Detonation of undecomposed liquid oxidizer inside rocket engines

Abstract

A method for initiating the start of a rocket engine configured to operate with liquid fuel and liquid hydrogen peroxide includes the steps of: initially decomposing liquid hydrogen peroxide by passing it through a catalyst bed; sending the decomposition products from the catalyst bed into the rocket engine's reaction chamber and mixing the decomposition products with the liquid fuel to initiate detonation; and, after detonation has begun, directly sending liquid H2O2 and liquid fuel into the rocket's reaction chamber without passing them through the catalyst bed. The rocket system comprises a rocket engine including an initial ignition circuit that includes a catalyst bed having a size that allows for the decomposition of liquid H2O2 for the initial reaction with the liquid fuel. The rocket engine is configured to operate with liquid fuel and liquid H2O2 during initial ignition without passing the liquid H2O2 through the catalyst bed first.

Description

Technical Field

[0001] The present disclosure relates to rocket engines, and in particular to ignition and operation of rocket engines operating with liquid fuel and liquid oxidizer. The present disclosure is particularly applicable in connection with ignition and operation of rotating detonation rocket engines (RDRE) operating with liquid fuel and liquid oxidizer, and is described in connection with such applicability, but other applications are also contemplated. Background Art

[0002] A rotating detonation rocket engine (RDRE) is an engine that uses a form of pressure-gain combustion based on detonation waves traveling around an annular reaction chamber or reaction channel or annular space. In detonation combustion, this process achieves supersonic flow, and thrust is generated. RDREs are more efficient than traditional deflagration rocket engines and achieve higher specific impulse.

[0003] During operation, fuel and heated oxidizer are injected into the reaction channel, usually through small holes or slits, and detonation is initiated in the fuel / oxidizer mixture by an igniter. After the engine is started, detonation of the fuel and oxidizer mixture is sustained. That is, after the fuel / oxidizer mixture is ignited by deflagration, the released energy sequentially maintains the detonation or detonation wave front. Products of detonation combustion spread out of the reaction channel and are further pushed out of the reaction channel by incoming fuel and oxidizer, generating thrust that can move aircraft and rockets at supersonic or hypersonic speeds.

[0004] Fuels and oxidizers currently used in rocket engines need to be stored separately, and their storage life is also limited.

[0005] Furthermore, many liquid rocket fuels, such as liquid hydrogen and liquid methane, need to be stored at low temperatures. Similarly, liquid oxygen also requires continuous cooling. Solid oxidizers and fuels such as ammonium perchlorate (AP), ammonium dinitrate (AND), ammonium nitrate (AN), ammonia borane, and hydrazinium nitroformate (HNF) cannot be used in rocket engines that need to be stopped and restarted. Liquid oxygen is practically unusable with wooden rounds and cannot be stored or used without additional refueling or continuous maintenance. The commonly used oxidizers mentioned above are also contaminants. Hydrogen peroxide has the advantage of being an inherently "environmentally friendly" chemical. In the catalytic decomposition of hydrogen peroxide, 2.877 MJ of energy is released per kg of hydrogen peroxide, and environmentally friendly products are produced according to the following reactions. H2O2 → H2O + 1 / 2·O2

[0006] This reaction produces superheated steam and oxygen. 47% by weight of the products of the hydrogen peroxide decomposition reaction is molecular oxygen, and this high oxygen concentration makes it efficient for use as an oxidizer in various rocket fuels.

[0007] However, H2O2 needs to be decomposed before it can be used as an oxidizer. Previously, H2O2 was decomposed in large catalyst beds that allowed for the complete decomposition of the H2O2 flow during flight. However, such large catalyst beds significantly increase the rocket's mass and volume. [Overview of the Initiative] [Means for solving the problem]

[0008] This disclosure provides a rocket configured to operate with a fuel that is liquid at room temperature and an oxidizer that is liquid hydrogen peroxide, thereby overcoming the aforementioned problems of the prior art. This disclosure also provides a rocket engine configured to operate with liquid fuel and liquid H2O2 without requiring a catalyst bed to enable the decomposition of H2O2 during continuous operation of the rocket engine after initial ignition. In one embodiment of this disclosure, a small catalyst bed is provided to supply the decomposition products of high-temperature H2O2 in order to achieve initial ignition. After ignition is achieved, the liquid H2O2 and liquid fuel are delivered directly to the rocket's reaction chamber without passing through the catalyst bed. Typically, commercially available hydrogen peroxide contains a certain proportion of water along with the hydrogen peroxide. Such a solution of hydrogen peroxide and water is also commonly referred to as "hydrogen peroxide."

