Heavy industrial gas turbines are usually to be found in refineries, chemical plants and power utilities. They are chosen mainly because of their long and reliable running times between major maintenance overhauls. They are also capable of burning most types of liquid and gaseous fuel, even the heavier crude oils. They also tend to tolerate a higher level of impurities in the fuels. Heavy industrial machines are unsuitable for offshore applications because:-
• Their poor power-to-weight ratio means that the structures supporting them would need to be much larger and stronger.
• Maintenance shutdown time is usually much longer and is inconvenient because the machine must be disassembled into many separate components. A modular concept is not possible in the design of these heavy industrial machines.
• The thermodynamic performance is usually poorer than that of the light and medium machines. This is partly due to the need for low compression ratios in the compressor.
They do, however, lend themselves to various methods of heat energy recovery e.g. exhaust heat exchangers, recuperators on the inlet air.