KR102388814B1 - Cooling system to cool multiple auxiliary refrigerant using LNG cold heat - Google Patents

Abstract

In accordance with an embodiment of the present invention, a cooling system for cooling a plurality of auxiliary refrigerants by using LNG cold heat includes: a first main heat exchanger causing a heat exchange between a main refrigerant and liquefied gas, which is discharged from a liquefied gas storage tank by a fixed amount preset per unit time, so as to cool a main cold storage; a first main refrigerant pipe connected with the main cold storage, and in which the main refrigerant passing through the first main heat exchanger flows; N auxiliary heat exchangers causing a sequential heat exchange between N auxiliary refrigerants and the main refrigerant so as to cool N (N is a natural number which is no less than 2) auxiliary cold storages; and N auxiliary refrigerant pipes connected with the N auxiliary cold storages respectively, and in which the N auxiliary refrigerants flow respectively. Therefore, the present invention is capable of reducing costs for cooling facilities and costs for cooling operation.

Description

A cooling system for cooling a plurality of auxiliary refrigerants using LNG cold heat

The present invention relates to a cooling system for cooling a plurality of auxiliary refrigerants using LNG cold heat, and more particularly, it is possible to reduce cooling facility cost and cooling operation cost, as well as improve the convenience of maintenance of cooling facility. related to the cooling system.

In general, a cooling system is a system to prevent overheating, and is also used to cool a refrigeration warehouse. A frozen warehouse is a warehouse that stores agricultural products, fish, meat, etc., and a cooling system facility for cooling agricultural products, fish, meat, etc. to a certain temperature or less is essential.

Such a cooling system can cool the refrigerated warehouse by using the cooling heat of the refrigerant that has undergone heat exchange with the liquefied gas. That is, the refrigerant receives cooling heat from the liquefied gas through the heat exchanger and is cooled, and then passes through the freezing warehouse to supply the cooling heat to the freezing warehouse. Accordingly, the freezing warehouse can be maintained at the set temperature. For example, LNG gas may be used as the liquefied gas.

Korean Patent Registration No. 10-1885695 has been proposed as a prior art document for cooling a refrigerant by using the heat of vaporization of liquefied gas.

On the other hand, the refrigerant retains a certain amount of cooling heat even after supplying cooling heat to the refrigerating warehouse. You can do it. However, since the conventionally proposed technique does not use the cooling heat of the refrigerant remaining after the refrigerant exchanged with liquefied gas supplies the cooling heat to the refrigeration warehouse, efficient operation is difficult.

The present invention has been devised to solve the above-described problems, and provides a cooling system for cooling a plurality of auxiliary refrigerants using LNG cold heat, which can promote efficient operation and further reduce cooling facility costs and cooling operating costs. It is intended to provide

The present invention can implement a cooling system that cools a plurality of auxiliary refrigerants using LNG cooling heat.

In the cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, the main refrigerant exchanges heat with the liquefied gas, which is discharged from the liquefied gas storage tank in a predetermined amount per unit time, so that the main freezing warehouse is cooled. The first main heat exchanger that makes this happen, the main refrigerant pipe connected to the main freezing warehouse and through which the main refrigerant passing through the first main heat exchanger flows, N auxiliary refrigerants so that N (N is a natural number of 2 or more) auxiliary freezing warehouse is cooled and N auxiliary heat exchangers for sequentially exchanging heat with the main refrigerant, and N auxiliary refrigerant pipes each connected to the N auxiliary refrigeration warehouses and through which the N auxiliary refrigerants flow, respectively.

The cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention as described above can cool a plurality of refrigerating warehouses using a single refrigerant, thereby promoting efficient operation and further cooling Equipment cost and cooling operation cost can be reduced.

In addition, in the cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, a certain amount of liquefied gas is discharged from the liquefied gas storage tank even if the external environment, season, operating conditions, etc. change, In operating the cooling system, predictability can be secured and stable liquefied gas can be supplied to demand.

1 is a block diagram of a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
2 is a block diagram of valves, a control unit, a sensor, and a determination unit in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
3 is a flowchart of a method of increasing the cooling heat supplied to the main refrigerating warehouse in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
4 is a flowchart of a method of maintaining the temperature of the main refrigerant that has passed through the second main heat exchanger in the cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
5 is a flowchart illustrating a method of increasing cooling heat supplied to a first auxiliary refrigerant in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
6 is a flowchart of a method of increasing cooling heat supplied to a second auxiliary refrigerant in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.
7 is a flowchart of a method of increasing the cooling heat supplied to the first auxiliary freezing warehouse in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

The terms used in the embodiments are selected as currently widely used general terms as possible while considering functions in the present invention, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, and the like. In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than the name of a simple term.

Expressions such as “comprises” or “may include” that may be used in various embodiments of the present invention indicate the existence of a corresponding disclosed function, operation, or component, and may include one or more additional functions, operations, or Components, etc. are not limited. In addition, in various embodiments of the present invention, terms such as “comprise” or “have” are intended to designate that a feature, number, step, action, component, part, or combination thereof described in the specification is present, It should be understood that this does not preclude the possibility of addition or existence of one or more other features or numbers, steps, operations, components, parts, or combinations thereof.

When a component is referred to as being “connected” to another component, the component may be directly connected to the other component, but a new component is formed between the component and the other component. It should be understood that there may be On the other hand, when an element is referred to as being “directly connected” or “directly connected” to another element, it will be understood that no new element exists between the element and the other element. should be able to

Terms used in various embodiments of the present invention are only used to describe a specific embodiment, and are not intended to limit various embodiments of the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which various embodiments of the present invention pertain.

Hereinafter, with reference to the accompanying drawings, the embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement them. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention is used to cool a refrigeration warehouse for storing logistics, etc. using liquefied gas. In the following embodiment, the liquefied gas will be described on the basis of LNG (liquefied natural gas), but as long as it can cool the refrigeration warehouse, other modifications may be included.

1 is a block diagram of a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention. The temperature shown in FIG. 1 does not mean a specific temperature, but should be understood as an example.

The cooling system (1) for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention discharges a predetermined amount per unit time from the liquefied gas storage tank (10) so that the main freezing warehouse (100) is cooled. The first main heat exchanger (3) that allows heat exchange between liquefied gas and the main refrigerant, the main refrigerant pipe (2) connected to the main freezing warehouse 100 and through which the main refrigerant passing through the first main heat exchanger (3) flows; N auxiliary heat exchangers that sequentially exchange heat with N auxiliary refrigerants and main refrigerant so that N (N is a natural number of 2 or more) auxiliary freezing warehouses are cooled, and N auxiliary heat exchangers are connected to each, and N auxiliary freezing warehouses It includes N sub-refrigerant pipes through which the sub-refrigerant flows, respectively.

The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention cools the main freezing warehouse 100 using the main refrigerant heat exchanged with liquefied gas, and then removes the residual cooling heat. It is possible to sequentially cool the first auxiliary refrigerant and the second auxiliary refrigerant by using the own main refrigerant again. The first auxiliary refrigerant and the second auxiliary refrigerant having heat exchange with the main refrigerant may respectively freeze the first auxiliary freezing warehouse 200 and the second auxiliary freezing warehouse 300 .

