Multi-Stage Compressor Motor Switching for Three-Capacity Operation
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Solution Overview
Problem
Conventional HVAC systems with two-stage compressors are limited to two run capacities, which decreases overall efficiency and SEER/EER ratings, while variable capacity compressors offer higher efficiency but at a higher initial cost.
Innovation Solution
A control system that operates a two-stage compressor at three capacities by using a control module to switch the motor connections and solenoid valve settings based on demand, allowing for high, mid, and low capacity modes, utilizing line voltage and a drive for motor speed control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a two-stage compressor is used, then the initial cost is lower, but the overall efficiency and SEER/EER ratings decrease due to limited run capacities
Solution Approach 1:
The patent applies dynamics by enabling the two-stage compressor to operate at three different capacities (high, mid, and low) rather than being fixed at two stages. The control module dynamically switches between different motor winding connections (main winding to high voltage line, auxiliary winding to capacitor or low voltage line) and solenoid valve positions to achieve variable capacity operation, allowing the system to adapt to different cooling demands and improve overall energy efficiency while maintaining lower initial costs compared to variable capacity compressors
2Ease of manufacture
If a two-stage compressor is used, then the initial cost is lower, but the SEER and EER ratings decrease due to limited run capacities
Solution Approach 1:
The control module dynamically adjusts the compressor operation between three capacities by switching motor connections and solenoid valve settings based on cooling demand, enabling the system to achieve higher SEER and EER ratings through optimized part-load performance while maintaining the cost advantages of a two-stage compressor design
3Manufacturing precision
If variable capacity compressor is used, then the SEER and EER ratings improve, but the initial cost increases
Solution Approach 1:
The patent segments the variable capacity functionality into discrete three-stage operation levels (high, mid, low) controlled by switching between different motor winding configurations and solenoid valve positions. This segmentation allows the system to achieve variable capacity performance and improved SEER/EER ratings while using a simpler two-stage compressor hardware design, reducing the initial cost compared to full variable capacity compressors
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 provides energy efficiency benefits, compliance with efficiency regulations, and reduced operating costs, offering a balance between higher efficiency and lower cost compared to variable capacity compressors.
Implementation Method 1
a solenoid valve configured to selectively either operate in (a) a first capacity or (b) a second capacity
Implementation Method 2
a drive configured to control a speed of the motor
Implementation Method 3
a third switch configured to selectively connect the auxiliary winding to either (a) a capacitor or (b) a third output of the drive
Data Source
AI summary
A system for controlling a capacity of a compressor includes a motor of the compressor including a main winding connected at a connection point to an auxiliary winding and a drive configured to control a speed of the motor. The system includes a first switch configured to selectively connect the main winding to either a first line voltage or a first output of the drive, a second switch configured to selectively connect the connection point to either a second line voltage or a second output of the drive, and a third switch configured to selectively connect the auxiliary winding to either a capacitor or a third output of the drive. The system includes a solenoid valve configured to selectively either operate in a first capacity or a second capacity. The system includes a control module configured to control the drive, the first switch, the second switch, and the third switch.