JPH08338675A - Method and device for preventing imperfect ice generation in water circulation type ice making machine - Google Patents

Abstract

PURPOSE: To provided a method and device for preventing an imperfect ice generation in a water circulation type ice making machine which is designed to take measure against the generation of imperfect ice, only when it is required for the prevention of generation of flaked ice. CONSTITUTION: A water circulation type ice making machine supplied circulatingly water to manufacture ice to an ice making board 15 by driving a circulation pump 3 in an ice making water circuit during an ice making cycle, and supplies circulatingly refrigerants to a vaporizer which is in a heat- exchange relation with the ice making board 15 in a freezing circuit by way of a refrigerant solenoid valve 18 by driving a compressor 11, thereby to make ice. To prevent the generation of imperfect ice in the water circulation type ice making machine, time from the starting time point of the ice making cycle is measured by a timer 21 under control of a control device 20, and the temperature of the manufactured ice supplied circulatingly is detected with a temperature detector 8. In the case when the time required to cool the manufactured ice to a specified temperature exceeds a specified time, the circulation pump 3 is suspended or the refrigerant solenoid valve 18 is closed temporarily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention circulates an ice making water to an ice making plate by a circulation pump during an ice making cycle, and a compressor is used to supply a refrigerant to an evaporator in a heat exchange relationship with the ice making plate. The present invention relates to a water circulation type ice making machine that circulates and supplies ice through a valve, and particularly to a cotton-like or mud-like incomplete ice (hereinafter referred to as cotton ice or incomplete ice) that is peculiar to the water circulation type ice making machine. The present invention relates to a method and a device for preventing the phenomenon of (call) from occurring.

[0002]

2. Description of the Related Art What is a water circulation type ice maker?
It is an ice-making machine of the type that makes ice-making water flow on the surface of an ice-making plate or an ice-making chamber and repeats it to generate almost pure ice on which the impurities contained are substantially removed. Various types are known depending on the model, but all have a freezing point of 0 ° C to freeze running water.
The feature is that it is lower, and it is common that incomplete ice is generated in the circulation path of ice making water just before freezing starts. Various methods have been conventionally known as methods for preventing the generation of such incomplete ice, for example, Japanese Patent Publication No. 58-157.
As described in Japanese Patent Laid-Open No. 06-06, when the temperature of ice making water for predicting the occurrence of incomplete ice reaches a certain set value, the ice making water circulation pump connected to the ice making water tank is temporarily stopped. Thus, there is a technique in which a portion of the water circulation path where incomplete ice is likely to occur is put into a supercooled state and the water in that portion is frozen at a stretch, and after the operation of the ice making water circulation pump is restarted, the freezing portion is used as a core to advance the freezing.

Japanese Patent Publication No. 6-21753 discloses that
When the temperature of ice-making water that predicts the occurrence of incomplete ice reaches a certain set value, the refrigerant solenoid valve or expansion valve is temporarily closed to rapidly cool the evaporator. A technique for promoting freezing as a nucleus is disclosed.

[0004]

However, any method based on the temperature of ice-making water can prevent the generation of cotton ice itself, but by taking measures for it, incidental problems will occur. In that respect, there are merits and demerits, and at present there is no one that can solve even an incidental problem. For example, in the former method of stopping the ice-making water circulation pump, the refrigeration load applied to the compressor is substantially lost when the pump is stopped, so that the refrigerant returns to the compressor in a liquid phase state, which causes the failure of the compressor. I found out. Further, when the former technique is applied to an ice making machine of a type having a deicing water tank, when the ice making water circulation pump is stopped, the ice making water cooled in the water circulation passage overflows when it returns to the ice making water tank. Since it flows down to the deicing water tank, not only is the energy wasted to drain the cooled deicing water, but the deicing water temperature in the deicing water tank decreases, which increases the deicing time and reduces the ice making capacity. It turns out that there is a problem.

Further, in the latter type in which the solenoid valve for refrigerant or the expansion valve is closed, the ice making water circulation pump is not temporarily stopped, so the above-mentioned disadvantages of the former type can be solved.
When the solenoid valve for expansion or the expansion valve is closed when the outside air temperature is low, the low-pressure pressure of the refrigeration circuit drops, so the low-pressure switch may operate, shut down the compressor, and shut down the ice maker. was there. Moreover, with regard to cotton ice, there are many points in which the mechanism of its occurrence has not been clarified yet, but according to the knowledge or experience of the present inventor, for example,
It has been found that this often occurs when the frequency of the power supply is 50 Hz and when the outside air temperature is high.
That is, it was empirically known that incomplete ice formation does not occur when the outside air temperature is low, but nevertheless, both of the former one and the latter one, for example, even when the outside air temperature is low,
When the temperature of the ice-making water that predicts the generation of incomplete ice reaches a certain set value, countermeasures for preventing the generation of cotton ice are taken, and the above-mentioned incidental problem is purposely caused. Therefore, the present invention mainly provides a method and a device for preventing generation of incomplete ice in a water circulation type ice making machine, which takes measures only when it is necessary to take measures to prevent the generation of cotton ice. It is intended.

