JP6236727B2 - Turbine output estimation method for single-shaft combined cycle plant - Google Patents

Description

  The present invention relates to a turbine output estimation method for a single-shaft combined cycle plant.

  The combined cycle plant includes a gas turbine, an exhaust heat recovery boiler that generates steam by the heat of exhaust gas from the gas turbine, a steam turbine that is driven by steam from the exhaust heat recovery boiler, and a drive of the gas turbine and the steam turbine. And a generator for generating electricity.

  This combined cycle plant is a so-called single-shaft combined cycle plant in which a gas turbine rotor of a gas turbine, a steam turbine rotor of a steam turbine, and a generator rotor of a generator are connected to each other on the same axis. is there.

  In this single-shaft combined cycle plant, a plant output combining the gas turbine output and the steam turbine output can be obtained by measuring the output of the generator. However, in a single-shaft combined cycle plant, it is impossible to individually measure the gas turbine output and the steam turbine output. Therefore, in Patent Document 1 below, the steam turbine output is estimated from the environmental conditions of the steam turbine, such as the steam temperature at the inlet of the steam turbine, the inlet steam pressure, the flow rate of steam flowing into the steam turbine, and the like.

Japanese Patent No. 3702266

  In the operation of a combined cycle plant, it is required to obtain a highly accurate output value as an output value of a gas turbine or a steam turbine in order to realize an operation as high as possible.

  Then, an object of this invention is to provide the turbine output estimation method of the single shaft type combined cycle plant which can obtain a highly accurate output value as a turbine output value.

A turbine output estimation method for a single-shaft combined cycle plant as one aspect according to the invention for achieving the above-described object is as follows.
A gas turbine, an exhaust heat recovery boiler that generates steam by heat of exhaust gas from the gas turbine, a steam turbine that is driven by steam from the exhaust heat recovery boiler, and power generation by driving the gas turbine and the steam turbine A single-shaft combined cycle plant in which the gas turbine rotor of the gas turbine, the steam turbine rotor of the steam turbine, and the generator rotor of the generator are connected to each other on the same axis. In the turbine output estimation method, a bypass operation step of supplying fuel to the gas turbine to operate the gas turbine and bypassing the steam supplied to the steam turbine to the steam turbine, and the bypass operation Bypass measurement process to measure the generator output during the process, and the bypass measurement Using the generator output obtained in extent, to execute a bypass on output estimating step of estimating the gas turbine output, the.

  In the turbine output estimation method, the generator output is obtained in a state where the steam supplied to the steam turbine is bypassed with respect to the steam turbine. For this reason, in the turbine output estimation method, of the generator output, the steam turbine output component of the gas turbine output component generated by driving the gas turbine and the steam turbine output component generated by driving the steam turbine. With respect to, since there are fewer elements to calculate using uncertain parameters, the steam turbine output can be estimated with high accuracy. Therefore, in the turbine output estimation method, the amount of gas turbine output generated by driving the gas turbine out of the generator output can be estimated with high accuracy.

  Here, in the turbine output estimation method of the single shaft combined cycle plant, the steam turbine includes one or more steam turbine units, and in the bypass operation step, the exhausted steam among the one or more steam turbine units. The steam supplied to all the steam turbine parts except the low pressure steam turbine part connected to the condenser for returning the water to the water is bypassed, and the outlet temperature of the low pressure steam turbine part is set to a predetermined upper limit value. While supplying the low-pressure steam turbine section with a flow rate not exceeding the wind-loss prevention steam, the remaining steam is bypassed to the low-pressure steam turbine section, and in the bypass output estimation step, the wind-loss prevention steam is The generator obtained by estimating the steam turbine output generated by driving the low-pressure steam turbine section being supplied and obtained in the bypass measurement step By subtracting the steam turbine output component from the force may be estimated the gas turbine output.

  In the turbine output estimation method, although the steam supplied to each steam turbine part is bypassed to each steam turbine part in the bypass operation step, the low pressure steam turbine part is supplied with windage prevention steam. The temperature of the outlet part of the steam turbine part can be suppressed to the upper limit value or less.

  Further, in any one of the above-described single shaft combined cycle plant turbine output estimation method, in the bypass output estimation step, a value obtained by correcting the mechanical loss of the steam turbine as the steam turbine output is used. Also good.

  In the turbine output estimation method, the steam turbine output generated by driving the steam turbine out of the generator output can be estimated with higher accuracy. Therefore, the gas turbine output generated by driving the gas turbine is also calculated. It can be estimated with higher accuracy.

  Moreover, in the turbine output estimation method of the single shaft combined cycle plant as the one aspect, the steam turbine has one or more steam turbine units, and in the bypass operation step, The steam supplied to all the steam turbine parts except the low pressure steam turbine part connected to the condenser for returning the exhausted steam to water is bypassed, and the outlet temperature of the low pressure steam turbine part is determined in advance. While supplying the low-pressure steam turbine section with wind-flow prevention steam at a flow rate not exceeding the upper limit value, the remaining steam is bypassed to the low-pressure steam turbine section, and the generator output is stabilized. All the steam supplied to the steam turbine section may be bypassed.

  In the turbine output estimation method, the generator output is obtained in a state where all the steam supplied to each steam turbine is bypassed to each steam turbine. Therefore, in the turbine output estimation method, of the generator output, the steam turbine output component of the gas turbine output component generated by the driving of the gas turbine and the steam turbine output component generated by the driving of the steam turbine. Since there are fewer elements to be calculated using uncertain parameters, the steam turbine output can be estimated with high accuracy. Therefore, in the turbine output estimation method, the amount of gas turbine output generated by driving the gas turbine out of the generator output can be estimated with higher accuracy.

  Furthermore, in the turbine output estimation method, it is possible to shorten a period during which steam is not supplied to the low-pressure steam turbine unit while obtaining a stable generator output in a state where steam is not supplied to the low-pressure steam turbine unit.

  Further, in any one of the above-described single shaft combined cycle plant turbine output estimation method, in the bypass output estimation step, a mechanical loss of the generator is added to the generator output obtained in the bypass measurement step. The gas turbine output may be estimated using the obtained value.

  In the turbine output estimation method, the amount of gas turbine output generated by driving the gas turbine out of the generator output can be estimated with higher accuracy.

  In any one of the above-described turbine output estimation methods for the single-shaft combined cycle plant, fuel is supplied to the gas turbine to operate the gas turbine, and steam is supplied to the steam turbine so that the steam turbine is A normal operation step of operating, a normal measurement step of measuring a generator output during the normal operation step, the gas turbine output estimated in the bypass output estimation step, and the power generation obtained in the normal measurement step A normal output estimation step of estimating the steam turbine output using the engine output may be executed.

  In the turbine output estimation method, by using the highly accurate gas turbine output estimated in the bypass output estimation process and the generator output obtained in the normal measurement process, the steam turbine output in the normal operation state is also obtained. It can be estimated with high accuracy.

