JP4970868B2 - Power generator - Google Patents

Description

  The present invention relates to a power generator that further drives a power generator by a drive machine (drive source) driven by steam such as a steam turbine.

  In order to link the power generation facilities to the grid, it is necessary to set the power generation frequency to a commercial frequency (50 Hz / 60 Hz). For this reason, when the commercial frequency is 60 Hz, the rotational speed of the generator is set to 3600 rpm.

  By the way, in the turbine which becomes a drive source of the generator, when the turbine is a gas turbine, the drive torque is determined by the amount of fuel gas (and air) to be supplied, and when the turbine is a steam turbine, it is supplied. The driving torque is determined by the amount of steam. The rotational speed of the generator is determined by this drive torque and the load torque on the generator side. However, even when the driving torque of the turbine is sufficiently large, the generator needs to be set to 3600 rpm as described above, so the fuel gas amount or steam amount is adjusted upstream of the turbine. An adjusting means is provided, and a speed reducer is provided on the drive shaft of the turbine.

  For example, Patent Document 1 below discloses a configuration in which a fuel flow control valve 120 that adjusts the fuel supply amount and a speed reducer 122 that decelerates the turbine rotational speed are provided, as shown in FIG. That is, the air compressed by the compressor 124 is supplied to the combustor 126 as combustion air, and the fuel is supplied to the combustor 126 via the fuel flow rate control valve 120 and combustion is performed. Combustion gas from the combustor 126 is introduced into the turbine 128 to rotationally drive the turbine 128, and the rotational speed is reduced by the speed reducer 122 provided on the drive shaft of the turbine 128 to drive the generator 130. It has become.

On the other hand, in Patent Document 2 below, as shown in FIG. 4, in a power generation apparatus using a gas turbine engine 140 as a drive source of a generator 142, power having a frequency higher than the commercial frequency is generated, and this high-frequency power is generated. Is converted to commercial frequency power by a power converter 144. That is, in this power generator, the generator 142 is configured by a generator capable of withstanding high-speed rotation, and the generator 142 is directly connected to the gas turbine engine 140, and the gas turbine engine 140 is connected at several tens of thousands rpm to several hundred thousand rpm. By driving at a rotational speed, high frequency power of about 1 kHz to 3 kHz is generated. The high-frequency power is once converted into DC power by the rectifier circuit 146, and further converted into AC output synchronized with the commercial frequency by the inverter 148 and linked to the system.
JP 2000-170548 A JP 2002-84795 A

  However, the conventional power generator has the following problems. That is, as in Patent Document 1, in the configuration in which the fuel supply amount is adjusted by the fuel flow rate control valve in order to limit the rotation speed of the generator, the amount of fuel gas introduced into the turbine is suppressed, or in some cases. There is a problem that the energy of the fuel gas and steam cannot be sufficiently utilized because the air is wasted. In addition, since the reduction gear 122 that decelerates the turbine rotation speed is provided in the one of Patent Document 1, mechanical loss in the reduction gear 122 is unavoidable. Further, when the reduction gear 122 is provided, there is a problem that labor is required for maintenance.

  On the other hand, in Patent Document 2, since the generator 142 can be operated at high speed rotation, fuel gas can be fully utilized, and since the generator 142 is directly connected to the gas turbine engine 140, the mechanical loss here is reduced. It does not occur. However, the gas turbine engine 140 is configured to be driven at a high rotational speed of several tens of thousands rpm to several hundred thousand rpm, and the generator 142 is directly connected to the gas turbine engine 140. Heat generation becomes a problem, and it is difficult to continue operation at a high rotational speed.

  Therefore, the present invention has been made in view of such a point, and the object of the present invention is to enable steam generators to be used effectively by allowing the generator to continue operation at a high rotational speed. It is in.

