JP2014020337A - Turbine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain ammonia gas from being leaked to outside of a machine.SOLUTION: A turbine generator comprises: a casing 101; a rotary shaft 110 arranged to extend in a longitudinal direction of the casing 101 in the casing 101; a pair of carbon bearings 111a, 111b rotatably supporting the rotary shaft 110, and spaced from each other in a rotation axis direction of the rotary shaft 110; a turbine impeller 112 fixed to one end of the rotary shaft 110 and rotating according to supply of ammonia gas; and a power generator 23 connected to the other end of the rotary shaft 110 and generating power according to the rotation of the rotary shaft 110. A space S formed by inner walls 101a, 101b of the casing 101, the rotary shaft 110, and the pair of carbon bearings 111a, 111b is filled with cooling water.

Description

  The present invention relates to a turbine generator having a turbine impeller that rotates by receiving ammonia gas, and that generates electric power by the rotational force of the turbine impeller.

  Conventionally, a binary power generation system that generates power by boiling ammonia having a boiling point lower than that of water and rotating a turbine impeller using the generated ammonia gas is known (see Patent Document 1). According to this binary power generation system, it is possible to use a heat source that was previously considered unsuitable for power generation at a relatively low temperature, such as hot wastewater from an incinerator, exhaust gas from a heating furnace, hot springs, steam, etc. In addition, energy saving can be realized.

JP 2009-221961 A

  In the conventional binary power generation system, ammonia gas leaks out of the machine through the gap between the rotating part and the non-rotating part due to the pressure difference between the rotating part and the non-rotating part of the turbine generator. there is a possibility. For this reason, in the conventional binary power generation system, ammonia gas is prevented from leaking out of the apparatus by providing a mechanical seal member between the rotating part and the non-rotating part of the turbine generator. However, in the binary power generation system, since the turbine impeller rotates at a high speed, the pressure difference between the rotating part and the non-rotating part becomes very large, and even if a mechanical seal member is provided, ammonia gas leaks out of the machine. There was a thing. From the above, it has been expected to provide a technique capable of more reliably suppressing ammonia gas from leaking out of the apparatus.

  This invention is made | formed in view of the said subject, The objective is to provide the turbine generator which can suppress that ammonia gas leaks out of an apparatus.

  In order to solve the above problems and achieve the object, a turbine generator according to the present invention includes a casing, a rotating shaft disposed in the casing so as to extend in a longitudinal direction of the casing, and the rotating shaft. A pair of carbon bearings that are rotatably supported and spaced apart in the direction of the rotation axis of the rotary shaft, and rotate according to the supply of ammonia gas fixed to one end of the rotary shaft A turbine impeller and a generator that is connected to the other end of the rotating shaft and that generates electric power according to the rotation of the rotating shaft. The inner wall surface of the casing, the rotating shaft, and the pair of carbon bearings The space formed by is filled with cooling water.

  In the above invention, the turbine generator according to the present invention is disposed on the peripheral side of the rotating shaft between the carbon bearing disposed on the turbine impeller side and the turbine impeller, and on the generator side. A mechanical seal member disposed on a peripheral portion of the rotating shaft between the carbon bearing and the generator is provided.

  According to the turbine generator according to the present invention, ammonia gas can be prevented from leaking out of the apparatus.

FIG. 1 is a block diagram showing a configuration of an incineration system including a binary power generation system according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a configuration of the turbine shown in FIG.

  Hereinafter, a configuration of an incineration system including a binary power generation system according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of incineration system]
First, the configuration of an incineration system including a binary power generation system according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a block diagram showing a configuration of an incineration system including a binary power generation system according to an embodiment of the present invention. As shown in FIG. 1, an incineration system 1 including a binary power generation system according to an embodiment of the present invention includes an incinerator 2, a boiler 3, a dust collector 4, a flue gas treatment tower 5, a steam power generation system 10, and a binary power generation system. A power generation system 20 is provided. The incinerator 2 incinerates incineration objects such as sludge. The incinerator 2 burns the incineration object using the air supplied from the blower 6 and the fuel supplied as necessary, and outputs a high-temperature combustion gas of, for example, about 850 ° C. to the boiler 3. The incinerator 2 is realized by a fluidized incinerator, a circulating incinerator, or the like, but may be realized by other incineration methods.

