have begun to appear. One of the additional functions is rapid refrigeration (hereinafter abbreviated as rapid cooling). This rapid cooling function cools the food until it reaches an appropriate temperature as needed, and can be used, for example, when "I want to quickly cool beer with a sudden customer" or "I want to eat a salad with a quick cooling", It has the advantage of being able to preserve the freshness of foods as they are at a speed.

In a conventional quenching control device for a refrigerator, for example, JP-A-63-118
There is a method as shown in Japanese Patent No. 584. Here, when the rapid cooling is started by a rapid cooling command (for example, switch-on), the damper is always opened for a preset time, and the fan continuously sends the cool air to the rapid cooling chamber. However, in such a method of controlling the rapid cooling operation only depending on time, there is a problem that, for example, a beer bottle bursts due to supercooling, or other foods freeze and their quality deteriorates. In order to solve this supercooling, there is a method disclosed in, for example, JP-A-63-189760. That is, in the rapid cooling state, the damper is used to set the temperature of the quenching chamber to a temperature lower than usual, and the internal cool air is forcedly circulated using the fan to cool the food,
Non-contact the surface temperature of the food (eg infrared sensor)
The rapid cooling operation was stopped when the surface temperature cooled to a certain temperature.

However, in such a configuration, since the cooling is always performed with a constant cooling capacity during the rapid cooling, for example, even if the rapid cooling operation is stopped at the target surface temperature, the cooling proceeds further with the aftereffect. The temperature will be lower than the target temperature (generally called overshoot). Moreover, since the temperature control is only performed after the completion of the rapid cooling, the temperature once lowered does not return to the normal temperature. In this case, the worst condition such as bursting of the beer bottle can be avoided, but since the supercooling still occurs and the low temperature condition continues for a while, there is a risk that the food is frozen and the quality is deteriorated. Further, since the temperature of the food is lower than the optimum temperature, the flavor and taste of the food are impaired.
To prevent this, for example, the target surface temperature may be set higher, but in this case, insufficient cooling will occur, and only the surface will be cold and the contents will not be cold. There was a problem that the flavor and taste would be impaired.

In view of the above problems, the present invention provides a quenching control device for a refrigerator that does not deteriorate the quality such as freezing of food, does not impair the flavor and taste of food, and can reach a target temperature in a short time. The purpose is to

Means for Solving the Problems In order to achieve the above object, the quenching control device for a refrigerator of the present invention is a quenching chamber provided in a part of the refrigerator, a quenching fan for sending air to the quenching chamber, and Food temperature detecting means for detecting the temperature of food or the like placed in the quenching chamber, differentiating means for outputting the amount of change in the output of the food temperature detecting means, and output of the food temperature detecting means and output of the differentiating means For information, a memory device that stores a control rule based on an empirical rule for obtaining the operation amount of the quenching fan and the compressor, information of the output of the food temperature detecting means and the output of the differentiating means, and the memory device. Fuzzy inference means for performing a fuzzy logic operation based on the extracted control rule to calculate the operation amounts of the quenching fan and the compressor, and the quenching flow by the output of the fuzzy inference means. A quenching fan control means for controlling the fan and a rotation speed control means for controlling the rotation speed of the compressor are provided.

Action According to the above configuration, the operation amount of the quenching fan and the compressor with respect to the food temperature detected by the food temperature detecting means and the change amount thereof is calculated based on the control rule obtained from the empirical rule. The state of the food being processed, for example, when the cooling is about to start or just before the cooling is finished, is optimized by the cooling fan and compressor so that the food can always be cooled with the optimum cooling capacity. It is possible to prevent overcooling and undercooling. Further, since the temperature of the cooling air from the evaporator can be controlled by controlling the rotation speed of the compressor, the food can be cooled in a very short period of time.

Embodiment A quenching control device for a refrigerator according to an embodiment of the present invention will be described below with reference to the drawings.

