JP2014047676A - Steam turbine and binary generator with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam turbine capable of simply and inexpensively preventing a flammable medium from leaking out and to provide a binary generator with the steam turbine.SOLUTION: A steam turbine comprises: a steam turbine 9 which is rotated by vaporized working fluid (a flammable medium); a seal section 70a which seals a rotation shaft 70 of the steam turbine 9; a vapor extraction section 11 which extracts the working fluid leaked from the seal section 70a; and a combustion chamber 13 where the working fluid introduced from the vapor extraction section 11 is combusted.

Description

  The present invention relates to a steam turbine suitable for use particularly in geothermal power generation and a binary power generation apparatus including the same.

  The geothermal power generation facility excavates underground to a predetermined depth, injects a geothermal fluid that coexists with steam and hot water under high pressure in the deep underground, and separates this geothermal fluid into steam and hot water using a separator. In general, the separated steam drives and rotates a turbine to generate electric power.

  In addition, geothermal power generation is impossible due to low underground temperature and pressure, and even when only hot water is available, a heat medium (flammable medium) having a lower boiling point than water such as ammonia, pentane and chlorofluorocarbon is used. There is known a binary power generation that can be used as a working fluid and boil this heat medium with hot water and rotate a steam turbine to generate power.

  In such binary power generation, there is a problem that a low-boiling-point heat medium as a working fluid leaks to the outside from a seal portion such as a turbine or a pump of the binary power generation apparatus.

  As measures against these problems, for example, there are those described in Patent Documents 1 and 2 below.

  In Patent Document 1, the liquid level of the working fluid is monitored when the working fluid reduced due to leakage or the like is replenished, and the required replenishment amount of the entire working fluid is calculated based on the amount of change in the liquid level when the liquid level decreases. Then, measure the temperature and pressure of the working fluid vapor in the evaporator, calculate the current concentration of the working fluid from those measured values, compare the current concentration with the set concentration, A method for replenishing a non-azeotropic mixed medium in which an additional filling amount for each component is determined by determining a ratio of each component necessary for obtaining is shown.

  Since the ratio of each component that should occupy the required replenishment amount of the entire working fluid is determined according to the temperature of the working fluid and additional filling is performed for each component, it is shown that replenishment can be performed while maintaining the set temperature. ing.

Japanese Patent Laid-Open No. 3-100307

  In the geothermal power generation system disclosed in Patent Document 1, it is possible to replenish while maintaining the set temperature by replenishing the leaked working fluid. This enables stable operation without stopping the system. However, since the leaked working fluid is a flammable medium, there is a problem of causing a fire. There was also a problem of pollution to the surrounding environment.

  In addition, in order to prevent leakage of these flammable fluids (for example, hydrocarbon-based media), there is a problem in that the cost increases when a structure having a high sealing property is employed for the seal portion of the operating device.

  The present invention has been made in view of such circumstances, and a steam turbine capable of preventing leakage of a combustible medium to the outside simply and at a reduced cost, and a binary power generation apparatus including the same The purpose is to provide.

  In order to solve the above-described problems, the steam turbine of the present invention and the binary power generation apparatus including the same employ the following means. The steam turbine according to the present invention includes a steam turbine rotated by a combustible medium converted into steam, a seal portion that seals a rotating shaft of the steam turbine, and an extraction air that extracts the combustible medium leaked from the seal portion. And a combustion chamber in which the combustible medium guided from the extraction unit is combusted.

The combustible medium (for example, hydrocarbon-based combustible material) leaked from the seal portion of the steam turbine is guided to the combustion chamber by the extraction unit. By collecting the flammable medium leaked from the seal portion and burning it in the combustion chamber for processing, the safety of the facility can be improved.
Further, for example, if the fuel is burned in the combustion chamber and then released to the outside, pollution to the surrounding environment can be prevented.
In addition, since the seal portion can be designed to allow leakage, an inexpensive seal portion such as a labyrinth seal can be obtained. Therefore, the cost of equipment can be reduced.

