JPH0250302B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a closed cycle gas turbine in which a working medium (e.g., nitrogen, air, helium, carbon dioxide, etc.) is confined within one loop to perform a cycle similar to an open gas turbine cycle. This invention relates to an output control device.

When driving a generator with such a closed cycle gas turbine, it is necessary to minimize frequency fluctuations in the power system in response to power load fluctuations and to precisely control the rotational speed of the turbine.

An object of the present invention is to provide an output control device for a closed cycle gas turbine that can maintain high energy efficiency, improve turbine output response to load fluctuations, and perform precise control. .

The present invention includes an injection on-off valve 18 for inventory operation that supplies the working medium from the gas source 16 to the closed cycle gas turbine, and a discharge on-off valve 20 for inventory operation that discharges the working medium to the gas source 16. and connect a bypass valve 22 in parallel with the turbine 1,
Furthermore, a rotation speed detector 2 that detects the rotation speed of the turbine 1
6, a rotation speed setting circuit 15 for setting the rotation speed, a first subtractor 27 for calculating the deviation ΔN between the outputs of the rotation speed detector 26 and the rotation speed setting circuit 15, and responding to the output of the first subtractor 27. and a first controller 29 that performs proportional, integral, and differential operations to derive a signal representing the additional amount of inventory; and a first controller 29 that detects each pressure at the inlet of the closed cycle gas turbine 1 and the inlet of the compressor 2 to generate a closed cycle gas turbine. Means 33, 34, 3 for estimating the inventory amount in
5, a main controller 32 that derives a signal representing the inventory amount, and an arithmetic unit 31 that adds the output of the first controller 29 and the output of the main controller 32 and subtracts the outputs of the estimating means 33, 34, and 35.
In response to the output of the computing unit 31, the injection on-off valve 18
means 37 for controlling the opening and closing of the bypass valve 22 and the discharge on-off valve 20 so that the deviation ΔN becomes zero; an opening setting device 45 for deriving a signal that makes the opening of the bypass valve 22 approximately 50%; Opening degree detector 4 that detects the opening degree of the valve 22
3, a second subtractor 44 that calculates the deviation between the outputs of the opening degree setter 45 and the opening degree detector 43, and a second subtractor 44 that sets the output to zero when the deviation output of the second subtractor 44 is within a predetermined range E. and a dead band circuit 4 that derives a non-zero output corresponding to the deviation output of the second subtracter 44 when it is outside the range E.
6, an integrating circuit 48 that integrates the output of the dead band circuit 46, a second controller 40 that performs proportional and integral operations in response to the output of the first subtracter 27, and outputs of the integrating circuit 48 and the second controller 40. A third controller determines the deviation of the bypass valve 22 and controls the bypass valve 22.
By this, the bypass valve 22 is operated at the same time as the injection on-off valve 18 and the discharge on-off valve 20 at the beginning of the output fluctuation, and then the injection is opened and closed so that the inventory amount corresponds to the output. The valve 18 and the discharge on/off valve 20 remain operated, and the bypass valve 22
This is a closed cycle gas turbine output control device that maintains high energy efficiency and maintains the turbine output at a desired value by setting the opening to a predetermined approximately 50%.