  In the turbine output estimation method for the single-shaft combined cycle plant that executes the normal power estimation process, obtains environmental conditions of the gas turbine at the time of the bypass measurement process and at the time of the normal measurement process, In the normal-time output estimation step, the bypass-time output estimation step is performed using the gas turbine environmental condition during execution of the bypass-time measurement step and the gas turbine environmental condition during execution of the normal-time measurement step. The estimated gas turbine output is converted into a value at the time of execution of the normal time measurement step, and the execution of the normal time measurement step is performed using the gas turbine output at the time of execution of the normal time measurement step obtained by the conversion. The steam turbine output at the time may be estimated.

  In the turbine output estimation method, the steam turbine output in the normal operation state can be estimated with higher accuracy.

  In the turbine output estimation method of any one of the single-shaft combined cycle plants for executing the normal output estimation step, the normal output estimation step includes the generator output obtained in the bypass estimation step in the generator output. The steam turbine output may be estimated using a value obtained by adding the mechanical loss of the above.

  In the turbine output estimation method, the steam turbine output in the normal operation state can be estimated with higher accuracy.

  In the present invention, a highly accurate output value can be obtained as a turbine output value in a single-shaft combined cycle plant.

It is a systematic diagram of the uniaxial combined cycle plant in one embodiment concerning the present invention. It is a flowchart which shows the turbine output estimation method of the single shaft type combined cycle plant in 1st embodiment which concerns on this invention. It is a timing chart in the implementation process of the turbine output estimation method in 1st embodiment which concerns on this invention. It is explanatory drawing which shows the energy balance of the uniaxial type combined cycle plant in the normal time measurement process in 1st embodiment which concerns on this invention. It is explanatory drawing which shows the energy balance of the uniaxial type combined cycle plant in the measurement process at the time of bypass in 1st embodiment which concerns on this invention. It is a graph which shows the relationship between the atmospheric temperature in 1st embodiment which concerns on this invention, and the temperature correction coefficient regarding a gas turbine output. It is a graph which shows the relationship between the atmospheric pressure in 1st embodiment which concerns on this invention, and the pressure correction coefficient regarding a gas turbine output. It is a timing chart in the implementation process of the turbine output estimation method in 2nd embodiment which concerns on this invention.

  Hereinafter, an embodiment of a turbine output estimating method for a single shaft combined cycle plant according to the present invention will be described with reference to the drawings.

“Embodiment of single-shaft combined cycle plant”
First, prior to the description of the turbine output estimation method for a single-shaft combined cycle plant, an embodiment of this plant will be described with reference to FIG.

  The single-shaft combined cycle plant of this embodiment includes a gas turbine 10, an exhaust heat recovery boiler 40 that generates steam by the heat of exhaust gas EG from the gas turbine 10, and steam that is driven by steam from the exhaust heat recovery boiler 40. A turbine 20, a condenser 51 that returns steam exhausted from the steam turbine 20 to water, a feed water pump 53 that sends water in the condenser 51 to the exhaust heat recovery boiler 40, and the gas turbine 10 and the steam turbine 20. And a generator 30 that generates electric power by driving.

  The gas turbine 10 includes a compressor 11 that compresses air A, a combustor 14 that generates fuel gas by burning fuel F in the air compressed by the compressor 11, and a turbine that is driven by high-temperature and high-pressure combustion gas. 15. The compressor 11 includes a compressor rotor 11r that rotates about an axis, and a compressor casing 11c that rotatably covers the compressor rotor 11r. The turbine 15 includes a turbine rotor 15r that rotates about an axis, and a turbine casing 15c that rotatably covers the turbine rotor 15r. The compressor rotor 11r and the turbine rotor 15r are located on the same axis, and are connected to each other to form the gas turbine rotor 19.

  The steam turbine 20 includes a low-pressure steam turbine unit 21, an intermediate-pressure steam turbine unit 22, and a high-pressure steam turbine unit 23. The low-pressure steam turbine unit 21, the intermediate-pressure steam turbine unit 22, and the high-pressure steam turbine unit 23 can rotate the turbine rotors 21r, 22r, and 23r that rotate about the axis, and the turbine rotors 21r, 22r, and 23r, respectively. And covering casings 21c, 22c, and 23c. The turbine rotors 21 r, 22 r, and 23 r of the steam turbine units 21, 22, and 23 are located on the same axis and are connected to each other to form a steam turbine rotor 29.

  The generator 30 includes a generator rotor 31r that rotates about an axis, and a generator casing 31c that rotatably covers the generator rotor 31r. The generator casing 31c includes a stator that is disposed opposite to the outer peripheral side of the generator rotor 31r. A power cable 35 is connected to the generator 30. This power cable 35 is connected to an external power system 38. The power cable 35 is provided with a circuit breaker 36 and a transformer 37. Further, the power cable 35 is provided with an output meter 88 for measuring the amount of power generated by the generator 30, that is, the output of the generator 30.

  The gas turbine rotor 19, the steam turbine rotor 29, and the generator rotor 31 r are located on the same axis and are connected to each other to form a GTCC rotor 39. The GTCC rotor 39 is provided with a rotational speed meter 87 for measuring the rotational speed of the GTCC rotor 39.

  The condenser 51 is connected to the steam outlet of the low-pressure steam turbine unit 21. The condenser 51 and the exhaust heat recovery boiler 40 are connected by a water supply line 52. The water supply line 52 is provided with the above-described water supply pump 53.

  The exhaust heat recovery boiler 40 includes a low-pressure steam generating unit 41 that generates low-pressure steam, an intermediate-pressure steam generating unit 42 that generates medium-pressure steam having a pressure higher than that of the low-pressure steam, and a high-pressure steam having a pressure higher than that of the intermediate-pressure steam. A high-pressure steam generation unit 43 that generates steam, and a reheating unit 44 that heats the steam exhausted from the high-pressure steam turbine unit 23.

  The low-pressure steam generating unit 41 heat-exchanges a part of the water from the water supply line 52 and the exhaust gas EG, and heats the water to generate low-pressure steam. The intermediate pressure steam generating unit 42 includes an intermediate pressure pump (not shown) that increases the pressure of a part of water from the water supply line 52. The intermediate pressure steam generating unit 42 heat-exchanges the water pressurized by the intermediate pressure pump and the exhaust gas EG, and heats the water to generate intermediate pressure steam. The high-pressure steam generator 43 has a high-pressure pump (not shown) that boosts a part of water from the water supply line 52. The high-pressure steam generator 43 heat-exchanges the water pressurized by the high-pressure pump and the exhaust gas EG, and heats the water to generate high-pressure steam.

  The low pressure steam generation part 41 of the exhaust heat recovery boiler 40 and the steam inlet of the low pressure steam turbine part 21 are connected by a low pressure steam line 61. An intermediate pressure steam line 62 is connected to the intermediate pressure steam generator 42 of the exhaust heat recovery boiler 40. The high-pressure steam generation part 43 of the exhaust heat recovery boiler 40 and the steam inlet of the high-pressure steam turbine part 23 are connected by a high-pressure steam line 63. The steam outlet of the high-pressure steam turbine unit 23 and the steam inlet of the reheating unit 44 are connected by a high-pressure steam recovery line 64. The medium pressure steam line 62 is connected to the high pressure steam recovery line 64. Therefore, the high-pressure steam exhausted from the high-pressure steam turbine unit 23 and the medium-pressure steam from the intermediate-pressure steam generation unit 42 merge and flow into the reheating unit 44. The steam outlet of the reheat part 44 and the steam inlet of the intermediate pressure steam turbine part 22 are connected by a reheat steam line 65. The steam outlet of the intermediate pressure steam turbine section 22 and the low pressure steam line 61 are connected by an intermediate pressure steam recovery line 66.

