JP2022137961A - Cold recovery system and ship or floating body - Google Patents

Abstract

To provide a cold recovery system that can improve the output and reliability of the cold recovery system, and a ship or a floating body.SOLUTION: A cold recovery system comprises: a first heat exchanger constituted so as to vaporize liquefied gas; a liquefied gas supply line for supplying the liquefied gas to the first heat exchanger from a liquefied gas storage device; a cold recovery cycle constituted so as to circulate a heat medium for cold heat-exchanged with the liquefied gas in the first heat exchanger, and including a turbine for cold constituted so as to be driven by the heat medium for cold; and a second heat exchanger constituted so as to exchange heat between the heat medium for cold flowing between the turbine for cold and the first heat exchanger in the cold recovery cycle, and external water introduced from the outside of the cold recovery cycle.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to a cold energy recovery system for recovering cold energy of liquefied gas, and a vessel or floating body provided with the cold energy recovery system.

Liquefied gas (e.g., liquefied natural gas) is liquefied for the purpose of transportation and storage. When supplied to supply destinations such as city gas and thermal power plants, it is heated and vaporized by a heat medium such as seawater. will be When the liquefied gas is vaporized, the cold energy of the liquefied gas is sometimes recovered instead of being dumped into seawater (for example, Patent Document 1).

Patent Literature 1 discloses a cryogenic power generation cycle that recovers cold energy of liquefied gas as electric power. A secondary medium Rankine cycle system or the like is known as this cold-heat power generation cycle (see Patent Document 1). In the secondary medium Rankine cycle system, the secondary medium circulating in a closed loop is heated by an evaporator using seawater as a heat source to evaporate. , liquefied natural gas to cool and condense.

It is difficult to set up land-use LNG terminals corresponding to each supply destination of liquefied natural gas, because it is costly to secure land. For this reason, vessels equipped with LNG storage facilities for storing liquefied natural gas and regasification facilities for regasifying liquefied natural gas are moored offshore, and the liquefied natural gas regasified by the vessel is transferred to pipelines. It may be sent to land supply destinations or offshore power gauges (floating power plants) via.

Ships are less expandable than onshore facilities, so in order to install cryogenic power generation equipment, it is important to downsize the cryogenic power generation system, especially the size of the heat exchanger. Small heat exchangers include, for example, printed circuit heat exchangers (PCHEs) and plate heat exchangers.

Japanese Utility Model Laid-Open No. 61-59803

When the temperature of the other heat exchange object is lower than the freezing point of one heat exchange object, the one heat exchange object solidifies in the heat exchange in the heat exchanger, and the solidified heat exchange object is on the surface of the heat exchanger. There is a risk that it will adhere and clog the heat exchanger. A small-sized heat exchanger has a higher risk of clogging than a large-sized heat exchanger (for example, a shell-tube type heat exchanger), so there is a reliability problem.

By the way, in order to increase the power output, a combined cycle is conceivable in which the above-mentioned cryogenic power generation cycle and a direct expansion turbine driven by the expansion energy of the vaporized gas obtained by vaporizing the liquefied gas are combined. In order to improve the output of this combined cycle, it is conceivable to heat the vaporized gas supplied to the direct expansion turbine with seawater to raise the temperature, but the heat exchanger that exchanges heat between the vaporized gas and seawater is clogged. there is a risk of

In view of the circumstances described above, an object of at least one embodiment of the present disclosure is to provide a cold recovery system and a vessel or floating body that can improve the output and reliability of the cold recovery system.

A cold energy recovery system according to an embodiment of the present disclosure includes:
A cold heat recovery system installed in a ship or floating body having a liquefied gas storage device configured to store liquefied gas,
a first heat exchanger configured to vaporize the liquefied gas;
a liquefied gas supply line for supplying the liquefied gas from the liquefied gas storage device to the first heat exchanger;
A cold heat recovery cycle configured to circulate a cold heat medium heat-exchanged with the liquefied gas in the first heat exchanger, wherein the cold heat recovery cycle is configured to be driven by the cold heat medium. a cold recovery cycle including a turbine for
Heat exchange is performed between the cold heat medium flowing between the cold heat turbine and the first heat exchanger in the cold heat recovery cycle and external water introduced from the outside of the cold heat recovery system. and a second heat exchanger configured to:

A vessel or floating body according to an embodiment of the present disclosure includes the cold energy recovery system.

According to at least one embodiment of the present disclosure, a cold energy recovery system capable of improving the output and reliability of the cold energy recovery system, and a vessel or floating body including the cold energy recovery system are provided.

1 is a schematic configuration diagram schematically showing the configuration of a vessel or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure; FIG. FIG. 2 is a schematic configuration diagram schematically showing the configuration of a ship or floating body provided with a cold energy recovery system according to a comparative example; 1 is a schematic configuration diagram schematically showing the configuration of a vessel or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure; FIG. 1 is a schematic configuration diagram schematically showing the configuration of a vessel or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure; FIG.

Several embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiment or shown in the drawings are not meant to limit the scope of the present disclosure, but are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, 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, expressions that express shapes such as squares and cylinders do not only represent shapes such as squares and cylinders in a geometrically strict sense, but also include irregularities and chamfers to the extent that the same effect can be obtained. The shape including the part etc. shall also be represented.
On the other hand, the expressions "comprising", "including", or "having" one component are not exclusive expressions excluding the presence of other components.
In addition, the same code|symbol may be attached|subjected about the same structure and description may be abbreviate|omitted.

