Analysis of Turbine Pressure, Feed Water Temperature and Condenser Back pressure on Performance of Power Generation System for Lead-based Reactor

count: [2022-11-03] [Close]

  1.  Greenhouse-gas emissions can be controlled by nuclear power plants
  2.  Development of the thermodynamic model, optimize the parameters and validation of the result with heat rate of the plant
  3.  Outcomes of this research can be used to instruct the power generation system control and operation.
The nuclear power plants are playing an important role to mitigate the energy demands and to safe environment from Carbon dioxide (CO2) emissions. Lead-based reactors have high core outlet temperature and have the potential to achieve high performance of power generation system. In this paper, a reference scheme with two reheater has been chosen for lead-based reactor with 400 MWth to improve the thermal performance of the system based on optimization of inlet parameters to overcome and meet the energy demands. The influence of turbine pressure, feed water temperature and condenser back pressure have been analyzed to improve the performance of lead-based power reactor.
Fig.1 Schematic of PGS at 22 MPa Note: P (MPa), T (oC) , m (kg/s)

 

The engineering equation solver software has been used for the thermodynamic calculation of the power plant. In this work, different inlet pressures of the turbine ranges from subcritical to supercritical cases (e.g. 18-22 MPa), influence of Feed Water Temperature (FWT) ranges from 335-356 oC at different pressures and condenser back pressure ranges from 0.004-0.015 MPa have been analyzed to evaluate the thermal performance and optimum value of the turbine inlet pressure, FWT and condenser back pressure. The schematic of PGS at 22 MPa with all parameters is shown in Fig. 1.


  • Total power generated by the turbine = 182.97MW;
  • Power required to pump the fluid after condenser and deaerator= 4.29 MW;
  • Total power=Thermal efficiency of the plant %.

 

The basic concept and schematic design of the PGS at 20 and 22 MPa turbine pressures is same as at 18 MPa. But, the major difference is on the bases of parametric distributions of temperature, pressure, and working fluid mass flow rate at the inlet and outlet of each component of system.

The maximum efficiency and power generated by plant can be achieved up to 49.45% and 201.9 MW at 22 MPa pressure and 356 oC FWT. The steam pressure and FWT cannot be increased from 22 MPa and 356 oC due to corrosive behavior of the lead and phase change behavior of the feed water as shown in figure 2 --(a) Effect of inlet temperature on efficiency  (b) Effect of inlet temperature on net power.

 
Fig.2 Effect of feed water inlet temperature on efficiency and net power

The capacity of the plant can be increased about 35.7 MW, 36.6 MW and 37.7 MW for every 20% increase in the load at 18 MPa, 20 MPa and 22 MPa, respectively. Unit cost of the plant decreased at full load because overall performance of the plant increased as the load increased as shown in figure 3 --(a) Variation in net power with partial load -  (b) Variation in efficiency with partial load

 

 Fig.3 Effect of load variation on net power and efficiency


The performance of the PGS decreased with the increase of condenser back pressure from 0.004 MPa to 0.015 MPa. The maximum performance of system was 45.28% at 0.004 MPa condenser back pressure as in figure 4. The maximum heat rate of the plant was 2361.36 kJ/MW at 0.015 MPa and the minimum heat rate of the plant was 2157.25 kJ/MW at 0.004 MPa condenser back pressure, respectively. The total heat rate of the plant increased 1.50% by increasing 0.0022 MPa each time therefore efficiency of the plant increased. Hence, it is concluded that current analysis for the optimization of condenser back pressure on the bases of thermodynamic analysis is correct because at 0.004 MPa performance of the system was 45.28% and heat rate was 2157.25 kJ/MW as in Fig 5.


The CO2 emissions to environment can be controlled by increasing the performance of the lead-based power reactor. This work can be used for the analysis and optimization of a power plant based on heavy metal cooled reactor concept as in figure 6.

 

 

Reported by Muhammad Salman Khan