KR20210126275A - Ice slurry production system - Google Patents

Abstract

The present invention relates to an ice slurry production system. The ice slurry production system according to one embodiment may comprise: a tank for storing a working fluid; a main circulation pump supplying the working fluid stored in the tank to an ice maker; the ice maker receiving the working fluid and producing an ice slurry; and a recirculation pump for recirculating a predetermined flow rate from an outlet of the ice maker to an inlet of the ice maker. An objective of the present invention is to provide the ice slurry production system capable of producing the ice slurry having a high IPF.

Description

Ice slurry production system {ICE SLURRY PRODUCTION SYSTEM}

The following embodiment relates to an ice slurry production system.

Ice slurry, which is one of the phase change materials, is a mixture of ice (solid) and aqueous solution or water (liquid), and is known as a heating medium having many advantages in the fields of storage and transport of cold heat and direct cooling of food. Recently, ice slurry has been developed mainly for contact cooling seawater ice maker rather than energy storage or transportation due to problems such as capacity, efficiency, and price of ice maker. However, even in this field, it is difficult to obtain ice slurry of high IPF required for contact cooling, so it is limitedly used where a special purpose contact cooling device is required.

Conventionally, in order to obtain a high IPF, 4 to 8 multiple ice makers are connected in series as shown in FIG. 2 or ice slurry obtained by using various types of ice makers as shown in FIG. 3 is converted into a high IPF by using a stirrer in a stirred tank It was mainly used in the way it was made. However, due to the complicated structure of such a system, lack of reliability in operation, high price, and inconvenience in use, it is a major cause of limited use of ice slurry despite its excellent performance and effectiveness.

Accordingly, there is a need for an ice slurry production system capable of producing ice slurry having a high IPF, having a simple structure, and securing operational reliability.

The above-mentioned background art is possessed or acquired by the inventor in the process of deriving the disclosure of the present application, and it cannot be said that it is necessarily known technology disclosed to the general public prior to the present application.

An object of one embodiment is to provide an ice slurry production system capable of producing an ice slurry having a high IPF.

An object of one embodiment is to provide an ice slurry production system that can variably implement various IPFs.

An object of one embodiment is to provide an ice slurry production system having a simple structure and high reliability.

An ice slurry production system according to an embodiment includes a tank for storing a working fluid; a main circulation pump supplying the working fluid stored in the tank to an ice maker; the ice maker receiving the working fluid and producing ice slurry; and a recirculation pump for recirculating a predetermined flow rate from the outlet of the ice maker to the inlet of the ice maker.

The control unit may further include a control unit for controlling the main circulation pump and the recirculation pump to vary an IPF (Ice Packing Factor) of the ice slurry.

The controller may operate the recirculation pump to improve the IPF of the ice slurry to 20% or more.

In the process of changing the IPF of the ice slurry, the controller may first control the main circulation pump to secure a new flow rate and head, and then operate the recirculation pump.

The ice maker may include at least one of a sealed single-tube ice maker, a sealed multi-tube ice maker, and a sealed disc-type ice maker.

The main circulation pump may be a type in which a plurality of pumps are connected in parallel, or a pump having an inverter.

The ice slurry production system according to an embodiment may produce ice slurry having a high IPF by including a recirculation pump.

The ice slurry production system according to an embodiment may variably implement various IPFs through the control of the main circulation pump and the recirculation pump.

The ice slurry production system according to an embodiment may have a simple structure and high reliability.

Effects of the ice slurry production system according to an embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic diagram of a conventional ice slurry production system.
2 is a schematic diagram of a conventional ice slurry production system for increasing IPF.
3 is a schematic diagram of a conventional ice slurry production system for increasing IPF.
4 is a schematic diagram of an ice slurry production system according to an embodiment.
5 is a schematic diagram of an ice slurry production system according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the patent application is not limited or limited by these embodiments. It should be understood that all modifications, equivalents and substitutes for the embodiments are included in the scope of the rights.

The terms used in the examples are used for description purposes only, and should not be construed as limiting. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description with reference to the accompanying drawings, the same components are given the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In the description of the embodiment, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the components from other components, and the essence, order, or order of the components are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but another component is between each component. It will be understood that may also be "connected", "coupled" or "connected".

Components included in one embodiment and components having a common function will be described using the same names in other embodiments. Unless otherwise stated, a description described in one embodiment may be applied to another embodiment, and a detailed description in the overlapping range will be omitted.

