Actual regenerative Rankine cycle

Assume that the surroundings are at 285 K, the kinetic and potential energy changes are negligible, and this is a steady-state process. 

In this actual regenerative Rankine cycle, the steam extracted from the turbine heats the water from the condenser, and the water is pumped to the boiler. Sometimes, this occurs in several stages. The condensate from the feed heaters is throttled to the next heater at lower pressure. The condensate of the final heater is flashed into the condenser 

Because this is an isentropic process S5 = S6s = S7s, and we estimate the quality of the discharged wet steam at states 6s and 7s  

The fraction of steam extracted is estimated from the energy balance m6H6 + m2H2 = m3H3. In terms of the mass fraction z = m6/m3, we have zH6 + (1 -z) H2=H3. 

The turbine work output based on 1 kg/s working fluid is  

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Figure 4.22. (a) Schematic of actual regenerative Rankine cycle and (b) T-S diagram. 

Table 4.4a State properties of the actual regenerative Rankine cycle in Example 4.16...

A steam power plant is using an actual regenerative Rankine cycle. Steam enters the high-pressure turbine at ll,000kPa and 773.15K, and the condenser operates at lOkPa. The steam is extracted from the turbine at 475 kPa to heat the water in an open heater. The water is a saturated liquid after leaving the water heater. The work output of the turbine is 90 MW. The pump efficiency is 95% and the turbine efficiency is 75%. Determine the work loss at each unit if the surroundings are at 290 K. 

A steam power plant is using an actual regenerative Rankine cycle shown below. 

The table below shows the distribution of exergy losses in actual regenerative Rankine cycle. 

Table 4.4a shows the state properties of the actual reheat regenerative Rankine cycle. 

Table 4.6a shows the state properties of the actual reheat regenerative Rankine cycle. The turbine work output based on m — I kg/s working fluids ... 

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