In certain instances, there are problems when the state variables that is not temperature and pressure. Consider a throttling valve. In this case, a mixture of liquid and vapor enters a valve at 3MPa and leaves at 10KPa and 500C. Assume that the valve is adiabatic. Also, you are not given any information about velocities, so you need to make an assumption here.
a) What thermodynamics property is equal at the inlet and outlet of the valve?
b) What is the value of this property at the outlet?
c) What is the quality of the steam at the inlet?
d) Suppose that the areas of the pipes upstream and downstream of the valve are the same. Discuss how good the assumption is that the kinetic energy change can be neglected