An oil is cooled to 100 0C in a parallel flow heat exchanger by transferring its heat to cooling water, that leaves the exchanger at 300C. However, it is now required that the oil must be cooled down to 75 0C by increasing the length of heat exchanger, while oil and water flow rates, their inlet temperatures and other dimensions of the exchanger keeping constant. The inlet temperatures of water and oil are 15 0C and 150 0C respectively.
If the original cooler was 1 metre long, determine
- outlet temperature of water long, determine
- length of the new cooler