WO2021106984A1

WO2021106984A1 - Cold recovery system, ship including cold recovery system, and cold recovery method

Info

Publication number: WO2021106984A1
Application number: PCT/JP2020/043956
Authority: WO
Inventors: 亮 ▲高▼田; 晃川波; 英司齋藤
Original assignee: 三菱重工マリンマシナリ株式会社
Priority date: 2019-11-26
Filing date: 2020-11-26
Publication date: 2021-06-03
Also published as: EP4035985A1; JP7288842B2; CN114651148B; EP4035985A4; KR20220062651A; JP2021085443A; CN114651148A

Abstract

This cold recovery system is installed in a ship having a liquefied gas storage device that stores a liquid liquefied gas, the system comprising: a working fluid circulation line that causes a working fluid having a lower freezing point than water to circulate therethrough; a cold recovery device that includes a turbine driven by the working fluid; a first heat exchanger that exchanges heat between the liquefied gas and the working fluid; an intermediate heat medium circulation line that causes an intermediate heat medium having a lower freezing point than water to circulate therethrough; a second heat exchanger that is provided on the downstream side of the working fluid circulation line with respect to the first heat exchanger, and exchanges heat between the working fluid and the intermediate heat medium; and a third heat exchanger that exchanges heat between the intermediate heat medium and heated water introduced from the outside of the cold recovery system.

Description

Cold heat recovery system, ships equipped with cold heat recovery system, and cold heat recovery method

The present disclosure relates to a cold heat recovery system installed on a ship having a liquefied gas storage device configured to store liquid liquefied gas, a ship equipped with the cold heat recovery system, and a cold heat recovery method by the cold heat recovery system.

The land LNG (liquefied natural gas) base accepts and stores liquefied natural gas transported by LNG carriers. Then, when supplying liquefied natural gas to a supply destination such as city gas or a thermal power plant, the liquefied natural gas is warmed with seawater or the like and returned to gas. When vaporizing liquefied natural gas, cryogenic power generation may be performed in which cold energy is recovered as electric power instead of being discarded in seawater (for example, Patent Document 1).

It is difficult to establish a land-based LNG terminal corresponding to each supply destination of liquefied natural gas because it costs money to secure land. Therefore, a ship equipped with an LNG storage facility for storing liquefied natural gas and a regassing facility for regassing liquefied natural gas is moored at sea, and the liquefied natural gas regassed by the ship is used in the pipeline. It may be sent to a supply destination on land or a power gauge (floating power plant) at sea.

Since ships are less expandable than onshore equipment, it is important to reduce the size of the cryogenic power generation system, especially the heat exchanger, in order to install the cryogenic power generation equipment. Examples of the small heat exchanger include a printed circuit heat exchanger (PCHE) and a plate heat exchanger.

JP-A-2017-180323

If the temperature of the other heat exchange target is lower than the freezing point of one heat exchange target (for example, seawater), one heat exchange target solidifies during heat exchange in the heat exchanger, and the solidified heat exchange target heats up. It may adhere to the surface of the exchanger and block the heat exchanger. Compared with a large heat exchanger (for example, a shell tube type heat exchanger), a small heat exchanger has a higher risk of blockage of the heat exchanger, and therefore has a problem in reliability.

In view of the above circumstances, an object of at least one embodiment of the present disclosure is to suppress blockage of the heat exchanger due to solidification of the heat medium, and reliability of the cold heat recovery system when using a small heat exchanger. The purpose is to provide a cold heat recovery system capable of improving the properties.

The cold heat recovery system according to the present disclosure is
A cold heat recovery system installed on a ship that has a liquefied gas storage device configured to store liquid liquefied gas.
A working fluid circulation line configured to circulate a working fluid with a lower freezing point than water,
A cold heat recovery device including a turbine configured to be driven by the working fluid flowing through the working fluid circulation line.
A first heat exchanger configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line.
An intermediate heat medium circulation line configured to circulate an intermediate heat medium having a lower freezing point than water,
A second heat exchanger provided on the downstream side of the working fluid circulation line with respect to the first heat exchanger, the working fluid flowing through the working fluid circulation line and the intermediate heat medium circulation line flowing through the working fluid circulation line. A second heat exchanger configured to exchange heat with the intermediate heat medium,
A third heat exchanger configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line and the heated water introduced from the outside of the cold heat recovery system is provided.

The ship according to the present disclosure is equipped with the above-mentioned cold heat recovery system.

The cold heat recovery method according to the present disclosure is
A cold heat recovery method using a cold heat recovery system installed on a ship having a liquefied gas storage device configured to store liquid liquefied gas.
The cold heat recovery system
A working fluid circulation line configured to circulate a working fluid with a lower freezing point than water,
A cold heat recovery device including a turbine configured to be driven by the working fluid flowing through the working fluid circulation line.
A first heat exchanger configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line.
An intermediate heat medium circulation line configured to circulate an intermediate heat medium having a lower freezing point than water,
A second heat exchanger provided on the downstream side of the working fluid circulation line with respect to the first heat exchanger, the working fluid flowing through the working fluid circulation line and the intermediate heat medium circulation line flowing through the working fluid circulation line. A second heat exchanger configured to exchange heat with the intermediate heat medium,
A third heat exchanger configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line and the heated water introduced from the outside of the cold heat recovery system is provided.
The cold heat recovery method is
A first heat exchange step in which heat is exchanged between the liquefied gas and the working fluid by the first heat exchanger.
A second heat exchange step in which heat is exchanged between the working fluid that has undergone heat exchange with the liquefied gas in the first heat exchange step by the second heat exchanger and the intermediate heat medium.
The third heat exchanger includes an intermediate heat medium that exchanges heat with the working fluid in the second heat exchange step, and a third heat exchange step that exchanges heat between the heated water. ..

According to at least one embodiment of the present disclosure, blockage of the heat exchanger due to solidification of the heat medium can be suppressed, and the reliability of the cold heat recovery system when using a small heat exchanger can be improved. A cold heat recovery system is provided.

FIG. 5 is a schematic configuration diagram schematically showing a configuration of a ship provided with a cold heat recovery system according to an embodiment of the present disclosure. It is a schematic block diagram which shows schematic the whole structure of the cold heat recovery system which concerns on 1st Embodiment of this disclosure. It is a schematic block diagram which shows schematic the whole structure of the cold heat recovery system which concerns on the 2nd Embodiment of this disclosure. It is a schematic block diagram which shows schematic the whole structure of the cold heat recovery system which concerns on 3rd Embodiment of this disclosure. It is a schematic block diagram which shows schematic the whole structure of the cold heat recovery system which concerns on a comparative example. It is explanatory drawing for demonstrating an example of the heat exchanger in one Embodiment of this disclosure. It is a flow chart of the cold heat recovery method which concerns on one Embodiment of this disclosure.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely explanatory examples. Absent.
For example, expressions that represent relative or absolute arrangements such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" are exact. Not only does it represent such an arrangement, but it also represents a state of relative displacement with tolerances or angles and distances to the extent that the same function can be obtained.
For example, expressions such as "same", "equal", and "homogeneous" that indicate that things are in the same state not only represent exactly the same state, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, an expression representing a shape such as a quadrangular shape or a cylindrical shape not only represents a shape such as a quadrangular shape or a cylindrical shape in a geometrically strict sense, but also an uneven portion or chamfering within a range in which the same effect can be obtained. The shape including the part and the like shall also be represented.
On the other hand, the expression "includes", "includes", or "has" one component is not an exclusive expression that excludes the existence of another component.
The same reference numerals may be given to the same configurations, and the description thereof may be omitted.

(Vessels equipped with a cold heat recovery system)
FIG. 1 is a schematic configuration diagram schematically showing a configuration of a ship including a cold heat recovery system according to an embodiment of the present disclosure.
The cold heat recovery system 2 according to some embodiments is installed on the ship 1 as shown in FIG. As shown in FIG. 1, the ship 1 includes a hull 10 and a cold heat recovery system 2 mounted on the hull 10. In the illustrated embodiment, the ship 1 further includes a liquefied gas storage device (for example, a liquefied gas tank) 11 mounted on the hull 10. The liquefied gas storage device 11 is configured to store liquefied gas (for example, liquefied natural gas).

In the illustrated embodiment, the engine room 15 is formed inside the hull 10. The engine room 15 is equipped with an engine (for example, a marine diesel engine) 16 for imparting propulsive force to the ship 1. In this case, by driving the engine 16, the ship 1 can be moved from the liquefied gas supply source to the vicinity of the liquefied gas supply destination.

