JP4196477B2 - Expander cycle engine using catalytic gas generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rocket engine equipped with a catalytic gas reactor.
[0002]
[Prior art]
Rocket engines using liquid fuel and liquid oxygen can be broadly divided into gas push and turbo pump systems. The gas push system is a rocket engine that stores liquid fuel and liquid oxygen in a pressurized tank and supplies it to the combustor with gas pressure to burn it. The structure is simple, but the thickness of the pressurized tank In the case of a large rocket, there is a disadvantage that the overall weight is increased because a pressurization system requiring a large amount of push gas is required. On the other hand, the turbo pump system stores liquid fuel and liquid oxygen in a low-pressure tank, pressurizes it using a turbo pump, and supplies it to the combustor. Since a small amount of gas is required, even a large rocket can reduce the overall weight.
[0003]
Turbo pump rocket engines can be broadly classified into three types: (a) expander cycle, (b) GG cycle, and (c) two-stage combustion cycle. The expander cycle of (a) includes a combustor 3 having two turbo pumps 1 and 2 and a cooling jacket 3 a as schematically shown in FIG. The fuel is vaporized in the cooling jacket 3a of the combustor 3, the turbo pumps 1 and 2 are rotationally driven by this gas, and the gasified fuel and liquid oxygen are supplied to the combustor 3 to generate combustion gas. ing. This cycle is particularly suitable for engines with relatively low thrust (eg 10-15 tons).
[0004]
The GG cycle of (b) further includes a gas generator (GG) as schematically shown in FIG. 2 (B), and a part of the liquid fuel pressurized by the turbo pumps 1 and 2 is part of the liquid oxygen. Combustion is performed to generate a high-temperature gas (for example, about 900 ° C.), and the turbo pumps 1 and 2 are rotationally driven by this gas, and the remaining liquid fuel and liquid oxygen are supplied to the combustor 3 to generate combustion gas. It has become.
Further, the two-stage combustion cycle of (c) includes an auxiliary combustor 4 (referred to as a gas generator or a preburner) as schematically shown in FIG. 2C, and the fuel gas vaporized in the cooling jacket 3a. The gas is generated by combustion with a small amount of oxygen, and the turbo pumps 1 and 2 are rotationally driven by the gas generated by the combustion. The exhaust gas and surplus oxygen are supplied to the main combustor 3 to generate combustion gas.
[0005]
[Problems to be solved by the invention]
The GG cycle and the two-stage combustion cycle described above are suitable for high output (for example, 50 tons or more) as compared with the expander cycle, but have the following problems.
(1) In the two-stage combustion cycle, the auxiliary combustor 4 also requires an ignition system, and the system becomes complicated. At the same time, it is difficult to match the ignition timing with the main combustor 3, and a severe temperature peak occurs at the time of ignition. There was a risk of damage. In addition, it is difficult to select / sequence an appropriate valve.
(2) The GG cycle also has the possibility of a temperature peak at the time of ignition, and the pressure of the exhaust gas that drives the turbo pumps 1 and 2 is low and exhausts to the outside as it is. there were.
[0006]
(3) On the other hand, the expander cycle does not have these problems and is simple and highly reliable, but has a problem that it is difficult to increase the output. That is, as schematically shown in FIG. 3, as the thrust is increased, the outlet temperature of the combustor tends to decrease, and the gas temperature necessary for driving the turbo pumps 1 and 2 cannot be obtained. It was.
In other words, the gas temperature for driving the turbo pumps 1 and 2 in the expander cycle is usually 400 to 500 K. However, as the size increases, the amount of heat obtained by cooling the combustor becomes insufficient, and this gas temperature decreases. The turbo pumps 1 and 2 cannot be driven sufficiently.
[0007]
The present invention has been made to solve such problems. That is, an object of the present invention is to provide an expander cycle engine that can increase the gas temperature supplied to the turbo pump as required, and can easily increase the output by driving a large turbo pump. There is.
