Parallel Pump Control Using Self-Sensed Flow and Head
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Solution Overview
Problem
Existing HVAC systems with multiple pumps do not efficiently manage energy consumption due to methods that only consider electrical power or speed, failing to account for system changes when additional pumps are activated, leading to inefficiencies.
Innovation Solution
A controller system that communicates with multiple pump assemblies, using variable frequency drives to adjust pump speed based on flow, head, and power estimates to optimize energy use by switching pumps on or off dynamically, employing PID control and linear regression to determine the most efficient switching points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If pumps are switched on or off based on speed thresholds or wire-to-liquid efficiency, then pump operation can be controlled, but energy efficiency is not optimized because system changes when additional pumps are started are not accounted for
Solution Approach 1:
The controller continuously monitors system parameters (flow, head, power consumption) and uses this feedback to dynamically adjust pump operation. The system calculates wire-to-head efficiency in real-time and uses this feedback to determine optimal pump switching points, ensuring energy efficiency while adapting to changing system conditions.
Solution Approach 2:
The system uses its own operational data (power consumption, flow rates, head measurements) to make autonomous decisions about pump switching. The controller self-regulates by comparing actual performance against efficiency targets without requiring external intervention or complex external sensing infrastructure.
2Adaptability or versatility
If multiple pumps are operated in parallel to meet varying flow demands, then system adaptability improves, but determining the optimal number of pumps to operate becomes complex
Solution Approach 1:
The system dynamically changes operational parameters (number of active pumps, pump speeds) based on real-time calculations of wire-to-head efficiency. By continuously monitoring flow, head, and power consumption, the controller adjusts pump configuration to maintain optimal efficiency across varying demand conditions.
Solution Approach 2:
The pump control system transitions from static speed-based switching to dynamic efficiency-based switching. The controller continuously evaluates system conditions and adapts pump operation in real-time, allowing the system to dynamically respond to changing flow demands while optimizing energy consumption.
3Use of energy by moving object
If wire-to-liquid efficiency is used to control pump switching, then energy consumption is considered, but system changes when pumps are started are not taken into account
Solution Approach 1:
The controller uses real-time feedback from flow meters, pressure sensors, and power monitors to continuously update wire-to-head efficiency calculations. This feedback loop ensures that pump switching decisions account for actual system conditions and the impact of adding or removing pumps from operation.
Solution Approach 2:
The system performs preliminary calculations of expected system changes before executing pump switching. By predicting how wire-to-head efficiency will change when pumps are added or removed, the controller can make informed decisions that account for system dynamics and avoid suboptimal switching points.
Data Source
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AI summary
A hydraulic pumping system for pumping a flow of aqueous liquid, for HVAC and potable water systems, through a plurality of hydraulic pump assemblies and mating branching feeder pipes extending between a main inlet pipe and a main outlet pipe for outputting the total flow of water, each of said pump assemblies in operative association with a mating feeder pipe to control aqueous liquid flow through said associated feeder pipe, wherein each of the hydraulic pump assemblies comprises an electric motor, mechanically coupled to a centrifugal pump and a variable frequency drive (VFD) electrically coupled to the motor. A controller is electrically coupled via a communication channel to the VFD of each of the hydraulic pump assemblies, the controller comprising a programmable device programmed to control the speed of each of the motors via the connected VFD. The controller receives data from each of the VFDs, said data comprising the amount of electrical power consumed by the VFD, the speed of the associated motor, an estimation of aqueous liquid flow, and an estimation of head, and calculates the total aqueous liquid flow through the plurality of pump assemblies, and the total system head, so that the controller can vary the speed of each VFD to adjust the total system with respect to the desired system head.