Method for operating power generation facility, power generation system, and apparatus for operation control

Abstract

To smoothly start up a power generation facility.SOLUTION: A method for operating a power generation facility 10 has: a supply process (S12) of, in the state that a supply control valve 511 and an exhaust control valve 521 are closed and an intake control valve 541 is open, supplying a gas, which is taken in through an intake branch 54 and is pressurized to a pressure higher than an atmospheric pressure by a scroll expander 2 by operating the scroll expander 2 as a compressor, to steam supply piping 51 and an exhaust branch 52; and a discharge process (S13) of discharging the gas from the steam supply piping 51 and the exhaust branch 52 by opening the exhaust control valve 521.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an operation method of a power generation facility, a power generation system, and an operation control device.

Background Art

[0002] Patent Documents 1 to 4 disclose a power generation facility including a generator that generates power according to the driving force received from an expander. The expander is a so-called scroll expander having a pair of scrolls formed in a spiral shape. The scroll expander receives steam and converts the expansion of the steam into a rotational motion. The rotational motion is provided to the generator, and the generator generates electric power.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] The power generation facility can mutually switch between a standby state in which power is not generated and a power generation state in which power is generated according to the demand for power. It is desirable that the switching from the standby state to the power generation state be performed smoothly.

[0005] An object of the present invention is to provide an operation method of a power generation facility, a power generation system, and an operation control device that can smoothly start up the power generation facility.

Means for Solving the Problems

[0006] One embodiment of the present invention is a method for operating a power generation facility, comprising a rotating machine having a coil and a magnet, a fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, a first medium pipe connected to a first input / output part of the fluid machine and provided with a supply control valve, a second medium pipe connected to a second input / output part of the fluid machine, an exhaust pipe connected between the supply control valve and the first input / output part in the first medium pipe and provided with an exhaust control valve, and an intake pipe connected to the second medium pipe and provided with an intake control valve. The method for operating the power generation facility includes a supply step of operating the fluid machine as a compressor with the supply control valve and the exhaust control valve closed and the intake control valve open, thereby supplying a gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than atmospheric pressure to the first medium pipe and the exhaust pipe, and a discharge step of discharging the gas inside the first medium pipe and the exhaust pipe from the exhaust pipe by opening the exhaust control valve.

[0007] The method for operating the power generation facility supplies a gas pressurized to a pressure higher than atmospheric pressure to the first medium pipe and the exhaust pipe by implementing the supply step. When the exhaust control valve provided in the exhaust pipe is opened in the first medium pipe and the exhaust pipe in a state where a gas pressurized to a pressure higher than atmospheric pressure is supplied, the gas inside the first medium pipe and the exhaust pipe is released from the high-pressure side, i.e., the first medium pipe and the exhaust pipe, to the outside of the exhaust pipe on the low-pressure side. Along with the release of this gas, condensed water present in the first medium pipe and the exhaust pipe can be discharged. Also, along with the release of this gas, steam containing water vapor present in the first medium pipe and the exhaust pipe can be discharged. Therefore, when starting the power generation facility, since water in the form of a liquid does not move to the fluid machine, the power generation facility can be started smoothly.

[0008] The above-described method for operating the power generation facility may further include a stop step of stopping the operation of the fluid machine as a compressor after the discharge step, a closing step of closing the exhaust control valve and the intake control valve after the stop step, and a power generation step of generating electric power with the rotating machine by opening the supply control valve after the closing step. According to these steps, after condensate is discharged in the discharging step, electric power is generated by a rotating machine. Therefore, when starting the fluid machine to generate electric power by the rotating machine, water as a liquid does not move to the fluid machine. Therefore, the power generation facility can be started smoothly.

[0009] The operation method of the power generation facility described above may further include an opening step of opening an intake control valve before the supply step. According to this step, the gas used to discharge condensate can be taken in.

[0010] The operation method of the power generation facility described above may further include a stopping step of stopping the operation of generating electric power by the rotating machine by closing the supply control valve before the supply step, and an opening step of opening the intake control valve after the stopping step and before the supply step. According to this step, in a state where the steam containing water vapor present in the first medium pipe and the exhaust pipe is discharged in the discharging step, a standby state in which electric power is not generated by the rotating machine can be maintained. As a result, since water vapor does not condense in the first medium pipe and the exhaust pipe, water as a liquid does not move to the fluid machine either. Therefore, when starting the power generation facility, the power generation facility can be started smoothly.

[0011] A power generation system according to another aspect of the present invention includes a rotating machine having a coil and a magnet, a fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, a first medium pipe that is connected to a first input / output portion of the fluid machine and is provided with a supply control valve, a second medium pipe that is connected to a second input / output portion of the fluid machine, an exhaust pipe that is connected between the supply control valve and the first input / output portion in the first medium pipe and is provided with an exhaust control valve, an intake pipe that is connected to the second medium pipe and is provided with an intake control valve, and an operation control device that controls the operations of the supply control valve, the exhaust control valve, and the intake control valve. When the supply control valve and the exhaust control valve are closed and the intake control valve is open, the operation control device operates the fluid machine as a compressor, and after performing the operation of supplying the gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than the atmospheric pressure to the first medium pipe and the exhaust pipe, the operation control device performs the operation of discharging the gas from the first medium pipe and the exhaust pipe by opening the exhaust control valve.

