JP2008261234A - Gas seal mechanism and power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology avoiding problems such as air pollution caused by seal gas discharged to the outside, malfunction of a power generator connected to an output shaft, and performance deterioration of a steam turbine caused by mixing of working vapor into the seal gas, in the gas seal mechanism of the steam turbine rotatively driven by working vapor obtained by heating a solution of a non-azeotropic medium mixture made by mixing water and ammonia. <P>SOLUTION: This gas seal mechanism is equipped with: a water vapor introducing means X to introduce water vapor as the seal gas, in an inside gas seal part 61a disposed on the steam turbine 2 side in a gas seal part 61; and an air introducing means Y to introduce air A as the seal gas in an outside gas seal part 61b disposed on the further external side than the inside gas seal part 61a in the gas seal part 61, and a drain part 62 to exhaust the seal gas is disposed in the gas seal part 61. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steam turbine that is rotationally driven by working steam obtained by heating a solution of a non-azeotropic mixture medium obtained by mixing water and ammonia, and rotatably supports the output shaft of the steam turbine and the output shaft. The present invention relates to a gas seal mechanism that introduces a seal gas into a gas seal portion in a gap with a bearing member to prevent the working steam on the steam turbine side from being released to the outside through the gap.

There is known a power system for recovering exhaust heat discharged from a power generation engine or the like to obtain shaft power for driving a generator or the like.
This kind of power system generates a working steam by heating a predetermined solution supplied by a supply pump by exhaust heat such as engine exhaust gas in the working steam generator, and obtained by the working steam in the steam turbine. The above-described condenser is provided with a power circuit that condenses the working steam that has flowed out after the steam turbine is rotationally driven into the solution.

Furthermore, as the power system, a power system that can effectively obtain shaft power from two types of exhaust heat, such as high-temperature exhaust heat exhausted as engine exhaust gas and low-temperature exhaust heat exhausted as engine cooling water. In addition, a system using a water-ammonia non-azeotropic mixed medium obtained by mixing ammonia and water and utilizing the principle of an absorption refrigerator is known (for example, Patent Document 1 and Non-Patent Document 1). reference.).
In this type of power system, a concentrated solution having a high ammonia concentration condensed by a condenser is boosted by a supply pump provided in a concentrated solution flow path and sent to a regenerator, and the concentrated solution is driven by a regenerator. Is heated by low-temperature exhaust heat (cooling water) to separate ammonia vapor from the concentrated solution to form a diluted solution having a low ammonia concentration, and the diluted solution is depressurized by a decompression section provided in the diluted solution flow path. The ammonia vapor separated by the regenerator is joined to the working steam supplied to the steam turbine.
In such a power system, a part of the high-concentration ammonia vapor separated by the regenerator is absorbed in the solution immediately before being supplied to the working steam generator, and the remainder is immediately before being supplied to the steam turbine. By adding to the non-azeotropic mixing medium before being supplied to the steam turbine in the form added to the working steam of the steam turbine, the shaft output of the steam turbine can be increased, which is the low-temperature exhaust heat supplied to the regenerator. It is possible to convert the heat energy of the steam into shaft power of the steam turbine and recover it.
In addition, when the power system as described above is applied to generate power of several thousand kW or less by the shaft output of the steam turbine, a small steam turbine is rotationally driven at a high speed (for example, tens of thousands of rpm) to achieve high efficiency. Is achieved.

  In such a steam turbine that rotates at high speed, the output shaft of the steam turbine and the output shaft can be freely rotated as a seal mechanism for preventing the working steam on the steam turbine side from being discharged to the outside through the gap. A so-called gas seal mechanism is known in which a predetermined seal gas is introduced into a gas seal portion in a gap with a bearing member that is supported by the bearing member (see, for example, Patent Documents 2, 3, and 4).

The gas seal mechanism described in Patent Document 2 is configured to introduce air compressed by an air compressor into the gas seal portion.
On the other hand, in the gas seal mechanism described in Patent Documents 3 and 4, when steam of a low boiling point medium such as ammonia is used as the working steam of the steam turbine, a part of the working steam on the inlet side of the steam turbine is taken out. The extracted steam is introduced into the gas seal portion.
Further, in the gas seal mechanism described in Patent Document 3, the output shaft of the steam turbine that is driven to rotate at high speed is supported by an output shaft of the steam turbine and a bearing member that rotatably supports the output shaft. In this way, it is configured to function as a hydrostatic bearing (gas bearing) for floatingly supporting the output shaft.