(ships, floating bodies)
FIG. 1 is a schematic configuration diagram schematically showing the configuration of a ship or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure. A cold energy recovery system 1 according to some embodiments is installed in a ship 10A or a floating body 10B, as shown in FIG. The ship 10A and the floating body 10B are structures that can float on water, and have a liquefied gas storage device (for example, a liquefied gas tank) 11 configured to store liquefied gas. The ship 10A has a propulsion device (not shown) such as a propeller, and a propulsion device (not shown) configured to drive the propulsion device, and is self-propelled by driving the propulsion device. is the body. The floating body 10B is a non-self-propellable structure that does not have a propulsion device for self-propelling like the ship 10A.

(cold heat recovery system)
Cold heat recovery system 1, as shown in FIG. A liquefied gas supply line 2 for supplying the liquefied gas, a vaporized gas supply line 3 for supplying the vaporized gas generated by vaporizing the liquefied gas in the heat exchanger 12, and liquefaction in the heat exchanger 12 and a cooling heat recovery cycle 4 configured to circulate the cooling heat transfer medium heat-exchanged with the gas. Vaporized gas is led to a gas supply destination 13 through a vaporized gas supply line 3 .

Hereinafter, liquefied natural gas (LNG) will be described as a specific example of the liquefied gas supplied from the liquefied gas storage device 11, and propane will be described as a specific example of the cold heat transfer medium flowing through the cold heat recovery cycle 4. The disclosure is also applicable when liquefied gas (liquefied petroleum gas, liquid hydrogen, etc.) other than liquefied natural gas is used as liquefied gas supplied from the liquefied gas storage device 11, and a heat medium other than propane ( For example, an organic medium can be used as a heat medium for cold heat flowing through the cold heat recovery cycle 4 . Note that the cooling/heating medium has a boiling point and a freezing point lower than those of water.

(First heat exchanger)
The heat exchanger 12 is configured to exchange heat between the liquefied gas sent from the liquefied gas supply line 2 and the cold heat medium flowing through the cold heat recovery cycle 4 . The heat exchanger 12 includes a one side passage 121 through which the liquefied gas sent from the liquefied gas supply line 2 flows, and the other side passage 122 through which the cold heat medium provided in the cold heat recovery cycle 4 flows. In the heat exchanger 12, heat is exchanged between the one-side passage 121 and the other-side passage 122, and the cold energy of the liquefied gas flowing through the one-side passage 121 is transferred to the cooling heat medium flowing through the other-side passage 122. be recovered. As a result, the liquefied gas flowing through the one-side passage 121 is heated and vaporized. Also, the cooling/heating medium flowing through the other side passage 122 is cooled.

(Liquefied gas supply line, vaporized gas supply line)
The liquefied gas supply line 2 includes a liquefied gas flow path 20 having one side connected to the liquefied gas storage device 11 and the other side connected to the upstream end of the one side passage 121 of the heat exchanger 12 . The vaporized gas supply line 3 includes a vaporized gas flow path 30 having one side connected to the downstream end of the one side passage 121 of the heat exchanger 12 and the other side connected to the vaporized gas supply destination 13 . The one-side passage 121 of the heat exchanger 12 includes a flow path (pipe line) that connects the liquefied gas flow path 20 and the vaporized gas flow path 30 . Each of the one-side passage 121 of the heat exchanger 12, the liquefied gas passage 20, and the vaporized gas passage 30 is configured to allow the liquefied gas and the vaporized gas obtained by vaporizing the liquefied gas to flow therethrough. The supply destination 13 of the vaporized gas may be facilities provided outside the ship 10A or the floating body 10B (for example, power generation facilities or gas storage facilities on land, or facilities mounted on the ship 10A or the floating body 10B). may be

(gas pump)
The liquefied gas supply line 2 further includes a gas pump 21 provided in the liquefied gas flow path 20 . The gas pump 21 is configured to send the liquefied gas to the downstream side of the liquefied gas flow path 20 (that is, the side where the heat exchanger 12 is located). In the illustrated embodiment, the gas pump 21 includes rotor blades 211 provided in the liquefied gas flow path 20, and an electric motor 212 configured to supply the rotor blades 211 with driving force for rotating the rotor blades 211. ,including. By driving the gas pump 21 , the liquefied gas stored in the liquefied gas storage device 11 is extracted to the liquefied gas supply line 2 and sent to the heat exchanger 12 through the liquefied gas supply line 2 . The vaporized gas generated by vaporizing the liquefied gas in the heat exchanger 12 is sent to the supply destination 13 through the vaporized gas supply line 3 by the gas pump 21 .

(cold heat recovery cycle)
The cold recovery cycle 4 is configured to circulate the cold heat transfer medium under the organic Rankine cycle. The cold heat recovery cycle 4 includes a cold heat flow path 40 for circulating a cold heat medium that has exchanged heat with the liquefied gas, a cold heat turbine 5 configured to be driven by the cold energy of the cold heat medium, It includes a cooling pump 41 configured to compress the cooling heat medium, and a cooling heater 42 configured to heat the cooling heat medium compressed by the cooling pump 41 .

The other side passage 122 of the heat exchanger 12 is provided on the cold heat recovery cycle 4 and is connected to the cold heat flow path 40 so that the cold heat medium can flow therethrough. The heat exchanger 12 functions as a cooler for cold heat in the cold heat recovery cycle 4 . The cold-heat cooler (heat exchanger 12) is configured to cool the cold-heat heat medium expanded by the cold-heat turbine 5 with the cold energy of the liquefied gas.