[0012] Still another aspect of the present invention is an operation control device used in a power generation facility, which includes a rotating machine having a coil and a magnet, a fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, a first medium pipe that is connected to the first input / output part of the fluid machine and is provided with a supply control valve, a second medium pipe that is connected to the second input / output part of the fluid machine, an exhaust pipe that is connected between the supply control valve and the first input / output part in the first medium pipe and is provided with an exhaust control valve, and an intake pipe that is connected to the second medium pipe and is provided with an intake control valve. When the supply control valve and the exhaust control valve are closed and the intake control valve is open, the operation control device operates the fluid machine as a compressor, and after performing the operation of supplying the gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than the atmospheric pressure to the first medium pipe and the exhaust pipe, the operation control device performs the operation of discharging the gas from the first medium pipe and the exhaust pipe by opening the exhaust control valve.

[0013] The above-described operation control device performs a supply operation and a discharge operation similar to those of the operation method of the power generation facility. Therefore, when starting the power generation facility, since water, which is a liquid, does not move to the fluid machine, the power generation facility can be started smoothly.

Advantages of the Invention

[0014] According to the present invention, there are provided an operation method of a power generation facility, a power generation system, and an operation control device that can smoothly start the power generation facility.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted.

[0017] FIG. 1 is a schematic diagram showing the configuration of a power generation system 1. The scroll expander 2 is connected to a generator 4 by a shaft 3. The scroll expander 2 receives steam G1. The scroll expander 2 converts the expansion of the received steam G1 into the rotational motion of the shaft 3. Then, the generator 4 generates electric power 3P in response to the rotation of the shaft 3.

[0018] Here, the power generation system 1 mutually switches between a standby state in which electric power 3P is not generated and a power generation state in which electric power 3P is generated according to the demand for electric power. That is, the power generation system 1 may perform an operation of switching from the standby state to the power generation state. The operation of switching from the standby state to the power generation state is referred to as a start-up operation.

[0019] As a factor that inhibits the smooth startup operation of the power generation system 1, the liquid in the piping can be cited. As described above, steam G1 is supplied to the scroll expander 2 as a working medium. When the power generation system 1 is in the power generation state, the steam G1 flowing through the piping and the scroll expander 2 contains water as steam. When the power generation system 1 switches from the power generation state to the standby state, the supply of steam G1 to the scroll expander 2 is stopped. Then, the temperature of the steam G1 existing in the piping drops. As a result, the steam contained in the steam G1 changes into condensed water. There may be water, which is a liquid, in the piping when in the standby state.

[0020] And when switching from the standby state to the power generation state, the supply of steam G1 to the scroll expander 2 is resumed. At this time, if there is condensed water in the piping, the condensed water will move into the scroll expander 2 together with the steam G1. When condensed water enters the scroll expander 2, it causes malfunction of the scroll expander 2. That is, the smooth startup of the power generation system 1 is inhibited. Therefore, the power generation system 1 of the embodiment executes an operation method for smoothly performing the startup operation.

[0021] First, a specific example of the power generation system 1 will be described. Next, as a first embodiment, an operation method for smoothly performing the startup operation when switching from the standby state to the power generation state will be described. And when switching from the power generation state to the standby state, as a second embodiment, an operation method for smoothly performing the next startup operation will be described.

[0022] <Power Generation System> The power generation system 1 includes a power generation facility 10 and a controller 80 (operation control device). And the power generation facility 10 includes a scroll expander 2, a generator 4, and a piping system 5.

[0023] The scroll expander 2 has a pair of scrolls. The scrolls have spiral wraps in plan view. The pair of wraps forms closed spaces called a plurality of pockets. As the volume of the pockets gradually expands, for example, one scroll rotates relative to the other scroll. The rotational movement of the other scroll is converted into a rotational movement around a predetermined axis of rotation by an eccentric shaft. Hereinafter, the rotational direction of the shaft 3 caused by the expansion of the vapor G1 is referred to as the forward rotation.

[0024] The change in the volume of the pockets is brought about by the expansion of the vapor G1. The scroll expander 2 has a first input / output port 21 (first input / output part) for receiving the vapor G1 before expansion and a second input / output port 22 (second input / output part) for discharging the vapor G1 after expansion.

[0025] This scroll expander 2 is a machine that converts the expansion of the vapor G1, which is the working medium, into the rotation of the shaft 3. Further, conversely, the scroll expander 2 can also relatively rotate a pair of scrolls by the rotation of the shaft 3 to compress the gas. That is, the scroll expander 2 can also function as a compressor. When operating the scroll expander 2 as a compressor, the other scroll may be rotated in the direction opposite to the rotational direction (forward rotation) caused by the expansion of the vapor G1.

[0026] When operating the scroll expander 2 as a compressor, the gas before compression is received from the second input / output port 22. Then, the compressed gas is discharged from the first input / output port 21.

