Smart Fluid Unloader for Compressor Suction Valve Control

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Solution Overview

Problem

Hydraulically-actuated infinite step controllers (ISCs) in reciprocating compressors increase complexity and operating costs due to their reliance on complex hydraulic systems, necessitating a more reliable and precise system for controlling suction valve positions.

Innovation Solution

An unloader assembly utilizing smart fluids, such as electrorheological or magnetorheological fluids, activated by electrical coils to change viscosity, coupled with an actuating rod and plunger plate mechanism, which engages and biases the suction valve elements to control valve position without hydraulic complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hydraulically-actuated infinite step controllers are used to control suction valve positions, then the control precision and reliability are improved, but the device complexity and operating costs increase

Engineering Contradiction:
Improvesuction valve position control precisionVSAvoidhydraulic system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the hydraulic actuation system with a direct mechanical actuation system. The infinite step controller uses a mechanical rack and pinion mechanism driven by a rotary actuator to control the suction valve position, eliminating the need for complex hydraulic components while maintaining precise control capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the hydraulic system from the infinite step controller design. By taking out the hydraulic actuation mechanism, the patent simplifies the overall system while retaining the essential function of precise suction valve position control through a simpler mechanical system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If hydraulically-actuated infinite step controllers are used to control suction valve positions, then the control precision and reliability are improved, but the operating and maintenance costs increase

Engineering Contradiction:
Improvesuction valve position control precisionVSAvoidoperating and maintenance costs
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the hydraulic actuation system with a direct mechanical actuation system. The infinite step controller uses a mechanical rack and pinion mechanism driven by a rotary actuator to control the suction valve position, eliminating the need for complex hydraulic components while maintaining precise control capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs simpler mechanical components that are more cost-effective and easier to maintain compared to hydraulic systems. The mechanical actuation system uses standard, readily available components with lower operating and maintenance costs.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If a simple mechanical actuation system is used instead of hydraulic systems, then the device complexity and operating costs are reduced, but the speed and precision of valve position control may be compromised

Engineering Contradiction:
Improveactuation system complexityVSAvoidvalve position response speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent incorporates a rapidly responding rotary actuator that can quickly adjust the suction valve position. The mechanical rack and pinion mechanism provides direct, responsive actuation without the lag associated with hydraulic systems, enabling fast and precise valve position changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent divides the actuation system into discrete, independently controllable segments. The rotary actuator can be precisely controlled to achieve incremental position adjustments, allowing for both rapid response and fine position control through segmented motion control.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables rapid and precise control of suction valve positions, reducing operating and maintenance costs by eliminating the need for complex hydraulic systems while maintaining reliable operation.

Implementation Method 1

a first reservoir containing a smart fluid including electrorheological fluid, magnetorheological fluid, or both. The apparatus may also include one or more coils disposed proximal the smart fluid and coupled to a source of electrical current, such that when an electrical current is provided to the one or more coils, the smart fluid changes from a relatively low-viscosity fluid to a relatively high-viscosity gel

Methodology Applied
Scientific EffectElectrorheological effect: Electrorheological Effect

Implementation Method 2

a first reservoir containing a smart fluid including electrorheological fluid, magnetorheological fluid, or both. The apparatus may also include one or more coils disposed proximal the smart fluid and coupled to a source of electrical current, such that when an electrical current is provided to the one or more coils, the smart fluid changes from a relatively low-viscosity fluid to a relatively high-viscosity gel

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Data Source

PatentEP2683950B1Electronic infinite step controller actuator
Publication Date: 2016.07.20 DRESSER RAND CO
  • EP2683950B1 patent drawingFigure 1
  • EP2683950B1 patent drawingFigure 2
  • EP2683950B1 patent drawingFigure 3

AI summary

An unloader assembly and method for unloading a compressor, with the unloader assembly including one or more fingers configured to engage one or more valve elements of a suction valve of the compressor. The unloader assembly also includes a biasing member coupled to the one or more fingers and configured to bias the one or more fingers downward such that the one or more fingers follow the one or more valve elements, and an actuating rod coupled to the one or more fingers and extending longitudinally therefrom. The unloader assembly further includes a first reservoir containing a smart fluid and adapted to receive the actuating rod, and a coil disposed at least one of proximal to and within the first reservoir, with the coil being configured to produce a field when an electrical current is supplied to the coil, to change one or more viscoelastic properties of the smart fluid.