[0009] In another embodiment of the present disclosure, an RDRE is provided that is configured to operate with a liquid fuel and liquid H2O2, the RDRE including a small H2O2 starting catalyst bed, which is configured to deliver the high-temperature decomposition products of H2O2, namely oxygen, superheated steam, and hydroxyl radicals, as initiators into the combustion channel to ignite the liquid fuel, which is separately delivered to the reaction chamber. After combustion has started, the starting catalyst bed is taken offline, and the liquid H2O2 and liquid fuel are delivered directly to the reaction chamber, where the liquid H2O2 decomposes under high temperature and pressure conditions and reacts with the fuel.

[0010] In another embodiment of the present disclosure, initial ignition is achieved by supplying a mixture of H2O2 decomposition products from a small H2O2 starting catalyst bed, a low molecular weight fuel such as propane, or a hypergolic fuel (spontaneous fuel), and a conventional liquid rocket fuel to a predetonation tube. After ignition is achieved, the catalyst bed and predetonation tube are taken offline, and the fuel supply is switched to a conventional liquid rocket fuel supply, sending the conventional liquid rocket fuel and liquid H2O2 directly to the reaction chamber.

[0011] In one embodiment, the liquid fuel includes kerosene, RP-1 (Rocket Propellant 1), or a traditional liquid hydrocarbon fuel such as JP-8 (Jet Propellant 8).

[0012] In another embodiment, the initiator comprises a hypergolic igniter such as a borane-based fuel (e.g., ammonium borane, diborane, pentaborane, triethylborane), or an ether such as diethyl ether, or tetrahydrofuran (THF).

[0013] In another embodiment, the rocket engine is an RDRE.

[0014] Specifically, in another embodiment, a method is provided for initiating the start of a rocket engine configured to operate with liquid fuel and liquid hydrogen peroxide, the method being: (a) A step of initially decomposing liquid hydrogen peroxide by passing it through a catalyst bed, (b) Sending the decomposition products from the catalyst bed to the reaction chamber of the rocket engine, mixing the decomposition products with the liquid fuel to initiate detonation, (c) After detonation has started, the liquid hydrogen peroxide and the liquid fuel are sent directly to the rocket's reaction chamber without passing through the catalyst bed, Includes.

[0015] In one embodiment, the catalyst bed is configured to be smaller than the size of the catalyst bed required for the continuous operation of the rocket.

[0016] In another embodiment, the decomposition products and the liquid fuel are initially sent to a predetonation tube where the reaction is initiated, and the reaction products from the predetonation tube are sent to the rocket's reaction chamber.

[0017] In another embodiment, a low molecular weight fuel such as propane is also introduced into the predetonation tube.

[0018] In another aspect, propane is introduced into said predetonation tube as a propane slug.

[0019] In another aspect, the liquid fuel comprises JP-8 or RP-1.

[0020] In another aspect, at least a portion of said fuel comprises a hypergolic fuel.

[0021] In another aspect, the rocket engine comprises a rotating detonation rocket engine (RDRE).

[0022] The present disclosure further provides a rocket system comprising a rocket engine configured to operate with liquid fuel and liquid hydrogen peroxide, said rocket system comprising an initial ignition circuit including a sized catalyst bed configured to enable decomposition of liquid H₂O₂ for initial reaction with the liquid fuel, said rocket engine being configured to operate directly with liquid fuel and liquid H₂O₂ without first passing liquid H₂O₂ through said catalyst bed during initial ignition.

[0023] In one aspect, the catalyst bed is configured to be smaller than a size required for use in continuous operation of the rocket engine.

[0024] In another aspect, the rocket system further comprises a predetonation chamber disposed between the catalyst bed and a main reaction chamber of the rocket engine, wherein decomposition products from the catalyst bed and the fuel are initially reacted in the predetonation tube.

[0025] In another aspect, the rocket engine comprises a rotating detonation rocket engine (RDRE).