1 is a schematic diagram of a conventional ice slurry production system. 2 is a schematic diagram of a conventional ice slurry production system for increasing IPF. 3 is a schematic diagram of a conventional ice slurry production system for increasing IPF.

Ice slurry is currently produced in the following production method.

1) There is a method to obtain ice slurry by scraping the cooling heat transfer surface in various ways. This method is the most used method, and is used in various fields due to various characteristics. The scraping method includes an ice maker having a single heat exchange and ice making channel and an ice maker having multiple channels capable of expanding capacity. Most ice makers used for cooling food are single-channel type and have a small capacity, and are used for direct contact cooling of food using seawater or the like.

The multi-channel ice maker includes the ORE method using a whip rod, the spiral scraper method, and the disk method. They have different characteristics and can be expanded to a relatively large capacity. Although it is used for direct contact cooling, it is also used for various purposes such as heat storage and process.

The scraping method is a way to obtain a relatively high IPF, and can have an IPF of as little as 4% to as much as 15% in one cycle. Depending on the type of circulation, there is a method having a closed circuit and a method having an open circuit. Since the method having an open circuit is a method in which the ice slurry produced by gravity is mainly dropped into the tank, a separate stirred tank or the like must be used to transfer the ice slurry to a pump and use it.

2) There is a method of producing ice slurry using the supercooling phenomenon, which is an inherent characteristic of water. It is a method of obtaining ice slurry while relieving supercooling by making non-freezing water below freezing point and applying shock to it in various ways. It was mainly researched and developed in Japan. In the case of an open circulation system, there is a difficulty in continuously removing many dust particles exposed to the air, so it has been changed to a closed circulation system, but the difficulty of continuously maintaining an unstable state lowers reliability. In addition, it is difficult to obtain a high IPF, so it is only used very limitedly in recent years.

3) In addition to these, a method of producing ice slurry at a temperature below the triple point by evaporating water in a vacuum chamber. A method of obtaining ice slurry, a method of obtaining ice slurry by circulating suspended particles with a specific gravity similar to that of water with a diameter of 1 to 3 mm inside the heat transfer tube at high speed and exchanging heat with the refrigerant outside the heat transfer tube, pressurized with high pressure Various methods of ice making have been developed, such as a method of obtaining ice slurry by relieving pressure when the temperature is below a certain level by cooling in a refrigerator.

In order to actually use ice slurry, ice slurry of various IPF is required depending on the purpose. In most cases, the higher the IPF of the ice slurry produced by the ice maker, the higher the usefulness. In addition, if the ice maker can produce high IPF ice slurry directly from the ice maker with a closed structure, the usefulness will be even greater.

For ice slurry required for direct contact cooling of food such as seafood, an IPF of at least 15% is required. If such ice slurry cannot be obtained from an ice maker, a stirring tank or a conentrater must be used outside the ice maker, or multiple ice makers must be connected in series. This problem is the biggest constraint that limits the spread of the ice slurry system. Not only economical issues, but also the installation area, the difficulty of using equipment, frequent defects and short lifespan due to the increase in defect factors greatly limit the competitiveness of the ice slurry system, thus limiting its distribution despite its many advantages.

In the thermal storage system, since most of the simple thermal storage uses simple separation and use of particles and aqueous solution in the thermal storage tank, which can relatively reduce the IPF restrictions, they have been used without much limitation. However, when long-distance cold-heat transportation is required or when direct circulation of ice slurry is required, there is a difficulty in using both a complicated stirring device and a heat storage tank or using the entire heat storage tank as a stirred tank.

Here, if the ice slurry having a high IPF can be directly produced by an ice maker having a closed circuit that can simplify the ice slurry supply system, such an ice slurry production system has more possibilities for cold and heat transport. In a structure having an open circulation system, another device must be used for direct transport of the ice slurry, and this configuration also greatly reduces the competitiveness and reliability of the system.

On the other hand, as for the method of increasing the IPF of ice slurry, about four methods are known so far, and two or three methods are used among them. Among these, the most effective method is to increase the IPF during the ice making process. With the minimum flow rate required for circulation, more than 15% of ice slurry can be made by using gravity to flow down inside a large-diameter cylindrical evaporator. These are collected in a tank and transferred to a slurry pump for use, or dropped from the top of the storage tank and filled in the tank for use.