The present invention also includes an injection on-off valve 18 for inventory operation to supply the working medium from the gas source 16 to the closed cycle gas turbine, and a discharge on-off valve 20 for inventory operation to discharge the working medium to the gas source 16. In this closed cycle gas turbine, a low pressure side compressor 51, an intercooler 53 for cooling the working medium from the low pressure side compressor 51, and a high pressure side compressor 55 are connected in this order. A bypass valve 22 is connected in parallel with the turbine 1,
Furthermore, a rotation speed detector 2 that detects the rotation speed of the turbine 1
6, a rotation speed setting circuit 15 for setting the rotation speed, a first subtractor 27 for calculating the deviation ΔN between the outputs of the rotation speed detector 26 and the rotation speed setting circuit 15, and responding to the output of the first subtractor 27. and a first controller 29 that performs proportional, integral, and differential operations to derive a signal representing the amount of addition to the inventory amount; Means 33, 34, 34a, 35 for detecting each pressure at the inlet and estimating the inventory amount in the closed cycle
, a main controller 32 that derives a signal representing the inventory amount, and an arithmetic unit 31 that adds the output of the first controller 29 and the output of the main controller 32 and subtracts the outputs of the estimation means 33, 34, 34a, and 35. In response to the output of the computing unit 31, the injection on-off valve 18
means 37 for controlling the opening and closing of the bypass valve 22 and the discharge on-off valve 20 so that the deviation ΔN becomes zero; an opening setting device 45 for deriving a signal that makes the opening of the bypass valve 22 approximately 50%; Opening degree detector 4 that detects the opening degree of the valve 22
3, a second subtractor 44 that calculates the deviation between the outputs of the opening degree setter 45 and the opening degree detector 43, and a second subtractor 44 that sets the output to zero when the deviation output of the second subtractor 44 is within a predetermined range E. and a dead band circuit 4 that derives a non-zero output corresponding to the deviation output of the second subtracter 44 when it is outside the range E.
6, an integrating circuit 48 that integrates the output of the dead band circuit 46, a second controller 40 that performs proportional and integral operations in response to the output of the first subtracter 27, and outputs of the integrating circuit 48 and the second controller 40. A third controller determines the deviation of the bypass valve 22 and controls the bypass valve 22.
By this, the bypass valve 22 is operated at the same time as the injection on-off valve 18 and the discharge on-off valve 20 at the beginning of the output fluctuation, and then the injection is opened and closed so that the inventory amount corresponds to the output. The valve 18 and the discharge on/off valve 20 remain operated, and the bypass valve 22
This closed-cycle gas turbine output control device is characterized in that it maintains high energy efficiency and maintains turbine output at a desired value by opening the turbine to a predetermined opening degree of approximately 50%.

FIG. 1 is an overall system diagram of an embodiment of the present invention. Working medium from a compressor 2 driven by a turbine 1 is supplied from a line 3 to a flow line 5 on the high pressure side of a regenerator 4 . Working fluid from the regenerator 4 is supplied to the turbine 1 from a pipe 8 via a heater 7 from a pipe 6 . The working medium from turbine 1 is
It is supplied from the pipe line 9 to the low-pressure side flow passage 10 of the regenerator 4 , and guided from the pipe line 11 to the compressor 2 via the precooler 12 and the pipe line 13 . The output of the turbine 1 drives a generator 15 via a reduction gear device 14 . In this way, a closed cycle gas turbine is constructed.

According to the invention, the working medium from the gas storage tank 16 is supplied from the line 17 to the line 13 via the injection shut-off valve 18 . Further, the working medium from the pipe line 3 is discharged from the pipe line 19 to the storage tank 16 via the discharge on-off valve 20. A bypass pipe line 21 is provided in parallel to the turbine 1 . This bypass line 21 connects the line 3 and the line 9. A bypass valve 22 for controlling the flow rate is interposed in the bypass pipe line 21 .

In a closed cycle, generally the turbine 1
The inlet temperature of the compressor 2 and the inlet temperature of the compressor 2 are controlled to be constant. The pressure within the closed cycle therefore increases or decreases in proportion to the inventory amount.

The injection on-off valve 18 and the discharge on-off valve 20 are controlled to manipulate the filling or inventory amount of the working medium enclosed within the closed cycle. For example, from the storage tank 16 to the conduit 17
By injecting the working fluid from the injection on-off valve 18 into the pipe line 13 through the injection valve 18, the pressure or density of the working medium in the closed cycle can be increased, thereby increasing the output power of the turbine 1. . To discharge the working medium from the closed cycle, the discharge on-off valve 20 is opened, thereby reducing the output power of the turbine 1.

In order to keep the rotational speed of the turbine 1 constant in response to increases and decreases in load, it is necessary to be able to rapidly increase and decrease the inventory amount in response to sudden increases and decreases in load. Therefore, the capacity of the injection on-off valve 18 and the discharge on-off valve 20 must be large, or it is necessary to inject the working medium into the pipe line 13 using an auxiliary compressor. Furthermore, depending on the injection or removal position of the working medium, there is a possibility that a reverse response may occur temporarily or that the compressor 2 may cause surging. In summary, inventory operations alone have poor ability to follow changes in load.

