Chilled Beam Integrated VAV Control for Pressure-Independent Air Flow
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Solution Overview
Problem
Conventional VAV systems with chilled beams face challenges in accurately controlling air flow to individual rooms due to pressure dependence, leading to inefficiencies and increased energy consumption, as they require multiple dampers and oversized ducts to maintain stable pressure, which occupy space and complicate installations.
Innovation Solution
An air treatment device with a chilled beam that measures static pressure and uses an actuator to adjust outlet configurations based on real-time flow measurements, eliminating the need for additional VAV dampers and allowing for pressure-independent operation by calculating actual air flow through the k-factor, enabling precise control of air flow without unnecessary pressure drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If individual VAV dampers are installed in each room to enable precise air flow control, then air flow control precision is improved, but device complexity and installation complexity increase
Solution Approach 1:
The patent combines the VAV damper functionality directly into the chilled beam unit, merging what were previously separate components (chilled beam + VAV damper) into a single integrated device. This eliminates the need for multiple separate dampers in the duct system while maintaining precise room-level air flow control through the actuator-controlled outlets on the chilled beam.
Solution Approach 2:
The chilled beam is designed to perform multiple functions: it provides cooling/heating through its heat exchanger, controls air flow volume through adjustable outlets, and integrates the VAV control mechanism within itself. This multi-functionality eliminates the need for separate dedicated VAV dampers while achieving the same control objectives.
2Measurement precision
If VAV dampers with orifice plates are used to measure and control air flow, then air flow measurement capability is improved, but energy consumption increases due to pressure drop
Solution Approach 1:
The patent removes the traditional orifice plate from the VAV damper design and replaces it with a different measurement approach. The air flow measurement capability is achieved through alternative means (such as pressure differential measurement across the chilled beam itself or using the actuator position in conjunction with known flow characteristics) that do not require creating excessive pressure drop through an orifice plate.
Solution Approach 2:
The patent changes the operating parameters of the control system by using the actuator position and pressure measurements to calculate air flow, rather than relying on fixed orifice plates. This allows for air flow control and measurement while minimizing unnecessary pressure drops and associated energy losses.
3Stability of the object's composition
If oversized ducts are used to reduce pressure dependence in ring systems, then pressure stability is improved, but installation space requirements increase
Solution Approach 1:
The patent introduces dynamic control capabilities to the chilled beam through the actuator, which can adjust the outlet configurations in real-time. This dynamic adjustment allows the system to maintain stable air flow delivery to rooms despite pressure variations in the duct system, eliminating the need for oversized ducts designed to maintain static pressure stability.
Solution Approach 2:
The system incorporates feedback mechanisms where the actuator position and pressure measurements are used to calculate actual air flow and make real-time adjustments. This feedback control allows the chilled beam to compensate for pressure variations dynamically, maintaining stable performance without requiring the pressure stability that oversized ducts would provide.
4Device complexity
If collective VAV control is used for groups of rooms, then device complexity is reduced, but air flow control accuracy for individual rooms deteriorates
Solution Approach 1:
The patent enables segmentation of air flow control at the individual room level by providing each chilled beam with its own actuator and control capabilities. This allows each room to be controlled independently rather than as part of a collective group, achieving precise room-level air flow control without requiring complex centralized control systems for each individual damper.
Solution Approach 2:
Each chilled beam unit is equipped with its own actuator and control system, making it self-sufficient for air flow regulation. The chilled beam can autonomously adjust its outlet configurations based on room conditions and requirements, eliminating the need for complex centralized control systems while maintaining accurate individual room control.
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
This solution allows for accurate and efficient control of air flow to individual rooms, reducing energy consumption and installation complexity, while handling larger airflow variations and maintaining consistent performance across varying pressures, thus enhancing comfort and operational efficiency.
Implementation Method 1
the air treatment device is arranged to measure the static pressure in the chilled beam pressure box
Implementation Method 2
The heat exchanger is liquid connected and cools or heats the air flowing through by heat exchange
Implementation Method 3
the supply air is supplied to the chilled beam and further out of the nozzle or nozzles of the beam to the room, an induction flow of room air is created and which is drawn through the chilled beam and an integrated heat exchanger therein
Data Source
AI summary
Method and air treatment device (1) for control of supply air flow (L1). The air treatment device (1) comprises a chilled beam (2) with a pressure box (5) comprising an inlet (6) for inflow of supply air flow (L1) and a plurality of outlets (7) for outflow of the supply air flow (L1) out of the pressure box (5). The air treatment device (1) comprises an actuator (12) for control of supply air flow (L1), and the pressure box (5) comprises at least one pressure measuring socket (13) for control of static pressure (ps). The air treatment device (1) registers the static pressure (ps) and the position of the actuator (12), and calculates the real supply air flow (L1). The actuator (12) is arranged to change the configuration of the outlets (7) by a linear motion of a cover member (9) and change the open area of the outlets (7).