The cold turbine 5 is provided downstream of the one side passage 421 of the cold heater 42 and upstream of the other side passage 122 of the heat exchanger 12 in the cold heat recovery cycle 4 . The cold pump 41 is provided downstream of the other side passage 122 of the heat exchanger 12 and upstream of the one side passage 421 of the cold heater 42 in the cold heat recovery cycle 4 . In addition, the “upstream side” means the upstream side in the flow direction of the heat medium (heat medium for cold and heat), and the “downstream side” means the downstream side in the flow direction of the heat medium (heat medium for cold and heat). there is

(cold heat pump)
The cold heat pump 41 is configured to send the cold heat medium to the downstream side of the cold heat recovery cycle 4 (that is, the side where the cold heat heater 42 is located). In the illustrated embodiment, the cooling pump 41 includes moving blades 411 provided in the cooling flow path 40, and an electric motor 412 configured to supply driving force for rotating the moving blades 411 to the moving blades 411. ,including. By driving the cooling pump 41 , the cooling heat medium circulates through the other side passage 122 of the heat exchanger 12 and the cooling flow path 40 . The cold heat medium cooled by the heat exchanger 12 is introduced to the cold heater 42 after being compressed by the cold heat pump 41 . The cold heat medium heated by the cold heater 42 is introduced into the cold turbine 5 . In some embodiments, the cold recovery cycle 4 is configured to liquefy the cold heat medium by cooling in the heat exchanger 12 and vaporize the cold heat medium by heating in the cold heater 42. may be

(cold heat heater)
The cold-heat heater 42 is configured to perform heat exchange between the cold-heat heat medium flowing through the cold-heat recovery cycle 4 and the external water introduced from the outside of the cold-heat recovery system 1 . The cold heater 42 includes a one side passage 421 through which the cold heat medium flows and the other side passage 422 through which the external water flows. The one-side passage 421 of the cold heater 42 is provided on the cold heat recovery cycle 4 and is connected to the cold heat flow path 40 so that the cold heat medium can flow therethrough. In the cold/heat heater 42, heat is exchanged between the one-side passage 421 and the other-side passage 422, and the thermal energy of the external water flowing through the other-side passage 422 is transferred to the cold/heat heat medium flowing through the one-side passage 421. to be recovered. As a result, the cooling/heating medium flowing through the one-side passage 421 is heated. The cold heat medium introduced into the cold turbine 5 is heated by the cold heater 42 .

The external water may be any water that can heat the object of heat exchange as a heat medium in the heat exchanger (water having a higher temperature than the object of heat exchange), and may be normal temperature water. The external water is preferably water that is easily available in the ship 10A and the floating body 10B (for example, outboard water such as seawater, engine cooling water for cooling the engine of the ship 10A, etc.).

(cooling turbine)
The cold turbine 5 includes a rotating shaft 51 , turbine blades 52 attached to the rotating shaft 51 , and a casing 53 that rotatably houses the rotating shaft 51 and the turbine blades 52 . The cooling turbine 5 is configured to rotate the turbine blades 52 with the energy of the cooling heat medium introduced into the casing 53 . The cold heat medium that has passed through the turbine blades 52 is discharged to the outside of the casing 53 .

The cold heat recovery cycle 4 is configured to recover the rotational force of the turbine blades 52 as power. In the illustrated embodiment, the cold recovery cycle 4 further includes a cold generator 54 configured to generate power by driving the cold turbine 5 . The cooling generator 54 is mechanically connected to the rotating shaft 51 and configured to convert the rotational force of the turbine blades 52 into electric power. In some other embodiments, the cold heat recovery cycle 4 does not convert the rotational force of the turbine blades 52 into electric power, but uses a power transmission device (for example, a coupling, belt, pulley, etc.) as power. may be collected. The cold heat recovery cycle 4 may also include a bypass flow path 43 that bypasses the cold turbine 5 .

(Turbine for vaporized gas)
The cold heat recovery system 1 may include a vaporized gas turbine 6 configured to be driven by the cold energy of the vaporized gas obtained by vaporizing the liquefied gas, as shown in FIG. The vaporized gas turbine 6 includes turbine blades 62 provided in the vaporized gas flow path 30 . The vaporized gas is introduced into the vaporized gas turbine 6 after being pressurized by the gas pump 21 and heated in the first heat exchanger 12 . The vaporized gas supply line 3 includes an upstream vaporized gas supply line 3A for guiding the vaporized gas from the first heat exchanger 12 to the vaporized gas turbine 6, and a vaporized gas supply line 3A from the vaporized gas turbine 6 to a gas supply destination 13. and a downstream vaporized gas supply line 3B for guiding the .

The vaporized gas turbine 6 includes a rotating shaft 61 , the above-described turbine blades 62 attached to the rotating shaft 61 , and a casing 63 that rotatably houses the rotating shaft 61 and the turbine blades 62 . The vaporized gas turbine 6 is configured to rotate the turbine blades 62 with the energy (expansion energy) of the vaporized gas introduced into the casing 63 . That is, the vaporized gas turbine 6 is an expansion turbine that uses vaporized gas as a working fluid. The vaporized gas that has passed through the turbine blades 62 is discharged outside the casing 63 .

