US4976588A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compressor control system to improve turndown and reduce incidents of surging
Assignee: Elliott Turbomachinery Co Inc
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Filing: 1990-05-31
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Granted: 1990-12-11
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Expires: 2010-05-31
Abstract
Abstract A method and apparatus for regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir are disclosed. In accordance with the method, an unload valve in an unload conduit connected to the discharge conduit is initially fully closed and an inlet valve in the intake conduit is initially fully opened. Then the inlet valve is closed by an amount necessary to maintain the discharge pressure at a design pressure level and at a gas flow rate between the design flow level and a minimum flow level. When the gas flow rate drops below the minimum flow level, the inlet valve is maintained in its last position and the unload valve is opened by an amount necessary to maintain the discharge pressure below a first pressure level set higher than the design pressure level. If the unload valve remains open beyond a position set point for longer than a first predetermined period of time, the unload valve is fully opened and the inlet valve is fully closed. Then if the system pressure drops below a second pressure level lower than the design pressure, the control steps discussed above are repeated.
Inventors
- 👤 Bruce G. Heckel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:05
CPC Classifications
F; F04; F04D; F04D27/00; F04D27/02; F04D27/0284
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
277 words
A method of regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir, an inlet valve in said intake conduit, an unload valve in said unload conduit, means for detecting the discharge pressure of said compressor, means for detecting the flow rate of gas from said compressor and means for detecting the system pressure in said reservoir, said method comprising the steps of: (a) initially fully closing the unload valve and fully opening the inlet valve; (b) closing the inlet valve by an amount necessary to maintain the discharge pressure at a constant design pressure level and to maintain the gas flow rate at a constant design flow level; (c) detecting when said discharge pressure reaches a first pressure level set higher than said design pressure level; (d) thereafter maintaining the inlet valve in its last position and opening the unload valve by an amount necessary to maintain the discharge pressure below said first pressure level as the gas flow rate drops below said design flow level; (e) monitoring the position of the unload valve and measuring the period of time that the unload valve remains open beyond a predetermined position set point; (f) fully opening the unload valve and fully closing the inlet valve if the unload valve remains open beyond the position set point for longer than a first predetermined period of time; (g) monitoring the system pressure and comparing said system pressure with a second pressure level lower than said design pressure level; and (h) repeating steps a-g if the system pressure drops below said second pressure level.
Claim 2
Independent Claim
277 words
A method of regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir, an inlet valve in said intake conduit, an unload valve in said unload conduit, means for detecting the discharge pressure of said compressor, means for detecting the flow rate of gas from said compressor and means for detecting the system pressure in said reservoir, said method comprising the steps of: (a) initially fully closing the unload valve and fully opening the inlet valve; (b) closing the inlet valve by an amount necessary to maintain the discharge pressure at a constant design pressure level and to maintain the gas flow rate at a constant design flow level; (c) detecting when said discharge pressure reaches a first pressure level set higher than said design pressure level; (d) thereafter maintaining the inlet valve in its last position and opening the unload valve by an amount necessary to maintain the discharge pressure below said first pressure level as the gas flow rate drops below said design flow level; (e) monitoring the position of the unload valve and measuring the period of time that the unload valve remains open beyond a predetermined position set point; (f) fully opening the unload valve and fully closing the inlet valve if the unload valve remains open beyond the position set point for longer than a first predetermined period of time; (g) monitoring the system pressure and comparing said system pressure with a second pressure level lower than said design pressure level; and (h) repeating steps a-g if the system pressure drops below said second pressure level.
Claim 3
Dependent Claim
53 words
The method of claim 1 further including between steps (g) and (h) the step of monitoring the period of time that the unload valve remains fully open in step (f) and stopping further rotation of said compressor if the unload valve remains fully open for longer than a second predetermined period of time.
Claim 4
Dependent Claim
34 words
The method of claim 1 wherein said compressor system includes a motor driving the compressor and a current transmitter detecting current in said motor, with said current transmitter forming said fluid flow detecting means.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein said discharge pressure detecting means is a discharge pressure transmitter connected to said discharge conduit.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein said system pressure detecting means is a system pressure transmitter connected to said reservoir.
Claim 7
Independent Claim
295 words
An apparatus for regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir, an inlet valve in said intake conduit, an unload conduit connected to said discharge conduit, an unload valve in said unload conduit, means for detecting the discharge pressure of said compressor, means for detecting the flow rate of gas from said compressor and means for detecting the system pressure in said reservoir, said apparatus comprising: (a) means for initially fully closing the unload valve and fully opening the inlet valve; (b) means for closing the inlet valve by an amount necessary to maintain the discharge pressure at a constant design pressure level and to maintain the gas flow rate at a constant design flow level; (c) means for detecting when said discharge pressure reaches a first pressure level set higher than said design pressure level; (d) means for maintaining the inlet valve in its last position and opening the unload valve by an amount necessary to maintain the discharge pressure below said first pressure level as the gas flow rate drops below said design flow level; (e) means for monitoring the position of the unload valve and measuring the period of time that the unload valve remains open beyond a predetermined position set point; (f) means for fully opening the unload valve and fully closing the inlet valve if the unload valve remains open beyond the position set point for longer than a first predetermined period of time; (g) means for monitoring the system pressure and comparing said system pressure with a second pressure level lower than said design pressure level; and (h) means for detecting if the system pressure drops below said second pressure level.
Claim 8
Independent Claim
295 words
An apparatus for regulating the operation of a compressor system including a compressor moving a gas from an intake conduit through a discharge conduit to a gas storage reservoir, an inlet valve in said intake conduit, an unload conduit connected to said discharge conduit, an unload valve in said unload conduit, means for detecting the discharge pressure of said compressor, means for detecting the flow rate of gas from said compressor and means for detecting the system pressure in said reservoir, said apparatus comprising: (a) means for initially fully closing the unload valve and fully opening the inlet valve; (b) means for closing the inlet valve by an amount necessary to maintain the discharge pressure at a constant design pressure level and to maintain the gas flow rate at a constant design flow level; (c) means for detecting when said discharge pressure reaches a first pressure level set higher than said design pressure level; (d) means for maintaining the inlet valve in its last position and opening the unload valve by an amount necessary to maintain the discharge pressure below said first pressure level as the gas flow rate drops below said design flow level; (e) means for monitoring the position of the unload valve and measuring the period of time that the unload valve remains open beyond a predetermined position set point; (f) means for fully opening the unload valve and fully closing the inlet valve if the unload valve remains open beyond the position set point for longer than a first predetermined period of time; (g) means for monitoring the system pressure and comparing said system pressure with a second pressure level lower than said design pressure level; and (h) means for detecting if the system pressure drops below said second pressure level.
Claim 9
Dependent Claim
44 words
The apparatus of claim 6 further including means for monitoring the period of time that the unload valve remains fully open and stopping further rotation of said compressor if the unload valve remains fully open for longer than a second predetermined period of time.
Claim 10
Dependent Claim
34 words
The apparatus of claim 6 wherein said compressor system includes a motor driving the compressor and a current transmitter detecting current in said motor, with said current transmitter forming said fluid flow detecting means.
Claim 11
Dependent Claim
21 words
The apparatus of claim 6 wherein said discharge pressure detecting means is a discharge pressure transmitter connected to said discharge conduit.
Claim 12
Dependent Claim
20 words
The apparatus of claim 6 wherein said system pressure detecting means is a system pressure transmitter connected to said reservoir.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |