JP2647507B2 - Liquid methane fuel air liquefied engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid methane fuel air liquefied engine applied to obtain a propulsion force of a rocket booster, a spacecraft and the like.

[Conventional technology]

Conventional air liquefied engines used to obtain the propulsive power of rocket boosters and space vehicles use liquid hydrogen or slush hydrogen (a mixture of liquid hydrogen and solid hydrogen) as a fuel, Alternatively, slush hydrogen is used as a cold heat source (refrigerant) to liquefy air taken in from the outside, burn liquefied air and hydrogen, and operate a rocket engine.

[Problems to be solved by the invention]

The conventional air liquefied engine has the following problems to be solved.

That is, in the conventional air liquefied engine, a rocket engine using liquid hydrogen or slush hydrogen as fuel is employed. Such liquid hydrogen and slush hydrogen as fuel for cryogenic air engine, because the density is very small (respectively 0.071gr / cm ³ and 0.081gr / cm ^3), the volume of the fuel tank becomes excessive, rocket boosters and space There is a problem that causes the weight of the roundtrip aircraft to increase.

Therefore, in order to reduce the volume of the fuel tank, the fuel was liquefied with liquid methane (density of 0.423 gr / c
m ³ ).

However, in an air liquefied engine using liquid hydrogen as fuel, the boiling point of liquid hydrogen is 20k and the liquefaction temperature of air at atmospheric pressure is 79k, so it is possible to liquefy air using liquid hydrogen as a cold heat source. In the case of an air liquefied engine using methane and fuel, the boiling point of liquid methane is
Since it is 111.5k, which is higher than the liquefaction temperature of air, there is a problem that air liquefaction using liquid methane is generally impossible.

[Means for solving the problem]

The present invention provides, as a means for solving the above problems, an air compressor for compressing an air liquefaction temperature to a temperature equal to or higher than the boiling point of liquid methane, an air liquefier for liquefying the air compressed by the compressor by the heat of vaporization of the liquid methane, A liquid methane tank that stores the liquid methane that is decompressed and supplied to the air liquefier to be subjected to air liquefaction while generating thrust by burning the air liquefied by the air liquefier as a supporting agent, and the air liquefier. Inhalation of liquid methane provided for air liquefaction at
An object of the present invention is to provide a liquid methane fuel air liquefied engine comprising an ejector for discharging to the outside.

[Action]

Since the present invention is configured as described above, it has the following operation.

(1) Decompression of liquid methane lowers the boiling point of liquid methane. For example, a boiling point of 111.5 k at atmospheric pressure is 102 k at a pressure of 0.43 kg / cm ² abs and a pressure of 0.2
At 8 kg / cm ² abs, it drops to 98 k.

(2) By increasing the pressure of the intake air, the liquefaction temperature of the air, that is, the boiling point increases. For example, the pressure rises to 106 k at a pressure of 10 kg / cm ² abs and to 110 k at a pressure of 12.8 kg / cm ² abs.

(3) As described in (1) and (2) above, since the boiling point of liquid methane is lower than the air liquefaction temperature, the latent heat of vaporization of liquid methane (126.1 kcal / kg at a pressure of 0.43 kg / cm ² abs, pressure of 0.2
Air can be liquefied using 127.5 kcal / kg at 8 kg / cm ² abs).

(4) In addition, liquid methane used for liquefaction of air in an air liquefier, in fact, liquid methane in which the latent heat of vaporization is used for liquefaction of air and a part or all of which becomes gas,
For example, the liquid methane supplied to the air liquefier is depressurized because it is sucked by the ejector driven by the exhaust energy of the rocket engine and released to the outside. The pressure at which the boiling point is lower than the temperature can be maintained.

(5) As a result, air liquefaction using liquid methane becomes possible, and liquid methane, which has a higher density and higher loading efficiency than hydrogen, can be converted into a fuel. An air liquefied engine can be achieved in which the volume of the tank is reduced and the purpose of avoiding an increase in the weight of the rocket is achieved.

〔Example〕

 A first embodiment of the present invention will be described with reference to FIG.