The vaporized gas turbine 6 is configured to recover the rotational force of the turbine blades 62 as power. In the illustrated embodiment, the vaporized gas turbine 6 further includes a vaporized gas generator 64 configured to generate power by driving the turbine blades 62 . The vaporized gas generator 64 is mechanically connected to the rotating shaft 61 and configured to convert the rotational force of the turbine blades 62 into electric power. Note that in some other embodiments, the vaporized gas turbine 6 does not convert the rotational force of the turbine blades 62 into electric power, but rather uses power transmission devices (for example, couplings, belts, pulleys, etc.) to power the vaporized gas turbine 6 as it is. may be collected as Further, the vaporized gas supply line 3 may include a bypass passage 31 that bypasses the vaporized gas turbine 6 .

(heater for vaporized gas)
The cold heat recovery system 1 is configured to exchange heat between the vaporized gas flowing through the vaporized gas supply line 3 and the external water introduced from the outside of the cold heat recovery system 1, as shown in FIG. A vaporized gas heater 32 may be provided. The vaporized gas heater 32 is provided in the downstream vaporized gas supply line 3</b>B downstream of the vaporized gas turbine 6 .

The vaporized gas heater 32 includes a one side passage 321 through which the vaporized gas flows and the other side passage 322 through which external water flows. The one-side passage 321 of the vaporized gas heater 32 is provided on the vaporized gas supply line 3 and connected to the vaporized gas flow path 30 so as to allow the vaporized gas to flow therethrough. In the vaporized gas heater 32, heat is exchanged between the one side passage 321 and the other side passage 322, and the thermal energy of the external water flowing through the other side passage 322 is transferred to the vaporized gas flowing through the one side passage 321. be recovered. Thereby, the vaporized gas flowing through the one-side passage 321 is heated. By heating the vaporized gas with the vaporized gas heater 32 , the temperature of the vaporized gas can be raised to the temperature required at the gas supply destination 13 .

(Second heat exchanger)
The cold heat recovery system 1, as shown in FIG. a second heat exchanger 14 configured to exchange heat with external water. The second heat exchanger 14 is a cooling heat medium provided downstream of the cooling turbine 5 and the bypass flow path 43 and upstream of the first heat exchanger 12 in the cooling heat recovery cycle 4. includes one side passage 141 through which water flows and the other side passage 142 through which external water flows. The one-side passage 141 of the second heat exchanger 14 is provided on the cold heat recovery cycle 4 and is connected to the cold heat flow path 40 so that the cold heat medium can flow therethrough.

The cold heat medium that has passed through the cold turbine 5 or the bypass passage 43 flows through the one side passage 141 of the second heat exchanger 14 and is then guided to the other side passage 122 of the first heat exchanger 12 . In the second heat exchanger 14 , heat is exchanged between the one-side passage 141 and the other-side passage 142 , and the thermal energy of the external water flowing through the other-side passage 142 is transferred to the cold-heat heat energy flowing through the one-side passage 141 . It is recovered in the heat medium. As a result, the cooling/heating medium flowing through the one-side passage 141 is heated. The second heat exchanger 14 raises the temperature of the cold heat medium introduced into the other side passage 122 of the first heat exchanger 12 .

(external water supply line, external water discharge line)
The cold heat recovery system 1 includes heat exchangers (the second heat exchanger 14, the cold heat heater 42, the vaporized gas heater 32) that use the external water of the cold heat recovery system 1 as a heat medium from the external water supply source 16. an external water supply line 8 for supplying external water to the external water discharge line 9 for discharging the external water discharged from the heat exchanger using the external water as a heat medium to the external water discharge destination 17; Prepare.

As shown in FIG. 1, the external water supply line 8 includes a first external water supply channel 81 connecting the external water supply source 16 and the second heat exchanger, a second external water supply channel 82 connecting the heater 42 for the gas, a third external water supply channel 83 connecting the external water supply source 16 and the vaporized gas heater 32, and the external water supply line 8 an external water pump 84 configured to deliver external water to the downstream side of (i.e., the side where the heat exchanger using external water as a heat medium is located). In the illustrated embodiment, the first external water supply channel 81 , the second external water supply channel 82 and the third external water supply channel 83 are connected to the shared channel 86 upstream of the branch 85 . It's becoming The external water pump 84 includes rotor blades 841 provided in the shared flow path 86 and an electric motor 842 configured to supply driving force to the rotor blades 841 to rotate the rotor blades 841 . By driving the external water pump 84, the external water is extracted from the external water supply source 16 to the external water supply line 8, and passed through the external water supply line 8 to the heat exchanger using the external water as a heat medium. Sent. By providing the external water pump 84 in the shared flow path 86, the cold heat recovery system 1 can be prevented from becoming larger, more complex, and more expensive. In some other embodiments, the external water supply line 8 may be configured without the shared flow path 86, and the first external water supply flow path 81 and the second external water supply flow path 82 and third external water supply channels 83 may be connected to different external water supply sources 16 .

As shown in FIG. 1, the external water discharge line 9 includes a first external water discharge flow path 91 connecting the second heat exchanger 14 and the external water discharge destination 17A (17), and a cold/heat heater. 42 and the external water discharge destination 17B, and a third external water discharge flow channel 93 connecting the vaporized gas heater 32 and the external water discharge destination 17C. include. The external water discharge destination 17A may be the same as at least one of the discharge destinations 17B and 17C. Also, the first external water discharge channel 91 may be configured to share a part with at least one of the second external water discharge channel 92 or the third external water discharge channel 93 .