  The low pressure steam line 61 and the steam inlet side of the condenser 51 are connected by a low pressure steam bypass line 67. The low-pressure steam bypass line 67 is connected to the low-pressure steam generator 41 side in the low-pressure steam line 61 rather than the connection position with the intermediate-pressure steam recovery line 66. The reheat steam line 65 and the steam inlet side of the condenser 51 are connected by a reheat steam bypass line 68. The high-pressure steam line 63 and the high-pressure steam recovery line 64 are connected by a high-pressure steam bypass line 69.

  In the low-pressure steam line 61, a low-pressure steam stop valve 71a and a low-pressure steam control valve 71b are provided between a connection position with the low-pressure steam bypass line 67 and a connection position with the intermediate-pressure steam recovery line 66. In the reheat steam line 65, an intermediate pressure steam stop valve 72a and an intermediate pressure steam control valve 72b are provided on the intermediate pressure steam turbine section 22 side of the connection position with the reheat steam bypass line 68. In the high-pressure steam line 63, a high-pressure steam stop valve 73a and a high-pressure steam control valve 73b are provided on the high-pressure steam turbine section 23 side from the connection position with the high-pressure steam bypass line 69. In the high-pressure steam recovery line 64, a check valve that restricts the flow of steam from the reheating unit 44 side to the high-pressure steam turbine unit 23 is located closer to the high-pressure steam turbine unit 23 than the connection position with the high-pressure steam bypass line 69. 74 is provided.

  The low pressure steam bypass line 67 is provided with a low pressure steam bypass valve 77 that adjusts the flow rate of the steam flowing therethrough. The reheat steam bypass line 68 is provided with a reheat steam bypass valve 78 that adjusts the flow rate of the steam flowing therethrough. The high-pressure steam bypass line 69 is provided with a high-pressure steam bypass valve 79 that adjusts the flow rate of the steam flowing therethrough.

  The single-shaft combined cycle plant of the present embodiment further includes an inlet thermometer 81 that measures the temperature of the steam flowing into the low-pressure steam turbine section 21, an inlet pressure gauge 82 that measures the pressure of the steam, and a low-pressure steam turbine section. 21, an outlet thermometer 83 that measures the temperature of the steam exhausted from 21, an outlet pressure gauge 84 that measures the pressure of this steam, and an atmospheric temperature that measures the temperature of the atmosphere that is the air that the compressor 11 of the gas turbine 10 sucks. And a barometer 86 that measures the atmospheric pressure that is the pressure of the air.

  The inlet thermometer 81 and the inlet pressure gauge 82 are provided on the low-pressure steam turbine section 21 side in the low-pressure steam line 61 from the connection position with the intermediate-pressure steam recovery line 66. Since the steam outlet of the low-pressure steam turbine unit 21 is connected to the condenser 51, the temperature measured by the outlet thermometer 83 is also the temperature at the steam inlet of the condenser 51, and the outlet pressure gauge 84 The pressure to be measured is also the pressure at the steam inlet of the condenser 51.

“First Embodiment of Turbine Output Estimation Method”
The first embodiment related to the turbine output estimation method for the single-shaft combined cycle plant described above will be described according to the flowchart shown in FIG. 2 and the timing chart shown in FIG.

  First, the gas turbine 10 is started (S1 in FIG. 2, t1 in FIG. 3). At this time, the GTCC rotor 39 is rotated by an activation device (not shown). When the gas turbine rotor 19 constituting a part of the GTCC rotor 39 rotates, the compressed air from the compressor 11 starts to be supplied to the combustor 14. For example, when the gas turbine rotor 19 reaches a predetermined rotational speed, the fuel F starts to be supplied to the combustor 14. In the combustor 14, the fuel F burns in the compressed air supplied from the compressor 11, and combustion gas is generated. The combustion gas generated in the combustor 14 flows into the turbine 15 and rotates the gas turbine rotor 19.

  The combustion gas exhausted from the gas turbine 10 flows into the exhaust heat recovery boiler 40 as exhaust gas EG. In the exhaust heat recovery boiler 40, heat is exchanged between the exhaust gas EG and water to heat the water and generate steam.

When the gas turbine rotor 19 (GTCC rotor 39) reaches the rated speed (S2 in FIG. 2, t2 in FIG. 3), the circuit breaker 36 is closed and the generator 30 is inserted into the external power system 38 (S3). . As a result, the generator output PW _GEN starts to be measured by the output meter 88 from this point.

The flow rate of the steam generated in the exhaust heat recovery boiler 40 gradually increases, and the temperature of this steam gradually increases. When the steam from the exhaust heat recovery boiler 40 satisfies the steam condition for supplying to the steam turbine 20 (S4), the steam stop valves 71a, 72a, 73a and the steam control valves 71b of the steam turbine units 21, 22, 23 are provided. , 72b, 73b are opened, and steam is started to be supplied to the steam turbine units 21, 22, 23 (S5 in FIG. 2, t3 in FIG. 3). As a result, from this time point, the generator output PW _GEN measured by the output meter 88 includes the steam turbine output PW _ST .

Thereafter, the flow rate of the fuel supplied to the gas turbine 10 gradually increases, and accordingly, the flow rate of the steam generated in the exhaust heat recovery boiler 40 also gradually increases. For this reason, the gas turbine output PW _GT and the steam turbine output PW _ST gradually increase, and the generator output PW _GEN measured by the output meter 88 also gradually increases.

When the generator output PW _GEN gradually increases and the generator output PW _GEN becomes the rated output of the single-shaft combined cycle plant (S6 in FIG. 2: normal operation process, t4 in FIG. 3), this rated output is reached. The generator output PW _GEN1 is acquired from the output meter 88 in the rated operation state (normal operation state). Further, the atmospheric temperature T _air is obtained from the atmospheric thermometer 85 at this time, and the atmospheric pressure P _air is obtained from the atmospheric pressure meter 86, and these are recorded (S7 in FIG. 2: normal measurement step, t5 in FIG. 3).

  Next, the steam supplied to the steam turbine 20 is bypassed (S8 in FIG. 2: bypass operation step, t6 in FIG. 3). At this time, the reheat steam bypass valve 78 is opened while the intermediate pressure steam stop valve 72a and the intermediate pressure steam control valve 72b are closed. Further, the high pressure steam stop valve 73a and the high pressure steam control valve 73b are closed, while the high pressure steam bypass valve 79 is opened. As a result, the reheat steam from the reheat unit 44 flows into the condenser 51 through the reheat steam line 65 and the reheat steam bypass line 68. The high-pressure steam from the high-pressure steam generator 43 flows into the reheating unit 44 via the high-pressure steam line 63, the high-pressure steam bypass line 69, and the high-pressure steam recovery line 64, and together with the steam from the intermediate-pressure steam generator 42, As described above, the refrigerant flows into the condenser 51 through the reheat steam line 65 and the reheat steam bypass line 68. Therefore, the steam does not flow into the intermediate pressure steam turbine unit 22 and the high pressure steam turbine unit 23.

