Patent Application
20080047276
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate embodiments of the presently disclosed invention and, together with the description, disclose the principles of the invention.
While specific embodiments of the invention are discussed herein and are illustrated in the drawings appended hereto, the invention encompasses a broader spectrum than the specific subject matter described and illustrated. As would be appreciated by those skilled in the art, the embodiments described herein provide but a few examples of the broad scope of the invention. There is no intention to limit the scope of the invention only to the embodiments described.
According to one embodiment of the invention illustrated in
According to one embodiment of the invention, the compressor 12 may include a single shaft that is coupled to components of the low pressure side 5 and to components of the high pressure side 6 of compressor 12. Structures 1-4 perform the function of compressing the fluid that passes through compressor 12. According to one embodiment of the invention, a bleed line 8 may be provided after the low pressure side 5 side of compressor 12 to supply cooling fluid to a rear of the turbine 18. According to one embodiment of the invention, a bleed line 10 may be provided between structures 2 and 3 to supply cooling fluid to a mid-stage of the turbine 18. According to one embodiment of the invention, a bleed line 18 may be provided after the structure 4 to supply cooling fluid to a front of the turbine 18.
According to one embodiment of the invention, the compressor intercooler 14 may include a heat exchanger or other intercooler that extracts the compressed fluid, such as air or other compressed fluid, from the gas turbine 10 at one or more selected stages within the compressor 12. According to another embodiment of the invention, the compressor intercooler 14 cools the compressed fluid using a cooling fluid, such atmospheric air, water, or other cooling fluid and reintroduces the cooled compressed fluid into the gas turbine 10 at one or more selected stages within the compressor 12. According to one embodiment of the invention, the compressor intercooler 14 may extract the compressed fluid after a sixth stage of the compressor 12 and may reintroduce the cooled compressed fluid before the seventh stage of the compressor 12. According to another embodiment of the invention, the compressor intercooler 14 may extract the compressed fluid after a low pressure side 5 of the compressor 12 and may reintroduce the cooled compressed fluid before the high pressure side 6 of the compressor 12. According to one embodiment of the invention, the compressed fluid may be extracted from the compressor 12 after approximately 50% completion of the compression process. One of ordinary skill in the art will readily appreciate that the compressor intercooler 14 may extract the compressed fluid from any stage of the compressor 12 and may reintroduce the compressed fluid into any stage of the compressor 12.
According to one embodiment of the invention, the compressor intercooler 14 returns the cooled compressed fluid to one or more stages of the compressor 12 that are located at a same stage and/or at a closer stage to the outlet side of the compressor 12, compared to the one or more stages of the compressor 12 from which the compressed fluid is extracted. According to one embodiment of the invention, the compressor intercooler 14 may cool the extracted fluid by approximately 200 degrees Fahrenheit before reintroducing the cooled fluid into the compressor 12. According to another embodiment of the invention, the compressor intercooler 14 may introduce the cooled fluid into the compressor 12 at a temperature that is at least 40% cooler than the extracted fluid. According to another embodiment of the invention, the compressor intercooler 14 may introduce the cooled fluid into the compressor 12 at a temperature that is at least 25% cooler than the extracted fluid. One of ordinary skill in the art will readily appreciate that other amounts of cooling may be provided by the compressor intercooler 14.
According to one embodiment of the invention, the compressor intercooler 14 may be configured to maintain a pressure drop equal to or less than approximately 5 pounds per square inch (psi). According to one embodiment of the invention, the compressor intercooler 14 may be configured to maintain a pressure drop equal to or less than approximately 3.5 psi. One of ordinary skill in the art will readily appreciate that other amounts of pressure drop may be designed into the intercooler 14. Intercooler pressure losses may be mitigated by decelerating the extracted flow to lower velocities with an exit diffuser, thereby reducing the dynamic losses in intercooler components, such as piping and the heat exchanger. According to another embodiment of the invention, one or more stages of the compressor 12 that are located downstream of the return stage (e.g., closer to the outlet side of the compressor 12) may be designed to compensate for any pressure drop that is introduced by intercooler 14.