First, the schematic structure of the present invention will be described with reference to FIG. FIG. 2 is a sectional view of the refrigerator of the present invention. In FIG. 2, reference numeral 1 denotes a refrigerator main body, which is composed of an outer box 2, an inner box 3 and a urethane foam heat insulating material 4 formed in a space between them.
Three doors 5, 6, 7 are arranged in the front opening.
The doors 5, 6, and 7 are arranged corresponding to the openings of the freezer compartment 8, the refrigerator compartment 9, and the vegetable compartment 10 of the refrigerator body 1, respectively.
Inside the partition wall surrounded by the bottom plate 11 of the freezer compartment 8 and the top plate 12 of the refrigerating compartment 9, there is an evaporator 13 and an internal fan 14 behind it. Further, ventilation paths 15 and 16 for introducing cooling air from the evaporator 13 into the respective compartments are formed at the backs of the freezing compartment 8 and the refrigerating compartment 9. 17 is a compressor. Reference numeral 18 is a quenching room provided below the refrigerating room 9. The quenching chamber 18 is separated from the refrigerating chamber 9 by a wall 19, and a door 20 is arranged at the opening thereof. An air passage 21 for introducing cold air from the evaporator 13 into the quench chamber 18 is formed on the back surface of the quench chamber 18.

The configuration of the quenching device in the refrigerator thus configured will be described in more detail with reference to FIG. First
FIG. 1 is a block diagram of a quenching control device for a refrigerator according to the present invention. In FIG. 1, reference numeral 22 is a damper for introducing or blocking cold air from the ventilation passage 21. Reference numeral 23 is a quenching fan for introducing cold air into the quenching chamber 18. The cool air referred to here includes the first cool air supplied through the ventilation passage 21 and the damper 22, and the second cool air supplied through the ventilation hole 24 provided at the rear portion of the top surface of the wall 19. The first cold air is cold air whose temperature changes depending on the rotation speed of the compressor 17, and the second cold air is cold air of about 5 ° C. Reference numeral 25 is a food temperature sensor for detecting the surface temperature of the food 26. 27 is a food temperature detecting means for detecting the surface temperature T of the food 26 from the output of the food temperature sensor 25. 28 differentiates the output of the food temperature detecting means 27 and changes the surface temperature of the food 26 by ΔT (that is, ΔT = T).
It is a differentiating means for calculating (t + Δt) −T (t)).
Further, 29 is a microprocessor, which comprises a fuzzy inference means 30 and a memory device 31 for storing control rules. Reference numeral 32 is a quenching fan control means for controlling the capacity (that is, the number of revolutions) of the quenching fan 23 according to the instruction of the operation amount obtained by the fuzzy inference means 30. Reference numeral 33 is a rotation speed control means for controlling the capacity (that is, the rotation speed) of the compressor 17 in accordance with the operation amount instruction obtained by the fuzzy inference means 30. 34 is the quenching room 18
It is a quenching room temperature sensor that detects the temperature inside. 35
Is a quenching chamber temperature detecting means for calculating the temperature of the quenching chamber 18 based on a signal from the quenching chamber temperature sensor 34. Reference numeral 36 is a damper control means for controlling the opening / closing of the damper 22 according to the output of the quenching room temperature detection means 35.

The operation of the quenching control device for a refrigerator configured as described above will be described below with reference to FIGS.

The food temperature detecting means 27 detects the surface temperature T of the food 26 from the output of the food temperature sensor 25, and the differentiating means 28 differentiates the output of the food temperature detecting means 27 to change the surface temperature of the food 26 ΔT (that is, ΔT). = T (t + Δt) −T (t), where t represents time and Δt represents time change.
The surface temperature T and the variation ΔT of the surface temperature calculated as described above are input to the fuzzy inference means 30. Memory device
Reference numeral 31 stores a control rule necessary for fuzzy inference executed by the fuzzy inference means 30. Fuzzy inference for obtaining the capacity (that is, the rotation speed) that is the operation amount of the quenching fan 23 and the capacity (that is, the rotation speed) that is the operation amount of the compressor 17 is executed based on the following control rules.