In order to achieve the above object, the present invention is based on the assumption that the generator has a drive device driven by steam, and generates power by driving the generator with this drive device. Cooling that is constituted by a machine and that is coupled to the drive machine without a reduction gear, and that cools the generator and lubricates a bearing that rotatably supports the rotating shaft of the generator. And a frequency converter that converts the electric power generated by the generator into electric power of a commercial frequency and outputs the electric power, and the cooling means is installed below the generator and a tank that stores the oil; A cooler for cooling the oil and a pump for pumping the oil are provided to circulate the oil, and the circulation path is a cooling provided in a body portion of the casing of the generator Ream On the other hand, through the oil supply hole formed in the upper end portion of the casing of the generator, the bearing supporting the shaft of the generator, the inside of the casing, and the communication path formed in the lower end portion of the casing, It is configured to flow down to the tank .

In the present invention, since the electric power generated by the generator is converted into electric power of the commercial frequency by the frequency converter, the situation where the rotational speed of the generator must be limited to generate power at a predetermined frequency is avoided. be able to. As a result, it becomes possible to drive the driving machine at a rotational speed corresponding to the flow rate of the steam supplied to the power generation device, and it becomes possible to use the steam without waste. Furthermore, since the generator is composed of a permanent magnet synchronous generator, high-efficiency power generation is possible in the high-speed rotation region, and the drive machine and the generator are directly connected without a reduction gear. Therefore, there is no mechanical loss here, which also contributes to the improvement of power generation efficiency. Furthermore, since the generator is composed of a permanent magnet synchronous generator and oil for cooling the generator is circulated, heat generation of the generator can be efficiently suppressed. For this reason, the generator can be continuously operated at a high rotational speed. In addition, it is preferable that the said drive machine is a steam turbine. Alternatively, the driving machine is preferably a screw expander. Further, in this configuration, since the oil is circulated while cooling, the generator can be cooled without consuming a large amount of oil. In addition, since the amount of oil circulation can be adjusted by driving the pump, the generator can be properly cooled. Further, in this configuration, the circulation path is communicated with a cooling path provided in the body of the casing of the generator, and oil is circulated through the casing body of the generator to cool the generator. The generator can be efficiently cooled.

  Here, if the said generator is comprised by the internal permanent magnet synchronous generator, the emitted-heat amount in a generator can be suppressed more.

Before SL cooling passage may be with the bored in the body portion of the casing in the circumferential direction and axial configuration. In this configuration, oil can be evenly distributed in the body of the casing, so that the generator can be cooled without unevenness.

  In addition, an introduction pipe connected to the inlet side of the driving machine and a discharge pipe connected to the outlet side of the driving machine are provided, and the introduction pipe and the discharge pipe are steam generated by steam generating means. Can be connected to a main pipe that leads to a steam utilization facility, and by connecting the introduction pipe and the discharge pipe to the main pipe, the steam flowing through the main pipe flows into the introduction pipe and enters the driving machine. Steam introduced and discharged from the drive is preferably returned to the main pipe through the discharge pipe.

  In this configuration, since power generation can be performed using the steam before being introduced into the steam utilization facility, the utilization efficiency of the steam generated by the steam generation means can be increased. This is particularly effective when connecting to a main pipe connected to a steam utilization facility where low-pressure steam is used.

  As described above, according to the present invention, the drive unit can be driven at the number of rotations corresponding to the flow rate of the steam supplied to the power generation device, and the heat generation of the generator can be suppressed. Operation can be continued at the rotational speed. Therefore, steam energy can be used effectively.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a power generator 20 according to the present invention. As shown in the figure, the power generation device 20 generates power using steam energy generated by the steam generation means 10 and used by the steam utilization facility 12. This will be specifically described below.

  The steam generation means 10 and the steam utilization facility 12 are connected by a main pipe 14 through which steam flows. The main pipe 14 is provided with a pressure reducing valve 16.

  The steam generation means 10 is constituted by a plurality of boilers 10 a connected in parallel to the main pipe 14. Each of these boilers 10a has a steam generation amount of, for example, about 2 tons / hour, and each of the boilers 10a is constituted by, for example, a small once-through boiler.

