Question

Saturated water steam at 295 oc is used to heat a stream of methanol (molecular weight 32 g/mol) vapor in a heat exchanger. the methanol vapor is heated from 60 oc to 250 oc under constant pressure. the flow rate of the methanol is 4800 kg/min, and the water steam condenses and leaves the heat exchanger as liquid water at 90 oc and 1 atm.

(a) calculate the required flow rate of the entering water steam in m3/min.
(b) calculate the rate of heat transfer from the water to the methanol

Answer 1

To calculate the required flow rate of entering water steam and the rate of heat transfer from the water to the methanol, we can use the equations Q = m * Cp * (T f - Ti) and equate the heat transfer rates of the water steam and methanol.

Step-by-step explanation:

To calculate the required flow rate of the entering water steam in m3/min, we need to determine the mass flow rate of the water steam. We can use the equation Q = m * Cp * (T f - Ti), where Q is the heat transfer rate, m is the mass flow rate, Cp is the specific heat capacity, T f is the final temperature, and Ti is the initial temperature.

First, we need to find the heat transfer rate from the methanol using the equation Q = m * Cp * (T f - Ti). Given the mass flow rate of the methanol (4800 kg/min), the specific heat capacity of the methanol, and the initial and final temperatures, we can calculate the heat transfer rate.

Therefore, the required flow rate of the entering water steam can be calculated by equating the heat transfer rate of the water steam to the heat transfer rate of the methanol and solving for the mass flow rate of the water steam.