Lubricant Blend Composition for Low-Refrigerant Solubility
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Solution Overview
Problem
In vapor compression systems, such as HVACR systems, the interaction between new refrigerants and lubricants can lead to changes in solubility and viscosity, requiring adjustments to maintain optimal lubrication and efficiency, which can result in increased power consumption, need for additional hardware, and restricted operating conditions, limiting system flexibility and sales.
Innovation Solution
A lubricant blend comprising a mixture of two or more lubricants, where the first lubricant has a higher viscosity than the second, balanced to achieve suitable miscibility and solubility with refrigerants, reducing refrigerant solubility and maintaining desired viscosity within the operating range of vapor compression systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a higher viscosity lubricant is selected to compensate for lubricant viscosity reduction due to higher refrigerant solubility, then bearing lubrication requirements are met, but power consumption increases and system efficiency decreases
Solution Approach 1:
The patent changes the chemical composition parameters of the lubricant by blending POE with alkylbenzene in specific ratios (15-85 wt% POE, 85-15 wt% alkylbenzene). This parameter change reduces refrigerant solubility in the lubricant, thereby reducing viscosity reduction during operation and maintaining adequate lubrication without requiring higher initial viscosity lubricants, thus avoiding increased power consumption
Solution Approach 2:
The patent creates a composite lubricant system by combining POE and alkylbenzene in a blended formulation. This composite approach leverages the complementary properties of both lubricants: POE provides good lubrication and refrigerant solubility, while alkylbenzene reduces overall refrigerant solubility and maintains viscosity stability, achieving both reliable lubrication and energy efficiency
2Reliability
If additional hardware (lubricant separator and/or lubricant heater) is added to the system to handle refrigerant-lubricant interactions, then lubrication requirements are maintained, but manufacturing cost increases and component reliability concerns arise
Solution Approach 1:
The patent extracts and eliminates the need for additional hardware components (lubricant separators and heaters) by incorporating the refrigerant solubility management function directly into the lubricant blend formulation. The blended POE-alkylbenzene lubricant inherently maintains proper viscosity and lubrication properties without requiring external separation or heating systems
Solution Approach 2:
The lubricant blend performs self-regulation of its refrigerant solubility characteristics through its blended composition. The alkylbenzene component naturally limits refrigerant dissolution, allowing the system to maintain adequate lubrication properties autonomously without requiring external control systems or additional hardware interventions
3Reliability
If the system operating map is restricted due to refrigerant-lubricant interactions, then lubrication requirements are satisfied, but product sales are limited due to inability to operate under customer-specified conditions
Solution Approach 1:
The patent modifies the lubricant's chemical composition parameters to reduce refrigerant solubility, which stabilizes viscosity across a broader range of operating conditions. This parameter change enables the system to maintain adequate lubrication throughout an expanded operating map, allowing operation under diverse customer-specified conditions without restriction
Solution Approach 2:
The blended lubricant formulation provides universal performance across multiple operating scenarios by inherently managing refrigerant solubility effects. The POE-alkylbenzene blend maintains lubrication properties whether the system operates at high or low speeds, varying temperatures, or different load conditions, eliminating the need to restrict the operating map
Data Source
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AI summary
Compositions, methods, systems, and applications herein are directed to lubricant blends that balance solubility and viscosity of a refrigerant, where in some cases the lubricant blends herein help reduce solubility of a refrigerant. A lubricant blend includes a mixture of two or more different types of lubricants to reduce refrigerant solubility.