Variable aperture fluid flow assembly
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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, leading to inefficient HVAC systems that consume excess energy and fail to provide comfort in buildings.
Innovation Solution
A fluid flow measurement and control system using a multi-stage damper with a variable opening area, controlled by an actuator assembly and a processor-based controller, which implements new correlations and equations to address historical contradictions in fluid flow phenomena, enabling precise measurement and control of fluid flows with a high turndown ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional fluid flow measurement devices are used, then measurement functionality is provided, but the devices are expensive and have limited turndown ratio (less than 10:1)
Solution Approach 1:
The fluid flow control system is divided into multiple stages with separate control elements (first control element and second control element) that can independently adjust flow parameters. This segmentation enables the system to achieve a high turndown ratio by coordinating the operation of multiple control stages, allowing accurate measurement and control across a wide range of flow conditions from very low to high flows.
2Measurement precision
If current flow measurement devices are used, then measurement is possible, but the cost is prohibitive and creates millions of unnecessary part numbers
Solution Approach 1:
The control system is designed as a universal multi-functional device that can accurately measure and control fluid flows across a wide range of conditions (turndown ratio greater than 10:1) using a single part number. The system incorporates multiple control elements and correlations that enable it to handle various flow scenarios without requiring numerous specialized components, thereby reducing complexity and inventory requirements.
3Measurement precision
If HVAC systems run at minimum measurable flow, then measurement accuracy is maintained, but energy consumption increases and comfort is hindered
Solution Approach 1:
The system dynamically adjusts the fluid flow control parameters based on real-time conditions, allowing the HVAC system to operate at optimal flow rates rather than being constrained to minimum measurable flows. The multi-stage control mechanism enables continuous adjustment of flow parameters, permitting the system to reduce energy consumption by lowering flows below traditional measurement thresholds while maintaining measurement accuracy through the sophisticated control algorithm and correlations.
4Stress or pressure
If large Total Pressure is used in current technology, then fluid flow control is achieved, but energy is significantly drained
Solution Approach 1:
The system changes the operating parameters by implementing precise control of fluid flow through multiple control elements and advanced correlations. This allows the system to achieve effective fluid flow control with reduced Total pressure requirements, thereby minimizing energy drain while maintaining measurement and control accuracy across the full turndown range.
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
The system allows for accurate measurement and regulation of fluid flows with a turndown ratio greater than 10:1, reducing energy consumption and improving HVAC system efficiency while providing comfort in buildings.
Implementation Method 1
a first sensor disposed upstream of, and a second sensor disposed downstream of, the orifice plate... determine a pressure differential based on a first pressure obtained between the first and second sensors
Implementation Method 2
an orifice plate positioned within the flow pathway and defining a variable opening for receiving flow therethrough... The orifice plate increases a pressure of the fluid flow for the purpose of measuring and controlling fluid flow
Data Source
AI summary
A variable aperture orifice plate assembly for controlling and/or measuring fluid flow therethrough, from an upstream end to a downstream end. The orifice plate assembly includes a damper assembly having an array of adjustable cross-section apertures having an aggregate aperture area, upstream and downstream pressure sensors on opposite sides of the damper assembly, an actuator assembly for adjustably controlling the aggregate area of the apertures, and a processor configured for feedback operation in a closed-loop, to effect operation as an orifice plate. The processor is responsive to differential pressure across the damper assembly, and the aggregate area of the respective apertures normal to the flow paths of fluid flowing therethrough, to control the differential pressure and/or the aggregate area in a closed-loop manner so that fluid flowing between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae.