Refrigerant system with multiple load modes
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Solution Overview
Problem
Current refrigerant systems face inefficiencies and poor temperature control due to unit cycling and high refrigerant mass flow rates, and existing unloading methods like suction modulation valves are expensive and inefficient for capacity control.
Innovation Solution
A refrigerant system with a multi-stage compressor assembly, controlled by valves in the suction and bypass lines, allowing for selective regulation of refrigerant flow to achieve multiple capacity modes, optimizing energy efficiency and temperature control through controlled valve operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If unit cycling is used for system unloading, then the system can operate at multiple capacity modes, but temperature control accuracy deteriorates and energy efficiency decreases
Solution Approach 1:
The patent applies dynamics by using a continuously modulating suction modulation valve instead of discrete on/off cycling. The valve can be positioned at any degree of opening (0-100%), allowing the system to dynamically adjust refrigerant flow and achieve any capacity level between full load and complete unload, thereby maintaining tight temperature control while providing versatile capacity control.
Solution Approach 2:
The patent changes the parameter of refrigerant mass flow rate from discrete steps (on/off) to continuous variation through valve modulation. By controlling the valve position, the system can precisely adjust the amount of refrigerant entering the compressor, enabling smooth transitions between capacity modes and accurate temperature maintenance without the harsh on/off cycling.
2Adaptability or versatility
If unit cycling is used for system unloading, then the system can operate at multiple capacity modes, but energy efficiency deteriorates due to cycling losses
Solution Approach 1:
The patent implements continuity of useful action by keeping the compressor running continuously at full speed while using the suction modulation valve to control capacity. This eliminates the harmful start-stop cycling losses entirely, as the compressor operates continuously with smooth, continuous capacity adjustment through valve modulation, maintaining energy efficiency across all capacity modes.
3Adaptability or versatility
If a suction modulation valve is used for system unloading, then capacity control is achieved, but system cost increases and energy efficiency deteriorates due to flow throttling losses
Solution Approach 1:
The patent uses the suction modulation valve as an intermediary device positioned in the suction line before the compressor. The valve modulates the amount of refrigerant reaching the compressor inlet, allowing precise capacity control without requiring the compressor itself to modulate speed or the discharge valve to throttle. This intermediary approach enables efficient capacity control by regulating flow at the most effective point in the system.
Data Source
AI summary
A refrigerant system capable of operating at multiple capacity modes includes an evaporator, a multi-stage compressor assembly, a first fluid flow path, a second fluid flow path, a first valve, and a second valve. The multi-stage compressor assembly has a first stage and a second stage. The first fluid flow path extends from the evaporator to the first stage of the multi-stage compressor assembly. The second fluid flow path connects to the first fluid flow path and to the multi-stage compressor assembly between the first stage and the second stage.