In order to solve this problem, the bypass pipe 21
The opening degree of the bypass valve 22 provided in the
bypassing the working medium to the side. This bypass flow rate may be relatively small. This allows the speed of the turbine 1 to be changed quickly.

In order to control the rotational speed of the turbine 1 by changing the flow rate by the bypass valve 22, it is necessary to always bypass the flow rate of the working medium necessary for control by the bypass valve 22. Because bypass valve 2
If the flow rate according to 2 is set to zero during steady state, when the load decreases, the bypass valve 22 can be opened to bypass the working medium and perform quick follow-up, but on the other hand, when the load increases, the bypass amount can be manipulated. Therefore, the ability to follow an increase in load deteriorates. Therefore, the bypass valve 22 is always opened to bypass the working medium. When the opening degree of the bypass valve 22 is unnecessarily large, energy efficiency decreases. Therefore, the opening degree of the bypass valve 22 during steady state can be set within an operation range that can follow changes in load, and is set to a value that minimizes the decrease in energy efficiency. It is convenient to keep the valve capacity of the bypass valve 22 small and set the valve opening degree in the steady state to, for example, around 50%, since the operating range can be widened.

Referring to FIG. 2, the rotation speed setting value signal from the rotation speed setting circuit 25 and the output from the rotation speed detector 26 that detects the rotation speed of the turbine 1 are calculated by the subtracter 2.
7 is given. Therefore, a signal representing the deviation ΔN between the rotational speed set value NO and the actual rotational speed N1 of the turbine 1 is derived on the line 28. The signal from this line 28 is given to a controller 29 to perform proportional, integral and differential operations, and the signal representing the amount of addition to the inventory amount is given to a calculator 31 from a line 30. This computing unit 31 is given a signal from a main controller 32 .
The arithmetic unit 31 is also given an estimated value of the inventory amount in the closed cycle from the arithmetic circuit 33. The arithmetic circuit 33 estimates the inventory amount in the closed cycle based on the outputs from the pressure detector 34 provided in the conduit 13 and the pressure detector 35 provided in the conduit 8. The output from the computing unit 31 is given to a computing conduit 37 via a line 36.

FIG. 3 is a graph showing the characteristics of the arithmetic circuit 37. The signal from line 36 is the on-off valve 18, 2
The inventory amount to be injected/taken out is represented by 0, and when this signal reaches the value A, the injection on/off valve 18 becomes fully open. When the signal from the line 36 reaches the value B (O<B<A), the injection on/off valve 18 closes. Further, when the negative signal from the line 36 reaches the value C (however, C<O), the discharge on-off valve 20 opens and returns to the value D (however, D<O, |D|
It closes when <|C|). By performing the hysteresis operation of both the on-off valves 18 and 20 in this manner, the opening and closing operations of the on-off valves 18 and 20 are prevented from becoming unnecessarily frequent. Arithmetic circuit 3
A signal from 7 via line 38 controls on-off valve 18 and a signal via line 39 controls discharge on-off valve 20.

The deviation signal from the subtractor 27 via line 28 is also provided to the controller 40 for proportional and integral operation so as not to produce an offset with the rotational speed setpoint. This signal is transmitted to the subtraction circuit 41
given to. The opening degree of the bypass valve 22 is controlled by a signal from the subtraction circuit 41 via the line 42 . The opening degree of the bypass valve 22 is detected by a detector 43. A signal representing the opening degree of the bypass valve 22 from the detector 43 is given to a subtractor 44 . The subtracter 44 is given a signal from the opening setting device 45 . The opening degree setter 45 derives a signal representing the opening degree (approximately 50%) of the bypass valve 22 during steady state. The deviation signal from subtractor 44 is provided to dead band circuit 46 via line 45a. The output signal of dead band circuit 46 has a value corresponding to the signal on line 45 and is led out on line 47. The output from line 47 is applied to an integrating circuit 48 for integration, and then applied to a subtracter 41. When the deviation is within range E, line 4
The signal on line 7 becomes zero, and the signal on line 42 works to make the rotational speed deviation ΔN zero according to the proportional and integral operations of the controller 40, and minute fluctuations in the rotational speed are absorbed. When the deviation is outside the range E, the signal on line 47 takes a corresponding non-zero value, the integral circuit 48 works to keep the valve opening constant, and the signal on line 42 changes to the rotational speed. It acts proportionally and differentially to the deviation ΔN. Therefore, by operating the bypass valve alone, ΔN
However, in this case, the inventory amount is manipulated by the integral operation of the controller 29 so that the signal on the line 45 falls within the range E. The control circuit 40 is configured to be able to suspend the integral operation in order to improve controllability.

