Question 3 (35 marks)
Three tubes channel a total mass flow of 10 kg/s of cool water (280 K) through a steam shell (400 K, saturation pressure). The steam is provided in excess and there is no change in temperature. The cool water is heated to 360 K, while the steam remains at 400 K throughout the shell.
(10 marks)
a) Determine the effectiveness of the heat exchanger.
(5 marks)
b) Determine the capacity ratio and interpret the value of the capacity ratio.
(10 marks)
c) Determine the log-mean temperature difference and use it to determine the overall heat transfer coefficient (UA).
(10 marks)
d) Calculate the number of transfer units from the overall heat transfer coefficient and compare with the number of transfer units calculated from the effectiveness. NTU relations for a heat exchanger.