JP 2005-171891 A JP 2002-30903 A JP 2001-174098 A JP 2006-63958 A "Development of gas engine exhaust heat utilization technology using ammonia" Hiroshi Fujimoto, Shingo Yakushiji, June 28, 2005, 10th Symposium on Power Energy Technology Symposium OS4-05

  However, in the conventional gas seal mechanism as described above, for example, the vapor of the low boiling point medium as the seal gas introduced into the gas seal portion is discharged to the outside along the axial direction, thereby causing air pollution and output. There is concern about problems such as failure of the generator connected to the shaft, while air as seal gas introduced into the gas seal section is mixed into the working steam of the steam turbine located inside along the axial direction. Therefore, there is a concern that performance degradation of the steam turbine may occur.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a steam turbine that is rotationally driven by working steam formed by heating a solution of a non-azeotropic mixed medium formed by mixing water and ammonia. In the gas seal mechanism, problems such as air pollution due to discharge of the seal gas to the outside, failure of the generator connected to the output shaft, deterioration of the performance of the steam turbine due to mixing of the seal gas into the working steam can be avoided. The point is to provide technology.

In order to achieve the above object, a gas seal mechanism according to the present invention comprises a steam turbine that is rotationally driven by a working steam formed by heating a solution of a non-azeotropic mixed medium obtained by mixing water and ammonia. The seal gas is introduced into the gas seal portion in the gap between the output shaft of the gas turbine and the bearing member that rotatably supports the output shaft, and the steam on the steam turbine side is prevented from being discharged to the outside through the gap. A gas seal mechanism, the first characteristic configuration of which is a water vapor introducing means for introducing water vapor as the seal gas into an inner gas seal portion arranged on the steam turbine side in the gas seal portion,
An air introduction means for introducing air as the seal gas to the outer gas seal portion disposed on the outer side of the inner gas seal portion in the gas seal portion;
A drain portion for discharging the seal gas is disposed in the gas seal portion.

According to the first characteristic configuration of the gas seal mechanism, in the gas seal portion in the gap between the output shaft of the steam turbine and the bearing member, the inner gas seal portion is sequentially formed from the steam turbine side along the axial direction of the output shaft. And the outer gas seal portion are juxtaposed, and further, water vapor is introduced into the inner gas seal portion by the water vapor introducing means, and air is introduced into the outer gas seal portion by the air introducing means. It will be.
Therefore, when air is introduced into the outer gas seal portion disposed outside along the axial direction of the inner gas seal portion, the water vapor introduced into the inner gas seal portion exceeds the outer gas seal portion. Therefore, problems such as air pollution due to the release of the water vapor to the outside and the failure of the generator connected to the output shaft can be avoided. Even if a part of the water vapor introduced into the inner gas seal part flows out into the inner gas seal part and is mixed into the working steam on the steam turbine side, the working steam is essentially water and ammonia. Since the steam is a working steam formed by heating a solution of a non-azeotropic mixture medium, the performance of the steam turbine is hardly deteriorated.
On the other hand, when water vapor is introduced into the inner gas seal portion disposed inside along the axial direction of the outer gas seal portion, the air introduced into the outer gas seal portion exceeds the inner gas seal portion. Therefore, it is possible to prevent the steam from being mixed into the working steam of the steam turbine, and it is possible to avoid the deterioration of the performance of the steam turbine due to the mixing of the air into the working steam. In addition, even if a part of the air introduced into the outer gas seal part flows out to the outside of the outer gas seal part and is released to the outside, it is air. There is no problem such as failure.

  The second characteristic configuration of the gas seal mechanism according to the present invention is that, in addition to the first characteristic configuration, the drain portion is located between the inner gas seal portion and the outer gas seal portion.

According to the second characteristic configuration of the gas seal mechanism, the water vapor flowing out from the inner gas seal portion is discharged as drain gas through the drain portion arranged outside the inner gas seal portion. It is possible to further suppress the water vapor from being discharged to the outside beyond the outer gas seal portion disposed outside the drain portion.
On the other hand, the air flowing out from the outer gas seal portion is discharged as drain gas through the drain portion arranged inside the outer gas seal portion, so that the air is further inside the drain portion. It can suppress further that it mixes with the working steam of a steam turbine beyond the arranged inner gas seal part.

  According to a third characteristic configuration of the gas seal mechanism according to the present invention, in addition to any one of the first to second characteristic configurations, the output shaft is provided between the inner gas seal portion and the outer gas seal portion. The thrust plate accommodating portion is disposed for accommodating the thrust plate provided in the state in which the thrust plate is in contact with the thrust bearing surface provided in the bearing member inward along the axial direction.

  According to the third characteristic configuration of the gas seal mechanism, in the thrust plate housing portion disposed between the inner gas seal portion and the outer gas seal portion, the thrust plate provided on the output shaft and the bearing member are provided. Since the inner gas seal part and the outer gas seal part are separated by the contact part with the thrust bearing surface, the water vapor from the inner gas seal part is further prevented from flowing out to the outside. Furthermore, it is possible to further suppress the air in the outer gas seal portion from flowing out to the inside.