The operation will be explained with reference to FIG. Assume that the power load suddenly increases by 10% at time zero from a low power load state as shown in FIG. 41.
In this case, the opening degree of the bypass valve 22 is as shown in FIG.
50% at steady state immediately becomes 0%, and the injection on-off valve 18 immediately becomes fully open as shown by the solid line in FIG. 4. By fully opening the injection on-off valve 18, the inventory amount increases over time as shown by line 1. As a result, the rotational speed of the turbine 1 is suppressed to slight fluctuations, as shown by the solid line in FIG.

Based on the output of the controller 40, the time t1
Thereafter, the opening degree of the bypass valve 22 gradually increases from the set state and finally approaches the valve opening degree of 50%. At time t2, the inflow opening/closing valve 18 is in a closed state. If the rotation speed of the turbine 1 is controlled only by the injection on-off valve 18 without the bypass valve 22, the fourth
As shown by reference numeral 11 in FIG. 4, the rotational speed changes significantly. The present invention solves this problem. Note that the discharge on-off valve 20 remains closed.

Referring to FIG. 5, assume that the power load suddenly decreases by 10% at time zero as shown in FIG. 51. In this case, the opening degree of the bypass valve 22 becomes 100% from 50% in the steady state as shown in FIG. 52. At the same time, the discharge on-off valve 20 becomes fully open as shown by the solid line in FIG. 5, and the inventory amount during the closed cycle gradually decreases as shown by reference numeral 12. As a result, the rotational speed of the turbine 1 changes only slightly, as shown by the solid line in FIG. 5. At time t3, the opening degree of the bypass valve 22 is gradually decreased so that it finally approaches 50%. Time t
4, the discharge on-off valve 20 is closed and a steady state is established. If it were assumed that the bypass valve 22 was not provided, the rotational speed of the turbine 1 would be controlled only by the discharge on-off valve 20, which would result in large fluctuations, as indicated by reference numeral 13 in FIG. will occur. The present invention solves this problem. Note that the injection on-off valve 18 remains closed.

FIG. 6 is an overall system diagram of another embodiment of the present invention. The working medium from the low-pressure side compressor 51 is supplied from the pipe 52 to the high-pressure side flow path 58 of the regenerator 57 via the intercooler 53, the pipe 54, the high-pressure side compressor 55, and the pipe 56. passage 59 to heater 6
0 and is supplied to the turbine 1 from a pipe 61.
The working medium from the turbine 1 flows from a pipe 62 through a flow path 63 on the low pressure side of the regenerator 57, and from a pipe 64 through a precooler 65 and a pipe 66 to the low pressure side compressor 5.
I am guided by 1. In such a closed cycle gas turbine, a storage tank 16 in which a working medium is stored, an injection on-off valve 18,
A discharge on/off valve 20, a bypass pipe line 21, a bypass valve 22 are provided, and a rotation speed detector 26,
Pressure detectors 34, 35 are provided. Further, a pressure detector 34a is provided in association with the intercooler 53. The inventory amount can be accurately estimated by the pressure detectors 34, 35, and 34a. In this manner, the rotational speed of the turbine 1 is controlled to a desired value with rapid responsiveness by using a configuration similar to that of the embodiment shown in FIG. The remaining components are similar to the previous embodiments and are given the same reference numerals.

