KR102255372B1 - Portable BOG Heat Exchanging Apparatus - Google Patents

Abstract

The present invention relates to a BOG heat exchanger which can be usefully manufactured and installed, comprising: a cylinder body in which a refrigerant is charged; a cylinder head coupled to an upper part of the cylinder body; a cylinder bottom coupled to a lower part of the cylinder body; a BOG circulation coil disposed in the cylinder body and forming a place where BOG circulates, but in contact with the refrigerant in the cylinder body to keep the BOG cooled; a BOG supply valve coupled to an upper side of the cylinder head and connected to the BOG circulation coil at one side, and supplying BOG to the BOG circulation coil; and a BOG discharge valve coupled to the other upper side of the cylinder head, connected to the BOG circulation coil and the other side, and discharging the BOG circulated through the BOG circulation coil.

Description

Simple manufacturing and installation possible BOG heat exchanger {Portable BOG Heat Exchanging Apparatus}

The present invention relates to a BOG heat exchange device, and more particularly, it is possible to cool or reliquefy BOG more effectively and compactly than in the prior art. In particular, it is possible to downsize and reduce heat loss because there is no need to separately take a refrigerant storage tank as before. It can be minimized and is particularly suitable for non-continuous and intermittent operation, as well as lightening equipment and minimizing the installation area, so it is easy to skid or modularize, and it is possible to easily manufacture and install BOG that can provide more advantages for mobile installation than before. It relates to a heat exchange device.

LNG (Liquefied Natural Gas) is obtained by cooling natural gas to approximately -163℃, and its volume is significantly reduced compared to when it is in the gaseous state, making it suitable for storage and transportation. LNG STORAGE TANK or LNG FUEL that stores such LNG TANK is not only for land vehicles such as LNG FUEL TRUCK, LNG FUEL BUS, but also ships such as LNGC and LNG RV (LNG Regasification Vessel), LNG FSRU (LNG Floating Storage and Regasification Unit), LNG FPSO (LNG Floating Production Storage and Off). It is also installed on offshore structures such as -loading).

On the other hand, LNG storage tanks or LNG fuel tanks are manufactured by being insulated, but since external heat is continuously transmitted to LNG, LNG is vaporized to generate boil-off gas (Boil-Off Gas, hereinafter referred to as "BOG"). .

This BOG increases the pressure in the LNG storage tank or the LNG fuel tank, and accelerates the flow of LNG according to the fluctuation of the vehicle or ship, which may cause structural problems, so it is necessary to suppress the occurrence.

To suppress BOG in the LNG storage tank or LNG fuel tank, BOG is discharged to the outside of the LNG storage tank and incinerated, using BOG as fuel, and evaporation by keeping the internal pressure of the LNG storage tank high. A method of suppressing the generation of gas, a method of discharging BOG to the outside of the LNG storage tank, cooling or re-liquefying it, and then storing it in the LNG storage tank again, cooling the BOG discharged from the fuel tank when charging LNG fuel in the case of land vehicle charging. And storing it in the LNG storage tank at the charging station.

Among the various methods, the latter method, that is, the method of discharging BOG to the outside of the LNG storage tank or LNG fuel tank, or cooling or reliquefaction of the discharged gas is mainly used.In the case of the existing method, due to structural limitations. Miniaturization is disadvantageous, and since a refrigerant storage tank must be taken separately, there is a problem in that heat loss may increase, especially during an operation waiting period during irregular operation.

In addition, the existing method is not suitable for discontinuous and intermittent operation due to its structure, and the installation area may increase due to complex facilities, and thus, skid or modularization is disadvantageous and mobile installation is difficult or impossible.

Korean Intellectual Property Office Application No. 10-2013-0145573 Korean Intellectual Property Office Application No. 10-2014-0037293 Korean Intellectual Property Office Application No. 10-2015-0128111 Korean Intellectual Property Office Application No. 10-2015-0171547

It is an object of the present invention to be able to cool or reliquefy BOG more compactly and effectively than before, and in particular, miniaturization is possible, and heat loss can be minimized since there is no need to take a separate refrigerant storage tank as before, and it is possible to minimize heat loss. In addition to being particularly suitable for operation, it is possible to reduce equipment weight and minimize the installation area, so that it is easy to skid or modularize, and to provide a simple manufacturing and installation BOG heat exchanger capable of providing more advantages than conventional for moving installation.