  According to a fourth characteristic configuration of the gas seal mechanism according to the present invention, in addition to any of the first to third characteristic configurations, the bearing member supplies high-pressure steam to the inner gas seal portion by the steam introduction means. By being introduced, the output shaft functions as a hydrostatic bearing that supports the output shaft in a floating manner.

  According to the fourth characteristic configuration of the gas seal mechanism, the steam introducing means introduces high-pressure steam into the inner gas seal portion, whereby the bearing member that functions as the hydrostatic bearing is used to rotate the steam turbine that rotates at high speed. The output shaft can be supported so as to be rotatable easily and appropriately.

In order to achieve the above object, a power system according to the present invention comprises a working steam generating system that generates a working steam by heating a solution of a non-azeotropic mixed medium obtained by mixing water and ammonia by high-temperature exhaust heat from a prime mover. A steam turbine that is rotationally driven by the working steam supplied from the working steam generator, a condenser that cools the working steam flowing out of the steam turbine and condenses it into the solution, and the condensate A power circuit comprising a supply pump for supplying the solution supplied from the vessel to the working steam generator;
A regenerator in which a concentrated solution having a high ammonia concentration is heated by low-temperature exhaust heat from the prime mover to separate ammonia vapor from the concentrated solution to form a dilute solution having a low ammonia concentration, and from the condenser to the regenerator A circulating pump for boosting the concentrated solution and sending it to the regenerator in a concentrated solution channel through which the concentrated solution flows, and a dilute solution channel through which the diluted solution flows from the regenerator to the condenser And a regeneration circuit comprising a decompression unit that decompresses the dilute solution and delivers it to the condenser,
A power system configured to join the ammonia vapor separated by the regenerator to the non-azeotropic mixed medium before being supplied to the steam turbine, the first characteristic configuration of which is the steam turbine The seal gas is introduced into the gas seal portion in the gap between the output shaft of the gas turbine and the bearing member that rotatably supports the output shaft, and the steam on the steam turbine side is prevented from being discharged to the outside through the gap. As the gas seal mechanism, the gas seal mechanism having any one of the first to fourth characteristic configurations is provided.

  According to the first characteristic configuration of the power system, the non-azeotropic mixture medium obtained by mixing water and ammonia is used, and the power circuit and the regeneration circuit are provided. In obtaining shaft power effectively from two types of exhaust heat, the gas seal mechanism according to the present invention can be suitably applied, and it is connected to the air pollution caused by discharge of the seal gas to the outside or to the output shaft. It is possible to avoid problems such as a malfunction of the generator and a deterioration in the performance of the steam turbine due to the mixing of the seal gas into the working steam.

  According to a second characteristic configuration of the power system according to the present invention, in addition to the first characteristic configuration, the water vapor introducing means heats the dilute solution taken out from the dilute solution flow path by the high-temperature exhaust heat of the prime mover, thereby adding ammonia. The point is that water vapor having a low concentration is generated, and the generated water vapor is introduced into the inner gas seal portion.

According to the second characteristic configuration of the power system, there is no need to add water or a heat source separately by the water vapor introducing means, and the high temperature of the prime mover in the power circuit and the dilute solution taken out from the dilute solution flow path in the regeneration circuit. Water vapor can be introduced into the inner gas seal portion of the gas seal mechanism using the exhaust heat.
That is, by heating the dilute solution with the high-temperature exhaust heat, water vapor having a low ammonia concentration can be generated, and the water vapor can be introduced into the inner gas seal portion of the gas seal mechanism.

The power system according to the third aspect of the present invention includes, in addition to the second characteristic configuration, a denitration processing unit that denitrates and discharges the exhaust gas of the engine while the prime mover is an engine.
The drain gas discharged from the drain portion is allowed to flow into the inlet side of the denitration processing portion.

  According to the fourth characteristic configuration of the power system, when water vapor obtained by heating a dilute solution having a low ammonia concentration is introduced into the inner gas seal portion, the ammonia contained in the drain gas discharged from the drain portion is used as it is in the atmosphere. It is possible to render it harmless by letting it pass through the denitration section together with the engine exhaust gas without being released into the exhaust gas.

A fourth characteristic configuration of the power system according to the present invention is an engine in which the prime mover includes a supercharger in addition to any of the first to third characteristic configurations described above.
The air introduction means is configured to take out the air pressurized by the supercharger and introduce the taken-out air into the outer gas seal portion.

  According to the fourth characteristic configuration of the power system, it is not necessary to add an additional air compressor or the like by the air introduction unit, and the pressurized air taken out from the downstream side of the supercharger of the engine is gas. It can be introduced into the outer gas seal portion of the seal mechanism.

