Performance enhancement in coal fired thermal power plants. Part II: steam turbines

✍ Scribed by M. Siddhartha Bhatt; N. Rajkumar

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 187 KB
• Volume: 23
• Category: Article
• ISSN: 0363-907X
• DOI: 10.1002/(sici)1099-114x(199905)23:6<489::aid-er494>3.0.co;2-t

✦ Synopsis

This paper presents the results of the performance enhancement study on 22 coal "red thermal power stations of capacities 30}500 MW. The oldest units (30 MW) have served for 33 yr and the newer units (500 MW) have been in operation since 7 yr. The turbine e$ciencies are in the range 31)00}41)90% as compared to the design range of 34)80}43)97%. The isentropic e$ciencies are in the range 74)13}86)40% as compared to design values of 83)20}89)10%.

Considerable scope for e$ciency improvement through low cost solutions: operational optimization, capital overhaul, simple modi"cations, etc., exists for all classes of units. The e$ciencies can be restored to their design values.

The developments in turbines over the last quarter of this century which have led to improved isentropic and thermal e$ciencies must be adopted for existing units through retro"ts, upgrades and revamps. The turbine e$ciencies can be improved to 38)0% for 30 MW units and to 47% for 500 MW units. The maximum potential is for improvement in 210 and 500 MW units followed by 110 and 120 MW units. The potential for 30 and 62)5 MW units is rather limited because of their low capacity share, lack of interest in manufacturers to sell spares (because of the low volume of requirement) and large pay back periods for modernisation schemes.