The simple manufacturing and installation possible BOG heat exchanger according to the present invention comprises: a cylinder body in which a refrigerant is charged; A cylinder head coupled to an upper portion of the cylinder body; A cylinder bottom coupled to a lower portion of the cylinder body; A BOG circulation coil disposed in the cylinder body and forming a place in which the BOG circulates, but contacting the refrigerant in the cylinder body to keep the BOG cooled; A BOG supply valve coupled to an upper side of the cylinder head, connected to the BOG circulation coil at one side, and supplying BOG to the BOG circulation coil; A BOG discharge valve coupled to the other upper side of the cylinder head, connected to the BOG circulation coil at the other side, and discharging the BOG circulated through the BOG circulation coil; An inlet valve provided in the cylinder head and into which a refrigerant or a carrier gas is introduced; An outlet valve provided in the cylinder head adjacent to the inlet valve and through which refrigerant or carrier gas flows out; A valve protection handling spaced apart from and surrounding the BOG supply valve, the BOG discharge valve, the inlet valve, and the outlet valve; A plurality of bridges connected to the valve protection handling and the cylinder head to support the valve protection handling; A refrigerant temperature sensing unit provided in the cylinder body and sensing a temperature of a refrigerant in the cylinder body; A notification display unit provided outside the cylinder body to display a notification; A plurality of heat transfer plates coupled to the BOG circulation coil at regular intervals and inducing the BOG circulating inside the BOG circulation coil to increase a contact area with the refrigerant; A sound-absorbing unit accommodated in the unit receiving groove provided in the bottom of the cylinder to reduce noise; And the BOG circulation coil is arranged in a zigzag manner in the cylinder body such that an area of contact with the refrigerant in the cylinder body is increased, and ends thereof are blocked.

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It may further include a controller that controls the operation of the notification display unit based on the detection signal of the refrigerant temperature detection unit.

According to the present invention, it is possible to cool or re-liquefy BOG more compactly and effectively than before, and in particular, miniaturization is possible, and heat loss can be minimized since there is no need to take a separate refrigerant storage tank as before, and discontinuous and intermittent operation In addition to being particularly suitable for, it is possible to reduce the weight of the equipment and minimize the installation area, so that the skid or modularization is easy, it provides many advantages for moving installation, and has the effect of being able to manufacture and install simply.

1 is a structural diagram of an LNG supply station to which a simple manufacturing and installation possible BOG heat exchanger according to a first embodiment of the present invention is applied.
FIG. 2 is an internal projection structure diagram of the BOG heat exchanger that can be easily manufactured and installed shown in FIG. 1.
3 is a side view of FIG. 2.
4 is a plan view of FIG. 2.
5 is a side view of a BOG heat exchanger that can be easily manufactured and installed according to a second embodiment of the present invention.
6 is a control block diagram of the BOG heat exchanger that can be easily manufactured and installed in FIG. 5.
7 is a partial cross-sectional side view of a BOG heat exchanger that can be easily manufactured and installed according to a third embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments to be described later in detail together with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms.

In the present specification, the present embodiment is provided to complete the disclosure of the present invention, and to completely inform the scope of the present invention to those of ordinary skill in the art to which the present invention pertains. And the invention is only defined by the scope of the claims.

Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques have not been described in detail in order to avoid obscuring interpretation of the present invention.

The same reference numerals refer to the same elements throughout the specification. In addition, terms used in the present specification (referred to) are for explaining embodiments and are not intended to limit the present invention.

In the present specification, the singular form also includes the plural form unless specifically stated in a written phrase. In addition, components and actions (actions) referred to as'comprising (or having)' do not preclude the presence or addition of one or more other components and actions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs.

In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless they are defined.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a structural diagram of an LNG supply station to which a simple manufacturing and installation possible BOG heat exchanger according to a first embodiment of the present invention is applied. FIG. 2 is an internal projection structure diagram of the simple manufacturing and installation possible BOG heat exchanger shown in FIG. 3 is a side view of FIG. 2 and FIG. 4 is a plan view of FIG. 2.