(Cold heat recovery system)
FIG. 2 is a schematic configuration diagram schematically showing the overall configuration of the cold heat recovery system according to the first embodiment of the present disclosure. FIG. 3 is a schematic configuration diagram schematically showing the overall configuration of the cold heat recovery system according to the second embodiment of the present disclosure. FIG. 4 is a schematic configuration diagram schematically showing the overall configuration of the cold heat recovery system according to the third embodiment of the present disclosure.

As shown in FIGS. 2 to 4, the cold heat recovery system 2 according to some embodiments includes a liquefied gas supply line 3, a working fluid circulation line 4, a cold heat recovery device 41, and an intermediate heat medium circulation line 6. A heated water supply line 7, a first heat exchanger 51, a second heat exchanger 52, and a third heat exchanger 53 are provided. Each of the liquefied gas supply line 3, the working fluid circulation line 4, the intermediate heat medium circulation line 6, and the heated water supply line 7 includes a flow path through which the fluid flows.

The liquefied gas supply line 3 is configured to send liquefied gas from the liquefied gas storage device 11. The working fluid circulation line 4 is configured to circulate a working fluid having a freezing point lower than that of water. Hereinafter, liquefied natural gas (LNG) will be described as a specific example of liquefied gas, and propane will be used as a specific example of working fluid. However, the present disclosure is applicable to liquefied gas other than liquefied natural gas. It is also applicable when a heat medium other than propane is used as the working fluid.

In the illustrated embodiment, the cold heat recovery system 2 includes a liquefied gas pump 31 provided in the liquefied gas supply line 3 and a working fluid circulation pump 44 provided in the working fluid circulation line 4. One end side 301 of the liquefied gas supply line 3 is connected to the liquefied gas storage device 11, and the other end side 302 is connected to the liquefied gas equipment 12 provided outside the cold heat recovery system 2. Examples of the device 12 for liquefied gas include a gas holder provided on land (see FIG. 1) and a gas pipe connected to the gas holder. By driving the liquefied gas pump 31, the liquefied gas stored in the liquefied gas storage device 11 is sent to the liquefied gas supply line 3 and flows through the liquefied gas supply line 3 from the upstream side to the downstream side. , Is sent to the device 12 for liquefied gas. Further, by driving the circulation pump 44 for the working fluid, the working fluid circulates in the working fluid circulation line 4.

The cold heat recovery device 41 includes a turbine 42 configured to be driven by a working fluid flowing through a working fluid circulation line 4. In the illustrated embodiment, the cold heat recovery device 41 further includes a generator 43 configured to generate electricity by driving a turbine 42. The turbine 42 includes a turbine rotor 421 provided in the working fluid circulation line 4. The turbine rotor 421 is rotatably configured by the working fluid flowing through the working fluid circulation line 4. In some other embodiments, the cold heat recovery device 41 does not convert the rotational force of the turbine rotor 421 into electric power, but uses a power transmission device (for example, a coupling, a belt, a pulley, etc.) as power as it is. You may collect it.

The intermediate heat medium circulation line 6 is configured to circulate an intermediate heat medium having a freezing point lower than that of water. The heated water supply line 7 is configured to send heated water introduced from the outside of the cold heat recovery system 2. The "heated water" may be water at room temperature as long as it is water that heats the heat exchange target as a heat medium in the heat exchanger. The heating water is preferably water that is easily available on the ship 1 (for example, outboard water such as seawater or cooling water that cools the engine of the ship 1).

In the illustrated embodiment, the cold heat recovery system 2 includes a circulation pump 61 for an intermediate heat medium provided in the intermediate heat medium circulation line 6 and a heated water pump 71 provided in the heated water supply line 7. By driving the circulation pump 61 for the intermediate heat medium, the intermediate heat medium circulates in the intermediate heat medium circulation line 6. One end side 701 of the heated water supply line 7 is connected to a heated water supply source 13 provided outside the cold heat recovery system 2, and the other end side 702 is a hot water discharge destination provided outside the cold heat recovery system 2. Connected to 14. By driving the heating water pump 71, the heating water is sent from the heating water supply source 13 to the heating water supply line 7, flows through the heating water supply line 7 from the upstream side to the downstream side, and then heated. It is sent to the water discharge destination 14.

As the heating water supply source 13, for example, the intake port 17 (see FIG. 1) for introducing outboard water provided in the hull 10 and the cooling of the engine of the ship 1 (for example, the engine 16) are cooled. Examples thereof include a cooling water flow path 18 through which water flows (see FIG. 1). Further, as the discharge destination 14 of the heated water, for example, a discharge port 19 (see FIG. 1) for discharging water to the outside of the ship provided on the hull 10 and the like can be mentioned.

The intermediate heat medium may be the same type of heat medium as the working fluid, or may be a different type of heat medium. In the embodiment shown in FIG. 2, the intermediate heat medium is made of propane, and the heating water is made of cooling water (engine jacket water) after cooling the engine. The cooling water draws heat from the engine and has a higher temperature than seawater at room temperature. In the embodiment shown in FIG. 3, the intermediate heat medium is made of propane and the heated water is made of seawater obtained from the outside of the ship. In the embodiment shown in FIG. 4, the intermediate heat medium is made of antifreeze (specifically, glycol water), and the heated water is made of seawater obtained from the outside of the ship. For reference, FIGS. 2 to 4 show an example of the temperature and pressure in each flow path.

The first heat exchanger 51 is configured to exchange heat between the liquefied gas flowing through the liquefied gas supply line 3 and the working fluid flowing through the working fluid circulation line 4. In the illustrated embodiment, the first heat exchanger 51 is operated by a liquefied gas flow path 511 provided in the liquefied gas supply line 3 through which the liquefied gas flows and an operation in which the working fluid provided in the working fluid circulation line 4 flows. A fluid flow path 512 is formed. The working fluid flow path 512 is arranged at least partially adjacent to the liquefied gas flow path 511, and is located between the working fluid flowing through the working fluid flow path 512 and the liquefied gas flowing through the liquefied gas flow path 511. Heat exchange takes place.

The second heat exchanger 52 is configured to exchange heat between the working fluid flowing through the working fluid circulation line 4 and the intermediate heat medium flowing through the intermediate heat medium circulation line 6. In the illustrated embodiment, the second heat exchanger 52 has a working fluid flow path 521 provided in the working fluid circulation line 4 through which the working fluid flows, and an intermediate heat medium provided in the intermediate heat medium circulation line 6. A flowing intermediate heat medium flow path 522 is formed. The intermediate heat medium flow path 522 is arranged at least partially adjacent to the working fluid flow path 521, and includes an intermediate heat medium flowing through the intermediate heat medium flow path 522 and a working fluid flowing through the working fluid flow path 521. Heat exchange takes place between them.

The third heat exchanger 53 is configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line 6 and the heated water flowing through the heated water supply line 7. In the illustrated embodiment, the third heat exchanger 53 includes an intermediate heat medium flow path 531 provided in the intermediate heat medium circulation line 6 through which the intermediate heat medium flows, and heated water provided in the heated water supply line 7. A heated water flow path 532 through which the water flows is formed. The heated water flow path 532 is arranged at least partially adjacent to the intermediate heat medium flow path 531 and is between the intermediate heat medium flowing through the heated water flow path 532 and the working fluid flowing through the intermediate heat medium flow path 531. Heat exchange takes place at.

The first heat exchanger 51 (specifically, the liquefied gas flow path 511) is provided on the downstream side of the liquefied gas pump 31 of the liquefied gas supply line 3 and on the upstream side of the liquefied gas device 12. .. The liquefied gas pump 31 is provided on the downstream side of the liquefied gas storage device 11 of the liquefied gas supply line 3. Further, the first heat exchanger 51 (specifically, the working fluid flow path 512) is provided on the downstream side of the turbine 42 of the working fluid circulation line 4 and on the upstream side of the circulation pump 44 for the working fluid. ..

The second heat exchanger 52 (specifically, the working fluid flow path 521) is provided on the downstream side of the working fluid circulation pump 44 of the working fluid circulation line 4 and on the upstream side of the turbine 42. Further, the second heat exchanger 52 (specifically, the intermediate heat medium flow path 522) is larger than the third heat exchanger (specifically, the intermediate heat medium flow path 531) of the intermediate heat medium circulation line 6. It is provided on the downstream side and on the upstream side of the circulation pump 61 for the intermediate heat medium.

The third heat exchanger (specifically, the heated water flow path 532) is provided on the downstream side of the heated water pump 71 of the heated water supply line 7 and on the upstream side of the heated water discharge destination 14. The heating water pump 71 is provided on the downstream side of the heating water supply source 13 of the heating water supply line 7.

