The Reason Why Non-condensable Air is Generated During LiBr Absorption Unit Operation?
The Definition of Non-Condensable Air
In the context of LiBr absorption chillers, LiBr absorption heat pumps, and vacuum boilers, non-condensable air refers to air that cannot be condensed or absorbed by the LiBr solution. This includes air that enters the system from external sources or gases such as hydrogen, which may be generated due to corrosion inside the unit. Non-condensable air negatively impacts the performance of these systems by reducing the vacuum level, which in turn affects heat transfer efficiency and overall system operation. Proper management and removal of non-condensable air are essential for maintaining optimal system performance.
- The Source of Non-Condensable Air
- Leakage or Improper Operation
LiBr absorption units operate under high vacuum conditions, which makes them susceptible to air entering the system if there are leakage points or damage to the shell or heat exchanger tubes. Even with high-quality construction, it is difficult to maintain perfect air-tightness in the unit over time due to wear and tear from long-term operation. - Hydrogen Generated by Internal Corrosion
LiBr absorption units are typically made from steel or copper. The corrosion of metals by LiBr solution occurs primarily through electrochemical reactions. Under the influence of oxygen, the metals lose electrons, leading to the formation of hydroxides (e.g., Cu(OH)₂). The lost electrons then combine with hydrogen ions (H⁺) in the LiBr solution, producing non-condensable hydrogen gas (H₂).
- Leakage or Improper Operation
- How to Deal with Non-Condensable Air
To manage non-condensable air, Hope Deepblue’s LiBr absorption chillers and heat pumps are equipped with a vacuum pump and come standard with a dedicated air chamber to store any non-condensable air generated during operation. Additionally, optional devices and functions, such as solenoid vacuum valves and automatic start/stop vacuum systems, can be integrated into the units. These features help significantly reduce the need for manual purging, improving efficiency and reducing operational costs for customers.
Post time: Jan-12-2024