Referring to these drawings, the BOG heat exchanger 110, which can be easily manufactured and installed according to the present embodiment, can cool or reliquefy BOG more effectively and compactly than the conventional one, and in particular, it is possible to downsize, and a refrigerant storage tank (not shown) as before. ) Because it does not need to be taken separately, heat loss can be minimized, and it is particularly suitable for non-continuous and intermittent operation, as well as lightening equipment and minimizing the installation area, making it easy to skid or modular, and has more advantages than before for mobile installation. Can provide.

That is, the BOG heat exchanger 110, which can be easily manufactured and installed according to the present embodiment, is structurally compact, so it is easy to design and manufacture. In particular, if only the length of the BOG circulation coil 115 in which the BOG circulates is manufactured by calculating the amount of heat, the BOG heat exchanger 110 can be easily manufactured and installed, so design and manufacturing are simple and cost can be reduced.

In addition, there is an advantage that it can be used only when necessary because it can be reused by recharging only the refrigerant after being used once or several times depending on the frequency of use or load conditions.

In addition, it is possible to minimize other losses during the waiting period for irregular driving. That is, in the state in which several BOG heat exchangers 110, which can be easily manufactured and installed, are installed and used, the flange connection part may be detached and then recharged again to be used.

In particular, the simple manufacturing and installation BOG heat exchanger 110 according to the present embodiment is particularly suitable for non-continuous and intermittent operation, and it is possible to reduce equipment weight and minimize the installation area, making it easy to skid or modularize, and has many advantages for moving installation. Can provide.

The BOG heat exchanger 110 that can be easily manufactured and installed according to the present embodiment that can provide such an effect can be applied as a single unit component to the LNG supply station 100 of the type shown in FIG. 1.

Before the description of the simple manufacturing and installation possible BOG heat exchanger 110, the LNG supply station 100 will be described. The LNG supply station 100 serves to receive LNG from an LNG storage tank (not shown) and supply the LNG to a place where it is needed.

This LNG supply station 100 is disposed on one side of the frame structure 101 and the frame structure 101, and is connected to the LNG pump 102 for pumping LNG from the LNG storage tank, and the LNG pump 102. It includes a supply piping facility 103 that supplies LNG to a place where it is needed. A vent part 104 is provided on the upper part of the supply piping facility 103.

Accordingly, when the LNG pump 102 is operated, LNG from the LNG storage tank is pumped and supplied to a place where LNG is required.

On the other hand, as described above, the LNG storage tank is manufactured by being insulated, but since external heat is continuously transferred to the LNG, the LNG is vaporized to generate boil-off gas (hereinafter referred to as "BOG").

Since the loss increases as the amount of BOG increases, it must be properly treated.In this embodiment, by applying the BOG heat exchanger 110, which can be easily manufactured and installed, the BOG can be cooled or re-liquefied and reused (LNG return). do.

Accordingly, the LNG supply station 100 is provided with a simple manufacturing and installation BOG heat exchanger 110 on one side of the frame structure 101.

This simple manufacturing and installation possible BOG heat exchanger 110 is coupled to the cylinder body 112 in which the refrigerant is charged, the cylinder head 113 coupled to the upper portion of the cylinder body 112, and the lower portion of the cylinder body 112 It includes a cylinder bottom (114).

The cylinder body 112 at this time is a conventional commercially available cryogenic container. As described above, in the present embodiment, the cylinder body 112 in which the refrigerant is filled, that is, a conventional commercial cryogenic container is used as it is and only some parts are installed, so that design and manufacture are simple and operation is easy.

A BOG circulation coil 115 is provided in the cylinder body 112 to form a place where BOG circulates, but to keep the BOG cooled by contacting the refrigerant in the cylinder body 112. The BOG circulation coil 115 is installed in the cylinder body 112 after its length is calculated and manufactured in advance.

The BOG circulation coil 115 is arranged in a zigzag manner in the cylinder body 112 so that the contact area with the refrigerant in the cylinder body 112 increases, but forms a coil header 115a whose ends are closed. As shown in the figure, when the BOG circulation coil 115 is arranged in a zigzag manner, the contact area with the refrigerant can be increased, thereby increasing the cooling efficiency of the BOG.