The liquefied gas boosted by the liquefied gas pump 31 is sent to the liquefied gas flow path 511 of the first heat exchanger 51. The heat exchange in the first heat exchanger 51 heats the liquefied gas flowing through the liquefied gas flow path 511 and cools the working fluid flowing through the working fluid flow path 512. That is, the cold energy of the liquefied gas flowing through the liquefied gas flow path 511 is recovered by the working fluid flowing through the working fluid flow path 512. Due to the heat exchange in the first heat exchanger 51, the temperature of the working fluid flowing through the working fluid flow path 512 becomes lower than the freezing point of water (heated water).

The intermediate heat medium boosted by the circulation pump 61 for the intermediate heat medium is sent to the intermediate heat medium flow path 531 of the third heat exchanger 53. Further, the heated water boosted by the heated water pump 71 is sent to the heated water flow path 532. The heat exchange in the third heat exchanger 53 heats the intermediate heat medium flowing through the intermediate heat medium flow path 531.

The working fluid flow path 521 of the second heat exchanger 52 is cooled by the first heat exchanger 51, and then the working fluid boosted by the circulation pump 44 for the working fluid is sent. Further, the intermediate heat medium heated by the third heat exchanger 53 is sent to the intermediate heat medium flow path 522. The heat exchange in the second heat exchanger 52 heats the working fluid flowing through the working fluid flow path 521 and cools the intermediate heat medium flow path 522. Here, since the intermediate heat medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the low-temperature working fluid in the second heat exchanger. In the embodiment shown in FIGS. 2 to 4, in the cold heat recovery system 2, each device in the cold heat recovery system 2 is provided so that the intermediate heat medium flowing through the intermediate heat medium circulation line 6 has a temperature higher than the freezing point of water. Conditions have been determined.

The intermediate heat medium flowing through the intermediate heat medium flow path 531 of the third heat exchanger 53 has a higher temperature than the working fluid flowing through the working fluid flow path 521 of the second heat exchanger 52. In the illustrated embodiment, the intermediate heat medium flowing through the intermediate heat medium flow path 531 has a temperature higher than the freezing point of water (heated water). In this way, the intermediate heat medium is cooled by heat exchange with the working fluid in the second heat exchanger 52, but since the temperature higher than the freezing point of water is maintained even after cooling, the third heat exchanger It is possible to prevent the heated water from solidifying during the heat exchange between the intermediate heat medium and the heated water in 53.

FIG. 5 is a schematic configuration diagram schematically showing the overall configuration of the cold heat recovery system according to the comparative example. The cold heat recovery system 20 according to the comparative example includes a liquefied gas supply line 3, a working fluid circulation line 4, a cold heat recovery device 41, a heated water supply line 7, and a first heat exchanger 51. The cold heat recovery system 20 further includes a heat exchanger 50 configured to exchange heat between the working fluid flowing through the working fluid circulation line 4 and the heated water flowing through the heated water supply line 7. In the comparative example shown in FIG. 5, the liquefied gas is composed of liquefied natural gas, the working fluid is composed of R1234ZE, and the heated water is composed of seawater obtained from the outside of the ship. For reference, FIG. 5 shows an example of temperature and pressure in each flow path.

The heat exchanger 50 is the working fluid flow path 501 provided at a position corresponding to the above-mentioned second heat exchanger 52 (working fluid flow path 521) of the working fluid circulation line 4, and the above-mentioned heated water supply line 7. A heated water flow path 502 provided at a position corresponding to the third heat exchanger 53 (heated water flow path 532) is formed. The heated water flow path 502 is arranged at least partially adjacent to the working fluid flow path 501, and heat exchanges between the heated water flowing through the heated water flow path 502 and the working fluid flowing through the working fluid flow path 501. Is done.

The working fluid flowing through the working fluid flow path 501 is lower than the freezing point of water (heated water) like the working fluid flowing through the working fluid flow path 521. Therefore, there is a risk that the heated water will solidify due to heat exchange between the working fluid and the heated water in the heat exchanger 50, and the solidified heated water will freeze in the heated water flow path 502 of the heat exchanger 50, blocking the heat exchanger 50. is there.

As shown in FIGS. 2 to 4, the cold heat recovery system 2 according to some embodiments includes the above-mentioned working fluid circulation line 4, the above-mentioned cold heat recovery device 41 including the turbine 42, and the above-mentioned intermediate heat medium. The circulation line 6, the above-mentioned first heat exchanger 51, the above-mentioned second heat exchanger 52, and the above-mentioned third heat exchanger 53 are provided.

According to the above configuration, the cold heat recovery system 2 includes at least an intermediate heat medium circulation line 6, a second heat exchanger 52, and a third heat exchanger 53. In such a cold heat recovery system 2, the working fluid circulating in the working fluid circulation line 4 and the heated water indirectly exchange heat with each other via the intermediate heat medium circulating in the intermediate heat medium circulation line 6. , It is possible to prevent the heat medium (intermediate heat medium, heated water) from solidifying during heat exchange. As a result, it is possible to prevent the solidified heat medium from freezing on the heat exchangers (second heat exchanger 52, third heat exchanger 53) and blocking the heat exchanger.

Specifically, the working fluid circulating in the working fluid circulation line 4 becomes a low temperature below the freezing point of water due to heat exchange with the liquefied gas in the first heat exchanger 51. In the second heat exchanger 52, heat exchange is performed between the working fluid that has passed through the first heat exchanger 51 and has become cold and the intermediate heat medium that circulates in the intermediate heat medium circulation line 6. Since the intermediate heat medium has a lower freezing point than water, it is difficult to solidify during heat exchange with the low-temperature working fluid in the second heat exchanger 52. As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the second heat exchanger 52 and blocking the second heat exchanger 52.

On the other hand, in the third heat exchanger 53, heat is exchanged between the intermediate heat medium that has passed through the second heat exchanger 52 and has become cold and the heated water. The intermediate heat medium is cooled by heat exchange with the working fluid in the second heat exchanger 52, but since the temperature higher than the freezing point of water is maintained even after cooling, the intermediate heat exchanger 53 is intermediate in the third heat exchanger 53. It is possible to prevent the heated water from solidifying during heat exchange between the heat medium and the heated water. As a result, it is possible to prevent the solidified heated water from freezing to the third heat exchanger 53 and blocking the third heat exchanger 53.

Therefore, according to the above configuration, in the cold heat recovery system 2, the heat medium (intermediate heat medium, heated water) solidified in the heat exchangers (second heat exchanger 52, third heat exchanger 53) freezes. Since it is possible to suppress the heat exchanger from being blocked, the reliability of the cold heat recovery system 2 when using a small heat exchanger can be improved.

In the embodiment shown in FIGS. 2 to 4, the above-described working fluid circulation line 4 branches from the downstream side of the second heat exchanger 52, bypasses the turbine 42, and bypasses the turbine 42, and is upstream of the first heat exchanger 51. Includes a bypass flow path 45 connected to. The main flow path 40 is a flow path other than the bypass flow path 45 of the working fluid circulation line 4 described above (a flow path that passes through the turbine 42 and the first heat exchanger 51). The bypass flow path 45 branches from the main flow path 40 at the branch portion 451 and joins the main flow path 40 at the merging portion 452. The cold heat recovery system 2 described above further includes an on-off valve 46 provided on the downstream side of the branch portion 451 of the main flow path 40 and on the upstream side of the turbine 42, and an on-off valve 47 provided in the bypass flow path 45. When the cold heat recovery system 2 is started, the on-off valve 46 is closed and the on-off valve 47 is opened to allow the working fluid to bypass the turbine 42. After the predetermined period has elapsed, the on-off valve 46 is opened, the on-off valve 47 is closed, and the turbine 42 is passed through the operating flow path.

In the embodiment shown in FIGS. 2 to 4, the above-described cold heat recovery system 2 is configured to evaporate the intermediate heat medium flowing through the intermediate heat medium circulation line 6 in the third heat exchanger 53, and the intermediate heat. The intermediate heat medium flowing through the medium circulation line 6 is configured to be condensed in the second heat exchanger 52. In this case, the overall efficiency of the cold heat recovery system 2 can be improved by utilizing latent heat or sensible heat.

In some embodiments, the cold heat recovery system 2 described above is the liquefied gas supply line 3 described above and the liquefied gas supply line 3 rather than the first heat exchanger 51, as shown in FIGS. 3 and 4. An auxiliary heat exchanger 81 provided on the downstream side is further provided. The auxiliary heat exchanger 81 exchanges heat between the liquefied gas flowing downstream of the first heat exchanger 51 of the liquefied gas supply line 3 and the heating medium circulating inside the cold heat recovery system 2. It is composed of.