(Cold heat recovery cycle according to comparative example)
FIG. 2 is a schematic configuration diagram schematically showing the configuration of a ship or floating body provided with a cold energy recovery system according to a comparative example. The cold heat recovery system 01 according to the comparative example includes a third heat exchanger 15 instead of the second heat exchanger 14 described above. The cold heat recovery system 01 includes the first heat exchanger 12 described above, the liquefied gas supply line 2 described above, the vaporized gas supply line 3 described above, and the cold heat recovery cycle 4 including the cold turbine 5 described above. , and the vaporized gas turbine 6 described above.

The third heat exchanger 15 is provided in the upstream vaporized gas supply line 3</b>A upstream of the vaporized gas turbine 6 . The third heat exchanger 15 is configured to exchange heat between the vaporized gas flowing through the upstream vaporized gas supply line 3A and external water introduced from outside the cold heat recovery system 1 . The third heat exchanger 15 includes one side passage 151 through which vaporized gas flows and the other side passage 152 through which external water flows. The one side passage 151 of the third heat exchanger 15 is provided on the upstream vaporized gas supply line 3A and is connected to the vaporized gas flow path 30 so as to allow the vaporized gas to flow therethrough. In the third heat exchanger 15, heat is exchanged between the one-side passage 151 and the other-side passage 152, and the thermal energy of the external water flowing through the other-side passage 152 is transferred to the vaporized gas flowing through the one-side passage 151. to be recovered. Thereby, the vaporized gas flowing through the one-side passage 151 is heated. By heating the vaporized gas with the third heat exchanger 15, the temperature of the vaporized gas at the inlet of the vaporized gas turbine 6 can be increased.

A cold heat recovery system 01 according to the comparative example includes an external water supply line 08 and an external water discharge line 09 . The external water supply line 08 includes a fourth external water supply channel 87 connecting the external water supply source 16 and the third heat exchanger 15, the second external water supply channel 82 described above, and the It includes a third external water supply channel 83 and the external water pump 84 described above. The external water discharge line 09 includes the fourth external water discharge channel 94 connecting the third heat exchanger 15 and the external water discharge destination 17D, the second external water discharge channel 92 described above, and the and a third external water discharge channel 93 .

In the cold heat recovery system 1 shown in FIG. 1, the heat medium for cold heat is heated by the second heat exchanger 14, so compared to the cold heat recovery system 01 according to the comparative example, the cold heat supply to the first heat exchanger 12 The temperature of the cooling/heating medium to be applied is increased. By increasing the height of the cold heat medium supplied to the first heat exchanger 12, the amount of heat exchanged between the liquefied gas and the cold heat medium in the first heat exchanger 12 can be increased. As a result, in the cold heat recovery system 1 shown in FIG. 1, the temperature of the vaporized gas at the outlet of the first heat exchanger 12 is higher than in the cold heat recovery system 01 according to the comparative example.

A cold heat recovery system 1 according to some embodiments, as shown in FIG. It comprises a recovery cycle 4 and a second heat exchanger 14 as described above.

According to the above configuration, the second heat exchanger 14 allows the cold heat medium flowing between the cold heat turbine 5 and the first heat exchanger 12 in the cold heat recovery cycle 4 to flow between the external water and the cold heat medium. Heat exchange is performed to heat the cooling/heating medium. Therefore, the temperature of the cold heat medium supplied to the first heat exchanger 12 is higher than that of the cold heat recovery system 01 according to the comparative example. The first heat exchanger 12 heats the liquefied gas by exchanging heat between the cooling/heating medium heated by the second heat exchanger 14 and the liquefied gas. By preheating the cold heat medium guided to the first heat exchanger 12 by the second heat exchanger 14, the cold heat in the first heat exchanger 12 is reduced compared to the cold heat recovery system 01 according to the comparative example. It is possible to increase the amount of heat exchange between the heat medium for cooling and the liquefied gas, and increase the cold energy recovered from the liquefied gas by the heat medium for cold. As a result, the output of the cold turbine 5 can be increased, and thus the output of the cold heat recovery system 1 can be increased.

In addition, by preheating the cold heat medium guided to the first heat exchanger 12 by the second heat exchanger 14, the heat medium for cold heat in the first heat exchanger 12 and the liquefied gas It is possible to suppress solidification of the cooling/heating medium during heat exchange. As a result, compared to the cold heat recovery system 01 according to the comparative example, it is possible to prevent the cold heat medium solidified in the first heat exchanger 12 from freezing and clogging the first heat exchanger 12 . Therefore, it is possible to improve the reliability of the cold heat recovery system 1 when using a small heat exchanger as the first heat exchanger 12 .

In some embodiments, the cold recovery system 1 described above includes a liquefied gas supply line 2, a cold recovery cycle 4, a first heat exchanger 12 and a second heat exchanger 14, as shown in FIG. In addition, the above-described vaporized gas supply line 3 (upstream vaporized gas supply line 3A) and the above-described vaporized gas turbine 6 are further provided.

According to the above configuration, the vaporized gas is supplied from the first heat exchanger 12 to the vaporized gas turbine 6 through the vaporized gas supply line 3 (the upstream vaporized gas supply line 3A). By preheating the cold heat medium guided to the first heat exchanger 12 by the second heat exchanger 14, heat exchange between the cold heat medium and the liquefied gas in the first heat exchanger 12 The amount can be increased, and the cold energy recovered from the liquefied gas by the cold heat transfer medium can be increased. As a result, the temperature of the vaporized gas at the inlet of the vaporized gas turbine 6 can be increased, so that the output of the vaporized gas turbine 6 can be increased, and the output of the cold heat recovery system 1 can be increased.