[0027] That is, the scroll expander 2 provided in the power generation facility 10 is a scroll fluid machine capable of performing two functions. In the following description, for convenience, it is referred to as the "scroll expander 2", but this does not exclude the function of compressing the gas. The specific configuration of the scroll expander 2 provided in the power generation facility 10 is not particularly limited and includes any scroll fluid machine having a pair of scrolls.

[0028] The generator 4 has a rotor and a stator. The rotor can rotate in response to the rotation of the shaft 3 and includes a magnet as a component. The stator is a component arranged to surround the rotor and includes a coil as a component. In response to the rotational motion of the scroll expander 2, the rotor rotates. As a result, an electromotive force is generated in the coil due to the interaction between the rotating magnet and the coil. That is, the generator 4 can generate electric power 3P in response to the rotational motion of the scroll expander 2.

[0029] This generator 4 can also function as an electric motor by receiving a supply of electric power 3S from the outside. That is, the generator 4 provided in the power generation facility 10 is a rotating machine capable of performing two functions. In the following description, for convenience, it is referred to as the "generator 4", but this does not exclude its function as an electric motor. The specific configuration of the generator 4 provided in the power generation facility 10 is not particularly limited and includes any machine having a coil and a magnet.

[0030] The power generation facility 10 further includes a piping system 5. The piping system 5 has a steam supply pipe 51 (first medium pipe), an exhaust branch pipe 52 (exhaust pipe), a steam discharge pipe 53 (second medium pipe), and an intake branch pipe 54 (intake pipe).

[0031] The steam supply pipe 51 guides the steam G1 flowing in the main steam pipe 9 to the scroll expander 2. One end of the steam supply pipe 51 is connected to the main steam pipe 9. The other end of the steam supply pipe 51 is connected to the first input / output port 21 of the scroll expander 2. A pressure sensor 7 for measuring the pressure inside the pipe is attached to the steam supply pipe 51.

[0032] A supply control valve 511 is provided in the steam supply pipe 51. The supply control valve 511 mutually switches between a state in which steam G1 can be supplied from the main steam pipe 9 to the scroll expander 2 and a state in which the supply of the steam G1 from the main steam pipe 9 to the scroll expander 2 is blocked. The state in which the steam G1 can be supplied is referred to as the "open state" or simply "open". The state in which the supply of the steam G1 is blocked is referred to as the "closed state" or simply "closed". The switching between the open state and the closed state of the supply control valve 511 may be in accordance with a supply control signal C51 received from the controller 80. Also, the switching between the open state and the closed state of the supply control valve 511 may be manually performed by an operator. In the following description, the operation of the supply control valve 511 is assumed to be under the control of the controller 80.

[0033] The exhaust branch pipe 52 is for discharging the fluid existing in the steam supply pipe 51. One end of the exhaust branch pipe 52 is connected to the steam supply pipe 51. More specifically, one end of the exhaust branch pipe 52 is connected between the supply control valve 511 and the scroll expander 2 in the steam supply pipe 51. For example, the connection location of the exhaust branch pipe 52 may be in the vicinity of the supply control valve 511. In other words, the distance from the connection location of the exhaust branch pipe 52 to the supply control valve 511 may be shorter than the distance from the connection location of the exhaust branch pipe 52 to the scroll expander 2. The other end of the exhaust branch pipe 52 is open to the atmosphere as an example.

[0034] An exhaust control valve 521 is provided in the exhaust branch pipe 52. The exhaust control valve 521 mutually switches between a state in which the exhaust branch pipe 52 and the steam supply pipe 51 are open ("open state" or "open") and a state in which the exhaust branch pipe 52 and the steam supply pipe 51 are closed ("closed state" or "closed"). Similar to the supply control valve 511, the switching between the open state and the closed state may be in accordance with an exhaust control signal C52 received from the controller 80 or may be manual.

[0035] The steam discharge pipe 53 receives the expanded steam G1 discharged from the scroll expander 2. One end of the steam discharge pipe 53 is connected to the second input / output port 22 of the scroll expander 2. The other end of the steam discharge pipe 53 is connected to an external device (not shown).

[0036] A check valve 531 is provided in the steam discharge pipe 53. For example, taking the flowing direction of the steam G1 discharged from the second input / output port 22 of the scroll expander 2 as the positive direction and the direction in which the gas goes toward the second input / output port 22 of the scroll expander 2 as the reverse direction. When a positive flow occurs in the steam discharge pipe 53, the check valve 531 permits the flow from the upstream side (steam discharge pipe 53) to the downstream side of the check valve 531. When a reverse flow occurs in the steam discharge pipe 53, the check valve 531 prohibits the flow from the downstream side to the upstream side (steam discharge pipe 53). This permission and prohibition of the flow automatically switch according to the direction of the fluid flowing in the steam discharge pipe 53. This switching does not require the control of the controller 80 or the switching operation of the operator.

