Compressor Preheating Power Control for Liquid Refrigerant Removal
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Solution Overview
Problem
Conventional air conditioner compressor heating methods fail to efficiently eliminate liquid refrigerant accumulation regardless of rotor position, leading to potential compressor breakage due to uneven power input and refrigerant accumulation.
Innovation Solution
An air conditioner system incorporating an inverter circuit, power detecting unit, PWM-signal generating unit, voltage-command-value generating unit, and accumulation detecting unit to control inverter power and generate PWM signals for preheating, ensuring consistent power delivery and refrigerant evaporation regardless of rotor position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a fixed alternating-current voltage is applied to the compressor at regular time intervals, then the compressor can be heated, but the power input varies depending on rotor position causing liquid refrigerant to remain
Solution Approach 1:
The patent applies dynamic control by adjusting the alternating-current voltage frequency and amplitude based on detected rotor position. The control unit varies the voltage parameters dynamically during different rotor positions to maintain consistent heating power, transforming the static fixed-voltage approach into a dynamic adaptive system that compensates for inductance variations.
Solution Approach 2:
The patent implements feedback control by detecting the rotor position and using this information to adjust the voltage applied to the compressor. The control unit continuously monitors rotor position and modifies the alternating-current voltage parameters in real-time, creating a closed-loop system that ensures consistent heating regardless of rotor position.
2Use of energy by stationary object
If the compressor is heated with fixed voltage, then heating is provided, but uneven power input occurs due to varying inductance values at different rotor positions
Solution Approach 1:
The patent changes the electrical parameters (frequency and amplitude) of the alternating-current voltage based on rotor position. By adjusting these parameters dynamically, the system compensates for inductance variations and maintains consistent power input, achieving both efficient heating and uniform energy distribution throughout the compressor.
3Reliability
If high-frequency alternating-current voltage is applied continuously, then liquid refrigerant can be evaporated, but excessive energy consumption and potential damage occur
Solution Approach 1:
The patent applies periodic heating action by alternating between heating periods and normal operation periods. The control unit applies high-frequency voltage only during detected liquid refrigerant accumulation conditions, creating a periodic rather than continuous heating cycle, which reduces overall energy consumption while maintaining effective refrigerant elimination.
Solution Approach 2:
The patent uses partial action by applying heating voltage only when and where needed (during liquid refrigerant accumulation events) rather than continuously. This targeted approach uses minimal necessary energy to achieve the required refrigerant evaporation without excessive energy consumption or potential damage from continuous high-frequency operation.
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
The system achieves reliable refrigerant elimination within the compressor, reducing the risk of breakage and noise, while optimizing energy usage and compliance with regulatory standards, ensuring efficient and reliable operation.
Implementation Method 1
an inverter circuit that drives a motor of the compressor
Implementation Method 2
a PWM-signal generating unit that generates PWM signals for controlling the inverter circuit
Implementation Method 3
heating the compressor with a fixed voltage... eliminate a liquid refrigerant within a compressor
Data Source
AI summary
An air conditioner equipped with a compressor, an indoor heat exchanger and an outdoor heat exchanger includes: an inverter circuit that drives a motor of the compressor; an inverter-power detecting unit that detects power of the inverter circuit; a PWM-signal generating unit that inverter-current detecting unit generates PWM signals for controlling the inverter circuit; a voltage-command-value generating unit that outputs voltage command values to the PWM-signal generating unit; and an accumulation detecting unit that detects accumulation of a liquid refrigerant within the compressor and outputs a detection result to the voltage-command-value generating unit, wherein when accumulation of a liquid refrigerant within the compressor is detected, the voltage-command-value generating unit outputs the voltage command value so that power of the inverter circuit has a predetermined power value.