[0006]

In order to achieve the above object, according to the present invention, in the ice making water circuit during the ice making cycle, the ice making water is circulated and supplied to the ice making plate by the circulation pump, and the refrigerating circuit is also provided. In order to prevent the generation of incomplete ice in a water circulation type ice maker that makes ice by making a refrigerant circulate and supply a refrigerant by a compressor through a refrigerant solenoid valve to an evaporator that is in a heat exchange relationship with the ice making plate. , Measuring the time from the start of the ice making cycle, detecting the temperature of the ice making water being circulated and supplied, when the time until the ice making water is cooled to a predetermined temperature exceeds a predetermined time, There is provided a method for preventing generation of incomplete ice in a water circulation type ice making machine, which temporarily stops the circulation pump or closes the refrigerant electromagnetic valve. According to the knowledge of the present inventor, the time until the ice-making water is cooled to a predetermined temperature becomes longer under the condition that incomplete ice is likely to be generated. Therefore, if this time is shorter than the predetermined time, it may be considered that incomplete ice does not occur, and therefore, the present invention does not take measures to prevent cotton ice. However, if the above time exceeds a predetermined time, the occurrence of cotton ice is predicted, so countermeasures against cotton ice, that is, the circulation pump is stopped or the refrigerant solenoid valve is closed, are temporarily performed.

The time for stopping the circulation pump or closing the solenoid valve for the refrigerant, that is, the cotton ice countermeasure time, is selected in proportion to the length of time until the ice making water is cooled to the predetermined temperature. It is preferable. The long time from the start of the ice making cycle to the execution of the cotton ice countermeasure indicates that the refrigeration capacity has decreased or decreased. If the cotton ice countermeasure time is kept constant, the ice freezing temperature and the evaporator The cotton ice countermeasure may be insufficient because the difference from the temperature cannot be made large. However, by varying the cotton ice countermeasure time as described above, the prevention of the cotton ice is more surely prevented.

According to another aspect of the present invention, in a water circulation type ice making machine, a compressor circulates and supplies a refrigerant through a refrigerant electromagnetic valve and an expansion valve to make ice, and the ice making water reaches a predetermined temperature. If the time until cooling exceeds the specified time,
Temporarily close the expansion valve as a measure to prevent cotton ice. According to still another aspect of the present invention, since the low pressure of the refrigerant substantially corresponds to the temperature of the ice making water, instead of detecting the temperature of the ice making water, a pressure switch is attached to the low pressure part of the refrigeration circuit,
The pressure switch detects when the low pressure of the refrigerant in the refrigeration circuit reaches a predetermined value, and when the time exceeds a predetermined time, the solenoid valve for expansion or the expansion valve is temporarily closed. There is. Furthermore, according to the present invention, since the temperature of the evaporator substantially corresponds to the temperature of the ice making water, a temperature detector for detecting the saturation temperature of the refrigerant is attached to the inlet side of the evaporator, and the temperature detector evaporates. The time when the temperature of the container reaches a predetermined value is detected, and when the time exceeds a predetermined time, the electromagnetic valve for the refrigerant or the expansion valve is temporarily closed.

One end of the refrigeration pipe is led out from the refrigeration circuit at the inlet side of the refrigerant solenoid valve, the other end is connected to the outlet side of the expansion valve, and an auxiliary solenoid valve is provided in the refrigeration pipe to provide the refrigerant solenoid valve. Alternatively, if the auxiliary electromagnetic valve is opened when the expansion valve is closed, the low-pressure pressure of the refrigerant does not drop to the extent that it causes the compressor to stop when the refrigerant electromagnetic valve is closed, which is preferable. In addition, in this case, the length of time from the closing of the solenoid valve for expansion of the refrigerant or the expansion valve to the reopening of the valve and the length of time from the opening of the auxiliary solenoid valve to the closing of the auxiliary solenoid valve Controlling with the prevention timer is advantageous because the formation of ice nuclei can be surely promoted on the ice making plate during this period. According to the present invention, preferably, the refrigeration circuit is provided with a low-pressure pressure switch, and even when the working pressure of the low-pressure pressure switch is reached when the refrigerant solenoid valve or expansion valve is closed, Disable operation. This deactivates the low pressure switch, thus preventing undesired shutdown of the compressor. Further, according to another aspect of the present invention, during the ice making cycle, in the ice making water circuit, the ice making water is circulated and supplied to the ice making plate by the circulation pump, and in the refrigerating circuit, the evaporation which has a heat exchange relationship with the ice making plate is performed. In order to prevent the generation of incomplete ice in a water circulation type ice maker which circulates and supplies a refrigerant to a container through a solenoid valve for refrigerant, a time is counted from the start point of the ice making cycle. When a time measuring means, a detecting means for detecting the temperature of the ice-making water being circulated and supplied, and the time until the ice-making water is cooled to a predetermined temperature exceeds a predetermined time, the circulation pump is stopped or the There is provided a device for preventing generation of incomplete ice in a water circulation type ice making machine, which is provided with a control device that temporarily closes a solenoid valve for a refrigerant.

[0010]

Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. FIG. 1 is a schematic view showing an example of a water circulation type ice making machine in which the present invention is implemented. This ice making machine is of a type similar to the ice making machine disclosed in Japanese Patent Publication No. 58-15706, and includes an ice making water tank 1, a deicing water tank 2, and ice making water connected to the ice making water tank 1. Circulation pump 3, a deicing water circulation pump 4 connected to the deicing water tank 2, a sprinkler 5 connected to the circulation pump 3 and supplied with ice-making water, and a deicing water supply connected to the circulation pump 4. It includes a water circuit consisting of a water sprinkler 6 for receiving, an ice making plate 15 and the like. In the embodiment, the ice making plate 15 is, for example, a vertical type ice making plate vertically installed as described in Japanese Patent Publication No. 58-15706, and its back surface is
Although not shown, an evaporator forming a part of a refrigeration circuit to be described later is arranged in a meandering shape in a heat exchange relationship. A fountain-type ice making chamber may be used, and in this specification, such an ice making chamber is also referred to as an ice making plate. This ice plate 15
Further, during the ice making cycle, the ice making water is circulated and sprinkled by the circulation pump 3, and during the deicing cycle, the deicing water is sprinkled by the circulation pump 4. Also,
In the closed refrigeration circuit of the ice machine, in addition to the evaporator described above,
A compressor 11, a condenser 12, a refrigerant solenoid valve 18, a heat exchanger 13, an expansion valve 14, an accumulator 16 and a hot gas solenoid valve 17 are provided. The hot gas solenoid valve 17 is provided in a hot gas pipe 17a that directly connects the outlet of the compressor 11 and the inlet of the evaporator by bypassing the condenser 12 and the like.

The deicing cycle is started when the water level in the ice making water tank 1 is lowered to a certain level. When the circulation pump 4 is activated, the deicing water enters the water sprinkler 6 from the deicing water tank 2 through the pipe, and the ice making plate 15 passes through the water sprinkling hole.
Is sprayed on the back surface of the water and flows down, and enters the ice-making water tank 1 through a path such as the water collecting gutter 15a. At the same time, the hot gas pipe 17
The hot gas solenoid valve 17a is opened, and hot gas is supplied to an evaporator (not shown) to remove the ice adhering to the surface of the ice making plate. Then, the ice making water tank 1 is filled with deicing water.

Next, the ice making cycle is started after a lapse of a predetermined time from the start of the deicing cycle or when the intake gas temperature is detected and the set condition is satisfied. The circulation pump 3 was started, and the ice making water entered the water sprinkler 5 from the ice making water tank 1 through the pipe line, was sprayed from the water sprinkling hole to the surface of the ice making plate 15, and flowed down, so that the ice making plate did not become ice. About the amount, it enters into the ice making water tank 1 and circulates through a path such as a water collecting gutter 15a. At the same time, in the refrigeration circuit, the hot gas solenoid valve 17 is closed and the refrigerant solenoid valve 18 is opened, so that the refrigerant flows from the compressor 11 to the condenser 12, the heat exchanger 13,
After entering the evaporator through the expansion valve 14 and cooling the ice making plate 15, the heat exchanger 13, the accumulator 16 and the compressor 11 are cooled.
And circulate. By repeating the deicing cycle and the ice making cycle in this manner, ice is generated and stored in an ice storage (not shown).