[0037] The intake branch pipe 54 is for taking in air G2 into the steam discharge pipe 53. One end of the intake branch pipe 54 is connected to the steam discharge pipe 53. More specifically, one end of the intake branch pipe 54 is connected between the check valve 531 and the scroll expander 2 in the steam discharge pipe 53. Different from the exhaust branch pipe 52, there is no particular limitation on the connection location of the intake branch pipe 54. The connection location of the intake branch pipe 54 may be near the check valve 531 or near the scroll expander 2. The other end of the intake branch pipe 54 is open to the atmosphere.

[0038] An intake control valve 541 is provided in the intake branch pipe 54. The intake control valve 541 mutually switches between a state where the intake branch pipe 54 and the steam discharge pipe 53 are open ("open state" or "open") and a state where the intake branch pipe 54 and the steam discharge pipe 53 are closed ("closed state" or "closed"). Similar to the supply control valve 511 and the exhaust control valve 521, the switching between the open state and the closed state may be according to the intake control signal C54 received from the controller 80, or may be manual.

[0039] The controller 80 shown in FIG. 2 controls the supply control valve 511, the exhaust control valve 521, and the intake control valve 541. The controller 80 also performs control to operate the generator 4 as an electric motor. As shown in FIG. 2, the controller 80 is a computer having components such as a processor 81, a memory 82, and a timer 83.

[0040] The controller 80 has a function of outputting a supply control signal C51, an exhaust control signal C52, an intake control signal C54, and a drive control signal C6 at appropriate timings. The controller 80 has, as functional components, a pressure determination unit 811, an elapsed time determination unit 812, and a control signal output unit 813. These functional components are realized by the processor 81 executing an operation program stored in the memory 82. That is, the controller 80 exhibits a predetermined function by the processor 81 and the memory 82 operating in cooperation.

[0041] The pressure determination unit 811 performs a predetermined determination operation using the pressure data C7 output by the pressure sensor 7. For example, the predetermined determination operation may be to determine whether the value of the pressure data C7 exceeds a threshold value stored in the memory 82. Further, the predetermined determination operation may be to determine whether the value of the pressure data C7 is lower than another threshold value stored in the memory 82. The pressure determination unit 811 outputs the determination result to the memory 82 or the control signal output unit 813.

[0042] The elapsed time determination unit 812 performs a predetermined determination operation using the time data output by the timer 83. For example, the predetermined determination operation may be to determine whether the elapsed time exceeds a threshold value stored in the memory 82. The elapsed time determination unit 812 outputs the determination result to the memory 82 or the control signal output unit 813.

[0043] The control signal output unit 813 determines whether to output the exhaust control signal C52, the intake control signal C54, and the drive control signal C6 by using at least one of the result of the pressure determination unit 811 or the result of the elapsed time determination unit 812. Further, the control signal output unit 813 can also output a control signal according to a criterion different from these determination results.

[0044] <First Embodiment> Subsequently, the first embodiment will be described. FIG. 3 is a flowchart showing the main steps of the operation method of the power generation facility according to the first embodiment. FIG. 4 is a timing chart showing the operations of the supply control valve 511, the intake control valve 541, the exhaust control valve 521, the generator 4, and the scroll expander 2 in the operation method of the power generation facility according to the first embodiment. FIGS. 5 to 8 are diagrams schematically showing the states of the power generation facility 10 in each step shown in the flowchart of FIG. 3.

[0045] The operation method of the first embodiment is applied to the power generation facility 10 in the standby state (S10: see FIG. 5(a)). When in the standby state (S10), each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0046] When in the standby state (S10), high-temperature steam G1 is flowing in the main steam pipe 9. On the other hand, when in the standby state (S10), high-temperature steam G1 exists upstream of the supply control valve 511 in the steam supply pipe 51, and saturated steam G1 containing condensed water generated by condensation exists downstream of the supply control valve 511 in the steam supply pipe 51. Also, it may be assumed that saturated steam G1 containing condensed water generated by condensation also exists in the steam discharge pipe 53. From this state, the operation method of the first embodiment is started.

[0047] First, open the intake control valve 541 (see S11: Fig. 5(b)). The controller 80 gives an intake control signal C54 that changes the intake control valve 541 from the closed state to the open state. As a result, the intake control valve 541 switches from the closed state to the open state. As a result of step S11, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0048] Next, rotate the scroll expander 2 in the reverse direction (see S12: Fig. 6(a)). Due to this reverse rotation, the generator 4 is driven as an electric motor. The controller 80 gives a drive control signal C6 that supplies power 3S from the power source 6 to the generator 4. As a result, the generator 4 rotates the shaft 3 in the reverse direction, and the scroll expander 2 functions as a compressor.

[0049] More specifically, air G2 is taken in through the intake branch pipe 54. The air G2 passes through the steam discharge pipe 53 and reaches the second input / output port 22 of the scroll expander 2. At this time, since the direction in which the air G2 flows is the reverse flow direction, the check valve 531 is in the closed state. Then, the air G2 is compressed by the scroll expander 2 and discharged from the first input / output port 21 to the steam supply pipe 51. As a result, the gas occupying the inside of the steam supply pipe 51 and the exhaust branch pipe 52 is composed of saturated steam G1 containing water droplets and compressed air G2.