In the illustrated embodiment, the heating medium has a lower freezing point than water. The auxiliary heat exchanger 81 includes a liquefied gas flow path 811 provided on the downstream side of the first heat exchanger of the liquefied gas supply line 3 through which the liquefied gas flows, and a heating medium that circulates inside the cold heat recovery system 2. A flowing heating medium flow path 812 is formed. The heating medium flow path 812 is arranged at least partially adjacent to the liquefied gas flow path 811, and includes a heating medium flowing through the heating medium flow path 812, a liquefied gas flow path 811 flowing through the liquefied gas flow path 811, and the like. Heat exchange takes place between them.

The liquefied gas heated by the first heat exchanger 51 is sent to the liquefied gas flow path 811 of the auxiliary heat exchanger 81. The heat exchange in the auxiliary heat exchanger 81 heats the liquefied gas flowing through the liquefied gas flow path 811 and cools the heating medium flowing through the heating medium flow path 812. Here, since the heating medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the liquefied gas in the auxiliary heat exchanger 81.

According to the above configuration, the cold heat recovery system 2 has a liquefied gas supply line 3, a first heat exchanger 51 provided in the liquefied gas supply line 3, and a liquefied gas supply line rather than the first heat exchanger 51. An auxiliary heat exchanger 81 provided on the downstream side of No. 3 is provided. In such a cold heat recovery system 2, the temperature of the liquefied gas is raised by heat exchange in the first heat exchanger 51 and the auxiliary heat exchanger 81, and the liquefied gas is vaporized. In this case, it is not necessary to raise the temperature to a temperature at which the liquid liquefied gas is completely vaporized by heat exchange in the first heat exchanger 51, so that the liquefied gas rises only in the first heat exchanger 51. The amount of heat exchanged in the first heat exchanger 51 can be reduced as compared with the case of performing temperature, and the temperature drop of the working fluid in the first heat exchanger 51 can be reduced. As a result, solidification of the intermediate heat medium can be effectively suppressed during heat exchange between the working fluid and the intermediate heat medium in the second heat exchanger 52. Further, by reducing the amount of heat exchange in the first heat exchanger 51, the size of the first heat exchanger 51 can be reduced.

In some embodiments, the cold heat recovery system 2 described above is configured such that the liquefied gas supply line 3 described above does not include a heat exchanger other than the first heat exchanger 51, as shown in FIG. ing. In this case, the liquefied gas is vaporized by heat exchange in the first heat exchanger 51. According to the above configuration, the structure of the cold heat recovery system 2 can be simplified.

In some embodiments, as shown in FIG. 3, the heating medium that exchanges heat with the liquefied gas in the auxiliary heat exchanger 81 described above is an intermediate heat medium circulation heated by the third heat exchanger 53. It consists of an intermediate heat medium flowing through the line 6. In this case, in the auxiliary heat exchanger 81, heat is generated between the liquefied gas that has passed through the first heat exchanger 51 and raised in temperature and the intermediate heat medium heated by the third heat exchanger 53. The exchange will take place. Since the intermediate heat medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the liquefied gas in the auxiliary heat exchanger 81. As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the auxiliary heat exchanger 81 and blocking the auxiliary heat exchanger 81. Therefore, the liquefied gas can be effectively heated by the auxiliary heat exchanger 81.

If a heat medium that circulates in a circulation line different from the intermediate heat medium circulation line 6 is used as the heat medium, a circulation pump for circulating the heat medium is required. According to the above configuration, by using the intermediate heat medium that circulates in the intermediate heat medium circulation line 6 as the heating medium, the circulation pump becomes unnecessary, so that the equipment cost of the cold heat recovery system 2 can be suppressed.

In some embodiments, as shown in FIG. 3, the above-mentioned intermediate heat medium circulation line 6 branches from the downstream side of the third heat exchanger 53 and bypasses the second heat exchanger 52. A bypass flow path 63 connected to the upstream side of the third heat exchanger 53 is included. The auxiliary heat exchanger 81 described above is configured to exchange heat between the liquefied gas flowing through the liquefied gas supply line 3 and the intermediate heat medium flowing through the bypass flow path 63.

As shown in FIG. 3, the main flow path is a flow path other than the bypass flow path 63 of the intermediate heat medium circulation line 6 described above (a flow path passing through the second heat exchanger 52 and the third heat exchanger 53). It is set to 62. In the illustrated embodiment, the cold heat recovery system 2 is provided on the downstream side of the second heat exchanger 52 of the main flow path 62 and on the upstream side of the circulation pump 61 for the intermediate heat medium to provide the intermediate heat medium. An intermediate heat medium storage device (for example, a buffer tank) 64 configured to store the intermediate heat medium and an intermediate heat medium that is provided downstream of the auxiliary heat exchanger 81 of the bypass flow path 63 and flows through the bypass flow path 63. A flow rate adjusting valve 65 configured to be able to adjust the flow rate is provided.

The bypass flow path 63 has one end side 631 connected to the downstream side of the third heat exchanger 53 of the main flow path 62 and the upstream side of the second heat exchanger 52, and the other end side 632 stores the intermediate heat medium. It is connected to the device 64. The intermediate heat medium that has passed through the bypass flow path 63 joins the intermediate heat medium that has passed through the second heat exchanger 52 of the main flow path 62 in the intermediate heat medium storage device 64. The other end side 632 of the bypass flow path 63 may be connected to the downstream side of the second heat exchanger 52 of the main flow path 62 and the upstream side of the intermediate heat medium storage device 64.

The flow rate adjusting valve 65 is provided on the downstream side of the auxiliary heat exchanger 81 (specifically, the heating medium flow path 812) of the bypass flow path 63. By adjusting the flow rate of the intermediate heat medium flowing through the bypass flow path 63 by the flow rate adjusting valve 65, the flow rate of the intermediate heat medium passing through the second heat exchanger 52 of the main flow path 62 is also adjusted.

Since the intermediate heat medium is a heat medium responsible for heating in the second heat exchanger 52 and the auxiliary heat exchanger 81, it is cooled by heat exchange in these heat exchangers. According to the above configuration, the auxiliary heat exchanger 81 is configured to exchange heat between the intermediate heat medium flowing through the bypass flow path 63 bypassing the second heat exchanger 52 and the liquefied gas. There is. That is, since the intermediate heat medium circulation line 6 does not have a flow path that passes through both the second heat exchanger 52 and the auxiliary heat exchanger 81, the intermediate heat medium circulation line 6 circulates in the intermediate heat medium. It is possible to prevent the temperature from becoming too low. As a result, it is possible to prevent the heated water from solidifying during heat exchange with the intermediate heat medium in the third heat exchanger 53.

In some embodiments, as shown in FIG. 4, the cold heat recovery system 2 described above circulates a second intermediate heat medium configured to circulate a second intermediate heat medium having a lower freezing point than water. Further line 9 is provided. The heating medium that exchanges heat with the liquefied gas in the auxiliary heat exchanger 81 described above includes a second intermediate heat medium that flows through the second intermediate heat medium circulation line 9. The heating medium flow path 812 of the auxiliary heat exchanger 81 is provided in the second intermediate heat medium circulation line 9.

In the illustrated embodiment, the cold heat recovery system 2 includes a circulation pump 91 for the second intermediate heat medium provided on the downstream side of the auxiliary heat exchanger 81 of the second intermediate heat medium circulation line 9. By driving the circulation pump 91, the second intermediate heat medium circulates in the second intermediate heat medium circulation line 9.
The second intermediate heat medium may be the same type of heat medium as the first intermediate heat medium which is the intermediate heat medium flowing through the intermediate heat medium circulation line 6, or may be a different type of heat medium. In the embodiment shown in FIG. 4, the second intermediate heat medium consists of R1234ZE.

According to the above configuration, the heating medium that exchanges heat with the liquefied gas in the auxiliary heat exchanger 81 includes a second intermediate heat medium that flows through the second intermediate heat medium circulation line 9. In this case, in the auxiliary heat exchanger 81, the liquefied gas that has passed through the first heat exchanger 51 and has been heated, and the second intermediate heat medium that circulates in the second intermediate heat medium circulation line 9. Heat exchange takes place between them. Since the second intermediate heat medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the liquefied gas in the auxiliary heat exchanger 81. As a result, it is possible to prevent the solidified second intermediate heat medium from freezing on the auxiliary heat exchanger 81 and blocking the auxiliary heat exchanger 81.