[0026] The present disclosure further provides a method for igniting and operating a rocket engine configured to operate with liquid fuel and a liquid oxidizer, wherein the liquid oxidizer comprises liquid H2O2, the method comprising: (a) initially decomposing liquid H2O2 into oxygen and superheated steam, feeding decomposition products of oxygen and superheated steam into a reaction chamber of the rocket engine, and allowing the decomposition products to mix with rocket fuel to initiate detonation; (b) after detonation is initiated, feeding liquid H2O2 directly into the reaction chamber of the rocket engine without passing through a catalyst bed. The method comprises the above steps.

[0027] Further scope of applicability will become apparent upon reading the description provided herein. The description and specific examples in this summary of the invention are intended for illustrative purposes only and are not intended to limit the scope of the present disclosure. Other features and advantages of the present disclosure will become apparent upon reading the following description made with reference to the accompanying drawings. Brief Description of the Drawings

[0028] [Figure 1] FIG. 1 is a schematic diagram of a rocket engine according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of a rocket engine according to a second embodiment of the present disclosure. [Figure 3] FIG. 3 is a flow diagram illustrating starting and operation of a rocket engine according to the present disclosure. Mode for Carrying Out the Invention

[0029] The exemplary embodiments are described in detail below with reference to the accompanying drawings. Exemplary embodiments are provided so that the disclosure and its scope may be sufficient for those skilled in the art. Many specific details, such as examples of particular components, devices, and methods, are described so that the embodiments of this disclosure may be fully understood. Those skilled in the art will not need to adopt specific details, and it will be clear that the exemplary embodiments are embodied in many different forms, none of which should be construed as limiting the scope of this disclosure. Some exemplary embodiments do not describe in detail well-known processes, well-known device structures, and well-known techniques.

[0030] The terminology used herein is for illustrative purposes only, and not to limit, specific exemplary embodiments. Where a term is used in the singular form, it does not exclude the possibility of plural forms unless explicitly stated otherwise by context. The terms “contain,” “have,” and “equip” are non-exclusive and therefore describe the existence of specified features, integers, steps, actions, elements, components, and / or groups, but do not exclude the existence or addition of one or more other features, integers, steps, actions, elements, components, and / or groups. The steps, stages, and actions of the methods described herein should not be interpreted as having to be performed in a specific order described or illustrated unless specifically designated as the order of execution. It should also be understood that additional or alternative steps may be employed.

[0031] When an element or layer is referred to as "on," "engaged with," "connected to," or "joined" with respect to another element or layer, it may be directly "on," "engaged with," "connected to," or "joined" with respect to that element or layer, but there may also be an intervening element or layer. In contrast, when an element is referred to as "directly on," "directly engaged with," "directly connected to," or "directly joined" with respect to another element or layer, it may indicate that there is no intervening element or layer. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between," "directly between," "adjacent," and "directly adjacent"). The term "and / or" used here means that any combination of one or more of the enumerated elements is included.

[0032] The terms "first," "second," and "third" used herein may be used to describe various elements, components, regions, layers, and / or parts, but these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms may be used solely to distinguish one element, component, region, layer, or part from another. The terms "first," "second," and other numerical terms used herein do not imply order or sequence unless explicitly indicated by the context. Thus, the first element, first component, first region, first layer, or first part discussed below may also be called the second element, second component, second region, second layer, or second part without departing from the teaching of the exemplary embodiments.

[0033] To explain the relationship between one element or feature shown in the diagram and another, terms describing relative spatial relationships, such as “inside,” “outside,” “below,” “down,” “up,” and “top,” may be used here for ease of explanation. These terms describing relative spatial relationships may be intended to encompass various orientations, in addition to the orientation depicted in the diagram for a device in use or operation. For example, if the device in the diagram is reversed, the element described as “below” another element or feature would be facing “above” that other element or feature. Therefore, the illustrative term “below” may encompass both up and down orientations. The device may also be oriented in other orientations (90-degree rotation or other orientations), and the terms describing relative spatial relationships used here should be interpreted accordingly.

[0034] "Traditional liquid rocket fuel" refers to fuels that are liquid at room temperature and pressure, such as JP-8 (jet propellant 8) or RP-1 (rocket propellant 1) grade kerosene, as exemplified. Other useful liquid rocket fuels that are easily ignited include pentaborane, cyclopentane, cyclobutane, tetrahydrofuran, and diethyl ether. Low molecular weight fuel refers to C2-C6 hydrocarbons or low molecular weight alcohols, ethers, and esters. Liquid fuel refers to rocket propellants that are liquid at room temperature and pressure, such as kerosene, methanol, and gasoline.

