Turbines for heat and cold power generation

Abstract

A turbine for cold and hot power generation is provided in a heat medium circulation circuit configured to circulate a heat medium for heating liquefied gas, and comprises: a rotor shaft, a casing accommodating the rotor shaft, at least one moving blade arranged around the rotor shaft, at least one stationary blade supported by the casing, a mechanical seal for sealing between the rotor shaft and the casing on the upstream side compared with the at least one moving blade, and a pressure reducing circuit, one side of the pressure reducing circuit is connected to a sealed space, and the other side is connected to a low-pressure portion in the heat medium circulation circuit where the pressure is lower than that in the sealed space, the sealed space is formed inside the casing due to the configuration of the mechanical seal, and can allow the heat medium leaking from between the at least one stationary blade and the at least one moving blade to flow in.

Description

Technical Field

[0001] The present invention relates to a turbine for cold-heat power generation provided in a heat medium circulation circuit configured as a heat medium circulation circuit for heating liquefied gas.

[0002] This application claims priority based on Japanese Patent Application No. 2020-119695 filed with the Japan Patent Office on July 13, 2020, the contents of which are cited here. Background Art

[0003] Liquefied gas (e.g., liquefied natural gas) is liquefied for the purpose of transportation and storage, and when supplied to a supply target such as a city gas or a thermal power plant, it is heated by a heat medium such as seawater and gasified. When the liquefied gas is gasified, sometimes the cold and heat energy is not discharged to the seawater, but is recovered as electric power for cold and heat power generation (e.g., Patent Document 1).

[0004] As a heat and cold power generation cycle using liquefied natural gas, a secondary medium Rankine cycle is known (for example, Patent Document 1). The secondary medium Rankine cycle is a method in which a secondary medium circulating in a closed loop is heated in an evaporator using seawater as a heat source to evaporate, the vapor is introduced into a turbine for heat and cold power generation to obtain power, and then cooled and condensed using liquefied natural gas.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Utility Model Publication No. 61-59803

[0008] Technical problem to be solved by the invention

[0009] In turbines for cold and hot power generation, a mechanical seal is sometimes used for a shaft seal structure for sealing between a turbine shaft and a housing that accommodates the turbine shaft in order to suppress external leakage of a secondary medium (e.g., Patent Document 1). By configuring a mechanical seal, a sealed space is formed between the turbine shaft and the housing into which a secondary medium leaking from between the stationary blades and the moving blades can flow. The sealed space becomes higher than atmospheric pressure due to the thermal medium leaking from between the stationary blades and the moving blades. For example, at startup or at partial load of the turbine, the pressure in the sealed space may become a high pressure exceeding 1 MPa. When the pressure difference between the sealed space side of the mechanical seal and the atmospheric side on the opposite side of the sealed space side is large, the pressure load applied to the mechanical seal becomes larger, and therefore, there is a concern that the risk of deterioration, damage, and leakage of the mechanical seal increases.

[0010] As strategies for ensuring the reliability of the turbine, there are the following methods: reducing the pressure load on the mechanical seal by increasing the pressure of the sealing oil supplied to the mechanical seal through a device for increasing the pressure of the sealing oil, and reducing the pressure in the sealed space in stages by providing the mechanical seal with a multiple structure (e.g., double or triple). These strategies may increase the price of the turbine for cold and hot power generation having a shaft seal structure. Summary of the invention

[0011] In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a turbine for cold / thermal power generation that can suppress an increase in the price of the turbine for cold / thermal power generation and improve the reliability of the turbine for cold / thermal power generation.

[0012] Technical means for solving technical problems

[0013] The turbine for cold and heat power generation of the present invention is provided in a heat medium circulation circuit configured to circulate a heat medium for heating liquefied gas, and comprises:

[0014] Rotor shaft;

[0015] a housing that accommodates the rotor shaft;

[0016] at least one moving blade disposed around the rotor shaft;

[0017] at least one stationary blade supported by the housing;

[0018] a mechanical seal that seals between the rotor shaft and the housing on an upstream side relative to the at least one moving blade; and

[0019] A pressure reducing line, one side of which is connected to the sealed space, and the other side of which is connected to a low-pressure portion in the heat medium circulation line where the pressure is lower than that of the sealed space, the sealed space being formed inside the shell due to the configuration of the mechanical seal and capable of allowing the heat medium leaking from between the at least one stationary blade and the at least one moving blade to flow in.

[0020] Effects of the Invention

[0021] According to at least one embodiment of the present invention, it is possible to provide a turbine for cold / thermal power generation that can suppress an increase in the price of the turbine for cold / thermal power generation and improve the reliability of the turbine for cold / thermal power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a schematic configuration diagram schematically showing the configuration of a cold-heat power generation system including a cold-heat power generation turbine according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention.

[0024] Figure 3 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, multiple embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described or shown in the drawings as embodiments are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0027] For example, expressions such as "toward a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" indicating relative or absolute configuration do not mean that the configuration is strictly so configured, but also indicate a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.

[0028] For example, expressions such as “same”, “equal” and “uniform” indicating a state in which things are equal do not necessarily mean a state in which things are strictly equal, but rather indicate a state in which there is a tolerance or a difference to the extent that the same function can be obtained.

[0029] For example, expressions indicating shapes such as a quadrilateral and a cylinder not only indicate shapes such as a quadrilateral and a cylinder in a geometrically strict sense, but also indicate shapes including concave and convex portions, chamfered portions, and the like within a range that can produce the same effect.

[0030] On the other hand, the expression “having”, “including” or “having” a constituent element is not an exclusive expression that excludes the existence of other constituent elements.

[0031] In addition, the same symbols are attached to the same structures and the description thereof may be omitted.

[0032] (Cold and heat power generation system)

[0033] Figure 1 This is a schematic configuration diagram schematically showing the configuration of a cold-heat power generation system including a cold-heat power generation turbine according to an embodiment of the present invention.

