Gas turbine with bottoming air turbine cycle

• US 5,442,904 A
• Filed: 03/21/1994
• Issued: 08/22/1995
• Est. Priority Date: 03/21/1994
• Status: Expired due to Term

• Current Assignee: Isaac Shnaid
• Original Assignee: Isaac Shnaid
• Inventors: Shnaid, Isaac
• Primary Examiner(s): Casaregola, Louis J.
• Application Number:
  US08/210,570
• Time in Patent Office: 519 Days
• Field of Search: 60/39.181, 60/39.183, 60/39.511, 60/726, 60/728, 60/39.02
• US Class Current: 60/783
• CPC Class Codes: F02C 6/18 using the waste heat of gas-turbine plants outside the plants themselves, e.g. gas-turbine power heat plants using waste heat as source of energy for refrigeration plants F25B27/02; using the waste heat of a gasturbine for steam generation or in a steam cycle see F01K23/10
• CPC Class Codes: F25B 9/004 the refrigerant being air
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]

Abstract

Gas turbine with a bottoming air turbine cycle. This system comprises a gas turbine and a bottoming air turbine cycle system. The latter includes a gas-to-air heat exchanger, compressed air aftercooler, an air compressor, a hot air turbine, and a cold air turbine. High temperature exhaust gases of the gas turbine pass the heat exchanger heating compressed air delivered by the air compressor. Then hot air expands in the hot air turbine. Part of the air from the compressor is cooled in the aftercooler, and then expands in the cold air turbine. Hot and cold air turbines drive the air compressor and an electric generator or other consumer of mechanic power. After the cold air turbine, air temperature is lower than the ambient temperature. Using it, refrigeration can be provided, including cooling gas turbine compressor inlet air. In this mode, the gas turbine compressor consumes air having stabilized low temperature and stabilized pressure. A special peak load mode of the gas turbine is also available.

Claims

1. Gas Turbine With Bottoming Air Turbine Cycle comprising:

a gas turbine comprising connected in series a compressor, at least one combustor and a turbine for producing shaft mechanical power and hot exhaust gases;

a gas-to-air main heat exchanger comprising means for transferring heat from the gas turbine hot exhaust gases to at least one flow of compressed air to produce hot compressed air;

a line connecting the gas side of the main heat exchanger with an exhaust duct of the gas turbine to supply the hot exhaust gases into the main heat exchanger;

hot air turbine comprising means for producing work by expanding the hot compressed air;

an additional air compressor comprising means for supplying at least one flow of compressed air into the main heat exchanger and for supplying at least two additional flows of compressed air;

lines connecting the additional air compressor with the hot air turbine through an air side of the main heat exchanger to supply the hot compressed air to said turbine;

an aftercooler comprising means for extracting heat from the first additional flow of compressed air;

a cold air turbine comprising means for producing work and refrigerated air by expanding the first additional flow of compressed air;

lines connecting the additional air compressor with the cold air turbine through the aftercooler to supply the first additional flow of compressed air to said turbine;

lines connecting a suction duct of the compressor of the gas turbine with the atmosphere, with an exhaust duct of the cold air turbine, and with the additional air compressor to supply the gas turbine compressor with the atmospheric air, with the refrigerated air after the cold air turbine, and with the second additional flow of compressed air;

a line connecting the exhaust duct of the cold air turbine with external consumers of the cold air;

flow controlling &

vices installed on the lines connected to the gas turbine compressor suction duct, to the cold air turbine inlet duct and to the external consumers of the cold air.

2. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, wherein the additional air compressor, the hot air turbine and the cold air turbine have a common shaft connected with consumer of shaft mechanical power to drive the additional air compressor and said consumer by said turbines.

3. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, wherein the gas side of the main heat exchanger has a bypass line with a flow controlling device.

4. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, wherein the cold air turbine has a bypass line with a flow controlling device.

5. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, wherein an auxiliary aftercooler is inserted in the line connecting the suction duct of the gas turbine compressor with the additional air compressor thereby increasing power output of the gas turbine.

6. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, wherein the main heat exchanger has two sections, their gas sides are connected in series, their air sides are separated and all of them are fed by the flow of compressed air from the additional air compressor thereby increasing quantity of heat transferred to the compressed air and power output of the hot air turbine.

7. Gas Turbine With Bottoming Air Turbine Cycle according to claim 1, comprising means for feeding the exhaust air of the hot air turbine into the gas side of the main heat exchanger thereby further increasing the quantity of heat transferred to the compressed air and power output of the hot air turbine.

8. Method of mechanical power production comprising the following steps:

compressing a first air flow;

heating this air flow;

expanding this air flow with deriving work;

extracting heat from this air flow;

compressing a second air flow;

heating this air flow by the heat extracted from the first air flow;

expanding the second air flow with deriving work;

compressing a third air flow using work derived while expanding took place;

extracting heat and condensed water from this air flow;

expanding this air flow with deriving work.

9. Method of power production according to claim 8, further comprising an additional heating of the second air flow by heat extracted from this air flow after its expanding.

10. Method of power production according to claim 8, wherein the third air flow after expanding extracts heat from the first air flow before its compressing.

11. Method of power production according to claim 8, further comprising an additional compressing of the first air flow using the work derived while the expanding the second and the third air flows took place.