The output generated by the cold energy recovery system 1 shown in FIG. It is expressed by subtracting the total power consumption of one pump (the gas pump 21, the cold/heat pump 41, and the external water pump 84). The cold energy recovery system 1 can increase the electric power generated by the cold energy generator 54 and the vaporized gas generator 64 compared to the cold energy recovery system 01 according to the comparative example. Therefore, the output generated by the cold energy recovery system 1 is greater than the output generated by the cold energy recovery system 01 according to the comparative example.

Further, since the temperature of the vaporized gas at the inlet of the vaporized gas turbine 6 can be increased by the first heat exchanger 12 and the second heat exchanger 14, the vaporized gas supplied to the vaporized gas turbine 6 can be heated in advance. It is not necessary to provide a heat exchanger (the third heat exchanger 15 shown in FIG. 2) to the upstream vaporized gas supply line 3A. In this case, the reliability of the cold heat recovery system 1 can be improved because the risk of blockage of the heat exchanger is eliminated.

In some embodiments, the external water in the cold recovery system 1 described above comprises seawater. In the illustrated embodiment, as shown in FIG. 1, the external water supply source 16 consists of a water intake for introducing outboard water (such as seawater) provided in the vessel 10A or the floating body 10B. The external water discharge destinations 17 (17A, 17B, 17C, 17D) consist of discharge ports provided in the ship 10A or the floating body 10B for discharging water outboard.

According to the above configuration, since the cold energy recovery system 1 is mounted on the ship 10A, the floating body 10B, or the like, it is easy to obtain seawater. The cold heat recovery system 1 utilizes readily available seawater as a heat medium for cold heat medium in heat exchangers such as the second heat exchanger 14 and the cold heater 42, thereby recovering the heat of the cold heat medium. Since there is no need to provide a storage facility for storing the medium, it is possible to prevent the cold energy recovery system 1 from becoming larger, more complicated, and more expensive.

FIG. 3 is a schematic configuration diagram schematically showing the configuration of a vessel or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure.
In some embodiments, as shown in FIG. 3 , the cold recovery system 1 described above further comprises a heat carrier make-up line 24 branching from the liquefied gas supply line 2 and connected to the cold recovery cycle 4 . In the illustrated embodiment, the heat medium replenishing line 24 has one side 251 connected downstream of the gas pump 21 to the liquefied gas supply line 2 and is connected to the first heat exchanger 12 in the cold heat recovery cycle 4 . and a valve 26 configured to open and close the replenishment channel 25 .

In the illustrated embodiment, the cooling heat recovery cycle 4 supplies a cold heat medium (liquefied gas in the illustrated example) downstream of the connection of the heat medium replenishment line 24 and upstream of the cold pump 41 . A storage device 44 is included for storage. The cold heat recovery system 1 includes a liquid height acquisition device 71 configured to acquire the liquid height of the cold heat medium stored in the storage device 44, and the liquid height acquired by the liquid height acquisition device 71. and an opening/closing control device 72 for controlling the opening/closing of the valve 26 accordingly. For example, the opening/closing control device 72 instructs the valve 26 to close the replenishment channel 25 when the liquid height of the cooling/heating medium acquired by the liquid height acquisition device 71 is equal to or higher than a threshold value. During the operation of the cold energy recovery cycle 4, the cold heat medium in the storage device 44 may decrease due to leakage to the outside of the cold energy recovery cycle 4, for example. The opening/closing control device 72 instructs the valve 26 to open the replenishment flow path 25 when the liquid height of the cooling/heating heat medium acquired by the liquid height acquisition device 71 becomes less than the threshold value. When the valve 26 is opened, the pressure difference between the liquefied gas supply line 2 to which the heat medium replenishment line 24 is connected and the cold heat recovery cycle 4 causes the liquefied gas supply line 2 to liquefy into the cold heat recovery cycle 4 through the replenishment passage 25. gas is delivered.

According to the above configuration, the liquefied gas can be introduced from the liquefied gas supply line 2 to the cold energy recovery cycle 4 as a heat medium for cold energy through the heat medium supplement line 24 connecting the liquefied gas supply line 2 and the cold energy recovery cycle 4. be possible. In this case, it becomes easier to replenish the cooling/heating medium than when the cooling/heating medium is other than the liquefied gas. In addition, since there is no need to separately provide a storage facility for the cold heat medium for replenishment, the cold heat recovery system 1 can be prevented from becoming larger, more complex, and more expensive. In addition, by using a liquefied gas with a low freezing point as the cold heat medium, the lowest temperature of the cold heat medium in the cold heat recovery cycle 4 can be lowered, so the performance of the cold heat recovery cycle 4 can be improved. By using a liquefied gas, which has a smaller specific volume than propane gas, as a heat medium for cold heat, the amount of circulation in the cold heat recovery cycle 4 can be reduced. I can plan. As a result, it is possible to suppress an increase in the size and price of the cold energy recovery system 1 .

In some embodiments, as shown in FIG. 3, the cold recovery cycle 4 of the cold recovery system 1 described above includes the cold pump 41 described above for delivering the cold heat transfer medium. The cooling pump 41 is configured to pressurize at least part of the cooling heat medium (liquefied gas) to a supercritical state. In the illustrated embodiment, on the downstream side of the first heat exchanger 12 in the cold heat recovery cycle 4 and on the upstream side of the cold heat pump 41, the cold heat medium (liquefied gas) becomes a high-pressure liquid. there is At least part of the cooling heat medium supplied to the cooling turbine 5 is in a supercritical state by being pressurized by the cooling pump 41 .

