Component coolers, steam surface condensers, feedwater heaters, and steam generators in PWR nuclear plants are examples of which heat exchanger type?

Component coolers, steam surface condensers, feedwater heaters, and steam generators in PWR nuclear plants are examples of which heat exchanger type?

• A. Indirect Contact
• B. Direct Contact
• C. Plate and Frame
• D. Crossflow

Answer: (A)

The key idea is heat transfer without mixing the two fluids. These plant components use indirect contact heat exchangers, where heat moves through a solid barrier (usually a metal wall or tube wall) that keeps the primary fluid (steam or hot coolant) separate from the secondary fluid (cooling water or feedwater). In a steam surface condenser, turbine exhaust steam gives up heat to cooling water, but the steam never mixes with the cooling water—it's condensed on the outside of tubes and the condensate is kept separate. Feedwater heaters heat feedwater by passing it on one side of a heat exchanger surface while steam sits on the other side, again with a barrier between them. Steam generators in a PWR transfer heat from the reactor coolant to the secondary water through tube walls inside the generator, so the fluids never mix. Component coolers follow the same principle. This separation by a barrier is what defines indirect contact heat exchangers. Direct contact would involve fluids merging, which is not how these particular components operate.

The key idea is heat transfer without mixing the two fluids. These plant components use indirect contact heat exchangers, where heat moves through a solid barrier (usually a metal wall or tube wall) that keeps the primary fluid (steam or hot coolant) separate from the secondary fluid (cooling water or feedwater). In a steam surface condenser, turbine exhaust steam gives up heat to cooling water, but the steam never mixes with the cooling water—it's condensed on the outside of tubes and the condensate is kept separate. Feedwater heaters heat feedwater by passing it on one side of a heat exchanger surface while steam sits on the other side, again with a barrier between them. Steam generators in a PWR transfer heat from the reactor coolant to the secondary water through tube walls inside the generator, so the fluids never mix. Component coolers follow the same principle. This separation by a barrier is what defines indirect contact heat exchangers. Direct contact would involve fluids merging, which is not how these particular components operate.