Air Conditioner Compressor Pressure Control for Low-Load Operation
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Solution Overview
Problem
Air conditioners face challenges in efficiently controlling compressor operation during low-load conditions, leading to increased pressure fluctuations and potential oil formation, which can reduce reliability and efficiency.
Innovation Solution
A method that involves determining low-load conditions and performing a low-load operation at a preset frequency, with the option to bypass refrigerant from the compressor to a gas/liquid separator through an injection and bypass passage, using valves to adjust flow rates and pressures to maintain target pressure ranges, thereby controlling compressor operation factors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the compressor operates at the lowest frequency during low-load operation, then energy consumption is reduced, but pressure fluctuations increase and oil formation occurs
Solution Approach 1:
The patent applies dynamics by making the compressor operation frequency adjustable rather than fixed at the lowest frequency. The control unit dynamically adjusts the operation frequency based on real-time pressure feedback from sensors, allowing the system to transition between low-frequency (energy-saving) and higher-frequency (pressure-stabilizing) modes, thus resolving the contradiction between energy consumption and reliability
Solution Approach 2:
The patent implements a feedback control mechanism where pressure sensors continuously monitor the refrigerant pressure and provide data to the control unit. The control unit compares the actual pressure with target pressure values and adjusts the compressor frequency accordingly, creating a closed-loop system that maintains reliability while enabling energy-saving operation
2Loss of energy
If the compressor operates at the lowest frequency, then operating cost is reduced, but pressure control precision deteriorates
Solution Approach 1:
The system dynamically adjusts compressor frequency based on actual pressure conditions rather than operating at a fixed lowest frequency. This dynamic adjustment allows the system to maintain precise pressure control when needed while operating at lower frequencies during stable conditions, thereby reducing energy loss without sacrificing pressure control precision
Solution Approach 2:
The patent changes the operating parameters (frequency and pressure setpoints) based on system conditions. The control unit adjusts both the compressor frequency and target pressure values dynamically, allowing the system to optimize between energy consumption and pressure control precision by varying these parameters in response to real-time feedback
3Productivity
If the high pressure rises above target pressure, then refrigerant circulation is maintained, but compressor reliability deteriorates
Solution Approach 1:
The patent uses feedback control where pressure sensors monitor the actual high pressure and provide continuous data to the control unit. When the pressure exceeds the target range, the control unit receives this feedback and adjusts the compressor frequency or activates bypass mechanisms to reduce pressure, thereby protecting compressor reliability while maintaining refrigerant circulation
Solution Approach 2:
The system takes preliminary anti-action by implementing pressure monitoring and control mechanisms that prevent pressure from rising to dangerous levels in the first place. The control unit proactively adjusts operation parameters before abnormal pressure conditions can cause damage, rather than waiting for failure conditions to occur
Data Source
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AI summary
Provided is an air conditioner and a method of controlling the same. The method of controlling an air conditioner includes determining whether a low-load condition is satisfied on the basis of the number of indoor units or a temperature of external air, performing a low-load operation of a compressor at a preset frequency when the low-load condition is satisfied, detecting whether the operation pressure is out of a target pressure value or range while the low-load operation is performed, and bypassing a refrigerant from the compressor to a gas/liquid separator via an injection passage when the operation pressure is out of the target pressure value or range.