# US 10,480,404 B2 · Method for injecting water into a multistage axial compressor of a gas turbine

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- Number: US 10,480,404 B2
- Document ID: US10480404B2
- Status: Granted
- Kind: B2
- Application number: 13/557,757
- Filed: 2012-07-25
- Published: 2013-01-31
- Granted: 2019-11-19
- Earliest claimed: 2011-07-25
- Assignees: Ansaldo Energia Switzerland AG
- Applicants: Luis Puerta; Marco Micheli; Wolfgang Kappis; Erik Peter Boldt
- Inventors: Luis Puerta; Marco Micheli; Wolfgang Kappis; Erik Peter Boldt
- Web page: https://patentgrep.com/patent/US10480404B2

## CPC

- F02C 3/305: {Increasing the power, speed, torque or efficiency of a gas turbine or the thrust of a turbojet engine by injecting or adding water, steam or other fluids (F01K21/04 takes precedence)}
- F02C 7/1435: {by water injection}
- F04D 29/5846: {cooling by injection}
- F04D 29/705: {Adding liquids}
- F05D 2260/212: by water injection
- F05D 2270/102: caused by working fluid flow velocity profile distortion
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

A method is disclosed for injecting water into a multistage axial compressor of a gas turbine. With low equipment cost, a significant power enhancement can be achieved, even under changing boundary conditions, by water being injected at a plurality of points along the axial compressor, and by the injected water mass flow being controlled at the individual injection points in accordance with ambient conditions and operating parameters of the gas turbine in such a way that an evened-out loading in the individual stages of the axial compressor can be created.

## Claims

### Claim 1

A method for injecting water into a multistage axial compressor of a gas turbine, comprising:
injecting water at a plurality of points along the axial compressor; and
controlling an injected water mass flow at individual injection points in accordance with ambient conditions and operating parameters of the gas turbine for creating an evened-out loading in individual stages of the axial compressor via an analysis of a meridional mean line flow with a droplet evaporation model and a model of blade erosion.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein the injecting of the water is controlled such that more water is injected between the stages of the axial compressor than is injected at other points along the axial compressor.

### Claim 3 (depends on 2)

The method as claimed in claim 2, wherein the axial compressor has a row of variable, or variably opening, inlet guide vanes at an inlet, wherein the injecting of the water is controlled such that the water is injected upstream of the row of variable inlet guide vanes.

### Claim 4 (depends on 3)

The method as claimed in claim 3, comprising:
delivering the water to the injection points by pumps; and
controlling the pumps for controlling the injected water mass flow.

### Claim 5 (depends on 1)

The method as claimed in claim 1, comprising:
delivering the water to the injection points by pumps; and
controlling the pumps for controlling the injected water mass flow.

### Claim 6 (depends on 1)

The method as claimed in claim 1, comprising:
controlling distribution of water to the individual injection points by control valves in corresponding feed lines.

### Claim 7 (depends on 1)

The method of claim 1, wherein the analysis of the meridional mean line flow with a droplet evaporation model is performed such that the meridional mean line flow is analyzed based on wet compression effects of temperature lowering and of an increase in a steam proportion to correct for density and meridional velocity; and wherein the model of blade erosion is based on experimentally verified algorithms for predicting erosion rate of blades of the axial compressor.

### Claim 8

A method for injecting water into a multistage axial compressor of a gas turbine, comprising:
injecting water at a plurality of points along the axial compressor;
controlling an injected water mass flow at individual injection points in accordance with ambient conditions and operating parameters of the gas turbine for creating an evened-out loading in individual stages of the axial compressor; and
controlling the injected water mass flow via an analysis of a meridional mean line flow with a droplet evaporation model.

### Claim 9 (depends on 8)

The method as claimed in claim 8, comprising:
calculating evaporation effects blade row by blade row in the analysis; and
considering wet compression effects of a temperature lowering and of an increase in steam proportion in the analysis.

### Claim 10 (depends on 9)

The method as claimed in claim 9, comprising:
predicting an erosion rate with a model of blade erosion.

### Claim 11 (depends on 8)

The method as claimed in claim 8, comprising:
controlling distribution of water to the individual injection points by control valves in corresponding feed lines.

### Claim 12

An injection system for a multistage axial compressor of a gas turbine, comprising:
a plurality of individual injectors which are arranged in series in an axial direction inside the axial compressor for injecting water into a gas passage of the axial compressor; and
an injection control system configured to control a water mass flow to the individual injectors according to an analysis of a meridional mean line flow with a droplet evaporation model and a model of blade erosion.

### Claim 13 (depends on 12)

The injection system as claimed in claim 12, comprising:
a gas turbine control system for the gas turbine, the injection control system being in intercommunication with the gas turbine control system.

### Claim 14 (depends on 13)

The injection system as claimed in claim 13, comprising:
individual feed lines for supplying the injectors with water; and
a control valve for throughflow control arranged in each individual feed line, each control valve being connected to the injection control system.

### Claim 15 (depends on 14)

The injection system as claimed in claim 14, comprising:
pumps for delivering water to the injectors the pumps being connected to the injection control system.

### Claim 16 (depends on 12)

The injection system as claimed in claim 12, comprising:
individual feed lines for supplying the injectors with water; and
a control valve for throughflow control arranged in each individual feed line, each control valve being connected to the injection control system.

### Claim 17 (depends on 16)

The injection system as claimed in claim 16, comprising:
pumps for delivering water to the injectors, the pumps being connected to the injection control system.

### Claim 18 (depends on 16)

The injection system as claimed in claim 16, wherein the axial compressor comprises:
a row of variable, or variably opening, inlet guide vanes at an inlet, at least one of the injectors being arranged upstream of the row of inlet guide vanes.

### Claim 19 (depends on 15)

The injection system as claimed in claim 15, wherein the axial compressor comprises:
a row of variable, or variably opening, inlet guide vanes at an inlet, at least one of the injectors being arranged upstream of the row of inlet guide vanes.

### Claim 20 (depends on 12)

The injection system of claim 12, wherein the analysis of the meridional mean line flow with the droplet evaporation model and the model of blade erosion is configured such that the droplet evaporation model is based on wet compression effects of temperature lowering and of an increase in a steam proportion to correct for density and meridional velocity and the model of blade erosion is based on experimentally verified algorithms for predicting erosion rate of blades of the axial compressor; and
wherein the injection control system is configured to control the water mass flow to the individual injectors according to the analysis of a meridional mean line flow to modulate water volume that is injected so that an erosion rate for blades of the compressor is evenly distributed about multiple blade rows of the blades of the compressor.