  The boiler 3 functions as a heat source for the steam power generation system 10. The dust collector 4 removes combustion ash from the combustion gas of the combustion furnace 2 sent through the boiler 3, and sends the combustion gas from which the combustion ash has been removed to the flue gas treatment tower 5. The temperature of the combustion gas sent from the boiler 3 is about 250-300 degreeC, for example. The flue gas treatment tower 5 supplies normal temperature water, lowers the temperature of the combustion gas sent from the dust collector 4 to, for example, about 40 to 50 ° C., and blows the combustion gas from a chimney (not shown) via the blower 7. Release into the atmosphere. The heat of the high temperature waste water out of the water exchanged by the flue gas treatment tower 5 is used in the binary power generation system 20.

  The steam power generation system 10 is a system that generates electricity by driving the steam turbine ST by a Rankine cycle using water as a medium, using the combustion gas of the boiler 3 as a heat source, and driving a generator 14 coupled to the steam turbine ST. . The boiler 3 heats the circulating water to convert it into steam, and sends the converted steam in a high-temperature and high-pressure state to the steam header 11. The steam header 11 is a steam header, temporarily accumulates water vapor from the boiler 3, and distributes it to each pipe. Although a plurality of pipes are not shown in FIG. 1, pipes that supply water vapor to a system other than the water vapor power generation system 10 are combined.

  The steam header 11 supplies water vapor to the high-pressure steam sump 12. The high-pressure steam sump 12 corresponds to the work amount of the steam turbine ST, supplies necessary steam to the steam turbine ST to drive the steam turbine ST, and sends excess steam to the high-pressure condenser 13 to supply steam. to keep balance. For example, the high-pressure steam sump 12 has a high-pressure condenser 13 when the steam turbine ST is in a low load state or when more steam than the steam amount required by the steam turbine ST is supplied from the boiler 3 side. Return water vapor to the side.

  The steam turbine ST is driven when high-temperature and high-pressure steam supplied from the high-pressure steam sump 12 is input to the inlet, and drives the generator 14 to generate power. Worked low-temperature and low-pressure steam (preheated steam) is discharged from the outlet of the steam turbine ST. This residual heat steam is input to the low-pressure condenser 15 via the regulating valve 10a, but a part of the residual heat steam is provided along with the regulating valve 10a in the middle of the piping branched from the steam turbine ST side of the regulating valve 10a. The control valve 10b and the control valve 10c provided in the middle of the piping that joins from the low pressure condenser 15 side of the control valve 10a are used to supply the heat exchange device 22 of the binary power generation system 10. The three regulating valves 10a to 10c are flow regulating valves, and distribute the flow of the remaining heat steam discharged from the steam turbine ST outlet to the low pressure condenser 15 side and the binary power generation system 20 side. For example, when the load of the steam turbine ST is low, the three regulating valves 10a to 10c increase the supply flow rate to the binary power generation system 20 so that the binary power generation system 20 can perform stable power generation.

  The low pressure condenser 15 lowers the temperature of the residual heat steam by the cooling water generated by the cooling pump 15a and the cooling device 15b, and condenses it. By this condensation, the outlet side of the steam turbine ST becomes a negative pressure state, and the conversion efficiency of the steam turbine ST can be increased. The remaining heat steam circulated through the regulating valves 10b, 10c is also heat-exchanged by the heat exchange device 22, and the remaining heat steam is lowered in temperature. For this reason, the condensing capacity of the low-pressure condenser 15 is smaller than that of the conventional one, and the configuration of the low-pressure condenser 15 can be simplified. Furthermore, the cooling capacity and configuration of the cooling pump 15a and the cooler 15b can be small. In addition, the amount of residual heat that was discarded in the low-pressure condenser 15 can be reduced, and a part of the residual heat that was discarded in the conventional low-pressure condenser 15 can be used in the binary power generation system 20.

