Question

Question 23

A closed empty bottle with a volume of 0.01 m3 stands in an atmospheric environment at 90 kPa pressure and 27 ^oC temperature. A valve on the neck of the bottle is opened and atmospheric air is allowed to enter the bottle. As a result of the air trapped inside the bottle and the heat transfer of the bottle wall with the atmosphere, the thermal balance is achieved with the atmosphere. Throughout this process, the valve is left open until the air trapped in the bottle reaches a mechanical balance with the atmosphere. Accordingly, find the net heat transfer from the bottle wall.

Answer 1

Air is getting into the bottle, we can assume air as an ideal gas, And there is no work done. So we can apply the mass and energy balance.

To find the heat transfer we will need the enthalpy and internal energy of air at 300k. From table A-17. Please find the attached solution.