  The steam utilization facility 12 is, for example, a water heater, a heater, a bath facility, a dryer, a cleaning facility, a kitchen device, a sterilizer, or the like that uses, for example, steam at about 150 to 200 ° C.

  The power generation apparatus 20 according to this embodiment includes a steam turbine 22, a generator 24, a frequency converter 26, a controller 28, a cooling means 30, and the like, which are housed in a casing 32. The casing 32 is provided with a ventilation fan 34.

  The steam turbine 22 is constituted by, for example, an axial flow turbine. The steam turbine 22 is selected so that the maximum rotation speed obtained from the maximum supply amount of the target steam is within the range of the allowable rotation speed.

  The steam turbine 22 is provided with an introduction pipe 36 connected to the inlet side of the steam turbine 22 and an exhaust pipe 38 connected to the outlet side of the steam turbine 22. The introduction pipe 36 is connected to the upstream side of the pressure reducing valve 16 in the main pipe 14, and the discharge pipe 38 is connected to the downstream side of the pressure reducing valve 16 in the main pipe 14. Thereby, at least a part of the steam generated by the steam generating means 10 is introduced into the steam turbine 22, and the steam discharged from the steam turbine 22 is returned to the main pipe 14.

  The introduction pipe 36 is provided with an on-off valve 40, a drain separator 42, a flow rate adjustment valve 44 and an emergency shut-off valve 46 in order from the upstream side. The on-off valve 40 is disposed in the vicinity of the connection portion with the main pipe 14. The drain separator 42 is for separating the drain from the steam flowing through the introduction pipe 36. The flow rate adjusting valve 44 adjusts the flow rate of the steam flowing through the introduction pipe 36 and is configured to be open / close controlled by the controller 28. The emergency shut-off valve 46 completely shuts off the introduction pipe 36 and can be controlled by the controller 28.

  An opening / closing valve 50 is provided in the vicinity of the connection portion of the discharge pipe 38 with the main pipe 14. The on-off valve 50 and the on-off valve 40 of the introduction pipe 36 constitute switching means for switching whether to introduce the steam flowing through the main pipe 14 into the introduction pipe 36. That is, when the steam generated by the steam generation means 10 is directly introduced to the steam utilization facility 12, the on-off valves 40 and 50 are closed, and when the power generation using steam is performed, the on-off valves 40 and 50 are opened. The on-off valves 40 and 50 can be constituted by either an on-off valve that can be switched between a fully open state and a fully closed state, or an on-off valve that can be adjusted in opening. Further, as the switching means, a three-way switching valve may be provided in place of the on-off valves 40 and 50. In this case, the three-way switching valve is arranged at the connection between the main pipe 14 and the introduction pipe 36 and at the connection between the main pipe 14 and the discharge pipe 38.

  The introduction pipe 36 is provided with a pressure sensor 52 that detects the pressure of the steam introduced into the steam turbine 22. The exhaust pipe 38 is provided with a pressure sensor 56 that detects the pressure of the steam exhausted from the steam turbine 22.

  A rotating shaft 60 of the generator 24 is coupled to a driving shaft 64 of the steam turbine 22 via a coupling 62. That is, the rotating shaft 60 of the generator 24 is connected to the drive shaft 64 of the steam turbine 22 without using a speed reducer. For this reason, the operating rotational speed of the generator 24 is the same as the rotational speed of the steam turbine 22.

  The electric power generated by the generator 24 is introduced into the frequency converter 26. The frequency converter 26 converts the frequency of the electric power generated by the generator 24. For example, the frequency converter 26 converts electric power of 10 to 100 Hz into electric power of a commercial frequency of 60 Hz. A pulse generator 66 is provided on the rotating shaft 60 of the generator 24, and the frequency converter 26 performs switching control of internal elements in accordance with an output value from the pulse generator 66 to convert from AC to DC. The DC power is converted into a desired frequency, that is, commercial frequency power, and output. The electric power output from the frequency converter 26 is linked to the system 70 through the transformer 68.

