JPH0534043A - Ice making machine and method for controlling ice making machine with fuzzy inference - Google Patents

Abstract

PURPOSE:To perform an ice removing operation at a proper temperature by a method wherein in the case that a temperature of a cooler in an ice making means reaches a set temperature so as to complete an ice removing step, a fuzzy inference wherein each of variation values based on a surrounding air temperature and an ice removing water temperature being applied as an input variable is used for determining the set temperature and the like. CONSTITUTION:An ice making machine 1 is constructed such that recessed parts 4 and protruding parts 5 are alternately formed in an ice making member 3 having an ice making surface 3A for forming ice blocks 2. A cooling pipe 6 is arranged at a rear surfaces of the recessed parts 4. An ice making water dispersion device 13 is disposed above the ice making member 3 and this is connected to a circulation pump 17 disposed at a water storing tank 16. An ice removing water dispersion device having some water dispersion holes 20A is disposed at an upper part of the rear surface of the ice making member 3 and it is connected to a water suction valve 21. As the temperature of the cooling pipe 6 reaches an ice removing completion sensing temperature, the ice removing stage is completed In this case, determination of the ice removing completion sensing temperature is carried out in reference to a fuzzy deduction with each of the values varying in response to the surrounding air temperature and the ice removing water temperature being applied as an input variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice making machine, and in particular,
The present invention relates to an ice maker and a control method thereof for determining a defrosting completion detection temperature by fuzzy reasoning.

[0002]

2. Description of the Related Art Conventionally, in this type of ice making machine, as shown in, for example, Japanese Unexamined Patent Publication No. 1-200168, ice making water is circulated on an ice making surface which is a surface of an ice making member having a cooling pipe of a refrigeration cycle on the back side. Then, the ice lumps are allowed to grow, and the grown ice lumps are caused to flow hot gas through the cooling pipe, and the ice water for supplying ice is flowed from the water supply solenoid valve to the back surface to remove ice, and the ice water is stored in the water storage tank for the next ice making. It is configured to be used as water.

The ice making machine executes the above cycle of repeating the ice making process and the ice removing process. In particular, in order to end the ice making process, conventionally, the temperature at the refrigerant outlet side of the cooling pipe is detected by the outlet temperature sensor. However, when the temperature there rises and reaches a certain ice-off completion detection temperature such as + 8 ° C., the hot gas flow is terminated.

[0004]

As described above, the conventional control system has various problems described below because the deicing completion detection temperature is fixed regardless of the outside air temperature and the deicing water temperature. It was That is, FIG. 8 shows the time transition of the refrigerant outlet side temperature ET of the cooling pipe in the case of low outside air temperature, FIG. 9 shows the time transition of the refrigerant outlet side temperature ET of the cooling pipe in the case of medium outside air temperature, and FIG. The time transition of the refrigerant outlet side temperature ET of the cooling pipe when the outside air temperature is high is shown respectively.

When the outside air temperature is low, the temperatures of the equipment and piping that make up the refrigeration cycle of the ice making machine are also low, so even if hot gas begins to flow from the start of ice removal in FIG. The rising rate of the refrigerant outlet side temperature ET is slow. However, since ice-breaking water is also made to flow on the back side of the ice-making member, the temperature of the ice-making member also rises and the temperature ET becomes +8, especially when the temperature of the ice-breaking water is high.
Long before the temperature reached ℃, the ice block finished falling. Therefore,
As compared with the inside / outside temperature in FIG. 9, there is a problem that the useless period from the end of the ice block drop to the end of the hot gas becomes longer, the cycle time becomes longer, and the ice making capacity is lowered.

On the other hand, when the outside air temperature is high, the temperature of the equipment and piping constituting the refrigeration cycle of the ice making machine is also high. Therefore, when hot gas is started to flow through the cooling pipe from the start of ice removal in FIG. 10, The temperature ET on the refrigerant outlet side of the cooling pipe rises rapidly. Therefore, of the ice blocks, the part close to the cooling pipe is rapidly separated from the ice-making member, but the other parts are not separated, and the ice blocks are not easily removed despite the rapid increase in the temperature ET. No, temperature ET as shown in FIG.
Often ends just before the temperature reaches + 8 ° C, especially when the temperature of the ice-free water flowing on the back side of the ice making member is low, there is a risk that the ice block will not end falling even when the hot gas ends. .

According to the present invention, by solving the above problems and appropriately determining the ice-free completion detection temperature by fuzzy reasoning,
An object of the present invention is to provide an ice maker and a control method thereof, which have completed ice removal at an appropriate temperature and have improved ice making ability and achieved reliable ice removal.

[0008]

An ice making machine of the present invention comprises an ice making means equipped with a cooler, an ice removing means, a water supplying means for supplying ice removing water, and an ice making process for forming ice blocks by the ice making means. Alternately repeat the deicing process to separate the ice blocks from the ice making device by the deicing device, and supply the deicing water to the ice making device by the water supply device during the deicing process, so that the temperature of the cooler is a predetermined deicing temperature. A control means for terminating the deicing process when the completion detection temperature is reached, and a value that changes based on the outside air temperature and a value that changes based on the temperature of the deicing water when determining the deicing completion detection temperature in this control means. It uses fuzzy inference with the input variable as.

Further, in the method for controlling an ice making machine according to the present invention, the outside air temperature is used as the first input variable, and the temperature of the ice-free water is used as the second input variable. After determining the membership value according to both input variables from the ship function, fuzzy combining the output variables of the inference rule, and obtaining the inference result by taking the center of gravity of the output variable to determine the deicing completion detection temperature. It is used for.

[0010]

According to the present invention, the deicing completion detection temperature can be accurately determined with respect to changes in the outside air temperature around the ice making machine and the supplied deicing water temperature, and quick and stable deicing can be performed. it can.

[0011]

Embodiments Next, embodiments will be described with reference to the drawings. FIG. 1 is a block diagram of a control device C as a control means of the ice making machine 1 of the present invention, and FIG. 2 is a system configuration diagram of the ice making machine 1, FIG.
FIG. 3 is a perspective view of a main part of the ice making machine 1. 2 and 3, the ice making machine 1 is a flow-down type ice making machine for producing a large number of independent ice blocks 2, and the ice making members 3 and 3 as an ice making means having an ice making surface 3A on the surface are stainless plates. A plurality of recesses 4 and protrusions 5 that extend in the horizontal direction are formed alternately by bending, and the back surfaces of the ice-making members 3 and 3 are joined to each other with their back surfaces facing each other and spaced apart. On the back side, a cooling pipe 6 as a cooler formed in a meandering shape is provided with a recess 4
Is arranged in contact with the back surface of the.

That is, the vertical portion 6A of the cooling pipe 6 having a predetermined space has a cross relationship with the concave portion 4 and the convex portion 5,
A portion corresponding to the back surface of the inner recess 4 is fixed to the back surface of the recess 4 by soldering or the like, and the bend portion 6B of the cooling pipe 6 is spaced from the back surface of the projection 5 without contacting the back surface of the recess 4. To face each other. The cooling pipe 6 is annularly connected together with the electric compressor 7, the condenser 9, the capillary tube 10 and the like to form a refrigeration cycle, and an additional device is a bypass pipe 11 that bypasses the condenser 9.
And a hot gas solenoid valve 12 connected to the bypass pipe 11.
Is equipped with. Further, the condenser 9 is forcibly cooled by the blower 8.

Next, the water system will be described. The upper end of one ice making member 3 covers the upper end of the other ice making member 3 to form an upper water guide portion 14. The upper water guide portion 1
4 is provided with an ice making water sprinkler 13 and a large number of water sprinkling holes 13A for allowing ice making water to flow down to the ice making surface 3A via a water guide portion 14 are formed at predetermined intervals in the longitudinal direction thereof. There is. Water conduit 15 extending from the end of this sprinkler 13.
Is connected to a circulation pump 17 arranged in the water storage tank 16. The water sprinkler 13 and the circulation pump 17 constitute a water sprinkler. Further, the water storage tank 16 is in communication with a trough 19 that collects unfrozen water that has dropped from the lower water guide portions 18, 18 at the lower end of the convex portion 5.

On the other hand, an ice sprinkler 20 is disposed above the back surface of the ice making surface 3A, and the ice making surface 3A is provided in the longitudinal direction thereof.
A large number of water spray holes 20A for spraying the ice-free water are formed at predetermined intervals on the back surface of the. This sprinkler 20 is connected to a water pipe via a water supply solenoid valve 21 as a water supply means. Further, in FIG. 1, the control device C is basically composed of a control unit 25 composed of a microcomputer, and an input of the control unit 25 is an outlet temperature sensor 26 attached to a refrigerant outlet side portion of the cooling pipe 6. The output, the output of the outside air temperature sensor 28 attached to the refrigerant outlet side portion of the condenser 9, and the output of the water temperature sensor 29 attached to the sprinkler 20 are input, and the output is the electric compressor 7 and the circulation pump 17. The pump motor 17M, the hot gas solenoid valve 12, the blower 8 and the water supply solenoid valve 21 are connected.

Next, the control operation of the controller C will be described.
When the power is first turned on, the control unit 25 controls the water supply solenoid valve 21.
Is opened to start the water supply operation to the water storage tank 16. In this case, from the water spray hole 20A of the ice water sprayer 20 to the ice making surface 3A,
Water sprinkled on the upper part of the back surface of 3A is the back surface of the concave portion 4
When it flows down along the back surface of the water tank, falls from the lower guide portion 18 into the trough 19, and the fixed amount of water is supplied to the water storage tank 16, the water supply solenoid valve 2
1 is closed and the water supply operation is completed.

Simultaneously with the end of the water supply operation, the electric compressor 7 is started, the low temperature refrigerant is circulated in the cooling pipe 6, and at the same time, the motor 17M of the circulation pump 17 is operated to start the ice making operation. The ice making water in the water storage tank 16 is pressure-fed to the ice making water sprinkler 13 through the water conduit 15 by the operation of the circulation pump 17, and the ice making water sprinkled from the water sprinkling holes 13A of the water sprinkler 13 to the upper water guide portion 14 is , Flow down the ice making surface 3A. The ice making water flowing down the ice making surface 3A falls from the lower water guide portion 18 to the trough 19, is returned to the water storage tank 16, and is circulated again to the ice making surface 3A.

At this time, since the ice making water flows down along the vertical portion 6A of the cooling pipe 6, the temperature of the ice making water gradually decreases as the temperature of the cooling pipe 6 decreases in the process of repeating this circulation. When the ice making operation is further continued, the ice block 2 further grows. When this ice making operation is continuously performed for a predetermined time and a predetermined ice block 2 is formed in the concave portion 4,
While the electric compressor 7 is operating, only the blower 8 is stopped, and at the same time, the circulation pump 17 is also stopped to end the ice making process.

When the ice making operation is completed by such control, the control unit 25 opens the hot gas electromagnetic valve 12 and passes through the bypass pipe 11, and the high temperature and high pressure refrigerant gas (hot gas) from the electric compressor 7 in operation. To the cooling pipe 6,
The ice making member 3 is heated to start the ice removing operation. At the same time, the water supply solenoid valve 21 is also opened to spray ice-free water for a predetermined time from the water spray holes 20A of the ice sprayer 20 to the back sides of the ice making surfaces 3A and 3A. The ice removing water flows on the back surface of the concave portion 4 and the back surface of the convex portion 5, and together with the heating by the hot gas, the ice making member 3,
The temperature of 3 is raised, and the close contact between the ice block 2 and the ice making surface 3A is released. As a result, the ice blocks 2 separated from the recesses 4 fall into the ice storage (not shown) located below.

In the ice-freezing process using the hot gas, the temperature ET of the refrigerant outlet side of the cooling pipe 6 detected by the outlet temperature sensor 26 is determined by the control unit 25 after the completion of the ice-making process. It ends when the temperature rises to, and then the ice making operation is started again. Here, it is empirically known that the deicing completion detection temperature KT that is sufficient for ending the ice block fall changes depending on the outside air temperature AT and the temperature WT of the deicing water supplied from the water supply solenoid valve 21. That is, when the outside air temperature AT is high and the ice removing water temperature WT is low, it is difficult for the ice blocks to fall, and it is necessary to raise the ice removal completion detection temperature. The outside air temperature AT is low and the ice removing water temperature WT is high. Even if the ice release completion detection temperature is lowered, the ice block can finish falling.

That is, considering these in terms of the relationship between AT, WT and ice-free completion detection temperature KT, "if AT is high and WT is low, it is necessary to increase KT" and "AT is low, W
It can be understood that the relationship is such that if T is high, KT is low. In determining the deicing completion detection temperature KT, the control unit 25 detects the outside air temperature AT and the deicing water temperature WT from the outputs of the outside air temperature sensor 28 and the water temperature sensor 29, and uses the above empirical rule. Then, the deicing completion detection temperature KT is determined experimentally using fuzzy inference according to a predetermined rule. The fuzzy control executed by the controller 25 will be described below.

As the input used for fuzzy inference, that is, the variable of the conditional part of the rule (fuzzy variable), the AT is the first.
, And the WT as a second input variable. The output, that is, the output variable of the conclusion part of the rule is KT
Take PB (quite expensive) as a fuzzy label,
Five are used: PS (slightly high), ZO (normal), NS (slightly low) and NB (quite low). 4 to 6 show the membership functions given to the fuzzy labels of the input variables AT and WT and the output variable KT as continuous functions. That is, the fuzzy labels of the input variables AT and WT are defined on the standardized set of 0 ° C to + 40 ° C, and the fuzzy labels of the output variables KT are defined on the standardized set of 0 ° C to + 20 ° C. . By quantifying such an ambiguous amount that is "quite", fuzzy inference can be performed.

Further, as a rule used for fuzzy inference, a combination of 13 rules shown in Table 1 can be considered based on an empirical rule in controlling this type of ice making machine. Table 1 shows the combinations of the input variables AT in the matrix and the labels in the input variable WT in the horizontal direction.
The label of the output variable KT as the conclusion part is shown at the intersection of the matrix. According to these rules, the ice making machine 1 is actually operated under various conditions of the outside air temperature AT and the water temperature WT by experiment, and the labels of the variables AT, WT, and KT are combined so that the deicing is always performed reliably. It is composed.

[0023]

[Table 1]

Each rule in Table 1 will be described in detail. First, the rule "If input variable AT = NBand input variable WT =
"NBthenKT = ZO" indicates the degree of satisfaction of the condition "when the outside air temperature AT is considerably low and the ice-breaking water temperature WT is also quite low, the ice-breaking completion detection temperature KT is made normal". Rule “If input variable AT = ZO and input variable W
“T = NBthenKT = PS” indicates the degree of satisfaction of the condition that “when the outside air temperature AT is normal and the ice-breaking water temperature WT is considerably low, the ice-breaking completion detection temperature KT is slightly increased”.

The rule "If input variable AT = PBand input variable WT = NBthenKT = PB" is that "when the outside air temperature AT is considerably high and the ice-cooling water temperature WT is considerably low, the de-icing completion detection temperature KT is set. The degree of satisfaction of the condition "to make it considerably high" is shown. Rule “If input variable AT = NSa
The “nd input variable WT = NSthenKT = ZO” indicates the degree of satisfaction of the condition that “when the outside air temperature AT is a little low and the ice-breaking water temperature WT is a little low, the ice-breaking completion detection temperature KT is normal”. .