[0034] like Figure 1 As shown, the cold and heat power generation system 1 includes a turbine 2 for cold and heat power generation (hereinafter referred to as turbine 2), a liquefied gas supply line 3, a heat medium circulation line 4, a heating water supply line 5, a generator 11, a first heat exchanger 12, and a second heat exchanger 13. The liquefied gas supply line 3, the heat medium circulation line 4, and the heating water supply line 5 each include a flow path such as a pipe for fluid to flow.

[0035] The liquefied gas supply line 3 is configured to deliver liquefied gas from a liquefied gas storage device 31. The liquefied gas storage device (for example, a liquefied gas tank) 31 is configured to store liquefied gas in a liquid state.

[0036] The heat medium circulation circuit 4 is configured to circulate a heat medium having a lower freezing point than water. In the following, liquefied natural gas (LNG) is cited as a specific example of liquefied gas, and propane is cited as a specific example of the heat medium flowing in the heat medium circulation circuit 4. However, the present invention can also be applied to liquefied gases (liquid hydrogen, etc.) other than liquefied natural gas, and can also be applied to the case where a heat medium other than propane is used as the heat medium flowing in the heat medium circulation circuit 4.

[0037] In the illustrated embodiment, the cold and heat power generation system 1 further includes a liquefied gas pump 32 provided in the liquefied gas supply line 3 and a heat medium circulation pump 41 provided in the heat medium circulation line 4. One end side 33 of the liquefied gas supply line 3 is connected to the liquefied gas storage device 31, and the other end side 34 is connected to a liquefied gas equipment 35 provided outside the cold and heat power generation system 1. Examples of the liquefied gas equipment 35 include, for example, a gas tank provided on land, a gas pipe connected thereto, and the like.

[0038] By driving the liquefied gas pump 32 , the liquefied gas stored in the liquefied gas storage device 31 is sent to the liquefied gas supply line 3 , and after the liquefied gas flows from the upstream side to the downstream side in the liquefied gas supply line 3 , it is sent to the equipment 35 for liquefied gas.

[0039] The heat medium is circulated in the heat medium circulation line 4 by driving the circulation pump 41 for the heat medium. The turbine 2 is provided in the heat medium circulation line 4, and the heat medium circulation line 4 is configured to circulate the heat medium for heating the liquefied gas. The turbine 2 includes a rotor shaft 21, and is configured to be driven (rotated) by the heat medium flowing in the heat medium circulation line 4. The generator 11 is connected to the rotor shaft 21, and is configured to generate electricity using the driving force of the turbine 2 (rotational force of the rotor shaft 21) as a driving source.

[0040] The heating water supply line 5 is configured to convey heating water introduced from outside the cold and hot power generation system 1. "Heating water" may be water at room temperature as long as it is used as a heat medium in a heat exchanger to heat the object of heat exchange. In the case where the cold and hot power generation system 1 is mounted on a ship 10 or a floating body floating on the water, the heating water is preferably water that is easily available in the ship or the floating body (for example, seawater or other off-board water, cooling water for cooling the ship's engine, etc.). In one embodiment, the cold and hot power generation system 1 and the turbine 2 for cold and hot power generation are mounted on Figure 1 In another embodiment, the cold and heat power generation system 1 and the cold and heat power generation turbine 2 are installed on land.

[0041] In the illustrated embodiment, the cold and heat power generation system 1 further includes: an intermediate heat medium circulation circuit 6 configured to circulate an intermediate heat medium having a lower freezing point than water, a circulation pump 61 for the intermediate heat medium arranged in the intermediate heat medium circulation circuit 6, a heating water pump 51 arranged in the heating water supply circuit 5, and a third heat exchanger 14.

[0042] In the illustrated embodiment, the cold and heat power generation system 1 drives the circulation pump 61 for the intermediate heat medium to circulate the intermediate heat medium in the intermediate heat medium circulation line 6. One end side 52 of the heating water supply line 5 is connected to the heating water supply source 15 provided outside the cold and heat power generation system 1, and the other end side 53 is connected to the heating water discharge destination 16 provided outside the cold and heat power generation system 1. By driving the heating water pump 51, the heating water is transported from the heating water supply source 15 to the heating water supply line 5, and the heating water is sent to the heating water discharge destination 16 after flowing from the upstream side to the downstream side of the heating water supply line 5.

[0043] When the cold and heat power generation system 1 is mounted on the hull 10 or a floating body floating on the water, the supply source 15 of the heating water may include, for example, a water intake 15A provided on the hull 10 for introducing water from outside the ship. In addition, when the cold and heat power generation system 1 is mounted on the hull 10 or a floating body, the discharge destination 16 of the heating water may include, for example, a discharge port 16A provided on the hull 10 for discharging water to outside the ship.

[0044] The intermediate heat medium may be the same type of heat medium as or a different type of heat medium flowing in the heat medium circulation line 4. In the illustrated embodiment, the intermediate heat medium is composed of propane, and the heating water is composed of seawater obtained from outside the ship.

[0045] The first heat exchanger 12 is configured to perform heat exchange between the liquefied gas flowing in the liquefied gas supply line 3 and the heat medium flowing in the heat medium circulation line 4 .

[0046] exist Figure 1 In the illustrated embodiment, the first heat exchanger 12 includes a liquefied gas flow path 121 provided in the liquefied gas supply line 3 and through which the liquefied gas flows, and a heat medium flow path 122 provided in the heat medium circulation line 4 and through which the heat medium flows. Heat exchange is performed between the heat medium in the heat medium flow path 122 and the liquefied gas in the liquefied gas flow path 121.

[0047] The second heat exchanger 13 is configured to perform heat exchange between the heat medium flowing through the heat medium circulation line 4 and the intermediate heat medium flowing through the intermediate heat medium circulation line 6 .

