A high-energy, wide-operating-range gaseous oxygen-methane torch igniter

Abstract

This invention relates to a high-energy, wide-operating-range gas-oxygen-methane torch igniter, comprising a housing, a methane inlet, an oxygen inlet, a conduit, and an electric spark plug interface; the housing contains a combustion chamber and a gas collecting chamber, the gas collecting chamber being an annular cavity, with two types of gas holes between the combustion chamber and the gas collecting chamber, one being a straight hole and the other an oblique hole; the oxygen inlet is connected to the combustion chamber via an oxygen channel, and the combustion chamber is connected to the conduit via an outlet; the methane inlet is connected to the gas collecting chamber; a chamber pressure inlet nozzle and an electric spark plug are also included. The spark plug interface is connected to the combustion chamber; methane enters the gas collecting chamber through the methane inlet, and is divided into two parts in the gas collecting chamber. One part of the methane is ejected through the straight hole, which impacts the oxygen flow entering the combustion chamber through the oxygen inlet to form a combustible mixture; the other part is ejected through the angled hole and flows out along the combustion chamber wall to form a cooling gas film to protect the combustion chamber wall. The spark plug interface is aligned with the position where the mixture is formed. After being energized, the spark plug ignites the combustible mixture and forms a stable flame. The flame is accelerated by the duct to form a supersonic airflow.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine technology and relates to a high-energy, wide-range gaseous oxygen-methane torch igniter. Background Technology

[0002] The reusable full-flow staged combustion cycle liquid oxygen-methane engine consists of multiple combustion components, including a thrust chamber, a fuel-rich gas generator, and an oxygen-rich gas generator. Each combustion component uses non-self-igniting propellants such as liquid oxygen (or oxygen-rich gas) and methane (or fuel-rich gas) for combustion, requiring an additional igniter. Because the engine requires multiple ignitions and repeated operation, and because the ignition environment and propellant used for each combustion component differ, the requirements for the ignition energy, flow rate, operating temperature, operating time, and reusability of the igniter also vary. To reduce the complexity of the engine system, each combustion component uses a flare igniter with the same structure for ignition. This places high demands on the igniter, requiring it to have a wide operating range and strong environmental adaptability. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a gas-oxygen-methane torch igniter with wide-range and reliable operation, which can adapt to the ignition requirements of different combustion components and solve the problem of multiple starts and repeated operation of various combustion components in liquid oxygen-methane engines.

[0004] The solution to the technical problem of the present invention is: a high-energy, wide-range gas-oxygen-methane torch igniter, which includes a housing, a methane inlet, an oxygen inlet, a conduit, and an electric spark plug interface.

[0005] The shell has a combustion chamber and an air collection chamber inside. The air collection chamber is an annular cavity. There are two types of air holes between the combustion chamber and the air collection chamber: one type is a straight hole and the other type is an oblique hole.

[0006] The oxygen inlet is connected to the combustion chamber via an oxygen passage, and the combustion chamber is connected to a duct via an outlet; the methane inlet is connected to the gas collection chamber; the chamber pressure inlet nozzle and spark plug interface are connected to the combustion chamber.

[0007] Methane enters the gas collecting chamber through the methane inlet. Inside the gas collecting chamber, it is divided into two parts. One part of the methane is ejected through the straight hole, which impacts the oxygen flow entering the combustion chamber through the oxygen inlet to form a combustible mixture. The other part is ejected through the angled hole and flows out along the combustion chamber wall to form a cooling gas film that protects the combustion chamber wall.

[0008] When the spark plug interface is aligned with the air-fuel mixture formation position, the spark plug ignites the combustible mixture after power is applied, forming a stable flame. The flame is accelerated by the conduit to form a supersonic airflow.

[0009] Preferably, the oxygen channel comprises two parts: a cylindrical cavity and an expansion channel; oxygen first enters the cylindrical cavity, and then is decelerated by the expansion channel to form a uniform low-speed oxygen flow.

[0010] Preferably, the velocity of the uniform low-speed oxygen flow generally does not exceed 50 m / s.

[0011] Preferably, the angle of the expansion channel does not exceed 40°.

[0012] Preferably, the catheter is an expandable catheter.

[0013] Preferably, there are two straight holes.

[0014] Preferably, the spark plug interface has two parts.

[0015] Preferably, the gas collection chamber is closed by an annular cover plate, and the methane inlet is installed on the cover plate and connected to the gas collection chamber.

