PTFE Bellows Compensator for High-Temperature Submersible Pumps

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Solution Overview

Problem

Conventional compensators used in submersible geothermal pump systems are limited by their temperature resistance and size, making them inadequate for high-temperature and high-pressure environments, where they are required to manage thermal expansion and pressure balancing effectively.

Innovation Solution

A modular compensator assembly utilizing a longitudinally extending elastomeric compensator made from polytetrafluoroethylene (PTFE) with a bellows-like structure, capable of operating up to 160°C, which includes a conveying tube for fluid communication and a metal housing for securing and guiding the compensator, allowing for thermal expansion and contraction while maintaining pressure balance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional rubber compensators are used, then the compensator provides thermal expansion accommodation and pressure balancing, but the compensator fails in high temperature environments exceeding 110°C

Engineering Contradiction:
Improveoperating temperatureVSAvoidcompensator reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent changes the material parameter from conventional rubber to PTFE (polytetrafluoroethylene), which has a significantly higher temperature resistance capability. This material substitution allows the compensator to operate reliably in high temperature environments up to 160°C while maintaining its functional properties for thermal expansion accommodation and pressure balancing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs PTFE, an advanced fluoropolymer material with superior thermal and chemical resistance properties compared to conventional rubber. This composite material approach enables the compensator to withstand high temperature geothermal environments while maintaining structural integrity and functional performance.

Inventive Principle:
Principle #40Composite materials

2Length of moving object

If conventional single-size compensators are used, then the compensator is easy to manufacture, but the compensator is too small for high power submersible pump applications

Engineering Contradiction:
Improvecompensator lengthVSAvoidmanufacturing complexity
Core Design Contradiction:
Length of moving objectVSEase of manufacture

Solution Approach 1:

The patent divides the compensator into multiple modular sections that can be connected in series to achieve the required total length for high power applications. Each module contains standardized components (crests, grooves, conveying tubes) that can be manufactured using consistent processes, then assembled to create custom-length compensators without significantly increasing manufacturing complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces modularity as an additional design dimension, allowing the compensator system to scale in length through modular repetition rather than requiring custom manufacturing for each size. This modular architecture enables high power applications to use extended compensator assemblies while maintaining the ease of manufacture benefits through standardized module production.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Volume of stationary object

If the compensator is made larger for high power applications, then the compensator can accommodate high power motors, but the compensator requires modular combinations of multiple compensators

Engineering Contradiction:
Improvecompensator volumeVSAvoidcompensator structure
Core Design Contradiction:
Volume of stationary objectVSDevice complexity

Solution Approach 1:

The patent segments the large-volume compensator requirement into multiple smaller modular units connected in series. Each module maintains a manageable volume and standardized structure, while the modular combination achieves the total volume needed for high power motor applications. This segmentation reduces individual component complexity while meeting overall system requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs each modular compensator unit with universal connection interfaces and standardized features (crests, grooves, conveying tubes) that can be replicated and combined. This universality allows multiple modules to be assembled into larger volume configurations without increasing structural complexity, as each module performs the same functions and connects through standardized mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Temperature

If the compensator material is changed to PTFE for high temperature operation, then the compensator can operate up to 160°C, but the compensator material must be elastomeric to maintain flexibility

Engineering Contradiction:
Improvetemperature resistanceVSAvoidmaterial flexibility
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent selects PTFE (polytetrafluoroethylene), an advanced fluoropolymer material that combines high temperature resistance (operable up to 160°C) with elastomeric flexibility. This composite material approach maintains the necessary mechanical properties for compensator function while enabling operation in high temperature geothermal environments, resolving the conflict between temperature resistance and material flexibility.

Inventive Principle:
Principle #40Composite materials

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

The solution provides reliable operation and extended lifespan of submersible motors by effectively managing thermal expansion and pressure balancing in high-temperature and high-pressure environments, preventing over-pressurization and maintaining a low pressure differential, thus ensuring efficient heat transfer and mechanical seal integrity.

Implementation Method 1

the compensator comprises a degree of elasticity sufficient for a width of at least one of the grooves to expand and contract with thermal expansion and contraction, respectively, of the motor cooling liquid contained therein

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

The compensator includes a series of alternating crests and grooves such that the compensator generally defines a bellows-like (or accordion-like) structure extending along its longitudinal axis

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

The cooling liquid typically absorbs the heat from the motor and transfers it to the surrounding liquid in the well

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 4

The cooling liquid typically absorbs the heat from the motor and transfers it to the surrounding liquid in the well

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 5

the compensator performs several functions that contribute to the reliable operation of the motor, including providing for thermal expansion of the motor cooling liquid during motor operation, and balancing motor interior and exterior pressures

Methodology Applied
Scientific EffectPressure balancing:

Data Source

PatentEP2501897B1Compensator assembly for submersible pump system
Publication Date: 2014.06.25 FLOWSERVE MANAGEMENT COMPANY
  • EP2501897B1 patent drawingFigure 1
  • EP2501897B1 patent drawingFigure 2A
  • EP2501897B1 patent drawingFigure 2B

AI summary

A submersible pump system with a pump, motor and compensator assembly. In one embodiment, the compensator assembly is made up of multiple elastomeric compensators and a housing. The elastomeric compensators, which are made up of an engaging end, a floating end and a series of alternating crests and grooves, may contain motor cooling liquid. The crests and grooves extend along the compensator's longitudinal axis. The compensators possess a degree of elasticity sufficient for a width of at least one of the respective grooves to expand and contract along with the motor cooling liquid. The crests slide along an interior wall of the housing, while the floating end moves within the housing in cooperation with expansion and contraction of the width of at least one of the grooves.