[0048] exist Figure 1 In the illustrated embodiment, the second heat exchanger 13 includes a heat medium flow path 131 provided in the heat medium circulation line 4 and through which the heat medium flows, and an intermediate heat medium flow path 132 provided in the intermediate heat medium circulation line 6 and through which the intermediate heat medium flows. Heat exchange is performed between the intermediate heat medium in the intermediate heat medium flow path 132 and the heat medium in the heat medium flow path 131.

[0049] In addition, in other embodiments, the second heat exchanger 13 may also be configured to perform heat exchange between a heat medium and heating water, the heat medium flowing in the heat medium circulation line 4, and the heating water flowing in the heating water supply line 5. The second heat exchanger 13 may also include a heating water flow path provided in the heating water supply line 5 and through which heating water flows, and the heating water flow path is used to perform heat exchange with the heat medium flow path 132. In this case, the cold and heat power generation system 1 does not need to include the intermediate heat medium circulation line 6 and the third heat exchanger 14, so that the structure can be suppressed from being large-scale and complicated.

[0050] The third heat exchanger 14 is configured to perform heat exchange between the intermediate heat medium flowing through the intermediate heat medium circulation line 6 and the heating water flowing through the heating water supply line 5 .

[0051] exist Figure 1 In the embodiment shown, the third heat exchanger 14 includes an intermediate heat medium flow path 141 provided in the intermediate heat medium circulation line 6 and through which the intermediate heat medium flows, and a heating water flow path 142 provided in the heating water supply line 5 and through which the heating water flows. Heat exchange is performed between the intermediate heat medium in the intermediate heat medium flow path 141 and the heating water in the heating water flow path 142.

[0052] The first heat exchanger 12 (specifically, the liquefied gas flow path 121) is provided on the downstream side of the liquefied gas pump 32 of the liquefied gas supply line 3 and on the upstream side of the liquefied gas equipment 35. The liquefied gas pump 32 is provided on the downstream side of the liquefied gas storage device 31 of the liquefied gas supply line 3. In addition, the first heat exchanger 12 (specifically, the heat medium flow path 122) is provided on the downstream side of the turbine 2 of the heat medium circulation line 4 and on the upstream side of the heat medium circulation pump 41.

[0053] The second heat exchanger 13 (specifically, the heat medium flow path 131) is provided on the downstream side of the heat medium circulation pump 41 of the heat medium circulation line 4 and on the upstream side of the turbine 2. In addition, the second heat exchanger 13 (specifically, the intermediate heat medium flow path 132) is provided on the downstream side of the third heat exchanger 14 (specifically, the intermediate heat medium flow path 141) of the intermediate heat medium circulation line 6 and on the upstream side of the intermediate heat medium circulation pump 61.

[0054] The third heat exchanger 14 (specifically, the heating water flow path 142) is provided downstream of the heating water pump 51 of the heating water supply line 5 and upstream of the heating water discharge destination 16. The heating water pump 51 is provided downstream of the heating water supply source 15 of the heating water supply line 5.

[0055] The liquefied gas in a liquid state after being pressurized by the liquefied gas pump 32 is sent to the liquefied gas flow path 121 of the first heat exchanger 12. Through the heat exchange in the first heat exchanger 12, the liquefied gas flowing in the liquefied gas flow path 121 is heated, and the heat medium flowing in the heat medium flow path 122 is cooled. That is, the cold and heat energy of the liquefied gas flowing in the liquefied gas flow path 121 is recovered by the heat medium flowing in the heat medium flow path 122. Through the heat exchange in the first heat exchanger 12, the heat medium flowing in the heat medium flow path 122 becomes a temperature lower than the freezing point of water (heating water).

[0056] The intermediate heat medium whose pressure is increased by the intermediate heat medium circulation pump 61 is sent to the intermediate heat medium flow path 141 of the third heat exchanger 14. In addition, the heating water whose pressure is increased by the heating water pump 51 is sent to the heating water flow path 142. The intermediate heat medium flowing in the intermediate heat medium flow path 141 is heated by the heat exchange in the third heat exchanger 14.

[0057] The heat medium cooled by the first heat exchanger 12 and pressurized by the heat medium circulation pump 41 is sent to the heat medium flow path 131 of the second heat exchanger 13. In addition, the intermediate heat medium heated by the third heat exchanger 14 is sent to the intermediate heat medium flow path 132. Through the heat exchange in the second heat exchanger 13, the heat medium flowing in the heat medium flow path 131 is heated, and the intermediate heat medium flowing in the intermediate heat medium flow path 132 is cooled.

[0058] exist Figure 1 In the illustrated embodiment, the cold and heat power generation system 1 further includes a bypass line 17 that branches from the downstream side of the second heat exchanger 13 in the heat medium circulation line 4, bypasses the turbine 2, and is connected to the upstream side of the heat medium flow path 122 of the first heat exchanger 12. The flow path (the flow path passing through the turbine 2) between the branching portion 171 from which the bypass line 17 branches in the heat medium circulation line 4 and the converging portion 172 where the bypass line 17 merges is used as the main flow path 42.

[0059] exist Figure 1 In the illustrated embodiment, the cold and heat power generation system 1 further includes an on-off valve 43 provided on the upstream side of the turbine 2 in the main flow path 42 and an on-off valve 173 provided in the bypass line 17. For example, at the start-up of the cold and heat power generation system 1, the on-off valve 43 is closed and the on-off valve 173 is opened to allow the heat medium to bypass the turbine 2. After a predetermined period of time has passed, the on-off valve 43 is opened and the on-off valve 173 is closed to allow the heat medium to pass through the turbine 2.

[0060] (Turbine for heat and cold power generation)

[0061] Figure 2 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention.

[0062] like Figure 2 As shown, the turbine 2 for cold and hot power generation in multiple embodiments includes: a rotor shaft 21, a housing 7 for accommodating the rotor shaft 21, at least one moving blade 22 arranged around the rotor shaft 21, at least one stationary blade 23 supported by the housing 7, and a mechanical seal 81 that seals between the rotor shaft 21 and the housing 7 on the upstream side compared to the at least one moving blade 22.