If it is dropped into the tank, only the aqueous solution is continuously circulated at the bottom of the tank to make accumulated ice, so the IPF in the tank can be up to 60% ice slurry. If a higher IPF is required or it is intended to be transported and used, a transport device including a separate stirring device and an aqueous solution separation device are required.

As another method, as shown in FIG. 2 , a method of obtaining an ice slurry having a high IPF by connecting several ice makers in series is used. In the case of a single tube ice maker, this method is mostly used for cooling seafood or food. A method is used to obtain ice slurry with an IPF of 20-40% by directly cooling seawater at 15-20°C using as few as three to as many as eight ice makers in series. The maximum IPF achievable depends on the inlet and outlet structure of the ice maker and up to 40% of the ice slurry can also be fed in this way. However, it requires a high-lift pump, has many moving parts, so reliability is low, and production cost is high, which is a big factor limiting the spread of ice slurry system.

In the case of an ice-making system that directly cools seawater at 15°C to obtain an ice slurry with an IPF of 40%, it is almost impossible to operate a stable operation because the circulating flow rate is too low as the heat exchanger performs heat exchange under the condition of an inlet/outlet temperature difference of 47 K. In particular, the ice slurry ice maker is a heat exchange device that involves a phase change, and ice slurry is separated from the ice particles and aqueous solution at a flow rate below a certain flow rate. there is no problem

As shown in FIG. 3 , the method using a stirred tank can obtain a relatively high IPF, but the stirred tank itself becomes a complex device, and operation is very difficult. Controlling the amount entering and leaving the tank is more difficult. In order to obtain a constant IPF, it is difficult to obtain a constant IPF in that the amount used and the incoming amount must be the same, and the amount of particle ice contained in it must also be the same. Moreover, there is a constraint that the ice maker connected to the agitator to supply the ice slurry to the tank must have a structure in which the high IPF ice slurry can circulate, so it is difficult to obtain a constant IPF in the actual stirring device.

The failure of the direct ice slurry circulation system using a shell-and-tube heat exchanger attempted in Europe in the early 2000s was a mistake in not understanding the characteristics of such a stirred tank, leading to distrust of the ice slurry system and greatly limiting the spread of the direct transportation system. resulted in It is known that the separation space of particle ice and aqueous solution connected to the stirring device is not easy to completely separate particle ice, even if it is a precisely designed separation space. If the ice maker connected to the agitation tank is not structured to circulate ice particles or high IPF ice slurry, it is a general assessment that the agitator or tank has no choice but to send the pre-produced ice slurry by stirring. In this case, it is very difficult to continuously obtain an ice slurry of a constant IPF.

Attempts to increase the IPF have been made experimentally by separating and extracting the aqueous solution in the ice slurry from the particle ice through a filter during the circulation of the ice slurry without using a stirring tank, but there are not many commercialized cases yet. The IPF that can be obtained may be limited in that the circulation is made by the lift of the pressure formed by the circulation exiting the filter after concentration. It is judged that higher IPF is possible by adding a forced circulation device. In this case, this device also becomes a single facility, making it difficult to manage and maintain.

In view of this point, it can be easily judged that the usefulness of the ice making method, which uses a closed circulation system and can increase IPF at the same time, is great. However, it is not easy to increase the IPF in an ice machine. A method of producing an ice slurry having a high IPF in an ice maker having a closed circulation structure is accompanied by many difficulties. In particular, this difficulty is further aggravated in the multi-channel type ice maker used in the medium and large capacity ice maker.

In conclusion, in order to obtain an ice slurry with high IPF from the multi-channel ice maker, the basicly necessary flow rate that can circulate without phase separation and the removal of the recirculation area inside the water chamber by equal flow, and partial phase separation that can be achieved nonetheless It is necessary to stir in the water chamber to remove it. In addition, the flow rate and lift of the ice slurry circulating in the ice maker, which is the premise of this flow, are absolutely necessary. Under these conditions, the multi-tube ice maker generally has a lower IPF than the single-tube ice maker. This is because the multi-channel ice maker inevitably has problems with circulation under the condition that the flow rate should be low during the heat exchange process.

In addition, this problem is not only a problem in the outlet water chamber, but also in the inlet water chamber, when the flow rate is low, it is difficult to achieve even distribution.

The present invention is designed to obtain high IPF ice slurry from a small volume to a large capacity by a simple method in such a situation.

