Rotational speed control method for external fan of air conditioner
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Solution Overview
Problem
Existing air conditioners suffer from low adjustment accuracy in controlling the rotational speed of external fans, leading to significant differences between speed settings, which adversely affect system pressure and stability.
Innovation Solution
A method for controlling the rotational speed of an external fan based on comparing refrigerant pipeline pressure values with preset thresholds determined by outdoor ambient temperature, adjusting the fan speed by small increments to match system pressure, and correcting thresholds based on superheat degrees to ensure stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotational speed of the external fan is adjusted using multiple discrete speed settings, then the control is simplified and easier to operate, but the adjustment accuracy decreases and causes large differences in rotational speed between settings
Solution Approach 1:
The patent changes the control parameter from discrete speed settings to continuous rotational speed adjustment based on pressure differential feedback. The controller continuously adjusts the rotational speed of the external fan according to the detected pressure differential between indoor and outdoor environments, enabling precise control while maintaining operational simplicity through automated feedback control.
2Productivity
If the rotational speed of the external fan is increased to improve heat exchange efficiency, then the cooling or heating performance improves, but the system pressure becomes unstable and affects overall system reliability
Solution Approach 1:
The patent introduces a feedback control mechanism where a pressure sensor detects the pressure differential between indoor and outdoor environments, and the controller adjusts the external fan's rotational speed based on this feedback. This closed-loop control ensures that the fan speed is dynamically optimized to maintain stable system pressure while achieving efficient heat exchange, thereby improving both productivity and reliability.
3Device complexity
If discrete speed settings are used for the external fan, then the device complexity is reduced, but the ability to adapt to varying ambient conditions and system pressures is compromised
Solution Approach 1:
The system performs self-adjustment through automated feedback control. The pressure sensor continuously monitors the pressure differential, and the controller automatically adjusts the external fan speed without requiring manual intervention or complex control mechanisms. This self-service approach maintains low device complexity while achieving high adaptability to varying ambient conditions through continuous automated optimization.
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
Enables stepless speed adjustment of the external fan, matching its speed to the air conditioning system's pressure, thereby ensuring stable operation and optimal performance under varying ambient conditions.
Implementation Method 1
an amount of heat exchange between a refrigerant and the environment is reduced by adjusting the settings of the rotational speed of the external fan
Implementation Method 2
obtaining a pressure value of a refrigerant pipeline between the compressor and the outdoor heat exchanger
Data Source
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AI summary
The present disclosure relates to the technical field of air conditioning; in particular, the present disclosure relates to a method for controlling a rotational speed of an external fan of an air conditioner. The present disclosure aims to solve the problem of low adjustment accuracy of external fans of existing air conditioners. To this end, the method for controlling the rotational speed includes: obtaining a pressure value of a refrigerant pipeline between the compressor and the outdoor heat exchanger after the external fan starts; comparing the pressure value with a preset pressure threshold; and selectively controlling the rotational speed of the external fan to increase or decrease by a rotational speed adjustment amount based on a comparison result; in which the preset pressure threshold is determined based on an outdoor ambient temperature. By selectively controlling the rotational speed of the external fan to increase or decrease by the rotational speed adjustment amount based on the pressure value and the preset pressure threshold, the control method of the present application can realize a stepless speed adjustment of the external fan, so that the rotational speed of the external fan can match the pressure value of the air conditioning system, the influence of the rotational speed of the external fan on the pressure of the air conditioning system can be reduced, and a stable operation of the air conditioning system can be ensured.