As mentioned at the beginning, in the water circulation type ice making machine, ice crystals (incomplete ice or cotton ice, mud ice) are instantaneously generated from the supercooled water, and the pipes, the water collecting trough, and May obstruct the flow of ice-making water in the ice-making plate. Therefore, in Japanese Patent Publication No. 58-15706, as shown in FIG. 1 and, as can be seen from the time chart of FIG. 2, the ice-making water temperature is detected at a portion where the ice-making machine is located, for example, near the water collecting gutter 15a. A temperature detector 8 such as a thermostat is provided to predict the occurrence of incomplete ice, for example, time t1 when the temperature gradually decreases and reaches between + 1 ° C and 0 ° C.
Is detected, and the circulation amount of water in the circulation path is reduced to a predetermined value or less by a predetermined time (cotton ice countermeasure time) t2 by this detection signal. Specifically, the operation of the circulation pump 3 is temporarily stopped to prevent the generation of incomplete ice. As a result, the surface of the ice making plate is supercooled or the formation of the initial ice film is forced, and even if the supply of the ice making water is restarted after the predetermined time t2, cotton ice is no longer generated. Therefore, the predetermined time t2 means that the surface of the ice making plate is supercooled by interruption of the ice making water or an initial ice film is formed by reducing the load of the ice making water. It is the minimum time required to cool to the extent that cotton ice is not generated even when it is supplied.

Further, as described in Japanese Patent Publication No. 58-15706, the timing of cotton ice formation varies depending on various conditions. For example, cotton ice is easily generated under the following conditions. I understand. (1) When the material of the ice making plate is aluminum, it occurs more frequently than when it is made of copper. (2) The efficiency of the evaporator (ice plate) and the compression function force are not well balanced, and the compression function force is often lower than that. (3) When the amount of circulating water is too large, or when the flow velocity is low. (4) When the temperature and water temperature are high, such as in summer. (5) The occurrence tendency is stronger in the 50 Hz area than in the 60 Hz area (the rotational speeds of the compressor and the circulation pump influence). (6) The first ice-making cycle after a long shutdown. (7) Insufficient amount of cooling water for the condenser or insufficient amount of air for the air-cooled condenser. (8) In the vertical flat plate type ice making mechanism that circulates both ice making water and de-icing water as a circulation, when the ice making water becomes high in temperature immediately after de-icing due to an operation error. The invention of Japanese Examined Patent Publication No. 58-15706 teaches that the predetermined time t2 is appropriately determined in consideration of the above-mentioned conditions, and that the timing of occurrence of cotton ice (t1) varies depending on the above-mentioned conditions. There is.

On the other hand, FIG. 3 is a schematic view showing another example of a water circulation type ice making machine in which the present invention is implemented, and FIG. 4 is a time chart corresponding to FIG. In this ice making machine as disclosed in Japanese Examined Patent Publication No. 6-21753, the pressure switch 19 is attached to the low-pressure part (accumulator 16) of the refrigeration circuit in the one described in Japanese Patent Publication No. 58-15706. At the same time, a temperature detector 22 that can detect the saturation temperature of the refrigerant is additionally provided on the inlet side of the evaporator. The pressure switch 19 or the temperature detector 22 predicts the occurrence of incomplete ice at a site where the ice machine is made. A change, that is, a time point (t1) when the low pressure of the refrigeration circuit or the refrigerant temperature of the evaporator reaches a predetermined value is detected, and in response to this detection signal,
The refrigerant solenoid valve 18 (which may be the expansion valve 14) is temporarily closed for a predetermined time (t2). By closing the electromagnetic valve 18 or the expansion valve 14 as described above, the evaporator rapidly cools and the temperature lowers, and ice nuclei necessary for normal ice growth are formed on the surface of the ice making plate 15. Therefore, it is possible to prevent the generation of cotton ice particularly on the ice making plate 15.

Also in the invention of Japanese Patent Publication No. 6-21753, the above predetermined time t2 for closing the electromagnetic valve for refrigerant or the expansion valve is appropriately determined in consideration of the above-mentioned various conditions. The low-pressure pressure of the refrigeration circuit is in direct proportion to the temperature of the evaporator, and the constant pressure value can be easily converted from the constant temperature value.

According to the knowledge of the inventor of the present invention, all of the above conditions (1) to (8) in which cotton ice is likely to occur are the time from the start of the ice-making cycle to the start of execution of the cotton-ice countermeasure, that is, the ice-making cycle. Is a factor that prolongs the time from the start of the ice to the change that predicts the occurrence of incomplete ice in some part of the ice machine. From this fact, the present inventor attaches a timer to the water circulation type ice making machine as described in Japanese Patent Publication No. 58-15706 and Japanese Patent Publication No. 6-21753, and after the ice making cycle is started, the timer is set to a predetermined value. It is proposed that if the time is increased before the time comes, then no countermeasures against cotton ice will be taken even if the ice-making water reaches a condition where cotton ice is likely to be generated thereafter.

