GB1106755A - Combustion equipment - Google Patents

Abstract

1,106,755. Gas turbine plant. ROLLSROYCE Ltd. Oct. 6, 1966 [Oct. 14, 1965], No. 43676/65. Heading F1G. [Also in Division F4] Combustion equipment comprises fractionating means for fractionating a fuel into at least two fractions one of which is of lower molecular weight than the other, there being means for passing the said two fractions to two different combustion chambers, and means for obtaining useful work from the combustion gases produced in the two combustion chambers. The plant shown in Fig. 1 is a gas turbine plant which comprises an air compressor 12, an air pre-heater 13, combustion equipment 14, a first turbine 16 which is connected to drive the compressor through shaft 17, and a second, separate power turbine 22 which is connected to drive a useful load 23 through shaft 24. The exhaust gases from the turbine 22 discharge through duct 21, a portion of the gases being tapped off through duct 26 and passed to a second combustion chamber 25 the combustion gases in which are utilized to heat the air pre-heater 13, the gases being then discharged through duct 31. A fuel fractionating means 33 is provided to which a heavy or residual oil is supplied through a first pre-heater 35 disposed in the exhaust gas duct 21 and then through a second pre-heater 36 heated by means not shown, the oil being raised to a temperature of 500‹C. The lower weight fraction boiled off passes to burners 15 in the combustion equipment 14 while the higher weight fraction passes to a burner 27 of the combustion chamber 25. The combustion equipment 14 may thus be operated at a temperature of 900‹C. which would not be possible if the heavy oil were burned directly in the equipment 14. In a second embodiment, Fig. 2, the invention is applied to combustion equipment of a steam generator and which comprises a first combustion chamber 43 to which air under pressure is supplied from a compressor 46, the air being preheated. The combustion gases from the first chamber 43 pass through duct 47 to a second combustion chamber 44 from which the gases discharge to atmosphere through duct 51. A steam generating section 63 is disposed in the chamber 44 and a steam super-heating section 64, also a steam reheat section 66 are disposed in the chamber 43. A fractionating chamber 52 is provided and heavy oil is supplied thereto through a heater 54 disposed in the combustion gas duct 47, the oil being heated to about 500‹C. The lower weight fraction boiled off passes to the burner 46 in the first chamber 43, and the heavier fraction passes to the burner 50 in the second chamber 44.