GB656888A - Improvements in hot-gas engines and gas turbines of the closed cycle type - Google Patents

Abstract

656,888. Hot-gas engines. BIRMINGHAM SMALL ARMS CO., Ltd., DAVIES, D. J., and NEWMAN, P. C. Jan. 24 1948, No. 2205. [Class 7(i)] [Also in Group XXVI] In a hot-gas engine or gas turbine of the closed-cycle type the fuel supply to the engine or turbine is controlled by the flow of combustion air from an engine driven blower or turbine driven compressor to a combustion chamber of the engine or turbine and variations in the controlled air flow are adapted automatically to cause appropriate variations in the amount of fuel supplied to the engine or turbine. In Fig. 1 combustion air is supplied to a combustion chamber 1 of a hot-gas engine by a blower 5 and fuel is supplied to a burner 9 by a pump 13. Excess fuel from the burner passes by way of a pipe 15 controlled by a valve 19 to a fuel tank 7. Regulation of the fuel flow is effected by means of a flow meter 17 of aerofoil type which is connected to the valve 19 by any suitable mechanism 23 which may operate either mechanically, electrically or pneumatically by, for example, levers and/or gearing electromagnetic relays or servo mechanism. Fig. 2 shows a combustion air and fuel supply system and includes means for controlling the internal air pressure in the engine. In this Figure a blower 5 supplies combustion air past a valve 25 to the combustion chamber 1, and the fuel flow from the burner 9 is controlled by a valve 19 operated by a flow-meter 17 in the air supply passage 3. The valve 25 is coupled to a hand or foot actuated or automatic control 27. The control of the flow of combustion air from the blower 5 and a control of the internal air pressure govern the speed (r.p.m.) of the engine both controls being operated by the control 27 according to the load on the engine. The valve 25 constitutes a controlled air exhaust and may be in the form of an air scoop slidably mounted within a side tube or housing secured to and extending from the air passage 3. The housing containing the scoop is disposed at an acute angle to the air passage 3, the end of the scoop projecting into the air passage to a variable extent determined by the movement imparted by the control 27. A series of apertures in the scoop cooperate with a slot in the fixed housing, so that a variable opening is provided for controlling by exhaust the air pressure in the passage 3. In a modification, Fig. 3, the control 27 adjusts the internal air pressure only, the valve 25 being operated by the servo mechanism 31 controlled by a thermocouple 33 arranged in or near the cylinder head of the engine. In another modification the control 27 is arranged and adapted to operate the air valve 25 only, the internal air pressure being adjusted by a servo mechanism 31 controlled by a temperature-sensitive device. A thermocouple arranged in or near the cylinder head of the engine or at an equivalent point in a closed-cycle gas turbine is coupled to the servo mechanism.