Q7. A Primary superheater has a single pass, counter flow arrangement and operates at a steam pressure of 50 bar. It has 60 tubes each with a mean diameter of 60 mm.
The gas flows through the tubes with a velocity of 1.5 m/s and enters with a temperature of 600℃ and leaves with a temperature of 300℃.
Dry saturated steam enters the heater at the rate of 900 kg/hour.
(a) Calculate EACH of the following:
(i) The heat transferred from the gas top the steam; (3)
(ii) The log mean temperature difference;(5)
(iii) The length of an individual tube.(5)
(b) Sketch the heat exchanger temperature profile diagram. (3)
Note: the specific heat capacity of steam, Csteam= 2.07 kJ⁄(kg K)
The gas side heat transfer coefficient = 0.229 kW⁄(m2 K)
The steam side heat transfer coefficient = 0.2 kW⁄(m2 K)
the specific heat capacity of gas, CP = 1.11 kJ⁄(kg K)
the density of the gas = 1.136 kg⁄m3
Please buy a membership plan and login via our app to view answers.
Download our App
