Flow Velocity Estimation Using Pressure Differential and Loss Coefficients
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Solution Overview
Problem
Existing methods for detecting water leaks in water pipes require closing the solenoid valve for a predetermined period, limiting the detection time and necessitating a continuous monitoring solution for flow velocity without pipe closure.
Innovation Solution
A flow velocity estimation apparatus comprising a solenoid valve and a pressure sensor, with a control unit that calculates flow velocity using pre-obtained loss coefficients and pressure differences, allowing continuous estimation without closing the water pipe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solenoid valve is closed for a predetermined period to detect water leaks, then leak detection capability is improved, but the detection period is limited and water flow is disrupted
Solution Approach 1:
The loss coefficients (ζv for solenoid valve, ζp for upstream pipe) are obtained in advance through calibration processes. This preliminary characterization allows the system to calculate flow velocity continuously using real-time pressure measurements without needing to close the valve for detection, thereby resolving the contradiction between reliable leak detection and continuous operation
Solution Approach 2:
The invention replaces the mechanical approach of closing the solenoid valve to detect leaks with a calculation-based method using pressure sensor data and pre-obtained loss coefficients. The control unit continuously estimates flow velocity by processing pressure differential signals, eliminating the need for mechanical valve closure and enabling uninterrupted water flow during detection
2Measurement precision
If multiple pressure gauges or additional devices like flow meters and pumps are used to measure flow velocity, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The pressure sensor serves multiple functions: it measures both the upstream pressure (P0 when valve is closed) and the downstream pressure (P1 when valve is open) to calculate flow velocity. The same sensor is used for both calibration and continuous monitoring operations, eliminating the need for separate measurement devices and reducing overall system complexity while maintaining measurement precision
Solution Approach 2:
The system uses the existing solenoid valve infrastructure and a single pressure sensor to achieve flow velocity measurement. The control unit processes the pressure differential data through calculations using pre-stored loss coefficients, allowing the system to self-determine flow velocity without requiring additional specialized measurement devices
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 continuous estimation of flow velocity in water pipes during active water supply, facilitating early leak detection without disrupting the water flow, thereby preventing waste and damage.
Implementation Method 1
a pressure sensor disposed downstream from the solenoid valve in the water pipe and configured to detect a pressure of the water
Implementation Method 2
The relationship between the flow velocity v of water and a pressure loss ΔP is represented by the following equation by using a loss coefficient ζ and a density of water ρ. ΔP=(ζρv2)/2
Data Source
AI summary
An apparatus includes a solenoid valve and a pressure sensor disposed in a water pipe in this order from an upstream end, and a control unit controlling open/close of the solenoid valve and receives a sensor signal outputted from the pressure sensor. The controller obtains a difference between a water pressure measured by the pressure sensor when it is determined that the decreased degree of opening is increased, and a water pressure measured by the pressure sensor when a flow velocity is zero, and calculates a loss coefficient of an upstream water pipe located upstream from the solenoid valve based on the pressure difference and a flow velocity calculated based on a loss coefficient of the solenoid valve. The controller estimates a flow velocity of the water currently flowing in the water pipe based on the loss coefficient and the difference between water pressures of the last and present measurements.