CH708485A2 - Systems and methods for de-icing an Einlasssiebs a gas turbine and for dehumidifying air intake filters. - Google Patents

Abstract

A system for defrosting a gas turbine (101) is provided. A branch line is connected to an inlet screen (135). A first line is connected to a stage of the compressor (105) and a first input of the mixer component (185). A second conduit is connected to the exhaust outlet (120) and a second input of the mixer component (185). The second line is designed to extract exhaust gases without increasing the pressure at the exhaust outlet. A third conduit (190) is connected to the outlet of the mixer component (185) and the branch conduit. A method for defrosting a gas turbine inlet strainer (135) includes determining an actual temperature at the inlet strainer (135) and determining a desired temperature at the intake strainer. When the actual temperature at the inlet screen (135) is lower than the target temperature at the inlet screen (135), a first flow rate of air-exhaust mixture necessary to obtain the desired inlet screen temperature is calculated. The method also includes extracting an amount of exhaust gas from the turbine exhaust outlet subsystem (120) without increasing pressure at the turbine exhaust outlet subsystem (120), extracting an amount of air from a compressor stage, and mixing the amount of exhaust gas with the amount Air to produce an air-exhaust mixture that is conveyed to the intake screen (135).

Description

Reference to related applications

This application is a continuation-in-part of US Serial No. 13 / 303,852 filed Nov. 23, 2011.

Field of engineering

The subject matter described herein generally relates to gas turbines and more particularly to methods and systems for preventing icing of gas turbine inlet screens.

General state of the art

Gas turbines typically include a compressor for compressing incoming air, a burner for mixing fuel with the compressed air and for igniting a fuel / air mixture to form a high temperature gas stream, and a turbine section derived from the high-temperature gas stream is driven.

Gas turbines are used worldwide under diverse climatic conditions for the production of electrical power or as mechanical drives for the operation of pumps and compressors. Operation under cold ambient and high humidity conditions often causes ice formation on the components of a turbine inlet filter housing. Often, this ice formation on air filter elements (bird screens, moisture traps, coalescing filters, and filter modules) is severe enough to restrict airflow and cause a fall in intake air pressure over the filter housing, resulting in power loss of the gas turbine or even shutdown. Ice precipitate forms when water, which is taken up as a liquid or solid at a temperature near or below freezing, adheres to most exposed surfaces, causing ice formation. Likewise, ice forms when saturated cooled air comes into contact with colder filter housing surfaces.

A common approach to controlling ice formation is to remove the moisture separators and coalescing filters installed in a weather hood and to heat the ambient air upstream of the air filter modules by means of warm air or spirals, either steam or mixed be supplied from warm water / glycol.

In a typical deicing system of the prior art, exhaust gas is recirculated by means of a bypass valve positioned in the exhaust duct. This allows sufficient warm gases to be constantly returned to the inlet to keep the air temperature at the turbine inlet at least + 40 ° F. This approach has the disadvantage that the pressure at the turbine exhaust outlet is increased, which has a negative effect on the performance of the gas turbine.

Another type of defrosting system utilizes heating coils placed in front of the inlet filters to allow for heating under ambient conditions involving the formation of ice on the air filters, inner filter housing walls as well as downstream turbine components, for example inlet vanes and blades of the first compressor stage, favor. In spiral-based systems, heat is supplied to the coils in the form of a mixture of warm water / glycol or low pressure steam (LP). This approach increases the cost of capital and may adversely affect production output due to the additional restriction of air flow (the pressure drop) caused for example by the heating coils over the operating year.

Another approach is to provide a plurality of heating plates (bundles) provided on or adjacent to the intake air filter housing of the turbine. Each heating plate is provided with one or more electrical resistance heating elements. In addition, a controller for selectively activating the resistance heating elements is provided on each of the heating plates.

Brief description of the invention

The invention provides a solution to the problem of preventing the formation of ice on the inlet grates of the gas turbine without a significant loss of power.

