JP2018071847A - Method of operating cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that if a compressor is started while an initial temperature of water in a liquid container as typified by a cooling cylinder of an auger type ice-making machine is kept high, excessive large cooling load makes it difficult to lower refrigerant pressure of a refrigeration circuit so as to continue a state where load on the compressor is large and continuing the state causes an overcurrent to flow in the compressor so as to stop operation of the compressor.SOLUTION: In a method of operating a cooling system including: a compressor 32 for compressing a refrigerant; a condenser 34 for condensing the refrigerant from the compressor 32; expansion means 36 for expanding the volume of the refrigerant from the condenser 34; an evaporator 18 for performing heat exchange by using the refrigerant from the expansion means 36; and a liquid container 14 for storing liquid to be cooled by the evaporator 18, the compressor 32 is started to start cooling operation and after required time elapses after start of the cooling operation, liquid is supplied to the liquid container 14.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an operation method of a cooling system, and more particularly, in a cooling device that obtains a cooling liquid or ice by cooling a liquid in a liquid container by an evaporator that forms a part of the refrigeration circuit. It is related with the operating method of the cooling system which reduced cooling and was able to achieve cooling economically.

  For example, an auger type ice making machine or a cooled beverage dispenser cools a liquid stored in a liquid container by an evaporator from a refrigeration circuit so that the liquid is frozen or cooled to a temperature suitable for drinking. It has become. Since the present invention relates to the improvement of the cooling system operation method used in the apparatus for cooling the liquid in the liquid container, first, the liquid cooling apparatus will be described by taking an auger type ice making machine as an example.

  FIG. 7 shows a schematic configuration of the auger type ice making machine 10. In a cylindrical liquid container (hereinafter also referred to as “cooling cylinder”) 14 surrounded by a heat insulating material 12, an opening 20 opened at the bottom thereof is shown. Water (liquid) from the liquid reservoir 21 is supplied through the supply pipe 22. On the outside of the cylindrical liquid container 14, an evaporator 18 led out from a refrigeration circuit 16 described later is tightly wound. A spiral auger blade 26 is concentrically inserted into the liquid container 14, and a rotary shaft 28 provided below the auger blade 26 is rotationally driven in one direction by a motor 30 having a speed reduction mechanism. It has become so. The auger blade 26 has a scraping blade formed on its spiral periphery.

  Further, a head 31 as a fixed blade is disposed above the liquid container 14, and the ice pieces scraped by the auger blade 26 are compressed and then cut into a predetermined length to form a fine ice block. Above the head 31 in the liquid container 14 communicates with a discharge pipe 33 that discharges the obtained ice block and sends it to an ice stocker (not shown). Further, the liquid reservoir 21 arranged on the right side of FIG. 7 is provided with a water level sensor 35 for detecting the water level of the stored liquid (water in this specification), and outputs water level detection information to a control circuit (not shown). doing.

  The refrigeration circuit 16 shown in FIG. 7 includes a compressor 32 that compresses the refrigerant, a condenser 34 that cools and condenses the compressed refrigerant at a high temperature, and expansion means 36 that expands the condensed refrigerant by volume. The evaporator 18 and these members are connected by the pipe line 38 in the order described above to constitute a refrigerant circulation system. Reference numeral 40 indicates a fan motor for air-cooling the condenser 34. The expansion means 36 uses a capillary tube in the illustrated example, but may be an expansion valve composed of an on-off valve.

  When the compressor 32 in the refrigeration circuit 16 is started, the high-temperature refrigerant compressed and liquefied by the compressor 32 flows through the pipe line 38 and flows into the condenser 34, where it is cooled and then expanded. 36. The refrigerant expands in volume at the outlet of the expansion means 36 to become a vaporized refrigerant, and heat is exchanged in the evaporator 18 to cool the liquid in the liquid container 14. Further, the auger blade 26 rotates while maintaining a slight gap with respect to the inner wall of the cooling cylinder 14 by starting the motor 30 and rotating the rotary shaft 28. Further, water stored in the liquid reservoir 21 is supplied from the bottom to the liquid container 14 via the supply pipe 22, and this water rises inside the liquid container 14 and fills up to the water level of the liquid reservoir 21. . Since the outer wall of the liquid container 14 is cooled to 0 ° C. or less through the evaporator 18 by the operation of the refrigeration circuit 16, the water in contact with the inner wall of the liquid container 14 freezes and grows as an ice layer. . The auger blade 26 located inside the liquid container 14 scrapes off the ice layer formed on the inner wall of the liquid container 14 as it rotates, and conveys it upward as the auger blade 26 rotates. Then, the conveyed ice is compressed by the head 31 located above the auger blade 26 into an ice lump, sent to the discharge pipe 33 and discharged to an ice stocker, a beverage cup or the like.