Further, according to the above configuration, by making the second intermediate heat medium circulation line 9 a line different from the intermediate heat medium circulation line 6, the intermediate heat medium circulation line 6 can be used as the second intermediate heat medium. A heat medium different from the circulating intermediate heat medium can be used. For example, as the second intermediate heat medium, a heat medium more suitable for the heat exchange conditions in the auxiliary heat exchanger 81 than the intermediate heat medium circulating in the intermediate heat medium circulation line 6 can be used.

In some embodiments, as shown in FIG. 4, the above-mentioned cold heat recovery system 2 is introduced from the outside of the cold heat recovery system 2 and the second intermediate heat medium flowing through the second intermediate heat medium circulation line 9. A second auxiliary heat exchanger 82 configured to exchange heat with the heated water is further provided.

In the illustrated embodiment, the second auxiliary heat exchanger 82 is a second intermediate through which the second intermediate heat medium provided on the downstream side of the circulation pump 91 of the second intermediate heat medium circulation line 9 flows. A heat medium flow path 821 and a heated water flow path 822 through which heated water introduced from the outside of the cold heat recovery system 2 flows are formed. At least a part of the heated water flow path 822 is arranged adjacent to the second intermediate heat medium flow path 821, and the heated water flowing through the heated water flow path 822 and the second intermediate heat medium flow path 821 flow through the heated water flow path 822. Heat exchange is performed between the intermediate heat medium of 2.

In the embodiment shown in FIG. 4, the heated water supply line 7 described above branches from the downstream side of the heated water pump 71 and upstream of the third heat exchanger 53, and the heated water discharge destination 14B Includes an auxiliary flow path 72 connected to. The heated water flow path 822 of the second auxiliary heat exchanger 82 is provided in the sub flow path 72. As shown in FIG. 4, a flow path other than the sub-flow path 72 of the heated water supply line 7 described above (a flow path passing through the heated water pump 71 and the third heat exchanger 53) is used as the main flow path 70. .. One end side 721 of the sub flow path 72 is connected to the downstream side of the heated water pump 71 of the main flow path 70 and the upstream side of the third heat exchanger 53, and the other end side 722 is the hot water discharge destination 14B. It is connected to the. In this case, since the heated water pump 71 can send the heated water to each of the main flow path 70 and the sub flow path 72, a dedicated pump for flowing the heated water to the sub flow path 72 becomes unnecessary, so that the cold heat can be recovered. The equipment cost of the system 2 can be suppressed. The other end side 722 of the sub flow path 72 may be connected to the downstream side of the third heat exchanger 53 of the main flow path 70 or to the discharge destination 14 of the heated water.

A second intermediate heat medium that has been cooled by the auxiliary heat exchanger 81 and then boosted by the circulation pump 91 is sent to the second intermediate heat medium flow path 821. Further, the heated water boosted by the heated water pump 71 is sent to the heated water flow path 822. The second intermediate heat medium flowing through the second intermediate heat medium flow path 821 has a lower temperature than the heated water flowing through the heated water flow path 822. The heat exchange in the second auxiliary heat exchanger 82 heats the second intermediate heat medium flowing through the second intermediate heat medium flow path 821. A second intermediate heat medium heated by the second auxiliary heat exchanger 82 is sent to the auxiliary heat exchanger 81.

In the illustrated embodiment, the second intermediate heat medium flowing through the second intermediate heat medium flow path 821 has a temperature higher than the freezing point of water (heated water). The second intermediate heat medium flowing through the second intermediate heat medium circulation line 9 is cooled by heat exchange with the liquefied gas in the auxiliary heat exchanger 81, but the temperature higher than the freezing point of water is maintained even after cooling. Therefore, it is possible to prevent the heated water from solidifying during heat exchange between the second intermediate heat medium and the heated water in the second auxiliary heat exchanger 82.

In the cold heat recovery system 2, the liquefied gas is heated by heat exchange in the first heat exchanger 51 and the auxiliary heat exchanger 81, so that the amount of heat exchange in the auxiliary heat exchanger 81 is small and the auxiliary heat exchanger 81. The amount of temperature decrease of the second intermediate heat medium (heating medium) in 81 is small. According to the above configuration, it is possible to prevent the heated water from solidifying during heat exchange between the second intermediate heat medium and the heated water in the second auxiliary heat exchanger 82.

In some embodiments, as shown in FIGS. 2-4, the above-mentioned cold heat recovery device 41 includes the above-mentioned turbine 42 and the above-mentioned generator 43 configured to generate electricity by driving the turbine 42. ,including. In this case, since the cold heat recovery device 41 includes the turbine 42 and the generator 43, power is generated by driving the turbine 42 with the working fluid that circulates in the working fluid circulation line 4 and recovers the cold energy from the liquefied gas. Power can be generated in the machine 43. In this case, the cold energy of the liquefied gas can be effectively utilized.

In some embodiments, the cold heat recovery system 2 described above comprises a liquefied gas supply line 3 configured to send liquefied gas from the liquefied gas storage device 11 and a liquefied gas supply, as shown in FIGS. At least a liquefied gas pump 31 provided on the line 3 is provided. The liquefied gas pump 31 is configured to be driven by the electric power generated by the generator 43. In the illustrated embodiment, the circulation pump 44, the circulation pump 61, the heating water pump 71, and the circulation pump 91 for the second intermediate heat medium are also configured to be driven by the electric power generated by the generator 43. It was done. Not all of the liquefied gas pump 31, the circulation pump 44, the circulation pump 61, the heated water pump 71, and the circulation pump 91 for the second intermediate heat medium, but one or more of them. The pump may be configured to be driven by the power generated by the generator 43.

According to the above configuration, the liquefied gas pump 31 provided in the liquefied gas supply line 3 can be driven by the electric power generated by the generator 43. In this case, since an electric power system for supplying electric power from the onshore electric power equipment to the liquefied gas pump 31 is not required, the ship 1 provided with the liquefied gas pump 31 can be miniaturized. Alternatively, since the occupied space of the cold heat recovery system 2 in the ship 1 can be reduced, the occupied space of the liquefied gas storage device 11 in the ship 1 can be increased.

FIG. 6 is an explanatory diagram for explaining an example of the heat exchanger according to the embodiment of the present disclosure.
In some embodiments, as shown in FIG. 6, the third heat exchanger 53 comprises a microchannel heat exchanger 53A. The microchannel heat exchanger 53A is a first microchannel 531A through which an intermediate heat medium flows, and a second microchannel 532A in which at least a part is arranged adjacent to the first microchannel 531A, and is heated water. Includes a second microchannel 532A through which

In the illustrated embodiment, the microchannel heat exchanger 53A has a first metal plate 533 on which a plurality of first microchannels 531A are formed and a second metal plate on which a plurality of second microchannels 532A are formed. It is composed of PCHE (Printed Metal Heat Exchanger) created by alternately stacking 534 and and joining them to each other. In some other embodiments, the microchannel heat exchanger 53A may be a plate heat exchanger or the like.

According to the above configuration, the third heat exchanger 53 allows heat exchange between the intermediate heat medium flowing through the first microchannel 531A and the heated water flowing through the second microchannel 532A. Since it is composed of a channel heat exchanger 53A, it is compact and can improve the heat transfer coefficient. Since the cold heat recovery system 2 using such a heat exchanger can reduce the occupied space of the cold heat recovery system 2 in the ship 1, the occupied space of the liquefied gas storage device 11 in the ship 1 can be increased. The heat exchangers other than the third heat exchanger 53 may also be microchannel heat exchangers.

As shown in FIG. 1, the ship 1 according to some embodiments includes the above-mentioned cold heat recovery system 2. In this case, the cold heat recovery system 2 can be miniaturized by using a small heat exchanger for the heat exchanger of the cold heat recovery system 2 (for example, the third heat exchanger 53). Therefore, the cold heat recovery system The size of the ship 1 provided with 2 can be reduced. Alternatively, since the occupied space of the cold heat recovery system 2 in the ship 1 can be reduced, the occupied space of the liquefied gas storage device 11 in the ship 1 can be increased.

FIG. 7 is a flow chart of a cold heat recovery method according to an embodiment of the present disclosure.
The cold heat recovery method 100 according to some embodiments is a cold heat recovery method by the above-mentioned cold heat recovery system 2 installed in the ship 1 having the liquefied gas storage device 11, and as shown in FIG. 7, the first cold heat recovery method 100 At least a heat exchange step S101, a second heat exchange step S102, and a third heat exchange step S103 are provided.

