Question 1: Conservation of mass

Steam is pumped into a tank, where it condenses and leaves as a liquid. The data at the entrance and exit of the tank are shown in the figure to the right. Determine the mass flow rate entering and exiting the tank, as well as the rate of change of the total mass within the tank, all in kg/s.

Question 2: Compressor + Heat Exchanger

Steady-state operating data for a compressor and heat exchanger are provided in the figure below. The working fluid in the compressor in Nitrogen, while the separate cooling loop in the heat exchanger is Helium as shown. Modeling the Nitrogen as an ideal gas, and the Helium as an ideal gas with k = 1.67, determine the mass flow rate of the helium. Assume stray heat transfer, kinetic and potential energy effects are negligible. Determine the mass flow rate of the Helium in kg/s. )

Question 3: System Analysis

Separate streams of steam and air flow through the turbine and heat exchanger arrangement shown to the right. Steady-state operating conditions are as shown. Heat transfer to the surroundings, kinetic energy and potential energy effects can all be neglected. Determine (a) T3 in K and (b) the power output of the second turbine in kW.

Question 4 - Transient Analysis

A rigid copper tank, initially containing 1 m3 of air at 295K, 5 bar, is connected by a valve to a large supply line carrying air at 295K, 15 bar. The valve is opened only as long as required to fill the tank with air to a pressure of 15 bar, at which point the air in the tank is at 310K. The copper tank, which has a mass of 20 kg, is at the same temperature as the air in the tank, both initially and finally. The specific heat of the copper is c = 0.385 kJ/kg-K. Assuming ideal gas behavior for the air, determine (a) the initial and final mass of air within the tank, each in kg, and (b) the heat transfer to the surroundings from the tank and its contents, in kJ, ignoring kinetic and potential energy effects.