  The controller 28 derives an appropriate rotational speed based on detection signals from the pressure sensors 52 and 56. That is, since it can be approximated that the steam flow rate and the appropriate rotation speed are in a substantially linear relationship, the steam turbine 22 is supplied from the detection values of the pressure sensors 52 and 56 provided on the upstream side and the downstream side of the steam turbine 22. The steam flow rate is derived, and an appropriate rotational speed is derived based on the steam flow rate. The frequency converter 26 outputs a rotation speed control signal to the generator 24 based on the appropriate rotation speed derived by the controller 28. Thereby, the generator 24 is drive | operated by the appropriate rotation speed according to a steam flow rate.

  The cooling means 30 is for cooling the generator 24 and includes a circulation path 72 through which the coolant circulates. The circulation path 72 is provided with a coolant tank 74, a pump 75, and a cooler 76. The coolant tank 74 is for storing coolant. The pump 75 is for pumping the coolant in the coolant tank 74, and the coolant circulates in the circulation path 72 by driving the pump 75. The cooler 76 is for cooling the coolant introduced into the generator 24. The cooler 76 is provided with a cooling water passage 76a through which the cooling water flows, and the cooling water passage 76a. Cool the coolant with cooling water flowing through For example, oil is used as the cooling liquid.

  As shown in FIG. 2, the generator 24 includes a generator casing 80 having a barrel portion 80a formed in a substantially cylindrical shape and end wall portions 80b provided at both ends of the barrel portion 80a. The body 80a is installed on the coolant tank 74 so that the axial direction of the body 80a is horizontal. Cylindrical boss portions 80c projecting inward are provided on both end wall portions 80b of the generator casing 80, and the rotary shaft 60 passes through both boss portions 80c. The boss portion 80c is provided with a bearing 82, and the rotary shaft 60 is rotatable.

  The rotary shaft 60 is disposed so as to extend in the horizontal direction, extends outward from one boss portion 80 c (left side in FIG. 2), and is coupled to the drive shaft 64 of the steam turbine 22 via the coupling 62. Has been.

The end wall portion 80b of the generator casing 80 is formed with an oil supply hole 80d extending from the upper end portion of the generator casing 80 into the boss portion 80c. Lubricating oil is supplied to the bearing 82 through the oil supply hole 80d. A shaft sealing portion 84 is provided on the boss portion 80c outside the bearing 82 in the axial direction so that the lubricating oil of the bearing 82 does not leak out of the casing. On the other hand, a communication passage 88 is provided at the lower end portion of the generator casing 80 so as to communicate the inside of the generator casing 80 and the upper opening 86 of the coolant tank 74, and flows out from the boss portion 80 c into the generator casing 80. The lubricated oil flows down into the cooling tank 74 through the communication path 88. That is, the lubricating oil that has the same ones used oil which is used as a coolant.

  The generator 24 is constituted by an internal permanent magnet synchronous generator (IPM). That is, the stator 90 is fixed to the trunk portion 80 a of the generator casing 80, and the rotor 91 is provided on the inner peripheral side of the stator 90. A permanent magnet (not shown) is fitted inside the rotor 91, and the rotor 91 is fixed to the rotating shaft 60. The generator 24 is selected so that the maximum rotational speed of the steam turbine 22 is within the allowable rotational speed range.

  A coil 93 is wound around the stator 90, and the coil 93 is connected to the electrical component port 95. The electrical component port 95 is connected to a wiring connected to the frequency converter 26. The coil 93 is provided with a temperature sensor (not shown). The temperature sensor is connected to the electrical port 96. Wires connected to the controller 28 are connected to the electrical port 96.

  The trunk portion 80a of the generator casing 80 is provided with an inlet port 98 and an outlet port 99. The inlet port 98 and the outlet port 99 are communicated with each other by a cooling path 100 formed in the trunk portion 80a. Yes. The inlet port 98 is provided on one side of the trunk portion 80a, and the end of the circulation path 72 on the cooler 76 side is connected. On the other hand, the outlet port 99 is provided on the other side of the trunk portion 80a, and the end of the circulation path 72 on the coolant tank 74 side is connected.