  Furthermore, the steam turbine according to the present invention includes a heat exchanger for recovering heat from the exhaust gas discharged from the combustion chamber.

  The heat of the exhaust gas can be recovered by passing it through a heat exchanger that recovers heat from the exhaust gas after combustion. Thereby, the efficiency of equipment can be improved.

  Furthermore, in the steam turbine of the present invention, the combustion chamber is a boiler or an internal combustion engine combustor.

  The combustible medium leaked from the seal portion is supplied to an internal combustion engine (for example, an engine) or a combustor such as a boiler, and burned using it as fuel. Thereby, the leaked combustible medium can be effectively used without waste.

  Furthermore, in the steam turbine of the present invention, an ejector is provided in the extraction part.

  By providing an ejector in the bleed portion, the combustible medium leaked from the seal portion can be sucked. Further, by using the ejector, the leakage medium and air can be mixed and transferred to the combustion chamber.

  Furthermore, in the binary power generation device of the present invention, the steam turbine, a separator for separating high-temperature and high-pressure geothermal water led from the production well into steam and hot water, and the steam led from the separator are combustible. An evaporator for evaporating a medium, a generator for generating electric power driven by the steam turbine driven by steam of the combustible medium guided from the evaporator, and the combustible medium guided from the steam turbine. And a condenser for condensing.

  By using a steam turbine for binary power generation, the safety of the facility can be improved. Further, the combustible medium can be used without waste. Thereby, the efficiency of power generation equipment can be improved.

  Furthermore, the binary power generator of the present invention further includes a heating heat exchanger for exchanging heat between the combustion gas generated in the combustion chamber and the combustible medium, and the heating heat exchanger is located upstream of the steam turbine. It is provided in.

  Since the energy after combustion of the combustible medium is large, a heating heat exchanger used as a heater utilizing the exhaust heat of the combustion chamber that combusts the combustible medium is provided. Accordingly, the combustible medium before being supplied to the steam turbine can be heated without wasting exhaust heat due to combustion of the combustible medium. Therefore, high turbine efficiency can be obtained.

  Furthermore, in the binary power generation device of the present invention, the heat exchanger for heating is provided between the evaporator and the condenser and / or between the steam turbine and the evaporator. It is characterized by.

  The heat exchanger for heating was provided between the evaporator and the condenser and / or between the steam turbine and the evaporator. Thereby, the combustible medium before supplying to a steam turbine can be heated. Thereby, since a combustible medium can be heated efficiently, turbine efficiency can be improved.

According to the present invention, the following operational effects can be obtained.
By collecting the flammable medium leaked from the seal portion of the steam turbine and burning it in the combustion chamber, the safety of the equipment can be improved. Further, for example, if the fuel is burned in the combustion chamber and then released to the outside, pollution to the surrounding environment can be prevented. Furthermore, since the design allows the leakage of the seal portion, an inexpensive seal portion such as a labyrinth seal can be obtained. Therefore, the cost of equipment can be reduced.

It is a schematic block diagram which shows 3rd Embodiment of the steam turbine of this invention and the binary electric power generating apparatus provided with the same. It is a schematic block diagram which shows 2nd Embodiment of the steam turbine of this invention and the binary electric power generating apparatus provided with the same. It is a principal part schematic sectional drawing which shows the extraction part used for 1st Embodiment and 2nd Embodiment of the steam turbine of this invention and the binary electric power generating apparatus provided with the same. It is a schematic block diagram which shows the modification of 1st Embodiment of the steam turbine of this invention, and the binary power generator provided with the same. It is a schematic block diagram which shows 4th Embodiment of the steam turbine of this invention and a binary electric power generating apparatus provided with the same.

