Reference no: EM13627112

A Rankine cycle is used to generate electricity, with a total plant capacity of 65 MW. Heat from the condenser is removed using an ordinary vapor-compression refrigeration cycle. A schematic of the process is shown below. The feedwater preheater is closed. That is, there is no mixing of streams 2 and 6 in the unit. In the condenser for the Rankine cycle, streams 4 and 9 are mixed together. Heat is transfered directly from the Rankine cycle condenser to the evaporator of the refrigeration cycle. The process has the following characteristics.

• The inlet to the first turbine is at 20 MPa and 650 C.
• Steam leaves the first turbine at 7 MPa and 479.8^oC .
• The input to the boiler is at 200^oC (stream 7).
• The efficiency of both turbines and the compressor is 85%.

• Steam leaves the second turbine at 0.1 MPa.

The refrigeration cycle uses propane as the working fluid.

In the refrigeration cycle the evaporator operates at 10^oC and the condenser operates at 50^oC.

Given this information, please answer the following questions:

1. Determine the flow rate of propane in the refrigeration cycle (kg/s).

2. Determine the total work input required to the compressor (kJ/s).

3. Determine the work output of the first turbine per kg of steam.

4. Determine the ratio m1/m2.