What is the role of vacuum pumps in a condenser system?

Vacuum pumps play a crucial role in a condenser system by effectively removing air and non-condensable gases from the system. The presence of air and these gases can significantly impede the efficiency of the heat exchange process within the condenser. When air is allowed to remain in the system, it can create an insulating barrier that prevents proper thermal transfer between the steam and the cooling medium. This reduces the overall efficiency of the heat exchanger, making it harder to condense the steam back into water.

By utilizing vacuum pumps, the condenser can maintain a lower pressure environment, which not only promotes more efficient condensation of steam but also enhances the overall thermal performance of the system. The removal of non-condensable gases lowers the saturation temperature of the steam, allowing it to condense more rapidly and efficiently, thus improving the operation of the condenser and the entire thermal system.

The other options do not accurately describe the primary purpose of vacuum pumps in this context. For instance, increasing steam pressure, circulating condensed water, or preventing thermal shock are functions typically outside the scope of what vacuum pumps are designed to accomplish in a condenser system. Therefore, the function of removing air and gases to boost efficiency is the essential role of vacuum pumps in this setup.