Control method for air conditioner
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Solution Overview
Problem
Air conditioners face issues with freezing of the indoor unit, outdoor unit, and unit connection pipe due to low ambient temperatures, long piping, and freon shortages, leading to poor cooling effects, water leakage, and pipe cracks, which existing control methods fail to adequately address.
Innovation Solution
A control method that adjusts the compressor frequency based on the suction temperature of the outdoor unit, with specific preset temperature ranges to prevent freezing, including decreasing, maintaining, or increasing frequency accordingly, and incorporating ambient temperature adjustments to determine these ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If indoor unit coil temperature sensor or pressure switch are used for anti-freezing control, then freezing protection is provided, but the sensors are prone to failure and cannot accurately detect temperature or pressure
Solution Approach 1:
The patent extracts the anti-freezing control function from traditional temperature sensors and pressure switches, and implements it through a new mechanism based on compressor frequency adjustment. Instead of relying on separate detection devices, the system uses the relationship between compressor operation and refrigerant state to infer freezing conditions and respond accordingly.
Solution Approach 2:
The patent makes the compressor serve multiple functions: not only compressing refrigerant but also acting as a reference for detecting freezing conditions. By monitoring compressor frequency and its relationship with refrigerant flow, the system can identify freezing situations without requiring separate temperature or pressure sensors.
2Adaptability or versatility
If long piping is used for air conditioner installation, then installation flexibility is improved, but pressure loss occurs causing freezing of suction pipe and outdoor unit
Solution Approach 1:
The patent implements a feedback mechanism where the system continuously monitors compressor frequency and compares it with expected values. When deviation indicates freezing conditions (caused by long piping pressure loss), the system adjusts compressor frequency to correct the issue, creating a closed-loop control that adapts to installation variations.
3Quantity of substance
If air conditioning system lacks freon, then operating cost is reduced, but temperature detection becomes inaccurate causing freezing
Solution Approach 1:
The patent replaces the traditional thermal-based temperature detection system with a mechanical-based approach using compressor frequency monitoring. Instead of measuring temperature directly (which becomes unreliable when freon is low), the system measures the mechanical response of the compressor to infer refrigerant state and freezing conditions.
4Reliability
If pressure switch is used for anti-freezing control, then freezing protection is provided, but the pressure switch is prone to failure
Solution Approach 1:
The patent removes the pressure switch from the system entirely, extracting the anti-freezing function from mechanical pressure detection and implementing it through electronic control based on compressor frequency monitoring. This eliminates the failure-prone pressure switch while maintaining protection functionality.
Data Source
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Figure 3~4
AI summary
A control method for an air conditioner comprising a compressor and an outdoor unit, wherein the control method comprises: obtaining a suction temperature of the outdoor unit; and selectively adjusting the frequency of the compressor according to the suction temperature of the outdoor unit. The method can adjust the operating frequency of the compressor according to the temperature interval in which the suction temperature of the outdoor unit is located, to avoid the freezing of an indoor unit, the outdoor unit and an unit connecting tube of the air conditioner, thereby effectively solving the problem that the indoor unit, the outdoor unit and the unit connecting tube of the air conditioner are easy to freeze, and the stability and reliability of the air conditioner operation are also improved.