Embodiments of the present invention will be described with reference to the drawings.
1 is a schematic configuration diagram of the power system, and FIG. 2 is a side sectional view of a gas seal mechanism provided in the power system.

First, the basic configuration of the power system will be described with reference to FIG.
The power system uses the exhaust heat of the engine exhaust gas E discharged from the engine 21 as a prime mover as high-temperature exhaust heat, and the exhaust heat of the engine coolant JW that cools the engine 21 as low-temperature exhaust heat. It is configured to use a cycle in which exhaust heat is efficiently recovered from the water JW and shaft power for driving the generator 80 by the steam turbine 2 is output.

The power system includes a power circuit 30 including a working steam generator 1, a steam turbine 2, a condenser 3, and supply pumps 14 and 16, which will be described later in detail. ing. Hereinafter, the detailed configuration of the power circuit 30 will be described.
The working steam generator 1 generates the working steam S by heating the working fluid solution L by heat exchange with the engine exhaust gas E supplied from the engine 21 through the exhaust passage 23.
The steam turbine 2 rotationally drives the output shaft 2 b with the working steam S supplied from the working steam generator 1 through the working steam inflow passage 11. The rotational power output from the output shaft 2 b of the steam turbine 2 is used as a drive source for driving the generator 80.

  The condenser 3 cools the working steam S that has flowed out of the steam turbine 2 and supplied through the working steam outflow passage 12 by heat exchange with cooling water, and condenses it into the solution L. Further, the condenser 3 is provided with a cooling pipe 3a through which the cooling water C1 flows, and the cooling water C1 flows through the cooling pipe 3a, whereby the working steam S, the solution L, and the cooling water are supplied. Heat exchange with C1 is performed, and latent heat of condensation and mixed heat generated when the working steam S is condensed and mixed with the solution L can be recovered by the cooling water C1.

The supply pumps 14 and 16 supply the solution L supplied from the condenser 3 to the working steam generator 1 through the flow paths 13 and 15. Specifically, the supply pump 14 supplies the solution L from the condenser 3 to the absorber 5 to be described later, and the supply pump 16 supplies the solution L from the absorber 5 to the working steam generator 1. To do.
In the power circuit 30, the working fluid circulates through the working steam generator 1, the steam turbine 2, the condenser 3, the supply pump 14, the absorber 5, and the supply pump 16 in this order.

  Furthermore, the power system uses a non-azeotropic mixture medium such as a water-ammonia system of ammonia as a refrigerant and water as an absorbing solution capable of absorbing the ammonia as a working fluid, and the principle of an absorption refrigeration machine. In order to effectively recover two types of exhaust heat, high-temperature exhaust heat that is exhaust heat of the engine exhaust gas E and low-temperature exhaust heat that is exhaust heat of the engine cooling water JW, the regenerator 4 and the circulation A regeneration circuit 35 in which the pump 17 and the pressure reducing valve 20 are arranged is provided. Hereinafter, a detailed configuration of the reproduction circuit 35 will be described.

  The regenerator 4 heats the concentrated solution L1 having a high ammonia concentration by the engine cooling water JW, which is the low-temperature exhaust heat of the engine 21, and separates the ammonia vapor Sa from the concentrated solution L1, thereby diluting the diluted solution L2 having a low ammonia concentration. And The regenerator 4 is provided with a heating pipe 4a through which the engine cooling water JW flows, and the engine cooling water JW circulated by the pump 24 between the heating pipe 4a and the engine 21 is passed through the heating pipe 4a. By flowing, the heat exchange between the working fluid solution L and the engine coolant JW is performed.

The circulation pump 17 boosts the concentrated solution L1 in the concentrated solution channel 18 through which the concentrated solution L1 having a high ammonia concentration flows from the condenser 3 toward the regenerator 4 and sends the concentrated solution L1 to the regenerator 4.
The pressure reducing valve 20 (an example of a pressure reducing unit) depressurizes the dilute solution L2 in the dilute solution flow path 19 through which the dilute solution L2 flows from the regenerator 4 toward the condenser 3 and sends it to the condenser 3.

  That is, the concentrated solution L1 having a relatively high ammonia concentration after the working steam S supplied from the steam turbine 2 in the condenser 3 is mixed is pressurized by the circulation pump 17 from the condenser 3 through the concentrated solution flow path 18. On the other hand, the dilute solution L2 having a relatively low ammonia concentration after the ammonia vapor Sa is separated by the regenerator 4 is supplied from the regenerator 4 through the dilute solution flow path 19 by the pressure reducing valve 20. By being supplied to the condenser 3 after being decompressed, the solution L is circulated between the high pressure regenerator 4 and the low pressure condenser 3 while maintaining the pressure difference.

