Variable economizer injection position
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Solution Overview
Problem
In refrigeration and HVAC systems, the economizer's benefits are not fully utilized when the compressor is unloaded, as the fixed economizer injection position becomes ineffective, leading to reduced efficiency due to changing pressure ratios during compression.
Innovation Solution
A compressor with a variable economizer injection position that adjusts along the compression path as the compressor unloads, ensuring the economizer benefits are maintained by selecting appropriate injection ports using flow regulating devices, such as spool valves or solenoid valves, to match the economizer pressure with the compression chamber pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the economizer injection position is fixed, then the economizer benefits are fully utilized when the compressor is at full load, but the economizer becomes ineffective when the compressor is unloaded
Solution Approach 1:
The injection port is made movable along the compression chamber wall, allowing its position to be dynamically adjusted based on compressor load conditions. This dynamic positioning ensures the injection port remains within the closed pocket region regardless of whether the compressor is operating at full load or unloaded conditions, thereby maintaining economizer effectiveness across varying operating conditions.
Solution Approach 2:
The system changes the spatial parameter (injection port position) along the compression path based on operating conditions. By adjusting the injection port position parameter, the system adapts to different pressure profiles that occur during loading and unloading, ensuring optimal injection timing and location for maintaining compressor capacity benefits.
2Ease of operation
If the compressor is unloaded by moving the slide valve, then the capacity is reduced, but the pressure profile changes make the fixed economizer injection position ineffective
Solution Approach 1:
The injection port moves dynamically in response to slide valve position changes. When the slide valve moves to unload the compressor, the injection port也随之 moves to maintain its position within the closed pocket, ensuring that the economizer continues to provide capacity benefits even during unloading operations.
Solution Approach 2:
The system employs feedback mechanisms where the slide valve position and compression chamber pressure profile are monitored, and the injection port position is adjusted accordingly. This feedback loop ensures that the injection port remains optimally positioned within the closed pocket region under varying load conditions.
3Reliability
If the economizer pressure does not match the compression chamber pressure, then working fluid may flow back to the economizer or pressure drops occur, reducing efficiency
Solution Approach 1:
By adjusting the injection port position parameter along the compression path, the system matches the local pressure in the closed pocket with the economizer pressure. This pressure matching prevents working fluid backflow to the economizer and avoids pressure drops, thereby maintaining system efficiency and reliability.
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 allows the economizer to maintain efficiency even when the compressor is unloaded, optimizing energy use and system performance by adjusting the injection position based on working conditions, thereby maximizing the capacity increase benefit of the economizer.
Implementation Method 1
The economizer may perform a heat exchanging process with the working fluid from the condenser or other components in the fluid circuit
Implementation Method 2
The economizer circuit injects subcooled vapor into this pocket, incrementally increasing the capacity output of that pocket
Data Source
AI summary
A compressor includes a bore, a rotor disposed within the bore, a compressor inlet, a compressor outlet and a compression chamber defined between the bore and the rotor. A volume of the compression chamber gradually reduces from the compressor inlet to the compressor outlet. An economizer is configured to fluidically connect to the compression chamber. The economizer is configured to inject a working fluid into the compression chamber at an injection position. The injection position is changeable according to a working condition of the compressor.