That is, referring to FIG. 1, the water circulation type ice maker according to the present invention includes an electronic control unit 20 which, in this embodiment, may be a microcomputer, which is not shown in the figure. The output interface is connected to the compressor 11, the circulation pump 3, the timer 21 (time measuring means), the above-mentioned temperature detector 8 (detection means) for directly or indirectly detecting the temperature of the circulating ice-making water, the delay relay 23 and the like. As a result, various input / output signals are transmitted / received, and the memory (not shown) stores a preset cotton ice countermeasure execution start time. The temperature detector 8 is not limited to the installation site shown in the figure, but can be installed at an appropriate site where ice-making water circulates. When the temperature detector 8 detects a predetermined temperature of ice-making water (a temperature at which a thin ice film that forms the basis of incomplete ice is likely to be formed) and the detection signal is input to the control device 20, The control device 20 stops the circulation pump 3 and operates the delay relay 23 to restart the circulation pump 3 after the above-described predetermined time.

On the other hand, the time required for the ice-making water to reach the predetermined temperature at which cotton ice is likely to occur varies depending on the above-mentioned conditions, and generally becomes longer when cotton ice is likely to occur.
It shortens when it is difficult to occur. Then, if cotton ice generation prevention measures are taken despite the difficulty of generating cotton ice, as described at the beginning, the refrigeration load applied to the compressor 11 is substantially eliminated, so that the refrigerant is in a liquid phase state. Returning to the compressor, this causes the compressor 11 to malfunction. Therefore, according to the present invention, the above-mentioned timer 21 that is turned on at the same time as the start of the ice making cycle is additionally provided, and the time counting signal from this timer 21 is sent to the control device 20. The time until the timer 21 times out is set shorter than the time until the ice-making water reaches the predetermined temperature when cotton ice is likely to be generated. Therefore, under the condition that cotton ice is unlikely to occur, when the timer 21 times up and sends the signal to the control device 20 before the ice making water reaches the predetermined temperature, the control device 20 causes the temperature detector to detect the temperature. 8, delay relay 23,
The cotton ice countermeasure circuit including the circulation pump 3 etc. is disabled to prohibit the cotton ice generation prevention measures.
The disadvantages of the one described in JP-A-06 are avoided.

In this embodiment, the temperature of the ice making water is detected by the temperature detector 8 in order to detect the occurrence of cotton ice. However, a temperature detecting device such as a thermostat installed on the low pressure side of the refrigerating circuit is used. When the temperature of the refrigerant is detected by the container, the control can be performed in substantially the same manner as described above. Further, as described above, since the low pressure of the refrigeration circuit is in direct proportion to the temperature of the evaporator, the low pressure of the refrigeration circuit is detected by the pressure switch. If it is up, you may not want to take measures to prevent cotton ice.

In the water circulation type ice maker shown in FIG. 3, a pressure switch 19 is provided in the low pressure section (accumulator 16) of the refrigeration circuit.
When the present invention is applied to the one in which the temperature detector 22 capable of detecting the saturation temperature of the refrigerant is additionally provided on the inlet side of the evaporator, the cotton ice is preferably used in a manner substantially similar to that described above. Occurrence is prevented. In that case, the control target is almost the same except that the circulation pump 3 is changed to the refrigerant solenoid valve 18 or the expansion valve 14, and thus detailed description will be omitted. After that, the timer 21 times up, and then, when the ice making water temperature is cooled to a predetermined temperature, the temperature detector 8 operates to close the refrigerant solenoid valve 18, and after closing the solenoid valve 18,
When the temperature around the temperature detector 22 is cooled to a certain temperature,
The temperature detector 22 operates to open the electromagnetic valve 18 for the refrigerant, and the normal ice making cycle is resumed. That is, in this embodiment, the temperature detector 22 is operated from the time when the temperature detector 8 is activated.
The cotton ice countermeasure time t2 is up to the point of operation. Of course, if the temperature detector 8 operates before the timer 21 times out, the cotton ice countermeasure circuit is not activated and unnecessary countermeasures against cotton ice are not taken.

FIG. 5 shows the change over time in the ice making water temperature in the ice making cycle, and t1 represents the time from the start of the ice making cycle to the countermeasure against cotton ice. FIG. 6 shows the relationship between the outside air temperature (the same applies to water temperature) and the time t1 until the countermeasure against cotton ice for each power supply frequency, and FIG. 7 shows the time from the start of the ice making cycle until the countermeasure against cotton ice and the countermeasure against cotton ice t2. Shows the relationship. Further, as can be seen from FIG. 7, the time for stopping the circulation pump or closing the solenoid valve for refrigerant may be changed in proportion to the length of time until the ice-making water is cooled to a predetermined temperature. The fact that the time t1 from the start of the ice making cycle to the execution of the cotton ice countermeasure is long indicates that the refrigerating capacity has decreased, and if the cotton ice countermeasure time t2 is kept constant, the ice freezing temperature and the evaporator The cotton ice countermeasure may be insufficient because the difference from the temperature cannot be made large, but the cotton ice countermeasure time t2 is variable as described above, so that the cotton ice generation is more reliably prevented. .

