Double-Flow Ventilation Pressure Control Without Flowmeters
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Solution Overview
Problem
Current double-flow controlled mechanical ventilation installations require flowmeters and bypass channels, leading to complex control systems and inefficiencies in airflow modulation and pressure management.
Innovation Solution
The system includes air supply and extraction networks with adjustable section members that react to external parameters like humidity and occupancy, automatically controlling fan flow rates to maintain balanced airflow and reference pressures, eliminating the need for flowmeters and simplifying the control loop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flowmeters and bypass channels are used to control airflow in double-flow ventilation installations, then airflow modulation capability is improved, but device complexity and control system complexity increase
Solution Approach 1:
The patent removes flowmeters and bypass channels from the system, extracting the problematic components that caused complexity. Instead of using these traditional flow control devices, the invention uses a different approach based on pressure measurement and fan speed control to achieve airflow modulation without the complex hardware.
Solution Approach 2:
The patent replaces mechanical flow control devices (flowmeters, bypass channels) with an electronic control system based on pressure sensors and variable speed fans. This substitution eliminates the need for complex mechanical flow measurement and adjustment mechanisms while maintaining airflow modulation capability.
2Measurement precision
If flowmeters are installed in multiple branches to measure airflow, then airflow measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent makes the pressure sensors serve multiple functions: they measure both pressure differential across the heat exchanger and infer airflow rates. This multi-functionality eliminates the need for dedicated flowmeters in each branch, reducing the number of measurement devices while maintaining measurement capability.
Solution Approach 2:
The patent uses pressure as an intermediary parameter to indirectly measure airflow. Instead of directly measuring airflow with flowmeters, the system measures pressure differential and uses this information to infer and control airflow rates, simplifying the measurement system.
3Adaptability or versatility
If bypass channels are used for flow rate adjustments, then airflow control flexibility is improved, but device complexity and energy loss increase
Solution Approach 1:
The patent uses dynamically controllable fan speeds instead of static bypass channels for flow rate adjustment. The fans can vary their rotation speed to precisely control airflow rates without creating energy losses associated with bypass flows, providing flexibility through dynamic control rather than static mechanical adjustments.
4Measurement precision
If multiple sensors and flowmeters are installed to balance airflows, then airflow balancing precision is improved, but device complexity increases
Solution Approach 1:
The patent makes pressure sensors serve multiple functions: measuring pressure differential across the heat exchanger, inferring airflow rates in both supply and extraction circuits, and providing feedback for balancing control. This multi-functionality reduces the number of sensors needed while maintaining balancing precision.
Solution Approach 2:
The patent implements a feedback control system where pressure sensor measurements are used to infer airflow rates and adjust fan speeds to maintain balanced airflow. This feedback mechanism enables precise airflow balancing using minimal sensors, as the system continuously monitors and adjusts based on pressure differential measurements.
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 enables efficient, self-regulating airflow modulation and pressure management, optimizing network dimensions and reducing noise and electrical consumption by automatically adjusting air passage sections and fan speeds, thus enhancing ventilation system performance.
Implementation Method 1
means for measuring the pressure in the network equipped with the member for modifying the passage section of the air
Implementation Method 2
control the fan of this network, called master fan, to modify the flow rate in this network and thus bring the pressure of this network back to a reference pressure
Implementation Method 3
a member for modifying the section of passage of the air, reacting automatically, that is to say that is, without external control, to external parameters such as the humidity or the occupancy rate of a room
Data Source
Figure 1~2
Figure 3~4
AI summary
The installation has a control housing (20) for controlling an air insufflation fan (12) of an air insufflation network (5) to modify air flow in the insufflation network so as to restore pressure of the network to reference pressure after variation of an air passage section (18) in the network according to pressure measured in the network. The housing controls an air extraction fan (13) of an air extraction network (8) to control the airflow provided by the extraction fan based on the flow provided by the insufflation fan after determination of airflow in the networks.