Accordingly, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can cool the plurality of refrigerating warehouses 100, 200, 300 using one main refrigerant. Therefore, it is possible to achieve efficient operation of the cooling system. Furthermore, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention is separately for cooling the first auxiliary freezing warehouse 200 and the second auxiliary freezing warehouse 300 . In comparison with the prior art, it is possible to reduce the cooling equipment since the installation of a mechanical refrigerator of the refrigeration system is not necessarily required. Accordingly, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can reduce cooling facility cost and cooling operation cost, as well as improve the convenience of maintenance of the cooling facility. can be improved

Hereinafter, when N is 2, that is, an embodiment of the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cold heat including two auxiliary heat exchangers and two auxiliary refrigerant pipes will be described. However, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention may be implemented when N is 3 or more.

Referring to FIG. 1 , a cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention includes a main refrigerant pipe 2 , a first main heat exchanger 3 , and a first auxiliary refrigerant. It may include a pipe (4), a first auxiliary heat exchanger (5), a second auxiliary refrigerant pipe (6), and a second auxiliary heat exchanger (7). However, the components of the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to the embodiment of the present invention are not limited thereto, and other components according to the embodiment may be added, or at least one Components may be omitted.

Hereinafter, the main refrigerant pipe (2), the first main heat exchanger (3), the first auxiliary refrigerant pipe (4), the first auxiliary heat exchanger (5), the second auxiliary refrigerant pipe (6), and the second auxiliary heat exchanger With reference to the accompanying drawings for (7) will be described in detail.

Referring to FIG. 1 , the main refrigerant pipe 2 is a pipe through which the main refrigerant flows. In this embodiment, a pipe, a flow path, or a line should be understood to mean a pipe that guides the flow of a fluid.

The main refrigerant is a fluid that exchanges heat with liquefied gas. As the main refrigerant exchanges heat with the liquefied gas in the first main heat exchanger 3 , the main refrigerant may receive cooling heat from the liquefied gas. Accordingly, the temperature of the main refrigerant can be reduced. The main refrigerant may be used to maintain the temperature of the main freezing warehouse (100). The main refrigerant may be R-407a.

The liquefied gas that transfers cooling heat to the main refrigerant may be discharged in a predetermined amount from the liquefied gas storage tank 10 and flow along the liquefied gas transfer pipe 11 . The liquefied gas may be discharged from the liquefied gas storage tank 10 at -153°C. A liquefied gas control valve 12 for controlling the flow rate of the liquefied gas may be installed in the liquefied gas transfer pipe 11 .

Conventionally, when the external environment, season, operating conditions, etc. change, the amount of cooling heat supplied to the refrigeration warehouses 100, 200, 300 changes, so the amount of liquefied gas discharged from the liquefied gas storage tank 10 can be changed. there was only However, according to the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, even if the external environment, season, operation situation, etc. are changed, a constant from the liquefied gas storage tank 10 Since a positive amount of liquefied gas is discharged, predictability can be secured in operating the cooling system and stable liquefied gas can be supplied to demanding parties.

As shown in FIG. 1, the main refrigerant pipe 2 includes a 1-1 pipe 2a, a 1-2 pipe 2b, a first bypass line 2c, and a 1-3 pipe 2d. , second bypass line 2e, 1-4 pipe 2f, third bypass line 2g, 1-5 pipe 2h, fourth bypass line 2i, 1-5 It may include a pipe 2h, and a 1-6th pipe 2j. As the main refrigerant sequentially flows through the lower components of the main refrigerant pipe (2), heat exchange with the liquefied gas, the first auxiliary refrigerant, and the second auxiliary refrigerant can be made in the heat exchangers (3, 5, 7).

A main refrigerant tank 400 may be installed in the main refrigerant pipe (2). The main refrigerant tank 400 may be used to store the main refrigerant and replenish the main refrigerant in the main refrigerant pipe (2). The main refrigerant tank 400 may be disposed between the 1-1 pipe (2a) and the 1-2th pipe (2b). Although not shown, a flow meter may be installed in the main refrigerant pipe (2).

Referring to FIG. 1 , the first main heat exchanger 3 allows heat exchange between the liquefied gas and the main refrigerant. The main refrigerant supplied with cooling heat from the liquefied gas in the first main heat exchanger 3 may supply cooling heat to the main freezing warehouse 100 to cool the main freezing warehouse 100 . For example, the main refrigerant may cool the main freezing warehouse 100 to a temperature of -80°C or higher and -60°C or lower.

The first main heat exchanger 3 may be connected to each of the liquefied gas transfer pipe 11 and the main refrigerant pipe 2 . Specifically, the first main heat exchanger 3 may be disposed between the 1-1 pipe (2a) and the 1-6th pipe (2j). The temperature of the main refrigerant passing through the first main heat exchanger 3 may be reduced from -62°C to -95°C. The liquefied gas passing through the first main heat exchanger 3 may be increased in temperature from -153°C to -67°C.

The entire amount of the liquefied gas supplied to the first main heat exchanger (3) can be maintained at -95°C or lower at all times by supplying cooling heat to the main refrigerant. Therefore, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can be implemented to enable rapid cooling and heat supply according to the instantaneous refrigeration load change of the main freezing warehouse 100 . there is.

According to an embodiment of the present invention, the liquefied gas and the main refrigerant having a predetermined constant temperature and a predetermined predetermined amount may be supplied to the first main heat exchanger (3). The material of the first main heat exchanger 3 is generally a metal material such as stainless or aluminum, and when the flow rate and temperature of the liquefied gas fluctuate, the point at which it is vaporized in the heat exchanger fluctuates, which is heat exchange The temperature inside the machine may continuously fluctuate. Such a situation continuously gives stress such as expansion and contraction inside the first main heat exchanger 3, and when such a situation occurs for a long time, there is a risk that the shape of the heat exchanger may be deformed or cracked.

In addition, LNG is composed of components such as methane, ethane, propane, butane, and these components have different vaporization temperature points. This may be discharged from the first main heat exchanger (3) in a two-phase coexistence of liquid and gas according to the temperature of the LNG discharged from the first main heat exchanger (3). At this time, when a low flow rate of LNG is supplied to the first main heat exchanger 3 due to a reduction in the refrigeration load of the main freezing warehouse 100 , the LNG flow rate inside the first main heat exchanger 3 slows down, so ethane and propane with a high vaporization point , butane, etc. cannot be discharged out of the first main heat exchanger 3 in a liquid state and are stagnated inside the first main heat exchanger 3, thereby reducing the fluidity of the fluid and at the same time reducing the heat exchange efficiency between the main refrigerant and the LNG. there is. Moreover, there may be a case where the first main heat exchanger 3 is damaged due to icing occurring inside the first main heat exchanger 3 .

In order to solve this problem, the fluidity of the fluid is increased by narrowing the internal flow path width of the first main heat exchanger 3, or by installing a drain facility in the lower part of the first main heat exchanger 3, There is a method of vaporizing and discharging LNG, but such a method increases the pressure loss inside the first main heat exchanger 3, increases the installation cost of the first main heat exchanger 3, and the first main heat exchanger ( 3) There is a difficulty in maintenance.

Therefore, according to the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, a constant temperature and a constant amount of liquefied gas and a constant temperature and a constant amount of the main refrigerant are the first main heat Since each can be supplied to the exchanger (3), the possibility of damage or damage to the first main heat exchanger (3) can be reduced. Accordingly, the period of use of the first main heat exchanger 3 may be increased. In addition, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can improve the heat exchange efficiency between the main refrigerant and the liquefied gas, and the first main heat exchanger (3) can reduce operating costs.