In FIG. 1, liquid methane is stored in a tank 1 at an atmospheric pressure (1.033 kg / cm ² abs) and a boiling point temperature (111.5 k). The liquid methane for the refrigerant passes through the throttle 2, is decompressed to 0.43 kg / cm ² abs or less at which the boiling point becomes 102 k or less, passes through the air liquefier 3, and is installed at the tip of the nozzle 12 of the rocket engine. It is sucked by the ejector 4 driven by the exhaust energy of the engine and discharged to the outside. Further, the pressure of the liquid methane for combustion is increased by the pump 5, guided to the copying machine 6 and injected into the combustion chamber 7. Air enters through an air inlet 8, enters an air compressor 10 through an air precooler 9, and is compressed by the air compressor 10 to a pressure higher than the boiling point of the depressurized liquid methane. Enter the liquefier 3.

In the air liquefier 3, the air is liquefied by the heat of evaporation of the liquid methane refrigerant. The liquefied air in which the air has been liquefied is increased in pressure by a pump 11, enters an air precooler 9, and thereafter is guided to an injector 6 and injected into a combustion chamber 7. Also,
The liquid methane that has liquefied air in the air liquefier 3 and at least partially vaporized is sucked by the ejector 4 that is driven by the combustion gas flowing through the nozzle 12 and is discharged to the rear of the nozzle 12 together with the combustion gas. .

Further, in the combustion chamber 7, the pressure is increased by the pump 5,
The injected air burns through the injected liquid methane and the air precooler 9 and becomes a combustion gas to be ejected from the nozzle 12 to generate thrust.

 Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a diagram in which a liquid oxygen system including a tank 13, a pump 14, and a spray head 15 is added to the engine of FIG. 1 to improve the thrust per unit air flow of the engine.
Explaining the operation of the added liquid oxygen system, the pressure of liquid oxygen in the tank 13 is increased to about 15 kg / cm ² abs by the pump 14 and sprayed from the spray head 15 to the air liquefier 3.
Mix in air flow. This mixing promotes the liquefaction of the air due to the addition of a cold heat source by liquid oxygen and the increase in the oxygen concentration in the air taken in from the air intake port 8 as compared with the first embodiment. The engine thrust can be increased by increasing the amount of the oxidizing agent due to the mixing of water. Other configurations and operations are the same as those of the first embodiment.

〔The invention's effect〕

The present invention has the following effects because it is configured as described above.

That is, there is an effect that it is possible to reduce an excessively large capacity of the fuel tank, which is a drawback of the conventional air liquefied engine using liquid hydrogen or slush hydrogen (a mixture of liquid hydrogen and solid hydrogen) as fuel.

As a result, the weight of the rocket booster and the spacecraft is reduced, and the performance of the rocket can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a first embodiment of the present invention, and FIG. 2 is a schematic vertical sectional view of each liquid tank fuel / air liquefied engine of the second embodiment. DESCRIPTION OF SYMBOLS 1 ... Tank (for liquid methane), 2 ... Restrictor, 3 ... Air liquefier, 4 ... Ejector, 5 ... Pump, 6 ... Injector, 7 ... Combustion chamber, 8 ... Air intake , 9 ... air precooler, 10 ... air compressor, 11 ... pump, 12 ... nozzle, 13 ... tank (for liquid oxygen), 14 ... pump, 15 ... spray head.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Miyama 2-4-1, Hamamatsucho, Minato-ku, Tokyo Within the Space Development Corporation (72) Inventor Hiroyuki Heisha 10 Oecho, Minato-ku, Nagoya-shi, Aichi Prefecture Mitsubishi Nagoya Aerospace Systems Works, Heavy Industries, Ltd. (72) Inventor Teruyuki Aoki, 10 Oecho, Minato-ku, Nagoya, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Nagoya Aerospace Systems Works, (72) Kenji Kishimoto, Oe, Minato-ku, Nagoya, Aichi Prefecture 10 Nagoya Aerospace Systems Works, Mitsubishi Heavy Industries, Ltd. (56) References JP-A-62-237068 (JP, A)

Claims (1)

(57) [Claims] 1. An air compressor for compressing an air liquefaction temperature to a temperature equal to or higher than the boiling point of liquid methane, an air liquefier for liquefying the air compressed by the air compressor by heat of vaporization of the liquid methane, and a liquefier for the air liquefier. The compressed air is burned as a fuel to generate thrust, and a liquid methane tank for storing liquid methane which is reduced in pressure and supplied to the air liquefier to be subjected to air liquefaction is provided to the air liquefier for air liquefaction. A liquid methane fuel-air liquefied engine, comprising: an ejector that sucks the liquefied methane and discharges the liquefied methane to the outside.