[0008]
[Means for Solving the Problems]
According to the present invention, the fuel turbo pump (12) for pressurizing the liquid fuel, the oxygen turbo pump (14) for pressurizing the liquid oxygen, and the cooling jacket (16a) for gasifying the gas pressurized by the fuel turbo pump are provided. A combustor (16), a catalytic gas generator (18) that oxidizes and heats part of the gasified fuel gas, and an oxygen supply line (20) that supplies oxygen to the catalytic gas generator And adjusting the oxygen flow rate of the oxygen supply line to control the gas temperature heated by the catalytic gas generator, and the fuel turbo pump and the oxygen turbo pump are driven to rotate by the generated gas. An expander cycle engine is provided.
[0009]
According to the configuration of the present invention, the catalytic gas generator (18) that oxidizes and heats part of the fuel gas pressurized by the fuel turbo pump (12) and gasified by the cooling jacket (16a), and the catalyst. And an oxygen supply line (20) for supplying oxygen to the gas generator, and the temperature of the gas heated by the catalytic gas generator is controlled by adjusting the oxygen flow rate of the oxygen supply line. Since the turbo pump and the oxygen turbo pump are rotationally driven, the temperature of the outlet gas can be freely increased by increasing the oxygen flow rate in the oxygen supply line to promote the oxidation of the fuel gas in the catalytic gas generator. Accordingly, it is possible to easily increase the output by driving a large turbo pump.
[0010]
According to a preferred embodiment of the present invention, the catalytic gas generator (18) includes a platinum catalyst therein. With this configuration, an ignition system is unnecessary as in the conventional auxiliary combustor 4, and the reaction amount in the catalytic gas generator can be freely adjusted by the oxygen flow rate of the oxygen supply line. Therefore, by gradually increasing the oxygen flow rate or keeping it at a necessary minimum, the temperature rise at the start of the reaction can be moderated and damage to the turbine can be prevented.
[0011]
Moreover, it is preferable to provide the said oxygen supply line (20) with the flow volume regulator (21) which adjusts an oxygen flow rate. For example, by using a flow control valve as a flow controller, the oxygen flow rate can be gradually increased or decreased to always maintain the necessary temperature. Further, by providing a fixed orifice as a flow rate regulator, the gas temperature can be maintained at a temperature higher than the temperature at which a necessary heat balance can be achieved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.
FIG. 1 is an overall system diagram of an expander cycle engine according to the present invention. As shown in this figure, the expander cycle engine 10 of the present invention includes a fuel turbo pump 12, an oxygen turbo pump 14, a combustor 16, and a catalytic gas generator 18.
[0013]
The fuel turbo pump 12 includes a pump 12a and a turbine 12b that rotationally drives the pump 12a. The pump 12a pressurizes liquid fuel (for example, liquid hydrogen and liquefied methane), and the cooling jacket of the combustor 16 is passed through the liquid fuel line 6a. 16a is supplied.
The oxygen turbo pump 14 includes a pump 14a and a turbine 14b that rotationally drives the pump 14a, pressurizes liquid oxygen with the pump 14a, and supplies the pressurized oxygen to the combustor 16 and the catalytic gas generator 18 via the liquid oxygen line 7. It is designed to be used as an oxidant. In FIG. 1, 9a, 9b, and 21 are orifices, valves, or combinations thereof.
[0014]
The combustor 16 is a main combustor of this engine, and burns gasified fuel gas with an oxidant (oxygen) to generate a high-temperature gas (for example, about 3000 ° C.) and inject this to obtain thrust. It has become. The combustor 16 has a cooling jacket 16a surrounding the combustion chamber. The combustor main body is held at an allowable temperature or lower by the liquid fuel supplied to the inside of the combustor 16, and the liquid fuel is heated and gasified by the heat. The catalytic gas generator 18 is supplied via the fuel gas line 6b.
The temperature of the fuel gas exiting the cooling jacket 16a of the combustor 16 is 400 to 500K in a conventional small thrust expander cycle engine. However, as the size increases, the amount of heat obtained by cooling the combustor becomes insufficient. For example, it is about 300-400K.