JP 2010-32203 A

  In the auger type ice making machine 10 described above, the temperature of the water present in the liquid container 14 cooled by the evaporator 18 becomes the cooling load of the refrigeration circuit 16. By the way, when the auger type ice making machine 10 is first operated, the initial temperature of the water stored in the liquid reservoir 21 may be considerably high in summer. This means that the cooling load of the refrigeration circuit 16 on the liquid container 14 supplied with water from the liquid reservoir 21 is large. Therefore, if the compressor 32 is started and the operation of the refrigeration circuit 16 is started while the initial temperature of water remains high, the refrigerant load in the refrigeration circuit 16 does not drop easily because the cooling load is too large. The state where the load on the machine 32 is large continues. If this state continues, an overcurrent flows in the motor that drives the compressor 32, and an overcurrent detector (none of which is shown) may be activated to stop the operation of the compressor 32.

  The above state will be described with reference to the time chart of FIG. Conventionally, when the compressor 32 is driven, water to be cooled already exists in the liquid container 14. When the compressor 32 is started, the temperature of the water stored in the liquid container 14 gradually decreases as shown in FIG. Further, the current value of the motor that drives the compressor 32 gradually decreases due to a decrease in cooling load accompanying a decrease in water temperature. However, as described above, when the initial temperature of water in the liquid container 14 is high, the water temperature only gradually decreases, so that the compressor 32 continues to have a large cooling load. For this reason, the motor overcurrent in the compressor 32 continues for a certain period of time, and the overcurrent value indicated by the one-dot broken line in FIG. 2 cannot be cleared within a certain period of time, and the overcurrent finally exceeds the threshold value. As a result, the compressor 32 stops. In order to prevent such a situation, even when the initial temperature of water is high, it is necessary to lower the water temperature as quickly as possible so that the refrigerant pressure in the refrigeration circuit 16 quickly decreases. In order to meet this demand, a compressor having a larger capacity has to be adopted, which means an increase in the cost of the compressor and the electricity cost, which is extremely uneconomical.

  In order to solve the above-mentioned problem inherent in the cooling system attached to the container of the liquid to be cooled, the water from the liquid reservoir is started after a predetermined time has elapsed after starting the compressor in the refrigeration circuit. An operation method is proposed in which a pressure drop in the refrigeration circuit is promoted by supplying a liquid container. That is, as shown in the time chart of FIG. 2, when water is present in the liquid container 14 when the compressor 32 is started up and the initial temperature of the water is high, the water temperature of the liquid container 14 is the refrigeration. The circuit 16 becomes a large cooling load. For this reason, the overcurrent duration of the compressor 32 in the refrigeration circuit 16 becomes longer, and eventually the operation is stopped after a certain time. Therefore, as shown in FIG. 1, if the inventor supplies water to the liquid container 14 after a predetermined time with respect to the start of the compressor 32, the refrigerant pressure drop in the refrigeration circuit 16 is promoted. This is what we found.

In order to solve the problem and achieve the intended object, the invention according to claim 1
A compressor that compresses the refrigerant, a condenser that condenses the refrigerant from the compressor, expansion means for volume expansion of the refrigerant from the condenser, and an evaporator that performs heat exchange with the refrigerant from the expansion means, In the operation method of the cooling system comprising a liquid container for storing the liquid to be cooled by the evaporator,
The gist of the invention is that the compressor is started to start the cooling operation, and the liquid is supplied to the liquid container after a required time has elapsed from the start of the cooling operation.
According to the first aspect of the present invention, even when the initial temperature of the liquid in the liquid container is high, the liquid is supplied to the liquid container after the refrigerant pressure in the cooling circuit is lowered. An overcurrent does not flow and the operation of the compressor is not stopped.

The gist of the invention described in claim 2 is that the supply of the liquid to the liquid container is gradually increased.
According to the second aspect of the present invention, even when the temperature of the liquid in the liquid container is considerably high, the supply of liquid to the liquid container is gradually increased, so that an overcurrent flows through the motor of the compressor. The compressor will not stop operating.

In the invention according to claim 3, the supply of the liquid to the liquid container is gradually increased after the temperature of the liquid container or the liquid in the liquid container falls below a preset threshold value. The gist.
According to the invention of claim 3, even when the temperature of the liquid in the liquid container is extremely high, the liquid container or the temperature of the liquid in the liquid container becomes equal to or lower than a predetermined value before the liquid container Since the liquid is gradually supplied, no overcurrent flows through the motor of the compressor, and the operation of the compressor is not stopped.

