In industrial and scientific terms, a vacuum refers to a state where the pressure inside a vessel is lower than atmospheric pressure. The actual pressure inside the vessel is called the absolute pressure. LiBr absorption chillers and LiBr absorption heat pumps operate as sealed vessels, where the internal and external environments are isolated. During operation, the inside of the unit is maintained in a vacuum state to ensure optimal performance.

2. Why Vacuum Is Important for LiBr Absorption Chillers and LiBr Absorption Heat Pumps?

2.1 Ensuring the Performance of the LiBr Absorption Unit
The performance of the LiBr absorption chiller and heat pump is directly influenced by the vacuum level inside the unit. When the vacuum degree is high, the pressure in the evaporator remains low, which reduces the boiling point of the refrigerant water. This allows the refrigerant water to vaporize efficiently when sprayed onto the heat exchange tubes, absorbing heat from the chilled water inside. However, if the vacuum decays, the pressure increases, which raises the boiling point of the refrigerant water. As a result, the evaporation temperature increases, significantly reducing the ability to absorb heat and the overall efficiency of the unit. This is why we often say that "vacuum is the life of the LiBr absorption chiller and heat pump."

2.2 Preventing Corrosion Inside the Unit
LiBr absorption chillers and heat pumps are primarily made from metals such as steel or copper. LiBr solution, being a salt, is corrosive when exposed to oxygen. If air enters the unit, the oxygen reacts with the metal surface, causing oxidation, which accelerates wear and tear on the unit. By maintaining a vacuum inside the unit, the risk of oxygen exposure is minimized, preventing corrosion and extending the unit's lifespan.