[0050] As described above, since the supply control valve 511 and the exhaust control valve 521 are closed, the pressure inside the steam supply pipe 51 and the exhaust branch pipe 52 increases due to the compressed air G2. The air G2 taken in from the intake branch pipe 54 is at atmospheric pressure, and the air G2 at atmospheric pressure is further compressed. Therefore, the pressure of the air G2 discharged from the scroll expander 2 to the steam supply pipe 51 is at least higher than atmospheric pressure. Therefore, the pressure inside the steam supply pipe 51 and the exhaust branch pipe 52 also becomes higher than atmospheric pressure.

[0051] Next, open the exhaust control valve 521 (see S13: Fig. 6(b)). The controller 80 gives an exhaust control signal C52 that changes the closed exhaust control valve 521 from the closed state to the open state. As a result, the intake control valve 541 switches from the closed state to the open state. As a result of step S13, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Open · Generator 4: Rotating in reverse (operating as an electric motor) · Scroll expander 2: Rotating in reverse (operating as a compressor)

[0052] Here, the internal pressure of the steam supply pipe 51 may be used as a condition for the controller 80 to output the exhaust control signal C52 that changes the closed state to the open state. A pressure gauge 7 for measuring the internal pressure is provided in the steam supply pipe 51. The controller 80 receives the pressure data C7 provided from the pressure gauge 7. Next, the controller 80 determines whether the numerical value of the pressure data C7 exceeds a predetermined pressure threshold. The controller 80 may output the exhaust control signal C52 when the numerical value of the pressure data C7 exceeds the opening pressure threshold.

[0053] The elapsed time starting from the operation (S12) of driving the generator 4 as an electric motor may be used as a condition for the controller 80 to output the exhaust control signal C52 that changes the closed state to the open state. The controller 80 has a timer 83. The controller 80 measures the elapsed time starting from the time when the drive control signal C6 is given. Then, the controller 80 determines whether the elapsed time exceeds a predetermined time threshold. The controller 80 may output the exhaust control signal C52 when the elapsed time exceeds the opening time threshold.

[0054] Since the internal pressures of the steam supply pipe 51 and the exhaust branch pipe 52 are higher than the atmospheric pressure, when the exhaust control valve 521 opens, the internal gas of the steam supply pipe 51 and the exhaust branch pipe 52, which are on the high-pressure side, is released from the inside to the atmospheric environment, which is on the low-pressure side. Specifically, saturated steam G1 containing condensed water and compressed air G2 are released from the steam supply pipe 51 and the exhaust branch pipe 52 to the atmospheric environment. Due to this release, the condensed water present in the steam supply pipe 51 and the exhaust branch pipe 52 is also released.

[0055] That is, as a result of steps S12 and S13, the internal gas of the steam supply pipe 51 and the exhaust branch pipe 52 is replaced from steam G1 containing condensed water to air G2 not containing condensed water. This air G2 only needs to not contain condensed water, and there is no particular limitation on its humidity.

[0056] Next, the operation of the scroll expander 2 is stopped (S14: see Fig. 7(a)). As a result, the drive of the generator 4 as an electric motor is stopped. The controller 80 outputs a drive control signal C6 for stopping the supply of power 3S from the power source 6 to the generator 4. As a result of step S14, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Open · Generator 4: Stopped · Scroll expander 2: Stopped

[0057] Next, the intake control valve 541 and the exhaust control valve 521 are closed (S15: see Fig. 7(b)). The controller 80 gives an intake control signal C54 for changing the open state to the closed state to the intake control valve 541 in the open state. Further, the controller 80 gives an exhaust control signal C52 for changing the open state to the closed state to the exhaust control valve 521 in the open state. As a result of step S15, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0058] Here, as conditions for the controller 80 to output the exhaust control signal C52 and the intake control signal C54 that change from the open state to the closed state, the internal pressure of the steam supply pipe 51 or the elapsed time may be used. When using the internal pressure as a condition, the controller 80 may output the exhaust control signal C52 and the intake control signal C54 when the numerical value of the pressure data falls below the closing pressure threshold. When using the elapsed time as a condition, the controller 80 may use the time starting from the timing when the generator 4 is driven as a generator (S12), or may use the time starting from the timing when the exhaust control signal C52 that changes from the closed state to the open state is output. In any case, the controller 80 may output the exhaust control signal C52 and the intake control signal C54 when the elapsed time exceeds the closing time threshold.

