JP2012189018A - Fuel/oxidizer supply device for gas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that in a conventional fuel/oxidizer supply device for a gas generator, it is difficult to stably sustain combustion, and a hot spot remains, or the like.SOLUTION: In a gas generator GG for mixing and combusting fuel and an oxidizer in a state where the fuel is too much, an injection element 4 for injecting fuel and an oxidizer includes: an oxidizer injection hole 7 at the center; and four fuel injection holes 8 arranged at an equal interval around the axis line of the oxidizer injection hole 7. By employing a five-point collision type injection system, in which each of the fuel injection holes 8 is directed to one point on the axis line of the oxidizer injection hole 7, combustion is stabilized and generation of a hot spot is prevented.

Description

  The present invention relates to a fuel / oxidizer supply device for a gas generator used for supplying fuel and an oxidizer in a gas generator in which a fuel and an oxidizer are mixed and burned in an excessive fuel state.

  As a fuel / oxidizer supply device for this type of gas generator, there is one used for a gas generator constituting a liquid rocket engine. That is, in a liquid rocket engine, fuel and oxidant are pressurized by respective turbo pumps and introduced into the combustion chamber. In addition to this system, a gas generator for introducing a part of the fuel and oxidant is provided. The combustion gas generated by the gas generator is used as the driving fluid for the turbo pump.

  In addition, the above gas generator uses stainless steel piping for the distribution of combustion gas, and it is generated by mixing and burning fuel and oxidant in an excessive fuel state for the purpose of thermal protection of the piping. The temperature of the combustion gas is reduced.

  The fuel / oxidant supply device in the gas generator as described above has a structure in which injection elements for injecting fuel and oxidant are arranged on the same plane. As a conventional gas generator and its fuel / oxidant supply device, for example, as described in Non-Patent Document 1, a hot core is formed in the center, and then the hot core is diluted with fuel. There was something that adopted.

`` NASA SP-8081 LIQUID PROPELLANT GAS GENERATORS '' p.8-12

  However, in the conventional fuel / oxidizer supply device for a gas generator as described above, there is a special condition that the fuel and the oxidizer are mixed and burned in an excessive fuel state in the gas generator. There is a problem that it is difficult to maintain stably and there is a problem that a hot spot remains without uniformly mixing the fuel for dilution in the hot core, and it has been a problem to solve such a problem.

  The present invention has been made by paying attention to the above-mentioned conventional problems, and in a gas generator that mixes and burns fuel and oxidant in an excessive fuel state, combustion can be stably maintained and hot spots can be obtained. It is an object of the present invention to provide a fuel / oxidizer supply device for a gas generator that can prevent the generation of gas.

  The fuel / oxidant supply device for a gas generator according to the present invention is a device in which an injection element for injecting fuel and oxidant is arranged in a gas generator that mixes and burns fuel and oxidant in an excessive fuel state. is there.

  In the fuel / oxidant supply device, the injection element includes a central oxidant injection hole and four fuel injection holes arranged at equal intervals around the axis of the oxidant injection hole. Is a five-point collision type injection system in which the point is directed to one point on the axis of the oxidant injection hole, and the above configuration is a means for solving the conventional problems.

  According to the fuel / oxidizer supply device for a gas generator of the present invention, a five-point collision type injection element is adopted in a different collision system in a gas generator that mixes and burns fuel and oxidant in an excessive fuel state. Thus, it is possible to obtain a momentum ratio suitable for the collision of the fuel and the oxidant without changing the total flow rate and the injection speed of the fuel and the oxidant, and to adjust the jet flow from the injection element. Combustion can be maintained stably and hot spots can be prevented from occurring.

It is sectional drawing (A) and front view (B) of the element for injection in one Embodiment of the fuel / oxidizer supply apparatus for gas generators of this invention. It is sectional drawing (A) explaining a gas generator and a fuel / oxidizer supply apparatus, and a front view (B) of an injection part. It is a block diagram explaining the liquid rocket engine to which the gas generator shown in FIG. 2 is applied.

  Hereinafter, an embodiment of a fuel / oxidizer supply device for a gas generator according to the present invention will be described with reference to the drawings. The fuel / oxidant supply device shown in FIGS. 1 and 2 constitutes a part of the liquid rocket engine shown in FIG.

  The illustrated liquid rocket engine includes a combustion chamber C having an injector I, a nozzle N continuous with the combustion chamber C, a turbo pump TP1 for supplying fuel to the injector I under pressure, and the injector I A turbo pump TP2 is provided for pressurizing and supplying the oxidizing agent. As the fuel, for example, liquefied natural gas (LNG: liquefied methane) can be used, and as the oxidant, for example, liquid oxygen (LOX) can be used.

  The liquid rocket engine also includes a gas generator GG that takes in part of the fuel and oxidant introduced into the injector I and mixes and burns them. The combustion gas generated by the gas generator GG is supplied to each turbo pump TP1. , TP2 is used as a driving fluid.

  At this time, in the gas generator GG, in order not only to protect the piping from heat protection but also to operate without risk from the viewpoint of strength reduction, the fuel and oxidant are mixed and burned in an excessive fuel state, and the generated combustion gas The temperature is low (about 500 ° C.). The combustion gas that has driven the turbo pumps TP1 and TP2 can be introduced into the nozzle N and used for film cooling of the nozzle N.