  The cooling path 100 is arranged at intervals in the axial direction and has a plurality of circumferential portions 100a extending in the circumferential direction in the body portion 80a, and an axial direction portion extending in the axial direction so as to communicate these circumferential portions 100a. 100b. Then, the coolant introduced through the inlet port 98 flows through the circumferential portion 100a and the axial portion 100b toward the outlet port 99. Thereby, the trunk | drum 80a of the generator casing 80 is cooled evenly.

  Here, the operation of the power generation device 20 will be described. The steam generated by driving each boiler 10 a flows through the main pipe 14, is decompressed by the decompression valve 16, and is then introduced into the steam utilization facility 12. When power generation is performed, the on-off valve 40 of the introduction pipe 36 and the on-off valve 50 of the discharge pipe 38 are opened, whereby a part of the steam generated in each boiler 10a and flowing through the main pipe 14 is introduced. It is diverted to the pipe 36. Even in this case, since the steam is sent to the steam utilization facility 12, the steam can be utilized in the steam utilization facility 12.

  The steam turbine 22 is driven by the steam diverted to the introduction pipe 36, and the rotating shaft 60 of the generator 24 rotates accordingly, and electric power is generated. At this time, the flow rate of steam supplied to the steam turbine 22 is derived by the pressure sensors 52 and 56, and the appropriate number of revolutions under this steam flow rate is derived by the controller 28. And the generator 24 is drive | operated with this appropriate rotation speed. The steam that has driven the steam turbine 22 is merged with the steam flowing through the main pipe 14 through the discharge pipe 38 and supplied to the steam utilization facility 12. That is, even when the amount of steam used in the steam utilization facility 12 is reduced, the steam can be used for power generation by opening the on-off valves 40 and 50, so that each boiler 10a is always operated in a state close to the maximum capacity. It is possible to do. For this reason, since each boiler 10a can be driven stably, the efficiency in the boiler 10a can be improved.

  During operation of the generator 24, the temperature in the generator 24 is detected by a temperature sensor (not shown), and the coolant circulates in the circulation path 72. That is, the cooling liquid in the cooling liquid tank 74 is sent out by driving the pump 75, is cooled by the cooling water in the cooling water passage 76 a in the cooler 76, and the cooled cooling liquid is introduced into the generator 24. Then, the coolant flows through the circumferential portion 100a and the axial portion 100b of the cooling path 100 via the inlet port 98, and cools the trunk portion 80a of the generator casing 80 evenly. Thereby, the heat_generation | fever of the generator 24 can be suppressed efficiently. The coolant flowing through the cooling path 100 flows through the circulation path 72 via the outlet port 99 and returns to the cooling liquid tank 74. The coolant continues this circulation.

  The electric power generated by the generator 24 is output to the frequency converter 26 through the electric equipment port 95. The frequency of this power is, for example, 10 to 100 Hz. This power is converted into commercial frequency power by the frequency converter 26 and output, and is linked to the system 70 through the transformer 68.

  As described above, according to the present embodiment, the electric power generated by the generator 24 is converted into the electric power of the commercial frequency by the frequency converter 26. Therefore, the rotation of the generator 24 to generate power at a predetermined frequency is performed. The situation where the number must be limited can be avoided. As a result, it becomes possible to drive the steam turbine 22 at a rotational speed corresponding to the flow rate of the steam supplied to the power generation apparatus 20, and thereby the steam can be used without waste. Furthermore, since the generator 24 is composed of a permanent magnet synchronous generator, high-efficiency power generation is possible in the high-speed rotation region, and the steam turbine 22 and the generator 24 are directly connected without using a reduction gear. Therefore, there is no mechanical loss here, which also contributes to the improvement of power generation efficiency. Furthermore, since the generator 24 is constituted by a permanent magnet synchronous generator and the coolant for cooling the generator 24 is circulated, the heat generation of the generator 24 can be efficiently suppressed. For this reason, the generator 24 can be continuously operated at a high rotational speed.