[0016] Preferably, the above-mentioned high-energy, wide-operating-range gaseous-oxygen-methane torch igniter further includes a chamber pressure connector, which is used to connect to a pressure sensor to measure the pressure inside the combustion chamber.

[0017] Preferably, the aforementioned high-energy, wide-range gas-oxygen-methane torch igniter is applied to the thrust chamber and gas generator of a reusable liquid oxygen-methane rocket engine.

[0018] The advantages of this invention compared to the prior art are:

[0019] (1) The present invention decelerates oxygen through two steps: oxygen expansion channel and impact, which can adapt to different flow rates, different pressures and a wide range of mixing ratios.

[0020] (2) The present invention uses an electric spark plug near the impact point to ignite the high-mixing-ratio gas mixture of oxygen and methane after impact to form a high-temperature stable oxygen-rich flame.

[0021] (3) The flame of the present invention is accelerated by the expansion outlet duct to form a supersonic airflow, which increases the penetration depth of the airflow and increases the contact area between the high temperature gas and the propellant in the downstream combustion component, which is beneficial to igniting propellants in different states.

[0022] (4) The present invention can adapt to the ignition requirements of different combustion components and solves the problem of multiple starts and repeated operation of each combustion component of liquid oxygen methane engine. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to an embodiment of the present invention;

[0024] Figure 2 for Figure 1 AA cross-section view; Detailed Implementation

[0025] The present invention will be further described below with reference to the embodiments.

[0026] This invention addresses the technical problems arising from the requirements of multiple ignitions and wide-range stable operation of igniters by providing a high-energy, wide-range gaseous-oxygen-methane flare igniter. This high-energy, wide-range gaseous-oxygen-methane flare igniter does not allow large accumulation of methane to avoid explosion, and it also ensures rapid engine ignition to avoid high ignition pressure peaks. The flare igniter is required to have a wide operating range, be reusable multiple times, and have extremely high ignition reliability.

[0027] like Figure 1 , Figure 2 As shown, the gas-oxygen-methane torch igniter provided by the present invention includes a housing, a methane inlet 6, an oxygen inlet 5, a conduit 3, an electric spark plug interface 8, and a chamber pressure inlet nozzle 7.

[0028] The shell has a combustion chamber and an air collection chamber inside. The air collection chamber is an annular cavity. There are two types of air holes between the combustion chamber and the air collection chamber: one type is a straight hole and the other type is an oblique hole.

[0029] The oxygen connector is connected to the combustion chamber via an oxygen passage, and the combustion chamber is connected to a conduit via an outlet; the methane connector is connected to the gas collection chamber; the chamber pressure connector and the spark plug interface are connected to the combustion chamber.

[0030] Methane enters the gas collecting chamber through the methane inlet 6. Inside the gas collecting chamber, it is divided into two parts. One part of the methane is ejected through the straight hole, which impacts the oxygen flow entering the combustion chamber through the oxygen inlet to form a combustible mixture. The other part is ejected through the angled hole and flows out along the combustion chamber wall to form a cooling gas film that protects the combustion chamber wall.

[0031] When the spark plug interface is aligned with the air-fuel mixture formation position, the spark plug ignites the combustible mixture after power is applied, forming a stable flame. The flame is accelerated by the conduit to form a supersonic airflow.

[0032] The oxygen channel comprises two parts: a cylindrical cavity and an expansion channel. Oxygen first enters the cylindrical cavity, and then is slowed down by the expansion channel to form a uniform, low-velocity oxygen flow. The velocity of the uniform, low-velocity oxygen flow does not exceed 50 m / s.

[0033] The angle of the expansion channel does not exceed 40°.

[0034] The catheter is an expandable type.

[0035] The spark plug interface has two parts. In actual operation, the igniter can operate with a single spark plug; the two parts are provided for backup.

[0036] The gas collection chamber is closed by an annular cover plate, and the methane inlet is installed on the cover plate 4 and connected to the gas collection chamber.

[0037] The chamber pressure connector is used to connect a pressure sensor to measure the pressure inside the combustion chamber.

[0038] There are two straight holes, arranged symmetrically. There are multiple oblique holes. The central axis of the oblique holes forms a certain angle with the plane of symmetry of the igniter axis.