[0063] In the illustrated embodiment, Figure 2 As shown, at least one moving blade 22 includes a plurality of moving blades 22, and the plurality of moving blades 22 include a first moving blade 22A and a second moving blade 22B disposed on the downstream side compared to the first moving blade 22A. Figure 2As shown, the at least one stationary blade 23 includes a plurality of stationary blades 23, and includes a first stationary blade 23A disposed on the upstream side compared to the first moving blade 22A and a second stationary blade 23B disposed on the downstream side compared to the first moving blade 22A and disposed on the upstream side compared to the second moving blade 22B. The heat medium that flows through the main flow path 42 and is introduced into the interior of the housing 7 passes mainly through the first stationary blade 23A, the first moving blade 22A, the second stationary blade 23B, and the second moving blade 22B in this order, and is then discharged to the outside of the housing 7.

[0064] The first moving blade 22A is arranged on one side (right side in the figure) in the axial direction of the turbine 2, that is, in the extending direction of the axis CA of the turbine 2, compared with the second moving blade 22B. Hereinafter, the one side (right side in the figure) in the axial direction of the turbine 2 is defined as the front side, and the side opposite to the one side (left side in the figure) is defined as the rear side. In addition, the radial direction of the turbine 2 may be simply referred to as the radial direction, and the circumferential direction of the turbine 2 may be simply referred to as the circumferential direction.

[0065] The first moving blade 22A is located forward of the second moving blade 22B. The first stationary blade 23A is located forward of the first moving blade 22A, and the second stationary blade 23B is located forward of the second moving blade 22B and rearward of the first moving blade 22A.

[0066] The rotor shaft 21 includes a shaft portion 211 extending along the axis CA of the turbine 2 and a plurality of disk portions 213 protruding radially outward in a disk-like manner from an outer surface 212 of the shaft portion 211. The plurality of disk portions 213 include a front disk portion 213A having first moving blades 22A mounted on the outer periphery thereof and a rear disk portion 213B located on the rear side relative to the front disk portion 213A and having second moving blades 22B mounted on the outer periphery thereof.

[0067] The shell 7 includes: a heat medium inlet portion 72 forming a heat medium inlet flow path 71 for guiding the heat medium to the first stationary blade 23A, a heat medium discharge portion 74 forming a heat medium discharge flow path 73 for guiding the heat medium after passing through the second moving blade 22B to the outside, an outer stationary blade support portion 75 that supports the outer peripheral portion (outer wheel) of the first stationary blade 23A and the outer peripheral portion (outer wheel) of the second stationary blade 23B from the radial outside, an inner stationary blade support portion 76 that supports the inner peripheral portion (inner wheel) of the first stationary blade 23A from the radial inside, and a front inner shell 77 that is arranged on the front side compared to the front side disk portion 213A with a gap.

[0068] In the illustrated embodiment, the heat medium introduction portion 72 is provided on the front side compared to the first stationary blade 23A, and the heat medium discharge portion 74 is provided on the rear side compared to the second moving blade 22B. An introduction port 722 for introducing the heat medium into the interior of the housing 7 is formed on the outer surface 721 of the heat medium introduction portion 72. The introduction port 722 opens outward in the radial direction. An outlet 742 for discharging the heat medium to the outside of the housing 7 is formed on the outer surface 741 of the heat medium discharge portion 74. The outlet 742 opens outward in the radial direction.

[0069] The heat medium introduced into the heat medium introduction flow path 71 from the radially outer side through the introduction port 722 flows from the front side to the rear side in the axial direction, passes through the plurality of stationary blades 23 and the plurality of moving blades 22, and is sent to the heat medium discharge flow path 73. The heat medium sent to the heat medium discharge flow path 73 is discharged to the outside of the housing 7 through the discharge port 742. The heat medium discharged to the outside of the housing 7 is as follows: Figure 1 As shown in the figure, the heat medium is sent to the first heat exchanger 12 through the turbine 2 in the heat medium circulation line 4. The upstream end 401 of the above-mentioned part 4A is connected to the discharge port 742 so that the heat medium can flow, and the downstream end 402 of the above-mentioned part 4A is connected to the upstream end of the heat medium flow path 122 of the first heat exchanger 12 so that the heat medium can flow.

[0070] The outer stationary blade support portion 75 is supported by the heat medium introduction portion 72 and the heat medium discharge portion 74, respectively, and the inner stationary blade support portion 76 is supported by the heat medium introduction portion 72 and the front inner casing 77, respectively. When viewed from the axis CA direction of the turbine 2, the front inner casing 77 is formed in a circular ring shape extending in the radial direction. The inner stationary blade support portion 76 is supported by the outer peripheral portion 771 of the front inner casing 77. The above-mentioned mechanical seal 81 is arranged between the shaft portion 211 of the rotor shaft 21 and the inner peripheral portion 772 of the front inner casing 77, and seals between the shaft portion 211 and the inner peripheral portion 772.

[0071] In the illustrated embodiment, Figure 2 As shown, the outer peripheral portion 771 and the inner peripheral portion 772 of the front inner housing 77 extend in the radial direction respectively, and the inner peripheral portion 772 is located axially forward compared with the outer peripheral portion 771. The front inner housing 77 includes: an outer peripheral portion 771, an inner peripheral portion 772, and an axially extending portion 775, the axially extending portion 775 extends in the axial direction, the rear end 773 is connected to the outer peripheral portion 771, and the front end 774 is connected to the inner peripheral portion 772.