According to one non-limiting embodiment, the invention relates to a method for heating an inlet screen in a gas turbine. The method includes determining an actual intake screen temperature and determining a desired intake screen temperature. If the actual intake screen temperature is lower than the desired intake screen temperature, the method includes calculating a first flow rate of air / exhaust gas mixture necessary to achieve the desired intake screen temperature. The method also includes extracting an amount of exhaust gas from the turbine exhaust outlet subsystem without increasing a pressure at the turbine exhaust outlet subsystem, extracting an amount of air from a compressor stage, and mixing the amount of exhaust gas with the amount of air to produce an air Generate exhaust mixture. The method also includes conveying the air-exhaust mixture to the intake screen, wherein the air-exhaust mixture is conveyed at a flow rate equal to the first flow rate.

The method may include conveying the air-exhaust mixture to the intake screen comprising adjusting an intake screen control valve.

Each of the above methods may include mixing the amount of exhaust gas with the amount of air to produce the air-exhaust mixture, mixing the amount of exhaust gas with the amount of air in an ejector.

Each of the above methods may include adding air to the amount of exhaust gas.

[0014] Each of the above methods may further include: determining an actual compressor inlet temperature, determining a desired compressor inlet temperature; When the actual compressor inlet temperature is lower than the desired compressor inlet temperature, further comprising: calculating a second flow rate of air-exhaust mixture necessary to achieve the desired compressor inlet temperature; extracting an amount of exhaust gas from a turbine exhaust outlet; extracting an amount of air from a compressor stage; mixing the amount of exhaust gas with the amount of air to produce the air-exhaust mixture; and conveying the air-exhaust mixture to a compressor inlet; wherein the air-exhaust mixture has a flow rate equal to the second flow rate.

Each of the above methods may include conveying the air-exhaust mixture to the intake screen comprising adjusting an intake screen control valve.

Any of the above methods may include that the desired intake screen temperature is sufficient to defrost the intake screen.

Any of the above methods may include where the desired intake screen temperature is sufficient to dehumidify the intake air filter.

In another embodiment, a system includes a compressor, a turbine with an exhaust gas outlet, and an intake screen. A branch line is connected to the inlet screen. A mixer component having a first input, a second input, and an output is provided. A first line is connected to a stage of the compressor and the first input of the mixer component. A second conduit is connected to the exhaust outlet and the second inlet of the mixer component, the second conduit adapted to extract exhaust gases without increasing the pressure at the exhaust outlet. A third conduit is connected to the outlet of the mixer component and the branch conduit.

The system may further include a first control valve disposed on the first conduit.

Each of the above systems may further include a first block valve disposed on the second conduit.

Each of the above systems may further include a second control valve disposed on the third conduit.

Each of the above systems may further include an IBH system connected to the compressor and an IBH branch line connected to the third line and the IBH system.

Each of the above systems may further comprise a burner connected to the compressor and the turbine.

Each of the above systems may further comprise a heat recovery steam generator connected to the turbine.

In another embodiment, a system is provided that includes a compressor, a combustion system, a turbine, and a turbine exhaust outlet subsystem. The system may include a compressor inlet connected to the compressor and an inlet strainer connected to the compressor inlet. A branch line is connected to the inlet screen. A compressor extraction subsystem designed to extract air from the compressor is connected to a stage of the compressor. An exhaust gas extraction subsystem configured to extract exhaust gases without increasing the pressure at the exhaust gas outlet subsystem is connected to the turbine exhaust outlet subsystem. A mixer component is connected to the compressor extraction subsystem and the exhaust extraction subsystem. The mixer component is configured to mix the air and the exhaust gases to produce an air-exhaust mixture. The system includes a first conduit connected to the mixer component and the branch conduit and delivering the air-exhaust mixture to the branch conduit.

The above system may further include: an inlet heat tapping branch pipe connected to the compressor inlet; and a second conduit connected to the mixer component and the inlet heat tapping branch conduit.

Each of the above systems may further comprise: a first control subsystem disposed on the second conduit; a second control subsystem connected to the exhaust extraction subsystem; and a third control subsystem connected to the compressor extraction subsystem.

Each of the above systems may further include a mechanical load connected to the turbine.

Each of the above systems may further include a steam turbine connected to the turbine exhaust outlet subsystem.

Brief description of the drawings

Other features and advantages of the present invention will become apparent from the following more particular description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of certain aspects of the invention. <Tb> FIG. 1 <SEP> is a schematic of one embodiment of a system for defrosting a gas turbine inlet strainer. <Tb> FIG. 2 <SEP> is a schematic of one embodiment of a control system used in a system for defrosting a gas turbine inlet strainer. <Tb> FIG. 3 <SEP> is an alternate embodiment of a system for defrosting a gas turbine inlet strainer. <Tb> FIG. 4 <SEP> is an alternate embodiment of a system for defrosting a gas turbine inlet strainer. <Tb> FIG. FIG. 5 is a flowchart illustrating a method of defrosting a gas turbine inlet strainer. FIG. <Tb> FIG. FIG. 6 is a flowchart illustrating additional steps in a method of defrosting a gas turbine inlet strainer.

Detailed description of the invention

In Fig. 1, an embodiment of a gas turbine system 100 is shown with an inlet screen deicing function. The gas turbine system 100 may include one or more gas turbines 101. Each gas turbine 101 has a compressor 105 that compresses an incoming airflow. The compressor 105 delivers the compressed air stream to a combustion subsystem 110 where the compressed air stream is mixed with a compressed fuel stream and the mixture is ignited to produce a combustion gas stream. The combustion gas stream in turn is supplied to a turbine 115 and drives the turbine 115 to produce mechanical work. The mechanical work generated in the turbine 115 drives the compressor 105 and an external consumer, such as an electric generator. The combustion gas stream may be exhausted via an exhaust outlet subsystem 120 to an exhaust pipe or otherwise disposed of.

The gas turbine 101 may include a compressor inlet subsystem 125 having an articulated inlet guide vane 130 extending in the gas turbine 101 in a substantially circumferential direction.

The gas turbine 101 may include an inlet screen 135 or a filter housing including filter assemblies having a plurality of inlet air filters 136 that remove moisture and particulate matter, such as dust and dirt, from the air that is channeled to the gas turbine 101.

The gas turbine system 100 may also include a compressor bypass line 140 (a first line) that is used to extract an amount of compressed air from a stage of the compressor 105. Associated with the compressor bypass line 140 is a first line control subsystem 145, which may include a first line control valve 150, and a first line current sensor 155, 155. The gas turbine system 100 further includes an exhaust outlet bypass 160 (a second conduit) and a second conduit control subsystem 165, 165. The exhaust outlet bypass 160 extracts an amount of exhaust gases from the exhaust outlet subsystem 120 without increasing the pressure at the exhaust outlet subsystem 120 (eg, by suction). The second line control subsystem, 165, may include a second line blocking valve, 170. Exhaust gases flowing through the exhaust outlet bypass 160 may be mixed with filtered air from the filtered air source 175. The amount of filtered air is controlled by the filtered air control valve, 180. An alternative source of unfiltered air, 176, is unfiltered and is controlled with the control valve 181 and may be mixed with the flow in the exhaust gas outlet bypass 160.

Air from the compressor bypass 140 and exhaust from the exhaust outlet bypass 160 - which may be mixed with filtered or unfiltered air but need not be mixed - are mixed in the mixer component 185, such as an ejector. As those skilled in the art know, ejectors are a type of jet pump that does not require moving parts to pump out a liquid or gas from a particular area. These pumps use their design to transfer energy from one fluid to another via the Venturi effect. In the ejector, the driving fluid (pressurized air from the compressor 105) flows through the nozzle of the ejector and converts the pressure energy into a jet. The result of this is that the fluid at the front of the jet is displaced, creating a region of low pressure at the exit of the nozzle. Exhaust gases are sucked in through the inlet port of the ejector, creating a suction flow. The compressed air and exhaust gases are mixed as they move through the diffuser of the ejector. The velocity energy of this air-exhaust mixture is converted into pressure energy, so that the air-exhaust mixture is discharged from the ejector with a back pressure that is stronger than the suction pressure.

