.  Determine the overall heat transfer coefficient and flow rate required while using a heat exchanger , the water is enetered at 20◦C through the tubes of small single pass  and the water comes out with a temperature at 40◦C. 25 kg/min of steam condenses at 60◦C on the shel side ,the area of the exchanger is 12 m2. (The latent heat, hfg, is 2358.7 kJ/kg at 60◦C.)

QUESTION 9 As in the previous question, a concentric-tube, counter-flow heat exchanger, as shown below, is used to cool mercury [C, h = 1,370 J/kg - "C] flowing at a rate of 1.0 kg/s from 110°C to 70°C. 10 The cooling fluid is water entering the heat exchanger at a temperature of 30°C and flow rate of 0.2 kg/s. The overall heat transfer coefficient of the exchanger is U = 250 w/m² - °C. Water Mercury Calculate the required heat transfer area. O 7.75 m2 O 11.75 m2 O 4.75 m2 O None of these answers O 8.75 m2 Click Save and Submit to save and submit. Click Sare All Answers to save all answers. Save All Answers 人 100% G

3.36 Both C's in a parallel-flow heat exchanger are equal to 156 W/K, U 327 W/m²K and A = 2 m². The hot fluid enters at 140°C and leaves at 90°C. The cold fluid enters at 40°C. If both C's are halved, what will be the exit temperature of the hot fluid?

Below data was obtained from an experimental activity for a parallel pipe heat exchanger. Arrangement: counterflow (cold fluid in annular and hot fluid in tube). Mass flow rate: - Hot fluid: 1.03 kg/s - Cold fluid: 0.91 kg/s Temperatures: - Hot fluid inlet (Th.1): 80.5 +/- 10% °C - Hot fluid outlet (Th2): 64.0 +/- 10% °C - Cold fluid inlet (Te1): 20.0 +/- 10% °C - Cold fluid outlet (Tc2): 41.0 +/- 10% °C Assume cp constant and equal to 4.2 kJ/kg-K. 1. State assumptions (at least 9 unique ones) and include references. 2. What is the log mean temperature difference in °C? 3. What is the heat transfer rate on the cold side in kW? Heat added or lost on cold side? 4. What is the heat transfer rate on the hot side in kW? Heat added or lost on hot side? 5. What is the effectiveness of the heat exchanger for the given conditions? 6. Calculate the propagation of uncertaintv in kW for part 3 (heat transfer rate on the cold side) and part 4 (heat transfer rate on the hot side).