Reverse-flow type pulse detonation combustor

[0024] Embodiment 1:

[0025] The diffuser structure 1 of the recirculation pulse detonation combustion chamber in this example can be changed according to the form of the compressor. In this embodiment, 15 radial triangular diffuser vanes are evenly distributed on the diffuser disc. Adjacent triangular diffuser vanes are spaced 24° apart. There are 40 rectifying vanes evenly distributed in the circumferential direction of the diffuser disc, the vane inlet is 45° to the axial direction, and the outlet is parallel to the axial direction. The diffuser is connected to the casing through the rectifying vanes, and there are 4 bolt holes on the diffuser disc for fixing the bearings.

[0026] The recirculation pulse detonation combustion chamber in this example contains 6 J-type recirculation detonation tubes A type 9, see figure 2 , each detonation tube is composed of a mixing section 10, a detonating straight section 11, and an exhaust bend section 12. The central axis of the detonation tube is evenly distributed along the circumferential direction, and the central angles of the central axes of the two adjacent detonation tubes are the same. is 60°, its distribution see figure 2. Outside the mixing section 10 of each detonation tube, there is an axially mounted fuel nozzle 8, and the fuel nozzle 8 extends from the outer casing of the combustion chamber into the main air intake hole 13 of the mixing section.

[0027]When the recirculation pulse detonation combustion chamber in this example works, the high-pressure air from the compressor first enters the combustion chamber after being diffused and decelerated by the diffuser. The air intake hole 13 and the auxiliary air intake hole 14 enter the detonation pipe, and at the same time, the fuel nozzle 8 injects fuel into the main air intake hole 13, and mixes with the air to form a uniform explosive mixture, and then the fully mixed explosive mixture is filled with J Type recirculation detonation tube 9 is then ignited by spark plug 7 to form detonation, and the detonation wave gradually increases in intensity after passing through the detonation enhancement device in the detonation straight section, forming many high temperature and high pressure points locally. These high temperature and high pressure points develop backward into a stable detonation wave, and the detonation wave turns 180° along the exhaust elbow and then spreads out of the detonation pipe. Due to the effect of detonation and supercharging, part of the gas in the J-type return detonation tube 9 will flow out from the main and auxiliary air intake holes in the reverse direction, and the reversed air flow will gradually weaken in the volume space between the detonation tube and the outer casing of the combustion chamber, making the The influence of backpropagation on the compressor is weakened. When the pressure in the J-type return detonation tube 9 is reduced to the incoming pressure, the detonation tube begins to refill the detonable mixture, and the above process is repeated. The six J-type return detonation tubes 9 can perform the above process at the same time, or they can perform the above process in time-sharing. During the time-sharing operation, the six J-type return detonation tubes are sequentially fueled and ignited.

[0028] Embodiment 2:

[0029] The recirculation pulse detonation combustion chamber in this example contains 6 J-type recirculation detonation tubes B type 17 See image 3 , Compared with the A-type, the B-type has no angle between the intake mixing section 18 and the detonating straight section 19, and its exhaust curved section 20 is 42.9% longer than the A-type, which is more conducive to the formation of the knock wave. Different from the A-type detonation pipe, the outlet of the exhaust bend 20 of the B-type detonation pipe is installed on the outlet of the adjacent turbine guide 6, and the 6 pipes are generally staggered. The central axis of the same B-type detonation pipe is along the It is evenly distributed in the circumferential direction, and the central angles of the central axes of the two adjacent detonation tubes are the same as 60°. Image 6.

[0030] In this example, the detonation tubes are distributed in a staggered manner. Under the same axial distance, the overall length of the detonation tubes increases, which can make the detonation wave more fully formed and generate greater thermal power.