The mixture of air and exhaust gases is conveyed to a third conduit 190. Part of the mixture of air and exhaust gases may be conveyed through an inlet heat bleed line (IBH line 195) to an inlet heat bleed branch line (IBH branch line 200). The amount of the mixture of air and exhaust gases conveyed to the IBH branch 200 is controlled by means of an IBH bypass control valve 205. A portion of the air-exhaust mixture may also be conveyed through an inlet wire 210 to a defrost branch 215. The amount of the air-exhaust mixture conveyed to the defrost branch line 215 is controlled by means of an intake screen control valve 220. The mixture of air and exhaust gases is further combined with ambient air from an ambient air intake 225. In the event that all of the flow in the third line 190 is conveyed to the defrost branch line 215, the alternative unfiltered air source 176 may be used to minimize the load on the inlet air filters 136.

In operation, compressed air from one stage of the compressor 105 is conveyed (at a temperature Tcsn) to the mixer component 185. Exhaust gases (at a temperature Tex) are extracted from the exhaust gas outlet subsystem 120 due to the lower pressure generated at the mixer component 185 (e.g., at an ejector) without increasing the pressure at the exhaust gas outlet subsystem 120. The amount of compressed air and exhaust gases conveyed to the mixer component 185 depends on the target intake port temperature 135 (target Tis), the actual intake port 135 temperature (actual Tis), the target intake air filter temperature 136 (Desired Tfilter), the desired temperature at the compressor inlet (target Tinlet) of the actual temperature at the compressor inlet subsystem 125 (actual Tinlet) and the ambient temperature (Tamb). The relative amounts of air or gas are calculated using mass flow calculations and are controlled by the first conduit control valve 150, the second conduit block valve 170, the IBH bypass control valve 205, and the inlet strainer control valve 220.

As shown in FIG. 2, the positions of the first-line control valve 150, the second-line control valve 170, the IBH bypass control valve 205, the filtered-air control valve 180, the control valve 181, and the Inlet screen control valve 220 is controlled by a control unit 235. The control unit 235 may also receive inputs from the first line current sensor 155, among other things. The control unit 235 may be an independent control unit or integrated into a gas turbine control system.

An example of a gas turbine control system is the General Electric Company's Speedtronic ™ Mark VI ™ Control System, which is designed to meet all gas turbine control requirements, including speed and load control functions designed to control the fuel flow under part load conditions. and a temperature controller that controls the fuel flow to a maximum that is consistent with achieving nominal firing temperatures and that controls airflow across the inlet fins. The Mark VI ™ control system also handles ancillary sequencing to enable fully automatic start, shutdown and cool down. The base system includes protection of the gas turbine against adverse operating conditions and reporting abnormal conditions. Thus, the control system performs numerous functions, including fuel, air and emissions control, sequencing of fuel and ancillary equipment to start, shut down and cool down, synchronizing and balancing the generator and system, monitoring all turbine and control systems Optional features and protection against unsafe and adverse operating conditions. These functions are all performed in an integrated manner to implement the desired preprogrammed and / or operator input control philosophy.

In another embodiment, illustrated in FIG. 3, the compressor bypass line 140 may be connected to the compressor outlet 221. Compressed air from the compressor outlet 221 is mixed with exhaust gases that are extracted by suction from the exhaust outlet subsystem 120. This may be done using a mixer component 185, such as an ejector.

In another embodiment, illustrated in FIG. 4, the second conduit (exhaust outlet bypass 160) may be a large diameter conduit having a block valve 226 and a control valve 230. Exhaust gases are typically under a pressure of about 12 inches H20 in a combination cycle design. The positive pressure relative to the ambient pressure is the driving force to transport the exhaust gas stream fraction to the defrost branch line 215. In view of the relatively low delivery pressure of the exhaust gas, it is believed that this bypass channel has a flow area of, for example, about 30% of the flow area of exhaust outlet bypass 160 leading from the gas turbine exhaust outlet to the inlet of the heat recovery steam generator to receive the necessary bypass flow.