The control rules adopted in this embodiment are the following nine rules. For example, rule R1: if the temperature is high and the amount of temperature change is large, make the quench fan extremely strong and the rotation speed of the compressor very large.Rule R2: if the temperature is low and the amount of temperature change is large For example, weaken the quench fan and standardize the compressor speed. The language rule is a control rule for the control of the quenching fan and the compressor most suitable for the food to be cooled rapidly, which is obtained from the empirical rule obtained by the inventor from a large number of experimental data. The relationships are shown in Tables 1 and 2. Tables 1 and 2 show the relationship of the control rules for the quenching fan and the compressor used in each example.

Tables 1 and 2 show the temperature T in three levels (LT
= Low temperature, MT = appropriate temperature, HT = high temperature), and three levels (NB = negative, ZO = zero,) in the vertical direction according to the strength of the temperature change amount ΔT.
Table 1 shows the optimum cooling fan capacity for the strength of the temperature T and the amount of temperature change ΔT at the position where each of the temperature T and the amount of temperature change ΔT intersects. The rotation speed of the compressor is set in Table 2. Here, in Table 1, the capability of the quenching fan is divided into five levels according to the strength (VS = very strong, S = strong, M = medium, W =
Weak, VW = very weak), and in Table 2, the number of revolutions of the compressor is divided into three stages (N = standard, F = large, VF = very large). That is, the control rule Ri (i = 1,
2, ... 9) are shown as squares (Ri) in Tables 1 and 2. The inventor of the present invention has experimentally confirmed according to Tables 1 and 2 that optimum quenching control can be realized when the capacity of the quenching fan and the rotation speed of the compressor are controlled.

When the language rules are stored in the memory device 31 shown in FIG. 1, they are stored according to the following rule rules. The number of control rules used in the present invention is nine.

Rule R1: IF T is HT and ΔT is PB THEN F ＝ VS and C
= VF Rule R2: IF T is LT and ΔT is PB THEN F ＝ W and C
= N ... Next, the fuzzy inference means 30 takes out the control rule stored in advance in the memory device 31 and uses fuzzy inference to determine the operation amount of the quenching fan 23 and the compressor 17
The cooling fan control means 32
Output to the rotation speed control means 33. The quenching fan control means 32 controls the capacity of the quenching fan 23 according to the determined operation amount, and the rotation speed control means 33 controls the rotation speed of the compressor 17 according to the determined operation amount.

The rules of the control rules R1, R2 ... R9 are the ability of the quenching fan 23 for the temperature T and the temperature change amount ΔT,
Since the number of revolutions of the compressor 17 is determined stepwise, when performing fine control, the degree to which the antecedent part (IF part) of the control rule is satisfied is calculated, and Capacity of quenching fan 23, compressor 17 according to degree
It is necessary to estimate the rotation speed of. Therefore, in this embodiment, a membership function of fuzzy variables is used to calculate the degree.

FIG. 3 (a) shows fuzzy variables LT, MT, HT with respect to temperature T.
Membership functions of μLT (T), μMT (T), μHT
FIG. 3B shows the membership functions μPB (ΔT), μZO (ΔT), μNB (ΔT) of the fuzzy variables PB, ZO, and NB with respect to the temperature change amount ΔT. It is a thing.

The fuzzy inference executed by the fuzzy inference means 30 is the control rule 1, rule 2, ... Rule 9 and FIG.
A fuzzy logic operation is performed using the membership function (b) and the operation amount is calculated. As the inference method, the max-min method was used for the synthesis method, and the height method was used for the-pointing method. The inference procedure will be described below with reference to FIG. FIG. 4 is a flow chart showing the inference procedure. In STEP 1, food temperature detection means 2
7. The differentiating means 28 calculates the temperature To and the temperature change amount ΔTo. S
In TEP2, the fuzzy reasoning means 30 calculates the membership value at the temperature To and the temperature change amount ΔTo by using the membership function of the fuzzy variable for the temperature To and the temperature change amount ΔTo. In STEP3, the degree to which the obtained membership value is the antecedent part of each of the nine rules is calculated by the synthesis method (in FIG. 4, the fuzzy variable for temperature is A, and the fuzzy variable for temperature change is fuzzy). Variables are indicated by B).