[0072] In the illustrated embodiment, Figure 2As shown, the above-mentioned turbine 2 also includes: a thrust ring 24 installed on the shaft portion 211 of the rotor shaft 21, a front side thrust bearing 25 arranged opposite to the thrust ring 24 on the front side compared with the thrust ring 24, a rear side thrust bearing 26 arranged opposite to the thrust ring 24 on the rear side compared with the thrust ring 24, and a bearing housing 27 that accommodates and internally supports the front side thrust bearing 25 and the rear side thrust bearing 26.

[0073] The turbine 2 for cold and heat power generation in various embodiments is as follows Figure 2 As shown, it comprises: the above-mentioned rotor shaft 21, the above-mentioned casing 7 that accommodates the rotor shaft 21, the above-mentioned at least one moving blade 22 arranged around the rotor shaft 21, the above-mentioned at least one stationary blade 23 supported by the casing 7, a mechanical seal 81 that seals between the rotor shaft 21 and the casing 7 on the upstream side (front side) compared with the at least one moving blade 22, and a pressure reduction line 83, one side 831 of the pressure reduction line 83 is connected to the sealed space 82, and the other side 832 is connected to a low-pressure portion 84 in the heat medium circulation line 4 with a lower pressure than the sealed space 82, the sealed space 82 is formed inside the casing 7 due to the configuration of the mechanical seal 81, and can allow the heat medium leaked from between the at least one stationary blade 23 (23A) and the at least one moving blade 22 (22A) to flow in.

[0074] like Figure 2 As shown, in the illustrated embodiment, the axially extending portion 775 of the front inner housing 77 is formed with a through hole 78 that penetrates to communicate with the inside and outside, and one side 831 of the decompression line 83 is connected to the through hole 78 .

[0075] In the illustrated embodiment, the sealed space 82 is an annular space formed by the front side surface 214 of the front side disk portion 213A and the inner surface 776 of the front inner casing 77 facing the front side surface 214 on the outer peripheral side compared to the shaft portion 211 of the rotor shaft 21. Since the heat medium leaked from between the first stationary blade 23A (in the illustrated example, the primary stationary blade) and the first moving blade 22A (in the illustrated example, the primary moving blade) flows into the sealed space 82, the pressure P1 of the sealed space 82 becomes a high pressure (high pressure compared to the pressure on the atmospheric side of the mechanical seal 81) close to the pressure P2 (nozzle outlet pressure) between the first stationary blade 23A and the first moving blade 22A when the above-mentioned pressure reducing line 83 is not provided.

[0076] According to the above structure, the heat medium in the sealed space 82 is guided to the pressure reduction line 83 from one side 831 of the pressure reduction line 83 by the pressure difference between the sealed space 82 and the low pressure part 84, and after the pressure reduction line 83 flows from one side 831 to the other side 832, it is sent to the low pressure part 84. The low pressure part 84 is provided in the heat medium circulation line 4, so that the heat medium can be suppressed from flowing out to the outside. In this way, by making a part of the heat medium in the sealed space 82 flow out to the low pressure part 84 of the heat medium circulation line 4, the pressure P1 of the sealed space 82 can be reduced. By reducing the pressure P1 of the sealed space 82, the pressure difference between the sealed space side and the atmosphere side on the opposite side of the sealed space side in the mechanical seal 81 can be reduced, and the pressure load applied to the mechanical seal 81 can be reduced. As a result, the risk of deterioration, damage, and leakage of the mechanical seal 81 can be reduced, so the reliability of the shaft seal sealing structure provided with the mechanical seal 81 can be improved.

[0077] In addition, according to the above-mentioned structure, by reducing the pressure P1 of the sealed space 82, the pressure received from the sealed space 82 of the front side disk portion 213A can be reduced, so that the force (thrust) applied in the axial direction of the rotor shaft 21 can be reduced. As a result, the mechanical loss of the turbine 2 for cold and hot power generation can be reduced, and the reliability of the turbine 2 for cold and hot power generation can be improved. In addition, according to the above-mentioned structure, there is no need to provide additional power equipment or the like in the turbine 2 for cold and hot power generation, and it is sufficient to provide the pressure reducing line 83, so that the high price of the turbine 2 for cold and hot power generation can be suppressed.

[0078] Figure 3 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention.

[0079] like Figure 3 As shown, in a plurality of embodiments, the cold and heat power generation turbine 2 further includes a non-contact seal portion 85 that seals between the rotor shaft 21 and the housing 7 on the upstream side of the mechanical seal 81 in the sealed space 82 .

[0080] like Figure 3 As shown, in the illustrated embodiment, the front inner housing 77 further includes a protrusion 777 that protrudes from the axially extending portion 775 toward the radially inner side at the axially rear side relative to the inner peripheral portion 772. Figure 1 In the illustrated embodiment, the protrusion 777 protrudes from the rear end 773 of the axially extending portion 775. The non-contact seal portion 85 is disposed between the shaft portion 211 of the rotor shaft 21 and the protrusion 777 of the front inner housing 77 to seal the space between the shaft portion 211 and the protrusion 777.

[0081] The sealed space 82 is divided into a first sealed space 82A on the upstream side (on the rear side) of the non-contact seal portion 85 and a second sealed space 82B on the downstream side (on the rear side) of the non-contact seal portion 85 by sealing the space between the shaft portion 211 and the protruding portion 777 through the non-contact seal portion 85. The outflow of the heat medium from the first sealed space 82A to the second sealed space 82B is suppressed by the non-contact seal portion 85, so that the pressure P3 of the second sealed space 82B becomes lower than the pressure P1 of the first sealed space 82A.