  Hereinafter, embodiments of a steam turbine and a binary power generation apparatus including the steam turbine according to the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 4, the steam turbine and the binary power generation apparatus including the steam turbine include a separator 3, an evaporator 7, a preheater 23, a heat exchanger 23 a for heating, a steam turbine 9, and power generation. The machine 10, the condenser 16, and the cooling tower 20 are provided.

  A separator 3 is provided that separates high-temperature and high-pressure geothermal water led from the production well 1 into steam and hot water. A high temperature steam pipe 4 is connected to the upper part of the separator 3, and a high temperature hot water pipe 5 is connected to the lower part of the separator 3.

  An evaporator 7 is provided that exchanges heat with the vapor separated by the separator 3 to evaporate the working fluid (heat medium). A steam turbine 9 that is driven by the steam of the working fluid evaporated in the evaporator 7 and a generator 9a that is driven by the steam turbine 9 to generate electric power are provided.

  The steam of the working fluid that has driven the steam turbine 9 is guided to the condenser 16 via the turbine exhaust pipe 15. The condenser 16 condenses the working fluid guided from the steam turbine 9 by exchanging heat with the cooling water. Further, a cooling tower 20 for cooling the cooling water supplied to the condenser 16 is provided.

  A heating heat exchanger 23a and a preheater 23 for heating the working fluid passed through the condenser 16 are provided.

  A geothermal source (for example, steam and / or hot water) ejected from the production well 1 is supplied to the separator 3 via the geothermal source pipe 2. The separator 3 separates the high-temperature steam and high-temperature hot water. The separated high-temperature steam is used to heat the working fluid in the evaporator 7, flows in the high-temperature steam pipe 4, heats the working fluid in the evaporator 7, and then separated by the separator 3. The hot water is merged at the merge section 5a. The hot hot water and steam merged at the merge section 5a flow through the high-temperature hot water piping and are returned to the reduction well 6.

  The working fluid becomes steam in the evaporator 7 and is guided to the steam turbine 9 through the high temperature working fluid pipe 8, where the work is performed to rotate the rotating shaft 70 and drive the generator 10. The working fluid leaked from the seal portion 70a of the steam turbine has a structure that is not discharged to the outside by the extraction portion 11. The bleeder 11 is provided with an ejector 43 (see FIG. 3). The working fluid extracted by the ejector 43 (see FIG. 3) is mixed with air and supplied to the combustion chamber 13 via the transfer pipe 12. The working fluid is combusted in the combustion chamber 13, and the exhaust gas is passed through the heat exchanger 23 a for heating through the exhaust gas pipe 52 connected to the combustion chamber 13. The exhaust gas that has heated the working fluid in the heating heat exchanger 23 a is diffused into the atmosphere from the exhaust gas pipe 52.

  The steam exiting the steam turbine 9 after finishing the work is cooled and condensed in the condenser 16. The condensed working fluid passes through the low temperature working fluid piping 21 and is returned to the evaporator 7 by the pump 22. Further, a cooling water supply pipe 17 is connected to the condenser 16, and cooling water is supplied by a pump 19. The cooling water that has cooled the condenser 16 is supplied to the cooling tower 20 via the cooling water return pipe 18 to cool the cooling water.

  As shown in FIG. 4, the working fluid is heated on the low-temperature working fluid piping 21 by utilizing the exhaust heat of the working fluid (for example, hydrocarbon-based combustible substance) burned in the combustion chamber 13. A heat exchanger 23a (second preheater) is provided. The exhaust gas generated when the working fluid is burned in the combustion chamber 13 flows through the exhaust gas pipe 52 connected to the combustion chamber 13 and is passed through the heating heat exchanger 23a, and then is released to the atmosphere.