A BOG supply valve 119 and a BOG discharge valve 121 are provided so that BOG can be circulated through the BOG circulation coil 115.

The BOG supply valve 119 is coupled to an upper side of the cylinder head 113 and is connected to the BOG circulation coil 115 at one side, and serves to supply BOG to the BOG circulation coil 115. Further, the BOG discharge valve 121 is coupled to the other upper side of the cylinder head 113 and is connected to the BOG circulation coil 115 at the other side, and serves to discharge the BOG circulated through the BOG circulation coil 115.

In addition, in the BOG heat exchanger 110 that can be easily manufactured and installed according to the present embodiment, the cylinder head 113 is provided, and the cylinder is adjacent to the inlet valve 122 through which refrigerant or carrier gas is introduced, and the inlet valve 122 It is provided in the head 113, and is provided with an outlet valve 124 through which refrigerant or carrier gas flows out.

In the vicinity of the BOG supply valve 119, the BOG discharge valve 121, the inlet valve 122, and the outlet valve 124, a valve protection handling 126 spaced apart from and surrounding them is provided.

In addition, a plurality of bridges 127 supporting the valve protection handling 126 are connected to the valve protection handling 126 and the cylinder head 113. Due to these structures, the BOG heat exchanger 110, which can be easily manufactured and installed, can be easily moved.

With this configuration, after installing the BOG heat exchanger 110, which can be easily manufactured and installed as shown in FIG. 1, the pipe is removed so that the BOG is circulated to the BOG circulation coil 115 of the BOG heat exchanger 110, which can be easily manufactured and installed, The BOG circulated is cooled by the refrigerant in the cylinder body 112, and then re-liquefied and returned again.

According to this embodiment, which acts based on the structure as described above, it is possible to cool or reliquefy the BOG more effectively and compactly than the conventional one, and in particular, it is possible to downsize and heat loss because there is no need to take a separate refrigerant storage tank as before. Can be minimized, and is particularly suitable for discontinuous and intermittent operation, as well as lightening equipment and minimizing the installation area, it is easy to skid or modularize, and it is possible to provide more advantages for mobile installation than before.

The effect of the present embodiment will be described in more detail.

First, the simple manufacturing and installation BOG heat exchanger 110 according to the present embodiment is structurally compact, so design and manufacturing are simple and operation is easy. In other words, since it is a form in which only some parts are installed while using a conventional commercially available cryogenic container as it is, design and manufacturing are simple and operation is easy.

In particular, if only the length of the BOG circulation coil 115 in which the BOG circulates is manufactured by calculating the amount of heat, the BOG heat exchanger 110 can be easily manufactured and installed, so design and manufacturing are simple and cost can be reduced.

Second, there is an advantage that it can be used only when necessary because it can be reused by recharging only the refrigerant after being used once or several times depending on the frequency of use or load conditions.

In addition, it is possible to minimize other losses during the waiting period for irregular driving. That is, in the state in which several BOG heat exchangers 110, which can be easily manufactured and installed, are installed and used, the flange connection part may be detached and then recharged again to be used.

In the case of the existing heat exchanger, since the refrigerant storage tank is separately installed outside the heat exchanger to store and use the refrigerant, the equipment cost is high, the installation space is large, and the heat loss of the refrigerant storage tank is inevitably large.

However, in the case of the present embodiment, it is possible to miniaturize and minimize heat loss since it is not necessary to separately take a refrigerant storage tank as before.

In particular, the simple manufacturing and installation BOG heat exchanger 110 according to the present embodiment is particularly suitable for non-continuous and intermittent operation, and it is possible to reduce equipment weight and minimize the installation area, making it easy to skid or modularize, and has many advantages for moving installation. Can provide.

5 is a side view of a BOG heat exchanger that can be easily manufactured and installed according to a second embodiment of the present invention, and FIG. 6 is a control block diagram of the BOG heat exchanger that can be easily manufactured and installed in FIG. 5.

Referring to these drawings, the BOG heat exchanger 210 that can be easily manufactured and installed according to the present embodiment also includes a cylinder body 112 filled with a refrigerant and a cylinder head 113 coupled to an upper portion of the cylinder body 112. ) And a cylinder bottom 114 coupled to a lower portion of the cylinder body 112, and a BOG circulation coil 115 through which BOG circulates is provided in the cylinder body 112. Since the functions and roles of these structures are the same as those of the above-described embodiment, redundant descriptions will be omitted.