[0059] Next, rotate the generator 4 forward (S16: see Fig. 8(a)). Specifically, the controller 80 outputs a drive signal C4 that supplies power to the generator 4 to rotate it forward. The generator 4 that has received the drive signal C4 rotates forward at a predetermined rotational speed. In a state where the steam G1 is not supplied and the generator 4 is rotating forward at a predetermined rotational speed, it can be said to be in an unloaded state. In the unloaded state, the generator 4 does not generate power. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Rotating forward (rotating in an unloaded state) · Scroll expander 2: Rotating forward

[0060] Next, open the supply control valve 511 (S17: see Fig. 8(b)). The controller 80 applies a supply control signal C51 that changes the supply control valve 511 from the closed state to the open state. As a result of step S17, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Open · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Rotates in the positive direction (rotates under a load condition) · Scroll expander 2: Rotates in the positive direction (operates as an expander)

[0061] When the supply control valve 511 is opened, the steam G1 is supplied to the scroll expander 2. Before the steam G1 is supplied to the scroll expander 2, the shaft 3 is rotating at a predetermined rated rotational speed by the no-load rotation of the generator 4. When the supply of the steam G1 is started, the scroll expander 2 applies torque to the rotating shaft 3. Due to this torque, the rotational speed of the shaft 3 tries to increase, but the generator 4 operates so as to maintain the rated rotational speed even in the state where torque is applied (load condition). Specifically, the generator 4 exerts a braking force so as to maintain the rated rotational speed. This braking force becomes regenerative energy and is recovered as electric power. That is, the generator 4 generates electricity.

[0062] Through the above steps S11 to S17, the power generation facility 10 enters a power generation state (S18: see Fig. 8(b)).

[0063] <Function and effect> The operation method of the power generation facility 10 includes a supply step (S12) of operating the scroll expander 2 as a compressor in a state where the supply control valve 511 and the exhaust control valve 521 are closed and the intake control valve 541 is open, so as to supply the air G2 taken in from the intake branch pipe 54 and pressurized by the scroll expander 2 to a pressure higher than the atmospheric pressure to the steam supply pipe 51 and the exhaust branch pipe 52, and an exhaust step (S13) of discharging the gas from the steam supply pipe 51 and the exhaust branch pipe 52 by opening the exhaust control valve 521.

[0064] The power generation system 1 includes a generator 4 having a coil and a magnet, a scroll expander 2 having a pair of scrolls that are connected to the generator 4 and are spiral, a steam supply pipe 51 connected to the first input / output port 21 of the scroll expander 2 and provided with a supply control valve 511, a steam discharge pipe 53 connected to the second input / output port 22 of the scroll expander 2, an exhaust branch pipe 52 connected between the supply control valve 511 and the first input / output port 21 in the steam supply pipe 51 and provided with an exhaust control valve 521, an intake branch pipe 54 connected to the steam discharge pipe 53 and provided with an intake control valve 541, and a controller 80 that controls the operations of the supply control valve 511, the exhaust control valve 521, and the intake control valve 541.

[0065] With the supply control valve 511 and the exhaust control valve 521 closed and the intake control valve 541 open, the controller 80 of the power generation facility 1 operates the scroll expander 2 as a compressor, and after executing the operation of supplying the gas taken in from the intake branch pipe 54 and pressurized by the scroll expander 2 to a pressure higher than atmospheric pressure to the steam supply pipe 51 and the exhaust branch pipe 52, the controller 80 opens the exhaust control valve 521 to execute the operation of discharging the gas from the steam supply pipe 51 and the exhaust branch pipe 52.

[0066] In the operation method of the power generation facility 10 and the operation by the controller 80, air G2 having a pressure higher than the atmospheric pressure is supplied to the steam supply pipe 51 and the exhaust branch pipe 52 by implementing the supply process (S12). When the exhaust control valve 521 provided in the exhaust branch pipe 52 is opened in the steam supply pipe 51 and the exhaust branch pipe 52 in a state where the air G2 having a pressure higher than the atmospheric pressure is supplied, the gas inside the steam supply pipe 51 and the exhaust branch pipe 52 is discharged from the high-pressure side, i.e., the steam supply pipe 51 and the exhaust branch pipe 52, toward the outside of the exhaust branch pipe 52 on the low-pressure side. Along with the discharge of this gas, the condensed water present in the steam supply pipe 51 and the exhaust branch pipe 52 can be discharged. Also, along with the discharge of this gas, the steam containing water vapor present in the steam supply pipe 51 and the exhaust branch pipe 52 can be discharged. Therefore, when starting the power generation facility 10, since the liquid water does not move to the scroll expander 2, the power generation facility 10 can be smoothly started.

[0067] The operation method of the power generation facility 10 further includes a stop process of stopping the operation of the scroll expander 2 as a compressor after the discharge process (S13), a closing process of closing the exhaust control valve 521 and the intake control valve 541 after the stop process, and a power generation process of generating electric power 3P by the generator 4 by opening the supply control valve 511 after the closing process. According to these processes, after the condensed water is discharged by the discharge process (S13), the generator 4 generates the electric power 3P. Therefore, when starting the scroll expander 2 to generate the electric power 3P by the generator 4, since the liquid water does not move to the scroll expander 2, the power generation facility 10 can be smoothly started.

[0068] The operation method of the power generation facility 10 further includes an opening process (S11) of opening the intake control valve 541 before the supply process (S12). According to this process, the gas used for discharging the condensed water can be taken in.

