JP2005090240A - Gas turbine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a thermometer get wet due to sprayed water and temperature near to wet-bulb temperature is detected, in a cooling method for directly spraying water to intake air, and a problem that generation of droplets on an inner wall face of an intake port prevents accurate measurement of intake air temperature, in a method for cooling air by a heat exchanger, although several methods for measuring intake air inlet temperature are proposed, in regard to a gas turbine supplying cooled intake air to a compressor. <P>SOLUTION: The gas turbine A is provided with the compressor 10 compressing intake air supplied from an intake port 11 and discharging the intake air from a discharge port 13, a combustor 30 combusting fuel by the air discharged from the compressor 10, a turbine 40 driven by combustion gas of the combustor 30, and a cooling device 50 cooling the intake air. The discharge port 13 is provided with temperature detection means 61, 62, 63 for detecting the temperature of the air discharged by the compressor 10. Based on the temperature detected by the temperature detection means 61, 62, 63, the temperature of the intake air is measured. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas turbine having a compressor for compressing air and supplying cooled air to the compressor, and more particularly to a structure for measuring the intake air temperature of the compressor.

  Some gas turbines have a system in which cooled air is sucked into a compressor in order to improve output.

  Although the gas turbine is used for power generation, for example, in the summer, although the demand for electric power increases, the atmospheric temperature is high, so that sufficient air cannot be supplied to the compressor at the same temperature. This is the reason why the air supplied to the compressor is cooled.

  The methods for cooling air (intake air) can be broadly classified into a method for spraying water directly on the air and a method for indirectly cooling with a heat exchanger. In either case, the air is cooled at the air inlet of the compressor. However, it is a problem whether the air can be uniformly cooled in the circumferential direction of the inlet.

  This is because if there is a distribution of the intake air temperature in the circumferential direction, the compressor performance is deteriorated. Furthermore, if a large temperature difference occurs in the circumferential direction, the compressor may vibrate. Therefore, a structure is also adopted in which temperature measurement is performed at some points in the circumferential direction at the intake port of the compressor, and whether or not the temperature distribution in the circumferential direction is within a predetermined size is employed. In some cases, the operation specifications are determined such that the operation of the gas turbine is stopped when a temperature difference of a predetermined temperature (for example, 3 degrees) or more is detected.

  Several methods have been proposed for measuring compressor intake air temperature. For example, a device has been proposed in which a thermometer is provided downstream of the air cooler and upstream of the water spray device, and the intake air temperature is monitored by the thermometer. (For example, patent document 1).

  However, when the temperature is measured at the intake port, the following problems occur. That is, in the method of spraying water directly on the intake air, there is a high possibility that the thermometer gets wet with the sprayed water. Then, since the temperature close to the wet bulb temperature is detected, the intake air temperature cannot be measured accurately. In addition, even in a system in which air is indirectly cooled by a heat exchanger, droplets are generated on the inner wall surface of the intake port, and the relative humidity of the intake air increases. Therefore, even in this method, it is impossible to accurately measure the intake air temperature.

  In order to reduce the influence of these droplets and the like as much as possible, it is conceivable to protrude the temperature detector of the thermometer as large as possible inside the intake port. However, when the protrusion length is increased, the thermometer is likely to vibrate due to the air flow, and as a result, the possibility of damaging the thermometer increases.

As mentioned above, the operation of the gas turbine may stop when the temperature distribution in the circumferential direction of the intake port exceeds a certain level. However, because the measurement error of the intake air temperature is large, a relatively small temperature distribution is detected for safety. In some cases, the operation of the gas turbine must be stopped at this point.
Japanese Patent No. 2980095 (pages 9 to 11, FIGS. 1 and 8)

  The problem to be solved by the present invention is to provide a gas turbine that can measure the intake air temperature of a compressor without being affected by the influence of droplets or the humidity of intake air.