In the first heat exchange step S101, heat exchange is performed between the liquefied gas and the working fluid by the first heat exchanger 51. In the second heat exchange step S102, the second heat exchanger 52 exchanges heat between the working fluid that has exchanged heat with the liquefied gas in the first heat exchange step S101 and the intermediate heat medium. In the third heat exchange step S103, the third heat exchanger 53 exchanges heat between the intermediate heat medium that has exchanged heat with the working fluid in the second heat exchange step S102 and the heated water.

According to the above method, the first heat exchange step S101, the second heat exchange step S102, and the third heat exchange step S103 are provided. In such a cold heat recovery method 100, the working fluid circulating in the working fluid circulation line 4 and the heated water circulate in the intermediate heat medium circulation line 6 in the second heat exchange step S102 and the third heat exchange step S103. By indirectly performing heat exchange via the heat medium, it is possible to prevent the heat medium (intermediate heat medium, heated water) from solidifying during the heat exchange. As a result, it is possible to prevent the solidified heat medium from freezing on the heat exchangers (second heat exchanger 52, third heat exchanger 53) and blocking the heat exchanger.

Specifically, in the first heat exchange step S101, heat exchange is performed between the liquefied gas and the working fluid by the first heat exchanger 51. The working fluid that has passed through the first heat exchanger 51 has a low temperature below the freezing point of water. In the second heat exchange step S102, the second heat exchanger 52 between the working fluid whose temperature has become low due to the heat exchange in the first heat exchange step S101 and the intermediate heat medium flowing through the intermediate heat medium circulation line 6. Heat exchange takes place at. Since the intermediate heat medium has a lower freezing point than water, it is difficult to solidify during heat exchange with the low-temperature working fluid in the second heat exchange step S102. As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the second heat exchanger 52 and blocking the second heat exchanger 52.

On the other hand, in the third heat exchange step S103, the third heat exchanger 53 exchanges heat between the intermediate heat medium whose temperature has become low due to the heat exchange in the second heat exchange step S102 and the heated water. The intermediate heat medium is cooled by heat exchange with the working fluid in the second heat exchange step S102, but since the temperature higher than the freezing point of water is maintained even after cooling, the intermediate heat medium in the third heat exchange step S103 is maintained. It is possible to prevent the heated water from solidifying during heat exchange between the heated water and the heated water. As a result, it is possible to prevent the solidified heated water from freezing to the third heat exchanger 53 and blocking the third heat exchanger 53.

According to the above method, the heat medium (intermediate heat medium, heated water) solidified in the heat exchanger (second heat exchanger 52, third heat exchanger 53) freezes and closes the heat exchanger. Therefore, the reliability of the cold heat recovery system 2 when using a small heat exchanger can be improved.

As shown in FIG. 7, the cold heat recovery method 100 may further include a first auxiliary heat exchange step S201 and a second auxiliary heat exchange step S202. In the first auxiliary heat exchange step S201, the auxiliary heat exchanger 81 exchanges heat between the liquefied gas whose temperature has risen due to the heat exchange in the first heat exchange step S101 and the above-mentioned heating medium. In the second auxiliary heat exchange step S202, heat exchange is performed between the second intermediate heat medium flowing through the second intermediate heat medium circulation line 9 and the heated water by the second auxiliary heat exchanger 82. Be told.

The present disclosure is not limited to the above-described embodiment, and includes a modified form of the above-described embodiment and a combination of these embodiments as appropriate.

The contents described in some of the above-described embodiments are grasped as follows, for example.

1) The cold heat recovery system (2) according to at least one embodiment of the present disclosure is
A cold heat recovery system (2) installed on a ship (1) having a liquefied gas storage device (11) configured to store liquid liquefied gas.
A working fluid circulation line (4) configured to circulate a working fluid with a lower freezing point than water, and
A cold heat recovery device (41) including a turbine (42) configured to be driven by the working fluid flowing through the working fluid circulation line (4).
A first heat exchanger (51) configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line (4).
An intermediate heat medium circulation line (6) configured to circulate an intermediate heat medium having a lower freezing point than water, and an intermediate heat medium circulation line (6).
A second heat exchanger (52) provided on the downstream side of the working fluid circulation line (4) with respect to the first heat exchanger (51) and flowing through the working fluid circulation line (4). A second heat exchanger (52) configured to exchange heat between the working fluid and the intermediate heat medium flowing through the intermediate heat medium circulation line (6).
A third heat exchange configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line (6) and the heated water introduced from the outside of the cold heat recovery system (2). It is equipped with a vessel (53).

According to the configuration of 1) above, the cold heat recovery system (2) includes an intermediate heat medium circulation line (6), a second heat exchanger (52), and a third heat exchanger (53). Be prepared. In such a cold heat recovery system (2), the working fluid circulating in the working fluid circulation line (4) and the heated water indirectly pass through the intermediate heat medium circulating in the intermediate heat medium circulation line (6). By performing heat exchange, it is possible to prevent the heat medium (intermediate heat medium, heated water) from solidifying during the heat exchange. As a result, it is possible to prevent the solidified heat medium from freezing on the heat exchangers (second heat exchanger 52, third heat exchanger 53) and blocking the heat exchanger.

Specifically, the working fluid circulating in the working fluid circulation line (4) becomes a low temperature below the freezing point of water due to heat exchange with the liquefied gas in the first heat exchanger (51). In the second heat exchanger (52), between the working fluid that has passed through the first heat exchanger (51) and becomes cold and the intermediate heat medium that circulates in the intermediate heat medium circulation line (6). Heat exchange takes place. Since the intermediate heat medium has a lower freezing point than water, it is difficult to solidify during heat exchange with the low-temperature working fluid in the second heat exchanger (52). As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the second heat exchanger (52) and blocking the second heat exchanger (52).

On the other hand, in the third heat exchanger (53), heat is exchanged between the intermediate heat medium that has passed through the second heat exchanger (51) and has become cold and the heated water. The intermediate heat medium is cooled by heat exchange with the working fluid in the second heat exchanger (51), but since the temperature maintained higher than the freezing point of water is maintained even after cooling, the third heat exchanger (3rd heat exchanger (51) It is possible to prevent the heated water from solidifying during the heat exchange between the intermediate heat medium and the heated water in 53). As a result, it is possible to prevent the solidified heated water from freezing to the third heat exchanger (53) and blocking the third heat exchanger (53).

According to the above configuration, in the cold heat recovery system (2), the heat medium (intermediate heat medium, heated water) solidified in the heat exchangers (second heat exchanger 52, third heat exchanger 53) freezes. Since it is possible to suppress the heat exchanger from being blocked, the reliability of the cold heat recovery system (2) when using a small heat exchanger can be improved.

2) In some embodiments, the cold heat recovery system (2) described in 1) above is
A liquefied gas supply line (3) configured to send the liquefied gas from the liquefied gas storage device (11), and
An auxiliary heat exchanger (81) provided on the downstream side of the liquefied gas supply line (3) with respect to the first heat exchanger (51), and the liquefied gas flowing through the liquefied gas supply line (3). And an auxiliary heat exchanger (81) configured to exchange heat with the heating medium circulating inside the cold heat recovery system (2).

According to the configuration of 2) above, the cold heat recovery system (2) includes a liquefied gas supply line (3), the first heat exchanger (51) described above, and an auxiliary heat exchanger (81). .. In such a cold heat recovery system (2), the temperature of the liquefied gas is raised by heat exchange in the first heat exchanger (51) and the auxiliary heat exchanger (81), and the liquefied gas is vaporized. In this case, it is not necessary to raise the temperature to a temperature at which the liquid liquefied gas is completely vaporized by heat exchange in the first heat exchanger (51), so that only the first heat exchanger (51) is used. Compared with the case where the temperature of the liquefied gas is raised, the amount of heat exchange in the first heat exchanger (51) can be reduced, and the temperature of the working fluid in the first heat exchanger (51) can be lowered. It can be reduced. As a result, solidification of the intermediate heat medium can be effectively suppressed during heat exchange between the working fluid and the intermediate heat medium in the second heat exchanger (52). Further, by reducing the amount of heat exchange in the first heat exchanger (51), the size of the first heat exchanger (51) can be reduced.

3) In some embodiments, the cold heat recovery system (2) described in 2) above is used.
The heating medium comprises the intermediate heat medium that has been heated by the third heat exchanger (53) and flows through the intermediate heat medium circulation line (6).