  That is, a part of the heat energy discarded in the conventional low-pressure condenser 15 can be effectively used in the binary power generation system 20, and the cooling pumps 15 a and 15 b that realize the condensing capacity of the low-pressure condenser 15. Since the drive energy is reduced, the energy efficiency of the entire system is synergistically improved. Furthermore, even when the remaining heat steam output from the steam turbine ST of the steam power generation system 10 is in a relatively high temperature state, the flow rate of the remaining heat steam to the low pressure condenser 15 side and the flow rate to the heat exchange device 22 side. Therefore, the condensate treatment of the remaining heat steam and the utilization processing of the remaining heat can be performed in a well-balanced manner.

  The condensate tank 16 stores the water supplied from the low-pressure condenser 15 and the water supplied from the high-pressure condenser 13 via the pump 16a, and is sent to the deaerator 17 via the pump 16b. The The pressure balance of the condensate tank 16 is achieved by controlling the driving of the pumps 16a and 16b. The deaerator 17 further heats the input condensate and removes air such as oxygen dissolved in the water. When the deaerator 17 removes air, corrosion of the boiler 3 and piping can be prevented. The depressurization and temperature reduction device 18 depressurizes and reduces the water vapor stored in the high-pressure steam sump 12 and stores it in the low-pressure steam sump 19, and the deaerator 17 heats using the water vapor in the low-pressure steam sump 19, The water dissolved in water is removed by once volatilizing and re-condensing the water. The degassed water is supplied again to the boiler 3 and circulates through the Rankine cycle of the steam power generation system 10.

  The binary power generation system 20 is a system that is cascade-connected to the steam power generation system 10 and drives the turbine 100 by a Rankine cycle using a medium having a boiling point lower than that of water, and drives a generator 23 coupled to the turbine 100. It is a system that generates electricity by doing. The reason for using a low boiling point medium is that high-pressure steam can be easily obtained with a low-temperature heat source called residual heat steam. This low-boiling medium is ammonia. Ammonia is a colorless and transparent low-boiling medium that naturally exists in nature, and its evaporation temperature is -33.3 ° C., 4.0 MPa, 79.6 ° C. under air, and has good thermophysical properties. The global warming potential is zero and the ozone depletion potential is zero.

  The binary power generation system 20 includes a heat exchange device 22 that performs heat exchange between residual heat steam supplied from the steam power generation system 10 side and a medium having a boiling point lower than that of water. In addition, a heat exchange device 21 that performs heat exchange between the high-temperature wastewater supplied from the flue gas treatment tower 5 and the low-boiling point medium may be disposed in the front stage of the heat exchange device 22. By using the high temperature waste water supplied from the smoke treatment tower 5, the energy efficiency of the entire incineration system 1 can be further increased.

  Ammonia, which is a low-boiling point medium supplied by the pump 25, easily becomes ammonia gas through the heat exchange devices 21 and 22, and this high-pressure ammonia gas is supplied to the inlet of the turbine 100 to drive the generator 23. Do the job you want. The worked ammonia gas is discharged from the outlet of the turbine 100 and input to the condenser 24 to convert the ammonia gas into an ammonia liquid and circulate through the pump 25. By introducing the steam extracted from the low-pressure steam sump 19 to the steam heater 35, the low-boiling-point medium steam can be superheated and the efficiency can be improved.

[Configuration of turbine]
Next, the configuration of the turbine 100 will be described with reference to FIG.

