Performance assessment and leakage analysis of feed water pre-heaters in natural gas–fired steam power plants

摘要

The performance of feed water pre-heaters (FWH) at a steam power plant with a capacity of 200 MW is evaluated in this paper. The main objective of this study is to investigate the behavior of these FWHs in various cases. The effect of leakage of condensates on the condenser was also studied in detail. To do this, each FWH was studied separately and also in groups (LP, HP and both groups). While some of the results are exclusive to the studied power plant, others can be generalized to similar power plants. The results show that although LPH-1 and LPH-2 have the lowest exergy efficiency, they have the greatest effect on the efficiency of the cycle. Whereas HPH-6 and LPH-4 have the highest heat exchange (31.3 and 21.73 MW), LPH-2 and LPH-1 deliver the greatest positive effect on energy efficiency (0.81% and 0.61/0%). Moreover, the results show the particular importance of preventing any leakage of heater condensate. In the event of leakage along the route to the condensate of heaters, the most negative effect will be due to the HP heaters: 20 kg/s leakage in the HPHs line will cause an increase in CO2 production p.a. of roughly 10150 metric tons. Furthermore, energy efficiency and power produced will fall by 0.374% and 5.1 MW. In terms of the impact of leakages on the cooling tower, the study showed that LPH-1 and LPH-2 have the greatest effect. The effects of LP and HP FWHs on the energy efficiency of the cycle were 2.53% and 0.82%.