With the present invention, one ice making system can produce ice slurry of 5 to 30% IPF in a capacity range of 3 to 1,500 usRT based on the ice making capacity in a simple way using a pump, and it can be produced while arbitrarily and constantly adjusting the required IPF. A system that can do this has become possible. In addition, if a pump with a special function is used and the structure of the water chamber is improved, even high IPF ice slurry can be produced directly from the ice machine.

Such an ice making system is a method that can solve the problems of capacity limitation, low efficiency, high cost, and low reliability of the current ice slurry ice making apparatus at once. In addition, this type of ice slurry ice making system will greatly enhance competitiveness in food cooling applications, where ice slurry systems are currently mainly used, by improving economic efficiency, overcoming capacity limitations, and improving operation efficiency. It will be able to recover its role as a heat energy transport medium. Furthermore, it will be possible to expand the possibility of being used in areas such as desalination, juice concentration, snow removal, etc.

4 is a schematic diagram of an ice slurry production system according to an embodiment. 5 is a schematic diagram of an ice slush production system according to an embodiment.

4 and 5 , the ice slurry production system 1 according to an embodiment recirculates a predetermined flow rate from the outlet of the ice maker 13 to the inlet, thereby producing ice slurry having a high IPF (Ice Packing Factor). can In addition, the ice slurry production system 1 can produce ice slurry of various IPFs through the control of the main circulation pump 12 and the recirculation pump 14 .

The ice slurry production system 1 according to an embodiment may have a closed circulation structure. The ice slurry production system 1 may include a tank 11 , a main circulation pump 12 , an ice maker 13 , a recirculation pump 14 , and a controller (not shown).

The tank 11 may receive a working fluid from the outside and store the supplied working fluid. The main circulation pump 12 may circulate the working fluid. Specifically, the main circulation pump 12 may supply the working fluid stored in the tank 11 to the ice maker 13 . The ice maker 13 may be supplied with a working fluid to produce ice slurry. The recirculation pump 14 may recirculate a predetermined flow rate from the outlet of the ice maker 13 to the inlet of the ice maker 13 . The control unit may control the main circulation pump 12 and the recirculation pump 14 . The control unit may change the IPF of the ice slimer through the control of the main circulation pump 12 and the recirculation pump 14 . Specifically, the control unit operates the recirculation pump 14 to ensure a constant flow rate and lift that flows inside the ice maker 13, thereby improving the IPF of the ice slurry to 20% or more, and, if necessary, to 30% or more. According to the recirculation loop using the recirculation pump 14 , the flow rate and lift circulating to the ice maker 13 can be secured, so it may be possible to improve the IPF of the ice slurry.

The ice slurry discharged to the outlet of the ice maker 13 may be supplied to a place of use or may be returned to the tank 11 and recirculated. An ice slurry flow meter and a flow path control valve may be provided in the line through which the ice slurry is supplied to the place of use and the line through which the ice slurry is returned to the tank 11 .

The ice maker 13 may be supplied with a working fluid to produce ice slurry. The ice maker 13 may include at least one of a sealed single-tube ice maker, a sealed multi-tube ice maker, and a sealed disc-type ice maker.

In the case of the closed single tube type ice maker, since the structure of the inlet and the outlet is simple, if a certain flow rate is secured, even if the ice slurry of 30% IPF level is introduced into the ice maker 13, there may be no circulation problem. When using a closed single tube type ice maker, it may be desirable to use an ice maker with a high maximum capacity in order to overcome the capacity limitation of the ice maker.

In the case of the closed multi-tubular ice maker, a stirring device may be provided so that a predetermined flow rate can be evenly distributed at the inlet. By providing the stirring device, it is possible to prevent clogging by recirculation or dead space of the flow. Through agitation in the water chamber, an even flow can be generated, thereby ensuring that the high IPF ice sludge is smoothly discharged to the outlet.

On the other hand, as the IPF increases, in order to smoothly continue the discharge of the ice slurry, an additional flow rate and head may need to be secured. To this end, the recirculation pump 14 may be driven. As the recirculation pump 14 recirculates a predetermined flow rate and head from the outlet of the ice maker 13 to the inlet, the ice maker 13 can be operated without clogging, and the IPF can be increased.

The higher the IPF, the higher the lift and flow rate of ice slurry is required. In particular, an IPF of 30% or more may require a sharply high flow rate and lift. The main circulation pump 12 may maintain a flow rate circulated to the outside so that a predetermined IPF or less is maintained. The main circulation pump 12 may preferably be a pump having a large head change according to a change in flow rate.

