Chapter 9, Problem 9.34P

A thermal power plant operates such that the steam exits boiler at 4 MPa, 400C and the condenser pressure is 10 kPa. The efficiency of the turbine and pump is 85% and 90% respectively. a. Draw the plant PFD (Process Flow Disgram) and the process Ts diagram and calculate quality of steam discharge from the turbine as well as the plant's thermal efficiency. b. If the plant produces 300MW of net power, - What is the steam flowrates in kg/hr? - If the plant uses natural gas as a fuel, determine the flowrate of NG in MMSCMD. State the reference for your data. - If the plant uses coal as a fuel, determine the amount of coal required (tonne per annum). State the reference for your data and all your assumptions. c. How much power required by the pump in kW? Is this the real power required by the pump? Explain d. Find the heat rejected in the condenser and evaluate the thermal efficiency using this value. e. The heat rejected to surrounding is through a cooling water system from a nearby ocean.…

. In an absorption type refrigerator, the heat is supplied to NH3 generator by condensing steam at 200 kPa and 90% dry. The temperature in the refrigerator is to be maintained at -5 OC. Find the maximum COP possible. If the refrigeration load is 18 tons and actual COP is 70% of the maximum COP, find the mass of steam required per hour. Assume an atmospheric temperature of 37OC.

A small power plant produces 25 kg/s steam at 3 MPa, 600 degrees Celsius in the boiler. It cools the condenser with the ocean water coming in at 12 degrees Celsius and returning at 15 degrees Celsius so the condenser exit is at 45 degrees Celsius. Find the net power output and the required mass flow rate of ocean water.