System and method of controlling a variable-capacity compressor
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Solution Overview
Problem
Climate-control systems, such as heat-pump systems, face inefficiencies in energy usage due to fixed compressor capacities, which fail to adapt to varying demand and outdoor temperature conditions effectively.
Innovation Solution
A climate-control system with a variable-capacity compressor and a control module that switches between low-capacity and high-capacity modes based on demand signals, outdoor air temperature data, and compressor runtime, allowing for adaptive operation to optimize energy efficiency and comfort levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a fixed-capacity compressor is used, then the device complexity is reduced, but the energy efficiency deteriorates because the compressor cannot adapt to varying demand conditions
Solution Approach 1:
The compressor capacity is made dynamically adjustable through a control module that switches between multiple capacity modes (first capacity mode, second capacity mode, and third capacity mode) based on real-time demand signals and outdoor temperature conditions, allowing the system to adapt to varying operational requirements without increasing physical device complexity
Solution Approach 2:
The system changes the operational parameters of the compressor by switching between different capacity modes (low, medium, high capacity) depending on the demand signal and outdoor temperature, enabling energy-efficient operation across different loading conditions without requiring multiple physical compressors
2Speed
If the compressor operates in high-capacity mode continuously, then the cooling or heating speed is improved, but the energy usage increases
Solution Approach 1:
The control module dynamically adjusts compressor capacity in real-time based on demand signals and outdoor temperature, switching between first capacity mode (lower speed, lower energy) and second capacity mode (higher speed, higher energy) to match actual system needs, thereby achieving fast response when necessary while conserving energy during moderate conditions
Solution Approach 2:
The compressor operates in periodic cycles, alternating between different capacity modes based on accumulated runtime thresholds and demand conditions, allowing the system to achieve adequate cooling/heating speed while minimizing energy consumption through strategic use of high-capacity mode only when necessary
3Use of energy by moving object
If the compressor operates in low-capacity mode for extended periods, then the energy efficiency is improved, but the system responsiveness to high demand deteriorates
Solution Approach 1:
The control module provides dynamic responsiveness by monitoring demand signals and outdoor temperature in real-time, enabling rapid switching from first capacity mode to second capacity mode when high cooling or heating demand is detected, ensuring system productivity is maintained while preserving energy efficiency during normal operating conditions
Solution Approach 2:
The system uses outdoor temperature sensing to anticipate high-demand conditions before they occur, allowing the control module to proactively switch to higher capacity modes in advance, thereby maintaining system responsiveness without excessive energy consumption during actual peak demand periods
Data Source
AI summary
A working-fluid circuit may include an indoor heat exchanger, a variable-capacity compressor and a control module. The variable-capacity compressor pumps working fluid through the indoor heat exchanger. The control module may control the compressor and operate the compressor in one of a first capacity mode and a second capacity mode based on a demand signal, outdoor-air-temperature data and a compressor runtime.