Referring to FIG. 1 , the first auxiliary refrigerant pipe 4 is a pipe through which the first auxiliary refrigerant flows. The first auxiliary refrigerant is a fluid that heat exchanges with the main refrigerant. As the first auxiliary refrigerant exchanges heat with the main refrigerant in the first auxiliary heat exchanger (5), the first auxiliary refrigerant may receive cooling heat from the main refrigerant. Accordingly, the temperature of the first auxiliary refrigerant may be reduced. The first auxiliary refrigerant may be used to maintain the temperature of the first auxiliary freezing warehouse 200 at a temperature lower than that of the main freezing warehouse 100 . The first auxiliary refrigerant may be R-507a. In a modified embodiment, the first auxiliary refrigerant may be the same as the main refrigerant.

A first auxiliary refrigerant tank 500 may be installed in the first auxiliary refrigerant pipe 4 . The first auxiliary refrigerant tank 500 may be used to store the first auxiliary refrigerant, and to replenish the first auxiliary refrigerant in the first auxiliary refrigerant pipe (4).

Referring to FIG. 1 , the first auxiliary heat exchanger 5 allows heat exchange between the main refrigerant and the first auxiliary refrigerant. The first auxiliary refrigerant supplied with cooling heat from the main refrigerant in the first auxiliary heat exchanger 5 may supply cooling heat to the first auxiliary freezing warehouse 200 to cool the first auxiliary freezing warehouse 200 . For example, the first auxiliary refrigerant may cool the first auxiliary freezing warehouse 200 to a temperature of -30°C.

The first auxiliary heat exchanger 5 may be connected to each of the main refrigerant pipe 2 and the first auxiliary refrigerant pipe 4 . Specifically, the first auxiliary heat exchanger 5 may be disposed between the 1-3 pipes 2d and the 1-4 pipes 2f. The temperature of the first auxiliary refrigerant passing through the first auxiliary heat exchanger 5 may be reduced from -35°C to -45°C. The temperature of the main refrigerant passing through the first auxiliary heat exchanger 5 may be increased from -80°C to -70°C.

According to an embodiment of the present invention, the main refrigerant and the first auxiliary refrigerant having a predetermined constant temperature and a predetermined predetermined amount may be respectively supplied to the first auxiliary heat exchanger (5).

In various operating environments of the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, a failure occurs in the first auxiliary heat exchanger 5, so that the main refrigerant and the first auxiliary The heat exchange between the refrigerants is stopped or the amount of cooling heat supplied to the main freezing warehouse 100 is excessively generated, so that the first auxiliary refrigerant cannot receive cooling heat from the main refrigerant. In this case, in order to maintain the temperature of the first auxiliary freezer 200, the cooling system 1 for cooling the plurality of auxiliary refrigerants using LNG cooling heat according to the embodiment of the present invention is the first auxiliary freezer 5a. may include

The first auxiliary refrigerator 5a may be installed in the first auxiliary flow path 4a branched from the first auxiliary refrigerant pipe 4 . The first sub-refrigerant 5a may compress and condense the first sub-refrigerant to cool the first sub-refrigerant. Accordingly, the cooled first auxiliary refrigerant may be supplied to the first auxiliary freezing warehouse 200 to cool the first auxiliary freezing warehouse 200 . The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention is a first auxiliary refrigerator 5a Through this, since the temperature of the first auxiliary freezing warehouse 200 can be constantly maintained, the ability to respond to various operating environments can be improved.

Referring to FIG. 1 , the second auxiliary refrigerant pipe 6 is a pipe through which the second auxiliary refrigerant flows. The second auxiliary refrigerant is a fluid that heat exchanges with the main refrigerant. As the second auxiliary refrigerant exchanges heat with the main refrigerant in the second auxiliary heat exchanger (7), the second auxiliary refrigerant may receive cooling heat from the main refrigerant. Accordingly, the temperature of the second auxiliary refrigerant may be reduced. The second auxiliary refrigerant may be used to maintain the temperature of the second auxiliary freezing warehouse 300 at a lower temperature than the first auxiliary freezing warehouse 200 . The second auxiliary refrigerant may be R-507a. In a modified embodiment, the second auxiliary refrigerant may be the same as the main refrigerant.

According to an embodiment of the present invention, the main refrigerant, the first auxiliary refrigerant, and the second auxiliary refrigerant may flow through each pipe while maintained in a liquid state. Therefore, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention uses only liquid sensible heat without phase change of the refrigerants in the refrigerating warehouses 100, 200, 300. It can be implemented to maintain the temperature.

A second auxiliary refrigerant tank 600 may be installed in the second auxiliary refrigerant pipe 6 . The second auxiliary refrigerant tank 600 may be used to store the second auxiliary refrigerant, and to replenish the second auxiliary refrigerant in the second auxiliary refrigerant pipe (6).

Referring to FIG. 1 , the second auxiliary heat exchanger 7 allows heat exchange between the main refrigerant and the second auxiliary refrigerant. The second auxiliary refrigerant supplied with cooling heat from the main refrigerant in the second auxiliary heat exchanger 7 may supply cooling heat to the second auxiliary freezing warehouse 300 to cool the second auxiliary freezing warehouse 300 . For example, the second auxiliary refrigerant may cool the second auxiliary freezing warehouse 300 to a temperature of 2°C.

The second auxiliary heat exchanger 7 may be connected to each of the main refrigerant pipe 2 and the second auxiliary refrigerant pipe 6 . The second auxiliary heat exchanger 7 may be disposed between the 1-4th pipe 2f and the 1-5th pipe 2h. The second auxiliary refrigerant passing through the second auxiliary heat exchanger (7) may be reduced in temperature from -10°C to -20°C. The temperature of the main refrigerant passing through the second auxiliary heat exchanger 7 may be increased from -70°C to -62°C.

The temperature of the second refrigerant cooled from the main refrigerant through the second auxiliary heat exchanger (7) may be higher than the temperature of the first auxiliary refrigerant cooled from the main refrigerant through the first auxiliary heat exchanger (5). That is, the temperature of the plurality of auxiliary refrigerants sequentially heat-exchanged with the main refrigerant may be gradually increased. Accordingly, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can set different temperatures between auxiliary refrigerants, and further set different cooling temperatures between auxiliary freezing warehouses. can Accordingly, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention can implement various operating environments using one main refrigerant.

According to an embodiment of the present invention, the main refrigerant and the second auxiliary refrigerant having a predetermined constant temperature and a predetermined constant amount may be respectively supplied to the second auxiliary heat exchanger (7).