The invention can be implemented for purposes other than power generation.

As described above, according to the present invention, the following effects are achieved.

(a) At the beginning of the output fluctuation, the bypass valve 22 is operated simultaneously with the injection on-off valve 18 and the discharge on-off valve 20, thereby allowing a quick response.

(b) Since the injection on-off valve 18 and the discharge on-off valve 20 are kept operating so that the inventory amount corresponds to the output, and the bypass valve 22 is set to a predetermined opening of about 50%, the rotation of the turbine 1 is It becomes possible to control output such as numbers with high precision.

In particular, as described above, the bypass valve 22 is set to a predetermined opening degree of about 50%, so that highly accurate control of the output is possible even when the load increases or decreases.

(c) In order to control the inventory amount, the injection on-off valve 18 and the discharge on-off valve 20 are used, so by using these on-off valves, compared to a configuration using a flow control valve, It is easy to increase the capacity and reduce costs, and furthermore, in the present invention, the bypass valve 2
By using 2, sufficient controllability can be obtained.

(d) Also, according to the present invention, a dead band circuit 46 is provided, so that when the deviation output of the second subtractor 44 is within a predetermined range E, the output is zero, and when it is outside the range E, A non-zero output corresponding to the deviation output of the second subtractor 44 is derived. Therefore, the deviation output is in the range E
When it is within the range, the signal given from the third subtractor 41 to the bypass valve 22 follows the proportional and integral operation of the second controller 40 and works to make the rotation speed deviation ΔN zero, thereby reducing the minute rotation speed. Number fluctuations are absorbed. Further, when the deviation output is outside the range E, the integrating circuit 4
8, the valve opening of the bypass valve 22 is kept constant, and the signal given to the bypass valve 22 from the third subtractor 41 performs proportional and differential operations with respect to the rotational speed deviation ΔN. Work as you would. Therefore, operating the bypass valve alone will cause a deviation in the rotational speed deviation ΔN, but
At that time, the inventory amount is manipulated by the integral operation of the first controller 29, so that the deviation output of the second subtractor 44 can be made to fall within the range E.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a configuration for controlling the embodiment of FIG. 1, and FIG. 3 is a graph showing characteristics of the control circuit 37. 4 and 5 are graphs for explaining the operation of the embodiment shown in FIGS. 1 to 3;
The figure is an overall system diagram of another embodiment of the present invention. 1...Turbine, 2,51,55...Compressor, 4,
5, 7... Regenerator, 7, 60... Heater, 12, 65
... Precooler, 14 ... Reduction device, 15 ... Generator, 1
6...Storage tank, 18...Inflow on/off valve, 20
...Discharge opening/closing valve, 21...Bypass pipe line, 22...Bypass valve, 53...Intercooler.

Claims (1)

