JP2004108379A - Gas turbine plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent vanes or the equipment of a gas turbine from being exposed to an excessively high temperature and thereby to prevent the surging of a compressor at a sudden stop of the spray of an evaporative coolant, in a gas turbine for cooling intake air by spraying the evaporative coolant into the intake air. <P>SOLUTION: At the sudden stop of the spray of the evaporative coolant, a fuel flow rate is made low and an amount of the intake air taken into the compressor is reduced automatically to a level at a time when no evaporative coolant is sprayed. <P>COPYRIGHT: (C)2004,JPO

Description

The present application has a function of spraying evaporative coolant in front of a compressor in a power / power generation gas turbine plant having a gas turbine, which is unnecessary for gas turbines and compressors when coolant spray suddenly stops. Related to control to avoid load.

Technology background

Recently, gas turbines for power generation are being widely used in combined cycle systems and the like.

However, in a gas turbine plant, when the intake air temperature in summer increases, the air density decreases and the intake mass decreases, but the compression work of the compressor does not change significantly because the intake air volume does not decrease. On the other hand, the work generated by the expansion of the combustion gas is reduced by the reduction of the intake mass. Therefore, the output of the gas turbine is greatly reduced.

方法 As this improvement, many methods of spraying evaporative coolant such as water or liquid air into the intake air have been proposed.

If the evaporative coolant spray stops suddenly, the gas turbine blades, etc. are exposed to a higher temperature than the specification, and the compressor may be surging. It is described below.

場合 When the evaporative coolant is flowing into the intake air, since the temperature in the compressor has dropped, it is possible to feed more intake air, and a large amount of fuel is being sent to it. However, if the intake air cooling collapses at a stretch, it becomes difficult for the compressor to take in a large amount of intake air, as during intake air cooling.On the other hand, in a gas turbine combustor, the fuel becomes excessive with respect to the intake air, and the combustion temperature rises. Will rise sharply.

水 When water droplets evaporate in the compressor, there is a margin in the compressor stage after the evaporation point due to the increase in density due to the temperature drop of the intake air. Therefore, by adjusting the angle of the IGV and the variable stationary vane on the compressor inlet side to increase the compressor inflow, the gas turbine output can be further increased. However, if the evaporative coolant is stopped in this state, the volume of the intake air is increased by the high temperature even if the intake air has substantially the same mass, so that the load on the compressor is increased and surging is likely to occur. There was no fundamental consideration to avoid them.

In the present application, when the evaporative coolant spray is suddenly stopped, the gas turbine blades and the like are prevented from being exposed to a higher temperature than the specification and the compressor is prevented from surging.

The present invention includes a compressor that compresses air, a gas turbine that receives compressed air from the compressor, burns fuel and drives the combustion gas, and a device that converts generated power of the gas turbine into electric power or the like. In a gas turbine plant that cools intake air by spraying evaporative coolant onto the evaporator, the evaporative coolant evaporates before and inside the compressor, and when the spray amount of the evaporative coolant suddenly decreases from the spray set amount, The gas turbine plant is characterized in that the amount of fuel supplied to the turbine is automatically reduced to the amount of fuel supplied under operating conditions in which the evaporative coolant is not sprayed.

The present invention also includes a compressor that compresses air, a gas turbine that receives compressed air from the compressor, burns fuel, and is driven by the combustion gas, and a device that converts power generated by the gas turbine into electric power or the like. In a gas turbine plant that cools the intake air by spraying the evaporative coolant onto the intake air, the evaporative coolant evaporates before and inside the compressor, and when the spray amount of the evaporative coolant suddenly decreases from the spray set amount, The gas turbine plant is characterized in that the IGV angle and / or the angle of the stationary blade are automatically changed to an angle under operating conditions in which the evaporative coolant is not sprayed.

(1) It is possible to prevent the gas turbine blades and equipment from being exposed to excessively high temperatures when the spray of the evaporative coolant is suddenly stopped. (2) When the spray of the evaporative coolant is suddenly stopped, surging of the compressor can be prevented.

(4) In a gas turbine plant, even if the spray amount of the evaporative coolant for cooling the intake air suddenly decreases, the adverse effect caused by the fuel supply amount adjustment and the automatic change of the blade angle is avoided.

FIG. 2 shows an embodiment of the present invention. The signal indicating that the spray amount has been reduced by the pressure sensor 69 enters the control panel 73 and determines an emergency state. Then, the control panel 73 automatically outputs a signal to the fuel adjusting valve 72 to reduce the fuel flow rate to a set value (a state in which water spray is not performed), and a state in which the IGV actuator 70 is not sprayed with an IGV angle (in terms of flow rate). A signal for changing the angle of the movable stationary blade to the angle of the movable stationary blade actuator 71 is output to the movable stationary blade actuator 71 so as to change the angle of the movable stationary blade to a state in which water spray is not performed (the direction of decreasing the flow rate).

With this configuration, the blades and equipment of the gas turbine 65 can be prevented from being exposed to an excessively high temperature, and the intake of the compressor 64 can be suppressed, so that surging can be prevented. A signal is sent to the fuel adjustment valve 72, the IGV actuator 70, and the movable stationary blade actuator 71 in order to return to a set amount in a state where water is not sprayed. The set amount can be set manually, and the operating condition can be set using a program. It can also be set automatically from.