  At this time, the low pressure steam bypass valve 77 is further opened. As a result, the low-pressure steam from the low-pressure steam generator 41 flows into the condenser 51 via the low-pressure steam line 61 and the low-pressure steam bypass line 67. However, the low-pressure steam stop valve 71a remains open, and the low-pressure steam control valve 71b is slightly opened although it is closed compared to the rated operation state. The opening degree of the low-pressure steam control valve 71b is an opening degree at which the flow rate of the wind-loss preventing steam at a flow rate at which the outlet temperature of the low-pressure steam turbine section 21 does not exceed a predetermined upper limit value.

  The temperature of the low-pressure steam flowing into the low-pressure steam turbine section 21 is lower than the temperatures of the high-pressure steam and reheat steam. Moreover, the low-pressure steam exhausted from the low-pressure steam turbine unit 21 is wet steam. For this reason, the design upper limit temperature of the outlet part in the low pressure steam turbine part 21 is lower than the design upper limit temperature of the outlet part of the high pressure steam turbine part 23 or the intermediate pressure steam turbine part 22. On the other hand, if the turbine rotor 21r of the low-pressure steam turbine unit 21 is rotating even though no steam is flowing into the low-pressure steam turbine unit 21, windage damage causes the outlet of the low-pressure steam turbine unit 21 to The temperature rises. For this reason, here, the above-described wind-loss-preventing steam is supplied to the low-pressure steam turbine section 21 to keep the temperature at the outlet of the low-pressure steam turbine section 21 below the upper limit temperature of the outlet.

When the generator output PW _GEN is stabilized in the bypass operation state in which the steam supplied to the steam turbine 20 is bypassed (t7), the generator output PW _GEN2 is acquired from the output meter 88 as in the normal measurement step (S7). To do. Further, the atmospheric temperature T _air at this time is acquired from the atmospheric temperature meter 85, and the atmospheric pressure P _air is acquired from the atmospheric pressure meter 86, and these are recorded (S 9 in FIG. 2: measurement process at bypass, t 8 in FIG. 3). Furthermore, from the inlet temperature gauge 81 and inlet pressure gauge 82 obtains the inlet temperature T _in and inlet pressure P _in the low pressure steam flowing into the low pressure steam turbine section 21, the outlet temperature gauge 83 and the outlet pressure gauge 84, a low pressure The outlet temperature T _out and outlet pressure P _out of the low-pressure steam exhausted from the steam turbine unit 21 are acquired and recorded.

  When the bypass measurement step (S9) is completed, the steam bypass valves 77, 78, 79 are closed as necessary, and the steam stop valves 71a, 72a, 73a and the steam control valves 71b, 72b, 73b are fully opened. Return to the rated operating condition described above.

When the measurement process at bypass (S9) ends, the gas turbine output PW _GT2 at the time (t8) when the measurement data is obtained by the method described later using the data acquired at the bypass measurement process (S9). And the steam turbine output PW _ST2 is estimated (S10: output estimation step at bypass).

Next, the gas at the time (t5) when the measurement data is obtained using the gas turbine output PW _GT2 obtained in the bypass output estimation step (S10) and the data obtained in the normal measurement step (S7). The turbine output PW _GT1 and the steam turbine output PW _ST1 are estimated (S11: normal time output estimation step).

  A method for estimating the gas turbine output and the steam turbine output in the bypass output estimation step (S10) and the normal output estimation step (S11) will be described.

Fuel is supplied to the gas turbine 10, in the normal operating condition the steam to each steam turbine 21, 22, 23 of the steam turbine 20 is supplied, the gas turbine output _{PW GT1,} steam turbine output _{PW ST1,} the generator The output PW _GEN1 can be _expressed as the following (Expression 1), (Expression 2), and (Expression 3).

PW _GT1 = Q _F1 + Q _AIR1 -Q _GTE1 -LS _GT (Formula 1)
PW _ST1 = Q _HP1 + Q _RH1 + Q _LP1 + Q _RHE1 -Q _HPE1 -Q _RHE1 -Q _LPE1 -LS _ST (Formula 2)
PW _GEN1 = PW _GT1 + PW _ST1 -LS _GEN (Formula 3)

That is, the gas turbine output PW _GT1 in the normal operation state is expressed as follows: (Formula 1) and FIG. 4, the calorific value Q _{F1 of the} fuel F supplied to the gas turbine 10 and the calorie Q of the air A sucked by the gas turbine 10 from the sum of the _AIR1, it becomes heat _{Q GTE1} and a value obtained by subtracting the amount of heat _{LS GT} machine loss of the gas turbine 10 of the exhaust gas EG, which is exhausted from the gas turbine 10.

Further, the steam turbine output PW _ST1 in the normal operation state flows into the high pressure steam heat quantity Q _HP1 flowing into the high pressure steam turbine section 23 and the intermediate pressure steam turbine section 22 as shown in (Equation 2) and FIG. From the sum of the heat quantity Q _{RH1 of the} reheat steam, the heat quantity Q _{LP1 of the} low pressure steam flowing into the low pressure steam turbine section 21 and the heat quantity Q _{RHE1 of the} reheat steam exhausted from the intermediate pressure steam turbine section 22, high pressure steam is obtained. pressure steam quantity Q _HPE1 exhausted from the turbine unit 23, heat quantity Q _RHE1 the reheat steam exhausted from the intermediate pressure steam turbine 22, heat Q of the low-pressure steam exhausted from the low pressure steam turbine section 21 _LPE1, and steam This is a value obtained by subtracting the heat quantity LS _{ST corresponding} to the mechanical loss of the turbine 20.

The generator output PW _GEN1 in the normal operation state is calculated from the sum of the gas turbine output PW _GT1 and the steam turbine output PW _ST1 , as shown in the equation (3) and FIG. _The value is obtained by subtracting _GEN .

Meanwhile, it is necessary to obtain the heat quantity _{Q GTE1} cases, air heat _{Q AIR1} and exhaust gas EG of estimating the gas turbine output _{PW GT1} from (Equation 1). When determining the heat quantity Q _AIR1 of the air, the mass flow rate of the air sucked by the gas turbine 10 is necessary, and when _calculating the heat quantity Q _GTE1 of the exhaust gas EG, the mass of the exhaust gas EG exhausted from the gas turbine 10 is required. A flow rate is required. However, it is difficult to directly measure these mass flow rates, and these masses must be estimated based on various parameters. For this reason, even if the gas turbine output PW _GT1 is simply estimated using (Equation 1), it is difficult to obtain a highly accurate gas turbine output.