  Further, the power system increases the shaft output of the steam turbine 2 by joining the ammonia vapor Sa separated by the regenerator 4 in the regeneration circuit 35 to the working fluid supplied to the steam turbine 2 in the power circuit 30. The heat energy of the low-temperature exhaust heat supplied to the regenerator 4 as exhaust heat of the engine cooling water JW is converted into shaft power of the steam turbine 2 and recovered, and the detailed configuration will be described below. To do.

The power system includes an absorber 5 that absorbs at least a part of the ammonia vapor Sa separated by the regenerator 4 and flowing into the ammonia vapor flow path 10 into the solution L supplied to the working steam generator 1 from the supply pump 14. It has been.
That is, in the absorber 5, the ammonia vapor Sa supplied through the branch passage 10 a branched from the ammonia vapor passage 10 is absorbed into the working fluid solution L supplied from the condenser 3 through the passage 13 by the supply pump 14. Thus, a working fluid solution L having a very high ammonia concentration is generated, and the solution L is further pressurized by the supply pump 16 and supplied to the working steam generator 1 through the flow path 15.
Therefore, even if the ammonia vapor Sa separated by the regenerator 4 is at a relatively low pressure, the absorber 5 can absorb the low-pressure ammonia vapor Sa satisfactorily into the solution, and further, the generation of the working steam can be performed. Since the heat of a large amount of engine exhaust gas E can be recovered by the high-concentration solution L in the vessel 1, a large amount of working steam S can be supplied to the steam turbine 2 to increase the shaft output of the steam turbine 2.

Further, in the working steam generator 1, the temperature of the engine exhaust gas E flowing through the exhaust passage 23 is lowered by applying heat to the solution L. That is, the temperature difference between the inlet side and the outlet side of the working steam generator 1 in the exhaust passage 23 is substantially proportional to the heat recovery amount for the engine exhaust gas E in the working steam generator 1.
Then, the working steam generator 1 circulates the solution L having a high ammonia concentration in the absorber 5 from the downstream side to the upstream side of the exhaust passage 23 to heat the engine exhaust gas E flowing through the exhaust passage 23. To the solution L.
Therefore, in the working steam generator 1, in the vicinity of the downstream side in the exhaust passage 23 (the outlet side of the engine exhaust gas E with respect to the working steam generator 1), ammonia contained in the solution L at a high concentration is compared with the engine exhaust gas E having a relatively low temperature. Therefore, a large amount of working steam S can be supplied to the steam turbine 2, and even if the temperature of the engine exhaust gas E on the upstream side in the exhaust passage 23 is constant, the downstream side Since the temperature of the engine exhaust gas E can be sufficiently reduced, the amount of heat recovered from the engine exhaust gas E in the working steam generator 1 can be increased.

Further, the absorber 5 is provided with a cooling pipe 5a through which the cooling water C2 flows, and when the cooling water C2 flows through the cooling pipe 5a, the ammonia vapor Sa and the solution L and the cooling water C2 Heat exchange between the two is performed, and the absorption heat generated when the ammonia vapor Sa is absorbed by the solution L can be recovered by the cooling water C2.
Moreover, since the absorber 5 is generally hotter than the condenser 3, the cooling water C2 supplied to the absorber 5 is the cooling water C1 after heat recovery by the condenser 3 described above. be able to. Note that the cooling water C1 and C2 may be separately supplied to the condenser 3 and the absorber 5.

Further, the power system is configured to supply at least a part of the ammonia vapor Sa separated by the regenerator 4 and flowing out to the ammonia vapor flow path 10 to the low pressure stage 2 a of the steam turbine 2.
That is, the remainder of the ammonia vapor Sa that could not be absorbed in the solution L by the absorber 5 is supplied to the low-pressure stage 2 a of the steam turbine 2 through the branch passage 10 b branched from the ammonia vapor passage 10.
Therefore, even if the ammonia vapor Sa separated by the regenerator 4 is at a relatively low pressure, the low-pressure ammonia vapor Sa is supplied to the low-pressure stage 2a of the steam turbine 2 at a relatively low pressure, and the steam turbine 2 The shaft output can be increased.

Furthermore, this power system introduces a seal gas into the gas seal portion 61 in the gap between the output shaft 2b of the steam turbine 2 and the bearing member 60 that rotatably supports the output shaft 2b, so that the steam turbine 2 side A gas seal mechanism is provided for preventing the working steam S from being discharged outside through the gap.
This gas seal mechanism releases the seal gas to the outside even when the small steam turbine 2 is rotationally driven at a very high speed (for example, tens of thousands of rpm) so that the generator 80 can generate power of several thousand kW or less. The system is configured to avoid problems such as air pollution due to the above, failure of the generator 80 connected to the output shaft 2b, and deterioration of the performance of the steam turbine 2 due to mixing of the seal gas into the working steam S. Hereinafter, the detailed configuration of the gas seal mechanism will be described with reference to FIG.

