Chapter 8, Problem 8.102EP

A water cooler for drinking water should cool 25 L/h water from 18 C to 10 C while the water reservoirs also gains 60 W from heat transfer. Assume that a small refrigeration unit with a COP of 2.5 does the cooling. Find the power input to the unit.

Air at 200kPa, 30°C is contained in a cylinder behind a piston with initial volume of 0.1 m3. The inside pressure balance ambient pressure of 100 kPa plus an external imposed force that proportional to V05, Now heat is transfer to the system to final pressure of 225 kPa. Find the work done for this process. (8.65 kJ)

In a turbine, steam enters with an enthalpy of 1275 Btu/lb, and leaves with an enthalpy of 1115 Btu/lbm. The transferred heat is 13 Btu/ibm. Find the turbine work in hp where the steam flow rate is 5 lbm/sec?

Qu A heat engine operates between 1625 C and 27 C and receives 400 kJ of heat. The maximum efficiency of the heat engine is The maximum work produced in kJ is

Q.3 Find the increase in unavailable energy associated with transfer of 800kJ of heat from a constant temperature system at 600K to another constant temperature at 400K. The ambient temperature is 300K. A 150kJ В 182kJ C 200kJ D 220kJ

A 600 MW heat engine, wh cooled by water, the therm efficiency of engine is 57 (percent. Determine the heat reject in engine.

Suppose 400 kW of power potential is wasted during the process as a result of irreversibility. Let say the heat pump received heat at a rate of 1000 kJ/s from a heat source. The reversible power of the present process is found to be 800 kW. Find unavailable heat, which is rejected to the sink.

How reversible process differs from irreversible process?

A solar collector absorbed 40W/m2 heat from the atmosphere. This is equal to the convection brought by air for drying purpose. If the temperature of the air is 40C while the solar collector area's temperature is 80C and neglecting effect of radiation, find the convective heat transfer coefficient.