The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and various modifications can be made. For example, the timer 21 and the delay relay 23 may have a timer function built in the control device 20, or the control device 20 may be an electric operation control circuit of the ice making machine instead of the microcomputer.

Furthermore, in the embodiment of FIG. 3, as described above, the cotton ice countermeasure time t2 is from the operating time point of the temperature detector 8 to the operating time point of the temperature detector 22, and, of course, during this period. Since the compressor 11 is operating, the cotton ice countermeasure time t2 must be limited to a relatively short time (see (a) of FIG. 9). Therefore, it is preferable to extend the cotton ice countermeasure time t2 so as to more reliably form ice nuclei on the ice making plate. Therefore, in the modified embodiment shown in FIG. 8, the refrigerating pipe 2 is inserted from the inlet side of the refrigerant solenoid valve 18.
One end of No. 4 is led out and the other end is connected to the outlet side of the expansion valve 14, and an auxiliary electromagnetic valve 25 and an auxiliary constant pressure expansion valve 26 are provided in series in the refrigeration pipe 24. The expansion valve 26 is preferably a pulse motor type, and when the ice making water reaches a predetermined temperature during the ice making cycle, its opening can be slightly narrowed to be smaller than that of the expansion valve 14 to suppress the passage of the refrigerant. .

In FIG. 8, after the ice making cycle is started and before the timer 21 times out, the ice making water is cooled to a predetermined temperature and the temperature detector 8 operates.
The refrigerant solenoid valve 18 is closed, but conversely the auxiliary solenoid valve 25
Is designed to be opened. Then, after a certain period of time that can be adjusted by the cotton ice prevention timer 27, the refrigerant solenoid valve 18 opens and the auxiliary solenoid valve 25 closes to return to the normal ice making cycle. The time during which the refrigerant solenoid valve 18 is closed and the auxiliary solenoid valve 25 is opened is the cotton ice countermeasure time t2. Since the refrigeration circuit is provided with the low pressure switch 19, unless the refrigeration pipe 24 having the solenoid valves 25 and 26 is provided, when the refrigerant solenoid valve 18 is closed, the refrigeration circuit on the downstream side thereof is closed. The refrigerant is the compressor 11
The low pressure switch 19 is activated and the compressor 11 is stopped. However, the auxiliary solenoid valve 25 and the auxiliary constant pressure expansion valve 26 are provided in the refrigerating pipe 24 to close the solenoid valve 18 as described above. Since the auxiliary solenoid valve 25 is sometimes opened, the operation of the low pressure switch 19 can be blocked. Therefore, as shown in FIG. 9B, the low evaporation temperature can be maintained for a long time, and the cotton ice prevention timer 27 can set the cotton ice countermeasure time t2 to be long to surely form ice nuclei. You can

The constant pressure expansion valve 26 is preferable because it does not operate the low pressure switch 19 even when the outside air temperature is low in order to prevent the low pressure from falling below the set value. Further, even if a capillary tube is used instead of the constant pressure expansion valve 26 in order to make the refrigeration circuit inexpensive, it is possible to prevent the generation of cotton ice when the outside temperature is high, and the low pressure switch 19 can be used even when the temperature becomes low. Does not work.

Further, in the water circulation type ice maker shown in FIG. 3, the temperature detector 22 is not provided, but an operation avoidance circuit (not shown) for the low pressure switch 19 is provided instead of the temperature detector 22 to ensure the generation of cotton ice. Can be prevented. In the case of this modified example, description will be given with reference to FIG. 3, as shown in the low pressure curve of FIG. 10 and the time chart of FIG.
After the start of the ice making cycle and before the timer 21 times out, the ice making water is cooled to a certain temperature, and the temperature detector 8
At the same time that the temperature is detected, the refrigerant solenoid valve 18 is closed, a timer such as the cotton ice prevention timer 27 of FIG. 8 is turned on, and even if the operating pressure of the low pressure switch 19 is reached, the low pressure switch 19 is reached. An activation avoidance circuit (not shown) that disables the activation of 19 is activated. Therefore, the time until the above-mentioned cotton ice prevention timer times out is the cotton ice countermeasure time t
It becomes 2. When the cotton ice prevention timer 27 is turned off by the prevention of cotton ice, the refrigerant solenoid valve 18 is opened, and the low pressure pressure switch avoidance release timer (not shown) is activated for a while (time t3), The low pressure switch 19 recovers and returns to the normal ice making cycle.

