Noncondensable

Noncondensable refers to gases that do not liquefy or solidify under specific conditions, particularly at temperatures and pressures typically encountered in condensation processes. In essence, these are gases that remain in their gaseous state when other substances around them are condensing.

The term is frequently used in thermodynamics and engineering, especially in contexts involving steam, refrigerants, or other working fluids. For example, in a steam power plant, noncondensable gases like air or nitrogen can accumulate in the condenser. Their presence is undesirable because they form an insulating layer on the condenser tubes, reducing heat transfer efficiency and increasing the backpressure on the turbine, which lowers the overall plant output.

Identifying and removing noncondensable gases is a critical aspect of maintaining the performance of many industrial systems. Techniques such as venting or using vacuum pumps are employed to purge these gases. The specific gases considered noncondensable depend entirely on the operating temperature and pressure of the system. A gas that is noncondensable in one system might be condensable in another with different operating parameters.