As shown in FIG. 2, the gas seal mechanism includes an inner gas seal portion 61a disposed on the steam turbine 2 side of the gas seal portion 61. As will be described in detail later, water vapor Sw containing some ammonia is used as a seal gas. A water vapor introducing means X to be introduced is provided.
The water vapor introducing means X is formed between the outer surface of the thrust plate 63 and the inner surface of the bearing member 60 that are externally fitted to the steam turbine 2 side of the output shaft 2b that is rotationally driven (that is, the left side of the output shaft 2b in FIG. The gap is defined as the inner gas seal portion 61a, and is constituted by a water vapor introduction passage 42 for supplying the water vapor Sw to the inner gas seal portion 61a.
The bearing member 60 functions as a hydrostatic bearing that floats and supports the output shaft 2b that is driven to rotate at a high speed by introducing the steam Sw at a high pressure into the inner gas seal portion 61a by the steam introduction means X. It is configured.

Further, the gas seal mechanism is provided with an air introduction means Y for introducing air A as a seal gas into the outer gas seal portion 61b disposed outside the inner gas seal portion 61a in the gas seal portion 61. Yes.
The air introduction means Y is formed by a sleeve 67 that is externally fitted to the generator 80 side (that is, the right side of the output shaft 2b in FIG. 2) from the thrust plate 63 of the output shaft 2b that is rotationally driven with the bearing member 60. A gap between the outer surface and the inner surface of the bearing member 60 is defined as the outer gas seal portion 61b, and is configured by an air introduction path 45 that supplies air A to the outer gas seal portion 61b.

  And in the gas seal mechanism comprised in this way, air A is introduce | transduced into the outer gas seal part 61b arrange | positioned along the axial direction of the said inner gas seal part 61a on the outer side (right side in FIG. 2). The water vapor Sw introduced into the inner gas seal portion 61a is suppressed from being discharged to the outside beyond the outer gas seal portion 61b, and air pollution caused by the discharge of the water vapor Sw to the outside or the output shaft 2b. A failure or the like of the connected generator 80 is avoided.

  On the other hand, the air introduced into the outer gas seal portion 61b by introducing the water vapor Sw into the inner gas seal portion 61a disposed on the inner side (left side in FIG. 2) along the axial direction of the outer gas seal portion 61b. A is suppressed from being mixed into the working steam S of the steam turbine 2 beyond the inner gas seal portion 61a, and the performance deterioration of the steam turbine 2 due to the mixing of the air A into the working steam S is avoided. Has been.

Even if a part of the water vapor Sw introduced into the inner gas seal portion 61a flows out into the inner gas seal portion 61a and is mixed into the working steam S on the steam turbine 2 side, the working steam is originally. Since S is the working steam S obtained by heating the solution L of the non-azeotropic mixture medium obtained by mixing water and ammonia, the performance of the steam turbine 2 hardly decreases.
On the other hand, even if a part of the air A introduced into the outer gas seal portion 61b flows out to the outside of the outer gas seal portion 61b and is released to the outside, it is the air A. There is no problem such as failure of the generator 80.

The output shaft 2b includes a thrust plate 63 including a cylindrical portion that externally fits the output shaft 2b and a flange-shaped portion that extends radially outward from an end of the cylindrical portion on the generator 80 side. It is provided so as to be rotationally driven together with the output shaft 2b.
On the other hand, between the inner gas seal portion 61 a and the outer gas seal portion 61 b of the bearing member 60, a thrust plate 63 provided on the output shaft 2 b is disposed with respect to the thrust bearing surface 64 provided on the bearing member 60. A thrust plate accommodating portion 65 is disposed that accommodates in an inward contact state along the axial direction (that is, a direction toward the steam turbine 2).
Therefore, in the thrust plate housing portion 65, the inner gas seal portion 61a and the outer gas seal portion 61b are isolated by the contact portion between the thrust plate 63 and the thrust bearing surface 64, so that the generator 80 of the water vapor Sw is generated. Outflow to the side and outflow of air A to the steam turbine 2 side are further suppressed.

The gas seal portion 61 is provided with a drain portion 62 that discharges the steam Sw or the seal gas of the air A as a drain gas D to the outside. The drain portion 62 includes an inner gas seal portion 61a and an outer gas seal. It is located between the part 61b.
Therefore, each of the water vapor Sw flowing from the inner gas seal portion 61a toward the generator 80 side and the air A flowing from the outer gas seal portion 61b toward the steam turbine 2 side are respectively connected to the inner gas seal portion 61a and the outer gas seal. It will be discharged as drain gas D through the drain part 62 located between the parts 61b, and the outflow of the water vapor Sw to the generator 80 side and the outflow of the air A to the steam turbine 2 side are further suppressed.

