INDIRECTLY HEATED GAS TURBINE CONTROL SYSTEM

• US 20050138930A1
• Filed: 04/19/2004
• Published: 06/30/2005
• Est. Priority Date: 07/03/2002
• Status: Active Grant

• Current Assignee: Richard W. Foster-Pegg
• Original Assignee: Richard W. Foster-Pegg
• Inventors: Foster-Pegg, Richard W.
• Granted Patent: US 6,938,421 B2
• Time in Patent Office: Days
• US Class Current: 60/682
• CPC Class Codes: F02C 1/04 the working fluid being heated indirectly in a fluidised-bed combustor F02C3/205
• CPC Class Codes: F16K 17/1626 with additional cutting means
• CPC Class Codes: F16K 17/403 with a fracturing valve member
• CPC Class Codes: Y10T 137/1692 Rupture disc
• CPC Class Codes: Y10T 137/1767 Movable knife or cutter

Abstract

A system for the control of an indirectly heated gas turbine comprising a primary system of controlling the temperature of heated compressed gas entering the expander, and an independent secondary system which includes a safety valve for instantaneous release of heated compressed gas to the atmosphere. The primary system controls system gas temperature and power output by modulating a flow of unheated compressed gas which bypasses the heat exchanger and mixes with the heated gas leaving the heat exchanger to produce a lower temperature gas entering the expander. The secondary system provides a backup means of overspeed prevention, and includes a safety valve to instantly discharge to the atmosphere hot compressed gas upstream of the expander by being responsive to the speed of the turbine. The safety valve includes a frangible membrane clamped between parallel flanges within the ducting, and further includes a dagger assembly for rupturing the membrane.

Claims

1. A system for controlling the power output and safety of an indirect heated gas turbine, the system comprising:

a primary control system and, a secondary control system comprising a safety valve, the secondary control system being completely separate from and independent of the primary control system, said primary control system comprising gas temperature regulation means for regulating the gas temperature entering the expander of a turbine.

2. A system for controlling the power output and safety of an indirectly heated gas turbine,

the indirectly heated gas turbine comprising a turbine wherein inlet gas is compressed within a compressor, and then passes through first ducting means to an indirect heat exchanger where it is indirectly heated, and then passes through second ducting means to an expander where it is expanded,

the system for controlling the power output of an indirectly heated gas turbine comprising a primary control system and a secondary control system, said secondary control system being completely separate from and independent of said primary control system and functioning as a backup system to said primary control system, said secondary control system operating only when said primary control system malfunctions, wherein

said primary control system comprising gas temperature regulation means for regulating the gas temperature entering the expander of the turbine, and

said secondary control system comprising a safety valve.

3. The system for controlling the power output of an indirectly heated gas turbine of claim 2 wherein said gas temperature regulation means comprises an indirect heat exchanger bypass means, said indirect heat exchanger bypass means comprising a modulation of a flow of unheated compressed gas from said compressor which bypasses the indirect heat exchanger and mixes with the heated gas leaving the indirect heat exchanger to produce a mixed gas of selected temperature entering the expander.

4. The system for controlling the power output of an indirectly heated gas turbine of claim 3 wherein said gas temperature regulation means comprises a blocker valve positioned within the outlet of the indirect heat exchanger, said blocker valve allowing the adjustment of gas flow through the indirect heat exchanger such that when said blocker valve is closed, gas flow is diverted from the indirect heat exchanger and into the indirect heat exchanger bypass means so as to reduce the temperature of the gas entering the expander thus obtaining a larger and faster reduction in power than can be produced by said indirect heat exchanger bypass means alone.

5. The system for controlling the power output of an indirectly heated gas turbine of claim 4 wherein the combined effect of said indirect heat exchanger bypass means and said blocker valve reduces the gas flow through the gas heater to approximately one-third of the compressor gas flow, such that two-thirds of the gas flow will bypass the indirect heat exchanger reducing the temperature of the gas entering the expander such that the power produced by the expander is less than is required to drive the compressor resulting in a negative net power production and slowing of turbine speed.

6. The system for controlling the power output of an indirectly heated gas turbine of claim 2 wherein said safety valve is positioned within said system such that it lies between said indirect heat exchanger and said expander, said safety valve comprising a means to instantaneously discharge the hot compressed gas from the system.

7. The system for controlling the power output of an indirectly heated gas turbine of claim 6 wherein said safety valve comprises a rupture disk, said rupture disk being located in and fully obstructing an offtake of said second ducting means between the indirect heat exchanger and the expander, said rupture disk capable of being selectively and instantaneously breached by rupture means positioned adjacent to said rupture disk.

8. The system for controlling the power output of an indirectly heated gas turbine of claim 7 wherein said rupture means comprises an activation means, said activation means requiring compressed gas pressure from the gas flow from said compressor for activation of said rupture means such that inadvertent activation of said rupture means when said indirectly heated gas turbine slows and stops is prevented.

9. The system for controlling the power output of an indirectly heated gas turbine of claim 8 wherein said rupture means further comprises a dagger that is capable of being selectively and instantaneously projected through said rupture disk.

10-21. -21. (canceled)

22. A gas turbine and control system comprising:

a. a gas compressor having a housing;

b. a heating system for heating compressed gas;

c. a gas expander for receiving and expanding heated compressed gas;

d. a compressed gas by-pass system and control therefore;

e. a drive shaft common to the gas compressor and the gas turbine, said drive shaft extending externally to the gas compressor housing;

f. a gas turbine safety valve system having a ruptureable membrane;

g. at least one rotational speed detector mounted on the drive shaft;

h. a control system for controlling and monitoring the rotational speed detector;

i. a central control system for controlling and monitoring the integrated operation of the;

i. the gas compressor,

ii. the heating system for the compressed gas,

iii. the gas turbine,

iv. the compressed gas by-pass system,

v. the drive shaft,

vi. the gas turbine safety valve system,

vii. any rotational speed detectors present in the system,

viii. any auxiliary equipment for the efficient operation of the gas turbine and control,

ix. driven equipment,

wherein, the gas compressor is configured with gas transfer means to draw gas therein and after compression of the gas, transfer the gas to the heating system for the gas;

the heating system is configured to heat the compressed gas and is configured with gas transfer means to transfer the heated, compressed gas to the gas turbine gas expander, and the gas turbine is configured with gas transfer means for exhausting expanded gas externally to the gas turbine and control system,

wherein, the compressed gas by-pass system and control is configured with gas transfer means such that the compressed gas by-pass system receives unheated compressed gas directly from the gas compressor when in an active mode, whereby the heated compressed gas from the heating system and unheated compressed gas from the by pass system are conducted by a gas transfer means to the expander of the gas turbine, and then exhausted exterior of the gas turbine, and wherein power output of said gas turbine is modulated by modulation of flow of gas within said compressed gas by pass system,

wherein, the gas turbine safety valve system is configured with gas transfer means such that the safety valve receives heated compressed gas from the heating system, and upon rupturing of the ruptureable membrane in the gas turbine safety valve system, exhausting the heated compressed gas to the externally of the gas turbine and thereby essentially preventing the flow of heated compressed gas to the expander of the gas turbine.