[0082] According to the above-mentioned structure, the upstream side of the sealed space 82 compared with the mechanical seal 81 is sealed by the non-contact seal portion 85. In this case, the amount of leakage of the heat medium to the downstream side (the second sealed space 82B) compared with the non-contact seal portion 85 is determined by the pressure difference between the upstream side and the downstream side compared with the non-contact seal portion 85, so the amount of leakage of the heat medium to the downstream side compared with the non-contact seal portion 85 can be reduced compared with the case where the non-contact seal portion 85 is not provided. As a result, the pressure on the sealed space side of the mechanical seal 81 can be reduced, and the pressure difference between the sealed space side of the mechanical seal 81 and the atmosphere side on the opposite side to the sealed space side can be reduced, and the pressure load applied to the mechanical seal 81 can be reduced. In addition, according to the above-mentioned structure, by reducing the leakage of the heat medium to the downstream side (the second sealed space 82B) compared with the non-contact seal portion 85, the performance of the turbine 2 for cold and hot power generation can be improved.

[0083] like Figure 3 As shown, in a plurality of embodiments, the non-contact seal portion 85 includes a labyrinth seal 85A. The labyrinth seal 85A is formed on at least one of the protrusion 777 of the front inner housing 77 or the portion of the shaft portion 211 of the rotor shaft 21 that faces the protrusion 777. In the illustrated embodiment, the labyrinth seal 85A is formed on both the protrusion 777 of the front inner housing 77 and the shaft portion 211 of the rotor shaft 21, and a convex portion or a concave portion is formed on the portions that face each other.

[0084] According to the above structure, by using a simple structure labyrinth seal 85A for the non-contact seal portion 85, the sealing performance in the shaft seal seal structure can be ensured, and the high price of the turbine 2 for cold and hot power generation with a shaft seal seal structure can be suppressed. In addition, in other embodiments, a non-contact sealing structure other than the labyrinth seal 85A can also be used for the non-contact seal portion 85.

[0085] like Figure 3As shown, in a plurality of embodiments, one side 831 of the decompression line 83 is connected to a portion between the non-contact seal portion 85 and the mechanical seal 81 in the sealed space 82 (the second sealed space 82B).

[0086] In the illustrated embodiment, the through hole 78 is located on the rear side of the inner peripheral portion 772 and on the front side of the protruding portion 777 , and can allow the heat medium to flow between the second sealed space 82B.

[0087] According to the above structure, the amount of heat medium leakage between the non-contact seal portion 85 and the mechanical seal 81 in the sealed space 82 (the second sealed space 82B) is limited by the non-contact seal portion 85, so that the pressure becomes lower than the upstream side (the first sealed space 82A) of the non-contact seal portion 85. By connecting one side 831 of the pressure-reducing line 83 to the low-pressure sealed space (the second sealed space 82B), the amount of heat medium flowing out to the low-pressure portion 84 through the pressure-reducing line 83 can be reduced compared to the case where one side 831 of the pressure-reducing line 83 is connected to the upstream side (the first sealed space 82A) of the non-contact seal portion 85. By reducing the amount of heat medium flowing out to the low-pressure portion 84 through the pressure-reducing line 83, the efficiency reduction of the turbine 2 for cold and hot power generation can be suppressed.

[0088] Figure 4 This is a schematic cross-sectional view schematically showing a cross section along the axis of a turbine for cold and heat power generation according to an embodiment of the present invention.

[0089] like Figure 4 As shown, in various embodiments, the rotor shaft 21 (specifically, the shaft portion 211) includes a small diameter portion 211A and a large diameter portion 211B having a larger diameter than the small diameter portion 211A. The mechanical seal 81 is mounted on the small diameter portion 211A, and the non-contact seal portion 85 is mounted on the large diameter portion 211B.

[0090] In the illustrated embodiment, Figure 3 As shown in FIG. 1 , the first moving blade 22A is located on the rear side of the first stationary blade 23A in the axial direction, and the non-contact seal portion 85 is located on the front side of the first moving blade 22A in the axial direction. In this case, the thrust received from the heat medium passing through the non-contact seal portion 85 acts on the opposite side to the thrust received from the heat medium passing through the first moving blade 22A, so that the thrust of the rotor shaft 21 can be reduced.

[0091] According to the above structure, the non-contact seal portion 85 is attached to the large diameter portion 211B having a larger diameter than the small diameter portion 211A to which the mechanical seal 81 is attached. In this case, the area of ​​the rotor shaft 21 that contacts the space (first sealed space 82A) on the upstream side of the non-contact seal portion 85 of the sealed space 82 can be reduced, so that the force (thrust) applied to the axial direction of the rotor shaft 21 due to the pressure from the first sealed space 82A can be reduced. As a result, the mechanical loss of the turbine 2 for cold and heat power generation can be reduced, and the reliability of the turbine 2 for cold and heat power generation can be improved.

[0092] In addition, by reducing the thrust of the rotor shaft 21, the thrust bearings (front thrust bearing 25, rear thrust bearing 26) and the thrust ring 24 in the cold and heat power generation turbine 2 can be miniaturized, thereby suppressing the high price of the cold and heat power generation turbine 2. Since the mechanical seal 81 is mounted on the small diameter portion 211A, it can be miniaturized, and further suppressing the high price of the cold and heat power generation turbine 2 having a shaft seal structure.

[0093] In various embodiments, Figure 1 As shown, the above-mentioned low-pressure section 84 includes either a heat exchanger (first heat exchanger 12) configured to perform heat exchange between the heat medium flowing in the heat medium circulation line 4 and the liquefied gas, and a portion 4A in the heat medium circulation line 4 that connects the turbine 2 for cold and hot power generation with the heat exchanger (first heat exchanger 12).

[0094] In the illustrated embodiment, the other side 832 of the pressure reducing line 83 is connected to the heat medium flow path 122 of the first heat exchanger 12 so that the heat medium can flow. Figure 1 As shown by the middle dotted line, the other side 832 of the pressure reduction line 83 is connected to the above-mentioned portion 4A so that the heat medium can flow.

[0095] According to the above-mentioned structure, the leakage destination of the heat medium after passing through the pressure reducing line 83 can be set to the portion 4A connecting the turbine 2 for cold and hot power generation and the heat exchanger (first heat exchanger 12), and the heat exchanger (first heat exchanger 12), so that the complexity of the structure of the pressure reducing line 83 can be suppressed, thereby suppressing the high price of the turbine 2 for cold and hot power generation equipped with the pressure reducing line 83.