The rule "If input variable AT = PSand input variable WT = NSthenKT = PS" is "when the outside air temperature AT is a little high and the ice water temperature WT is a little low,
The degree of satisfaction of the condition of "raising the ice removal completion detection temperature KT slightly" is shown. The rule “If input variable AT = NBand input variable WT = ZOthenKT = NS” states that “when the outside air temperature AT is considerably low and the ice icing water temperature WT is normal,
The degree of satisfaction of the condition of "lowering the ice-free completion detection temperature KT" is shown.

The rule "If input variable AT = ZOand input variable WT = ZOthenKT = ZO" is "when the outside air temperature AT is normal and the ice water temperature WT is also normal, the ice removal completion detection temperature KT is set. The degree of satisfaction of the condition of "normalize" is shown. Rule “If input variable AT = PBand input variable WT = ZOthenKT = PS” indicates that “outside air temperature AT is considerably high and deicing completion detection temperature KT is slightly increased when deicing water temperature WT is normal. The degree of satisfaction of the condition "" is shown.

The rule "If input variable AT = NSand input variable WT = PShenKT = NS" is that "when the outside air temperature AT is a little low and the ice water temperature WT is a little high,
The degree of satisfaction of the condition of "lowering the ice-free completion detection temperature KT" is shown. The rule “If input variable AT = PSand input variable WT = PSthenKT = ZO” is “when the outside air temperature AT is a little high and the ice-free water temperature WT is a little high,
The degree of satisfaction of the condition "normalize the ice-free completion detection temperature KT" is shown.

The rule "If input variable AT = NBand input variable WT = PBthenKT = NB" is that "when the outside air temperature AT is considerably low and the ice water WT temperature is considerably high, the ice removal completion detection temperature KT is set. The degree of satisfaction of the condition of "much lower" is shown. Rule “If input variable AT = ZOa
The nd input variable WT = PBthenKT = NS ”indicates the degree of satisfaction of the condition that“ when the outside air temperature AT is normal and the deicing water temperature WT is considerably high, the deicing completion detection temperature KT is lowered a little ”. .

The rule "If input variable AT = PBand input variable WT = PBthenKT = ZO" indicates that "when the outside air temperature AT is considerably high and the ice water temperature WT is also quite high, the ice removal completion detection temperature KT is set. The degree of satisfaction of the condition of "normalize" is shown. In the actual fuzzy inference, these fuzzy rules are used all or selectively and the outside air temperature sensor 28 and the water temperature sensor 29 are used to detect the temperatures AT and W.
The membership value according to the input variable AT and the membership value according to the input variable WT are obtained by measuring T and substituting them into each rule, and the minimum value of both membership values, that is, the smaller one Select the membership value as the success of the rule. In the conclusion part, the area of KT's membership function (set of units) below this degree of success is found for each rule, and the obtained total area is fuzzy combined by weighted average, and the center of gravity is found to infer the result. Output variable KT is determined.

Next, referring to FIG. 7, the above operation is executed assuming an actual situation. As an example, rule 1 "If
Input variable AT = PSand Input variable WT = NSthen
KT = PS ”and rule 2“ If input variable AT = ZOa
nd input variable WT = NBthenKT = PS ”,
Assuming that the outside air temperature AT obtained by the outside air temperature sensor 28 is + 23 ° C. and the temperature WT of the deicing water obtained by the water temperature sensor 29 is + 6 ° C., AT in FIG.
The input value of is +23, and the input value of WT is +6. In this case, the AT of Rule 1 has a membership value of 0.3 and WT
Then hit with a membership value of 0.6, A of rule 2
With a membership value of 0.7 for T, a membership value of 0.4 for WT.

The smaller one of the membership values obtained by each rule is selected as the degree of success, and in Rule 1, the area below 0.3 of the membership function of KT in the conclusion part is obtained, and in Rule 2, the conclusion is obtained. When the area below 0.4 of the KT membership function of the section is obtained and the areas are overlapped as indicated by the arrows in the figure and the center of gravity thereof is obtained, + 15 ° C is obtained. This determines KT = + 15 ° C. That is,
When the outside air temperature AT is + 23 ° C and the deicing water temperature WT is + 6 ° C, the deicing completion detection temperature KT is + 15 ° C.