FIGS. 3A and 3B are views of a nozzle installed in a splitter in the silencer, which is near the silencer 2 in FIG. 3A is a plan view, and FIG. 3B is an enlarged view of a part of FIG. 3A. The splitter 92 is a component of the silencer 91. The water pipes 93 and 94 for spraying and the air pipe 94 are arranged in a splitter 92. A nozzle 96 for spraying water is provided on a side surface of the splitter 92 on the compressor side. The nozzle 96 is directly attached to the air pipe 94. Water droplets are sprayed through the nozzle 96. In FIG. 9B, the piping is fixed to the splitter 92 side by brackets 99 and 100. With these configurations, there is no need to provide a separate space for pipes, and the intake passage resistance due to the nozzles exposed to the air passage is extremely small.

And the sound absorbing material of FIG. 3b is preferably at least between the pipe and the perforated plate. With this arrangement, noise can be absorbed.

Ｂ In FIG. 3b, a water-repellent sound-absorbing material is used as the sound-absorbing material, but this does not absorb water when wet intake air flows. When water is absorbed, the sound absorbing performance decreases, but by using a water-repellent sound absorbing material, the sound absorbing performance can be prevented from lowering. In the case where wet intake air flows, for example, an intake air cooler is provided in front of the silencer in FIG. 1, but depending on the cooling conditions, wet intake air may occur. In addition, as a countermeasure in such a case, it is preferable to use a silencer splitter or a material whose wall surface is subjected to a corrosion-resistant material or a corrosion-resistant treatment, in addition to the water-repellent sound-absorbing material.

Also, it is desirable that the spray of the evaporative coolant is as uniform as possible when viewed in a plane perpendicular to the flow of the intake air from the viewpoint of the partial surging of the compressor and the uniformity of the temperature of the combustor. When spraying the evaporative coolant in the air path before the compressor, the intake air flows at a high speed (20m / sec to 30m / sec) in the air path, so a large air volume is required to spray at the same speed. It is. The sprayed water droplets spread around the surrounding air together with the blast air. Therefore, in the case of spraying uniformly in a conical shape, a larger amount of injected air is consumed when the surrounding air speed is high than when the surrounding is still air.

4A and 4B are views of a nozzle for spraying water droplets as viewed from the compressor side. FIG. 4a shows a nozzle arrangement mounted on the splitter side. FIG. 4b is a spray pattern of water droplets emitted from the nozzle of FIG. 4a. The spray pattern is a linear pattern. The nozzle is attached to the air pipe with a pipe screw, and since the screw is kept tightened, the direction of the linear pattern is random, and when viewed locally, water droplets are largely unevenly distributed. The sprayed unevenly distributed water droplets are supplied to a wind path bent at a right angle. Note that an example of the air path bent at a right angle is the air path from the silencer to the compressor in FIGS. 1 and 2. Since the flow of the intake air is largely disturbed in the wind path portion bent at a right angle, the unevenly distributed water droplets are put therein to improve the distribution of the water droplets. In addition, it is naturally preferable not to install a louver for adjusting a flow in a wind path portion bent at a right angle.

In FIG. 5, the spray pattern is a ring pattern, and in FIG. 6, the spray pattern is a pattern sprayed in a dot on the circumference.

噴霧 When spraying in a linear pattern, an annular pattern or a pattern sprayed in a circle on a circle, a part of the evaporative coolant spreads outward, but the distribution of water droplets is extremely uneven. However, when this is sprayed into a passage bent at a right angle, the distribution of the evaporative coolant is improved in the turbulent flow region at the bent portion. And since the spray pattern is linear, annular or dot-like, air for spraying can be reduced.

で は In the drawings of FIGS. 3a, 3b, 4a, 4b, 5 and 6, the number of sets of the splitter of the silencer and the evaporative coolant spray element can be selected according to the conditions.

機器 In the drawings of the embodiments of the present application, devices for converting generated power into electric power and the like, for example, generators are omitted.

It is an example of water spray. It is an embodiment corresponding to the emergency stop of water spray of the present invention. , It is an example of a water spray element arrangement. It is an example of a nozzle arrangement. It is an example of a water spray pattern. It is an example of a water spray pattern. It is an example of a water spray pattern.

Explanation of reference numerals

1,61 Intake chamber 2,62,91 Silencer 3,63,96,112 Nozzle 4,64 Compressor 5,65 Gas turbine 6,66 Waste heat recovery heat exchanger 7,67 Tank 8,68 Pump 9 Intake cooler 10 , 74 Filter 69 Pressure sensor 70 IGV actuator 71 Variable angle stationary blade actuator 72 Fuel control valve 73 Control panel 92, 111 Splitter 93, 94 Water pipe 95 Air pipe 97 Intake duct side wall 98 Water repellent sound absorbing material 99, 100 Bracket 101 Perforated Plate 113 Intake duct upper wall 114, 115, 116 Nozzle spray pattern

Claims (2)

It consists of a compressor that compresses air, a gas turbine that receives compressed air from the compressor, burns fuel, drives the combustion gas, and converts the power generated by the gas turbine into electric power, etc. In a gas turbine plant that cools intake air by spraying water, when the evaporative coolant evaporates before and inside the compressor and the spray amount of the evaporative coolant suddenly decreases from the spray set amount,
A gas turbine plant wherein the amount of fuel supplied to the gas turbine is automatically reduced to the amount of fuel supplied under operating conditions in which the evaporative coolant is not sprayed. It consists of a compressor that compresses air, a gas turbine that receives compressed air from the compressor, burns fuel, drives the combustion gas, and converts the power generated by the gas turbine into electric power, etc. In a gas turbine plant that cools intake air by spraying water, when the evaporative coolant evaporates before and inside the compressor and the spray amount of the evaporative coolant suddenly decreases from the spray set amount,
A gas turbine plant, wherein an IGV angle and an angle of a stationary blade are automatically changed to an angle under operating conditions in which the evaporative coolant is not sprayed.

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