Compressor Rotational Rate Control for Oil Separation

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Solution Overview

Problem

Compressors struggle to maintain reliable operation over time due to insufficient rotational rates, leading to inefficient oil separation and excessive oil content in pressurized air, especially when operating at lower performance demands.

Innovation Solution

A method to control the rotational rate of compressors by determining a target rotational rate and adjusting lower and upper limits based on monitored performance demands, ensuring the mean rotational rate remains at least as high as a minimum value to prevent oil separation issues and reduce wear from frequent high-low rate alternations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the compressor operates at lower rotational rates to reduce energy consumption, then energy efficiency improves, but oil separation becomes insufficient and excessive oil content appears in pressurized air

Engineering Contradiction:
Improveenergy consumptionVSAvoidoil separation performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic adjustment of the lower rotational rate limit based on operational duration. The control unit monitors how long the compressor has been operating and dynamically raises the minimum rotational rate threshold as operation time increases, ensuring oil separation performance is maintained during extended operation while allowing lower rates during brief operation periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the rotational rate parameter dynamically based on operational duration. The lower rotational rate limit is not fixed but is adjusted as a function of how long the compressor has been running, allowing the system to adapt the rotational rate parameter to maintain reliable oil separation performance over time.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the compressor frequently alternates between high and low rotational rates to match varying performance demands, then adaptability improves, but wear increases due to frequent alternations

Engineering Contradiction:
Improveperformance demand adaptationVSAvoidcomponent service life
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The patent implements dynamic threshold adjustment where the lower rotational rate limit increases with operational duration. This dynamic behavior allows the compressor to adapt to varying demands while automatically reducing the frequency of alternations between high and low rotational rates, as the rising threshold discourages frequent drops to low rates during extended operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit continuously monitors operational duration and uses this feedback to adjust the lower rotational rate limit. This feedback mechanism creates a self-regulating system that adapts the rotational rate thresholds based on accumulated operation time, thereby reducing excessive alternations and extending component service life.

Inventive Principle:
Principle #23Feedback

3Productivity

If the lower rotational rate limit is kept low to allow efficient operation at varying demands, then operational efficiency improves, but the mean rotational rate drops below minimum values causing unreliable compressor function

Engineering Contradiction:
Improveoperational efficiencyVSAvoidcompressor function reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent makes the lower rotational rate limit a dynamic parameter that increases with operational duration. This allows the system to maintain high operational efficiency during brief operation periods with low thresholds, while automatically raising the threshold during extended operation to ensure the mean rotational rate remains above minimum values for reliable compressor function.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the lower rotational rate limit parameter based on operational duration to balance productivity and reliability. By adjusting this parameter dynamically, the system achieves high operational efficiency when needed while ensuring the mean rotational rate stays above critical minimum values for reliable compressor operation over time.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10815996B2Compressor and method for controlling the rotational speed thereof
Publication Date: 2020.10.27 GARDNER DENVER DEUTLAND

AI summary

The present invention relates primarily to a method for controlling the rotational rate of a compressor, which controls, in particular, the rotational rate of a rotating compression element of the compressor. The invention furthermore relates to a compressor, e.g. a compressor for generating pressurized air. The compressor is to be operated at a rotational rate, when in operation, with a mean value that is at least as high as a minimum mean value, in order to ensure the functionality of the compressor. According to the method, a temporally variable target rotational rate of the compressor that is necessary for obtaining a temporally variable output performance from a compressor is determined. In accordance with the invention, a lower rotational rate limit is raised if the temporal mean of the variable target rotational rate is lower than the minimal mean value for the rotational rate of the compressor.