Question

Carbon dioxide (CO2) gas is steadily pressurized and cooled by sending it sequentially through a compressor and then a heat exchanger. The CO2 enters the compressor at 275 °C, 101 kPa, and 195 m/s at a rate of 0.425 kmol/s and exits the isobaric heat exchanger at 185 °C, 205 kPa, and 85.0 m/s. Cooling water enters the heat exchanger at 5.75 kg/s, 5.00 °C and 125 kPa and exits as a saturated liquid at the same pressure. Assume the entire system is well-insulated and that changes in potential energy can be neglected. CO2 behaves ideally with Cp = 4.5R and MW = 44. Need full working.

Answer 1

We can see that here there is velocity as well as the temperature change and thus we can use the combination of the energy change due to the velocity change as well as the temperature and can add them to get the energy change of the CO2.

We can use the steam table to find the saturated temperature for water at 125 kPa
Only unknown in the problem is the flow rate of the water and thus that can be found by energy balance.
We can assume that the process is adiabatic and thus.
Heat lost by CO2 = heat gained by water.

I am attaching the picture of the solution.

Specfic heat of water is taken as 75 J/mole.K

hope this helps

Thanks