FIG. 3 is a main part schematic cross-sectional view showing the extraction part 11.
The bleeder 11 is provided with an ejector 43. The ejector 43 can create a vacuum directly from compressed air without mechanical movement of a pump or the like. In the ejector 43, the nozzle 39 and the diffuser 40 face each other at an appropriate distance, and the bundle of high-speed air 38 injected from the nozzle 39 travels toward the inlet of the diffuser 40. This air flow creates a negative static pressure, and the ejector 43 is evacuated. Due to the static pressure and the viscosity of the air, the surrounding air is drawn into the air jet that jumps into the inlet of the diffuser 40. The supplied compressed air and the mixed fluid 37 of the air and the working fluid sucked from the vacuum port pass through the diffuser 40 and are discharged from the exhaust port 41. The exhaust port 41 is connected to the transfer pipe 12 (see FIG. 4), and air and working fluid discharged from the exhaust port 41 are guided to the combustion chamber 13 (see FIG. 4).

  As shown in FIG. 3, the seal portion 70 a of the steam turbine 9 is provided with a labyrinth seal 34 between the rotor 30 side and the casing 31 side. The working fluid leaked from the labyrinth seal 34 is extracted by an ejector 43 provided in the extraction unit 11 (see FIG. 4). For example, the working fluid is flowed in the direction of the arrow 32 and the outside air is discharged in the direction of the opposite arrow 33. Washed away. Further, the working fluid and the outside air are mixed in the direction of the arrow 35 to form a mixed fluid 37 and flow into the ejector suction pipe 36.

The effects of the steam turbine having the above-described configuration and the binary power generation apparatus including the steam turbine will be described below.
The heating heat exchanger 23 a is provided between the evaporator 7 and the condenser 16. Thereby, the working fluid before being supplied to the steam turbine 9 can be heated. Thereby, since the working fluid can be efficiently heated, the turbine efficiency can be improved.

  The working fluid (for example, a hydrocarbon-based combustible substance) leaked from the seal portion 70 a of the steam turbine 9 is guided to the combustion chamber 13 by the extraction portion 11. By collecting the working fluid leaked from the seal portion 70a and burning it in the combustion chamber 13, the safety of the equipment can be improved.

  Further, for example, if the combustion is performed in the combustion chamber 13 and then released to the outside, pollution to the surrounding environment can be prevented.

  Furthermore, since the design allows the leakage of the seal portion 70a, an inexpensive seal portion such as the labyrinth seal 34 can be obtained. Therefore, the cost of equipment can be reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the steam turbine of this embodiment and the binary power generation apparatus including the same is the same as that of the first embodiment, but differs from the first embodiment in the position where the heat exchanger for heating is provided. Therefore, in this embodiment, only the structure provided with the heat exchanger for heating will be described using FIG. 2, the same components as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. .

  As shown in FIG. 2, on the high-temperature working fluid pipe 8, the working fluid is heated by using the exhaust heat of the working fluid (for example, hydrocarbon-based combustible material) burned in the combustion chamber 13. A heat exchanger 71 is provided. The exhaust gas generated when the working fluid is combusted in the combustion chamber 13 flows through the exhaust gas pipe 14 connected to the combustion chamber 13 and passes through the heating heat exchanger 71, and then is released to the atmosphere. Further, preheating for recovering the heat of the hot water at the downstream side of the junction 5a between the hot water pipe 5 through which the hot water separated from the separator 3 flows and the hot steam passed through the evaporator 7 is performed. A vessel 23 is provided. The working fluid before being supplied to the evaporator 7 flows through the preheater 23.

  According to this embodiment, the heat of the exhaust gas can be recovered by passing through the heating heat exchanger 71 that recovers heat from the exhaust gas after combustion. Thereby, the efficiency of equipment can be improved. Further, by providing the preheater 23, the working fluid can be efficiently heated. Thereby, the efficiency of an installation can be improved further.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the steam turbine of this embodiment and the binary power generation apparatus including the same is the same as that of the second embodiment, but the second embodiment has a configuration in which a preheater and a heat exchanger for heating are not provided. Is different. Therefore, only the configuration different from that of the second embodiment will be described with reference to FIG. 1, the same components as those of the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

  In FIG. 1, a steam turbine 9 that is rotated by a working fluid converted into steam by a geothermal source (for example, hot water or steam) taken out from the production well 1, and a seal portion 70 a that seals the rotating shaft 70 of the steam turbine 9. A bleed portion 11 from which the working fluid leaked from the seal portion 70a is bleed and a combustion chamber 13 in which the working fluid guided from the bleed portion 11 is combusted are provided.

  According to the present embodiment, the safety of the equipment can be improved by collecting the working fluid leaked from the seal portion 70a and burning it in the combustion chamber 13 for processing. Further, since the heating heat exchanger 71 is not provided, a simpler structure can be obtained. Since the heating heat exchanger 71 is not provided, the cost for the equipment can be reduced.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
An internal combustion engine is used instead of the combustion chamber 13 of the steam turbine of the present embodiment and the binary power generation apparatus including the steam turbine. Therefore, in the present embodiment, only the configuration in which the internal combustion engine is provided will be described using FIG. 5, the same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 5, an internal combustion engine 61 that combusts the working fluid extracted by the extraction unit 11 is provided. The internal combustion engine 61 is, for example, a combustor for the internal combustion engine 61. Moreover, you may use a boiler as a combustion chamber. The working fluid extracted from the extraction unit 11 passes through the supply pipe 60 and is supplied to the internal combustion engine 61 for combustion.

  The working fluid leaked from the seal portion 70a is supplied to an internal combustion engine 61 (for example, an engine) or a combustor such as a boiler and burned using it as fuel. Thereby, the leaked working fluid can be effectively used without waste.

DESCRIPTION OF SYMBOLS 1 Generation well 2 Geothermal source piping 3 Separator 4 High temperature steam piping 5 High temperature hot water piping 5a Junction part 6 Reducing well 7 Evaporator 8 High temperature working fluid piping 9 Steam turbine 10 Generator 11 Extraction part 12 Transfer piping 13 Combustion chamber 14 Exhaust gas piping 15 Turbine exhaust piping 16 Condenser 17 Cooling water supply piping 18 Cooling water return piping 19 Cooling water pump 20 Cooling tower 21 Low temperature working fluid piping 22 Low temperature working fluid transfer pump 23 Preheater 23a Second preheater (heat exchange for heating) vessel)
24 Working fluid piping 43 Ejector 70 Rotating shaft 70a Seal part 71 Heat exchanger for heating

Claims (7)

A steam turbine that is rotated by a combustible medium that is made into steam;
A seal portion for sealing the rotating shaft of the steam turbine;
An extraction part from which the combustible medium leaked from the seal part is extracted;
A combustion chamber in which a combustible medium guided from the bleed portion is burned;
A steam turbine comprising:   The steam turbine according to claim 1, further comprising a heat exchanger that recovers heat from the exhaust gas discharged from the combustion chamber.   The steam turbine according to claim 1, wherein the combustion chamber is a boiler or a combustor of an internal combustion engine.   The steam turbine according to claim 1, wherein an ejector is provided in the extraction part. A steam turbine according to any one of claims 1 to 4;
A separator that separates high-temperature and high-pressure geothermal water led from the production well into steam and hot water;
An evaporator for evaporating a combustible medium with the steam guided from the separator;
A generator that is driven by the steam turbine driven by steam of the combustible medium guided from the evaporator to generate electric power;
A condenser for condensing the combustible medium guided from the steam turbine;
A binary power generator characterized by comprising: A heating heat exchanger for exchanging heat between the combustion gas generated in the combustion chamber and the combustible medium;
6. The binary power generator according to claim 5, wherein the heating heat exchanger is provided on an upstream side of the steam turbine.   7. The heating heat exchanger is provided between the evaporator and the condenser and / or between the steam turbine and the evaporator. Binary power generator.

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