Method for controlling air output volume
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Solution Overview
Problem
Existing air-conditioning fan systems face challenges in maintaining constant air volume under varying static pressures due to dust deposition and filter blockages, which requires costly and complex microprocessor control units for accurate air volume control.
Innovation Solution
A method that establishes a functional relation formula Q=F(T, n, V) to calculate air volume by testing torque and rotational speed relationships, using a microprocessor control unit to adjust rotational speed and torque, allowing the system to adapt to changing static pressures with high efficiency and accuracy while minimizing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an air volume meter is installed to maintain constant air volume, then air volume control accuracy is improved, but system cost and failure risk increase
Solution Approach 1:
The patent extracts the air volume measurement function from a dedicated air volume meter and implements it through the existing motor control system by measuring torque and rotational speed, which are already available in the motor control process. This eliminates the need for separate air volume measurement hardware while maintaining control accuracy.
Solution Approach 2:
The patent uses torque and rotational speed as intermediary parameters to indirectly measure air volume. Instead of directly measuring air volume with a meter, the system measures torque and rotational speed (which are easily obtainable from the motor control system) and calculates air volume through established relationships, serving as a cost-effective intermediary measurement approach.
2Measurement precision
If direct static pressure measurement is used to determine air volume, then air volume control is achieved, but a powerful microprocessor control unit is required increasing cost
Solution Approach 1:
The patent changes the measurement parameters from direct static pressure measurement to torque and rotational speed measurement. By measuring torque and rotational speed instead of static pressure, the system can calculate air volume using simpler computational methods that do not require a powerful microprocessor, thereby reducing control unit requirements and system cost.
3Ease of operation
If rotational speed is adjusted by monitoring static pressure changes, then air volume control is achieved, but the system requires complex pre-measurement and calibration
Solution Approach 1:
The patent performs preliminary action by establishing the relationship between torque, rotational speed, and air volume during the system design phase. The control algorithm and calculation relationships are pre-configured in the motor controller, eliminating the need for complex runtime calibration and pre-measurement procedures during operation.
Data Source
AI summary
A method for controlling air volume including: 1) inputting a target air volume into a microprocessor control unit of a motor controller; 2) starting a motor by the motor controller and allowing the motor to work in a steady state under a rotational speed; 3) recording the torque and rotational speed in the steady state, establishing a functional relation formula Q=F (T, n, V) for calculating the air volume, and calculating an air volume in the steady state; 4) comparing the target air volume with the calculated air volume; 5) re-recording a steady torque after the motor falls on a new steady state under an increased or reduced rotational speed, and recalculating the air volume in the new steady state; and 6) repeating steps 4) and 5) to adjust the rotational speed until the calculated air volume is equal or equivalent to the target air volume.