In a baffled shell and tube heat exchanger, what flows through the tubes?

In a baffled shell and tube heat exchanger, the correct answer is ammonia refrigerant. This type of heat exchanger is typically used in industrial refrigeration applications where ammonia serves as the refrigerant due to its efficient thermodynamic properties.

In this context, ammonia is circulated through the tubes of the heat exchanger to absorb heat from a secondary fluid. The design of baffled shell and tube heat exchangers allows for improved heat transfer efficiency by directing the flow of the secondary fluid around the tubes multiple times, increasing the surface area for heat exchange.

Using ammonia as a refrigerant is particularly advantageous because it has a high latent heat of vaporization, which makes it very effective for cooling purposes. The other options refer to fluids that could be part of a refrigeration system but are not typically the primary fluid flowing through the tubes in this specific type of heat exchanger.

For instance, while water might be used in some heat exchangers, it generally does not flow through the tubes in a system designed for ammonia refrigeration. Similarly, refrigerant from the evaporator is often utilized elsewhere in the refrigeration cycle and not directly through the heat exchanger tubes, and compressor oil is usually circulated in a different part of the system entirely, to lubricate the compressor rather than facilitate heat