Method for controlling linear compressor and refrigerator
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Solution Overview
Problem
Linear compressors face issues with bearing refrigerant function at low ambient temperatures, leading to piston malfunction and damage due to insufficient refrigerant flow and condensation, which obstructs the bearing flow path.
Innovation Solution
A method for controlling the linear compressor by measuring ambient temperature and applying a safety current to heat the coil and expand the bearing refrigerant, ensuring a stable floating force for the piston, even at low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ambient temperature is lowered, then the refrigeration efficiency is improved, but the bearing refrigerant flow is reduced and condensation occurs, causing piston malfunction
Solution Approach 1:
The control method proactively detects low ambient temperature conditions and preemptively applies a safety current to heat the coil before condensation can occur. This preliminary heating action prevents the bearing refrigerant from condensing and blocking the flow path, ensuring continuous reliable piston operation during efficient low-temperature refrigeration cycles.
Solution Approach 2:
The system changes the electrical parameter (current) applied to the coil based on ambient temperature conditions. By switching from normal operating current to a higher safety current when low temperature is detected, the system heats the coil to maintain bearing refrigerant in gaseous state, preventing condensation while preserving refrigeration efficiency at low ambient temperatures.
2Reliability
If a high current is applied to heat the coil and expand bearing refrigerant, then the bearing function is improved, but the energy consumption increases
Solution Approach 1:
The safety current is applied periodically or intermittently rather than continuously. The control method monitors ambient temperature and applies the high safety current only during low-temperature periods when condensation risk exists, then reduces or stops the additional heating when temperatures rise. This periodic application maintains bearing refrigerant function while minimizing unnecessary energy consumption during normal operating conditions.
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
This control method ensures smooth operation and prevents piston damage by maintaining adequate refrigerant flow and preventing condensation, thereby ensuring the bearing refrigerant functions effectively at low ambient temperatures.
Implementation Method 1
applying a safety current higher than a maximum applied current M to the motor assembly, thereby heating the coil
Implementation Method 2
heating the coil and expand the bearing refrigerant, ensuring a stable floating force for the piston
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A method for controlling a linear compressor (10) includes measuring (S120) an ambient temperature, and, when (S130) the measured ambient temperature is equal to or lower than a preset safety temperature (A), applying (S140) a safety current to the motor assembly for driving the piston. On the other hand, when (S150) the measured ambient temperature is higher than the preset safety temperature (A), a current lower than the safety current is applied (S160) to the motor assembly. A method for controlling a refrigerator including a linear compressor is also disclosed, wherein the linear compressor is controlled as defined above.