Multi-Stage Damper Flow Device for High-Turndown HVAC Measurement
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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 utilizing 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 flow measurement devices are used, then measurement capability is provided, but measurement precision deteriorates for low fluid flows due to limited turndown ratio
Solution Approach 1:
The flow measurement device is divided into multiple flow paths with different flow coefficients, allowing the system to segment the measurement range into multiple zones. Each flow path is optimized for specific flow ranges, enabling accurate measurement across a wide turndown ratio from 100:1 to 500:1 by selecting the appropriate flow path for the current flow condition.
Solution Approach 2:
The invention changes the flow coefficient parameter by providing multiple flow paths with different coefficients (Cv values). This allows the system to adapt to different flow conditions by switching between flow paths, maintaining measurement precision across a wide range of flow rates without requiring a single complex high-range device.
2Measurement precision
If high Total Pressure is used for flow measurement, then measurement capability is improved, but energy consumption increases significantly
Solution Approach 1:
The invention replaces the conventional mechanical pressure-based flow measurement system with an electronic flow sensor that measures flow directly without requiring high Total Pressure. This substitution eliminates the need to generate and maintain high pressure differentials, significantly reducing energy consumption while maintaining measurement accuracy across the full turndown range.
3Adaptability or versatility
If multiple flow paths with different flow coefficients are provided, then adaptability for different flow ranges is improved, but device complexity increases
Solution Approach 1:
The flow measurement device is designed as a universal multi-functional unit that can measure across a wide turndown ratio (100:1 to 500:1) using multiple flow paths with different flow coefficients. The controller automatically selects the appropriate flow path based on the current flow condition, providing a single device that replaces what would traditionally require multiple specialized measurement devices.
Solution Approach 2:
The controller automatically determines the appropriate flow path to use based on the current flow conditions without requiring manual intervention. The system self-adjusts by selecting the flow path with the appropriate flow coefficient, simplifying operation and reducing the need for complex manual configuration or switching mechanisms.
4Measurement precision
If conventional HVAC systems operate at minimum measurable flow, then measurement accuracy is maintained, but energy consumption increases and comfort is reduced
Solution Approach 1:
The system uses electronic flow sensors to provide real-time feedback on actual flow conditions to the controller. This feedback enables the controller to accurately modulate the HVAC system operation, allowing it to reduce flow below traditional minimum measurable levels while maintaining measurement accuracy. The system continuously adjusts based on actual flow measurements, preventing energy waste from operating at unnecessarily high minimum flow rates.
Data Source
AI summary
An air distribution apparatus that serves as a single sensing device for both lighting, LiFi, and HVAC functions that are operable on a single platform by building automation systems. The building automation system may be controllable by a single software system or network accessible locally on site or remotely off site. The air distribution apparatus can operate in a single zone or coupled with multiple like apparatuses for multi-zone operation. It is a high turndown, self-balancing system which allows for continuous commissioning with built-in fault diagnostic systems and that may be used as a supply, return, or exhaust system, or a combination thereof. The air distribution apparatus includes multi-stage airflow control systems that operate progressively based on unique actuation mechanisms and/or algorithms that allow for precise flow control and feedback to self-balance and commission the system.