Pump Startup Pressure Feedback for Soft-Fill Piping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pump systems face challenges in controlling rotation speed during startup when pipes are empty or incompletely filled, leading to pressure peaks that can stress mechanical components and require costly and time-consuming commissioning to determine suitable maximum rotation speed limits for different piping systems.
Innovation Solution
The rate of change of rotation speed is made dependent on the rate of change of measured liquid pressure, with the rate of change adjusted to be a descending function of the pressure, allowing for smoother startup and reducing the risk of pressure peaks through a frequency converter's output frequency adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump is started at maximum speed to reduce startup time, then productivity is improved, but pressure peaks occur in the piping system causing mechanical stress and potential leakages
Solution Approach 1:
The patent applies dynamics by making the pump's rotation speed adjustable and variable during startup rather than fixed at maximum speed. The control unit dynamically modifies the rotation speed based on real-time pressure measurements from the piping system, allowing the system to adapt its performance characteristics during the startup phase to balance speed and pressure control.
Solution Approach 2:
The patent implements feedback control by using a pressure sensor to continuously monitor the pressure in the piping system during startup and feeding this information back to the control unit. The control unit then adjusts the pump's rotation speed based on the measured pressure, creating a closed-loop control system that prevents pressure peaks while maintaining efficient startup.
2Reliability
If a maximum rotation speed value is limited to prevent pressure peaks, then pressure control is improved, but commissioning becomes time-consuming and costly due to required experiments and theoretical studies
Solution Approach 1:
The patent applies self-service by enabling the pump system to automatically determine its own optimal rotation speed limits during operation. The control unit uses real-time pressure feedback to dynamically adjust the rotation speed without requiring pre-programmed limits or manual commissioning experiments, allowing the system to self-optimize its performance based on actual operating conditions.
Solution Approach 2:
The patent makes the rotation speed control dynamic and adaptive rather than static and pre-determined. The system continuously adjusts the rotation speed based on real-time pressure conditions, eliminating the need for static maximum speed values that would require extensive commissioning experiments to determine for each specific piping system.
3Stability of the object's composition
If the rotation speed is PI-controlled based on pressure difference, then pressure stability is improved, but the system cannot adapt to rapidly changing counter-pressure characteristics when pipes fill with liquid
Solution Approach 1:
The patent enhances feedback control by using real-time pressure measurements to dynamically adjust the rotation speed during startup. This feedback mechanism allows the system to respond to rapidly changing pressure conditions when pipes fill with liquid, improving both stability and adaptability compared to fixed PI-control parameters.
Solution Approach 2:
The patent makes the control system dynamic by continuously adjusting the rotation speed based on real-time pressure conditions rather than using fixed PI-control parameters. This dynamic adaptation allows the system to effectively handle the rapidly changing counter-pressure characteristics that occur during the filling phase.
Data Source
AI summary
A method and arrangement for soft start up of a pump system, that includes a pump for generating a liquid flow, an electrical drive disposed to actuate the pump, and a pressure sensor disposed to measure a liquid pressure at a flow output of the pump. The rate of change of rotation speed of the pump during a start up phase is dependent on a rate of change of measured liquid pressure, wherein the rate of change of the rotation speed is a descending function of the rate of change of the measured liquid pressure.