Compressor Volume Ratio Control Using Pressure-Actuated Piston
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Solution Overview
Problem
Existing compressor systems face limitations in controlling the volume ratio due to the finite number of piston positions and the added costs of using additional components like proportional valves, which restrict precise and cost-effective adjustment of the compression ratio in HVAC&R systems.
Innovation Solution
A volume ratio control system that employs a piston within a compressor chamber, coupled with a biasing device, which adjusts the piston's position based on pressure differentials between the low and high pressure sides, allowing for infinitely variable control of the volume ratio without the need for additional mechanical or electrical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stepwise control of piston positions is used to adjust volume ratio, then the compressor can maintain performance at target levels, but the control precision is limited due to finite number of positions
Solution Approach 1:
The patent replaces the traditional mechanical stepwise piston control system with a fluid pressure-based control mechanism. A control chamber receives fluid pressure from the discharge side of the compressor, which acts on a piston to adjust the volume ratio. This substitution eliminates the need for discrete mechanical positioners and enables continuous, precise adjustment of the piston position based on pressure differential, thereby improving control precision while simplifying the mechanical control structure.
2Ease of operation
If proportional valve and control devices are added to adjust piston position, then volume ratio control is improved, but system cost increases
Solution Approach 1:
The patent implements a self-regulating control mechanism where the discharge side fluid pressure automatically adjusts the piston position in response to system conditions. The control chamber is fluidly coupled to the discharge side, creating a feedback loop where pressure differential self-adjusts the volume ratio without requiring external proportional valves or complex control devices. This self-service approach improves ease of operation while eliminating additional costly components.
Solution Approach 2:
The patent makes the discharge side fluid pressure serve multiple functions: it both drives the compressor operation and simultaneously controls the volume ratio adjustment. The same fluid pressure that is generated by compressor operation is routed to the control chamber to regulate piston position, eliminating the need for separate control systems and reducing overall device complexity.
3Productivity
If compression ratio is adjusted to maintain operating parameters, then system performance is optimized, but additional components are required to control piston position
Solution Approach 1:
The patent establishes a feedback control loop where the discharge side pressure, which reflects system operating conditions, is continuously used to adjust the piston position. The control chamber receives fluid pressure from the discharge side, creating an automatic feedback mechanism that optimizes compression ratio and volume ratio based on real-time system performance, eliminating the need for separate sensors and control devices.
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
Enables precise and cost-effective control of the compressor's volume ratio, enhancing performance by passively adjusting the piston's position in response to pressure differentials, thereby reducing costs and improving operational efficiency.
Implementation Method 1
a biasing device disposed within the chamber, where the biasing device is configured to adjust a position of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor
Data Source
AI summary
A volume ratio control system for a compressor includes a chamber formed within a housing of the compressor, a piston disposed within the chamber, where the piston is configured to separate the chamber into at least a first portion fluidly coupled to a low pressure side of the compressor and a second portion fluidly coupled to a high pressure side of the compressor, and a biasing device disposed within the chamber, where the biasing device is configured to adjust a position of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor falling below a threshold value.