GB1137317A - Improvements in or relating to gas turbine installations - Google Patents

Abstract

1,137,317. Gas turbine plant. ELIN-UNION A. G. FœR ELEKTRISCHE INDUSTRIE. May 18, 1967, No. 23079/67. Heading F1G. A gas turbine plant comprises a gas turbine using the energy contained in the outgoing gases of a chemical process and driving a compressor which delivers combustion air to the chemical process, a heat exchanger receiving exhaust gases from the turbine, and means including a flow regulating valve for by-passing, from a point upstream of the chemical process, a part of the combustion air through the heat exchanger and then admixing the by-passed combustion air with the outgoing gases of the chemical process before entering the gas turbine. Fig. 2 shows a chemical process 2, e.g. a catalytic cracking process for the production of petrol, supplied with combustion air by a compressor 1 driven by a gas turbine 3. A part of the air delivered by the compressor is diverted through a by-pass line 7 under the control of a valve 5 and, after being heated by the turbine exhaust gases in a heat exchanger 6, joins the outgoing gases of the chamical process 2 before entering the turbine 3. The air may be additionally heated in a combustion chamber 8 by external fuels or by combustible constituents of the outgoing gases. The valve 5 is controlled hydraulically or pneumatically in dependence on the air flow sensed at 9, so that a variation of the air flow to the chemical process 2 produces a variation in the same sense of the air flow through the by-pass line 7. The resultant variation of the flow through the compressor and through the turbine causes the inlet pressure of the turbine to vary in the same sense and the delivery pressure of the compressor to vary in the opposite sense. The resultant variation in the pressure differential between the inlet and outlet of the chemical process causes the air flow through it to be maintained within narrow limits, while the mean pressure remains constant.