Sensor Adaptor Element for Ventilation Flow Measurement
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Solution Overview
Problem
Existing methods for measuring main fluid flow through ventilation installations, such as centrifugal fans, are not accurate due to limitations in determining differential pressure between the suction opening and ambient pressure, leading to inconsistencies in flow rate calculations.
Innovation Solution
A sensor adaptor element is designed to couple a differential pressure sensor with a centrifugal fan's casing, creating a pressure tapping duct with inlet and outlet openings that induce a Venturi effect, allowing for precise measurement of pressure differences associated with the main fluid flow, using either flow-through or static membrane sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a measurement probe is brought deeply into the fluid flow to probe local pressure, then the measurement can capture the pressure at the suction opening, but the probe placement becomes complex and measurement accuracy is compromised by flow disturbances
Solution Approach 1:
The patent introduces a pressure tapping duct as an intermediary element that connects the measurement system to the fluid flow without requiring direct probe insertion into the suction opening. The duct allows pressure to be tapped at a remote location while maintaining measurement accuracy, eliminating the need for complex probe placement deep in the flow field.
Solution Approach 2:
The measurement system is segmented into separate functional components: the pressure tapping duct for pressure acquisition, the differential pressure sensor for measurement, and the adapter element for integration. This segmentation allows each component to be optimized independently and simplifies installation compared to a single complex probe.
2Measurement precision
If the outlet opening is placed in the main fluid flow to induce Venturi effect, then under pressure is created for accurate measurement, but the opening may interfere with the main flow
Solution Approach 1:
The outlet opening is designed with specific local geometric properties (slot-like shape with particular dimensions and orientation) that create the Venturi effect and under pressure locally, while the overall structure remains minimally intrusive to the main fluid flow. The local quality of the opening geometry enables measurement functionality without significantly impacting global flow efficiency.
3Device complexity
If conventional differential pressure sensors are used, then the device is simple and cost-effective, but measurement noise is high and accuracy is reduced
Solution Approach 1:
The pressure tapping duct acts as a mediator that conditions the fluid flow before it reaches the sensor, creating a stable under pressure environment that reduces measurement noise. This intermediary structure allows conventional sensors to achieve better accuracy by improving the quality of the input signal.
Solution Approach 2:
The system performs preliminary action by creating the Venturi effect and establishing under pressure in the tapping duct before the pressure reaches the sensor. This pre-conditioning of the fluid flow stabilizes the measurement conditions and reduces noise, allowing conventional sensors to perform more accurately.
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 sensor adaptor element enhances the accuracy of main fluid flow measurement by stabilizing the Venturi effect and reducing measurement noise, providing a direct and reliable measure of the pressure difference, which is essential for determining the total flow rate through the ventilation installation.
Implementation Method 1
the outlet opening is a slot-like opening... such that a Venturi effect occurs at the outlet opening causing an under pressure in at least part of said pressure tapping duct
Data Source
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AI summary
A sensor adaptor element (1) for a differential pressure sensor, the sensor adaptor element (1) being attachable to a ventilation installation, having a base element (10), and comprising or being adapted to create with a casing of the installation a pressure tapping duct with an inlet opening (113) and with pressure tapping ports (109, 110) for probing local pressures in the duct. The pressure tapping duct comprises an outlet opening (121) that may be placed in a main fluid flow entering the ventilation installation such that a Venturi effect occurs and sucks fluid into the inlet opening (113) and through said pressure tapping duct. The invention further relates to a mass flow sensor and a ventilation installation with such a sensor adaptor element (1).