  FIG. 2 is a cross-sectional view illustrating a configuration of a turbine according to an embodiment of the present invention. As shown in FIG. 2, a turbine 100 according to an embodiment of the present invention includes a casing 101 and a turbine body 102 accommodated in the casing 101. The turbine body 102 has a rotating shaft 110. The rotary shaft 110 is disposed in the casing 101 so as to extend in the longitudinal direction of the casing 101, and is rotatably supported by two carbon bearings (slide bearings) 111a and 111b that are spaced apart in the rotational axis direction. Has been.

  A disc-shaped turbine impeller 112 is fixed to one end of the rotating shaft 110. The disc-shaped turbine impeller 112 is fixed to one end of the rotating shaft 110 in a state where the axis of the disc-shaped turbine impeller coincides with the axis of the rotating shaft 110. In the vicinity of the turbine impeller 112, a plurality of blowing nozzles 113 extending in the radial direction of the turbine impeller 112 are arranged. The plurality of blowing nozzles 113 are arranged at intervals in the circumferential direction of the turbine impeller 112. The turbine impeller 112 rotates by receiving ammonia gas injected from the plurality of outlet nozzles 113, and the rotating shaft 110 rotates in accordance with the rotation of the turbine impeller 112.

  The other end of the rotating shaft 110 is fixed to a rotor (not shown) of the generator 23. In the generator 23, the rotor (not shown) generates a rotating magnetic field by rotating the rotating shaft 110, and an induced voltage is generated in the coil of the stator core by the rotating magnetic field. Thus, the generator 23 converts the rotational power output from the turbine 100 into electric power and outputs it.

  The peripheral portion of the rotating shaft 110 between the carbon bearing 111a and the turbine impeller 112 disposed on the turbine impeller 112 side, and between the carbon bearing 111b and the generator 23 disposed on the generator 23 side. Mechanical seal members 114a and 114b for suppressing ammonia gas from leaking out of the apparatus are disposed at the peripheral portions of the rotary shaft 110, respectively. Cooling water is circulated and supplied to the space S formed by the rotating shaft 110, the carbon bearings 111a and 11b, and the inner wall surfaces 101a and 101b of the casing 101, and the space S is always filled with the cooling water.

  According to such a configuration, even if ammonia gas leaks from the mechanical seal member 114a, the ammonia gas dissolves in the cooling water filling the space S, so that the ammonia gas leaks out of the machine. Can be suppressed. Further, since the carbon bearings 111a and 11b have ammonia resistance, the carbon bearings 111a and 11b are not corroded by ammonia. Further, since the carbon bearings 111a and 11b are always in contact with the cooling water, the cooling water suppresses the carbon bearings 111a and 111b from generating heat as the rotating shaft 110 rotates, and the carbon bearings 111a and 111b are worn by heat. Can be prevented.

  The embodiment to which the invention made by the present inventors is applied has been described above, but the present invention is not limited by the description and the drawings that constitute a part of the disclosure of the present invention. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

23 Generator 100 Turbine 101 Casing 102 Turbine body 110 Rotating shaft 111a, 111b Carbon bearing 112 Turbine impeller 113 Blowing nozzle 114a, 114b Mechanical seal member

Claims (2)

A casing,
A rotating shaft disposed in the casing so as to extend in a longitudinal direction of the casing;
A pair of carbon bearings that rotatably support the rotating shaft and that are spaced apart in the direction of the rotating shaft of the rotating shaft;
A turbine impeller fixed to one end of the rotating shaft and rotating in response to the supply of ammonia gas;
A generator that is connected to the other end of the rotating shaft and that generates electricity in accordance with the rotation of the rotating shaft;
A turbine generator, wherein a space formed by an inner wall surface of the casing, the rotary shaft, and the pair of carbon bearings is filled with cooling water.   The peripheral portion of the rotating shaft between the carbon bearing disposed on the turbine impeller side and the turbine impeller, and the rotating shaft between the carbon bearing disposed on the generator side and the generator. The turbine generator according to claim 1, further comprising a mechanical seal member disposed at a peripheral portion.

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