On the other hand, in addition to the above configurations, the BOG heat exchanger 210, which can be easily manufactured and installed according to the present embodiment, is further equipped with a refrigerant temperature sensing unit 250, a notification display unit 240, and a controller 260.

The refrigerant temperature sensing unit 250 is provided in the cylinder body 112 and is a kind of sensor that senses the temperature of the refrigerant in the cylinder body 112.

The notification display unit 240 is provided outside the cylinder body 112 and is a means for displaying a notification. The notification display method may be in the form of a lamp or a buzzer. In addition, the notification display unit 240 may be provided in various positions including the handling 126 for valve protection.

The controller 260 controls the operation of the notification display unit 240 based on the detection signal of the refrigerant temperature detection unit 250.

In other words, the controller 260 operates the notification display unit 240 when the refrigerant temperature is higher than the reference value according to the detection signal of the refrigerant temperature sensing unit 250 to allow simple manufacturing and installation. Induce a notification so that it can be replaced.

The controller 260 performing this role may include a central processing unit 261 (CPU), a memory 262 (MEMORY), and a support circuit 263 (SUPPORT CIRCUIT).

The central processing unit 261 may be one of various computer processors that can be industrially applied in order to control the operation of the notification display unit 240 based on the detection signal of the refrigerant temperature detection unit 250 in the present embodiment.

The memory 262 (MEMORY) is connected to the central processing unit 261. The memory 262 may be installed locally or remotely as a computer-readable recording medium, and can be easily used, such as random access memory (RAM), ROM, floppy disk, hard disk, or any digital storage type. It may be at least one or more memories.

The support circuit 263 (SUPPORT CIRCUIT) is coupled with the central processing unit 261 to support the typical operation of the processor. The support circuit 263 may include a cache, a power supply, a clock circuit, an input/output circuit, a subsystem, and the like.

In this embodiment, the controller 260 controls the operation of the notification display unit 240 based on the detection signal of the refrigerant temperature detection unit 250, and such a series of control processes may be stored in the memory 262. Typically software routines may be stored in memory 262. Software routines can also be stored or executed by other central processing units (not shown).

Although the process according to the present invention has been described as being executed by a software routine, it is also possible that at least some of the processes of the present invention are performed by hardware.

As such, the processes of the present invention may be implemented by software executed on a computer system, or by hardware such as an integrated circuit, or by a combination of software and hardware.

Even if this embodiment is applied, the BOG can be cooled or re-liquefied more effectively and compactly than the conventional one, and in particular, it is possible to downsize and minimize heat loss since there is no need to take a separate refrigerant storage tank as before, and discontinuous and intermittent operation In addition to being particularly suitable for, it is possible to reduce the weight of equipment and minimize the installation area, so that the skid or modularization is easy, and it can provide many advantages for moving installation.

7 is a partial cross-sectional side view of a BOG heat exchanger that can be easily manufactured and installed according to a third embodiment of the present invention.

Referring to this drawing, the BOG heat exchanger 310 which can be easily manufactured and installed according to the present embodiment also includes a cylinder body 112 filled with a refrigerant and a cylinder head 113 coupled to an upper portion of the cylinder body 112. ) And a cylinder bottom 314 coupled to a lower portion of the cylinder body 112, and a BOG circulation coil 115 through which BOG circulates is provided in the cylinder body 112. Since the functions and roles of these structures are the same as those of the above-described embodiment, redundant descriptions will be omitted.

Meanwhile, in the case of the present embodiment, a plurality of heat transfer plates 316 are coupled to the BOG circulation coil 115. The heat transfer plate 316 may be made of the same material as the BOG circulation coil 115, and may be provided by welding to the BOG circulation coil 115.

Like the BOG circulation coil 115, the heat transfer plate 316 may contribute to inducing the BOG circulating into the BOG circulation coil 115 to increase the contact area with the refrigerant.