According to one embodiment of the invention, the compressor intercooler 14 may be configured to extract substantially all of the compressor air flow from the compressor 12, without causing an adverse pressure drop in the compressor 12. According to another embodiment of the invention, the compressor intercooler 14 may be configured to extract up to approximately 80% by volume of the total compressor air flow from the compressor 12, without causing an adverse pressure drop in the compressor 12. According to another embodiment of the invention, the compressor intercooler 14 may be configured to extract up to approximately 40% by volume of the total compressor air flow from the compressor 12, without causing an adverse pressure drop in the compressor 12. According to yet another embodiment of the invention, the compressor intercooler 14 may be configured to extract up to approximately 20% by volume of the total compressor air flow from the compressor 12, without causing an adverse pressure drop in the compressor 12. According to one embodiment of the invention, the configuration of down stream blades may be designed to compensate for a reduced mass flow rate. One of ordinary skill in the art will readily appreciate that other volumes of compressed air flow may be extracted from the compressor 12 without causing an adverse pressure drop in the compressor 12.
According to one embodiment of the invention, the compressor 12 includes an outlet that provides a compressed air flow to combustor 17. According to one embodiment of the invention, the compressed air flow may have an exit temperature of several hundred degrees Fahrenheit at the outlet to compressor 12. According to another embodiment of the invention, the compressed air flow may have an exit temperature of several hundred degrees Fahrenheit at the outlet to compressor 12. According to another embodiment of the invention, the compressed air flow may have an exit temperature of approximately 500 degrees Fahrenheit or higher at the outlet to compressor 12. According to another embodiment of the invention, the compressed air flow may have an exit temperature of approximately 750 degrees Fahrenheit or higher at the outlet to compressor 12.
According to one embodiment of the invention, the combustor 17 receives the compressed air flow and injects fuel 16 into the compressed air flow. The compressed air flow/fuel mixture is ignited to increase the air mass temperature to over 2000 degrees Fahrenheit. According to one embodiment of the invention, the air flow/fuel mixture is ignited on a continuous basis.
According to one embodiment of the invention, the heated and compressed air exits the combustor 17 and expands into the turbine 18, thereby reducing the pressure and temperature of the compressed air and increasing the volume of the compressed air. The airflow through the turbine 18 spins blades that are connected to the shaft 15 through aerodynamic lift. A portion of the shaft power produced by the turbine 18 is used to run the compressor 12 and another portion of the shaft power may be delivered to an electric generator or other load. Remaining thermal energy may be extracted from the exhaust flow by a separate power turbine that in turn is connected to an electric generator or other load.
According to one embodiment of the invention, point A corresponds to ambient pressure and temperature conditions at the inlet to the compressor 12. According to one embodiment of the invention, point Aa corresponds to intermediate pressure and intermediate temperature conditions at an inlet of intercooler 14. According to one embodiment of the invention, point Ab corresponds to intermediate pressure and intermediate temperature conditions at an outlet of intercooler 14. According to one embodiment of the invention, point Bb corresponds to elevated pressure and elevated temperature conditions at the outlet of compressor 12 having a benefit of fluid cooling introduced by the intercooler 14. In particular, the compressor intercooler 14 reduces the compressor 12 discharge temperature compared to point B, which corresponds to elevated pressure and further elevated temperature conditions at the outlet of compressor 12 without the benefit of fluid cooling by the intercooler 14.
According to one embodiment of the invention, point C corresponds to elevated pressure and elevated temperature conditions at the inlet of turbine 18. According to one embodiment of the invention, point D corresponds to ambient pressure and elevated temperature conditions at the outlet of turbine 18.
Due to the addition of the area defined by box 20 onto area defined by box 22, the overall area defined by boxes 20 and 22 is increased when compared to the area defined by box 22 alone. Box 20 signifies the effect of the compressor intercooler 14 on the compressor 12. In particular, the compressor intercooler 14 provides the compressor 12 with higher performance by reducing an amount of work needed to run the compressor 12. The increased overall area contributed by box 20 translates to higher performance of the gas turbine 10.
According to one embodiment of the invention, the compressor intercooler 14 provides improved engine performance and improved cycle performance. According to one embodiment of the invention, the compressor intercooler 14 provides the gas turbine 10 with a power output improvement of between 20 Mega Watts to 30 Mega Watts.
The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of this invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of this invention.