[0069] <Second Embodiment> Next, the second embodiment will be described. The power generation facility 10 to which the operation method of the second embodiment is applied is the same as the power generation facility 10 to which the operation method of the first embodiment is applied. FIG. 9 is a flowchart showing the main steps of the operation method of the power generation facility according to the second embodiment. FIG. 10 is a timing chart showing the operations of the supply control valve 511, the intake control valve 541, the exhaust control valve 521, and the generator 4 in the operation method of the power generation facility according to the second embodiment. FIGS. 11 to 14 are diagrams schematically showing the states of the power generation facility 10 in each step shown in the flowchart of FIG. 9.

[0070] The operation method of the second embodiment is applied to the power generation facility 10 in the power generation state (see FIG. 11(a), S20). When in the power generation state (S20), each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Open · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Rotating in the positive direction (operating as a generator) · Scroll expander 2: Rotating in the positive direction (operating as an expander)

[0071] When in the power generation state (S20), the steam G1 before expansion flows through the main steam pipe 9 and the steam supply pipe 51. Also, the steam G1 after expansion flows in the positive flow direction through the steam discharge pipe 53. From this state, the operation method of the second embodiment is started.

[0072] First, the supply control valve 511 is closed (see S21 in FIG. 11(b)). The controller 80 gives a supply control signal C51 that changes the open state to a closed state to the supply control valve 511 in the open state. As a result, the supply control valve 511 switches from the open state to the closed state. As a result of step S21, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Rotating in the positive direction (rotating in a no-load state) · Scroll expander 2: Rotating in the positive direction

[0073] As a result of this step S21, the generator 4 stops generating power but continues to rotate in an unloaded state.

[0074] Next, the generator 4 is stopped (S22: see Fig. 12(a)). Specifically, the controller 80 stops supplying power to the generator 4. As a result, the rotation of the generator 4 also stops. As a result of step S22, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0075] Next, the intake control valve 541 is opened (S23: see Fig. 12(b)). The controller 80 gives an intake control signal C54 that changes the closed state of the intake control valve 541 from the closed state to the open state. As a result, the intake control valve 541 switches from the closed state to the open state. As a result of step S23, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0076] Here, high-pressure steam G1 exists inside the steam discharge pipe 53, the scroll expander 2, and the steam supply pipe 51 immediately before step S23 is executed. That is, the internal pressure of the steam discharge pipe 53, the scroll expander 2, and the steam supply pipe 51 is higher than the atmospheric pressure. When the intake control valve 541 is opened in this state, the steam G1 is released from the high-pressure side, i.e., the steam discharge pipe 53, the scroll expander 2, and the steam supply pipe 51, to the atmospheric environment.

[0077] Next, drive the generator 4 as an electric motor (S24: see Fig. 13(a)). The controller 80 gives a drive control signal C6 for supplying power 3S from the power source 6 to the generator 4. As a result of step S24, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Closed · Generator 4: Rotating in the reverse direction (operating as an electric motor) · Scroll expander 2: Rotating in the reverse direction (operating as a compressor)

[0078] The controller 80 may output the drive control signal C6 before the internal pressures of the steam supply pipe 51, the inside of the scroll expander 2, and the steam discharge pipe 53 drop to atmospheric pressure. Also, the controller 80 may output the drive control signal C6 after the internal pressures of the steam supply pipe 51, the inside of the scroll expander 2, and the steam discharge pipe 53 reach atmospheric pressure.

[0079] Next, open the exhaust control valve 521 (S25: see Fig. 13(b)). Since the operation in this step S25 is the same as the step S13 of the first embodiment, a detailed description thereof will be omitted. As a result of step S25, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Open · Generator 4: Rotating in the reverse direction (operating as an electric motor) · Scroll expander 2: Rotating in the reverse direction (operating as a compressor)

[0080] On the other hand, the operation in step S25 of the second embodiment is different from the operation in step S13 of the first embodiment. In the first embodiment, by implementing step S13, the water droplets existing in the steam supply pipe 51 and the exhaust branch pipe 52 from the exhaust branch pipe 52 were discharged together with the steam G1. In contrast, at the start (power generation state) of the second embodiment, there are no water droplets in the steam supply pipe 51. Therefore, water droplets are not discharged from the steam supply pipe 51 and the exhaust branch pipe 52 by step S25 of the second embodiment. According to step S25 of the second embodiment, the gas existing inside the steam supply pipe 51 and the exhaust branch pipe 52 can be replaced with dry air G2 that can be regarded as not containing water vapor from the wet steam G1 containing a large amount of water vapor. Therefore, even if the internal temperature of the steam supply pipe 51 and the exhaust branch pipe 52 decreases due to the continuation of the standby state, water droplets will not be generated by condensation.

[0081] Next, the drive of the generator 4 as the motor is stopped (S26: see Fig. 14(a)). Since the operation in this step S26 is the same as that in step S14 of the first embodiment, a detailed description will be omitted. As a result of step S26, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Open · Exhaust control valve 521: Open · Generator 4: Stopped · Scroll expander 2: Stopped

[0082] Then, the intake control valve 541 and the exhaust control valve 521 are closed (S27: see Fig. 14(b)). Since the operation in this step S27 is the same as that in step S15 of the first embodiment, a detailed description will be omitted. As a result of step S27, each element constituting the power generation facility 10 is in the following state. · Supply control valve 511: Closed · Intake control valve 541: Closed · Exhaust control valve 521: Closed · Generator 4: Stopped · Scroll expander 2: Stopped

[0083] After going through the above steps S21 to S27, the power generation facility 10 enters the standby state (S28: see Fig. 14(b)).

