130,000 kg/hr of crude oil is to be heated from 20 to a higher temperature by heat exchange with a hot refined hydrocarbon that is available at 152 C. To accomplish this, a 1-2 tube and shell exchanger (1 shell side pass, 2 tube side passes) will be used. The exchanger is TEMA Type AES. The tubes are steel, in. OD, BWG 14, 12 ft long, and configured on a 1 in. triangular pitch. Average properties for the fluids are provided below.

Table 1. Fluid Properties

	HC Distillate	Crude
Cp (J/g-C)	2.2	1.99
(cP)	5.2	2.9
(kg/m3)	867	825
k (W/m-C)	0.119	0.137

Tube Steel k = 45.0 W/m-C

For this exchanger and the performance specs listed below, estimate the number of tubes needed to provide sufficient total heat transfer area (based on tube outside area). Round up and give answer with zero decimal places (i.e. no fractional tubes!).

Duty (Q) = 2,458 kW

Corrected LMTD = 86 C

U_o = 260 W/m²C