Even if this embodiment is applied, the BOG can be cooled or re-liquefied more effectively and compactly than the conventional one, and in particular, it is possible to downsize and minimize heat loss since there is no need to take a separate refrigerant storage tank as before, and discontinuous and intermittent operation In addition to being particularly suitable for, it is possible to reduce the weight of equipment and minimize the installation area, so that the skid or modularization is easy, and it can provide many advantages for moving installation.

On the other hand, in the case of this embodiment, the sound absorption unit 380 is provided in the cylinder bottom 314. The sound absorption unit 380 can be installed by separating the cylinder bottom 314 from the base 315 forming the lower portion of the cylinder bottom 314 and then receiving it in the unit receiving groove 314a in the cylinder bottom 314. have. Therefore, it is also possible to replace.

When the sound absorbing unit 380 is provided as in the present embodiment, there is an advantage in that the noise that may be generated during the cooling or re-liquefaction of the BOG can be somewhat reduced.

In addition, in the BOG heat exchanger 310 that can be easily manufactured and installed according to the present embodiment, a plurality of wheels 316 and a plurality of height adjustment stoppers 317 are provided under the base 315.

Due to the plurality of wheels 316, it is advantageous to move the BOG heat exchanger 310, which can be easily manufactured and installed with a rather heavy weight. In addition, it may be of great help in fixing the position of the BOG heat exchanger 310, which can be easily manufactured and installed, to the system of FIG. 1 due to the plurality of stoppers 317 for height adjustment.

Even if this embodiment is applied, the BOG can be cooled or re-liquefied more effectively and compactly than the conventional one, and in particular, it is possible to downsize and minimize heat loss since there is no need to take a separate refrigerant storage tank as before, and discontinuous and intermittent operation In addition to being particularly suitable for, it is possible to reduce the weight of equipment and minimize the installation area, so that the skid or modularization is easy, and it can provide many advantages for moving installation.

As described above, the present invention is not limited to the described embodiments, and it is obvious to those of ordinary skill in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, it should be said that such modifications or variations belong to the claims of the present invention.

100: LNG supply station 101: LNG pump
103: supply piping equipment 110: BOG heat exchanger
112: cylinder body 113: cylinder head
114: cylinder bottom 115: BOG circulation coil
115a: coil header 117: bundle of gas inflow and outflow
118: pressure gauge 119: BOG supply valve
121: BOG discharge valve 122: inlet valve
124: outflow valve 126: handling for valve protection
127: Bridge

Claims (5)

A cylinder body in which the refrigerant is charged;
A cylinder head coupled to an upper portion of the cylinder body;
A cylinder bottom coupled to a lower portion of the cylinder body;
A BOG circulation coil disposed in the cylinder body and forming a place in which the BOG circulates, but contacting the refrigerant in the cylinder body to keep the BOG cooled;
A BOG supply valve coupled to an upper side of the cylinder head, connected to the BOG circulation coil at one side, and supplying BOG to the BOG circulation coil;
A BOG discharge valve coupled to the other upper side of the cylinder head, connected to the BOG circulation coil at the other side, and discharging the BOG circulated through the BOG circulation coil;
An inlet valve provided in the cylinder head and into which a refrigerant or a carrier gas is introduced;
An outlet valve provided in the cylinder head adjacent to the inlet valve and through which refrigerant or carrier gas flows out;
A valve protection handling spaced apart from and surrounding the BOG supply valve, the BOG discharge valve, the inlet valve, and the outlet valve;
A plurality of bridges connected to the valve protection handling and the cylinder head to support the valve protection handling;
A refrigerant temperature sensing unit provided in the cylinder body and sensing a temperature of a refrigerant in the cylinder body;
A notification display unit provided outside the cylinder body to display a notification;
A plurality of heat transfer plates coupled to the BOG circulation coil at regular intervals and inducing the BOG circulating inside the BOG circulation coil to increase a contact area with the refrigerant;
A sound-absorbing unit accommodated in the unit receiving groove provided in the bottom of the cylinder to reduce noise; And
The BOG circulation coil is arranged in a zigzag manner in the cylinder body so as to increase the contact area with the refrigerant in the cylinder body, but forms a coil header whose ends are blocked.
delete delete delete The method of claim 1,
And a controller configured to control an operation of the notification display unit based on a detection signal of the refrigerant temperature detection unit.

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