[0035] Referring to Figure 1, a rocket system 10 according to one embodiment of the present invention is shown. The rocket system 10 includes a liquid fuel storage tank 12 configured to store liquid fuel such as a high molecular weight hydrocarbon such as JP-8, and an oxidizer storage tank 14 configured to store liquid H2O2. The rocket system 10 includes a rocket engine 16 having a reaction chamber or combustion chamber 18. In this reaction chamber 18, the fuel and oxidizer are ignited and diffuse from this reaction chamber 18 through a nozzle section 19 to propel the rocket forward. A small pre-ignition catalyst bed 20 is provided between the liquid H2O2 oxidizer storage tank 14 and the rocket's reaction chamber 18. The flow of liquid H2O2 through the catalyst bed 20 is controlled by a valve 22 under the control of a controller 24.

[0036] During startup, liquid H2O2 is sent from the oxidizer storage tank 14 to the catalyst bed 20. In the catalyst bed 20, the H2O2 is decomposed into oxygen and superheated steam. The decomposed oxygen and superheated steam are sent to the rocket's reaction chamber 18, where they are mixed with fuel supplied from tank 12 to achieve initial combustion. After initial combustion is achieved, valve 22 is closed, and liquid H2O2 is directly supplied to the reaction chamber 18 via valve 25 and line 26. Here, the H2O2 decomposes under high temperature and high pressure conditions in the reaction chamber 18 and reacts with the liquid fuel from tank 12 supplied via valve 27 and line 28. The reaction continues as long as fuel and liquid H2O2 are supplied to the reaction chamber 18. The rocket system 10 includes pumps, conduits, valves, control devices, etc. (not shown), which are conventional and well known to engineers in the field of rocket engines.

[0037] Referring to Figure 2, an alternative embodiment of the rocket system 50 includes a storage tank 52 for liquid H2O2 and a storage tank 54 for liquid hydrocarbon fuel. However, in this embodiment, the liquid H2O2 initially passes through a small catalyst bed 56, where it is decomposed into oxygen and superheated steam, and these decomposition products are then sent through a conduit 68 to a predetonation tube 60. In this predetonation tube 60, the decomposition products of the decomposed H2O2 are mixed with hydrocarbon fuel sent through a conduit 64. After ignition is achieved in the predetonation tube 60 and the high-temperature gaseous product is sent to the reaction chamber 66, the flow of liquid H2O2 through the catalyst bed 56 is stopped by closing valve 70, and the flow of hydrocarbon fuel to the predetonation tube 60 is stopped by closing valve 72, and the flow of liquid H2O2 and fuel is sent to the reaction chamber 66 via valve 67, conduit 69, valve 71 and conduit 73. Here, the liquid H2O2 is decomposed under high temperature and high pressure conditions in the reaction chamber 66, and the reaction continues as long as H2O2 and fuel are supplied to the reaction chamber 66. Valves 67, 70, 71 and 72 are controlled by controller 76. Similar to the embodiment in Figure 1, the rocket system 50 in Figure 2 further includes pumps, conduits, valves, control devices, etc. (not shown), which are conventional and well known to engineers in the field of rocket engines.

[0038] A key feature and advantage of this disclosure is the ability to make the catalyst bed extremely small, because this catalyst bed is used only to achieve the initial reaction. After the reaction has started, liquid H2O2 and liquid fuel are directly delivered to the rocket's reaction chamber, where the high temperature and pressure conditions decompose the H2O2. As a result, there is no need to decompose the H2O2 before introducing it into the rocket's reaction chamber, enabling continuous operation of the rocket engine. Consequently, the packaging efficiency of the oxidizer catalyst bed is greatly improved.

[0039] Various modifications are possible to the above disclosure without departing from its spirit and scope. For example, referring again to Figure 2, initial ignition can be achieved by introducing low molecular weight hydrocarbons such as propane, or other fuels that are more volatile or easier to ignite (compared to the main rocket fuel), such as MAPP® gas (a mixture of methylacetylenepropadiene and propane), or other unsaturated volatile fuels, together with the conventional rocket fuel from the supply tank 80 into the predetonation tube 60. After achieving initial ignition, the flow of low molecular weight hydrocarbons into the predetonation tube 60 is stopped by closing the valve 82 and ceasing the supply of H2O2 and the conventional rocket fuel to the predetonation tube 60. It is also possible to initiate combustion using only low molecular weight hydrocarbon fuel and the decomposition products of H2O2.

[0040] Figure 3 illustrates the startup and operation of a liquid-fueled rocket according to this disclosure. The overall process 100 is as follows: In startup step 120, liquid hydrogen peroxide from the liquid hydrogen peroxide storage 102 passes through the catalyst bed 104, where it is decomposed into oxygen and superheated steam. In the decomposition step, some partially reacted hydroxyl radicals may also be formed. The decomposition products from the catalyst bed 104 are sent to the rocket engine reaction chamber 108, where they are mixed with liquid rocket fuel sent from the rocket fuel storage 106 to achieve initial detonation. After achieving initial detonation, in step 130, liquid hydrogen peroxide is sent directly to the rocket engine reaction chamber without passing through the catalyst bed, and the rocket engine operates continuously.

[0041] The above descriptions of embodiments are provided for illustrative and explanatory purposes only. They are not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment and, where applicable, are interchangeable and can be used in selected embodiments, even if not specifically shown or described. This allows for various forms of modification. Such modifications do not constitute a departure from the disclosure, and all such modifications fall within the scope of the disclosure. Various modifications and advantages can be made to the disclosure without departing from the spirit and scope of the disclosure.

Claims

1. A method for initiating the start of a rocket engine configured to operate on liquid fuel and liquid hydrogen peroxide, (a) A step of initially decomposing liquid hydrogen peroxide by passing it through a catalyst bed, (b) A step of sending the decomposition products from the catalyst bed to the reaction chamber of the rocket engine, mixing the decomposition products with the liquid fuel to start detonation, (c) After detonation has started, the step of directly sending the liquid hydrogen peroxide and the liquid fuel to the reaction chamber of the rocket without passing through the catalyst bed, A method that includes this.

2. The catalyst bed is configured to be smaller than the size of the catalyst bed required for continuous operation of the rocket. The method according to claim 1.

3. The aforementioned liquid fuel includes a low molecular weight fuel and is used for initial starting. The aforementioned liquid fuel includes hypergolic fuel and is used for initial starting. Low molecular weight fuel is also introduced into the predetonation tube. The low molecular weight fuel includes propane, The aforementioned propane is introduced into the predetonation tube as propane slag. The aforementioned liquid fuel includes JP-8 or RP-1. At least a portion of the aforementioned liquid fuel is a hypergolic fuel. The method according to claim 1 or 2.

4. The decomposition products and the liquid fuel are initially sent to a predetonation tube, where the reaction is initiated. The reaction products from the predetonation tube are sent to the reaction chamber of the rocket. The method according to claim 1 or 2.

5. The aforementioned rocket engine is composed of a rotary detonation rocket engine (RDRE). The method according to claim 1.

6. A rocket system comprising a rocket engine configured to operate on liquid fuel and liquid hydrogen peroxide, The rocket system uses liquid H for the initial reaction with the liquid fuel. 2 O 2 It includes an initial ignition circuit that includes a catalyst bed having a size and is configured to allow disassembly of The aforementioned rocket engine, when initial ignition occurs, uses liquid H 2 O 2 Without passing it through the catalyst bed, the liquid fuel and liquid H 2 O 2 It is configured to operate directly by Rocket system.

7. The catalyst bed is configured to be smaller than the size required for continuous operation of the rocket engine. The rocket system according to claim 6.

8. Furthermore, it includes a predetonation chamber located between the catalyst bed and the main reaction chamber of the rocket engine, The decomposition products from the catalyst bed and the fuel are configured to react in the predetonation tube in the initial stages. The rocket system according to claim 6 or 7.

9. The aforementioned rocket engine is composed of a rotary detonation rocket engine (RDRE). The rocket system according to claim 6 or 7.

10. A method for igniting and operating a rocket engine configured to operate with liquid fuel and liquid oxidizer, The aforementioned liquid oxidizing agent is liquid H 2 O 2 Includes, The aforementioned method, (a) initially liquid H 2 O 2 decomposing into oxygen and superheated steam, feeding the decomposed products of oxygen and superheated steam to a reaction chamber of a rocket engine, and mixing the decomposed products with rocket fuel to initiate detonation; (b) After detonation has started, liquid H without passing through the catalyst bed 2 O 2 The steps include sending the rocket engine directly to the reaction chamber, A method that includes this.

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