How do you calculate the overall heat transfer coefficient of a heat exchanger?

Composition

= the overall heat transfer coefficient (W/(m2•K))
= the contact area for each fluid side (m2) (with and expressing either surface)
= the thermal conductivity of the material (W/(m·K))
= the individual convection heat transfer coefficient for each fluid (W/(m2•K))
= the wall thickness (m).

How is shell side heat transfer coefficient calculated?

Shell Side Heat Transfer Coefficients

Ds, the shell inside diameter.
fB, the fraction of the shell cross-section that makes up the baffle window.
Nbt, the number of tubes in the baffle window (usually approximated by fb*Ntubes)
PB, the baffle pitch (spacing)
pt, the tube pitch.
do, the tube outside diameter.

How does heat transfer coefficient increase tube side?

Segmental baffles are the most commonly used. They improve the heat transfer by enhancing fluid turbulence or local mixing on the shell side as a result of causing the shell side fluid to flow in a zigzag manner across the tube bundle. It also increases the pressure drop.

How do you calculate the overall heat transfer coefficient of an evaporator?

Some typical heat transfer resistances

static layer of air, 40 mm (1.57 in) : R = 0.18 m2K/W.
inside heat transfer resistance, horizontal current : R = 0.13 m2K/W.
outside heat transfer resistance, horizontal current : R = 0.04 m2K/W.
inside heat transfer resistance, heat current from down upwards : R = 0.10 m2K/W.

What affects the heat transfer coefficient?

The factors affecting overall heat transfer coefficient are : Physiochemical properties of fluids ( both cold and hot ) such a viscosity , density, specific heat, thermal conductivity. Geometry of the exchanger ( equivalent length and heat exchanging area ) Velocity of flowing fluids.

What is the unit of radiative heat transfer coefficient?

The factor hr is called the coefficient of radiant heat transfer from solid to solid and is expressed in W/m2-deg temperature difference between the enclosed and enclosing surfaces.

Does convective heat transfer depend on temperature?

The constant of proportionality is the heat transfer coefficient. The law applies when the coefficient is independent, or relatively independent, of the temperature difference between object and environment. In classical natural convective heat transfer, the heat transfer coefficient is dependent on the temperature.