In order to solve this problem, a gas turbine according to the present invention compresses intake air supplied from an intake port and discharges it from the discharge port, and burns fuel with the air discharged from the compressor. In a gas turbine comprising a combustor, a turbine driven by combustion gas of the combustor, and a cooling device for cooling the intake air, the temperature of air discharged from the compressor is detected at the discharge port Temperature detecting means is provided, and the temperature of the intake air at the suction port is measured based on the temperature detected by the temperature detecting means.
Since the discharge port is unlikely to be affected by droplets or humidity by the cooling device like the suction port, accurate temperature detection is possible at the discharge port. If the characteristics of the compressor are known, the temperature of the intake air at the suction port can be calculated from the temperature detected at the discharge port. Therefore, it is possible to accurately measure the temperature at the suction port without being affected by droplets or humidity.

  In a gas turbine including a compressor to which cooled intake air is supplied, the intake air temperature can be measured without being affected by droplets at the intake port or the humidity of the intake air. Therefore, the temperature distribution in the circumferential direction of the intake air can be accurately measured.

  In the gas turbine of the present application, the temperature detection means may be provided at a plurality of points in the circumferential direction of the discharge port. Then, the temperature distribution in the circumferential direction of the suction port may be measured based on the temperature detected by the temperature detection means.

  In this case (when temperature detection means are provided at a plurality of points in the circumferential direction), the temperature detection means may be provided at equal angular intervals in the circumferential direction of the discharge port.

  Moreover, you may provide the pressure detection means which detects the pressure of the air discharged from this compressor in this discharge port. Then, the temperature of the intake air at the suction port may be measured based on not only the detected temperature but also the pressure detected by the pressure detection means.

  The compressor may be a centrifugal compressor or an axial flow compressor.

  A plurality of the compressors may be provided. That is, the compressor may have a plurality of stages. The intake air may be compressed in a plurality of stages by the plurality of compressors. In this case, a temperature detecting means may be provided at any one of the plurality of compressors.

  FIG. 1 is a block diagram showing a schematic configuration of a gas turbine A according to an embodiment of the present invention.

  The gas turbine A includes a compressor 10, a combustor 30, a turbine 40, and a cooling device 50.

  This compressor 10 is a centrifugal compressor. The compressor 10 sucks air from the suction port 11 and compresses this air (suction air) by the rotation of the impeller. The compressed air (compressed air) is discharged from the discharge port 13.

  The compressed air from the compressor 10 is sent to the combustor 30. Fuel is supplied to the combustor 30 through a fuel supply pipe 31. The fuel supplied to the combustor 30 is burned with compressed air.

In the combustor 30, combustion gas generated by the combustion of fuel is sent to the turbine 40. Then, the rotation shaft 45 that is the output shaft of the gas turbine A is rotationally driven by the rotation of the turbine 40.
The combustion gas that has rotated the turbine 40 is finally discharged from the exhaust pipe 41 to the atmosphere as exhaust gas.

  The cooling device 50 is a device for cooling the intake air. The cooling device 50 includes a cooling water pipe 51 and a circulator 52. Cooling water flows in the cooling water pipe 51, and this cooling water exchanges heat with the intake air. Thereby, the temperature of intake air is lowered. The cooling water in the cooling water pipe 51 is circulated by a circulator 52. With this cooling device 50, the intake air can be cooled to increase its density, and as a result, the output of the gas turbine A can be improved.

  The discharge port 13 is provided with three probes 61, 62, 63. The three probes 61, 62, 63 are attached at intervals of 120 degrees in the circumferential direction, that is, at equiangular intervals. These probes 61, 62, and 63 are for detecting the temperature and pressure of the discharge air (compressed air) discharged by the compressor 10 at the discharge port 13. That is, the probes 61, 62, and 63 function as temperature detection means and also function as pressure detection means.

  FIG. 2 is a vertical cross-sectional view of the compressor 10 and its peripheral part. In this figure, the probe 61 is shown, but the probes 62 and 63 are not shown. This is because the probes 62 and 63 do not appear on the cross section shown in FIG.

  The rotating shaft 45 is rotatably supported by a bearing 71 in the casing 70. The impeller 12 is fixed to the rotation shaft 45 and rotates integrally with the rotation shaft 45. Reference numeral 14 denotes a stationary blade.

  The intake air cooled by the cooling device 50 is sent from the intake port 11 to the impeller 12 and compressed. The air (compressed air) compressed by the impeller 12 is adjusted in flow by the stationary blade 14. The probe 61 is provided in the vicinity of the stationary blade 14 and on the downstream side thereof.