[0096] The present invention is not limited to the above-described embodiment, and includes modified embodiments of the above-described embodiment and appropriate combinations of these embodiments.

[0097] The contents described in the above-mentioned multiple embodiments can be understood as follows.

[0098] (1) A turbine 2 for cold and heat power generation according to at least one embodiment of the present invention is a turbine 2 for cold and heat power generation provided in a heat medium circulation line 4 configured to circulate a heat medium for heating liquefied gas, and includes:

[0099] Rotor shaft 21;

[0100] A housing 7, which accommodates the rotor shaft;

[0101] at least one moving blade 22, the at least one moving blade being arranged around the rotor shaft;

[0102] at least one stationary blade 23, the at least one stationary blade being supported by the casing;

[0103] a mechanical seal 81 that seals between the rotor shaft and the housing on an upstream side relative to the at least one moving blade; and

[0104] A pressure reducing line 83, one side of which is connected to the sealed space 82, and the other side is connected to a low-pressure portion 84 in the heat medium circulation line where the pressure is lower than that of the sealed space. The sealed space is formed inside the shell due to the configuration of the mechanical seal, and can allow the heat medium leaked from between the at least one stationary blade and the at least one moving blade to flow in.

[0105] According to the structure of (1) above, the heat medium present in the sealed space is guided to the pressure reducing circuit from one side of the pressure reducing circuit through the pressure difference between the sealed space and the low-pressure part, and is sent to the low-pressure part after the pressure reducing circuit flows from one side to the other side. The low-pressure part is arranged in the heat medium circulation circuit, so that the outflow of the heat medium to the outside can be suppressed. In this way, by making a part of the heat medium present in the sealed space flow out to the low-pressure part of the heat medium circulation circuit, the pressure of the sealed space can be reduced. By reducing the pressure of the sealed space, the pressure difference between the sealed space side of the mechanical seal and the atmospheric side on the opposite side of the sealed space side can be reduced, and then the pressure load applied to the mechanical seal can be reduced. As a result, the risk of deterioration, damage, and leakage of the mechanical seal can be reduced, so the reliability of the turbine for cold and hot power generation can be improved.

[0106] In addition, according to the structure of (1), by reducing the pressure of the sealed space, the force (thrust) applied in the axial direction of the rotor shaft can be reduced. As a result, the mechanical loss of the turbine for cold and hot power generation can be reduced, and the reliability of the turbine for cold and hot power generation can be improved. In addition, according to the structure of (1), there is no need to provide additional power equipment or the like in the turbine for cold and hot power generation, and only a pressure reduction line is required, so that the high price of the turbine for cold and hot power generation can be suppressed.

[0107] (2) In a plurality of embodiments, the turbine 2 for cold and hot power generation described in (1) above further includes a non-contact sealing portion 85 that seals between the rotor shaft 21 and the housing 7 on the upstream side of the mechanical seal 81 in the sealed space 82 .

[0108] According to the structure of (2) above, the upstream side of the sealed space relative to the mechanical seal is sealed by the non-contact sealing portion. In this case, the amount of thermal medium leakage to the downstream side relative to the non-contact sealing portion is determined by the pressure difference between the upstream side and the downstream side relative to the non-contact sealing portion, and thus, the amount of thermal medium leakage to the downstream side relative to the non-contact sealing portion can be reduced compared to a case where the non-contact sealing portion is not provided. Thus, the pressure on the sealed space side of the mechanical seal can be reduced, and thus the pressure difference between the sealed space side of the mechanical seal and the atmospheric side on the opposite side to the sealed space side can be reduced, and thus the pressure load applied to the mechanical seal can be reduced.

[0109] (3) In some embodiments, in the turbine 2 for cold and heat power generation described in (2) above, the non-contact seal portion 85 includes a labyrinth seal 85A.

[0110] According to the configuration of (3), by using a labyrinth seal having a simple structure as the non-contact seal portion, it is possible to ensure the sealing performance in the shaft seal structure and suppress the increase in the price of the turbine for cold and hot power generation including the shaft seal structure.

[0111] (4) In multiple embodiments, in the turbine 2 for cold and hot power generation described in (2) or (3) above, the one side 831 of the pressure reducing line 83 is connected between the non-contact sealing portion 85 in the sealed space 82 and the mechanical seal 81 (second sealed space 82B).

[0112] According to the structure of (4) above, the amount of heat medium leakage between the non-contact seal and the mechanical seal in the sealed space (inter-seal space) is limited by the non-contact seal, so that the pressure is low compared to the upstream side of the non-contact seal. By connecting one side of the pressure-reducing line to the low-pressure inter-seal space, the amount of heat medium flowing out to the low-pressure part through the pressure-reducing line can be reduced compared to the case where one side of the pressure-reducing line is connected to the upstream side of the non-contact seal. By reducing the amount of heat medium flowing out to the low-pressure part through the pressure-reducing line, the efficiency reduction of the turbine for cold and hot power generation can be suppressed.

[0113] (5) In a plurality of embodiments, in the turbine 2 for cold and hot power generation described in any one of (2) to (4),

[0114] The rotor shaft 21 includes a small diameter portion 211A and a large diameter portion 211B having a diameter larger than that of the small diameter portion.

[0115] The mechanical seal 81 is installed on the small diameter portion 211A.

[0116] The non-contact seal portion 85 is mounted on the large diameter portion 211B.

[0117] According to the structure of (5) above, the non-contact seal portion is mounted on the large diameter portion having a larger diameter than the small diameter portion on which the mechanical seal is mounted. In this case, the area of ​​the rotor shaft that contacts the space on the upstream side of the non-contact seal portion of the sealed space can be reduced, thereby reducing the force (thrust) applied to the axial direction of the rotor shaft. As a result, the mechanical loss of the turbine for cold and heat power generation can be reduced, and the reliability of the turbine for cold and heat power generation can be improved.

