How do heat exchangers primarily transfer heat between fluids onboard the ship?

How do heat exchangers primarily transfer heat between fluids onboard the ship?

• A. Convection
• B. Conduction
• C. Radiation
• D. Evaporation

Answer: (A)

Heat exchangers move energy between fluids mainly through convection in the fluids as they flow past the exchanger surfaces. The hot fluid carries heat to the surface by its motion and turbulence (convection to the wall), where the energy then crosses the separating wall by conduction to the colder side. The cold fluid then picks up that energy and carries it away by convection on its side. So while conduction through the wall is essential for the actual transfer from one side to the other, the rate at which heat is transferred between the fluids is governed by the convective transport in each fluid to and from the boundary. Radiative transfer and evaporation aren’t the primary mechanisms in this typical setup, and conduction alone wouldn’t account for transferring heat from one moving fluid to another without the convective flow delivering the energy to the surface.

Heat exchangers move energy between fluids mainly through convection in the fluids as they flow past the exchanger surfaces. The hot fluid carries heat to the surface by its motion and turbulence (convection to the wall), where the energy then crosses the separating wall by conduction to the colder side. The cold fluid then picks up that energy and carries it away by convection on its side. So while conduction through the wall is essential for the actual transfer from one side to the other, the rate at which heat is transferred between the fluids is governed by the convective transport in each fluid to and from the boundary. Radiative transfer and evaporation aren’t the primary mechanisms in this typical setup, and conduction alone wouldn’t account for transferring heat from one moving fluid to another without the convective flow delivering the energy to the surface.