[0015]
The catalytic gas generator 18 includes a reaction catalyst such as a platinum catalyst. The catalytic gas generator 18 is provided with an oxygen supply line 20 for supplying oxygen from the liquid oxygen line 7. Further, the line 20 is provided with a flow rate regulator 21 for adjusting the oxygen flow rate. The flow controller 21 may be a fixed orifice or a flow control valve, for example.
With this configuration, the amount of catalytic reaction (oxidation reaction) in the catalytic gas generator 18 can be freely adjusted by supplying oxygen by controlling the flow rate with the flow rate regulator 21. Therefore, by gradually increasing the oxygen flow rate or keeping it at a necessary minimum, the temperature rise at the start of the reaction can be moderated and damage to the turbine can be prevented.
[0016]
In the example of FIG. 1, liquid oxygen is directly supplied to the catalytic gas generator 18, but a part of the oxygen supply line 20 is installed around the combustor 16 to supply liquid oxygen by gasification. You may do it. Thereby, the catalytic reaction in the catalytic gas generator 18 can be performed more efficiently.
[0017]
The expander cycle engine 10 of the present invention further includes a fuel gas line 8a for supplying the high-temperature fuel gas exiting the catalytic gas generator 18 to the turbines 12b and 14b of the fuel turbo pump 12 and the oxygen turbo pump 14, and the turbine. And a fuel gas line 8b for supplying the fuel gas having passed through 12b and 14b to the combustor 16. With this configuration, the turbine gas 12b, 14b is rotationally driven by the fuel gas heated by the catalytic gas generator 18, and the fuel gas whose pressure has been reduced is supplied to the combustor 16 via the fuel gas line 8b. It is possible to obtain thrust by burning with (oxygen) and generating a hot gas (for example, about 3000 ° C.).
[0018]
With the above-described configuration of the present invention, a small amount of oxygen is sent to the catalytic gas generator 18 through the oxygen supply line 20 in an operating state where the expander engine is matched, thereby driving the turbine by catalytic reaction with platinum. The gas temperature rises. This temperature rise increases the driving capability of the turbine and powers up the entire engine. Therefore, this makes it possible to increase the size of the expander engine that could not be realized by the energy balance limitation in the conventional method. In addition, the system is simpler than a two-stage combustion cycle engine. Furthermore, it can be deployed to a pulse engine for attitude control.
[0019]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0020]
【The invention's effect】
As described above, the expander cycle engine of the present invention can increase the gas temperature supplied to the turbo pump as needed, thereby easily driving the large turbo pump and increasing the output. And so on.
[Brief description of the drawings]
FIG. 1 is an overall system diagram of an expander cycle engine according to the present invention.
FIG. 2 is a system diagram of a conventional turbo pump rocket engine.
FIG. 3 is a relationship diagram between thrust and outlet temperature of a combustor.
[Explanation of symbols]
1, 2 Turbo pump 3 Combustor (Main combustor)
3a Cooling jacket 4 Auxiliary combustor (gas generator or preburner)
6a Liquid fuel line 6b Fuel gas line 7 Liquid oxygen lines 8a and 8b Fuel gas lines 9a and 9b Orifice 10 Expander cycle engine 12 Fuel turbo pump 14 Oxygen turbo pump 16 Combustor 16a Cooling jacket 18 Catalytic gas generator 20 Oxygen supply Line 21 Flow controller

Claims (3)

Combustor (16) having a fuel turbo pump (12) for pressurizing liquid fuel, an oxygen turbo pump (14) for pressurizing liquid oxygen, and a cooling jacket (16a) for gasifying fluid pressurized by the fuel turbo pump And a catalytic gas generator (18) that oxidizes and heats part of the gasified fuel gas, and an oxygen supply line (20) that supplies oxygen to the catalytic gas generator. An expander cycle engine characterized by controlling a gas temperature heated by a catalytic gas generator by adjusting an oxygen flow rate of the gas, and rotationally driving a fuel turbo pump and an oxygen turbo pump by the generated gas. The expander cycle engine according to claim 1, wherein the catalytic gas generator (18) includes a platinum catalyst therein. The expander cycle engine according to claim 1, wherein the oxygen supply line (20) includes a flow rate regulator (21) for regulating an oxygen flow rate.

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