In various operating environments of the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention, a failure occurs in the second auxiliary heat exchanger 7, so that the main refrigerant and the second auxiliary The heat exchange between the refrigerants is stopped or the amount of cooling heat supplied to the main freezing warehouse 100 is excessively generated, so that the second auxiliary refrigerant does not receive cooling heat from the main refrigerant. In this case, in order to maintain the temperature of the second auxiliary freezer 300, the cooling system 1 for cooling the plurality of auxiliary refrigerants using the LNG cooling heat according to the embodiment of the present invention includes the second auxiliary freezer 7a. may include

The second auxiliary refrigerator 7a may be installed in the second auxiliary flow path 6a branched from the second auxiliary refrigerant pipe 6 . The second sub-refrigerant 7a may compress and condense the second sub-refrigerant to cool the second sub-refrigerant. Accordingly, the cooled second auxiliary refrigerant may be supplied to the second auxiliary freezing warehouse 300 to cool the second auxiliary freezing warehouse 300 . The cooling system 1 for cooling a plurality of auxiliary refrigerants by using LNG cooling heat according to an embodiment of the present invention operates the second auxiliary refrigerator 7a even if a situation occurs where the second auxiliary refrigerant does not receive cooling heat from the main refrigerant. Since it is possible to maintain a constant temperature of the second auxiliary freezing warehouse 300 through, it is possible to improve the ability to respond to various operating environments.

Referring to FIG. 1 , the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention may further include a second main heat exchanger 8 .

The second main heat exchanger (8) is disposed between the second auxiliary heat exchanger (7) and the first main heat exchanger (3) along the direction in which the main refrigerant flows in the main refrigerant pipe (2), so that the first main heat exchanger ( 3) It is possible to increase the temperature of the main refrigerant supplied. The second main heat exchanger 8 may be disposed between the 1-5th pipe 2h and the 1-6th pipe 2j. Accordingly, the temperature of the main refrigerant is increased by the second main heat exchanger (8) while flowing through the 1-5 pipe (2h) and the 1-6th pipe (2j), and is supplied to the first main heat exchanger (3) again. can Hot water may be supplied to the second main heat exchanger (8).

The second main heat exchanger (8) can always maintain a constant temperature of the main refrigerant supplied to the first main heat exchanger (3) by raising the temperature of the main refrigerant. If the main refrigerant supplied to the first main heat exchanger (3) and the temperature are continuously changed, the amount of liquefied gas discharged from the liquefied gas storage tank (10) in order to cool the main refrigerant is inevitably changed. In this case, predictability in operating the cooling system 1 may be lowered, and a problem may occur that a stable liquefied gas cannot be supplied to a demanding party.

The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention always maintains the temperature of the main refrigerant supplied to the first main heat exchanger 3 through the second main heat exchanger 8 . Since it can be kept constant, it is possible to stably supply liquefied gas to the consumers.

Referring to FIG. 1 , the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention may further include a liquefied gas heat exchanger 9 .

The liquefied gas heat exchanger 9 is installed in the liquefied gas transfer pipe 11 . The liquefied gas heat exchanger 9 is disposed past the first main heat exchanger 3 along the direction in which the liquefied gas flows, and may increase the temperature of the liquefied gas that has passed through the first main heat exchanger 3 . The liquefied gas is raised from -67°C to 5°C by the liquefied gas heat exchanger (9), and can be supplied to the demanding place.

2 is a block diagram of valves, a control unit, a sensor, and a determination unit in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

1 and 2 , a cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention includes a first valve 20 , a second valve 30 , and a second 3 may further include a valve (40).

The first valve 20 is installed in the main refrigerant pipe (2). The first valve 20 may control the flow or flow of the main refrigerant flowing through the main refrigerant pipe (2). The first valve 20 is a 1-1 valve 21 , a 1-2 valve 22 , a 1-3 valve 23 , a 1-4 valve 24 , and a 1-5 valve 25 . ), a 1-6 valve 26 , a 1-7 valve 27 , and a 1-8 valve 28 may be included.

The 1-1 valve 21 may control the flow rate of the main refrigerant supplied to the main freezing warehouse 100 . When the 1-1 valve 21 is opened, the main refrigerant may be supplied to the main freezing warehouse 100 to cool the main freezing warehouse 100 . Accordingly, the temperature of the main freezing warehouse 100 can be kept constant.

The 1-2 valve 22 may be installed in the first bypass line 2c bypassing the main freezing warehouse 100 . The 1-2 valve 22 may control the flow rate of the main refrigerant passing through the first bypass line 2c. The first bypass line 2c may be branched from the 1-2-th pipe 2b at the first branch point BP1 and installed. When the 1-2 valve 22 is opened and the 1-1 valve 21 is closed, the main refrigerant may not be supplied to the main freezing warehouse 100 . The first bypass line 2c may be installed to be connected to the 1-3 pipe 2d at the first junction JP1.

The 1-3 valve 23 may control the flow rate of the main refrigerant supplied to the first auxiliary heat exchanger 5 . When the 1-3 valve 23 is opened, the main refrigerant may be supplied to the first auxiliary heat exchanger 5 to transfer cooling heat to the first auxiliary refrigerant.

The 1-4 valves 24 may be installed in the second bypass line 2e bypassing the first auxiliary heat exchanger 5 . The 1-4 valve 24 may adjust the flow rate of the main refrigerant passing through the second bypass line 2e. The second bypass line 2e may be branched from the 1-3 pipe 2d at the second branch point BP2 and installed. When the 1-4 valve 24 is opened and the 1-3 valve 23 is closed, the main refrigerant may not be supplied to the first auxiliary heat exchanger 5 . The second bypass line 2e may be installed to be connected to the 1-4 pipes 2f at the second junction JP2.

The 1-5 valve 25 may control the flow rate of the main refrigerant supplied to the second auxiliary heat exchanger 7 . When the 1-5 valve 25 is opened, the main refrigerant may be supplied to the second auxiliary heat exchanger 7 to transfer cooling heat to the second auxiliary refrigerant.

The 1-6 valve 26 may be installed in the third bypass line 2g bypassing the second auxiliary heat exchanger 7 . The 1-6 valve 26 may adjust the flow rate of the main refrigerant passing through the third bypass line 2g. The third bypass line 2g may be branched from the 1-4 pipes 2f at the third branch point BP3 and installed. When the 1-6 valve 26 is opened and the 1-5 valve 25 is closed, the main refrigerant may not be supplied to the second auxiliary heat exchanger 7 . The third bypass line 2g may be installed to be connected to the first-5 pipes 2h at the third junction JP3.

The 1-7 valve 27 can adjust the flow rate of the main refrigerant supplied to the second main heat exchanger (8). When the 1-7 valve 27 is opened, the main refrigerant may be supplied to the second main heat exchanger 8 to increase the temperature.

The 1-8 valve 28 may be installed in the fourth bypass line 2i bypassing the second main heat exchanger 8 . The 1-8 valve 28 may adjust the flow rate of the main refrigerant passing through the fourth bypass line 2i. The fourth bypass line 2i may be installed to be branched from the first-5 pipes 2h at the fourth branch point BP4. When the 1-8 valve 28 is opened and the 1-7 valve 27 is closed, the main refrigerant may not be supplied to the second main heat exchanger 8 . The fourth bypass line 2i may be installed to be connected to the first-6 pipes 2j at the fourth junction JP4.

1 and 2 , the second valve 30 is installed in the first auxiliary refrigerant pipe 4 . The second valve 30 may control the flow rate or flow of the first auxiliary refrigerant flowing through the first auxiliary refrigerant pipe 4 or the first auxiliary flow path 4a. The second valve 30 may include a 2-1 valve 31 and a 2-2 valve 32 .