  According to the present invention, even when the initial temperature of the liquid existing in the liquid container such as the cooling cylinder of the auger type ice making machine is high, the liquid is supplied to the liquid container after the refrigerant pressure in the refrigeration circuit is lowered. By doing so, it is possible to prevent an inconvenient situation where an overload current flows through the compressor and stops.

It is a time chart which shows the operating condition of the auger type ice making machine at the time of implementing the operating method of the cooling system which concerns on Example 1 of this invention. It is a time chart which shows the conventional driving | running state in the auger type ice making machine shown in FIG. It is a time chart which shows the operating method of the cooling system which concerns on Example 2 of this invention. It is a time chart which shows the fault inherent in the operating method of the cooling system concerning Example 1 of the present invention. It is a time chart which shows the operating method of the cooling system which concerns on Example 3 of this invention. It is a time chart which shows the fault inherent in the operating method of the cooling system concerning Example 2 of the present invention. It is explanatory drawing which shows schematic structure of the auger type ice making machine in which the liquid exists in a cooling cylinder.

  Next, the operation method of the cooling system according to the present invention will be described with reference to the drawings with preferred embodiments. The cooling system to which the cooling system operation method is applied is exemplified by the auger type ice making machine described with reference to FIG. 7, but a tank for storing ice making water is provided and ice making water is supplied from the water tray to the ice making room. The so-called closed cell type ice making machine or the so-called open cell type ice making machine not having the water tray may be used. That is, the liquid container for storing the liquid to be cooled in the present invention is a cooling cylinder in an auger type ice making machine, and an ice making water tank in a closed cell type or open cell type ice making machine. Further, a cooling beverage dispenser that cools the liquid in the container by bringing the evaporation tube into close contact with the outer periphery (or inner periphery) of the liquid container and allowing the beverage to pass through the coiled serpentine immersed in the cooling liquid. In that case, the liquid container containing the serpentine tube corresponds to this.

[Example 1]
The cooling system operating method according to the first embodiment of the present invention will be described with reference to the time chart of FIG. As described above with reference to FIG. 2, conventionally, when the compressor 32 of the refrigeration circuit 16 is started, water is already present in the cooling cylinder 14. However, in the invention according to the first embodiment, as shown in FIG. 1, when the operation of the auger type ice making machine 10 is started and the compressor 32 is started, water is not supplied to the cooling cylinder 14 but is emptied. Keep it. Then, since there is no water in the cooling cylinder 14, the cooling cylinder 14 is gradually cooled by the evaporator 18 by the cooling operation started by starting the compressor 32, but the cooling load is extremely high. It becomes light. Then, when the required time elapses after the compressor 32 is started and the refrigerant pressure in the refrigeration circuit 16 is lowered, water is supplied from the liquid reservoir 21 into the cooling cylinder 14 as shown in FIG. As shown in FIG. 7, the supply pipe 22 that communicates the opening 20 of the cooling cylinder 14 and the liquid reservoir 21 is provided with an open / close valve 41 that is controlled to open and close by a control circuit.

  Thus, the compressor 32 of the refrigeration circuit 16 is started first, and after the time (predetermined time) necessary for the refrigerant pressure in the refrigeration circuit 16 to drop to a predetermined value has passed, the on-off valve 41 is opened. Then, water is supplied to the cooling cylinder 14. That is, by decreasing the refrigerant pressure in the refrigeration circuit 16, the current value of the motor that drives the compressor 32 decreases smoothly as shown in FIG. Even after a lapse of time, the compressor 32 does not stop because the overcurrent threshold is not reached. Further, when the on-off valve 41 opens after a predetermined time and begins to supply water to the cooling cylinder 14, the current value of the compressor 32 slightly increases. However, since the cooling cylinder 14 has already been cooled by the evaporator 18, the water supplied to the cooling cylinder 14 immediately drops in temperature, so that the refrigerant pressure in the refrigeration circuit 16 also decreases, and therefore the current of the compressor 32 is reduced. The value starts to fall again. That is, by performing the operation control of the cooling system shown in FIG. 1, the refrigerant pressure in the refrigeration circuit 16 steadily decreases even when the initial temperature of the water flowing into the cooling cylinder 14 is high. The problem that the operation of the compressor 32 is stopped due to overcurrent due to overcurrent is preferably solved. For this reason, it is not necessary to use a large-capacity compressor 32, and the manufacturing cost and power consumption can be reduced, which is economical.

