Pump Flow Rate Estimation Using Pressure and Temperature
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating flow rates in pumps, especially for multiphase and compressible fluids, face challenges with varying viscosity, requiring extensive calibration and struggling with accuracy, particularly in viscous flows like heavy oils, and are dependent on fluid viscosity measurements which are difficult to model or measure in real-time.
Innovation Solution
A method that calculates the estimated flow rate using measurements of pressure, temperature, and electrical power, determining fluid density and specific heat capacity or enthalpy, allowing for accurate estimation even with varying viscosity, without the need for extensive calibration, and can account for compressibility using cross-sectional area and historical data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing soft sensor methods are used to estimate flow rate, then flow rate can be determined using pump parameters and electrical power measurements, but accuracy deteriorates when fluid viscosity varies or for multiphase flows
Solution Approach 1:
The invention changes the parameters used for flow rate estimation from traditional pump performance curves (which assume constant fluid properties) to a method that explicitly incorporates measured fluid temperature, density, and viscosity parameters. By continuously monitoring these fluid parameters and adjusting the estimation algorithm accordingly, the system maintains accuracy across varying viscosity conditions and multiphase flows that previously caused deterioration in measurement precision.
2Measurement precision
If extensive calibration is performed to improve accuracy for varying viscosity fluids, then flow rate estimation accuracy improves, but device complexity and calibration time increase
Solution Approach 1:
The system performs self-calibration by automatically measuring fluid temperature, density, and viscosity parameters during operation and using these measurements to adjust the flow rate estimation algorithm in real-time. This eliminates the need for extensive manual calibration procedures while maintaining high accuracy across varying fluid conditions. The system serves itself by continuously adapting to changing fluid properties without external intervention.
Solution Approach 2:
The invention performs preliminary measurements of fluid temperature, density, and viscosity before conducting the flow rate estimation. By obtaining these fluid parameters in advance and using them to pre-adjust the estimation algorithm, the system prepares the calculation process to handle varying viscosity conditions proactively, thereby improving accuracy without requiring complex post-calibration procedures.
3Measurement precision
If real-time viscosity measurements are implemented to improve flow rate accuracy, then measurement precision improves, but difficulty of detecting and measuring increases
Solution Approach 1:
Instead of directly measuring viscosity, which is difficult and expensive, the invention uses temperature and density measurements as intermediary parameters. These easier-to-measure quantities serve as proxies that correlate with viscosity changes. By measuring temperature and density (which are straightforward to obtain) and using established relationships between these parameters and viscosity, the system indirectly obtains viscosity information without the complexity of direct viscosity measurement.
Solution Approach 2:
The invention replaces complex mechanical viscosity measurement systems with a computational approach. Instead of using mechanical viscometers or rheometers that require direct fluid sampling and complex mechanical measurements, the system uses electrical sensors to measure temperature and density, then employs computational algorithms to derive viscosity information. This substitution of mechanical measurement systems with electrical sensing and computational processing significantly reduces measurement difficulty while maintaining accuracy.
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 accurate estimation of flow rates in pumps handling multiphase fluids with varying viscosity, such as heavy oils, without requiring instantaneous measurements or extensive calibration, providing improved accuracy and adaptability to changing pump conditions.
Implementation Method 1
the electrical power supplied to the pump
Implementation Method 2
the pressure and temperature of fluid at the intake to the pump, the pressure and temperature of the fluid at the discharge from the pump
Implementation Method 3
the pressure and temperature of fluid at the intake to the pump, the pressure and temperature of the fluid at the discharge from the pump
Data Source
AI summary
A method for determining an estimated flow rate of fluid flow in a pump comprises: obtaining measurements of the pressure and temperature of fluid at the intake to the pump, the pressure and temperature of the fluid at the discharge from the pump, and the electrical power supplied to the pump; determining values representing either the density of the fluid and the specific heat capacity of the fluid, or the specific fluid enthalpy based on measurements and/or historical data; and calculating an estimated efficiency of the pump and an estimated flow rate of the fluid based on the measured electrical power, the measured temperatures, the measured pressures, the determined value for density and the determined value for specific heat capacity or the determined value for specific fluid enthalpy.