The 2-1 valve 31 is installed in the first auxiliary refrigerant pipe 4 to adjust the flow rate of the first auxiliary refrigerant supplied to the first auxiliary freezing warehouse 200 . When the 2-1 valve 31 is opened, the first auxiliary refrigerant may be supplied to the first auxiliary freezing warehouse 200 to cool the first auxiliary freezing warehouse 200 . Accordingly, the temperature of the first auxiliary freezing warehouse 200 can be kept constant.

The 2-2 valve 32 may be installed in the first auxiliary flow path 4a to control the flow rate of the first auxiliary refrigerant supplied to the first auxiliary refrigerator 5a. When the 2-2 valve 32 is opened and the 2-1 valve 31 is closed, the first auxiliary refrigerant may be supplied to the first auxiliary refrigerator 5a to be cooled.

1 and 2 , the third valve 40 is installed in the second auxiliary refrigerant pipe 6 . The third valve 40 may control the flow rate and flow of the second auxiliary refrigerant flowing through the second auxiliary refrigerant pipe 6 or the second auxiliary flow path 6a. The third valve 40 may include a 3-1 valve 41 and a 3-2 valve 42 .

The 3-1 valve 41 is installed in the second auxiliary refrigerant pipe 6 to adjust the flow rate of the second auxiliary refrigerant supplied to the second auxiliary freezing warehouse 300 . When the 3-1 valve 41 is opened, the second auxiliary refrigerant may be supplied to the second auxiliary freezing warehouse 300 to cool the second auxiliary freezing warehouse 300 . Accordingly, the temperature of the second auxiliary freezing warehouse 300 can be kept constant.

The 3-2 valve 42 is installed in the second auxiliary flow path 6a to control the flow rate of the second auxiliary refrigerant supplied to the second auxiliary refrigerator 7a. When the 3-2 valve 42 is opened and the 3-1 valve 41 is closed, the second auxiliary refrigerant may be supplied to the second auxiliary refrigerator 7a to be cooled.

Referring to FIG. 2 , the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention further includes a control unit 50 , a temperature sensor 60 , and a determination unit 70 . may include

The control unit 50 controls overall operations of components included in the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention. The controller 50 may control operations of the first valve 20 , the second valve 30 , and the third valve 40 .

The control unit 50 includes at least one processor. The processor may be implemented as an array of a plurality of logic gates, or may be implemented as a combination of a general-purpose microprocessor and a memory in which a program executable in the microprocessor is stored. In addition, it can be understood by those skilled in the art that the present embodiment may be implemented in other types of hardware.

The control unit 50 may include a first control module 51 , a second control module 52 , and a third control module 53 .

The first control module 51 may control the operation of the first valve 20 . The first control module 51 includes a 1-1 valve 21, a 1-2 valve 22, a 1-3 valve 23, a 1-4 valve 24, and a 1-5 valve ( 25), the 1-6th valve 26 , the 1-7th valve 27 , and the 1-8th valve 28 may each control the operation.

The second control module 52 may control the operation of the second valve 30 . The second control module 52 may control the respective operations of the 2-1 valve 31 and the 2-2 valve 32 .

The third control module 53 may control the operation of the third valve 40 . The third control module 53 may control the respective operations of the 3-1 valve 41 and the 3-2 valve 42 .

Referring to FIG. 2 , the temperature sensor 60 senses the temperatures of the refrigerating warehouses 100 , 200 , 300 or the main refrigerant, the first auxiliary refrigerant, and the second auxiliary refrigerant. The temperature sensed by the temperature sensor 60 may be provided to the control unit 50 or the determination unit 70 .

The temperature sensor 60 may include a first temperature sensor 61 , a second temperature sensor 62 , and a third temperature sensor 63 .

The first temperature sensor 61 senses the temperature of the main refrigerant flowing in the main freezing warehouse 100 or the main refrigerant pipe (2). The first temperature sensor 61 may provide information about the sensed temperatures of the main freezing warehouse 100 and the main refrigerant to the first control module 51 and the determination unit 70 . For example, the first temperature sensor 61 may sense whether the main freezing warehouse 100 exceeds a preset first temperature. The first temperature may be -60°C.

The second temperature sensor 62 senses the temperature of the first auxiliary refrigerant flowing in the first auxiliary freezing warehouse 200 or the first auxiliary refrigerant pipe 4 . The second temperature sensor 62 transmits information about the sensed temperature of the first auxiliary freezing warehouse 200 and the first auxiliary refrigerant to the first control module 51 , the second control module 52 , and the determination unit 70 . ) can be provided. For example, the second temperature sensor 62 may sense whether the first auxiliary refrigerant exceeds a preset second temperature. The second temperature may be -45°C.

The third temperature sensor 63 senses the temperature of the second auxiliary refrigerant flowing in the second auxiliary freezing warehouse 300 or the second auxiliary refrigerant pipe 6 . The third temperature sensor 63 transmits information about the sensed temperature of the second auxiliary freezing warehouse 300 and the second auxiliary refrigerant to the first control module 51 , the third control module 53 , and the determination unit 70 . ) can be provided. For example, the third temperature sensor 63 may sense whether the second auxiliary refrigerant exceeds a third preset temperature. The third temperature may be -20°C.

Referring to FIG. 2 , the determination unit 70 determines that when the amount of heat to be removed from the main freezing warehouse 100 is excessively generated, when a failure occurs in the heat exchangers 3 , 5 , and 7 , the liquefied gas is It is determined whether the heat exchange between the main refrigerant and the first auxiliary refrigerant and the heat exchange between the main refrigerant and the second auxiliary refrigerant according to the case where it is not discharged from the liquefied gas storage tank 10 are stopped. The information determined by the determination unit 70 may be provided to the control unit 50 .

The determination unit 70 may include a first determination module 71 and a second determination module 72 .

The first determination module 71 receives information about the temperature of the first auxiliary refrigerant that has passed through the first auxiliary heat exchanger 5 from the second temperature sensor 62, and exchanges heat between the main refrigerant and the first auxiliary refrigerant. It can be judged that this is interrupted. In addition, the first determination module 71 may receive information about the temperature of the main freezing warehouse 100 from the first temperature sensor 61 and determine that the temperature of the main freezing warehouse is equal to or greater than a preset first temperature. The information determined by the first determination module 71 may be provided to the second control module 52 .

The second determination module 72 receives information about the temperature of the second auxiliary refrigerant that has passed through the second auxiliary heat exchanger 7 from the third temperature sensor 63, and exchanges heat between the main refrigerant and the second auxiliary refrigerant. It can be judged that this is interrupted. In addition, the second determination module 72 may receive information about the temperature of the main freezing warehouse 100 from the first temperature sensor 61 and determine that the temperature of the main freezing warehouse is equal to or greater than a preset first temperature. The information determined by the second determination module 72 may be provided to the third control module 53 .

Hereinafter, various embodiments in which the control unit 50 controls the valves 20, 30, 40 using information sensed by the temperature sensor 60 and information determined by the determination unit 70 will be described with reference to the accompanying drawings. Let's look at them sequentially.

First, a method in which the first control module 51 controls the first valve 20 using information about the temperature sensed by the first temperature sensor 61 will be described with reference to FIGS. 3 and 4 . .

3 is a flowchart of a method of increasing the cooling heat supplied to the main refrigerating warehouse in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

First, the temperature of the main freezing warehouse 100 is sensed (S11). This step (S11) may be performed by the first temperature sensor 61. The first temperature sensor 61 may directly sense the temperature of the main freezing warehouse 100 , and may sense the temperature of the main refrigerant supplied to the main freezing warehouse 100 .

