Vehicle AC Mode Switching for Refrigerant Oil Return
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Solution Overview
Problem
In conventional vehicle air conditioning devices, the refrigerant oil may remain in the outside heat exchanger during the second dehumidifying-heating mode, leading to decreased lubricity in the compressor due to reduced refrigerant flow rates, which affects the heating capacity and efficiency.
Innovation Solution
The device switches between series and parallel dehumidifying-heating modes by controlling the decompressor opening degree and switching portion to increase refrigerant flow through the outside heat exchanger, ensuring refrigerant oil returns to the compressor, thereby preventing its accumulation in the heat exchanger.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the parallel dehumidifying-heating mode is used, then the heating capacity is improved, but the refrigerant oil accumulates in the outside heat exchanger causing decreased compressor lubricity
Solution Approach 1:
The system dynamically switches between parallel and series connection modes of the outside heat exchanger and evaporator based on operating conditions. The controller monitors refrigerant oil flow and automatically changes the circuit configuration to maintain proper lubrication while preserving heating performance.
Solution Approach 2:
The invention changes the flow path configuration parameter by switching between parallel and series connections. This parameter change alters the refrigerant flow characteristics, enabling sufficient refrigerant oil return to the compressor while maintaining the heating capacity provided by the parallel mode.
2Productivity
If the refrigerant flow rate through the outside heat exchanger is reduced, then the heating efficiency is improved, but the refrigerant oil return to compressor becomes insufficient
Solution Approach 1:
The system dynamically adjusts the refrigerant flow path by switching between parallel and series modes. When series mode is activated, the refrigerant flow rate through the outside heat exchanger increases, ensuring sufficient refrigerant oil return to the compressor while maintaining acceptable heating efficiency through controller management.
3Reliability
If the series dehumidifying-heating mode is used, then the refrigerant oil returns to compressor adequately, but the heating capacity is reduced
Solution Approach 1:
The system dynamically switches between series and parallel connection modes based on real-time operating conditions. The controller activates series mode only when refrigerant oil return is insufficient, accepting temporary reduction in heating capacity to protect compressor lubrication, then switches back to parallel mode when conditions permit.
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 solution enhances the return of refrigerant oil to the compressor, maintaining compressor lubricity and improving heating capacity by adjusting the operational mode based on refrigerant oil flow, thus addressing the issue of refrigerant oil retention in the outside heat exchanger.
Implementation Method 1
a compressor (11), which draws, compresses, and discharges a refrigerant
Implementation Method 2
a radiator (12), which heats air by exchanging heat between the refrigerant discharged from the compressor and the air sent to a passenger compartment
Implementation Method 3
an outside heat exchanger (20), which exchanges heat between outside air and the refrigerant flowing out of the radiator
Implementation Method 4
an evaporator (23), which evaporates the refrigerant by exchanging heat between the refrigerant flowing out of the outside heat exchanger and the air flowing through the radiator
Implementation Method 5
a first decompressor, which decompresses the refrigerant flowing out of the radiator, and a second decompressor, which decompresses the refrigerant flowing out of the outside heat exchanger
Data Source
AI summary
A vehicle air conditioning device includes a compressor, a radiator, an outside heat exchanger, an evaporator, a first decompressor, a second decompressor, a switching portion, and a controller. The radiator exchanges heat between a refrigerant discharged from the compressor and air. The outside heat exchanger exchanges heat between outside air and the refrigerant flowing out of the radiator. The evaporator is exchanges heat between the refrigerant flowing out of the outside heat exchanger and the air flowing through the radiator. The switching portion switches between a series dehumidifying-heating mode and a parallel dehumidifying-heating mode. The controller is configured to control the switching portion to switch from the parallel dehumidifying-heating mode to the series dehumidifying-heating mode when the amount of the refrigerant oil flowing from the outside heat exchanger to the compressor is insufficient in the parallel dehumidifying-heating mode.