Rule R1: h1 = μHT (To) ∩μPB (ΔTo) = MIN {μHT (To). μPB (ΔTo)} −− (1) Rule R2: h2 = μLT (To) ∩μPB (ΔTo) = MIN {μLT (To). μPB (ΔTo)} −− (2) ··· (1) In the equation (1), the To falls within the region HT corresponding to the temperature T, and the ΔTo falls within the region PB corresponding to the temperature change amount ΔT.
The proposition of entering is to be satisfied at the ratio of To entering HT and ΔTo entering PB as a smaller value, and therefore the antecedent in the case of rule 1 is satisfied at the ratio of h1. ing. Similarly, in the case of rule 2 which is the expression (2),
It means that the antecedent part holds at the rate of h2. STEP
In Step 4, the operation amount of the quenching fan and the compressor at the temperature To and the temperature change amount ΔT is obtained by the membership function of the execution unit of the control rule as follows. In order to obtain the operation amount Fo of the quenching fan and the operation amount Co of the compressor, the constants in the conclusion part are given as the weighted average by h1, h2 ... h9 Fo = (VS × h1 + W × h2 + ・ × h9) / (h1 ＋ h2 ＋ ・ ・ ・
・ ＋ h9) Co ＝ (VF × h1 ＋ N × h2 ＋ ・ ・ × h9) / (h1 ＋ h2 ＋ ・ ・ ・
・ + H9) The height method, which is one of the one-point methods, collects the operation amount Fo of the quenching fan and the operation amount CO of the compressor to control the quenching fan.
32 and the rotation speed control means 33.

Next, an example of the rapid cooling operation when this embodiment is applied will be described with reference to FIG. FIG. 5 is a timing chart showing an example of the rapid cooling operation of this embodiment. 5 (a) is a quenching fan 23, FIG. 5 (b) is a compressor 17, and FIG. 5 (c).
Shows the change of the surface temperature of the food 26 with respect to time, the solid line shows the case of the present embodiment, and the broken line shows the case of the conventional example. In the conventional rapid cooling control, the rapid cooling fan 23 is turned on until the food surface temperature reaches the target temperature (in this case, 5 ° C.) (point A), so the surface temperature continues to drop with the aftereffect even after the rapid cooling is stopped. Overshoot below (point B). After that the temperature gradually recovers,
The target temperature is reached after a while (point C). In the case of the quenching control of this embodiment, when the initial surface temperature is high (dual point), the quenching fan 23 is made very strong and the compressor is
By making the number of rotations of 17 very large, the food can be cooled more rapidly than before. And the quenching fan that is most suitable for the surface temperature of food and the amount of change in surface temperature
23. By controlling the compressor 17 (point E), the target temperature can be reached earlier than before (point F), and temperature overshoot can be suppressed (point G). In addition, even if the food surface temperature becomes too cold, as shown in Table 1, the quenching fan 23 is controlled.
Since the cool air (about 5 ° C.) in the refrigerating room can be taken in through the ventilation hole 24, the target temperature can be reached quickly even if supercooling occurs.

Therefore, in this embodiment, since the surface temperature of the food 26 and the amount of change in the surface temperature are used as the control parameters, fine control can be performed on the food that is desired to be cooled rapidly. Further, since the control rule is based on human experience, it is possible to control the quenching control device with the optimum capacity of the quenching fan 23 and the rotation speed of the compressor 17. Therefore, the food can always be cooled with the optimum cooling capacity, so that the target temperature can be reached quickly, overcooling and undercooling can be prevented, and deterioration of food quality can be prevented. In addition, by providing the ventilation hole 24, even in the unlikely event of overcooling, or even if food with a low temperature is put in, it is possible to circulate the cold air in the refrigerating room, so it is also quick against overcooling. The target temperature can be reached.
In addition, because the surface temperature of the food 26 is detected and automatically controlled, there is no need to provide a rapid cooling switch, etc., so the rapid cooling operation is performed automatically, so insufficient rapid cooling due to human error (forgot to switch on, weight setting There will be no mistakes, etc., and it will also lead to cost reduction.