Next, information about the temperature of the main freezing warehouse 100 sensed by the first temperature sensor 61 is provided to the first control module 51 .

Next, the first control module 51 determines whether the temperature of the main freezing warehouse 100 exceeds a first preset temperature. For example, the first control module 51 may determine whether the temperature of the main freezing warehouse 100 exceeds -60 ℃. In this case, it is necessary to increase the amount of cooling heat supplied to the main freezing warehouse 100 .

Next, when the temperature of the main freezing warehouse 100 exceeds the first preset temperature, the amount of cooling heat supplied to the main freezing warehouse 100 is increased (S12). The step (S12) of increasing the amount of cooling heat supplied to the main freezing warehouse 100 may be performed by the first control module 51 . The step (S12) of increasing the amount of cooling heat supplied to the main freezing warehouse 100 is the step of increasing the flow rate of the main refrigerant passing through the 1-1 valve 21 (S121), and the 1-2 valve 22 ) may include a step (S122) of reducing the flow rate of the main refrigerant passing through.

The first control module 51 may increase the flow rate of the main refrigerant passing through the 1-1 valve 21 by opening the 1-1 valve 21 , and the 1-2 valve 22 . By closing the , the flow rate of the main refrigerant passing through the 1-2 valve 22 can be reduced. Accordingly, the temperature of the main freezing warehouse 100 can be maintained in a state of -80 ℃ or more and -60 ℃ or less. Steps S121 and S122 may be performed in parallel or sequentially.

By increasing the amount of cooling heat supplied to the main freezing warehouse 100 through the above method, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cold heat according to the embodiment of the present invention is the main freezing warehouse ( 100) can be maintained.

4 is a flowchart of a method of maintaining the temperature of the main refrigerant that has passed through the second main heat exchanger in the cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

First, the temperature of the main refrigerant supplied to the second main heat exchanger (8) is sensed (S21). This step (S21) may be performed by the first temperature sensor 61. The first temperature sensor 61 may measure the temperature of the main refrigerant flowing through the first-5 pipes 2h.

Next, information on the temperature of the main refrigerant supplied to the second main heat exchanger 8 sensed by the first temperature sensor 61 is provided to the first control module 51 .

Next, the first control module 51 determines whether the temperature of the main refrigerant supplied to the second main heat exchanger (8) is different from the preset supply temperature. For example, the first control module 51 may determine whether the temperature of the main freezing warehouse 100 is less than -62 ℃. In this case, it is necessary to maintain the temperature of the main refrigerant supplied to the first main heat exchanger (3) at -62 ℃.

Next, when the temperature of the main refrigerant supplied to the second main heat exchanger (8) is less than the preset supply temperature, the flow rate of the main refrigerant supplied to the second main heat exchanger (8) is increased (S22). This step ( S22 ) may be performed by the first control module 51 . The step (S22) of increasing the flow rate of the main refrigerant supplied to the second main heat exchanger (8) is the step (S221) of increasing the flow rate of the main refrigerant passing through the 1-7 valves 27 (S221), and 1-8 It may include a step (S222) of reducing the flow rate of the main refrigerant passing through the valve (28).

The first control module 51 may increase the flow rate of the main refrigerant passing through the 1-7 valve 27 by opening the 1-7 valve 27 , and the 1-8 valve 28 . It is possible to reduce the flow rate of the main refrigerant passing through the 1-8 valve (28) by closing the. Accordingly, the temperature of the main refrigerant that has passed through the second main heat exchanger (8) may be increased to -62°C and supplied to the first main heat exchanger (3). Steps S221 and S222 may be performed in parallel or sequentially.

A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention by maintaining the temperature of the main refrigerant supplied to the first main heat exchanger 3 through the method as described above at a preset supply temperature (1) can stably supply the liquefied gas passing through the first main heat exchanger (3) to the customer.

Second, a method in which the first control module 51 controls the first valve 20 using information about the temperature sensed by the second temperature sensor 62 will be described with reference to FIG. 5 .

5 is a flowchart illustrating a method of increasing cooling heat supplied to a first auxiliary refrigerant in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

First, the temperature of the first auxiliary refrigerant flowing through the first auxiliary refrigerant pipe 4 is sensed (S31). This step S31 may be performed by the second temperature sensor 62 . On the other hand, this step (S31) may be replaced with a step of directly measuring the temperature of the first auxiliary freezing warehouse (200).

Next, information on the temperature of the first auxiliary refrigerant sensed by the second temperature sensor 62 is provided to the first control module 51 .

Next, the first control module 51 determines whether the temperature of the first auxiliary refrigerant exceeds a preset second temperature. For example, the first control module 51 may determine whether the temperature of the first auxiliary refrigerant exceeds -45 ℃. In this case, it is necessary to reduce the temperature of the first auxiliary refrigerant.

On the other hand, when the step (S31) of detecting the temperature of the first auxiliary refrigerant is replaced with the step of directly measuring the temperature of the first auxiliary freezing warehouse 200, the first control module 51 is the first auxiliary freezing warehouse ( 200), it can be determined whether the temperature exceeds -30°C.

Next, when the temperature of the first auxiliary refrigerant exceeds the second preset temperature, the flow rate of the main refrigerant supplied to the first auxiliary heat exchanger 5 is increased (S32). This step ( S32 ) may be performed by the first control module 51 . The step (S32) of increasing the flow rate of the main refrigerant supplied to the first auxiliary heat exchanger (5) is a step (S321) of increasing the flow rate of the main refrigerant passing through the 1-3 valve (23), and the first- 4 may include a step (S322) of reducing the flow rate of the main refrigerant passing through the valve (24).

The first control module 51 may increase the flow rate of the main refrigerant passing through the 1-3 valves 23 by opening the 1-3 valves 23, and the 1-4 valves 24 By closing the , the flow rate of the main refrigerant passing through the 1-4 valves 24 can be reduced. Accordingly, since a large amount of the main refrigerant passes through the first auxiliary heat exchanger (5), the first auxiliary refrigerant receives a large amount of cooling heat from the main refrigerant and is cooled to -45 ° C. ) can be supplied. In this case, the first auxiliary freezing warehouse 200 may be maintained at -30 ℃ or less. Steps S321 and S322 may be performed in parallel or sequentially.

The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention only controls the first valve 20, and the first It may be implemented to maintain the temperature of the auxiliary refrigerant and the temperature of the first auxiliary freezing warehouse 200 . Therefore, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention provides the temperature and the first auxiliary refrigerant without installing a separate facility in the first auxiliary refrigerant pipe 4 . Since it is possible to maintain the temperature of the auxiliary freezing warehouse 200, it is possible to reduce the equipment cost.

Meanwhile, although not shown, when it is necessary to supply a large amount of cooling heat to the first auxiliary freezing warehouse 200, the second control module 52 directly opens the 2-1 valve 31, and the first auxiliary The amount of cooling heat supplied to the freezing warehouse 200 may be increased.

Third, a method in which the first control module 51 controls the first valve 20 using information about the temperature sensed by the third temperature sensor 63 will be described with reference to FIG. 6 .