In Fig. 5, a method 300 for deicing an inlet screen 135 of a gas turbine 101 is shown.

In step 305, the method 300 determines an actual temperature at the inlet screen 135.

In step 310, the method 300 determines a desired inlet screen 135 temperature. The desired inlet screen 135 temperature may be a temperature sufficient to de-ice the inlet screen 135 or to dehumidify the inlet air filters 136 to facilitate formation to prevent ice or water droplets.

In step 315, the method 300 determines whether the actual temperature at the inlet screen 135 is lower than the target temperature at the inlet screen 135. If the actual temperature at the inlet screen 135 is lower than the target temperature at the inlet screen 135, then The following additional steps are included in the procedure.

In step 316, the method 300 determines the exhaust gas temperature.

In step 317, method 300 determines the compressor stage temperature.

In step 320, the method 300 calculates a first flow rate of an exhaust gas-air mixture necessary to reach the target temperature at the inlet screen 135.

In step 325, method 300 extracts an amount of exhaust gas from the turbine exhaust outlet by suction.

In step 330, the method 300 mixes the amount of exhaust gas with the amount of air to produce an air-exhaust mixture. The air-exhaust mixture can also be mixed with filtered air.

In step 335, the method 300 extracts an amount of air from a compressor stage.

In step 340, the method 300 mixes the exhaust or air-exhaust mixture with air from a compressor stage. Step 340 may be performed with an ejector.

In step 345, the method 300 advances the air-exhaust mixture at a flow rate equal to the first flow rate to the intake screen. This can be done by adjusting an inlet screen control valve 220.

FIG. 6 shows additional steps 350 that may be performed by the method 300.

In step 355, the method 300 determines an actual temperature at the compressor inlet subsystem 125.

In step 360, the method 300 determines an actual temperature at the compressor inlet subsystem 125.

In step 365, the method 300 determines if the actual temperature at the compressor inlet subsystem 125 is lower than the setpoint temperature at the compressor inlet subsystem 125. If the actual temperature at the compressor inlet subsystem 125 is lower than the setpoint temperature. Temperature at the compressor inlet subsystem 125, then the method 300 performs the following additional steps.

In step 370, the method 300 calculates a second flow rate of air-exhaust mixture necessary to achieve the desired temperature at the compressor inlet subsystem 125.

In step 375, method 300 extracts an amount of exhaust gas from a turbine exhaust outlet without increasing the pressure at the turbine exhaust outlet.

In step 380, method 300 extracts an amount of air from a compressor stage;

In step 385, the method 300 mixes the amount of exhaust gas with the amount of air to produce an air-exhaust mixture; and

In step 390, the method 300 advances the air-exhaust mixture at a flow rate equal to the second flow rate to the compressor inlet.

The method 300 allows the control of the temperature at the defrost branch line 215 and the IBH branch line 200 to avoid icing of the intake screen and to optimize the performance of the gas turbine system 100. This is done without increasing the pressure at the exhaust outlet, thereby avoiding a detrimental effect on performance.

Where the definition of terms deviates from the conventional use of the term, the applicant intends to use the definitions given below, unless expressly stated otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Where the definition of terms differs from the conventional use of the term, the Applicant intends to use the definitions set forth herein unless expressly stated otherwise. The singular forms "one, one, one" and "the, the, the" are meant to include the plural forms unless the context expressly indicates otherwise. It should be understood that the terms first, second, etc. may be used to describe various elements, but that these elements should not be limited by these terms. These terms are only used to distinguish one element from the other. The term "and / or" includes without exception any combination of one or more of the associated listed items. The terms "coupled to" and "connected to" include a direct or indirect connection.

This specification uses examples to describe the invention, including the best mode for carrying it out, and to enable those skilled in the art to practice the invention, including the manufacture and use of devices and systems, and include the execution of included methods. The protective field of the invention is defined by the claims and may include other examples which may be obvious to those skilled in the art. These other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they have equivalent structural elements.