[0118] In addition, by reducing the thrust, the thrust bearing and thrust ring in the turbine for cold and heat power generation can be miniaturized, thereby suppressing the high price of the turbine for cold and heat power generation. Since the mechanical seal is installed in the small diameter part, it can be miniaturized, thereby suppressing the high price of the turbine for cold and heat power generation.

[0119] (6) In a plurality of embodiments, in the turbine 2 for cold and hot power generation described in any one of (1) to (5),

[0120] The low-pressure section 84 includes either a heat exchanger (a first heat exchanger 12) or a portion 4A in the heat medium circulation line 4 that connects the turbine 2 for cold and hot power generation to the heat exchanger (the first heat exchanger 12), and the heat exchanger is configured to perform heat exchange between the heat medium flowing in the heat medium circulation line 4 and the liquefied gas.

[0121] According to the structure of (6) above, the leakage destination of the heat medium after passing through the pressure reducing line can be set to the portion connecting the turbine for cold and hot power generation and the heat exchanger, or the heat exchanger, thereby suppressing the complexity of the structure of the pressure reducing line and suppressing the high price of the turbine for cold and hot power generation equipped with the pressure reducing line.

[0122] Explanation of symbols

[0123] 1. Cold and heat power generation system

[0124] 2 Turbine

[0125] 21 Rotor shaft

[0126] 211 Shaft

[0127] 211A Small diameter section

[0128] 211B Large diameter part

[0129] 213 Pan

[0130] 213A Front side panel

[0131] 213B rear side panel

[0132] 22 Moving blades

[0133] 22A First moving blade

[0134] 22B Second moving blade

[0135] 23 Stationary blades

[0136] 23A First stationary blade

[0137] 23B Second stationary blade

[0138] 24 Thrust ring

[0139] 25 Front thrust bearing

[0140] 26 Rear thrust bearing

[0141] 27 Bearing housing

[0142] 3 Liquefied gas supply line

[0143] 31 Liquefied gas storage facility

[0144] 32 Pumps for liquefied gas

[0145] 35 Equipment

[0146] 4 Heat medium circulation circuit

[0147] 4A Section (between turbine and first heat exchanger)

[0148] 41 Circulation pump

[0149] 43 On / Off Valve

[0150] 5 Heating water supply line

[0151] 51 Heating water pump

[0152] 6 Intermediate heat medium circulation circuit

[0153] 61 Circulation pump

[0154] 7 Housing

[0155] 71 Heat medium introduction flow path

[0156] 72 Heat medium introduction part

[0157] 73 Heat medium discharge flow path

[0158] 74 Heat medium discharge part

[0159] 75 Outer stationary blade support

[0160] 76 Inner stationary blade support

[0161] 77 Front inner shell

[0162] 771 Peripheral part

[0163] 772 Inner Periphery

[0164] 773 rear end

[0165] 774 front end

[0166] 775 Axial extension

[0167] 776 Inner surface

[0168] 777 Protrusion

[0169] 78 Through hole

[0170] 81 Mechanical seals

[0171] 82 Sealed Space

[0172] 82A First sealed space

[0173] 82B Second sealed space

[0174] 83 Decompression Line

[0175] 84 Low Voltage Department

[0176] 85 Non-contact seal

[0177] 85A Labyrinth seal

[0178] 10 hull

[0179] 11. Generator

[0180] 12. First heat exchanger

[0181] 13. Second heat exchanger

[0182] 14 Third heat exchanger

[0183] 15 Supply Source

[0184] 15A Water Intake

[0185] 16 Discharge destination

[0186] 16A Exhaust port

[0187] 17 Bypass line

[0188] 173 On / Off Valve

[0189] CA axis

[0190] P1, P2, P3 pressure

Claims

1. A turbine for cold and heat power generation, provided in a heat medium circulation circuit configured to circulate a heat medium for heating liquefied gas, It is characterized in that have: Rotor shaft; a housing that receives the rotor shaft; at least one moving blade disposed around the rotor shaft; at least one stationary blade supported by the housing; a mechanical seal that seals between the rotor shaft and the housing at an upstream side relative to the at least one moving blade; as well as a pressure reducing line, one side of which is connected to the sealed space, and the other side of which is connected to a low-pressure portion of the heat medium circulation line whose pressure is lower than that of the sealed space, the sealed space being formed inside the housing due to the arrangement of the mechanical seal and capable of allowing the heat medium leaking from between the at least one stationary blade and the at least one moving blade to flow in, The one side of the decompression line is connected to a through hole that penetrates so as to communicate with the sealed space and the external space of the housing.

2. The turbine for cold and heat power generation according to claim 1, It is characterized in that A non-contact seal portion is further provided, the non-contact seal portion sealing between the rotor shaft and the housing on the upstream side of the mechanical seal in the sealed space.

3. The turbine for cold and heat power generation according to claim 2, It is characterized in that The non-contact sealing portion includes a labyrinth seal.

4. The turbine for cold and heat power generation according to claim 2 or 3, It is characterized in that The one side of the decompression line is connected between the non-contact seal portion and the mechanical seal in the sealed space.

5. The turbine for cold and heat power generation according to claim 2 or 3, It is characterized in that The rotor shaft includes a small diameter portion and a large diameter portion having a diameter larger than the small diameter portion. The mechanical seal is installed on the small diameter portion. The non-contact sealing portion is mounted on the large diameter portion.

6. The turbine for cold and heat power generation according to any one of claims 1 to 3, It is characterized in that The low-pressure section includes a heat exchanger and a portion of the heat medium circulation line connecting the cold and heat power generation turbine and the heat exchanger, the heat exchanger being configured to perform heat exchange between the heat medium flowing in the heat medium circulation line and the liquefied gas.

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