Heat Pump Dryer Lubricant Return for Compressor Wear Reduction
Solution Overview
Problem
Conventional clothes treating apparatuses with heat pumps face a decrease in compressor durability and efficiency due to lubricant discharge into the refrigerant pipe, leading to reduced heat exchange performance.
Innovation Solution
A method and apparatus that control the clothes treating apparatus by optimizing the operation of the compressor, expansion valve, and fan to minimize residual lubricant in the refrigerant pipe, including steps for circulation, heat exchange, retrieval of refrigerant and lubricant, and filter cleaning to maintain lubricant levels and improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the compressor operates continuously to maintain lubricant supply to the compression chamber, then the durability of the compressor is maintained, but the lubricant is discharged together with the refrigerant into the refrigerant pipe, leading to decreased compressor durability and heat exchange efficiency
Solution Approach 1:
The patent applies preliminary action by retrieving lubricant from the refrigerant pipe into the compressor before the compressor operates. This is achieved by closing the expansion valve to isolate the refrigerant pipe, then operating the compressor to create pressure differential that draws lubricant back into the compressor. This preliminary retrieval prevents lubricant discharge during subsequent compression operations, resolving the contradiction between maintaining lubricant supply and preventing lubricant loss.
Solution Approach 2:
The patent implements the discarding and recovering principle by temporarily discarding refrigerant flow through the expansion valve closure, then recovering lubricant from the refrigerant pipe into the compressor. The expansion valve is closed to prevent refrigerant flow, the compressor operates to retrieve lubricant, and then the expansion valve is reopened. This cycle allows lubricant recovery without continuous discharge, resolving the contradiction between lubricant supply and lubricant retention.
2Productivity
If the expansion valve remains open to allow refrigerant circulation, then heat exchange efficiency is maintained, but lubricant continues to discharge into the refrigerant pipe, reducing compressor durability
Solution Approach 1:
The patent applies periodic action by cyclically closing and opening the expansion valve. During the closed phase, lubricant is retrieved into the compressor. During the open phase, refrigerant circulates for heat exchange. This periodic cycling allows the system to alternately prioritize lubricant recovery and heat exchange efficiency, resolving the contradiction between continuous refrigerant flow and lubricant retention.
Solution Approach 2:
Before resuming normal refrigerant circulation, the patent performs preliminary lubricant retrieval by closing the expansion valve and operating the compressor. This preliminary action ensures lubricant is recovered into the compressor before the expansion valve is reopened, preventing subsequent lubricant discharge while maintaining heat exchange efficiency during normal operation.
3Speed
If the compressor operates at high speed to compress refrigerant efficiently, then refrigerant circulation is improved, but lubricant is more readily discharged into the refrigerant pipe
Solution Approach 1:
The patent applies preliminary action by retrieving lubricant at low compressor speed before high-speed compression operations. The expansion valve is closed and the compressor operates at relatively low speed to retrieve lubricant without excessive force. Once lubricant is recovered, the expansion valve is reopened and normal high-speed compression resumes, preventing lubricant discharge during high-speed operation.
Solution Approach 2:
The patent applies dynamics by adjusting compressor operating conditions based on system state. During lubricant retrieval, the compressor operates at controlled speed with the expansion valve closed. During normal operation, the compressor operates at optimal high speed with the expansion valve open. This dynamic adjustment of operating parameters resolves the contradiction between compression efficiency and lubricant retention.
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 solution effectively minimizes residual lubricant in the refrigerant pipe, enhancing the durability and efficiency of the compressor and heat exchange process, thereby improving the overall performance of the clothes treating apparatus.
Implementation Method 1
an evaporator configured to evaporate refrigerant by exchanging heat with air
Implementation Method 2
an evaporator configured to evaporate refrigerant by exchanging heat with air
Implementation Method 3
a condenser configured to condense the refrigerant by exchanging heat with air passed through the evaporator
Implementation Method 4
a condenser configured to condense the refrigerant by exchanging heat with air passed through the evaporator
Implementation Method 5
a compressor configured to compress the refrigerant discharged from the evaporator and transferring the compressed refrigerant to the condenser
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The present invention relates to a method for controlling a clothes treating apparatus, the method comprising: a circulation step of circulating air by operating a fan; a heat exchange step of opening a refrigerant pipe by controlling an expansion valve, and circulating a refrigerant by operating a compressor; a circulation termination step of terminating the operation of the fan when the dryness level of clothes stored in a receiving part reaches a predetermined reference dryness level or when the elapsed time of the heat exchange step reaches a predetermined reference time; and a return step of closing the refrigerant pipe by controlling the expansion valve, and returning the refrigerant and lubricant in the refrigerant pipe to the compressor by operating the compressor.