According to the above configuration, at least part of the cooling heat medium can be pressurized to a supercritical state by the cooling pump 41 . In this case, the volume density of the cold heat medium can be increased by making the heat medium for cold heat supercritical, so that the equipment of the cold heat recovery cycle 4 such as the turbine 5 for cold heat can be made smaller. As a result, it is possible to suppress an increase in the size and price of the cold energy recovery system 1 .

Note that the heat medium replenishing line 24 described above can be applied to cold energy recovery systems other than the cold energy recovery system 1 shown in FIG. FIG. 4 is a schematic configuration diagram schematically showing the configuration of a vessel or floating body provided with a cold energy recovery system according to an embodiment of the present disclosure.
As shown in FIG. 4, a cold heat recovery system 1A according to some embodiments includes the above-described first heat exchanger 12 and the above-described third heat The exchanger 15, the above-described liquefied gas supply line 2, the above-described vaporized gas supply line 3, the cold heat recovery cycle 4 including the above-described cold heat turbine 5, the above-described vaporized gas turbine 6, and the above-described external water It comprises a supply line 08 and an external water discharge line 09 as described above. In addition, the cold energy recovery system 1A further includes the heat medium replenishment line 24 described above.

In some other embodiments, the cold heat recovery system 1, 1A does not include the heat medium replenishment line 24 described above, and the heat medium for cold heat circulating in the cold heat recovery cycle 4 is liquefied gas (liquefied natural gas , liquefied petroleum gas, liquid hydrogen, etc.).

A ship 10A or a floating body 10B according to some embodiments is provided with the cold energy recovery system 1 described above, as shown in FIGS. According to the above configuration, by improving the output and reliability of the cold energy recovery system 1, the output and reliability of the vessel 10A and the floating body 10B provided with the cold energy recovery system 1 can be improved.

The present disclosure is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

The contents described in the several embodiments described above are understood as follows, for example.

1) A cold energy recovery system (1) according to at least one embodiment of the present disclosure,
A cold heat recovery system (1) installed in a ship (10A) or a floating body (10B) having a liquefied gas storage device (11) configured to store liquefied gas,
a first heat exchanger (12) configured to vaporize the liquefied gas;
a liquefied gas supply line (2) for supplying the liquefied gas from the liquefied gas storage device (11) to the first heat exchanger (12);
A cold heat recovery cycle (4) configured to circulate a cold heat medium heat-exchanged with the liquefied gas in the first heat exchanger (12), and driven by the cold heat medium. a cold recovery cycle (4) comprising a cold turbine (5) configured to
The cold heat medium flowing between the cold turbine (5) and the first heat exchanger (12) in the cold heat recovery cycle (4) and the cold heat recovery system (1) introduced from outside a second heat exchanger (14) configured to exchange heat with external water.

According to the above configuration 1), the second heat exchanger (14) allows the cold heat to flow between the cold heat turbine (5) and the first heat exchanger (12) in the cold heat recovery cycle (4). Heat is exchanged between the heat medium and the external water to heat the cold heat medium. The first heat exchanger (12) heats the liquefied gas by exchanging heat between the cooling/heating medium heated by the second heat exchanger (14) and the liquefied gas. By preheating the cold heat medium to be guided to the first heat exchanger (12) in the second heat exchanger (14), the cold heat medium and the liquefied gas in the first heat exchanger (12) It is possible to increase the amount of heat exchanged between and, and increase the cold energy recovered from the liquefied gas by the heat medium for cold heat. As a result, the output of the cold turbine (5) can be increased, and the output of the cold heat recovery system (1) can be increased.

In addition, by preheating the cold heat medium to be guided to the first heat exchanger (12) in the second heat exchanger (14), the heat medium for cold heat in the first heat exchanger (12) It is possible to suppress solidification of the cold heat medium during heat exchange with the liquefied gas. As a result, it is possible to prevent the cold heat medium solidified in the first heat exchanger (12) from freezing and clogging the first heat exchanger (12). Therefore, the reliability of the cold heat recovery system (1) can be improved when a small heat exchanger is used as the first heat exchanger (12).

2) In some embodiments, the cold energy recovery system (1) of 1) above,
A heating medium replenishment line (24) branched from the liquefied gas supply line (2) and connected to the cold heat recovery cycle (4) is further provided.

According to the configuration 2) above, the cold heat recovery cycle (4) is supplied from the liquefied gas supply line (2) through the heat medium replenishment line (24) connecting the liquefied gas supply line (2) and the cold heat recovery cycle (4). It becomes possible to guide the liquefied gas, which is a heat carrier, to the In this case, it becomes easier to replenish the cooling/heating medium than when the cooling/heating medium is other than the liquefied gas. In addition, since there is no need to separately provide a storage facility for the cold heat medium for replenishment, it is possible to prevent the cold heat recovery system (1) from becoming larger, more complex, and more expensive. In addition, by using a liquefied gas with a low freezing point as the cold heat transfer medium, the minimum temperature of the cold heat transfer medium in the cold heat recovery cycle (4) can be lowered, thereby improving the performance of the cold heat recovery cycle (4). can be done. By using a liquefied gas with a smaller specific volume than propane gas or the like as a heat medium for cold heat, the amount of circulation in the cold heat recovery cycle (4) can be reduced, so the cold heat recovery cycle (4) such as a cold turbine (5) can be used. equipment can be made smaller. As a result, it is possible to suppress an increase in the size and price of the cold energy recovery system (1).