According to this modified embodiment, it is possible to secure a sufficient cotton ice countermeasure time t2 without operating the low pressure switch, so that the low pressure (evaporation temperature) that is lower and longer than the conventional one can be maintained and ensured. It can prevent the generation of cotton ice. Further, the cotton ice countermeasure time t2 is several tens of seconds, but as the time elapses, the low pressure decreases and the high compression ratio operation is performed. The high compression ratio operation state is not so long, but if the temperature of the discharge pipe of the compressor rises, it is possible to protect it by providing a temperature detector in the discharge pipe.

[0029]

As will be understood from the above description, according to the present invention, the cotton ice formation preventing measure is taken only under the condition where the cotton ice formation is likely to occur. Therefore, the cotton ice formation preventing measure is taken. Although it is unnecessary, it is possible to prevent incidental drawbacks that are particularly noticeable by taking measures, such as a decrease in ice making function and a failure of the compressor due to liquid back to the compressor. it can. In this case, if the length of time for taking measures to prevent the production of cotton ice is set to be proportional to the time until the ice making water is cooled to a predetermined temperature after the start of the ice making cycle, it is more reliable. It can prevent the generation of cotton ice. In addition, if an auxiliary solenoid valve is provided in the refrigeration piping and the auxiliary solenoid valve is opened when the refrigerant solenoid valve or expansion valve is closed, even if the refrigerant solenoid valve is closed, the refrigeration circuit The low pressure does not drop so much and does not shut down the compressor. Further, the length of time from when the refrigerant solenoid valve or expansion valve is closed to when it is reopened and when the auxiliary solenoid valve is opened to when it is closed again is defined by the cotton ice prevention timer. If it is controlled by the above method, not only can the cotton ice be prevented from being generated more reliably, but also the present invention can be applied to various water circulation type ice makers. If a low-pressure pressure switch operation avoidance circuit is attached and a cotton ice prevention timer is provided, the cotton ice prevention timer can change the cotton ice countermeasure time regardless of the operation of the pressure switch. It can also be used with a type ice machine.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a water circulation type ice making machine in which an embodiment of the present invention is incorporated.

FIG. 2 is a timing chart explaining the operation of various elements in the embodiment of FIG.

FIG. 3 is a schematic view showing a water circulation type ice making machine in which another embodiment of the present invention is incorporated.

FIG. 4 is a timing chart explaining the operation of various elements in the embodiment of FIG.

FIG. 5 is a graph showing a change in ice making water temperature in an ice making cycle.

FIG. 6 is a graph showing the relationship between the outside air temperature and the time from the start of the ice making cycle to the time when countermeasures against cotton ice are taken, for each two power supply frequencies.

FIG. 7 is a graph showing the relationship between the time from the start of the ice making cycle to the time to take measures against cotton ice, and the time to take measures against cotton ice.

FIG. 8 is a schematic view showing a water circulation type ice making machine in which still another embodiment of the present invention is incorporated.

9 (a) and 9 (b) are graphs for explaining the relationship between time and low pressure.

FIG. 10 is a graph corresponding to FIG. 9 according to another embodiment of the present invention.

11 is a timing chart corresponding to FIG. 1 for the embodiment of FIG.

[Explanation of symbols]

3 ... Circulation pump for ice making water, 8 ... Temperature detector (detection means) for ice making water, 11 ... Compressor, 12 ... Condenser, 14 ... Expansion valve, 15 ... Ice making plate, 18 ... Solenoid valve for refrigerant, 19 ... Low-pressure pressure switch, 20 ... Control device, 21 ... Timer (time measuring means), 22 ... Temperature detector, 23 ... Delay relay, 24 ... Refrigeration piping, 25 ... Auxiliary solenoid valve, 26 ... Constant pressure expansion valve, 27
… A cotton ice prevention timer.