Further, when estimating the steam turbine output PW _ST1 from (Equation 2), it is necessary to obtain the heat quantity Q _{LPE1 of the} low-pressure steam exhausted from the low-pressure steam turbine section 21. When _obtaining the heat quantity Q _LPE1 of the exhaust low-pressure steam, the pressure and wetness of the low-pressure steam are required to obtain the enthalpy of the exhaust low-pressure steam. However, it is difficult to directly measure the wetness of the exhaust low-pressure steam, and this wetness must be estimated based on various parameters. For this reason, even if the steam turbine output PW _ST1 is estimated using (Equation 2), it is difficult to obtain a highly accurate steam turbine output.

Therefore, in the present embodiment, the generator output PW _GEN2 in the bypass operation state is acquired in the bypass measurement step (S9), and the steam turbine output in the bypass output estimation step (S10) based on the generator output PW _GEN2. PW _ST2 and gas turbine output PW _GT2 are estimated.

In the bypass operation state, the gas turbine output PW _GT2 , the steam turbine output PW _ST2 , and the generator output PW _GEN2 can be expressed as the following (Expression 4), (Expression 5), and (Expression 6).

PW _GT2 = Q _F2 + Q _AIR2 −Q _GTE2 −LS _GT (Formula 4)
PW _ST2 = Q _LP2 -Q _LPE2 -LS _ST (Formula 5)
PW _GEN2 = PW _GT2 + PW _ST2 -LS _GEN (Expression 6)

That is, the gas turbine output PW _GT2 in the bypass operation state is equal to the calorific value Q _{F2 of the} fuel F supplied to the gas turbine 10 as in the above-described normal operation state, as shown in (Equation 4) and FIG. from the sum of the amount of heat _{Q AIR2} of air a gas turbine 10 is sucked, the heat quantity _{Q GTE2} and a value obtained by subtracting the amount of heat _{LS GT} machine loss of the gas turbine 10 of the exhaust gas EG, which is exhausted from the gas turbine 10.

Further, the steam turbine output PW _ST2 in the bypass operation state is exhausted from the low-pressure steam turbine unit 21 from the heat quantity Q _LP2 of the low-pressure steam flowing into the low-pressure steam turbine unit 21 as shown in (Equation 5) and FIG. This is a value obtained by subtracting the heat quantity Q _{LPE2 of the} low-pressure steam and the heat quantity LS _{ST corresponding} to the mechanical loss of the steam turbine 20. As described above, in the present embodiment, a value obtained by correcting the heat quantity LS _{ST corresponding} to the mechanical loss of the steam turbine 20 is used as the steam turbine output PW _ST2 in the bypass operation state.

As in the above-described normal operation state, the generator output PW _GEN2 in the bypass operation state is obtained from the addition value of the gas turbine output PW _GT2 and the steam turbine output PW _ST2 , as shown in Expression (6) and FIG. A value obtained by subtracting the heat quantity LS _{GEN corresponding} to the mechanical loss of the generator 30 is obtained.

By the way, it is difficult to estimate the gas turbine output PW _GT2 in the bypass operation state with high accuracy using (Equation 4), as in the normal operation state.

However, it is possible to estimate the steam turbine output PW _ST2 in the bypass operation state with high accuracy using (Equation 5). When estimating the steam turbine output PW _ST2 in the bypass operation state using (Equation 5), the amount of heat Q _LP2 of the low-pressure steam flowing into the low-pressure steam turbine unit 21 and the low-pressure steam exhausted from the low-pressure steam turbine unit 21 It is necessary to obtain the heat quantity Q _LPE2 and the heat quantity LS _{ST corresponding} to the mechanical loss of the steam turbine 20.

The heat quantity LS _ST corresponding to the mechanical loss of the steam turbine 20 appears mainly as the heat generation amount of the bearing portion. The heat generation amount Q _STB of the bearing portion can be expressed by the following (formula 7).
Q _STB = μ · P · V (Formula 7)

Here, μ is a friction coefficient of the bearing portion, P is a surface pressure of the bearing portion, and V is a sliding speed of the bearing portion. These values are all determined at the design stage. For this reason, the heat quantity LS _{ST corresponding} to the mechanical loss of the steam turbine 20 can be obtained in advance using these values. Further, by checking the flow rate of the lubricating oil supplied to the bearing portion, the inlet temperature and the outlet temperature of the lubricating oil, and using them, the heat quantity LS _{ST corresponding} to the mechanical loss of the steam turbine 20 can be obtained. .

The amount of heat Q _{LP2 of} low-pressure steam (hereinafter referred to as inflow steam) flowing into the low-pressure steam turbine section 21 and the amount of heat Q _LPE2 of low-pressure steam (hereinafter referred to as exhaust steam) discharged from the low-pressure steam turbine section 21 Is the product of the mass flow rate of the low pressure steam and the enthalpy of the low pressure steam.

  The mass flow rate of the incoming steam and the mass flow rate of the exhaust steam are substantially the same and can be obtained in a known manner. For example, there is a method of acquiring the volume flow rate of the incoming steam and converting the volume flow rate into a mass flow rate using the pressure and temperature of the incoming steam. There is also a method of acquiring the mass flow rate of the directly entering steam using a mass flow meter. In addition, as a method of acquiring the volume flow rate, in addition to a method of directly acquiring using a volume flow meter, as described in Japanese Patent No. 3702266, the opening of the steam control valve and the steam control valve There is a method of obtaining by calculation using various coefficients determined by characteristics.

Inlet steam are the dry steam, the enthalpy of the inlet steam may be determined by the pressure P _in the temperature T _in the inlet vapor. In this embodiment, in the bypass measurement step (S9), the pressure P _in of the inflowing steam is acquired from the inlet pressure gauge 82, and the temperature T _{in of the} inflowing steam is acquired from the inlet thermometer 81. Thus, by using the pressure P _in and the temperature T _in the inlet vapor obtained in the bypass when the measurement step (S9), it is possible to determine the enthalpy of the incoming steam.

In the bypass operation state, the wind-loss-preventing steam is supplied to the low-pressure steam turbine unit 21, but the flow rate of the wind-loss-preventing steam is equal to the flow rate of the low-pressure steam flowing into the low-pressure steam turbine unit 21 in the normal operation state. Much less. For this reason, the steam that has flowed into the low-pressure steam turbine section 21 in the bypass operation state is exhausted as dry steam or steam close thereto, unlike the case of being exhausted from the low-pressure steam turbine section 21 in the normal operation state. Therefore, the enthalpy of the exhaust steam can be obtained from the pressure P _out and the temperature T _out of the exhaust steam. In the present embodiment, in the bypass measurement step (S 9), the exhaust steam pressure P _out is acquired from the outlet pressure gauge 84, and the exhaust steam temperature T _out is acquired by the outlet thermometer 83. Therefore, the enthalpy of the exhaust steam can be obtained using the pressure P _out and the temperature T _out of the inflow steam acquired in the measurement step (S9) during bypass.

In the present embodiment, the mass flow rates of the inflow steam and the exhaust steam are acquired as described above, and the enthalpies of the inflow steam and the exhaust steam are obtained, and the heat quantity Q _{LP2 of the} inflow steam and the heat quantity Q _{LPE2 of the} exhaust steam are obtained from these. Ask for.

