Forced Convection of a Tube Bundle

Convection Film Coefficient of a Tube Bundle

When organizing heat exchange between the heat carrier and a group of pipes located in several rows, the heat transfer process becomes somewhat more complicated. In this case, heat transfer depends on the relative position of the pipes and the row in which a particular pipe is located. At that, correction factors are introduced in the calculation of the Nusselt number, taking into account the location of the pipes in the group:

ε_s = (S₂ / d)^-0.15 - at in-lined pipe arrangement;

ε_s = (S₁ / S₂)^0.167 - at staggered pipe arrangement.

As the first row of pipes is in undisturbed fluid flow, the heat transfer of the pipes of the first row is less than that of the subsequent ones. In this regard, to take into account the unevenness of heat transfer, coefficients are introduced for the first, second and subsequent rows of pipes:

ε₁ = 0.6 - for first row;

ε₂ = 0.9 - for second row at in-line arrangement;

ε₂ = 0.7 - for second row at staggered arrangement;

ε_i = 1 - for third and next rows.

When calculating the Nusselt number, the similarity constants also depend on the relative position of the pipes in a turbulent flow:

Nu_f = 0.56×Re_f^0.5×Pr^0.36 - at laminar flow;

Nu_f = 0.26×Re_f^0.65×Pr^0.33 - at in-lined pipe arrangement in turbulent flow;

Nu_f = 0.41×Re_f^0.6×Pr^0.33 - at staggered pipe arrangement in turbulent flow.

In this calculation, the process of heat transfer from a bundle of pipes of diameter D is considered. The pipes are in contact with a fluid flow with dynamic viscosity μ, density ρ, thermal conductivity λ and specific heat C_p. The flow crosses the pipes at an angle ψ with an average velocity W.

As a result of calculations, the average convective film coefficient α of pipe outer surfaces is determined. In addition, similarity criteria for a given design case are determined, including Reynolds number Re, Prandtl number Pr, Peclet number Pe and Nusselt number Nu.

For the calculation, the number of pipe rows z and the distances between the pipes in transverse S₁ and longitudinal S₂ directions should be specified.

AREA MOMENTS OF INERTIA

BEAM CALCULATORS

TORSION OF BARS

CIRCULAR FLAT PLATES

BUCKLING

ELASTIC CONTACT

IMPACT LOADS

NATURAL FREQUENCIES

PRESSURED SHELLS

FLUID DYNAMIC

COMPOSITES

SPRINGS

THREAD CONNECTIONS

SHAFT CONNECTIONS

BEARINGS

DRIVES

FATIGUE

HEAT TRANSFER

Convection Film Coefficient of a Tube Bundle

INITIAL DATA

RESULTS DATA

BASIC FORMULAS

INITIAL DATA

RESULTS DATA

FLUID PROPERTIES

Fluid properties at 20ºC (68 ºF)

Fluid properties at 40ºC (104 ºF)

Fluid properties at 60ºC (140 ºF)

Fluid properties at 80ºC (176 ºF)

OTHER CALCULATORS