Open brayton bottoming cycle and method of using the same

Patent metadata

Field	Value
Publication number	US-9429069-B2
Application number	US-201313738824-A
Country	US
Kind code	B2
Filing date	Jan 10, 2013
Priority date	Jan 10, 2012
Publication date	Aug 30, 2016
Grant date	Aug 30, 2016

Abstract

According to one embodiment, an open brayton bottoming cycle includes a heat exchanger configured between a compressor and an expander. The heat exchanger is configured to receive heat from a heat source and supply at least a portion of the exhaust heat to an expander using a fluid. The compressor configured to supply compressed fluid to the heat exchanger. The expander has a shaft connected to the compressor and configured to supply energy to the compressor. At least one of the compressor or the expander has an efficiency greater than 80 percent.

First claim

What is claimed is:

1. An open brayton bottoming cycle comprising:
a heat exchanger configured to receive exhaust heat from an engine and supply at least a portion of the exhaust heat to an expander using a fluid, the expander having an inner rotor configured to spin inside an outer rotor;
a compressor having an inner rotor configured to spin inside an outer rotor, the compressor configured to supply compressed fluid to the heat exchanger, a shaft of the expander connected to the compressor;
a motor/generator component configured to initially be activated as a motor and then as speed increases, re-configure to become a generator that receives energy from the shaft of the expander;
a valve configured to supply fluid to the compressor and to trip when the motor/generator component trips and further configured to be throttled when less power is desired; and
a water injector configured to supply a modulated water flow to the compressor, the modulated water flow modulating a volume entering the heat exchanger and the expander,
wherein each of the compressor and expander have an isentropic efficiency greater than between 80 and 95 percent and the compressor tolerates a presence of water in the fluid.

2. The open brayton bottoming cycle of claim 1 , further comprising an intercooler configured between a first stage and a second stage of the compressor, the intercooler configured to cool the fluid and the water.

3. An open brayton bottoming cycle comprising:
a heat exchanger configured to receive exhaust heat from a heat source and supply at least a portion of the exhaust heat to an expander using a fluid;
a compressor configured to supply compressed fluid to the heat exchanger;
a valve configured to supply fluid to the compressor and to trip when a motor/generator component trips and further configured to be throttled when less power is desired; and
a water injector configured to supply a water flow to the compressor;
wherein the expander has a shaft connected to the compressor and configured to supply energy to the compressor,
wherein the heat source is not configured to burn fuel to drive the shaft; and
wherein at least one of the compressor and the expander comprises a gerotor having an isentropic efficiency between 80 and 95 percent at a power rating below 500 kilowatts.

4. The open brayton bottoming cycle of claim 3 , further comprising a motor/generator component configured to initially be activated as a motor and then as speed increases, re-configure to become a generator that receives energy from the shaft of the expander.

5. The open brayton bottoming cycle of claim 3 , further comprising an intercooler configured between a first stage and a second stage of the compressor, the intercooler configured to cool the fluid.

6. The open brayton bottoming cycle of claim 3 , further comprising an intercooler configured between a first stage and a second stage of the compressor, the intercooler configured to cool the water flow.

7. The open brayton bottoming cycle of claim 3 , wherein the water flow comprises hot water.

8. The open brayton bottoming cycle of claim 3 , further comprising a modulator configured to modulate a volume of the water flow entering the heat exchanger and the expander.

9. The open brayton bottoming cycle of claim 3 , wherein the heat source comprises an engine and the heat comprises exhaust heat from the engine.

10. An open brayton bottoming cycle method comprising:
receiving, using a heat exchanger, exhaust heat from a heat source, the heat exchanger supplying at least a portion of the heat to an expander using a fluid;
supplying, using a compressor, compressed fluid to the heat exchanger; and
supplying energy to the compressor using the expander,
tripping a valve when a motor/generator component trips, the valve throttled when less power is desired, wherein the valve is configured to supply fluid to the compressor; and
supplying a water flow to the compressor using a water injector;
wherein the heat source is not configured to burn fuel to drive a shaft connected to the compressor or expander; and
wherein at least one of the compressor or the expander comprises a gerotor having an isentropic efficiency greater than between 80 and 95 percent at a power rating below 500 kilowatts.

11. The open brayton bottoming cycle method of claim 10 , further comprising initially activating the motor/generator as a motor and then as speed increases, re-configuring the motor/generator as a generator that receives energy from the shaft of the expander.

12. The open brayton bottoming cycle method of claim 10 , further comprising cooling the fluid using an intercooler configured between a first stage and a second stage of the compressor.

13. The open brayton bottoming cycle method of claim 10 , further comprising cooling the water flow using an intercooler configured between a first stage and a second stage of the compressor.

14. The open brayton bottoming cycle method of claim 10 , further comprising modulating a volume of the water flow entering the heat exchanger and the expander.

Assignees

• Starrotor Corp
• Texas A & M Univ Sys

Inventors

• Price Dan
• Holtzapple Mark T

Classifications

• F01K21/04

  using mixtures of steam and gas; Plants generating or heating steam by bringing water or steam into direct contact with hot gas ({F01K25/005, F02B47/02 take precedence; injecting water or steam into a as gas turbine plant F02C3/305}; direct-contact steam generators in general F22B) · CPC title

• F02C6/18

  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 title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title

• F01K23/10

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• F01K27/00

  Plants for converting heat or fluid energy into mechanical energy, not otherwise provided for · CPC title