Patent GB-761271-A (GB)
Title: Improvements in control devices for power plant comprising at least one internal-combustion-operated gas-generator and a prime mover driven by gases from the gas-generator
IPC: C10J3/72
Filed: 1954-03-31
Abstract: 761,271. Combustion product power plant. SOC. D'ETUDES ET DE PARTICIPATIONS EAU, GAZ, ELECTRICITE, ENERGIE SOC. ANON. March 31, 1954 [April 4, 1953], No. 9487/54. Class 7 (1). [Also in Group XXVI] An internal-combustion operated gas generator feeding a prime mover having at least two ranges of control of the gas generator corresponding to two different ranges of load on the prime mover and separate adjusting means for each of these ranges has means whereby when one adjusting means reaches the limit of its range of adjustment, the succeeding adjusting means is rendered operative. One or more gas generators 1 are connected to a reservoir 20 feeding a turbine 21. A combustion chamber 22 to which fuel is supplied at high loads on the turbine is arranged between the reservoir and turbine. The fuel supply to the gas generators 1 is controlled by a rod 27. A speed governor 55 driven by the turbine 1 is arranged to control the pressure in conduits 53, 54 so that the pressure rises as the speed falls, due to increase of load on the turbine. At low loads of the turbine, the pressure in the conduits 53, 54 is such that only piston 49 is operated. This piston controls a valve 43 which co-operates with ports 45, 46 leading to the reservoir 20 and to atmosphere through conduit 47. The arrangement is such that as the port 45 is opened the port 46 is closed. During this period, the abutment 33 is forced against the cam 34 by the spring 29a so that the fuel injection control rod 27 is kept at the position of minimum output corresponding to the output pressure. The adjustment of the cam 34 in accordance with the output pressure is effected by a spring loaded piston which is connected to a compressed air chamber 11. The valve 39a is also closed by the spring 42a. On increase of load on the turbine, the pressure in conduit 53 actuates piston 32 which moves abutment 33 away from the cam 34 and so increases the fuel supply to the gas generator 1. When the abutment contacts the cam 35 the maximum output of the gas generator is reached. Any further increase in the load on the turbine is met by injecting fuel into the combustion chamber 22. For this purpose, valve 39a is opened by the piston 40. During this period, the abutment 33 contacts the cam 35 so that the gas generator is working at its maximum output. To change from one form of control to another without shock, the control in one range of load is rendered operative by the control in the preceding range reaching the end of its range. In the arrangement shown, the pistons 32, 40 actuate the fuel injection control rod 27 and the fuel valve 39a through links 30, 41 respectively. These links are mounted on rods 30b, 41b which may slide in housings until they are engaged by a brake 30c or 41c. When the piston 49 reaches the limit of its travel and the port 45 is fully open and the port 46 shut, the end of the transmission lever 51 engages the spring loaded piston 55a and so allows pressure fluid to be supplied to the cylinder and cause the brake 30c to engage the rod 30b. Movements of the piston 32 which were merely transmitted to the rod 30b are now transmitted to the link 29 and control rod 27. When all the gas generators have reached their maximum output, the abutments 33 coming into contact with cams 35 complete an electric circuit 57 which controls a relay or an electronic valve 58 to operate a slide valve 59 and so cause the brake shoe 41c to engage the rod 41b. The movements of the piston 40 are then transmitted to the valve 39a. To prevent opening of the valve 45 by the piston 49 when a gas generator is being started spring loaded valve 62 actuated by the pressures in the chamber 11 and a conduit 19 is inserted in the conduit 61 leading to the cylinder 49a. A valve 67 is provided to enable the valve 62 to be operated only when the gas generator is sufficiently hot. For starting purposes, a valve may also be inserted in the conduit 53 and the piston 32 actuated by a pressure other than that of the governor 55. A valve may also be inserted in the conduit between the valve 55a and the cylinder operating the brake 30c for the same purpose. A switch 69 in the circuit 57 may be provided to enable the operator to stop the operation of the combustion chamber 22 at any time particularly during starting. Another switch 70 operated by a spring loaded piston 71 in a cylinder 72 connected to the reservoir 20 is provided to prevent the introduction of fuel into the chamber 22 should all the gas generators fail. The contact strip 35a is extended along the bottom of the space between the cams 34, 35 so that the circuit 57 is not broken when one of the generators fails which would cause the cam support 36 to rise.