In the present embodiment, as described above using (Equation 5), the calorific value Q _LPE2 (G, P _out , T _out ) of the exhaust steam is _derived from the calorific value Q _LP2 (G, P _in , T _in ) of the inflowing steam. ) And the heat quantity LS _ST (≈Q _STB ) corresponding to the mechanical loss of the steam turbine 20, the steam turbine output PW _ST2 in the bypass operation state is estimated with high accuracy. Note that G is the mass flow rate [kg / h] of steam.

If the steam turbine output PW _ST2 in the bypass operation state can be estimated with high accuracy, the gas turbine output PW _GT2 in the bypass operation state can be estimated with high accuracy using (Equation 6).

Here, when (Formula 6) is arranged by the gas turbine output PW _GT2 , it can be expressed as the following (Formula 8).
PW _GT2 = PW _GEN2 -PW _ST2 + LS _GEN (Expression 8)

In the bypass output estimation step (S10) of the present embodiment, as shown in (Equation 8), the steam turbine output PW estimated earlier from the generator output PW _GEN2 acquired in the bypass measurement step (S9). _ST2 is subtracted, and the heat quantity LS _{GEN corresponding} to the mechanical loss of the generator 30 is added to this to estimate the gas turbine output PW _GT2 in the bypass operation state with high accuracy. The heat quantity LS _{GEN for} the mechanical loss of the generator 30 is obtained in advance by the same method as the heat quantity LS _{ST for} the mechanical loss of the steam turbine 20 described above.

If the fuel flow rate supplied to the gas turbine 10 is the same in the normal operation state and the bypass operation state, the steam turbine output in the normal operation state according to (Equation 3) using the gas turbine output PW _GT2 in the bypass operation state. PW _ST1 can be estimated.

Here, when (Equation 3) is arranged by the steam turbine output PW _ST1 , it can be expressed as the following (Equation 9).
PW _ST1 = PW _{GEN1 -PW GT1} + LS _GEN (Equation 9)

Further, the gas turbine output PW _GT1 in the normal operation state is substantially the same as the gas turbine output PW _GT2 in the bypass operation state. Therefore, in the normal time output estimation step (S11), as shown in (Equation 9), the gas turbine output PW in the bypass operation state estimated earlier from the generator output PW _GEN1 acquired in the normal time measurement step (S7). _GT2 is subtracted, and the heat quantity LS _{GEN corresponding} to the mechanical loss of the generator 30 is added thereto to estimate the steam turbine output PW _ST1 in the normal operation state.

If the fuel flow rate supplied to the gas turbine 10 is the same between the normal operation state and the bypass operation state, as described above, the gas turbine output PW _GT1 in the normal operation state and the gas turbine output PW _GT2 in the bypass operation state are almost the same. The same. However, the gas turbine output PW _GT slightly changes according to the environmental conditions at that time. Therefore, in the normal output estimation process (S11) of the present embodiment, the environmental conditions of the gas turbine 10 at the timing (t8) when the generator output PW _GEN2 is acquired in the bypass measurement process (S9), and the normal measurement process ( Using the environmental conditions of the gas turbine 10 at the timing (t5) at which the generator output PW _GEN1 is acquired in S7), the gas turbine output PW _GT2 in the bypass operation state is converted into the gas turbine output PW _GT1 in the normal operation state. From (Equation 9), the steam turbine output PW _ST1 in the normal operation state is estimated.

Examples of the environmental conditions of the gas turbine 10 that affect the gas turbine output PW _GT include the temperature, pressure, and humidity of the air that the gas turbine 10 sucks. The gas turbine output PW _GT tends to decrease as the temperature of the intake air increases. Further, the gas turbine output PW _GT tends to increase as the pressure of the sucked air increases.

Therefore, in the present embodiment, based on such gas turbine output characteristics, as shown in FIG. 6, the temperature correction coefficient characteristic indicating the relationship between the temperature (air temperature) T _air of the sucked _air and the temperature correction coefficient K _T is obtained. Prepare in advance. Further, as shown in FIG. 7, a pressure correction coefficient characteristic indicating the relationship between the pressure (atmospheric pressure) P _{air of the air} to be sucked and the pressure correction coefficient K _P is prepared in advance. Similarly, correction coefficient characteristics indicating the relationship between parameters such as humidity of the air to be sucked and correction coefficients K _X , K _Y ,... Are prepared in advance.

Then, the atmospheric temperature T ₂ at the timing (t8) at which the generator output PW _GEN2 is acquired in the bypass measurement step (S9), and the atmosphere at the timing (t5) at which the generator output PW _GEN1 is acquired in the normal measurement step (S7). get the temperature T _1, by using the temperature correction coefficient characteristics, determine the temperature correction coefficient K _T2, K _T1 corresponding to the respective ambient temperature. Further, the atmospheric pressure P ₂ at the timing (t8) at which the generator output PW _GEN2 is acquired in the bypass measurement step (S9), and the timing at the timing (t5) at which the generator output PW _GEN1 is acquired in the normal measurement step (S7). get the pressure P _1, using the pressure correction coefficient characteristics, determine the pressure correction coefficient K _P2, K _P1 in accordance with the respective atmospheric pressure. Similarly, parameter values such as humidity at the timing (t8) when the generator output PW _GEN2 is acquired in the bypass measurement step (S9), and the timing (t5) when the generator output PW _GEN1 is acquired in the normal measurement step (S7). Parameter values such as humidity are obtained, and correction coefficients corresponding to the respective parameter values are obtained using the correction coefficient characteristics.

Next, the atmospheric temperature correction coefficient K _T2 at the timing (t8) at which the generator output PW _GEN2 is acquired in the bypass measurement step (S9), and the timing at which the generator output PW _GEN1 is acquired at the normal measurement step (S7) ( A ratio (K _T1 / K _T2 ) with the atmospheric temperature correction coefficient K _{T1 at} t5) is obtained. Similarly, for the other parameters, the correction coefficient _{K 2} at a timing obtained generator output _{PW GEN2} (t8) in the bypass when the measurement step (S9), the generator output _{PW GEN1} in normal measuring step (S7) A ratio (K ₁ / K ₂ ) with the correction coefficient K ₁ at the acquired timing (t5) is obtained.

As described above, when the ratio of the correction coefficient (K ₁ / K ₂ ) relating to each parameter is obtained, the correction coefficient relating to each parameter is obtained in the gas turbine output PW _GT2 in the bypass operation state as shown in the following (Equation 10). The gas turbine output PW _GT2 in the bypass operation state is converted into the gas turbine output PW _GT1 in the normal operation state by multiplying the ratio (K ₁ / K ₂ ).
_{PW GT1 = PW GT2 × (K} T1 / K T2) × (K P1 / K P2) × (K X1 / K X2) × (K Y1 / K Y2) × ... ··· ( Equation 10)

When the gas turbine output PW _GT2 in the bypass operation state is converted into the gas turbine output PW _GT1 in the normal operation state, as described above, the gas turbine output PW _GT1 in the normal operation state obtained by the conversion is used (Formula 9). Accordingly, the steam turbine output PW _ST1 in the normal operation state is estimated.

  As described above, in this embodiment, a highly accurate output can be obtained as the gas turbine output and the steam turbine output of the single-shaft combined cycle plant.