According to the configuration of 3) above, in the auxiliary heat exchanger (81), the liquefied gas that has passed through the first heat exchanger (51) and has been heated is heated by the third heat exchanger (53). Heat exchange takes place between the intermediate heat medium and the intermediate heat medium. Since the intermediate heat medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the liquefied gas in the auxiliary heat exchanger (81). As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the auxiliary heat exchanger (81) and blocking the auxiliary heat exchanger (81). Therefore, the liquefied gas can be effectively heated by the auxiliary heat exchanger (81).

If the heating medium is a heat medium that circulates in a circulation line different from the intermediate heat medium circulation line (6), a circulation pump for circulating the heat medium is required. According to the configuration of 3) above, by using the heating medium as an intermediate heat medium that circulates in the intermediate heat medium circulation line (6), the circulation pump becomes unnecessary, so that the equipment cost of the cold heat recovery system (2) is reduced. It can be suppressed.

4) In some embodiments, the cold heat recovery system (2) according to 3) above.
The intermediate heat medium circulation line (6) branches from the downstream side of the third heat exchanger (53), bypasses the second heat exchanger (52), and bypasses the second heat exchanger (52). Includes a bypass flow path (63) connected to the upstream side of 53).
The auxiliary heat exchanger (81) is configured to exchange heat between the liquefied gas flowing through the liquefied gas supply line (3) and the intermediate heat medium flowing through the bypass flow path (63). It was.

Since the intermediate heat medium is a heat medium responsible for heating in the second heat exchanger (52) and the auxiliary heat exchanger (81), it is cooled by heat exchange in these heat exchangers. According to the configuration of 4) above, the auxiliary heat exchanger (81) heats between the intermediate heat medium flowing through the bypass flow path (63) bypassing the second heat exchanger (52) and the liquefied gas. It is configured to perform exchanges. That is, since the intermediate heat medium circulation line (6) does not have a flow path that passes through both the second heat exchanger (52) and the auxiliary heat exchanger (81), the intermediate heat medium circulation line (6) is not formed. ) Can be prevented from becoming too low in the temperature of the intermediate heat medium circulating. As a result, it is possible to prevent the heated water from solidifying during heat exchange with the intermediate heat medium in the third heat exchanger (53).

5) In some embodiments, the cold heat recovery system (2) described in 2) above is
Further comprising a second intermediate heat medium circulation line (9) configured to circulate a second intermediate heat medium having a lower freezing point than water.
The heating medium comprises the second intermediate heat medium flowing through the second intermediate heat medium circulation line (9).

According to the configuration of 5) above, the heating medium that exchanges heat with the liquefied gas in the auxiliary heat exchanger (81) is composed of a second intermediate heat medium that flows through the second intermediate heat medium circulation line (9). In this case, in the auxiliary heat exchanger (81), the liquefied gas that has passed through the first heat exchanger (51) and has been heated to a higher temperature and the second intermediate heat medium circulation line (9) are circulated. Heat exchange takes place between the intermediate heat medium and. Since the second intermediate heat medium has a lower freezing point than water, it is possible to suppress solidification during heat exchange with the liquefied gas in the auxiliary heat exchanger (81). As a result, it is possible to prevent the solidified second intermediate heat medium from freezing on the auxiliary heat exchanger (81) and blocking the auxiliary heat exchanger (81).

Further, according to the configuration of 5) above, the second intermediate heat medium circulation line (9) is set to a line different from the intermediate heat medium circulation line (6), so that the second intermediate heat medium is intermediate. A heat medium different from the intermediate heat medium that circulates in the heat medium circulation line (6) can be used. For example, as the second intermediate heat medium, a heat medium more suitable for the heat exchange conditions in the auxiliary heat exchanger (81) than the intermediate heat medium circulating in the intermediate heat medium circulation line (6) can be used.

6) In some embodiments, the cold heat recovery system (2) according to 5) above is
It is configured to exchange heat between the second intermediate heat medium flowing through the second intermediate heat medium circulation line (9) and the heated water introduced from the outside of the cold heat recovery system (2). A second auxiliary heat exchanger (82) is further provided.

In the cold heat recovery system (2), the liquefied gas is heated by heat exchange in the first heat exchanger (51) and the auxiliary heat exchanger (81), so that the heat exchange in the auxiliary heat exchanger (81) is performed. The amount is small, and the amount of temperature decrease of the second intermediate heat medium (heating medium) in the auxiliary heat exchanger (81) is small. According to the configuration of 6) above, it is possible to prevent the heated water from solidifying during heat exchange between the second intermediate heat medium and the heated water in the second auxiliary heat exchanger (82).

7) In some embodiments, the cold heat recovery system (2) according to any one of 1) to 6) above.
The cold heat recovery device (41) further includes a generator (43) configured to generate electricity by driving the turbine (42).

According to the configuration of 7) above, since the cold heat recovery device (41) includes the turbine (42) and the generator (43), the cold heat energy is recovered from the liquefied gas by circulating in the working fluid circulation line (4). By driving the turbine (42) with the working fluid, power can be generated in the generator (43). In this case, the cold energy of the liquefied gas can be effectively utilized.

8) In some embodiments, the cold heat recovery system (2) according to 7) above is
A liquefied gas supply line (3) configured to send the liquefied gas from the liquefied gas storage device (11), and
A liquefied gas pump (31) provided in the liquefied gas supply line (3) is further provided.
The liquefied gas pump (31) was configured to be driven by the electric power generated by the generator (43).

According to the configuration of 8) above, the liquefied gas pump (31) provided in the liquefied gas supply line (3) can be driven by the electric power generated by the generator (43). In this case, since an electric power system for supplying electric power from the onshore electric power equipment to the liquefied gas pump (31) is not required, the ship (1) equipped with the liquefied gas pump (31) can be miniaturized. .. Alternatively, since the occupied space of the cold heat recovery system (2) in the ship (1) can be reduced, the occupied space of the liquefied gas storage device (11) in the ship (1) can be increased.

9) In some embodiments, the cold heat recovery system (2) according to any one of 1) to 8) above.
The third heat exchanger (53)
The first microchannel (531A) through which the intermediate heat medium flows, and
A micro containing at least a part of the first microchannel (531A) adjacent to the first microchannel (532A), the second microchannel (532A) through which the heated water flows. It consists of a channel heat exchanger (53A).

According to the configuration of 9) above, the third heat exchanger (53) is composed of an intermediate heat medium flowing through the first microchannel (531A) and heated water flowing through the second microchannel (532A). Since it is composed of a microchannel heat exchanger (53A) capable of heat exchange between them, it is compact and can improve the heat transfer coefficient.

10) The vessel (1) according to at least one embodiment of the present disclosure is
The cold heat recovery system (2) according to any one of 1) to 9) above is provided.

According to the configuration of 10) above, the cold heat recovery system (2) can be miniaturized by using a small heat exchanger, so that the ship (1) equipped with the cold heat recovery system (2) can be miniaturized. Alternatively, since the occupied space of the cold heat recovery system (2) in the ship (1) can be reduced, the occupied space of the liquefied gas storage device (11) in the ship (1) can be increased.

11) The cold heat recovery method (100) according to at least one embodiment of the present disclosure is
A cold heat recovery method (100) by a cold heat recovery system (2) installed on a ship (1) having a liquefied gas storage device (11) configured to store liquid liquefied gas.
The cold heat recovery system (2) is
A working fluid circulation line (4) configured to circulate a working fluid with a lower freezing point than water, and
A cold heat recovery device (41) including a turbine (42) configured to be driven by the working fluid flowing through the working fluid circulation line (4).
A first heat exchanger (51) configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line (4).
An intermediate heat medium circulation line (6) configured to circulate an intermediate heat medium having a lower freezing point than water, and an intermediate heat medium circulation line (6).
A second heat exchanger (52) provided on the downstream side of the working fluid circulation line (4) with respect to the first heat exchanger (51) and flowing through the working fluid circulation line (4). A second heat exchanger (52) configured to exchange heat between the working fluid and the intermediate heat medium flowing through the intermediate heat medium circulation line (6).
A third heat exchange configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line (6) and the heated water introduced from the outside of the cold heat recovery system (2). Equipped with a vessel (53)
The cold heat recovery method (100) is
A first heat exchange step (S101) in which heat is exchanged between the liquefied gas and the working fluid by the first heat exchanger (51).
The second heat that exchanges heat between the working fluid that has exchanged heat with the liquefied gas in the first heat exchange step (S101) by the second heat exchanger (52) and the intermediate heat medium. Exchange step (S102) and
The third heat that exchanges heat between the intermediate heat medium that has exchanged heat with the working fluid in the second heat exchange step (S102) by the third heat exchanger (53) and the heated water. A replacement step (S103) is provided.