A system for defrosting a gas turbine is provided. A branch line is connected to an inlet screen. A first line is connected to a stage of the compressor and a first input of the mixer component. A second conduit is connected to the exhaust outlet and a second input of the mixer component. The second line is designed to extract exhaust gases without increasing the pressure at the exhaust outlet. A third conduit is connected to the outlet of the mixer component and the branch conduit. A method for defrosting a gas turbine inlet strainer includes determining an actual temperature at the inlet strainer and determining a target temperature at the intake strainer. If the actual temperature at the inlet screen is lower than the target inlet screen temperature, a first flow rate of air-exhaust mixture necessary to maintain the desired inlet screen temperature is calculated. The method also includes extracting an amount of exhaust gas from the turbine exhaust outlet subsystem without increasing a pressure at the turbine exhaust outlet subsystem, extracting an amount of air from a compressor stage, and mixing the amount of exhaust gas with the amount of air to produce an air To produce exhaust mixture, which is conveyed to the intake screen.

LIST OF REFERENCE NUMBERS

[0068] <tb> 100 <SEP> Gas Turbine System (5) <tb> 101 <SEP> Gas Turbine (6) <tb> 105 <SEP> Compressors (6) <Tb> 110 <September> combustion subsystem <tb> 115 <SEP> Turbine (3) <tb> 120 <SEP> Exhaust Outlet Subsystem (6) <tb> 125 <SEP> Compressor inlet subsystem (9) <130> <SEP> hinged inlet guide vane assembly <tb> 135 <SEP> inlet strainer (13) <tb> 136 <SEP> intake air filter (4) <tb> 140 <SEP> compressor bypass line (4) <tb> 145 <SEP> First Line Control Subsystem <tb> 150 <SEP> First Line Control Valve (3) <tb> 155 <SEP> First Line Current Sensor (2) <tb> 160 <SEP> Exhaust bypass line (7) <tb> 165 <SEP> Second Line Control Subsystem (2) <tb> 170 <SEP> Block valve for the second line (3) <Tb> 175 <September> Filters air source <tb> 176 <SEP> alternative source of unfiltered air (2) <tb> 180 <SEP> Filter Air Control Valve (2) <tb> 181 <SEP> Control Valve (2) <tb> 185 <SEP> Mixer component (5) <tb> 190 <SEP> third line (2) <Tb> 195 <September> IBH line <tb> 200 <SEP> IBH branch line (3) <tb> 205 <SEP> IBH Bypass Control Valve (3) <Tb> 210 <September> Einlasssiebleitung <tb> 215 <SEP> De-icing branch pipe (5) <tb> 220 <SEP> Intake Strainer Control Valve (4) <tb> 221 <SEP> Compressor outlet (2) <Tb> 225 <September> Umgebungsluftansaugung <Tb> 226 <September> block valve <Tb> 230 <September> control valve <tb> 235 <SEP> Control Unit (3) <300> <SEP> Method (23) Method for de-icing an inlet screen <tb> 305 <SEP> step - determines an actual temperature at the inlet screen <tb> 310 <SEP> step - determines a target temperature at the inlet screen <tb> 315 <SEP> step - determines whether the actual temperature at the inlet screen 135 is lower than the target temperature at the inlet screen <tb> 316 <SEP> Step - determines the exhaust gas temperature <tb> 317 <SEP> Step - determines the compressor stage temperature <tb> 320 <SEP> step - calculates the first flow rate of an exhaust gas-air mixture needed to reach the desired inlet screen temperature <tb> 325 <SEP> Step - Extracts a quantity of exhaust gas from the turbine exhaust outlet by suction <330> Step - mixes the amount of exhaust gas with the amount of air to produce an air-exhaust mixture <tb> 335 <SEP> Step - extracts a lot of air from a compressor stage <tb> 340 <SEP> Step - mixes the exhaust gas or air-exhaust mixture with air from a compressor stage <tb> 345 <SEP> Step - conveys the air-exhaust mixture to the intake screen at a flow rate equal to the first flow rate <tb> 350 <SEP> additional steps <tb> 355 <SEP> Step - determines an actual temperature at the compressor inlet subsystem <tb> 360 <SEP> step - determines a target temperature at the compressor inlet subsystem <365> step </ b> - determines whether the actual temperature at the compressor inlet subsystem 125 is lower than the desired temperature at the compressor inlet subsystem 125. <tb> 370 <SEP> Step - calculates a second flow rate of air-exhaust mixture needed to reach the desired temperature at the compressor inlet subsystem Step 375 extracts a quantity of exhaust gas from a turbine exhaust outlet without increasing the pressure at the turbine exhaust outlet <tb> 380 <SEP> Step - extracts a lot of air from a compressor stage Step 385 mixes the amount of exhaust gas with the amount of air to produce an air-exhaust mixture <tb> 390 <SEP> Step - conveys the air-exhaust mixture at a flow rate equal to the second flow rate to the compressor inlet

