Control method for air conditioning system, and air conditioning system
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Solution Overview
Problem
In air conditioning systems with multi-channel heat exchangers, the heat exchange performance is poor during startup, leading to frosting and reduced system capability during heating operations due to excessive suction phenomena.
Innovation Solution
A control method that limits the compressor's operating frequency to less than 75 Hz and frequency rise speed to less than 1.25 Hz/s during the initial 60 seconds of startup, and further adjusts these parameters based on operating time to prevent excessive frequency rise and reduce suction, thereby avoiding frosting and improving system reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the compressor operates at high frequency during startup, then the system reaches operating temperature faster, but the heat exchanger frosting accelerates and system capability attenuates
Solution Approach 1:
The control method applies preliminary action by implementing frequency limiting and rate-of-change control during the startup phase (first 60 seconds) before the system reaches stable operation. This preliminary control prevents frosting accumulation before it can significantly impact heat exchanger performance, thereby protecting system capability while still allowing the system to warm up.
2Speed
If the compressor frequency rises quickly during startup, then the system responds faster to heating demand, but excessive suction phenomena occur causing heat exchanger frosting
Solution Approach 1:
The control method changes the frequency parameter characteristics during startup by limiting both the maximum frequency (to 75 Hz) and the rate of frequency change (to 1.25 Hz/s). This parameter control modifies the compressor's operating characteristics to prevent excessive suction phenomena that would otherwise cause frosting on the heat exchanger during the critical startup phase.
Data Source
AI summary
The present disclosure discloses a control method for an air conditioning system. The air conditioning system at least includes a compressor, a heat exchanger and a throttle device. The operation phase of the air conditioning system at least includes a start-up phase and a stable phase. The control method includes an action that in the start-up phase, the operating time of the compressor is set as t, when t is greater than 0 and less than 60s, an operating frequency F of the compressor is controlled to be less than 75 Hz, and a frequency rise speed per second Vf of the compressor is controlled to be less than 1.25 Hz/s.