6 is a flowchart of a method of increasing cooling heat supplied to a second auxiliary refrigerant in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

First, the temperature of the second auxiliary refrigerant flowing through the second auxiliary refrigerant pipe 6 is sensed (S41). This step (S41) may be performed by the third temperature sensor (63). On the other hand, this step (S41) may be replaced with a step of directly measuring the temperature of the second auxiliary freezing warehouse (300).

Next, information on the temperature of the second auxiliary refrigerant sensed by the third temperature sensor 63 is provided to the first control module 51 .

Next, the first control module 51 determines whether the temperature of the second auxiliary refrigerant exceeds a third preset temperature. For example, the first control module 51 may determine whether the temperature of the second auxiliary refrigerant exceeds -20 °C. In this case, it is necessary to reduce the temperature of the second auxiliary refrigerant.

On the other hand, when the step (S41) of detecting the temperature of the second auxiliary refrigerant is replaced with the step of directly measuring the temperature of the second auxiliary freezing warehouse 300, the first control module 51 is the second auxiliary freezing warehouse ( 300) it can be determined whether the temperature exceeds 2 ℃.

Next, when the temperature of the second auxiliary refrigerant exceeds the third preset temperature, the flow rate of the main refrigerant supplied to the second auxiliary heat exchanger 7 is increased (S42). This step ( S42 ) may be performed by the first control module 51 . The step (S42) of increasing the flow rate of the main refrigerant supplied to the second auxiliary heat exchanger (7) is a step (S421) of increasing the flow rate of the main refrigerant passing through the 1 - 5 valves 25 (S421), and 1 - 6 It may include a step (S422) of reducing the flow rate of the main refrigerant passing through the valve (26).

The first control module 51 can increase the flow rate of the main refrigerant passing through the 1-5 valve 25 by opening the 1-5 valve 25 , and the 1-6 valve 26 . By closing , the flow rate of the main refrigerant passing through the 1-6 valve 26 can be reduced. Accordingly, since a large amount of the main refrigerant passes through the second auxiliary heat exchanger (7), the second auxiliary refrigerant receives a large amount of cooling heat from the main refrigerant and is cooled to -20 ° C. can be supplied with In this case, the second auxiliary freezing warehouse 300 may be maintained at 2 ℃. Steps S421 and S422 may be performed in parallel or sequentially.

The cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention only controls the first valve 20, and the second auxiliary refrigerant pipe 6 flows through the second auxiliary refrigerant pipe 6 . It may be implemented to maintain the temperature of the auxiliary refrigerant and the temperature of the second auxiliary freezing warehouse 300 . Therefore, the cooling system 1 for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention provides the temperature and the second auxiliary refrigerant without installing a separate facility in the second auxiliary refrigerant pipe 6 . Since it is possible to maintain the temperature of the auxiliary freezing warehouse 300, it is possible to reduce the equipment cost.

Fourth, a method in which the second control module 52 controls the second valve 30 using the information determined by the first determination module 71 will be described with reference to FIG. 7 .

7 is a flowchart of a method of increasing the cooling heat supplied to the first auxiliary freezing warehouse in a cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat according to an embodiment of the present invention.

First, it is determined whether the heat exchange between the main refrigerant and the first auxiliary refrigerant is stopped (S51). This step S51 may be performed by the first determination module 71 . The first determination module 71 determines whether the temperature of the first auxiliary refrigerant that has passed through the first auxiliary heat exchanger 5 exceeds the second preset temperature, so that the heat exchange between the main refrigerant and the first auxiliary refrigerant is It can be determined whether or not it has been discontinued. In this case, the first determination module 71 may determine whether heat exchange between the main refrigerant and the first auxiliary refrigerant is stopped using the information on the temperature of the first auxiliary refrigerant from the second temperature sensor 62 . .

On the other hand, the step (S51) of determining whether the heat exchange between the main refrigerant and the first auxiliary refrigerant is stopped may be replaced with the step of determining whether the temperature of the main freezing warehouse 100 exceeds a preset first temperature. there is. In this case, the first determination module 71 determines whether the heat exchange between the main refrigerant and the first auxiliary refrigerant is stopped using the information about the temperature of the main freezing warehouse 100 from the first temperature sensor 61. can

Next, the information determined by the first determination module 71 is provided to the second control module 52 .

Next, when the heat exchange between the main refrigerant and the first auxiliary refrigerant is stopped or the temperature of the main freezing warehouse 100 exceeds the first preset temperature, the first auxiliary refrigerant that has passed through the first auxiliary heat exchanger (5) It is supplied to the first auxiliary freezer (5a) (S52). This step ( S52 ) may be performed by the second control module ( 52 ). The step of supplying the first auxiliary refrigerant that has passed through the first auxiliary heat exchanger (5) to the first auxiliary refrigerator (5a) (S52) reduces the flow rate of the first auxiliary refrigerant passing through the 2-1 valve (31). and increasing the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 .

The second control module 52 may reduce the flow rate of the first auxiliary refrigerant passing through the 2-1 valve 31 as the 2-1 valve 31 is closed, and the 2-2 valve 32 ), the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 may be increased. Accordingly, the first auxiliary refrigerant may be supplied to the first auxiliary refrigerator (5a). The first sub-refrigerant supplied to the first sub-cooler 5a may be compressed, condensed and cooled to -45°C. Decreasing the flow rate of the first auxiliary refrigerant passing through the 2-1 valve 31 and increasing the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 may be performed in parallel, , may be performed sequentially.

Next, the first auxiliary refrigerant compressed and condensed in the first auxiliary freezer 5a is supplied to the first auxiliary freezing warehouse 200 (S53). This step S53 may be performed by the second control module 52 . The step (S53) of supplying the first auxiliary refrigerant compressed and condensed in the first auxiliary refrigerator (5a) to the first auxiliary freezing warehouse (200) (S53) is the flow rate of the first auxiliary refrigerant passing through the 2-1 valve (31) and decreasing the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 .

The second control module 52 may increase the flow rate of the first auxiliary refrigerant passing through the 2-1 valve 31 as the 2-1 valve 31 is opened, and the 2-2 valve 32 ), it is possible to reduce the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 as it is closed. Accordingly, the first auxiliary refrigerant cooled to -45 ℃ may be supplied to the first auxiliary freezing warehouse (200). Accordingly, the first auxiliary freezing warehouse 200 may be maintained at -30 ℃. The step of increasing the flow rate of the first auxiliary refrigerant passing through the 2-1 valve 31 and the step of decreasing the flow rate of the first auxiliary refrigerant passing through the 2-2 valve 32 may be performed in parallel, and , may be performed sequentially.

As described above, when the amount of heat to be removed from the main freezing warehouse 100 is excessively generated, when a failure occurs in the heat exchangers 3 , 5 , 7 , liquefied gas is discharged from the liquefied gas storage tank 10 . Even if the situation does not occur, the first auxiliary refrigerant cooled through the first auxiliary freezer (5a) without directly receiving cooling heat from the main refrigerant can be directly supplied to the first auxiliary freezing warehouse (200). there is. That is, the cooling system 1 for cooling the plurality of auxiliary refrigerants using the LNG cooling heat according to the embodiment of the present invention is separate from the control of the first valve 20 by the first control module 51, the second Since the control module 52 may cool the first auxiliary refrigerant by adjusting the second valve 30 , it is possible to further improve the ability to respond to various operating conditions.