Claims (10)

A method of heating an inlet strainer and an inlet air filter in a gas turbine, the method comprising: Determining an actual intake screen temperature; Determining a desired intake screen temperature; if the actual intake screen temperature is lower than the target intake screen temperature, further include: Calculating a first flow rate of air-exhaust mixture necessary to reach the desired intake screen temperature; Extracting an amount of exhaust gas from a turbine exhaust outlet subsystem without increasing pressure at the turbine exhaust outlet subsystem; Extracting a quantity of air from a compressor stage; Mixing the amount of exhaust gas with the amount of air to produce an air-exhaust mixture; and Conveying the air-exhaust mixture to the intake screen, wherein the air-exhaust mixture is conveyed at a flow rate equivalent to the first flow rate. 2. The method of claim 1, wherein conveying the air-exhaust mixture to the intake screen comprises adjusting an intake screen control valve. 3. The method of claim 1, wherein mixing the amount of exhaust gas with the amount of air to produce the air-exhaust mixture comprises mixing the amount of exhaust gas with the amount of air in an ejector. 4. The method of claim 1, further comprising adding air to the amount of exhaust gas. 5. The method of claim 1, further comprising: Determining an actual compressor inlet temperature; Determining a desired compressor inlet temperature; if the actual compressor inlet temperature is lower than the desired compressor inlet temperature, further include: Calculating a second flow rate of air-exhaust mixture necessary to achieve the desired compressor inlet temperature; Extracting an amount of exhaust gas from a turbine exhaust outlet; Extracting a quantity of air from a compressor stage; Mixing the amount of exhaust gas with the amount of air to produce an air-exhaust mixture; and Conveying the air-exhaust mixture to a compressor inlet, wherein the air-exhaust mixture is conveyed at a flow rate equal to the second flow rate. 6. The method of claim 5, wherein conveying the air-exhaust mixture to the compressor inlet comprises adjusting a compressor inlet control valve. The method of claim 1, wherein the desired intake screen temperature is sufficient to de-ice the intake screen. 8. The method of claim 1, wherein the desired intake screen temperature is sufficient to dehumidify the intake air filter. 9. System comprising: a compressor; a turbine with an exhaust outlet; an inlet screen; a branch line connected to the inlet screen; a mixer component having a first inlet, a second inlet and an outlet; a first conduit connected to a stage of the compressor and the first inlet of the mixer component; a second conduit connected to the exhaust gas outlet and the second inlet of the mixer component, the second conduit being configured to extract exhaust gases by suction; and a third conduit connected to the outlet of the mixer component and the branch conduit. 10. System comprising: a compressor; a combustion system; a turbine; a turbine exhaust system; a compressor inlet connected to the compressor; an inlet screen connected to the compressor inlet; a branch line connected to the inlet screen; a compressor extraction subsystem connected to a stage of the compressor, the compressor extraction subsystem configured to extract air from the compressor; an exhaust gas extraction subsystem connected to the turbine exhaust outlet subsystem configured to extract exhaust gases during intake; a mixer component coupled to the compressor extraction subsystem and the exhaust extraction subsystem, wherein the mixer component is configured to mix the air and exhaust gases to produce an air-exhaust mixture; and a first conduit connected to the mixer component and the branch conduit conveying the air-exhaust mixture to the branch conduit.