Patent GB-985207-A (GB)
Title: Improvements in installations including at least one gas-generator and a machine driven by gases therefrom
IPC: F02B75/02
Filed: 1961-12-14
Abstract: 985,207. Gas turbine plant; combustionproduct power plant. SOC. D'ETUDES ET DE PARTICIPATIONS EAU, GAZ, ELECTRI CITE, ENERGIE, S.A. Dec. 14, 1961 [Jan. 11, 1961], No. 44893/61. Headings F1G and F1Q. A plant comprises at least one internalcombustion, free-piston gas generator supplying power gas to a driven machine, each gasgenerator comprising connected combustion and compressor pistons operating in respective cylinders, a portion of the air compressed in the compressor cylinder being fed to a scavenge air reservoir and thence through the combustion cylinder into a delivery pipe connected to the driven machine and a portion of the compressed air being fed through a duct which bypasses the scavenge air reservoir and combustion cylinder, wherein two valves or groups of valves open automatically under the influence of their upstream and downstream pressures, one of these valves or groups of valves controlling the delivery of compressed air from the compressor cylinder to the reservoir and the other controlling the flow of compressed air to the duct. The gas generator combustion pistons 2 operate on the two-stroke Diesel cycle in a cylinder 1 provided with fuel injectors and comprising inlet ports 5 for feeding and scavenging air which is stored in the interior of the enginecase 6. The cylinder 1 also comprises exhaust ports 7 which are connected to an exhaust gas collector II, feeding a turbine III by a casing 8 which surrounds the ports 7. The compressor pistons 3 operate in cylinders 4 each divided into two compartments 4a, 4b. The inner compartment 4a forms the actual compressor cylinder, while the outer compartment 4b forms a return energy cushion for the free pistons 2, 3. Each compartment 4a is provided with one or more suction valves 9 and groups of delivery valves 10a, 1Ob The valves 10a communicate with the interior of the engine-case 6 and the valves 10A communicate with the gas-collector II through the by-pass pipe formed by ducts 11a, llb which are connected to the casing 8. In a modification the by-pass pipe or pipes extend outside the engine-case 6. In a further modification a direct connection is made between the feeding and scavenging air reservoir 6 and the exhaust collector II under the control of a valve. A number of gas generators may be combined, Fig. 3, so that the by-pass pipes form a compressed air system in parallel with the power gas system. In this case the by-pass air is fed to a combustion chamber 15 through a pipeline 12 after passing through a heating device 17, where the by-pass air is heated by the exhaust gases from the turbine 14. Alternatively, the by-pass air may be utilised in any plant where there is need of air under pressure. In a plant having two gas generators in which the engine cases 6 are in communication with each other, the bypass air from the compressor part of one gasgenerator may be directed to the exhaust collector II of the other gas-generator. Where there is an excess of scavenging air over a range of lower loads, means may be provided for automatically closing the valves 10b when the load exceeds a predetermined value. In a further modification one of the compressor cylinders 4 delivers the feeding and scavenging air, while the other compressor cylinder 4 delivers the bypass air. Alternatively a stepped compressor piston may be used.