Steam turbines usage

By common usage, the terms turboexpanders and expansion turbines specifically exclude steam turbines and combustion gas turbines, which are covered elsewhere in Sec. 29. 

The average steam requirements for the absorption chillers and the ancillary hospital usage were virtually satisfied by the turbine exhaust as the duct burner used only 5% of the total gas usage for the system (turbine plus duct burner). Moreover, 2001 was the year in which gas costs caused a curtailment in the turbine usage nonetheless, the turbine generator accounted for more than 60% of the required electricity. 

FIGURE 18.6 Block diagram for water usage in a steam turbine. 

Rust problems during usage of certain refined products, such as steam turbine oils, are controlled by addition of corrosion inhibitors. Evaluation of the performance of these inhibitors is done using ASTM D 665 or ASTM D 3603, Test Method for Rust-Preventing Characteristics of Steam Turbine Oil in the Presence of Water (Horizontal Disk Method). 

Consider an example involving a site where there are four steam mains with their steam usage and generation detailed in Table 23.3. The utility system can use a gas turbine with a power output of 25 MW, if appropriate. The gas turbine is integrated with a HRSG17. 

If the plant uses a steam-powered turbine or if the plant uses steam generators to make its own electricity, then the apparent steam usage is... 

While the above options consider use of large amount of North Slope gas there are other options which use small amounts of North Slope gas and should also be considered. One such option Is utilizing natural gas in the form of utilities for local usage. Gas turbine and steam boiler co-generator technolgies to convert natural gas into electricity are conventional and well proven commercially. The size of power plant facilities will be dictated by the local Alaskan market and economics. For large metropolitan areas like Fairbanks and Anchorage, utilization of North Slope gas by utilities does not look economical especially due to the fact that much closer Cook Inlet gas and Kenai gas fields can serve the same purpose for next 20-25 years. Other option that does not look economically attractive at the present Is the use of natural gas In the form of fuel cells. 

Most air coolers are horizontal. But some are vertical or A-irarae to save space, see Figure 9, Vertical air cooler is ideal for offihore platfomi usage, but crosswind may hamper Its performance. A-ftame air cooler is used exclusively in power plants to condensed turbine exhaust steam. 

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