Here, the outside air temperature AT is considerably low (N
B), when the temperature WT of the deicing water is considerably high (PB),
As is clear from Table 1, since the ice removal completion detection temperature KT is controlled to a direction (NB) that is considerably lowered, an unnecessarily long and useless time from the end of the ice block drop to the end of the hot gas as in the conventional case. It can also be taken away. That is, A
Since the height of KT is adjusted according to the fluctuations of T and WT, it becomes possible to determine an appropriate ice-free completion detection temperature according to the situation.

In the fuzzy control described above, in the embodiment, the outside air temperature and the deicing water temperature are directly detected from the refrigerant outlet side temperature of the condenser 9 and the temperature of the sprinkler 20, but the present invention is not limited to this. The transition of the temperature on the refrigerant outlet side of the pipe 6
Paying attention to the fact that it changes depending on the outside air temperature and the temperature of the ice-free water, the outside air temperature and the temperature of the ice-free water may be indirectly detected from the transition time of the output from the outlet temperature sensor 26. According to this, one sensor can be used.
In addition, in the embodiment, the inference is performed using two rules, but it goes without saying that if inference is performed using all or more rules, an accurate inference result can be obtained according to any situation. .

[0035]

As described above, according to the present invention, the defrosting completion detection temperature is determined by fuzzy inference using a value that changes depending on the outside air temperature and the temperature of the supplied deicing water as an input variable. It is possible to set an accurate deicing completion detection temperature for fluctuations in the temperature of ice water, thereby improving the ice making capacity without wasting defrosting time and achieving reliable deicing. Will be able to.

In particular, since the control is performed based on the experimentally determined rule, only the qualitative relationship needs to be determined, and there is an advantage that the mathematical model is unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device.

FIG. 2 is a system configuration diagram of an ice making machine.

FIG. 3 is a perspective view of an essential part of the ice making machine.

FIG. 4 is a diagram showing a membership function of an input variable AT.

FIG. 5 is a diagram showing a membership function of an input variable WT.

FIG. 6 is a diagram showing a membership function of an output variable KT.

FIG. 7 is a diagram illustrating a fuzzy inference method.

FIG. 8 is a diagram showing a time transition of a temperature ET in the case of low outside air temperature.

FIG. 9 is a diagram showing a time transition of a temperature ET in the case of a medium outside temperature.

FIG. 10 is a diagram showing a time transition of a temperature ET in the case of a high outside air temperature.

[Explanation of symbols]

1 ice machine 3 ice making members 6 cooling pipes 7 Electric compressor 9 condenser 11 Bypass pipe 12 Hot gas solenoid valve 13 Water sprinkler for ice making 17 Circulation pump 20 Water sprinkler for ice removal 25 Control unit 26 Outlet temperature sensor 28 Outside temperature sensor 29 Water temperature sensor

Claims (2)

[Claims] 1. An ice making means provided with a cooler, an ice removing means, a water supply means for supplying water for ice removing, an ice making step for forming ice blocks by the ice making means, and an ice making block from the ice making means by the ice removing means. The ice removing process for releasing the ice is alternately repeated, and during the ice removing process, water for ice removing is supplied to the ice making means by the water supply means, and the temperature of the cooler reaches a predetermined ice removal completion detection temperature. And a control means for terminating the deicing process when the temperature reaches the defrosting completion temperature. When determining the deicing completion detection temperature in the control means, a value that changes based on the outside air temperature and a value that changes based on the temperature of the deicing water are input. An ice machine characterized by using fuzzy inference as variables. 2. A member corresponding to both input variables of a plurality of inference rules, wherein the outside air temperature is used as a first input variable and the ice-free water temperature is used as a second input variable. -Fuzzy inference characterized in that after the ship value is obtained, the output variables of the inference rule are fuzzy combined and the center of gravity thereof is taken to obtain an inference result, which is used to determine the ice-free completion detection temperature. Control method for ice machines.