[Claims] 1. An injection on-off valve 18 for inventory operation to supply working medium from the gas source 16 to the closed cycle gas turbine, and a discharge on-off valve for inventory operation to discharge the working medium to the gas source 16. 2
0, a bypass valve 22 is connected in parallel with the turbine 1,
Furthermore, a rotation speed detector 2 that detects the rotation speed of the turbine 1
6, a rotation speed setting circuit 15 for setting the rotation speed, a first subtractor 27 for calculating the deviation ΔN between the outputs of the rotation speed detector 26 and the rotation speed setting circuit 15, and responding to the output of the first subtractor 27. and a first controller 29 that performs proportional, integral, and differential operations to derive a signal representing the additional amount of inventory; and a first controller 29 that detects each pressure at the inlet of the closed cycle gas turbine 1 and the inlet of the compressor 2 to generate a closed cycle gas turbine. Means 33, 34, 3 for estimating the inventory amount in
5, a main controller 32 that derives a signal representing the inventory amount, and an arithmetic unit 31 that adds the output of the first controller 29 and the output of the main controller 32 and subtracts the outputs of the estimating means 33, 34, and 35.
In response to the output of the computing unit 31, the injection on-off valve 18
means 37 for controlling the opening and closing of the bypass valve 22 and the discharge on-off valve 20 so that the deviation ΔN becomes zero; an opening setting device 45 for deriving a signal that makes the opening of the bypass valve 22 approximately 50%; Opening degree detector 4 that detects the opening degree of the valve 22
3, a second subtractor 44 that calculates the deviation between the outputs of the opening degree setter 45 and the opening degree detector 43, and a second subtractor 44 that sets the output to zero when the deviation output of the second subtractor 44 is within a predetermined range E. and a dead band circuit 4 that derives a non-zero output corresponding to the deviation output of the second subtracter 44 when it is outside the range E.
6, an integrating circuit 48 that integrates the output of the dead band circuit 46, a second controller 40 that performs proportional and integral operations in response to the output of the first subtracter 27, and outputs of the integrating circuit 48 and the second controller 40. A third controller determines the deviation of the bypass valve 22 and controls the bypass valve 22.
By this, the bypass valve 22 is operated at the same time as the injection on-off valve 18 and the discharge on-off valve 20 at the beginning of the output fluctuation, and then the injection is opened and closed so that the inventory amount corresponds to the output. The valve 18 and the discharge on/off valve 20 remain operated, and the bypass valve 22
An output control device for a closed cycle gas turbine, characterized in that it maintains high energy efficiency and maintains turbine output at a desired value by setting the opening to a predetermined approximately 50%. 2. Injection on-off valve 18 for inventory operation to supply the working medium from the gas source 16 to the closed cycle gas turbine, and discharge on-off valve 2 for inventory operation to discharge the working medium to the gas source 16.
In this closed cycle gas turbine, a low pressure side compressor 51 and this low pressure side compressor 51 are provided.
An intercooler 53 that cools the working medium from the turbine and a high-pressure side compressor 55 are connected in this order, and a bypass valve 22 is connected in parallel with the turbine 1.
Furthermore, a rotation speed detector 2 that detects the rotation speed of the turbine 1
6, a rotation speed setting circuit 15 for setting the rotation speed, a first subtractor 27 for calculating the deviation ΔN between the outputs of the rotation speed detector 26 and the rotation speed setting circuit 15, and responding to the output of the first subtractor 27. and a first controller 29 that performs proportional, integral, and differential operations to derive a signal representing the amount of addition to the inventory amount; Means 33, 34, 34a, 35 for detecting each pressure at the inlet and estimating the inventory amount in the closed cycle
, a main controller 32 that derives a signal representing the inventory amount, and an arithmetic unit 31 that adds the output of the first controller 29 and the output of the main controller 32 and subtracts the outputs of the estimation means 33, 34, 34a, and 35. In response to the output of the computing unit 31, the injection on-off valve 18
means 37 for controlling the opening and closing of the bypass valve 22 and the discharge on-off valve 20 so that the deviation ΔN becomes zero; an opening setting device 45 for deriving a signal that makes the opening of the bypass valve 22 approximately 50%; Opening degree detector 4 that detects the opening degree of the valve 22
3, a second subtractor 44 that calculates the deviation between the outputs of the opening degree setter 45 and the opening degree detector 43, and a second subtractor 44 that sets the output to zero when the deviation output of the second subtractor 44 is within a predetermined range E. and a dead band circuit 4 that derives a non-zero output corresponding to the deviation output of the second subtracter 44 when it is outside the range E.
6, an integrating circuit 48 that integrates the output of the dead band circuit 46, a second controller 40 that performs proportional and integral operations in response to the output of the first subtracter 27, and outputs of the integrating circuit 48 and the second controller 40. A third controller determines the deviation of the bypass valve 22 and controls the bypass valve 22.
By this, the bypass valve 22 is operated at the same time as the injection on-off valve 18 and the discharge on-off valve 20 at the beginning of the output fluctuation, and then the injection is opened and closed so that the inventory amount corresponds to the output. The valve 18 and the discharge on/off valve 20 remain operated, and the bypass valve 22
An output control device for a closed cycle gas turbine, characterized in that it maintains high energy efficiency and maintains turbine output at a desired value by setting the opening to a predetermined approximately 50%.