[Example 2]
The invention of the first embodiment described above is an excellent technique, but when the initial temperature of the water supplied to the cooling cylinder 14 is considerably high, the water is supplied after a predetermined time from the start of the compressor 32. Even if the time difference control is performed, the refrigerant pressure in the refrigeration circuit 16 may not be sufficiently reduced, and the compressor 32 may stop due to overcurrent detection. That is, when the invention of the first embodiment is implemented, if the water temperature is considerably high, the refrigerant pressure in the refrigeration circuit 16 is expected even if water is supplied to the cooling cylinder 14 with a time difference as shown in FIG. The overcurrent flowing through the motor of the compressor 32 exceeds the threshold and stops.

  The invention according to the second embodiment has been proposed to cope with such a case, and as in the first embodiment, the water is supplied to the cooling cylinder 14 with a predetermined time delay from the start of the compressor 32. The same. However, as shown in FIG. 3, water is supplied to the cooling cylinder 14 with a time difference after the compressor 32 is started. As a water supply mode, the water is supplied to the cooling cylinder 14 every predetermined time. Increase the water supply step by step. As means for gradually increasing the amount of water, it is proposed to control the frequency of the opening / closing operation of the opening / closing valve 41 and the length of the opening / closing time of the opening / closing valve 41 by a control circuit (not shown). Further, the amount of water supply may be increased stepwise, or may be changed linearly or with a quadratic curve.

  That is, in the second embodiment, as shown in FIG. 3, water is supplied to the cooling cylinder 14 with a predetermined time difference after the compressor 32 is started. By doing so, the cooling load of the refrigeration circuit 16 is controlled to increase little by little (not to increase at once). As a result, the current value of the motor in the compressor 32 fluctuates in response to the stepwise supply of water as shown in FIG. 3, but reaches the overcurrent indicated by the horizontal alternate long and short dash line in the figure. There is no. Therefore, the motor of the compressor 32 does not stop due to overcurrent detection.

Example 3
The invention of the second embodiment described above is also an excellent technique. However, when the initial temperature of the water flowing into the cooling cylinder 14 is extremely high, the refrigerant pressure of the refrigeration circuit 16 can be obtained even if the operation method described in FIG. However, the compressor 32 may stop due to overcurrent detection. For example, even if the operation method of the second embodiment is performed as shown in FIG. 6, when the initial temperature of water in the cooling cylinder 14 is extremely high, every time the compressor 32 is started up, it is gradually supplied with a time difference. Since the water temperature in the cooling cylinder 14 rises, the water temperature as a whole does not decrease easily. Therefore, the refrigerant pressure in the refrigeration circuit 16 does not sufficiently decrease, and an overcurrent flows to the motor of the compressor 32. It will stop.

  The invention according to the third embodiment is proposed to cope with such a case, and the temperature of the cooling cylinder 14 cooled by the evaporator 18 or the temperature of the water stored in the cooling cylinder 14 is determined. When detected by a temperature detection means (not shown) and the detected temperature falls to a predetermined value, as shown in FIG. The cooling load is controlled to increase gradually. Thereby, even when the initial water temperature of the water flowing into the cooling cylinder 14 is extremely high, the temperature of the cooling cylinder 14 or water is detected by the temperature detecting means in advance, so that the cooling cylinder 14 is sufficiently Since the water flowing in stepwise is cooled immediately because it is cooled, it is economical because it is not necessary to replace the capacity of the compressor 32 with a larger one.

14 liquid containers (cooling cylinders), 18 evaporators, 32 compressors, 34 condensers,
36 Expansion means

Claims (3)

A compressor (32) for compressing the refrigerant, a condenser (34) for condensing the refrigerant from the compressor (32), and an expansion means (36) for volume expansion of the refrigerant from the condenser (34), In an operating method of a cooling system comprising an evaporator (18) that exchanges heat with refrigerant from the expansion means (36), and a liquid container (14) that stores liquid to be cooled by the evaporator (18). ,
A cooling system, wherein the compressor (32) is started to start a cooling operation, and a liquid is supplied to the liquid container (14) after a lapse of a required time from the start of the cooling operation. how to drive.   The method of operating a cooling system according to claim 1, wherein the supply of liquid to the liquid container (14) is gradually increased.   The supply of liquid to the liquid container (14) is gradually increased after the temperature of the liquid in the liquid container (14) or the liquid container (14) falls below a preset threshold value. The operation method of the cooling system according to 1 or 2.

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