THE UNIVERSITY OF MICHIGAN
Department of Mechanical Engineering
ME 235 Thermodynamics I / Winter 2014 / Section 002
Due date: Apr. 10 2014
7.16 The shaft work in a pump to increase the pressure is small compared to the shaft work in an air
compressor for the same pressure increase. Why?
7.19 In a heat pump that uses R-134a as the working fluid, the R-134a enters the compressor at 150 kPa,
−10°C and the R-134a is compressed in an adiabatic process to 1 MPa using 4 kW of power input. Find
the mass flow rate it can provide assuming the process is reversible.
7.38 A small turbine delivers 1.5 MW and is supplied with steam at 700°C, 2 MPa. The exhaust passes
through a heat exchanger where the pressure is 10 kPa and exits as saturated liquid. The turbine is
reversible and adiabatic. Find the specific turbine work, and the heat transfer in the heat exchanger.
7.41 A turbo charger boosts the inlet air pressure to an automobile engine. It consists of an exhaust gas
driven turbine directly connected to an air compressor, as shown in Fig. P7.41. For a certain engine load
the conditions are given in the figure. Assume that both the turbine and the compressor are reversible and
adiabatic having also the same mass flow rate. Calculate the turbine exit temperature and power output.
Find also the compressor exit pressure and temperature.
Fig. P7.41 7.44 A hea