GB152292A - Improvements in thermal engines and more particularly in turbines actuated by combustion products - Google Patents

Abstract

152,292. Coninck, M. R. de. Oct. 9, 1919, [Convention date]. Working-fluid supply; motor power plant.- Regulating means are provided in an internalcombustion turbine working on a Carnot cycle approximately realized by carrying out the heat exchanges in several stages with the production of work between the stages. Fig. 2 shows a gas turbine on this principle. Fuel injected through the pipe i<1> raises the temperature of the gas in the combustion chamber c<1> from T1 to T2 the gas expanding through the nozzle t<1> to the temperature T1 acquires velocity which acts on the impulse wheel r<1>, after which any remaining velocity is converted into pressure by a diffuser d<1>. The gas then enters the chamber c<2> where a similar process is carried out, and similarly in the chamber q<3> where, however, the expansion is much greater, being to a temperature T0<SP>1>, the impulse wheel r<3> being provided with several rows of blading. The gas is then cooled by a refrigerator R to a temperature To and then compressed by a wheel r<1>1 and diffuser t<1>1 of a multistage compressor to the temperature, To<SP>1>, being then again cooled to the temperature T0, and so on, till the last stage is reached, where the wheel r<1>6 will have several rows of blades to compress the gas to the temperature T1, which is then transferred to the chamber c' having completed the cycle. Valves a, a, a, b, b, b allow any stage to be put at atmospheric pressure, and if the fuel supply is reduced proportionally to the reduction in pressure the same temperature and velocity conditions will hold, but the power will be reduced proportionally, since the density of the gas is reduced proportionally. This gives a means of regulating at practically constant efficiency and speed. The combustion chambers are lined with refractory material to withstand the temperature T2; the rear end of the nozzles may be made of carborundum for this purpose. The forward end of the nozzles and the blades of the wheels are at the temperature T1, which may be less than red heat without impairing the efficiency of the cycle. The section of the blading is increased with increasing specific volume of the gas; to meet this, if the expansion is high, the turbine may be divided into two parts differing in speed and diameter and being coupled by suitable gearing E as shown in Fig. 3, where the two parts M<1>, M<2> both comprise a portion of the expansion and compression stages. By suitably selecting the stages of the part M<1> the coupling need only transmit a small fraction of the power and the blades of the part M<2> will all be at low temperature.