Pump Wear Detection via Frequency Converter Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting wear in centrifugal pumps require shutdowns or additional sensor installations, making them inefficient and disruptive to pump operations.
Innovation Solution
A method using calculations from a frequency converter and characteristic curves to estimate flow rate, comparing estimated values with measured ones, providing indicators of pump wear without requiring changes to the process or additional sensors, utilizing a portable ultrasonic flow meter for accurate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If thermodynamic efficiency measurements or direct measurements of head, flow rate and shaft power consumption are used to determine pump wear, then measurement precision is improved, but the pump must be shut down and additional sensors must be permanently installed
Solution Approach 1:
The patent replaces direct mechanical measurements (head, flow rate, shaft power sensors) with electrical parameter measurements from the frequency converter. The system uses motor current, voltage, and power factor data to calculate pump performance parameters, eliminating the need for mechanical sensors and pump shutdowns.
Solution Approach 2:
The patent introduces an intermediary calculation model that uses frequency converter electrical parameters to estimate pump performance. Instead of directly measuring pump parameters, the system uses electrical power consumption data as an intermediary to infer flow rate and head, avoiding direct sensor installation on the pump.
2Measurement precision
If direct measurements of head, flow rate and shaft power consumption are used, then measurement precision is improved, but device complexity increases due to additional sensors
Solution Approach 1:
The patent makes the frequency converter multi-functional by using it not only for motor control but also for pump performance monitoring. The existing frequency converter hardware is utilized to measure electrical parameters and calculate pump performance, eliminating the need for separate measurement devices.
Solution Approach 2:
The system uses the frequency converter's own measurement capabilities to monitor pump wear. The frequency converter already measures electrical parameters for motor control, and the patent leverages these existing measurements for the additional function of pump performance monitoring without requiring external measurement systems.
3Measurement precision
If thermodynamic efficiency measurements are used to detect pump wear, then measurement precision is improved, but loss of time occurs due to pump shutdown requirements
Solution Approach 1:
The patent enables continuous pump operation during wear detection by using electrical parameter measurements from the frequency converter. The system continuously monitors motor current, voltage, and power factor to track pump performance degradation without requiring shutdowns, maintaining continuous useful action in the pumping process.
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 reliable detection of pump wear without process interruptions or additional sensor installations, effectively monitoring performance decreases by analyzing estimation errors and trends over time.
Implementation Method 1
a frequency converter that provides estimates for the pump operating point location (Q, H), shaft torque T and rotational speed n
Implementation Method 2
an external measurement device for the flow velocity v, flow rate Q, or the head H of the pump
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
A method and an arrangement for detecting wear of a pump, which pump is controlled with a frequency converter providing rotational speed and torque estimates, the characteristic curves of the pump being known. The method comprises obtaining a value representing the operating point of the pump by measuring the flow (Qact) or the head (Hact) produced by the pump, estimating the operating point of the pump by using a calculation based on the characteristic curves of the pump and the estimated rotational speed (nest) of the pump and the estimated torque (Test) of the pump, calculating an estimation error from the value representing the operating point and from the estimated operating point, repeating the above steps during the use of the pump, and detecting the wear of the pump from the amplitude of the estimation error.