Considering Other Vapor Cycle AspectsFigure P8.82 shows the schematic diagram of a cogener...

Considering Other Vapor Cycle Aspects

Figure P8.82 shows the schematic diagram of a cogeneration cycle. In the steam cycle, superheated vapor enters the turbine with a mass flow rate of 5 kg/s at 40 bar, 440°C and expands isentropically to 1.5 bar. Half of the flow is extracted at 1.5 bar and used for industrial process heating. The rest of the steam passes through a heat exchanger, which serves as the boiler of the Refrigerant 134a cycle and the condenser of the steam cycle. The condensate leaves the heat exchanger as saturated liquid at 1 bar, where it is combined with the return flow from the process, at 60°C and 1 bar, before being pumped isentropically to the steam generator pressure. The Refrigerant 134a cycle is an ideal Rankine cycle with refrigerant entering the turbine at 16 bar, 100°C and saturated liquid leaving the condenser at 9 bar. Determine, in kW,

(a) the rate of heat transfer to the working fluid passing through the steam generator of the steam cycle.

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(b) the net power output of the binary cycle.

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(c) the rate of heat transfer to the industrial process.

Fig.P8.82