[0039] This invention utilizes oxygen and a small portion of gaseous methane for impact, creating a low-velocity combustible mixture near the impact point. An electric spark plug is placed near the impact point for ignition, igniting the high-mixture-ratio oxygen and methane mixture to form a high-temperature, stable, oxygen-rich flame. The impact deceleration scheme can adapt to different flow rates, pressures, and a wide range of mixing ratios. The combustible mixture is ignited by the spark plug near the impact point, forming a stable flame at the center of the combustion chamber. Most of the methane impacts the wall surface and flows downstream, forming a cooling film to cool the wall and gradually mixing with the central combustion gas. The swirling methane in the throat gradually mixes and burns with the mainstream high-temperature, oxygen-rich flame, increasing ignition energy and ultimately forming a uniform, high-temperature, high-speed gas jet for ignition of different combustion components.

[0040] Oxygen enters the cylindrical cavity through the oxygen inlet, and after being decelerated by the outlet expansion channel, forms a uniform low-speed oxygen flow. Methane enters the gas collecting chamber through the methane inlet, where it is divided into two parts. A small amount (e.g., about 6%) of methane is ejected through the two small holes shown, impacting the oxygen flow to form a combustible mixture. An electric spark plug is positioned at the front of the mixture formation location. After energization, the spark plug ignites the combustible mixture, forming a stable flame. The flame is accelerated by the expanding outlet conduit to form a supersonic airflow, increasing the airflow penetration depth and the contact area between the high-temperature gas and the propellant in the downstream combustion components, which is beneficial for igniting propellants in different states. The remaining large amount of methane is ejected through the oblique holes, impacting the wall surface to form a cooling gas, protecting the inner walls of the igniter front section 1, igniter rear section 2, and conduit 3. Because the low-speed combustible mixture formed by the impact of methane and oxygen near the spark plug is easily ignited, it can adapt to different flow rates, different pressures, and a wide range of mixing ratios.

[0041] This invention provides a wide-range reliable liquid oxygen-methane flare igniter, employing a technical solution of combustion organization through the interaction of a small amount of methane with all the oxygen, electric spark plug ignition, and large-volume methane jet cooling. This results in a wide-range reliable operating capability and strong environmental adaptability. This invention is primarily applied to the thrust chamber and gas generator of reusable liquid oxygen-methane rocket engines. Due to the combination of liquid oxygen and methane, large methane accumulation is not permitted to avoid explosion, and rapid engine ignition is required to avoid high ignition pressure peaks. Therefore, the flare igniter must possess a wide operating range, be reusable multiple times, and have extremely high ignition reliability.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A high-energy, wide-operating-range gaseous oxygen-methane torch igniter, characterized in that... Includes housing, methane connector, oxygen connector, conduit, and spark plug interface; The shell has a combustion chamber and an air collection chamber inside. The air collection chamber is an annular cavity. There are two types of air holes between the combustion chamber and the air collection chamber: one type is a straight hole and the other type is an oblique hole. The oxygen connector is connected to the combustion chamber via an oxygen passage, and the combustion chamber is connected to a conduit via an outlet; the methane connector is connected to the gas collection chamber; the chamber pressure connector and the spark plug interface are connected to the combustion chamber. Methane enters the gas collecting chamber through the methane inlet. Inside the gas collecting chamber, it is divided into two parts. One part of the methane is ejected through the straight hole, which impacts the oxygen flow entering the combustion chamber through the oxygen inlet to form a combustible mixture. The other part is ejected through the angled hole and flows out along the combustion chamber wall to form a cooling gas film that protects the combustion chamber wall. When the spark plug interface is aligned with the air-fuel mixture formation position, the spark plug ignites the combustible mixture after power is applied, forming a stable flame. The flame is accelerated by the conduit to form a supersonic airflow. The oxygen channel consists of two parts: a cylindrical cavity and an expansion channel. Oxygen first enters the cylindrical cavity, and then is slowed down by the expansion channel to form a uniform low-speed oxygen flow. The conduit is an expansion type conduit.

2. The high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, The velocity of the uniform, low-speed oxygen flow does not exceed 50 m / s.

3. The high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, The angle of the expansion channel does not exceed 40°.

4. The high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, There are two straight holes.

5. A high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, The spark plug has two interfaces.

6. A high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, The gas collection chamber is sealed by an annular cover plate, and the methane inlet is installed on the cover plate and connected to the gas collection chamber.

7. A high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, It also includes a chamber pressure connector, which is used to connect a pressure sensor to measure the pressure inside the combustion chamber.

8. A high-energy, wide-operating-range gaseous oxygen-methane torch igniter according to claim 1, characterized in that, It is used in the thrust chamber and gas generator of reusable liquid oxygen methane rocket engines.

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