Question

heat transfer project - i need help to see what direction you would take this problem in order to make the design.

Design a counter-flow, concentric-tube heat exchanger to use water forc al power station. The mass flow rate of the oil is given as 0.2 kg/s, and its inlet emperature is 90°C. The water is available at 20°C, but its temperature rise is restricted to 12.5°C of environmental concerns. The outer tube diameter must be less than 5 cm, and the inner ube diameter must be greater than 1.5 cm due to constraints arising from space and piping be iderations. The engine oil must be cooled to a temperature below 50°C. system if the length is restricted to 100 m. Fo kJ/kg. C, 8.55x10-*kg/m.s, and 0.613 W/m."C for water) teasible design, if the length of the heat exchanger must not exceed 200 m. Redesign the r simplification, take the fluids properties as constant. (Constant pressure specific heat, dynamic viscosity, and thermal conductivity as 2.1 kJ/kg.°C, 0.03 kg/m.s, and 0.15 W/m.°C for oil, and 4.179

Answer 1

Do Tho 50 eney cph Th-Tho 0.2x2100 (40-45 g.1 k Lo et ou letempau a otl less than 50,"take 45% tempo. atau (890 0 limited to 125% 18900 479 12.5 mW 18400 0 31-3% .

τ (90-313) -( 15-20 2%. he ho outleb tubes 4. muw Nu 116.8 Nu 518

2 For outer lube RPvD m) usslet mumlot be taken as 5A 0 0 2 800 Case length 100m L, Do may be Incse aged opto Sevm

o whtle keepin a Dunc 1698 (amina TL 18900 on