  The probe 61 has a tip that protrudes slightly inward from the inner wall surface 13 a of the discharge port 13. Thus, since the protrusion length of the probe 61 is short, the probe 61 is not vibrated by the flow of the discharge air.

  The probe 61 detects the temperature of the air compressed by the compressor 10 and the like. In general, when air is compressed, the temperature increases and the relative humidity decreases. The probe 61 detects the temperature of air in a state where the relative humidity is low. Therefore, temperature detection with less error is possible.

  A signal line 61a is connected to the probe 61, and a temperature signal and a pressure signal detected by the probe 61 are transmitted to a control device (not shown) through the signal line 61a.

  The control device can detect the temperature and pressure at the installation location of the probe 61 based on the temperature signal and the pressure signal.

  Generally, if the performance curve of a certain compressor (showing performance characteristics related to air flow rate, pressure, rotation speed, etc., sometimes referred to as “map”) and compressor adiabatic efficiency are known The intake air temperature Tin can be calculated from the discharge air temperature Tout in the compressor, the discharge air pressure Pout, the rotational speed, the atmospheric pressure, and the like. That is, the intake air temperature Tin can be calculated based on the discharge air temperature Tout without directly detecting the intake air temperature Tin.

  For reference, the relationship between the intake air temperature Tin and the discharge air temperature Tout is shown in the following equation.

  In the above equation (Equation 1), the pressure ratio and the compressor adiabatic efficiency appear, but the pressure ratio can be obtained from the discharge port pressure and the atmospheric pressure. It can be determined from the pressure.

  The temperature Tin1 of the suction port 11 can be calculated from the temperature Tout1 and the pressure Pout1 detected by the probe 61 at the place where the probe 61 is installed. The calculated temperature Tin1 best corresponds to a certain point in the circumferential direction of the suction port 11. That is, the intake air temperature Tin1 calculated from the temperature Tout1 detected by the probe 61 installed at a certain point in the circumferential direction of the discharge port 13 best corresponds to the temperature at a specific point in the circumferential direction of the suction port 11. ing.

  It can be known by fluid analysis in the compressor 10 which point in the circumferential direction of the suction port 11 the temperature Tout1 detected by the probe 61 corresponds best.

  3 is a cross-sectional view of the compressor 10, (a) is a cross-sectional view taken along line III (a) -III (a) in FIG. 2, and (b) is III (b) -III in FIG. (b) It is a sectional view taken on line. In other words, (a) is a cross-sectional view at the discharge port 13, and (b) is a cross-sectional view at the suction port 11. In each cross-sectional view, only main members are shown, and other members are omitted.

  As shown in FIG. 3A, the probes 61, 62, and 63 are arranged at equiangular intervals (120 degree intervals). The points N1, N2, and N3 shown in FIG. 3B are points that best correspond to the points where the probes 61, 62, and 63 are installed. That is, the installation point of the probe 61 best corresponds to the point N1 at the suction port 11, the installation point of the probe 62 best corresponds to the point N2 at the suction port 11, and the installation point of the probe 63 is the suction port. 11 corresponds best to the point N3 in FIG.

  Accordingly, it can be considered that the temperature Tin1 at the point N1 at the suction port 11 is calculated from the temperature Tout1 and the pressure Pout1 detected by the probe 61, and the suction port 11 is calculated from the temperature Tout2 and the pressure Pout2 detected by the probe 62. It can be considered that the temperature Tin2 at the point N2 is calculated, and the temperature Tin3 at the point N3 at the suction port 11 can be calculated from the temperature Tout3 and the pressure Pout3 detected by the probe 63.

  In this way, the temperature Tin1 at the point N1, the temperature Tin2 at the point N2, and the temperature Tin3 at the point N3 can be calculated based on the detection signals from the probes 61, 62, and 63. Furthermore, the temperature distribution in the circumferential direction at the suction port 11 can be known from the calculated temperature Tin1, temperature Tin2 and temperature Tin3. If these temperatures (Tin1, Tin2, Tin3) are substantially equal, there is no problem in continuing the operation of the gas turbine A because there is no performance deterioration or vibration in the compressor 10.