The main circulation pump 12 for discharging the ice slurry to the outside may be configured in a manner capable of controlling the flow rate and the head. For example, the main circulation pump 12 may be a type in which a plurality of high-head pumps are connected in parallel. Alternatively, the main circulation pump 12 is a pump equipped with an inverter, and may change the IPF by changing the flow rate while maintaining the lift required for the ice maker 13 .

When the main circulation pump 12 is controlled by an inverter, the discharge head can be controlled in a range exceeding the lift increased by the flow rate formed by the recirculation pump 14 and the flow rate change added to the lift for discharge. That is, in order to achieve stable operation of the ice maker 13, the flow rate and the lift formed by the operation of the recirculation pump 14 must be added to the increased lift at the same time. It may be desirable to control over a frequency that can be secured.

In addition, in order to obtain various IPFs, it is necessary to circulate a flow rate of a certain amount or more in the ice maker 13 and to be able to change the flow rate of the main circulation pump 12 . Therefore, it may be preferable that the main circulation pump 12 be a pump having a characteristic capable of responding to a lift of the head due to an increase in the circulation flow rate inside the ice maker 13 .

On the other hand, due to a change in the frequency of the main circulation pump 12, the flow rate changes in proportion to the square of the number of revolutions, and the head changes greatly in proportion to the cube of the number of revolutions, so that a mismatch between the flow rate and the head value may occur. In this case, it may be desirable to counteract this by increasing the system-wide pressure drop.

When the main circulation pump 12 is composed of a plurality of pumps connected in parallel, the plurality of pumps may be configured with different capacities in consideration of a flow rate decrease due to an increased head according to an increased flow rate.

The ice slurry production system 1 can variably implement a low IPF operation and a high IPF operation. In the case of the low IPF ice making operation, ice may be made using the flow rate and the head of the main circulation pump 12 so that continuous ice making of the low IPF ice slurry is possible only by circulation of the main circulation pump 12 . When a high IPF deicing operation is required, the recirculation pump 14 may be additionally operated to circulate at a flow rate and head required to obtain a target IPF. Accordingly, as the flow rate of the main circulation pump 12 is reduced by the increased head, the IPF discharged to the outside of the ice maker may increase. At this time, the main circulation pump 12 must be able to maintain a head of greater than or equal to the pressure drop that rises while the change in flow rate is large due to the change in head. When the inverter is applied to the main circulation pump 12, an appropriate flow rate and lift can be obtained by varying the number of revolutions, but since the lift reduction rate is much greater than the flow rate reduction, a separate flow control valve is further provided outside the ice maker 13 can be

On the other hand, during a high IPF ice making operation, a flow rate and a lift capable of sufficiently circulating the generated ice slurry are required. To this end, the controller may first control the main circulation pump 12 to secure a new flow rate and lift first, and then operate the recirculation pump 14 . For example, the control unit first controls the main circulation pump 12 so that the head of the main circulation pump 12 does not become insufficient when the recirculation pump 14 is operated in the process of changing the IPF of the ice slurry to obtain a newly formed flow rate and lift. In this first secured state, the recirculation pump 14 can be operated. For example, in the case of using an inverter, the control unit may first perform frequency adjustment of the inverter and operate the recirculation pump 14 .

As described above, although the embodiments have been described with reference to the limited drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

1: Ice slurry production system
11: Tank
12: main circulation pump
13: ice machine
14: recirculation pump

Claims (6)

a tank for storing the working fluid;
a main circulation pump supplying the working fluid stored in the tank to an ice maker;
the ice maker receiving the working fluid and producing ice slurry; and
and a recirculation pump for recirculating a constant flow rate from the outlet of the ice maker to the inlet of the ice maker. According to claim 1,
The ice slurry production system further comprising a control unit for controlling the main circulation pump and the recirculation pump to vary an IPF (Ice Packing Factor) of the ice slurry. 3. The method of claim 2,
The control unit operates the recirculation pump to improve the IPF of the ice slurry to 20% or more. 3. The method of claim 2,
The control unit, in the process of changing the IPF of the ice slurry, first controls the main circulation pump to secure a new flow rate and head, and then operates the recirculation pump. According to claim 1,
The ice maker includes at least one of a sealed single tube ice maker, a sealed multi-tube ice maker, and a sealed disk ice maker. According to claim 1,
The main circulation pump is a type in which a plurality of pumps are connected in parallel, or a pump equipped with an inverter, an ice slurry production system.

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