3000 4000 5000 6000 7000 To0q 900c

POWER TURBINE SPEED, rpm

Fig. 10-52 Nominal Rated Performance for Continuous Duty, ISO Matched Gas Fueled, Gas Turbine. Source: Solar Turbines with combustion gas exits as a clean, dry, oxygen-rich stream at temperatures of approximating 1,000°F (490°C). Supplementary firing with duct-burners can increase heat recovery capacity and efficiency by increasing the temperature of the exhaust.

Gas Turbine Exhaust Characteristics Under Part-load Operation

Reducing fuel input to the gas turbine under part-load operation causes a reduction in exhaust gas temperature, particularly with single-shaft turbines, which maintain constant exhaust flow. Some applied turbine designs feature IGVs, which reduce mass flow under part loads, thereby maintaining relatively higher exhaust temperatures.

Figures 10-54, 10-55, and 10-56 provide representative samples of gas turbine exhaust performance characteristics as a function of percent of full-load operation for applied turbine designs featuring single-shaft, two-shaft, and singleshaft with IGV. Figure 10-54 depicts recoverable exhaust energy versus load. Figures 10-55 and 10-56 depict exhaust flow versus load and exhaust temperature versus load, respectively.

Fig. 10-54 Recoverable Gas Turbine Exhaust Energy vs. Load. Source: Cogen Designs, Inc.

Fig. 10-55 Gas Turbine Exhaust Flow vs. Load. Source: Cogen Designs, Inc.

Fig. 10-56 Gas Turbine Exhaust Temperature vs. Load. Source: Cogen Designs, Inc.

Fig. 10-54 Recoverable Gas Turbine Exhaust Energy vs. Load. Source: Cogen Designs, Inc.

Figure 10-54 indicates a fairly linear relationship for all three applied designs, with the percent of full-load recoverable exhaust energy being slightly greater than the corresponding percent of full-load. Notice in Figure 10-55 that exhaust flow remains constant with the single-shaft design. The two-shaft design shows a fairly linear relationship, though exhaust flow is disproportionately high throughout the entire range. The single-shaft design featuring IGVs shows a fairly linear relationship down to 80% of full-load operation and remains constant at lower loads. Notice the relationship between the exhaust temperature in Figure 10-55 and the exhaust flow in Figure 10-56.

Fig. 10-56 Gas Turbine Exhaust Temperature vs. Load. Source: Cogen Designs, Inc.

Renewable Energy 101

Renewable Energy 101

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.

Get My Free Ebook


Post a comment