Further, the number of the drain portions 62 may naturally be one, but in this embodiment, the inner drain portion 62a located on the steam turbine 2 side with respect to the thrust plate housing portion 65 and the outer side located on the thrust plate housing portion 65. A drain portion 62b is provided.
Therefore, the water vapor Sw flowing from the inner gas seal portion 61a toward the generator 80 side is mainly discharged to the outside as the inner drain gas Da through the inner drain portion 62a, and on the other hand, from the outer gas seal portion 61b toward the steam turbine 2 side. The flowing air A is mainly discharged to the outside as the outer drain gas Db through the outer drain portion 62b. Each of the drain gases Da and Db may be processed individually or may be combined and processed at the same time.

  In adopting the gas seal mechanism configured as described above in the power system described above, a configuration for appropriately supplying the water vapor Sw and the air A as the seal gas and discharging the drain gas D in the drain part 62 It has. Hereinafter, the characteristic configuration of the power system will be described with reference to FIG.

  In the power system shown in FIGS. 1 and 2, the water vapor introducing means X in the gas seal mechanism uses the engine exhaust gas E, which is the high-temperature exhaust heat of the engine 21, to remove the dilute solution L2 taken out from the dilute solution flow path 19 in the regeneration circuit 35. Heat is generated to generate water vapor Sw having a low ammonia concentration, and the generated water vapor Sw is introduced into the inner gas seal portion 61a of the gas seal mechanism.

That is, the water vapor introducing means X is connected to the upstream side of the pressure reducing valve 20 in the dilute solution flow path 19 and a dilute solution take-out flow path 41 into which a part of the dilute solution L2 flows from the dilute solution flow path 19; Water vapor Sw containing some ammonia by heating the dilute solution L2 supplied through the dilute solution take-off channel 41 by heat exchange with the high-temperature engine exhaust gas E flowing upstream of the working steam generator 1 in the exhaust passage 23. And a water vapor introduction path 42 for introducing the water vapor Sw generated by the water vapor generator 40 into the inner gas seal portion 61a of the gas seal mechanism.
Therefore, in this power system, it is not necessary to add water or a heat source separately in order to generate the water vapor Sw used in the gas seal mechanism.

By introducing the water vapor Sw containing a little ammonia into the inner gas seal part 61a, the drain gas D discharged from the drain part 62 contains a little ammonia.
Therefore, the exhaust passage 23 of the engine 21 is provided with a denitration catalyst 26 (an example of a denitration treatment unit) for denitrating the engine exhaust gas E, and further, the other end of the drain channel 47 connected to the drain unit 62. The drain gas D discharged from the drain part 62 flows into the inlet side of the denitration catalyst 26 by connecting the side to the upstream side of the denitration catalyst 26 in the exhaust passage 23.
Accordingly, the drain gas D is not released into the atmosphere as it is, but is discharged after detoxifying the engine exhaust gas E through the denitration catalyst 26.

Furthermore, the engine 21 has a supercharger 25 for pressurizing the air A taken into the intake passage 22 and supplying it to the combustion chamber (not shown). The means Y is configured to take out the air A pressurized by the supercharger 25 and introduce the taken out air A into the outer gas seal portion 61b in the gas seal mechanism.
That is, the air introduction means Y is connected to the downstream side of the supercharger 25 in the intake passage 22 and a part of the air A pressurized from the intake passage 22 flows in, and the air A is used in the gas seal mechanism. An air introduction path 45 is provided to be introduced into the outer gas seal portion 61b.
Therefore, in this power system, it is not necessary to add a separate air compressor or the like in order to pressurize the air A used in the gas seal mechanism.

[Another embodiment]
(1) In the above embodiment, the generator 80 is driven by the shaft power of the steam turbine 2, but in the present invention, the shaft power of the steam turbine 2 is, for example, the compression power of a compression heat pump. It may be used for other purposes.

(2) In the above embodiment, at least a part of the ammonia vapor Sa separated by the regenerator 4 is absorbed by the solution L supplied from the supply pump 14 to the working steam generator 1 by the absorber 5. However, if the ammonia vapor Sa is combined with the working fluid supplied to the steam turbine 2, these configurations are modified as appropriate. It doesn't matter.

(3) In the above embodiment, the heat source of the high-temperature exhaust heat and the low-temperature exhaust heat of the working steam generator 1 and the regenerator 4 is the exhaust heat of the engine 21, but another exhaust such as exhaust heat of the fuel cell is used. Heat may be used as a heat source.

