Refrigeration Plant Operator B Practice Test

What is the primary use of waste heat in lithium bromide absorption systems?

1. For heating water

2. To evaporate the water out of weak lithium bromide

3. To condense refrigerant

4. To enhance efficiency

The correct answer is: To evaporate the water out of weak lithium bromide

In lithium bromide absorption systems, the primary use of waste heat is to evaporate the water out of weak lithium bromide solution. In these systems, a concentrated lithium bromide solution absorbs water vapor from the environment or from inside the evaporation chamber. The addition of heat is essential to facilitate the evaporation process, allowing the water to separate from the weak solution. By supplying waste heat, the system can effectively drive the evaporative process, concentrating the lithium bromide salt, which in turn enhances the cycle of cooling. This process not only helps in maintaining an effective cooling output but also ensures that the solution can be reused, making the system more efficient overall. This use of waste heat plays a crucial role in the thermodynamic performance of the absorption cycle, and leveraging waste heat is a key factor in making lithium bromide absorption chillers more energy-efficient.