Incidentally, in the embodiment, in order to detect the food temperature, an infrared sensor was used, but not limited to this, for example, the information that can be correlated with the surface temperature of the food such as the ambient temperature of the quenching room and the temperature of the return duct of the cool air. You may use.

Effects of the Invention As described above, the quenching control device for a refrigerator of the present invention is a quenching chamber provided in a part of the refrigerator, a quenching fan for sending air to the quenching chamber, and a food item placed in the quenching chamber. Food temperature detecting means for detecting the temperature such as, a differentiating means for outputting the amount of change in the output of the food temperature detecting means, and the information of the output of the food temperature detecting means and the output of the differentiating means,
A memory device for storing a control rule based on an empirical rule for obtaining the operation amounts of the quenching fan and the compressor, information on the output of the food temperature detecting means and the output of the differentiating means, and the control extracted from the memory device. A fuzzy inference means for performing a fuzzy logic operation based on a rule to calculate an operation amount of the quenching fan and the compressor, a quenching fan control means for controlling the quenching fan by an output of the fuzzy inference means, and a compressor. By providing a rotation speed control means for controlling the rotation speed of the, the operation amount of the quenching fan and the compressor with respect to the food temperature detected by the food temperature detection means and its change amount, based on the control rule obtained from empirical rules. Calculate the optimum cooling rate according to the state of the food being rapidly cooled, for example, when the rapid cooling begins or just before the end of the rapid cooling. And to perform in the compressor, is always it is possible to cool the food in an optimal cooling capacity, it is possible to prevent excessive cooling or cooling shortage, it is possible to very short time of the food cooling.

[Brief description of drawings]

FIG. 1 is a block diagram of a refrigerator quenching control apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of a refrigerator according to an embodiment of the present invention, and FIG. 3 (a) is a fuzzy variable LT with respect to temperature T, M
A characteristic diagram showing the membership functions of T and HT, and FIG. 3 (b) is a fuzzy variable PB, ZO for temperature change amount ΔT,
FIG. 4 is a characteristic diagram showing the membership function of the NB, FIG. 4 is a flow chart showing the inference procedure, FIG. 5 is a timing chart showing an example of the quenching operation of this embodiment, and FIG. Timing chart showing operation, FIG. 5 (b)
Is a timing chart showing the operation of the compressor, and FIG. 5 (c) is a timing chart of the food surface temperature. 18 ... Quenching room, 23 ... Quenching fan, 27 ... Food temperature detecting means, 28 ... Differentiating means, 30 ... Fuzzy inference means, 31 ...
... Memory device, 32 ... quenching fan control means, 33 ... rotation speed control means.

Claims (1)

[Claims] 1. A quenching chamber provided in a part of a refrigerator, a quenching fan for sending air to the quenching chamber, and a food temperature detecting means for detecting the temperature of food or the like placed in the quenching chamber. Differentiating means for outputting the amount of change in the output of the food temperature detecting means, and the empirical rule for obtaining the operation amount of the quenching fan and the compressor with respect to the information of the output of the food temperature detecting means and the output of the differentiating means. Based on the information of the output of the food temperature detecting means and the output of the differentiating means and the control rule extracted from the memory device, the quenching fan and the aforesaid quenching fan. A fuzzy inference means for calculating an operation amount with a compressor, a quenching fan control means for controlling the quenching fan based on an output of the fuzzy inference means, and a circuit for controlling a rotation speed of the compressor. Refrigerator quench control device, characterized in that it comprises a number control unit.