3) In some embodiments, the cold energy recovery system (1) of 2) above,
The cold heat recovery cycle (4) is a cold heat pump (41) for sending the cold heat medium, and is configured to pressurize at least part of the cold heat medium to a supercritical state. including a pump (41) for

According to the above configuration 3), at least part of the cooling heat medium can be pressurized to a supercritical state by the cooling pump (41). In this case, by making the heat medium for cold heat supercritical, the volume density of the heat medium for cold heat can be increased. I can plan. As a result, it is possible to suppress an increase in the size and price of the cold energy recovery system (1).

4) In some embodiments, the cold energy recovery system (1) according to any one of 1) to 3) above,
a vaporized gas turbine (6) configured to be driven by the vaporized gas obtained by vaporizing the liquefied gas;
It further comprises a vaporized gas supply line (upstream vaporized gas supply line 3A) for supplying the vaporized gas from the first heat exchanger (12) to the vaporized gas turbine (6).

According to the above configuration 4), the vaporized gas is supplied from the first heat exchanger (12) to the vaporized gas turbine (6) through the vaporized gas supply line (3A). By preheating the cold heat medium to be guided to the first heat exchanger (12) in the second heat exchanger (14), the cold heat medium and the liquefied gas in the first heat exchanger (12) It is possible to increase the amount of heat exchanged between and, and increase the cold energy recovered from the liquefied gas by the heat medium for cold heat. As a result, the temperature of the vaporized gas at the inlet of the vaporized gas turbine (6) can be increased, so that the output of the vaporized gas turbine (6) can be increased, which in turn increases the output of the cold heat recovery system (1). be able to. Further, since the temperature of the vaporized gas at the inlet of the vaporized gas turbine (6) can be increased by the first heat exchanger (12) and the second heat exchanger (14), the vaporized gas turbine (6) It is not necessary to provide a heat exchanger for preheating the supplied vaporized gas in the vaporized gas supply line (3A). In this case, the reliability of the cold heat recovery system (1) can be improved because the risk of blockage of the heat exchanger is eliminated.

5) In some embodiments, the cold energy recovery system (1) according to any one of 1) to 4) above,
The external water includes seawater.

According to the configuration of 5) above, since the cold energy recovery system (1) is mounted on the ship (10A), the floating body (10B), or the like, it is easy to obtain seawater. The cold heat recovery system (1) utilizes readily available seawater as the heat medium for the heat medium for cold heat in the first heat exchanger (12), and is a storage facility or the like that stores the heat medium for the heat medium for cold heat. Since it is not necessary to provide the cold energy recovery system (1), it is possible to suppress the increase in size, complexity, and price of the cold energy recovery system (1).

6) The ship (10A) or floating body (10B) according to at least one embodiment of the present disclosure,
A cold energy recovery system (1) according to any one of 1) to 5) above is provided.

According to the configuration of 6) above, by improving the output and reliability of the cold energy recovery system (1), the output and reliability of the ship (10A) and the floating body (10B) equipped with the cold energy recovery system (1) are improved. can improve.

1, 1A cold heat recovery system 01 cold heat recovery system according to comparative example 2 liquefied gas supply line 3 vaporized gas supply line 3A upstream vaporized gas supply line 3B downstream vaporized gas supply line 4 cold heat recovery cycle 5 cold heat turbine 6 for vaporized gas Turbines 8, 08 External water supply lines 9, 09 External water discharge line 10A Ship 10B Floating body 11 Liquefied gas storage device 12 First heat exchanger 13 Gas destination 14 Second heat exchanger 15 Third heat exchanger 16 External water supply sources 17, 17A to 17D External water discharge destination 20 Liquefied gas flow path 21 Gas pump 24 Heat medium replenishment line 26 Valve 30 Vaporized gas flow path 32 Vaporized gas heater 40 Cooling flow path 41 Cooling pump 42 for cold heat heater 44 storage device 51, 61 rotating shaft 52, 62 turbine blade 53, 63 casing 54, 64 generator 71 liquid height acquisition device 72 open/close control device 84 external water pump

Claims (6)

A cold heat recovery system installed in a ship or floating body having a liquefied gas storage device configured to store liquefied gas,
a first heat exchanger configured to vaporize the liquefied gas;
a liquefied gas supply line for supplying the liquefied gas from the liquefied gas storage device to the first heat exchanger;
A cold heat recovery cycle configured to circulate a cold heat medium heat-exchanged with the liquefied gas in the first heat exchanger, wherein the cold heat recovery cycle is configured to be driven by the cold heat medium. a cold recovery cycle including a turbine for
Heat exchange is performed between the cold heat medium flowing between the cold heat turbine and the first heat exchanger in the cold heat recovery cycle and external water introduced from the outside of the cold heat recovery system. a second heat exchanger configured to
Cold heat recovery system. Further comprising a heat medium replenishment line branched from the liquefied gas supply line and connected to the cold heat recovery cycle,
The cold heat recovery system according to claim 1 . The cold recovery cycle includes a cold pump for sending the cold heat medium, the cold heat pump configured to pressurize at least part of the cold heat medium to a supercritical state,
The cold heat recovery system according to claim 2. a vaporized gas turbine configured to be driven by the vaporized gas obtained by vaporizing the liquefied gas;
a vaporized gas supply line for supplying the vaporized gas from the first heat exchanger to the vaporized gas turbine,
The cold heat recovery system according to any one of claims 1 to 3. wherein the external water comprises seawater;
The cold heat recovery system according to any one of claims 1 to 4. Equipped with the cold heat recovery system according to any one of claims 1 to 5,
vessels or floating bodies;

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