Turbinas

Improve Steam Turbine Efficiency
Understand the factors that affect steam consumption
Steam are a major energy consumer. Optimising process operating conditions can considerably improve turbine water rate, which in turn will significantly reduce energy requirement. Various operating parameters affect condensing and back pressure turbine steam consumption and efficiency. Why Important The industrial sector is the largest energy consumer, accounting for about 30 % of total energy used. Fuel and energy prices are continuously rising. With the present trend of energy prices and scarcity of hydrocarbon resources lowering energy requirement is a top priority. Energy conservation benefits depend on the adopting minor or major modifications and using the latest technology. Energy conservation does not mean curtailing energy use at the cost of industrial and economic growth. In the large process industries, steam turbines are the main energy consumers. Savings achieved here will be significant, with a better return on investment than for most other equipment. Effect of operating conditions on steam turbines A condensing turbine system is shown in figure 1. Turbine exhaust operating below atmosphere, is condensed in a shell and tube exchanger called surface condenser. Condensate flows in the shell side of the condenser and steam is condensed by the cooling water. Vacuum in the surface condenser i.e. turbine exhaust vacuum is controlled/ maintained by vacuum ejector system of the surface condenser.

Turbine

Vent

Condenser CWR CWS Inter/after condenser Boiler CWR CWS

Motive Steam BFW Pump

Figure 1 : Diagrammatic details of a condensing type turbine Contd..2/-

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Turbines are designed for a particular operating conditions like steam inlet pressure, steam inlet temperature and turbine exhaust pressure/ exhaust vacuum, which affects the performance of the turbines in a significant way. Variations in these parameters affects the steam consumption in the