Compressor having a pressurized case
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Solution Overview
Problem
Refrigerant recovery units in air conditioning systems suffer from inefficiencies due to refrigerant leakage through imperfect piston seals and the lack of control over pressure in the compressor case, leading to increased costs and reduced recovery efficiency.
Innovation Solution
A compressor system with a valve configuration that controls the flow between the compressor case and the inlet/outlet passages based on pressure thresholds, using sensors to manage the pressure difference and minimize leakage, allowing for optimized pressure management during the recovery operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the compressor case is sealed with a bleedback hole to allow refrigerant to escape back to the inlet, then pressure in the crank case increases to assist compression efficiency, but refrigerant is continuously lost through the bleedback hole and the compressor cannot produce a vacuum at the end of recovery operation
Solution Approach 1:
The patent applies a solenoid valve to dynamically control the bleedback passage, switching it between open and closed states based on operational requirements. During recovery, the valve opens to allow refrigerant flow for compression assistance; during vacuum production, the valve closes to prevent refrigerant loss and enable vacuum formation. This dynamic control resolves the contradiction between maintaining compression efficiency and preventing refrigerant loss.
2Reliability
If the compressor case is open to atmosphere, then refrigerant leakage through piston rings does not build up pressure, but compressed refrigerant leaks continuously into the case and is lost to atmosphere
Solution Approach 1:
The patent converts the harmful refrigerant leakage through piston rings into a beneficial pressure source for the crank case. By sealing the compressor case and utilizing the leaked refrigerant to pressurize the crank case, the system transforms a loss into a functional advantage that assists compression. The solenoid valve then controls this pressurized refrigerant through the bleedback passage only when needed, preventing atmospheric loss.
3Power
If a bleedback hole is provided to allow pressure equalization, then the compressor can operate with pressure assistance, but control or selection of pressure in the crank case is not possible
Solution Approach 1:
The patent incorporates a solenoid valve that responds to operational conditions to control the bleedback passage. The valve receives control signals based on system state (recovery mode vs. vacuum mode), creating a feedback mechanism that automatically adjusts pressure in the crank case. This enables precise pressure control while maintaining compression assistance when needed, resolving the contradiction between power assistance and operational control.
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 reduces refrigerant losses and enhances the efficiency of the compressor by controlling pressure within the compressor case, improving the recovery process and extending the life of the refrigerant by minimizing leakage and maintaining system performance.
Implementation Method 1
A low side return passage fluidly connects the compressor case with the low side passage and a first valve is positioned at least partially in the low side return passage and configured to control flow in the low side return passage
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3C
AI summary
A compressor system for an air conditioning service system includes a compressor having a compressor case and a compressor head, an inlet, an outlet, a low side passage fluidly connecting the inlet to the compressor head, and a high side passage fluidly connecting the outlet to the compressor head. A low side return passage fluidly connects the compressor case with the low side passage and a first valve is positioned at least partially in the low side return passage and configured to control flow in the low side return passage.