  However, when the variations of these temperatures (Tin1, Tin2, Tin3) are large, that is, when the temperature distribution is large, the performance of the compressor 10 may be deteriorated and vibrations may occur, so the operation of the gas turbine A is stopped. You may do it.

  For example, when it is determined that the difference between the maximum temperature and the minimum temperature among these temperatures (Tin1, Tin2, Tin3) is 3 degrees or more, the operation of the gas turbine A may be stopped.

  In the gas turbine A, the pressure of the discharge port 13 is detected at each point where the probes 61, 62, 63 are installed. However, regardless of whether or not the probe is installed, only a certain pressure at the discharge port 13 may be detected. Then, this pressure may be used as a representative pressure at the discharge port 13 to calculate the temperatures of the points N1, N2, and N3 at the suction port 11 from the temperatures detected by the probes 61, 62, and 63.

  FIG. 4 is a measurement diagram showing measurement results obtained by a compressor as an experimental apparatus prepared by the applicant. This compressor is a centrifugal compressor, and the intake air is cooled by a cooling device. Probes serving as temperature detection means were installed at three points (point D1, point D2, and point D3) at equal angular intervals in the circumferential direction at the discharge port. Based on the temperature detected at each of these points (point D1, point D2, point D3), three points (point E1, point E2, point E3) that are spaced apart at equal angular intervals in the circumferential direction at the suction port. The temperature of was calculated. The points D1, D2, and D3 at the discharge port correspond best to the points E1, E2, and E3 at the suction port, respectively.

  In FIG. 4, the horizontal axis represents time, and the vertical axis represents temperature. In FIG. 4, the solid line L1 indicates the detected temperature at the point D1, the alternate long and short dash line L2 indicates the detected temperature at the point D2, the alternate long and two short dashes line L3 indicates the detected temperature at the point D3, and the solid line L4 indicates the calculated temperature at the point E1. The alternate long and short dash line L5 indicates the calculated temperature for the point E2, and the alternate long and two short dashes line L6 indicates the calculated temperature for the point E3.

  Next, an example in which the present invention is applied to a gas turbine having a multistage compressor will be described.

  FIG. 5 is a vertical sectional view of the upper half of the two-stage compressor 80. This compressor 80 is also a compressor for a gas turbine.

  This compressor 80 is also a centrifugal compressor. In the compressor 80, the intake air drawn from the suction port 81 is compressed by the first stage impeller 82A and discharged to the discharge port 83A. The compressed air discharged to the discharge port 83A is further compressed by the second stage impeller 82B and discharged to the discharge port 83B. The compressed air discharged from the discharge port 83B is sent to a combustor (not shown) to burn fuel, and a turbine (not shown) is rotated by the combustion gas generated at this time. Reference numeral 85 denotes a rotation axis.

  In order to calculate the temperature of the intake air at the suction port 81 of the compressor 80, a probe serving as a temperature detection unit may be provided in the discharge port 83A, or a probe serving as a temperature detection unit may be provided in the discharge port 83B. It may be.

  For example, a probe may be installed at the point V1 of the discharge port 83A, the temperature may be detected by the probe, and the temperature at the point U1 of the suction port 81 may be calculated from the detected temperature.

  Further, for example, a probe may be installed at the point W1 of the discharge port 83B, the temperature may be detected by this probe, and the temperature at the point U1 of the suction port 81 may be calculated from the detected temperature.

  That is, when the gas turbine is a type having a plurality of stages of compressors, the gas turbine has a plurality of discharge ports corresponding to the respective compressors. In this case, the temperature detection means (probe) may be installed in any of the plurality of discharge ports.

  That is, it may be installed at the discharge port of the first-stage compressor, may be installed at the discharge port of the final-stage compressor, or may be installed at the discharge port of an intermediate compressor between them.

  If the performance curve and compressor heat insulation efficiency of the compressor provided upstream from the discharge port where the temperature detection means (probe) is installed are known, based on the temperature detected by the temperature detection means (probe), The temperature at the suction port (suction port for supplying air to the first stage compressor) can be calculated.

  Even in such a case, of course, temperature detection means (probes) are installed in a plurality of locations in the circumferential direction of the discharge port, and the temperature distribution in the circumferential direction at the suction port is determined from the detection signals of these temperature detection detections (probes). May be measured.

