CAT Titan 250 Manual De Usuario

Turbomachinery Package Specification 

250 Generator Set 

The exhaust system (Figure 25) typically consists of all components installed 
downstream of the engine exhaust bellows expansion joint, including silencers and 
ducting, that are necessary to ensure a smooth flow of exhaust gas from the engine. The 
exhaust duct system must be terminated in a manner that precludes recirculation of 
exhaust products through the engine air inlet or oil cooler. Exhaust considerations include 
the relative height of the exhaust duct above the air inlet, building roof design, direction of 
prevailing winds, and the proximity of adjacent structures. The importance of having an 
exhaust system properly designed cannot be overemphasized. A poorly designed 
exhaust system can cause loss of power capability and impose severe mechanical 
strains on the gas turbine. Exhaust systems should be designed to meet the following 
requirements: 

•  Where two or more units exhaust into a common header, such as used for heat 

recovery equipment, provisions must be made to prevent hot gas from flowing 
into the non-operating unit (common exhaust ducting is not recommended). 

•  Final termination of ducting must not allow exhaust gas to be drawn into the gas 

turbine inlet. 

•  Capability to purge the complete exhaust system prior to gas turbine lightoff. For 

short simple exhaust systems, purging should be designed to accomplish three 
air volume changes. For large complex exhaust systems, purging should be 
designed to accomplish five air volume changes either through gas turbine 
cranking or supplementary exhaust blowers. 

When exhaust silencing is required, provisions must be made to adequately mount and 
support the equipment and limit the exhaust silencer pressure loss.  

Solar can provide a silencer with support structure and ducting suitable for connection to 
the radial exhaust of the Titan 250 generator set. Brackets are available for mounting the 
silencer in a vertical or horizontal position. 

High thermal efficiencies can be obtained by using the gas turbine exhaust heat energy. 
There are several methods for using the exhaust heat and attaining greater than 80% fuel 
utilization. The methods used and the efficiencies achieved are primarily dependent on 
the type of application. The most common uses are: 

1.  Producing steam with a heat recovery steam generator (HRSG) or heating a 

process fluid with a heat recovery fluid heater. 

2.  Using the gas turbine exhaust as a source of preheated combustion air in a 

boiler or furnace (the gas turbine exhaust contains 15-18% oxygen). 

3.  Using the gas turbine exhaust directly for a drying or heating process in which 

high temperature air is necessary. A mixture of gas turbine exhaust and fresh air 
can be used in a reduced air temperature process. An air-to-air heat exchanger 
is required when the process involves any products in the human food chain. 

Solar can design and provide a complete exhaust heat recovery system to meet specific 
application requirements. The system must be designed to minimize the backpressure 
imposed on the gas turbine exhaust and provide a smooth flow transition into the exhaust 
heat recovery device. 
 

© 2008 Solar Turbines Incorporated. All rights reserved. 

TPS250GS/908 - Preliminary 

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