Remote Valve Calibration Using Sparse Surface-Fit Flow Data
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Solution Overview
Problem
Current fluid flow measurement devices are expensive and have limited turndown ratios, making them ineffective for accurately measuring low fluid flows, particularly in HVAC systems, leading to energy inefficiency and discomfort due to the inability to regulate air flow accurately.
Innovation Solution
A fluid flow measurement and control system utilizing a multi-stage damper with a variable orifice plate and actuator assembly, which includes a central opening and an inner assembly with nested elements, allowing for precise control of fluid flow through a wide range of velocities and enabling a high turndown ratio, thereby improving measurement accuracy and energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional fluid flow measurement devices are used, then measurement capability is provided, but measurement precision is insufficient for low fluid flows and turndown ratio is limited
Solution Approach 1:
The fluid flow device is divided into multiple flow paths with different flow rates, allowing the system to handle a wide range of flows by selecting appropriate paths. This segmentation enables high turndown ratio while maintaining measurement precision across different flow conditions.
Solution Approach 2:
The patent introduces a multi-dimensional approach by adding flow path selection as an additional dimension to flow measurement. Instead of relying solely on a single measurement device with limited range, the system uses multiple flow paths with varying capacities to extend the effective measurement range and improve turndown ratio.
2Measurement precision
If expensive measurement devices are used to improve measurement accuracy, then measurement precision improves, but device complexity and manufacturing cost increase
Solution Approach 1:
By segmenting the flow measurement into multiple discrete paths with simple measurement points, the system achieves accurate measurement across a wide range without requiring a single complex expensive device. Each flow path uses straightforward measurement technology, reducing overall system complexity while maintaining precision.
Solution Approach 2:
The flow device structure serves multiple functions: it acts as both a flow distribution mechanism and a measurement platform. The same physical structure that directs flow also provides the measurement interface, eliminating the need for separate complex measurement equipment and reducing device complexity.
3Productivity
If conventional flow control is used in HVAC systems, then basic flow regulation is achieved, but energy efficiency deteriorates due to inability to accurately regulate low air flows
Solution Approach 1:
The HVAC system uses segmented flow paths that can be independently controlled and measured, enabling precise regulation of low air flows. This allows the system to optimize energy consumption by accurately matching supply air flow to actual zone requirements, improving overall energy efficiency.
Solution Approach 2:
The system incorporates measurement feedback from each flow path to enable closed-loop control. This feedback mechanism allows the HVAC system to continuously adjust flow rates based on actual conditions, ensuring accurate regulation and optimal energy efficiency while maintaining comfort.
Data Source
AI summary
A method for calibrating a product valve disposed along a flow path in a duct, with a calibration valve in a duct remote from the product valve and having a geometric shape and operational parameters corresponding to those of the product valve. A calibration controller establishes calibration conditions and, in responsive thereto, generates a calibration flow rate (CFM) function by measuring for the calibration valve, a sparse set of flow rates and determining a surface-fit mathematical representation of fluid flow through the calibration valve over applied calibrated flow rates and the measured pressure drops. The CFM Function is transferred to a product blade controller, which in turn, processes the representation of the mathematical surface, and controls fluid flow through product valve based on values extracted from the received CFM Function as well as at least one parameter control signal indicative of a desired set point.