HVAC Compressor Unloader State Estimation for Coordinated Control
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Solution Overview
Problem
HVAC systems face challenges in efficiently controlling compressor capacity and energy input due to the variability of unloader states, which affects refrigerant intake and overall system performance.
Innovation Solution
The method involves estimating the unloader state of a compressor based on measurable parameters such as current draw, torque, and power, using association maps to derive control parameters like compressor capacity and mass flow rates, allowing for precise regulation of fan speed, expansion device orifice size, and compressor operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the unloader state is directly measured using a position sensor inside the compressor, then the control precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent uses an intermediary estimation approach where the unloader state is not measured directly but inferred through measurable parameters (current draw, torque, power) that correlate with unloader position. This intermediary method avoids installing sensors inside the compressor while maintaining sufficient control precision through mathematical relationships between electrical parameters and mechanical state.
Solution Approach 2:
The patent replaces the mechanical sensing approach (position sensors inside the compressor) with an electrical measurement approach. By measuring electrical parameters (current, torque, power) that are easily accessible and correlate with unloader state, the system substitutes complex mechanical sensing with simpler electrical measurements and computational estimation.
2Device complexity
If the unloader state is estimated using measurable parameters, then the device complexity is reduced, but the measurement precision may be affected
Solution Approach 1:
The patent implements feedback mechanisms where the estimated unloader state is continuously refined based on measured electrical parameters. The system uses the relationship between current draw, torque, power, and unloader position to create a feedback loop that improves estimation accuracy over time, allowing precise control without complex sensing hardware.
Solution Approach 2:
The patent utilizes changes in electrical parameters (current draw, torque, power) that occur with unloader position changes to infer the unloader state. By monitoring how these parameters vary with unloader movement, the system translates easily measurable electrical changes into accurate estimates of mechanical state without direct physical sensing.
3Use of energy by moving object
If the compressor capacity is controlled by adjusting the unloader position, then the energy efficiency is improved, but the control complexity increases
Solution Approach 1:
The patent enables the compressor control system to self-regulate by using its own electrical measurement capabilities to estimate unloader state and adjust capacity. The system serves itself by leveraging existing electrical sensors and computational resources to perform what would otherwise require additional complex sensing and control hardware, simplifying the overall control mechanism while maintaining energy efficiency.
Data Source
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AI summary
The embodiments disclosed herein are directed to systems and methods to control a HVAC system based on a state of an unloader of a compressor of the HVAC system.