System and method of controlling a variable-capacity compressor
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Solution Overview
Problem
Existing climate-control systems, such as heat-pump systems, face inefficiencies in energy usage due to fixed compressor capacities, which fail to adapt effectively to varying outdoor temperatures and user comfort levels, leading to suboptimal heating and cooling performance.
Innovation Solution
A method for controlling a compressor to switch between low-capacity and high-capacity modes based on outdoor air temperature and user-selected comfort levels, using a control module that sets runtime thresholds to minimize energy usage while maintaining comfort, allowing the system to adapt dynamically between modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the compressor operates continuously in high-capacity mode to quickly meet cooling or heating demand, then the system responds faster to thermal load changes, but energy consumption increases significantly
Solution Approach 1:
The compressor capacity is made dynamic by switching between high-capacity and low-capacity modes based on runtime thresholds. The system transitions from static fixed-capacity operation to dynamic variable-capacity operation, allowing the compressor to adapt its output to actual thermal load conditions while maintaining fast response capability when needed.
Solution Approach 2:
The control system implements periodic switching between high-capacity and low-capacity modes based on accumulated runtime thresholds. After the compressor accumulates a certain runtime in high-capacity mode, it automatically switches to low-capacity mode, creating a periodic operation pattern that balances rapid response with energy conservation.
2Use of energy by moving object
If the compressor operates in low-capacity mode to reduce energy consumption, then energy efficiency improves, but the system takes longer to meet heating or cooling demand
Solution Approach 1:
The system dynamically adjusts compressor capacity based on accumulated runtime. When the compressor has been running in low-capacity mode for a predetermined period, the system automatically transitions to high-capacity mode to deliver the required heating or cooling output, thus dynamically balancing energy efficiency with productivity.
Solution Approach 2:
The control system preliminarily operates the compressor in low-capacity mode to minimize energy consumption during periods when full cooling or heating output is not immediately required. This preliminary low-capacity operation is maintained until runtime thresholds are met, at which point the system prepares to switch to high-capacity mode to meet demand.
3Device complexity
If fixed runtime thresholds are used for switching between compressor modes, then the control logic is simple, but the system cannot adapt to varying outdoor temperatures and user comfort levels
Solution Approach 1:
The runtime thresholds for switching between compressor modes are changed from fixed values to variable parameters that depend on outdoor temperature and user-selected comfort level. The control system adjusts these threshold parameters dynamically based on environmental conditions and user preferences, enabling the system to adapt to varying operating conditions while maintaining relatively simple control logic.
Data Source
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AI summary
A climate-control system may include a variable-capacity compressor unit and a control module controlling the compressor unit. The compressor unit may be operable in a first capacity mode and in a second capacity mode that is higher than the first capacity mode. The control module may be configured to switch the compressor unit among a shutdown state, the first capacity mode and the second capacity mode based on a demand signal and outdoor-air-temperature data.