[0084] <Function and Effect> The operation method of the power generation facility 10 further includes a stop step (S22) of stopping the operation of generating 3P power by the generator 4 by closing the supply control valve 511 before the supply step (S24), and an opening step (S23) of opening the intake control valve 541 after the stop step (S22) and before the supply step (S24). According to this step, it is possible to maintain a state where 3P power is not generated by the generator 4 in a state where the steam containing water vapor existing in the steam supply pipe 51 and the exhaust branch pipe 52 is discharged by the discharge step (S25). As a result, water vapor does not condense in the steam supply pipe 51 and the exhaust branch pipe 52, so condensed water does not move to the scroll expander 2. Therefore, when starting the power generation facility 10, the power generation facility 10 can be smoothly started.

[0085] <Modification Example> As described above, examples of the operation method of the power generation facility, the power generation system, and the operation control device have been explained. The operation method of the power generation facility, the power generation system, and the operation control device may be implemented in various forms without being limited to the above examples.

Explanation of Reference Numerals

[0086] 1... Power generation system, 10... Power generation facility, 2... Scroll expander (fluid machine), 21... First input / output port (first input / output part), 22... Second input / output port (second input / output part), 4... Generator (rotary machine), 5... Pipe system, 51... Steam supply pipe (first medium pipe), 511... Supply control valve, 52... Exhaust branch pipe (exhaust pipe), 521... Exhaust control valve, 53... Steam discharge pipe (second medium pipe), 531... Check valve, 54... Intake branch pipe (intake pipe), 541... Intake control valve, 7... Pressure gauge, 80... Controller (operation control device), 9... Main steam pipe, S12... Supply step, S13... Discharge step.

Claims

1. A rotating machine having a coil and a magnet, A fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, A first medium pipe connected to the first input / output part of the fluid machine and provided with a supply control valve, A second medium pipe connected to the second input / output part of the fluid machine, An exhaust pipe connected between the supply control valve and the first input / output part in the first medium pipe and provided with an exhaust control valve, An intake pipe connected to the second medium pipe and provided with an intake control valve, and a method for operating a power generation facility comprising: A supply step of operating the fluid machine as a compressor with the supply control valve and the exhaust control valve closed and the intake control valve open, thereby supplying the gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than atmospheric pressure to the first medium pipe and the exhaust pipe; An exhaust step of discharging the gas inside the first medium pipe and the exhaust pipe from the exhaust pipe by opening the exhaust control valve. A method for operating a power generation facility having the above steps.

2. A stop step of stopping the operation of the fluid machine as a compressor after the exhaust step; A closing step of closing the exhaust control valve and the intake control valve after the stop step; A power generation step of generating electric power by the rotating machine by opening the supply control valve after the closing step. The method for operating a power generation facility according to Claim 1 further having the above steps.

3. The method for operating a power generation facility according to Claim 2, further having an opening step of opening the intake control valve before the supply step.

4. A stop step of stopping the operation of generating electric power by the rotating machine by closing the supply control valve before the supply step; The method for operating a power generation facility according to Claim 1, further having an opening step of opening the intake control valve after the stop step and before the supply step.

5. A rotating machine having a coil and a magnet, A fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, A first medium pipe connected to the first input / output part of the fluid machine and provided with a supply control valve, A second medium pipe connected to the second input / output part of the fluid machine, An exhaust pipe connected between the supply control valve and the first input / output part in the first medium pipe and provided with an exhaust control valve, An intake pipe connected to the second medium pipe and provided with an intake control valve, An operation control device that controls the operations of the supply control valve, the exhaust control valve, and the intake control valve, The operation control device, In a state where the supply control valve and the exhaust control valve are closed and the intake control valve is open, by operating the fluid machine as a compressor, after performing an operation of supplying the gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than atmospheric pressure to the first medium pipe and the exhaust pipe, A power generation system that performs an operation of discharging the gas from the first medium pipe and the exhaust pipe by opening the exhaust control valve.

6. A rotating machine having a coil and a magnet, A fluid machine having a pair of scrolls that are connected to the rotating machine and are spiral, A first medium pipe connected to a first input / output portion of the fluid machine and provided with a supply control valve, A second medium pipe connected to a second input / output portion of the fluid machine, An exhaust pipe connected between the supply control valve and the first input / output portion in the first medium pipe and provided with an exhaust control valve, An operation control device used in a power generation facility including an intake pipe connected to the second medium pipe and provided with an intake control valve, In a state where the supply control valve and the exhaust control valve are closed and the intake control valve is open, by operating the fluid machine as a compressor, after performing an operation of supplying the gas taken in from the intake pipe and pressurized by the fluid machine to a pressure higher than atmospheric pressure to the first medium pipe and the exhaust pipe, An operation control device that performs an operation of discharging the gas from the first medium pipe and the exhaust pipe by opening the exhaust control valve.

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