  As shown in part in FIG. 2, the gas generator GG includes a fuel / oxidant supply device 2 at the end of a cylindrical combustor 1. The fuel / oxidant supply device 2 includes a flat cylindrical manifold 3 and an injection element 4 for injecting fuel and oxidant. In the manifold 3, a plurality of injection elements 4 are arranged on the same surface. It has a structure.

  The manifold 3 has a fuel circulation space 3A inside and is provided with a fuel introduction part 3B on the side, and a plurality of injection elements 4 are disposed on the injection surface 3C on the combustor 1 side shown in FIG. It is arranged.

  As shown in FIG. 1, the ejection element 4 includes a hollow shaft portion 5 having a flow path 5 </ b> A on the axis, and a large diameter portion 6 integrated with an end portion of the shaft portion 5. The large-diameter portion 6 includes a central oxidant injection hole 7 that is coaxially continuous with the flow path 5A and four fuel injection holes 8 that are arranged at equal intervals around the axis of the oxidant injection hole 7. Yes.

  In the injection element 4 described above, the oxidant injection hole 7 is formed on the axis of the element. On the other hand, each fuel injection hole 8 is open to both the front and back sides of the large-diameter portion 6 and is inclined toward one point on the axis of the oxidant injection hole 7 (one point on the axis in the injection direction). It is formed. That is, the injection element 4 is a heterogeneous collision method in which the fuel and the oxidant collide, and is a five-point collision type injection method in which each fuel injection hole 8 is directed to one point on the axis of the oxidant injection hole 7. is there.

  In the injection element 4, the surface of the large diameter portion 6 (surface on the injection side) is flush with the injection surface 3 </ b> C with respect to the manifold 3, and the shaft portion 5 penetrates the manifold 3. At this time, the back surface of the large-diameter portion 6 is in a state of facing the fuel circulation space 3 </ b> A of the manifold 3. Thereafter, an oxidant supply pipe or an oxidant supply manifold (not shown) is connected to the end of the shaft portion 5.

  As a result, the injection element 4 injects the oxidant supplied to the shaft portion 5 from the oxidant injection hole 7, and injects the fuel supplied to the fuel flow space 3 </ b> A of the manifold 3 from each fuel injection hole 8. It will be.

  The fuel / oxidizer supply device 2 for a gas generator having the above-described configuration has four fuel injection holes 8 in the injection element 4, so that, for example, one oxidant injection hole and two fuel injection holes are provided. Compared to the three-point collision type, the fuel flow rate per fuel injection hole is reduced, and each fuel is supplied to the oxidant injected from the oxidant injection hole 7 onto the center line (on the axis). Since the fuel is injected from the injection holes 8, that is, from the surrounding four sides, the oxidant having a low flow rate is not repelled by the collision with the fuel having a high flow rate.

  That is, in the above three-point collision type injector, the oxidizer having a low flow rate is likely to be repelled by the collision with the fuel having a high flow rate. As a result, the high temperature gas region (hot spot) is partially generated due to interference between the jets from the nozzles, which may cause melting of the injection portion. On the other hand, in the fuel / oxidant supply device 2 for the gas generator described above, since the five-point collision type injection element 4 is employed, it is possible to prevent a situation where the oxidant is repelled. . Of course, a four-point collision type with three fuel injection holes is also conceivable, but the effect is certain if the five-point collision type is used.

  Thereby, in said fuel / oxidizer supply apparatus 2, the momentum ratio suitable for the collision of a fuel and an oxidant can be obtained, without changing the total flow volume and injection speed of a fuel and an oxidant. In addition, since the jet flow from each injection element 4 is arranged, stable combustion can be maintained, hot spots can be prevented, and the possibility of melting of the injection surface 3C of the manifold 3 is eliminated. can do.

  Here, as in the above embodiment, when liquid oxygen is used as the oxidant, liquefied natural gas is used as the fuel, and the temperature of the combustion gas generated in the gas generator GG is about 500 ° C., combustion mixing The ratio (oxidant mass / fuel mass) is preferably about 0.25. Accordingly, the diameters of the oxidant injection hole 7 and the fuel injection hole 8 may be set so that an appropriate combustion mixture ratio can be obtained.

  As another example, when liquid oxygen is used as the oxidant and kerosene (RP-1) is used as the fuel and the temperature of the combustion gas is about 500 ° C., the combustion mixture ratio is more than the above value. It is desirable to make it smaller.

  The configuration of the fuel / oxidizer supply device for a gas generator of the present invention is not limited to the above-described embodiment, and the details of the configuration can be appropriately changed without departing from the gist of the present invention. It is.

2 Fuel / Oxidant Supply Device 4 Injection Element 7 Oxidant Injection Hole 8 Fuel Injection Hole GG Gas Generator TP1 Fuel Supply Turbo Pump TP2 Oxidant Supply Turbo Pump

Claims (3)

A fuel / oxidant supply device in which an injection element for injecting fuel and oxidant is arranged in a gas generator for mixing and burning fuel and oxidant in an excessive fuel state,
The injection element includes a central oxidant injection hole and four fuel injection holes arranged at equal intervals around the axis of the oxidant injection hole, and each fuel injection hole is a point on the axis of the oxidant injection hole. A fuel / oxidizer supply device for a gas generator, characterized in that it is a five-point collision type injection system for the gas generator.   The fuel / oxidizer supply device for a gas generator according to claim 1, wherein a plurality of the injection elements are arranged on the same surface.   2. The fuel for a gas generator according to claim 1, wherein the gas generator generates combustion gas as a driving fluid of each turbo pump for supplying fuel and for supplying oxidant in a liquid rocket engine. / Oxidizer supply device.

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