Claims (9)

[Claims] 1. An ice making water circuit circulates and supplies ice making water to an ice making plate in an ice making water circuit during an ice making cycle, and in a refrigerating circuit, a compressor is provided to an evaporator in a heat exchange relationship with the ice making plate. In order to prevent the generation of incomplete ice in a water circulation type ice making machine that circulates and supplies a refrigerant through a solenoid valve for a refrigerant, the time from the start point of the ice making cycle is measured and circulated. The temperature of the ice making water is detected, and when the time until the ice making water is cooled to a predetermined temperature exceeds a predetermined time, the circulation pump is stopped or the refrigerant solenoid valve is closed temporarily. , Method of preventing the generation of incomplete ice in a water circulation type ice maker. 2. The time for stopping the circulation pump or closing the solenoid valve for refrigerant is selected in proportion to the length of time until the ice-making water is cooled to the predetermined temperature. 1. The method for preventing the generation of incomplete ice according to 1. 3. During the ice making cycle, in the ice making water circuit, the ice making water is circulated and supplied to the ice making plate by a circulation pump, and in the refrigerating circuit, an evaporator in a heat exchange relationship with the ice making plate is provided with a compressor. In order to prevent the generation of incomplete ice in a water circulation type ice making machine that circulates and supplies a refrigerant through a solenoid valve and an expansion valve for the refrigerant, the time from the start point of the ice making cycle is measured and circulated and supplied. A water circulation type ice maker that detects the temperature of the ice making water being stored and temporarily closes the expansion valve when the time until the ice making water is cooled to a predetermined temperature exceeds a predetermined time. To prevent the generation of incomplete ice in. 4. In the ice making cycle, in the ice making water circuit, the ice making water is circulated and supplied to the ice making plate by a circulation pump, and in the refrigerating circuit, the evaporator is placed in a heat exchange relationship with the ice making plate by a compressor. In order to prevent the generation of incomplete ice in a water circulation type ice making machine that circulates and supplies a refrigerant through an electromagnetic valve for refrigerant and an expansion valve, the time from the start of the ice making cycle is measured, and the freezing is performed. A pressure switch is attached to the low pressure part of the circuit, the time point when the low pressure of the refrigeration circuit reaches a predetermined value is detected by the pressure switch, and when the time point exceeds a predetermined time, the refrigerant solenoid valve or the expansion A method for preventing the generation of incomplete ice in a water circulation type ice maker that temporarily closes the valve. 5. During the ice making cycle, in the ice making water circuit, ice making water is circulated and supplied to the ice making plate by a circulation pump, and in the refrigerating circuit, the evaporator, which is in heat exchange relation with the ice making plate, is provided with a compressor. In order to prevent the generation of incomplete ice in the water circulation type ice making machine that makes ice by circulating and supplying the refrigerant through the electromagnetic valve for refrigerant and the expansion valve, the time from the start point of the ice making cycle is measured and the evaporation is performed. A temperature detector for detecting the saturation temperature of the refrigerant is attached to the inlet side of the evaporator, the time when the temperature of the evaporator reaches a predetermined value is detected by the temperature detector, and when the time exceeds a predetermined time, A method for preventing generation of incomplete ice in a water circulation type ice making machine, which temporarily closes the electromagnetic valve for a refrigerant or the expansion valve. 6. An end of the refrigeration pipe is led out from the refrigeration circuit at the inlet side of the refrigerant solenoid valve, the other end is connected to the outlet side of the expansion valve, and an auxiliary solenoid valve is provided in the refrigeration pipe. , When the refrigerant solenoid valve or the expansion valve is closed,
The method for preventing generation of incomplete ice according to claim 4, wherein the auxiliary electromagnetic valve is opened. 7. The length of time from the closing of the solenoid valve for refrigerant or the expansion valve to the reopening of the valve and the length of time from the opening of the auxiliary solenoid valve to the reclosing of the auxiliary solenoid valve. The method for preventing the generation of incomplete ice according to claim 6, wherein is controlled by a cotton ice prevention timer. 8. The low-pressure pressure switch is attached to the refrigeration circuit, and the low-pressure pressure switch operates even when the operating pressure of the low-pressure pressure switch is reached when the refrigerant solenoid valve or the expansion valve is closed. The method for preventing the generation of incomplete ice according to claim 5, wherein the method of disabling ice is disabled. 9. During the ice making cycle, in the ice making water circuit, the ice making water is circulated and supplied to the ice making plate by a circulation pump, and in the refrigerating circuit, an evaporator in a heat exchange relationship with the ice making plate is provided with a compressor. In order to prevent the generation of incomplete ice in a water circulation type ice making machine that circulates and supplies the refrigerant through a solenoid valve for the refrigerant, a time measuring means for measuring the time from the start of the ice making cycle, and a circulation supply. Detecting means for detecting the temperature of the ice-making water being operated, and when the time until the ice-making water is cooled to a predetermined temperature exceeds a predetermined time, the circulation pump is stopped or the refrigerant solenoid valve is closed. A device for preventing generation of incomplete ice in a water circulation type ice making machine, which is provided with a control device for temporarily operating a valve.