On the other hand, the embodiment in which the third control module 53 controls the third valve 40 to supply the second auxiliary refrigerant to the second auxiliary refrigerator 7a using the information determined by the second determination module 72 is , since the implementation is almost identical to the embodiment of FIG. 7 , a detailed description thereof will be omitted.

A person of ordinary skill in the art related to this embodiment will understand that it can be implemented in a modified form without departing from the essential characteristics of the above description. Therefore, the disclosed methods are to be considered in an illustrative rather than a restrictive sense. The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

1: A cooling system that cools a plurality of auxiliary refrigerants using LNG cooling heat
2: main refrigerant pipe 3: first main heat exchanger
4: first auxiliary refrigerant pipe 5: first auxiliary heat exchanger
6: Second auxiliary refrigerant pipe 7: Second auxiliary heat exchanger
8: second main heat exchanger 9: liquefied gas heat exchanger
10: liquefied gas storage tank 11: liquefied gas transfer pipe
12: liquefied gas control valve 20: first valve
30: second valve 40: third valve
50: control unit 60: temperature sensor
70: judgment unit 100: main frozen warehouse
200: first auxiliary freezing warehouse 300: second auxiliary freezing warehouse

Claims (12)

a first main heat exchanger (3) for allowing heat exchange between the liquefied gas and the main refrigerant discharged in a predetermined amount per unit time from the liquefied gas storage tank (10) so that the main freezing warehouse (100) is cooled;
a main refrigerant pipe (2) connected to the main freezing warehouse (100) and through which the main refrigerant passing through the first main heat exchanger (3) flows;
a first auxiliary refrigerant pipe (4) through which a first auxiliary refrigerant that primarily exchanges heat with the main refrigerant flows and is connected to a first auxiliary refrigerant warehouse (200);
a second auxiliary refrigerant pipe (6) through which a second auxiliary refrigerant secondarily heat-exchanged with the main refrigerant flows and to which a second auxiliary freezing warehouse (300) is connected;
a first auxiliary heat exchanger (5) for allowing heat exchange between the main refrigerant and the first auxiliary refrigerant so that the first auxiliary freezing warehouse (200) connected to the first auxiliary refrigerant pipe (4) is cooled;
a second auxiliary heat exchanger (7) for allowing heat exchange between the main refrigerant and the second auxiliary refrigerant so that the second auxiliary freezing warehouse (300) connected to the second auxiliary refrigerant pipe (6) is cooled; and
It is disposed between the second auxiliary heat exchanger (7) and the first main heat exchanger (3) along the direction in which the main refrigerant flows in the main refrigerant pipe (2), and to the first main heat exchanger (3) A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that it comprises; a second main heat exchanger (8) for increasing the temperature of the supplied main refrigerant. delete The method of claim 1,
The temperature of the second auxiliary refrigerant cooled from the main refrigerant through the second auxiliary heat exchanger (7) is the temperature of the first auxiliary refrigerant cooled from the main refrigerant through the first auxiliary heat exchanger (5) A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that higher. delete The method of claim 1,
a first valve (20) installed in the main refrigerant pipe (2) and controlling the flow rate of the main refrigerant flowing through the main refrigerant pipe (2); and
A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that it further comprises a first control module (51) for controlling the first valve (20). 6. The method of claim 5,
The first valve 20 includes a 1-1 valve 21 for controlling the flow rate of the main refrigerant supplied to the main freezing warehouse 100 , and a first bypassing the main freezing warehouse 100 . and a 1-2 valve 22 installed in the bypass line 2c to control the flow rate of the main refrigerant passing through the first bypass line 2c,
When the temperature of the main freezing warehouse 100 exceeds a first preset temperature, the first control module 51 increases the flow rate of the main refrigerant passing through the 1-1 valve 21 and A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that the first valve (20) is controlled to reduce the flow rate of the main refrigerant passing through the 1-2 valves (22). 6. The method of claim 5,
The first valve 20 includes a 1-3 valve 23 for regulating the flow rate of the main refrigerant supplied to the first auxiliary heat exchanger 5, and bypassing the first auxiliary heat exchanger 5 It is installed in the second bypass line (2e) and includes a 1-4 valve (24) for controlling the flow rate of the main refrigerant passing through the second bypass line (2e),
When the temperature of the first auxiliary refrigerant exceeds the second preset temperature, the first control module 51 increases the flow rate of the main refrigerant passing through the 1-3 valves 23 and 1 - 4 A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that the first valve (20) is controlled to reduce the flow rate of the main refrigerant passing through the valves (24). 6. The method of claim 5,
The first valve 20 includes a 1-5 valve 25 for regulating the flow rate of the main refrigerant supplied to the second auxiliary heat exchanger 7 and bypassing the second auxiliary heat exchanger 7 . and a 1-6 valve 26 installed in the third bypass line 2g to control the flow rate of the main refrigerant passing through the third bypass line 2g,
When the temperature of the second auxiliary refrigerant exceeds a third preset temperature, the first control module 51 increases the flow rate of the main refrigerant passing through the 1-5 valves 25 and 1-6 A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that the first valve (20) is controlled to reduce the flow rate of the main refrigerant passing through valves (26). 6. The method of claim 5,
It is disposed between the second auxiliary heat exchanger (7) and the first main heat exchanger (3) along the direction in which the main refrigerant flows in the main refrigerant pipe (2), and to the first main heat exchanger (3) Further comprising; a second main heat exchanger (8) for increasing the temperature of the supplied main refrigerant;
The first valve 20 includes a 1-7 valve 27 for controlling the flow rate of the main refrigerant supplied to the second main heat exchanger 8, and bypassing the second main heat exchanger 8 and a 1-8 valve (28) installed in the fourth bypass line (2i) to control the flow rate of the main refrigerant passing through the fourth bypass line (2i),
When the temperature of the main refrigerant supplied to the second main heat exchanger 8 is less than a preset supply temperature, the first control module 51 controls the flow rate of the main refrigerant passing through the 1-7 valve 27 . A plurality of auxiliary refrigerants using LNG cooling heat, characterized in that by controlling the first valve 20 to increase the temperature and reduce the flow rate of the main refrigerant passing through the 1-8 valves 28 Cooling cooling system. The method of claim 1,
a second valve (30) installed in the first auxiliary refrigerant pipe (4) to control the flow rate of the first auxiliary refrigerant supplied to the first auxiliary freezing warehouse (200); and
Cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that it further comprises; a second control module (52) for controlling the second valve (30) according to the temperature of the first auxiliary freezing warehouse (200) letting cooling system. The method of claim 1,
a first auxiliary freezer (5a) for compressing and condensing the first auxiliary refrigerant and then cooling the first auxiliary refrigerant warehouse (200) using the first auxiliary refrigerant; and
When the temperature of the main freezing warehouse 100 exceeds a preset first temperature or the temperature of the first auxiliary refrigerant exceeds a preset second temperature, the first secondary heat exchanger (5) A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that it further comprises a second control module (52) for controlling the supply of one auxiliary refrigerant to the first auxiliary refrigerator (5a). The method of claim 1,
A liquefied gas heat exchanger (9) disposed past the first main heat exchanger (3) along the direction in which the liquefied gas flows, and raising the temperature of the liquefied gas passing through the first main heat exchanger (3); A cooling system for cooling a plurality of auxiliary refrigerants using LNG cooling heat, characterized in that it further comprises.

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