Variable Capacity Compressor Control to Reduce Solenoid Overheating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing compressors face performance and durability issues due to solenoid overheating, especially under conditions like low-side faults or locked rotor conditions, which can lead to damage when modulating capacity between reduced and full-capacity modes.
Innovation Solution
A control system that monitors compressor parameters and uses a triac-based control system to modulate the compressor between reduced and full-capacity modes by selectively supplying reduced AC voltage to the solenoid, reducing its operating temperature and preventing overheating, and includes a compressor protection and control system to manage faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the solenoid is disposed within the hermetic shell of the scroll compressor to enable capacity modulation, then the compressor can modulate between reduced-capacity mode and full-capacity mode, but the solenoid experiences temperature rise due to supplied power and compressor operation, adversely affecting its performance and durability
Solution Approach 1:
The solenoid is extracted from the hermetic shell and relocated to an external position. The control system selectively supplies power to the solenoid to toggle the compressor between reduced-capacity mode and full-capacity mode, while the solenoid remains outside the hermetic shell to avoid exposure to high temperatures and refrigerant, thereby preventing overheating and improving durability
2Productivity
If the solenoid operates under increased temperature conditions due to power supplied and lack of refrigerant circulation, then capacity modulation is achieved, but the performance and durability of the solenoid are adversely affected
Solution Approach 1:
The solenoid is removed from the high-temperature environment inside the hermetic shell and positioned externally. This extraction allows the solenoid to operate in a cooler environment while still enabling capacity modulation through selective power supply, thereby maintaining productivity while improving reliability
Solution Approach 2:
The control system acts as an intermediary between the power source and the solenoid, selectively supplying power only when needed for capacity modulation. This controlled power supply reduces unnecessary heating of the solenoid while maintaining the required modulation functionality, thus preserving both productivity and reliability
3Reliability
If the compressor operates under low-side fault conditions or locked rotor conditions without refrigerant circulation, then fault conditions are detected, but the solenoid may overheat if operated, causing damage to the solenoid and/or compressor
Solution Approach 1:
The control system performs preliminary assessment of compressor operating conditions before activating the solenoid. By detecting fault conditions such as low-side faults or locked rotor conditions where refrigerant is not circulated, the control system prevents solenoid operation that would cause overheating, thereby eliminating the harmful effect before it occurs
Solution Approach 2:
The control system serves as an intermediary protective layer between the solenoid and harmful operating conditions. It monitors compressor status and selectively enables or disables solenoid power supply based on whether refrigerant circulation is present, preventing solenoid overheating and damage while maintaining fault detection reliability
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
The solution effectively protects the solenoid and compressor from overheating, extends operational life, and reduces complexity and cost by allowing efficient capacity modulation based on cooling demands, while also enabling the use of single-stage thermostats, thus enhancing overall system efficiency and reliability.
Implementation Method 1
the solenoid may be selectively supplied with power to toggle the compressor between the reduced-capacity mode and full-capacity mode and typically experiences a rise in temperature due to the supplied power
Implementation Method 2
An actuation device, such as a solenoid, may be used to modulate compressor capacity between the reduced-capacity mode and full-capacity mode by selectively providing leak paths between a non-orbiting scroll member and an orbiting scroll member of the compressor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system includes a power source, a compressor that operates in a reduced-capacity mode and a full-capacity mode, and an actuation assembly that modulates the compressor between the reduced-capacity mode and the full-capacity mode. A controller reduces the power source to a predetermined level prior to the power source being supplied to the actuation assembly for use by the actuation assembly in controlling the compressor between the reduced-capacity mode and the full-capacity mode.