GB685943A - Improvements in power plants including at least one free piston auto-gas generator - Google Patents

Abstract

685,943. Gas turbine plant. SOC. D'ETUDES ET DE PARTICIPATIONS; EAU, GAZ, ELECTRICITE, ENERGIE SOC. ANON. June 23, 1950 [July 16, 1949], No. 15785/50. Class 110(iii) [Also in Group XXVII] A gas turbine plant comprising a free piston gas generator feeding a gas turbine which is controlled, when the turbine power drops below a certain level, by means which allow some of the power gases before the turbine to be led to a second turbine which is coupled to the first turbine in such a manner that when both turbines are supplied with power gases they act with opposing torques on a power shaft. The gas turbine shown comprises a free-piston gas generator feeding a gas turbine 23 through a conduit 21 and a reservoir 20. The gas generator comprises a power cylinder 1 having a piston 2 connected to a compressor, piston 5. The air compressed on the upper side of the piston 5 is used to supercharge the power cylinder 1 and that on the lower side is used to return the piston to the upper position. The output of a fuel pump 11, driven from the piston 5 by a rod 12, is controlled by a rack 15 operated by a hand-wheel 35. A contact member 17, connected to the rack 15 and a piston 18 movable in a cylinder 19 in response to changes in the charging pressure which is related to the pressure of the power gasses leaving the ports 4, co-operates with abutment surfaces 16 of a stop. A resilient device 37 allows the surfaces 16 to operate. A conduit 30 leads from the conduit 21 to a second reverse drive turbine 25 mounted on the shaft of the turbine 23. The arrangement is such that the power output of the turbine 23 is reduced by reducing the output of the gas generator. Since there is a limit below which the output of the gas generator cannot be reduced due to the necessity of clearing the inlet and exhaust ports 3, 4, on the outward movement of the piston 1, further reduction of the power output is obtained by opening the valve 31 and bypassing some of the gases into the turbine 25. The valve 31 may be operated until the conduit 29 is shut off and all of the gases flow to the turbine 25 when the direction of rotation of the propeller 27 will be reversed. In a mid-position of the valve 31 the torques of the turbines 23, 25 will be equal and the propeller 27 will then be stationary. In a modification, the valve 31 and the fuel control 15 are operated from a common handwheel through cams.