  Furthermore, in this embodiment, since the generator 24 was comprised with the internal permanent magnet synchronous generator, the emitted-heat amount in the generator 24 can be suppressed more.

  Further, in the present embodiment, since the coolant is circulated while being cooled, the generator 24 can be cooled without consuming a large amount of the coolant, and the coolant is circulated by driving the pump 75. Since the amount can be adjusted, the generator 24 can be properly cooled.

  Further, in the present embodiment, since the coolant circulation path 72 is communicated with the cooling path 100 provided in the trunk portion 80a of the generator casing 80, the generator 24 can be efficiently cooled. Moreover, since the cooling path 100 has a structure in which the body 80a of the generator casing 80 is perforated in the circumferential direction and the axial direction, the coolant can be evenly distributed in the body 80a. The machine 24 can be cooled evenly.

  Moreover, in this embodiment, since it can generate electric power using the steam before introduce | transducing into the steam utilization equipment 12, the utilization efficiency of the steam produced | generated with the boiler 10a can be improved. In particular, it is effective when connecting to the main pipe 14 connected to the steam utilization facility 12 in which low-pressure steam is used.

  In the present embodiment, the steam turbine 22 is configured by an axial turbine, but instead, the steam turbine 22 may be configured by a radial turbine. Further, in the present invention, any fluid machine that can obtain a rotational force from the flow of steam can be used as the drive machine for driving the generator. Examples of such a fluid machine include a screw expander in addition to the above-described turbine. Therefore, in the form of FIG. 1, the steam turbine 22 may be replaced with a screw expander.

It is a figure showing roughly the whole composition of the power generator concerning the embodiment of the present invention. It is sectional drawing which shows the generator and cooling fluid tank which were provided in the said electric power generating apparatus. It is a figure which shows the structure of the conventional electric power generating apparatus. It is a figure which shows the structure of the conventional electric power generating apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Steam production | generation means 12 Steam utilization equipment 14 Main piping 20 Power generator 22 Steam turbine 24 Generator 26 Frequency converter 30 Cooling means 36 Introducing pipe 38 Discharge pipe 72 Circulation path 74 Coolant tank (tank)
75 Pump 76 Cooler 80 Generator casing (casing)
80a Body 100 Cooling path

Claims (6)

A power generator that has a drive machine driven by steam and generates power by driving a generator by the drive machine,
The generator is constituted by a permanent magnet synchronous generator, and is connected without the drive unit and the reduction gear,
Cooling means for cooling the generator and circulating oil for lubricating a bearing that rotatably supports the rotating shaft of the generator, and converting the electric power generated by the generator into electric power of a commercial frequency and outputting it A frequency converter ,
The cooling means is connected to a tank that is installed below the generator and stores the oil, a cooler that cools the oil, and a pump that pumps the oil, and a circulation path through which the oil circulates. Prepared,
The circulation path is in communication with a cooling path provided in a body portion of the generator casing, while the oil is provided with an oil supply hole formed in an upper end portion of the generator casing, and a shaft of the generator. The power generator is configured to flow down to the tank through a bearing that supports the inside of the casing, and further through a communication passage formed in a lower end portion of the casing .   The power generator according to claim 1, wherein the driving machine is a steam turbine.   The power generator according to claim 1, wherein the driving machine is a screw expander.   The power generator according to claim 1, wherein the generator is configured by an internal permanent magnet synchronous generator. The power generation device according to claim 1 , wherein the cooling path is configured to be perforated in a circumferential direction and an axial direction in a body portion of the casing. An introduction pipe connected to the inlet side of the driving machine and a discharge pipe connected to the outlet side of the driving machine are provided;
The introduction pipe and the discharge pipe are configured to be connectable to a main pipe that guides the steam generated by the steam generation means to the steam utilization facility,
By connecting the introduction pipe and the discharge pipe to the main pipe, steam flowing through the main pipe flows into the introduction pipe and is introduced into the driver, and the steam discharged from the driver is discharged into the discharge pipe. generator according to any one of claims 1 to 5, characterized in that it is returned to the main pipe through.

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