“Second Embodiment of Turbine Output Estimation Method”
A second embodiment of the turbine output estimation method for the single-shaft combined cycle plant will be described with reference to the timing chart shown in FIG.

  In the bypass operation step (S8) of the first embodiment, wind-loss preventing steam is supplied to the low-pressure steam turbine unit 21. On the other hand, in the bypass operation process of the present embodiment, no steam is supplied to the low-pressure steam turbine unit 21. That is, in the bypass operation process of this embodiment, all the steam supplied to all the steam turbine units 21, 22 and 23 is bypassed.

  In the present embodiment, as in the first embodiment, after the normal measurement process in the normal operation state, the bypass operation process is executed, and the bypass measurement process in the bypass operation state is executed.

  At the time of transition from the normal operation state to the bypass operation state, the reheat steam bypass valve 78 is opened while the intermediate pressure steam stop valve 72a and the intermediate pressure steam control valve 72b are closed as in the first embodiment. Further, the high pressure steam stop valve 73a and the high pressure steam control valve 73b are closed, while the high pressure steam bypass valve 79 is opened. Furthermore, while the low pressure steam bypass valve 77 is opened, the low pressure steam control valve 71b is narrowed down to an opening degree at which the windage prevention steam can be supplied to the low pressure steam turbine section 21 (t6). That is, the operations up to the above are the same as the operations at the time of transition from the normal operation state to the bypass operation state in the first embodiment.

In this embodiment, after the generator operation PW _GEN is stabilized after performing the above operation (t7), the low pressure steam stop valve 71a and the low pressure steam control valve 71b are closed (t8a: bypass operation step). As a result, all the steam supplied to all the steam turbine units 21, 22, and 23 is bypassed. In this embodiment, this state is a bypass operation state.

After the single-shaft combined cycle plant enters the bypass operation state and the generator output PW _GEN is stabilized (t9), the generator output PW _GEN3 is obtained from the output meter 88 and recorded (t10: measurement process at bypass). .

  Immediately after the bypass measurement process is completed, the steam bypass valves 77, 78, and 79 are closed, the steam stop valves 71a, 72a, and 73a and the steam control valves 71b, 72b, and 73b are fully opened, and the above-described rated operation is performed. Return to the state.

Also in the present embodiment, the gas turbine output PW _GT3 at the time when the measurement data is obtained is estimated using the data acquired in the bypass measurement process (bypass output estimation process).

In the bypass operation state of the present embodiment, the gas turbine output PW _GT3 , the steam turbine output PW _ST3 , and the generator output PW _GEN3 are _expressed as the following (Expression 11), (Expression 12), and (Expression 13). Can do.

_{PW GT3 = Q F3 + Q AIR3} -Q GTE3 -LS GT ··· ( Equation 11)
PW _ST3 = −LS _ST (Formula 12)
PW _GEN3 = PW _GT3 + PW _ST3 -LS _GEN
= PW _GT3 -LS _ST -LS _GEN (Formula 13)

That is, the gas turbine output PW _GT3 in the bypass operation state of the present embodiment is the amount of heat generated by the fuel supplied to the gas turbine 10 as in the bypass operation state of the first embodiment, as shown in (Equation 11). from the sum of the amount of heat _{Q AIR3} of air Q _F3 and a gas turbine 10 is sucked, the heat quantity _{Q GTE3} and a value obtained by subtracting the amount of heat _{LS GT} machine loss of the gas turbine 10 of the exhaust gas EG, which is exhausted from the gas turbine 10 Become.

Further, the steam turbine output PW _ST3 in the bypass operation state is the amount of heat that contributes to driving the generator 30 as shown in (Equation 12) because steam is not supplied to any of the steam turbine units 21, 22, and 23. There is no minute, and only the amount of heat (-LS _ST ) corresponding to the mechanical loss of the steam turbine 20 is obtained.

As in the case of the bypass operation state of the first embodiment, the generator output PW _GEN3 in the bypass operation state is obtained by adding the gas turbine output PW _GT3 and the steam turbine output PW _ST3 as shown in (Equation 13): A value obtained by subtracting the heat quantity LS _{GEN corresponding} to the mechanical loss of the generator 30 is obtained. However, in the present embodiment, as described above, since the steam turbine output PW _ST3 in the bypass operation state is only the heat amount (−LS _ST ) corresponding to the mechanical loss of the steam turbine 20, the generator output PW _GEN3 in the bypass operation state. Is a value obtained by subtracting the heat quantity LS _{ST for} the mechanical loss of the steam turbine 20 and the heat quantity LS _GEN for the mechanical loss of the generator 30 from the gas turbine output PW _GT3 .

Here, when (Equation 13) is arranged by the gas turbine output PW _GT3 , it can be expressed as the following (Equation 14).
PW _GT3 = PW _GEN3 + LS _ST + LS _GEN (Formula 14)

Therefore, in the bypass output estimation step of the present embodiment, the heat output LS _{ST for} the mechanical loss of the steam turbine 20 and the mechanical loss of the generator 30 that are obtained in advance in the generator output PW _GEN3 acquired in the bypass measurement step. _Is added to estimate the gas turbine output PW _GT3 .

Then, like the first embodiment, the environmental conditions of the gas turbine 10 at the timing obtained generator output PW _GEN3 bypass time measuring step (t10), and obtains the generator output PW _GEN1 in normal measuring process Using the environmental conditions of the gas turbine 10 at the timing (t5), the gas turbine output PW _GT3 in the bypass operation state is converted into the gas turbine output PW _GT1 in the normal operation state, and then the gas turbine output PW obtained by conversion is converted. _{Using GT1} , steam turbine output PW _ST1 in a normal operation state is estimated.

As described above, in the present embodiment, in estimating the gas turbine output PW _GT3 in the bypass output estimating step, the number of elements to be estimated by calculation is smaller than that in the first embodiment, and therefore, the gas turbine output PW than in the first embodiment. The accuracy of _GT3 can be increased. As a result, it is possible to improve the accuracy of the gas turbine output PW _GT1 and the steam turbine output PW _ST1 estimated in the normal output estimation process.

However, in this embodiment, when acquiring the generator output PW _GEN3 in the measurement process at the time of bypass, the steam is not supplied to the low-pressure steam turbine unit 21. For this reason, at the time of performing the measurement process at the time of bypass, there is a possibility that the temperature of the outlet part of the low-pressure steam turbine part 21 may exceed the upper limit temperature due to windage. Therefore, it is preferable to make the state where steam is not supplied to the low-pressure steam turbine unit 21 as short as possible. On the other hand, when the generator output PW _GEN3 is acquired in the measurement process at the time of bypass, the generator output PW _GEN needs to be stable, and the low-pressure steam bypass is required during the transition from the normal operation state to the bypass operation state. A certain amount of time is required until the generator output PW _GEN is stabilized after the valve 77 is opened and the low-pressure steam control valve 71b is started to close.

