Phase-Change Compressor Cover for Refrigerant Migration Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Refrigerant migration to the compressor in HVAC systems can cause damage and reduce compressor lifespan due to rapid vaporization when the system is restarted, and current solutions for keeping the compressor warm, such as resistance heaters and motor winding heating, are energy inefficient.
Innovation Solution
A phase change compressor cover comprising an insulative layer and a phase change layer that absorbs heat during compressor operation and slowly dissipates it back to the compressor when it is not operating, using a phase change material with a high heat of fusion to maintain compressor temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resistance heaters or motor winding heating is used to keep the compressor warm, then refrigerant migration is minimized, but energy consumption increases
Solution Approach 1:
The phase change material is pre-charged into the compressor shell cavity during manufacturing, positioned to surround the compressor motor. This preliminary action ensures the thermal protection mechanism is already in place before the compressor operates, eliminating the need for auxiliary heating systems and reducing energy consumption while maintaining reliability
Solution Approach 2:
The phase change material absorbs heat from the compressor motor during operation and releases it during shutdown cycles automatically, without requiring external control or additional energy input. This self-regulating thermal management system protects the compressor from refrigerant migration while being energy-independent
2Reliability
If the compressor is kept warm using auxiliary heating, then refrigerant migration is reduced, but device complexity increases
Solution Approach 1:
The heating function is extracted from the main compressor assembly and replaced by a passive phase change material layer charged into the compressor shell cavity. This extraction eliminates complex heating controls, sensors, and power management systems while maintaining the essential function of preventing refrigerant migration through simple thermal diffusion
Solution Approach 2:
The thermal properties of the compressor environment are modified by introducing phase change material with specific melting and freezing points tailored to compressor operating temperatures. This parameter change enables automatic thermal regulation through phase transitions, simplifying the system while maintaining reliable protection against refrigerant migration
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 phase change compressor cover efficiently maintains compressor temperature without auxiliary heating, reducing energy consumption and extending compressor lifespan by continuously dissipating heat for an extended period, thus minimizing refrigerant migration and the need for auxiliary heat sources.
Implementation Method 1
A compressor cover is disclosed as comprising: a first layer comprising a first layer outer surface, a first layer inner surface, and a first layer base; and a second layer comprising a second layer outer wall comprising a second layer outer wall outer surface and a second layer outer wall inner surface, a second layer inner wall comprising a second layer inner wall outer surface and a second layer inner wall inner surface, and a second layer base comprising a second layer base outer surface and a second layer base inner surface, wherein the second layer outer wall inner surface, the second layer inner wall outer surface, and the second layer base inner surface form a second layer cavity.
Implementation Method 2
using a phase change material with a high heat of fusion to maintain compressor temperature
Implementation Method 3
operating the compressor; absorbing heat discharged as a result of operating the compressor into the compressor cover; and discharging heat from the compressor cover to the compressor when the compressor is not operating
Data Source
AI summary
A phase change compressor cover may include a first layer configured to provide sound attenuation from undesirable noise produced as a result of operating a compressor and/or thermal isolation of the compressor and a second layer comprising a cavity filled with a phase change material that is configured to absorb heat discharged as a result of operating the compressor and subsequently discharge the absorbed heat onto the compressor in response to discontinuing operation of the compressor to keep the compressor warm and prevent refrigerant migration to the compressor. The phase change compressor cover may be used to substantially envelope the compressor in a heat pump heating, ventilation, and/or air conditioning (HVAC) system.