  The gas seal mechanism according to the present invention avoids problems such as air pollution due to release of the seal gas to the outside, failure of the generator connected to the output shaft, and deterioration of the performance of the steam turbine due to mixing of the seal gas into the working steam. It can be used effectively as something that can be done.

Schematic configuration diagram of power system Side view of gas seal mechanism

Explanation of symbols

1: Working steam generator 2b: Output shaft 2: Steam turbine 3: Condenser 4: Regenerator 14, 16: Supply pump 17: Circulation pump 18: Concentrated solution flow path 20: Pressure reducing valve 21: Engine (motor)
25: Supercharger 26: Denitration catalyst (denitration processing section)
30: Power circuit 35: Regeneration circuit 60: Bearing member 61: Gas seal part 61b: Outer gas seal part 61a: Inner gas seal part 62: Drain part 63: Thrust plate 64: Thrust bearing surface 65: Thrust plate housing part A: Air D: Drain gas Db: Outer drain gas E: Engine exhaust gas (high temperature exhaust heat)
JW: Engine cooling water (low temperature exhaust heat)
L: Solution L1: Concentrated solution L2: Dilute solution S: Working steam Sw: Steam X: Steam introduction means Y: Air introduction means

Claims (8)

In a steam turbine that is rotationally driven by working steam formed by heating a solution of a non-azeotropic mixture medium obtained by mixing water and ammonia, an output shaft of the steam turbine and a bearing member that rotatably supports the output shaft; A gas seal mechanism that introduces a seal gas into the gas seal portion of the gap to prevent the working steam on the steam turbine side from being released to the outside through the gap,
Water vapor introducing means for introducing water vapor as the seal gas into the inner gas seal portion disposed on the steam turbine side in the gas seal portion;
An air introduction means for introducing air as the seal gas to the outer gas seal portion disposed on the outer side of the inner gas seal portion in the gas seal portion;
A gas seal mechanism in which a drain portion for discharging the seal gas is disposed in the gas seal portion.   The gas seal mechanism according to claim 1, wherein the drain portion is located between the inner gas seal portion and the outer gas seal portion.   Between the inner gas seal portion and the outer gas seal portion, a thrust plate provided on the output shaft abuts inward along an axial direction with respect to a thrust bearing surface provided on the bearing member. The gas seal mechanism according to claim 1 or 2, wherein a thrust plate accommodating portion that is accommodated in a state in which the gas is sealed is disposed.   The said bearing member functions as a static pressure bearing which floats and supports the said output shaft by introduce | transducing high-pressure water vapor | steam into the said inner side gas-seal part by the said water vapor | steam introduction means. Gas seal mechanism. A working steam generator that generates a working steam by heating a solution of a non-azeotropic mixed medium formed by mixing water and ammonia by high-temperature exhaust heat of a prime mover, and the working steam supplied from the working steam generator A steam turbine that is driven by rotation, a condenser that cools the working steam flowing out of the steam turbine and condenses it into the solution, and supplies the solution supplied from the condenser to the working steam generator A power circuit in which a supply pump is arranged;
A regenerator in which a concentrated solution having a high ammonia concentration is heated by low-temperature exhaust heat from the prime mover to separate ammonia vapor from the concentrated solution to form a dilute solution having a low ammonia concentration, and from the condenser to the regenerator A circulating pump for boosting the concentrated solution and sending it to the regenerator in a concentrated solution channel through which the concentrated solution flows, and a dilute solution channel through which the diluted solution flows from the regenerator to the condenser And a regeneration circuit comprising a decompression unit that decompresses the dilute solution and delivers it to the condenser,
A power system configured to join the ammonia vapor separated by the regenerator to the non-azeotropic mixed medium before being supplied to the steam turbine,
Seal gas is introduced into a gas seal portion in a gap between the output shaft of the steam turbine and a bearing member that rotatably supports the output shaft, and the working steam on the steam turbine side is released to the outside through the gap. The power system provided with the gas seal mechanism as described in any one of Claims 1-4 as a gas seal mechanism which prevents this.   The water vapor introducing means heats the dilute solution taken out from the dilute solution flow path by high-temperature exhaust heat of the prime mover to generate water vapor having a low ammonia concentration, and introduces the generated water vapor into the inner gas seal portion. Item 6. The power system according to Item 5. The prime mover is an engine, and includes a denitration processing unit that denitrates and discharges exhaust gas from the engine,
The power system according to claim 6, wherein drain gas discharged from the drain part is caused to flow into an inlet side of the denitration processing part. The prime mover is an engine having a supercharger;
The said air introduction means is comprised so that the air pressurized with the said supercharger may be taken out, and the said taken-out air may be introduce | transduced into the said outer side gas seal part. Power system.

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