Therefore, in this embodiment, in order to shorten the period during which steam is not supplied to the low-pressure steam turbine unit 21 as much as possible, while obtaining a stable generator output PW _GEN without supplying steam to the low-pressure steam turbine unit 21, The operation described above is executed in the transition process from the normal operation state to the bypass operation state. That is, in the present embodiment, after the steam for preventing windage loss is supplied to the low-pressure steam turbine unit 21 in the transition process from the normal operation state to the bypass operation state, the generator output PW _GEN is stabilized in this state (t7). The low pressure steam stop valve 71a and the low pressure steam control valve 71b are closed (t8a).

`` Various modifications ''
In each of the above embodiments, the normal time measurement step (S7) is executed, and then the bypass time measurement step (S9) is executed. However, the normal measurement step (S7) may be executed after the bypass measurement step (S9).

  In the above embodiment, the bypass output estimation step (S10) and the normal output estimation step (S11) are executed, but only the bypass output estimation step (S10) may be executed.

  The steam turbine 20 of the above embodiment has the three steam turbine parts 21, 22, and 23 into which steams having different pressures flow. However, the number of the steam turbine units 21, 22, 23 may be four or more, two, or one. Even in these cases, in the transition process from the normal operation state to the bypass operation state, it is preferable to supply the wind-loss-preventing steam to the steam turbine unit connected to the condenser 51.

  In the above, the rated operation state of the single-shaft combined cycle plant is shown as one form of the normal operation state. However, in this normal operation state, the GTCC rotor 39 rotates at the rated speed, fuel is supplied to the gas turbine 10, and steam is supplied to the steam turbine units 21, 22, and 23 of the steam turbine 20. Is supplied and the steam for any of the steam turbine units 21, 22, 23 is not bypassed. Further, in this normal operation state, the GTCC rotor 39 rotates at the rated rotational speed, the fuel is supplied to the gas turbine 10, and the steam control valves 71 b of the steam turbine units 21, 22, 23 of the steam turbine 20, The state where 72b and 73b are fully opened and the steam is supplied to each steam turbine part 21,22,23 is also included.

  10: Gas turbine, 11: Compressor, 14: Combustor, 19: Gas turbine rotor, 20: Steam turbine, 21: Low pressure steam turbine section, 22: Medium pressure steam turbine section, 23: High pressure steam turbine section, 29: Steam turbine rotor, 30: generator, 31r: generator rotor, 38: power system, 39: GTCC rotor, 40: exhaust heat recovery boiler, 41: low pressure steam generator, 42: medium pressure steam generator, 43: high pressure Steam generating part, 44: Reheating part, 51: Condenser, 52: Feed water line, 53: Feed water pump, 61: Low pressure steam line, 62: Medium pressure steam line, 63: High pressure steam line, 64: High pressure steam recovery 65: Reheat steam line, 66: Medium pressure steam recovery line, 67: Low pressure steam bypass line, 68: Reheat steam bypass line, 69: High pressure steam bypass line, 71b: Low Steam control valve, 72b: Medium pressure steam control valve, 73b: High pressure steam control valve, 77: Low pressure steam bypass valve, 78: Reheat steam bypass valve, 79: High pressure steam bypass valve, 81: Inlet thermometer, 82: Inlet Pressure gauge, 83: Outlet thermometer, 84: Outlet pressure gauge, 85: Atmospheric thermometer, 86: Atmospheric pressure gauge, 87: Revolution meter, 88: Output meter

Claims (8)

A gas turbine, an exhaust heat recovery boiler that generates steam by heat of exhaust gas from the gas turbine, a steam turbine that is driven by steam from the exhaust heat recovery boiler, and power generation by driving the gas turbine and the steam turbine A single-shaft combined cycle plant in which the gas turbine rotor of the gas turbine, the steam turbine rotor of the steam turbine, and the generator rotor of the generator are connected to each other on the same axis. In the turbine output estimation method of
A bypass operation step of supplying fuel to the gas turbine to operate the gas turbine and bypassing the steam supplied to the steam turbine to the steam turbine;
A bypass measurement process for measuring the generator output during the bypass operation process;
Using the generator output obtained in the bypass measurement step, the bypass output estimation step for estimating the gas turbine output;
A turbine output estimation method for a single-shaft combined cycle plant that executes In the turbine output estimation method of the single shaft type combined cycle plant according to claim 1,
The steam turbine has one or more steam turbine parts,
In the bypass operation step, the steam supplied to all the steam turbine units except for the low-pressure steam turbine unit connected to the condenser for returning the exhausted steam to water among the one or more steam turbine units is bypassed. And supplying the steam for preventing windage loss at a flow rate at which the outlet temperature of the low-pressure steam turbine section does not exceed a predetermined upper limit value to the low-pressure steam turbine section, while supplying the remaining steam to the low-pressure steam turbine section. Bypass
In the bypass output estimation step, a steam turbine output generated by driving the low-pressure steam turbine section supplied with the windage-preventing steam is estimated, and the generator output obtained in the bypass measurement step is estimated. Subtracting the steam turbine output from to estimate the gas turbine output,
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to claim 1 or 2,
In the bypass power estimation step, a value obtained by correcting the steam turbine mechanical loss is used as the steam turbine output.
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to claim 1,
The steam turbine has one or more steam turbine parts,
In the bypass operation step, the steam supplied to all the steam turbine units except for the low-pressure steam turbine unit connected to the condenser for returning the exhausted steam to water among the one or more steam turbine units is bypassed. And supplying the steam for preventing windage loss at a flow rate at which the outlet temperature of the low-pressure steam turbine section does not exceed a predetermined upper limit value to the low-pressure steam turbine section, while supplying the remaining steam to the low-pressure steam turbine section. Bypassing all the steam supplied to the low-pressure steam turbine section after the generator output is stabilized,
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to any one of claims 1 to 4,
In the bypass output estimation step, the gas turbine output is estimated using a value obtained by adding a mechanical loss of the generator to the generator output obtained in the bypass measurement step.
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to any one of claims 1 to 5,
A normal operation step of supplying fuel to the gas turbine to operate the gas turbine, and supplying steam to the steam turbine to operate the steam turbine;
A normal measurement step of measuring the generator output during the normal operation step;
A normal output estimation step for estimating a steam turbine output using the gas turbine output estimated in the bypass output estimation step and the generator output obtained in the normal measurement step;
Run the
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to claim 6,
Obtaining environmental conditions of the gas turbine at the time of execution of the measurement process at the time of bypass and at the time of execution of the normal time measurement process
In the normal-time output estimation step, the bypass-time output estimation step is performed using the gas turbine environmental condition during execution of the bypass-time measurement step and the gas turbine environmental condition during execution of the normal-time measurement step. The estimated gas turbine output is converted into a value at the time of execution of the normal time measurement step, and the execution of the normal time measurement step is performed using the gas turbine output at the time of execution of the normal time measurement step obtained by the conversion. Estimating the steam turbine power at the time,
Turbine output estimation method for a single-shaft combined cycle plant. In the turbine output estimation method of the single shaft type combined cycle plant according to claim 6 or 7,
In the normal time output estimating step, the steam turbine output is estimated using a value obtained by adding a mechanical loss of the generator to the generator output obtained in the bypass time estimating step.
Turbine output estimation method for a single-shaft combined cycle plant.

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