  In the above, the Example of this invention was described based on FIGS.

  In the above embodiment, the temperature detection means (probes) are installed at equal angular intervals in the circumferential direction at the discharge port of the compressor, but it is not always necessary to have equal angular intervals.

  Further, in the above-described embodiment, it is made to know which angle point in the circumferential direction at the suction port each installation location of the plurality of temperature detection means installed at the discharge port by a technique such as fluid analysis. However, it is not always necessary to know which angle point in the circumferential direction at the suction port each installation location of the plurality of temperature detection means installed at the discharge port corresponds to. This is because, if each temperature detection means is installed at a plurality of locations in the circumferential direction of the discharge port, a plurality of temperatures at the suction port can be calculated from the temperatures detected by each temperature detection means. This is because if a large distribution occurs in the calculated plurality of temperatures, it is estimated that a large temperature distribution in the circumferential direction of the suction port is generated.

  Moreover, the said Example demonstrated the gas turbine provided with a centrifugal compressor. However, the compressor included in the gas turbine need not be a centrifugal type. For example, the present invention can also be applied to a gas turbine including an axial compressor.

  In particular, an axial flow type compressor is often configured in a plurality of stages (multi-stages), but a temperature detection means (probe) may be installed at any outlet corresponding to the compressor of each stage. Based on the temperature detected by the temperature detection means, the temperature of the intake air at the intake port (the intake port that supplies air to the first stage compressor) is calculated, or the temperature distribution in the circumferential direction is measured. Good.

  Since the temperature of the intake air of the compressor can be measured and the temperature distribution in the circumferential direction of the intake port can be measured, it can be applied to the field of gas turbines having a compressor.

2 is a block diagram showing a schematic configuration of a gas turbine A. FIG. It is a longitudinal cross-sectional view of a compressor and its peripheral part. FIG. 3 is a cross-sectional view of the compressor, (a) is a cross-sectional view taken along line III (a) -III (a) in FIG. 2, and (b) is a line III (b) -III (b) in FIG. It is arrow sectional drawing. It is a measurement figure which shows the measurement result in the compressor as an experimental apparatus. It is an upper half longitudinal cross-sectional view of a two-stage compressor.

Explanation of symbols

A Gas turbine 10 Compressor 11 Suction port 12 Impeller 13 Discharge port 13a Inner wall surface 14 Stator blade 30 Combustor 31 Fuel supply pipe 40 Turbine 41 Exhaust pipe 45 Rotating shaft 50 Cooling device 51 Cooling water pipe 52 Circulators 61, 62, 63 Probe 61a Signal line 70 Casing 71 Bearing 80 Compressor 81 Suction port 82A, 82B Impeller 83A, 83B Discharge port 85 Rotating shaft

Claims (7)

A compressor that compresses the intake air supplied from the suction port and discharges the air from the discharge port, a combustor that burns fuel with the air discharged from the compressor, and a turbine that is driven by the combustion gas of the combustor; A gas turbine comprising a cooling device for cooling the intake air,
A gas for measuring the temperature of the intake air at the suction port based on the temperature detected by the temperature detection unit provided with temperature detection means for detecting the temperature of the air discharged from the compressor at the discharge port Turbine.   The temperature detection unit is provided at a plurality of points in the circumferential direction of the discharge port, and the temperature distribution in the circumferential direction of the suction port is measured based on the temperature detected by the temperature detection unit. gas turbine.   The gas turbine according to claim 2, wherein the temperature detection means are provided at equiangular intervals in the circumferential direction of the discharge port.   Pressure detection means for detecting the pressure of the air discharged from the compressor is provided at the discharge port, and the temperature of the intake air at the suction port is measured based on the pressure detected by the pressure detection means. The gas turbine as described in any one of Claims 1 thru | or 3.   The gas turbine according to any one of claims 1 to 4, wherein the compressor is a centrifugal compressor.   The gas turbine according to any one of claims 1 to 4, wherein the compressor is an axial compressor. A plurality of the compressors;
The intake air is compressed into a plurality of stages by the plurality of compressors,
The gas turbine according to any one of claims 1 to 6, wherein the discharge port provided with the temperature detection means is any one of the plurality of compressors.

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