According to the method of 11) above, the first heat exchange step (S101), the second heat exchange step (S102), and the third heat exchange step (S103) are provided. In such a cold heat recovery method (100), the working fluid circulating in the working fluid circulation line (4) and the heated water are intermediately heated by the second heat exchange step (S102) and the third heat exchange step (S103). By indirectly performing heat exchange via the intermediate heat medium circulating in the medium circulation line (6), it is possible to suppress solidification of the heat medium (intermediate heat medium, heated water) during heat exchange. it can. As a result, it is possible to prevent the solidified heat medium from freezing on the heat exchangers (second heat exchanger 52, third heat exchanger 53) and blocking the heat exchanger.

Specifically, in the first heat exchange step (S101), heat exchange is performed between the liquefied gas and the working fluid by the first heat exchanger (51). The working fluid that has passed through the first heat exchanger (51) has a low temperature below the freezing point of water. In the second heat exchange step (S102), the second heat exchanger (52) connects the working fluid whose temperature has become low due to the heat exchange in the first heat exchange step (S101) and the intermediate heat medium circulation line (6). Heat exchange takes place between the flowing intermediate heat medium. Since the intermediate heat medium has a lower freezing point than water, it is difficult to solidify during heat exchange with a low-temperature working fluid in the second heat exchange step. As a result, it is possible to prevent the solidified intermediate heat medium from freezing on the second heat exchanger (52) and blocking the second heat exchanger (52).

On the other hand, in the third heat exchange step (S103), the intermediate heat medium whose temperature has become low due to the heat exchange in the second heat exchange step (S102) by the third heat exchanger (53) and the heated water. Heat exchange takes place. The intermediate heat medium is cooled by heat exchange with the working fluid in the second heat exchange step (S102), but since the temperature higher than the freezing point of water is maintained even after cooling, the intermediate heat in the third heat exchange step is maintained. It is possible to prevent the heated water from solidifying during heat exchange between the medium and the heated water. As a result, it is possible to prevent the solidified heated water from freezing to the third heat exchanger (53) and blocking the third heat exchanger (53).

According to the above method, the heat medium (intermediate heat medium, heated water) solidified in the heat exchanger (second heat exchanger 52, third heat exchanger 53) freezes and closes the heat exchanger. Therefore, the reliability of the cold heat recovery system (2) when using a small heat exchanger can be improved.

1 Ship 2 Cold heat recovery system 20 Cold heat recovery system according to a comparative example 3 Liquefied gas supply line 301 One end side 302 The other end side 31 Liquefied gas pump 4 Working fluid circulation line 41 Cold heat recovery device 42 Turbine 421 Turbine rotor 43 Generator 44 ( Circulation pump 50 (for working fluid) Heat exchanger 501 (comparative example) Working fluid flow path 502 Heating water flow path 51 First heat exchanger 511 Liquefied gas flow path 512 Working fluid flow path 52 Second heat exchanger 521 Working fluid flow path 522 Intermediate heat medium flow path 53 Third heat exchanger 531 Intermediate heat medium flow path 531A First microchannel 532 Heating water flow path 532A Second microchannel 6 Intermediate heat medium circulation line 61 (intermediate heat medium) Circulation pump 62 Main flow path 63 Bypass flow path 631 One end side 632 One end side 64 Intermediate heat medium storage device 65 Flow control valve 7 Heating water supply line 701 One end side 702 The other end side 71 Heating water pump 81 Auxiliary heat exchange Vessel 811 Liquefied gas flow path 812 Heating medium flow path 82 Second auxiliary heat exchanger 821 Second intermediate heat medium flow path 822 Heating water flow path 9 Second intermediate heat medium circulation line 10 Ship body 11 Liquefied gas storage device 12 Equipment 13 Heated water supply source 14 Heated water discharge destination 15 Engine room 16 Engine 17 Intake port 18 Cooling water flow path 19 Discharge port

Claims

A cold heat recovery system installed on a ship that has a liquefied gas storage device configured to store liquid liquefied gas.
A working fluid circulation line configured to circulate a working fluid with a lower freezing point than water,
A cold heat recovery device including a turbine configured to be driven by the working fluid flowing through the working fluid circulation line.
A first heat exchanger configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line.
An intermediate heat medium circulation line configured to circulate an intermediate heat medium having a lower freezing point than water,
A second heat exchanger provided on the downstream side of the working fluid circulation line with respect to the first heat exchanger, the working fluid flowing through the working fluid circulation line and the intermediate heat medium circulation line flowing through the working fluid circulation line. A second heat exchanger configured to exchange heat with the intermediate heat medium,
Cold heat including the intermediate heat medium flowing through the intermediate heat medium circulation line and a third heat exchanger configured to exchange heat between the intermediate heat medium and the heated water introduced from the outside of the cold heat recovery system. Recovery system.
A liquefied gas supply line configured to send the liquefied gas from the liquefied gas storage device, and
An auxiliary heat exchanger provided on the downstream side of the liquefied gas supply line with respect to the first heat exchanger, and the liquefied gas flowing through the liquefied gas supply line and heating circulating inside the cold heat recovery system. The cold heat recovery system according to claim 1, further comprising an auxiliary heat exchanger configured to exchange heat with the medium.
The heating medium comprises the intermediate heat medium that has been heated by the third heat exchanger and flows through the intermediate heat medium circulation line.
The cold heat recovery system according to claim 2.
The intermediate heat medium circulation line is a bypass flow path that branches from the downstream side of the third heat exchanger, bypasses the second heat exchanger, and is connected to the upstream side of the third heat exchanger. Including
The auxiliary heat exchanger is configured to exchange heat between the liquefied gas flowing through the liquefied gas supply line and the intermediate heat medium flowing through the bypass flow path.
The cold heat recovery system according to claim 3.
Further provided with a second intermediate heat medium circulation line configured to circulate a second intermediate heat medium having a lower freezing point than water.
The heating medium comprises the second intermediate heat medium flowing through the second intermediate heat medium circulation line.
The cold heat recovery system according to claim 2.
A second auxiliary heat configured to exchange heat between the second intermediate heat medium flowing through the second intermediate heat medium circulation line and the heated water introduced from the outside of the cold heat recovery system. The cold heat recovery system according to claim 5, further comprising a exchanger.
The cold heat recovery device further includes a generator configured to generate electricity by driving the turbine.
The cold heat recovery system according to any one of claims 1 to 6.
A liquefied gas supply line configured to send the liquefied gas from the liquefied gas storage device, and
A pump for liquefied gas provided in the liquefied gas supply line is further provided.
The cold heat recovery system according to claim 7, wherein the liquefied gas pump is configured to be driven by electric power generated by the generator.
The third heat exchanger is
The first microchannel through which the intermediate heat medium flows, and
A second microchannel that is arranged at least in part adjacent to the first microchannel and through which the heated water flows, and a second microchannel.
Consists of a microchannel heat exchanger, including
The cold heat recovery system according to any one of claims 1 to 8.
A ship equipped with the cold heat recovery system according to any one of claims 1 to 9.
A cold heat recovery method using a cold heat recovery system installed on a ship having a liquefied gas storage device configured to store liquid liquefied gas.
The cold heat recovery system
A working fluid circulation line configured to circulate a working fluid with a lower freezing point than water,
A cold heat recovery device including a turbine configured to be driven by the working fluid flowing through the working fluid circulation line.
A first heat exchanger configured to exchange heat between the liquefied gas and the working fluid flowing through the working fluid circulation line.
An intermediate heat medium circulation line configured to circulate an intermediate heat medium having a lower freezing point than water,
A second heat exchanger provided on the downstream side of the working fluid circulation line with respect to the first heat exchanger, the working fluid flowing through the working fluid circulation line and the intermediate heat medium circulation line flowing through the working fluid circulation line. A second heat exchanger configured to exchange heat with the intermediate heat medium,
A third heat exchanger configured to exchange heat between the intermediate heat medium flowing through the intermediate heat medium circulation line and the heated water introduced from the outside of the cold heat recovery system is provided.
The cold heat recovery method is
A first heat exchange step in which heat is exchanged between the liquefied gas and the working fluid by the first heat exchanger.
A second heat exchange step in which heat is exchanged between the working fluid that has undergone heat exchange with the liquefied gas in the first heat exchange step by the second heat exchanger and the intermediate heat medium.
The third heat exchanger includes an intermediate heat medium that exchanges heat with the working fluid in the second heat exchange step, and a third heat exchange step that exchanges heat between the heated water. Cold heat recovery method.