JP4784973B2 - Liquid oxidant, propellant using the same, and high-temperature gas generation method - Google Patents

Description

  The present invention relates to a highly safe liquid oxidizer used for liquid propellants and hybrid propellants, a propellant using the same, and a method for generating a high temperature gas.

As the conventional liquid oxidant, liquid oxygen (LO ₂ ), dinitrogen tetroxide (N ₂ O ₄ ), a HAN aqueous solution, or the like is used.
Further, in the present application, “detonability” means a reactivity that causes a rapid pressure increase at the time of use as the steel tube ruptures in a detonator initiation test because the burning rate is very high (for example, about 450 mm / s). means.

    Monopropellant (one-component propellant) is a propellant that functions with only one component, and is disclosed in [Non-patent Document 1] [Patent Document 1] [Patent Document 2] and the like. Liquid oxidizers used for liquid propellants and hybrid propellants are disclosed in [Patent Document 3] [Patent Document 4] and the like.

  The “one-liquid propulsion method and one-liquid propulsion apparatus” of [Patent Document 1] uses a mixed liquid containing hydroxyammonium nitrate and fuel as the one-liquid propellant when the thrust is obtained by the one-liquid propellant. A part of the mixture is decomposed by a catalyst to generate high-temperature gas, and the remaining part of the mixed liquid is directly injected into the combustion space, and the directly injected mixed liquid is ignited and burned with high-temperature gas in the combustion space to generate thrust. To get.

  The HAN / HN-based monopropellant of [Patent Document 2] is composed of a HAN / HN mixed oxidant containing hydroxylammonium nitrate (HAN), hydrazinium nitrate (HN) and water and a fuel component.

  [Liquid oxidizing agent and hybrid propellant] of [Patent Document 3] is one or more selected from the group consisting of hydroxylammonium nitrate, hydrazinium nitroformate, ammonium dinitramide, ammonium nitrate, and hydrogen peroxide. Containing an oxidizing agent.

The “OXIDIZING AGENT” of [Patent Document 4] contains 5 to 30% by weight of ammonium nitrate (AN), 60 to 85% by weight of hydroxylammonium nitrate (HAN), and 10 to 25% by weight of water (H ₂ O ) Is a liquid oxidizing agent comprising an aqueous solution.

George P. Sutton, Rocket Propulsion Engineering, Sankaido, Chapter 8 Liquid Propellant

Japanese Patent Application Laid-Open No. 11-22555, “One liquid propulsion method and one liquid propulsion apparatus” Japanese Patent Application Laid-Open No. 2004-331425, “HAN / HN-based monopropellant and high-temperature gas generation method using the same” JP 2002-20191 A, “Liquid oxidizing agent and hybrid propellant” US Invention Registration No. H1768, “OXIDIZING AGENT”

    As disclosed in [Non-Patent Document 1], hydrazine, hydrogen peroxide, ethylene oxide, and nitromethane have been conventionally used as trials as monopropellants (one-component propellants). However, only hydrazine is currently in practical use because it is chemically and thermally stable, has good storage properties, is easily decomposed / reacted and has good combustion characteristics.

    However, hydrazine is highly toxic, and it is necessary to harden it with protective clothing during handling, which has a problem of poor handling.

Of the conventional liquid oxidizers, LO ₂ requires a cryogenic temperature retention and heat insulation mechanism, N ₂ O ₄ is extremely toxic and requires protective clothing similar to hydrazine, and HAN aqueous solution has a high burning rate, There is a danger of explosion and flashback.

On the other hand, liquid oxidizers (hereinafter referred to as “HAN-based liquid oxidizers”) in which hydroxylammonium nitrate (HAN), water (H ₂ O), ammonium nitrate (AN) and the like are mixed are already known.

    However, HAN-based liquid oxidizers have a very high burning rate (for example, about 450 mm / s) and so-called detonation, causing a sudden pressure increase during use, which may cause an emergency stop or damage to the catalyst. there were. Also, once ignited, the combustion continued without a catalyst and the combustion speed was very fast, so there was a case where the oxidant tank was flashed back in an instant.

    The present invention has been developed to solve the above-described conventional problems. That is, the object of the present invention is (1) low toxicity and easy handling, eliminating the need for protective clothing, etc. (2) no self-combustion without a catalyst, thereby preventing the risk of flashback and safety (3) Suppresses the burning rate, can be stably maintained at an appropriate pressure during use, thereby reducing the possibility of an emergency stop and damage to the catalyst, and (4) Comparing with conventional products The object is to provide a liquid oxidant, a propellant using the same, and a method for generating a high-temperature gas.

According to the present invention, hydroxylammonium nitrate (HAN) and hydrazinium nitrate (HN) are dissolved in water (H ₂ O), and further contain 1 to 10% by weight of fuel component. A liquid oxidant is provided.

According to a preferred embodiment of the present invention, the HAN content is 40 to 60% by weight, the HN content is 20 to 30% by weight, and the balance is water (H ₂ O) and fuel components.
Furthermore, the fuel component is preferably triethanolammonium nitrate (TEAN) or glycine.

  Moreover, according to this invention, the propellant characterized by consisting of the liquid oxidant mentioned above and solid fuel or liquid fuel is provided.

Preferably, the liquid fuel is a hydrocarbon fuel, and the solid fuel is HTPB or a GAP binder.
The propellant is preferably a hybrid rocket propellant or a two-liquid propellant.

  Further, according to the present invention, the above-described liquid oxidant and solid fuel or liquid fuel are stored separately, and mixed or brought into contact immediately before use to ignite and generate a high temperature gas. A method is provided.

The liquid oxidizer of the present invention described above has low toxicity, is easy to handle, and can eliminate the need for protective clothing.
In addition, the propellant composed of the liquid oxidizer and the solid fuel or the liquid fuel can also suppress the combustion rate and can be stably maintained at an appropriate pressure during use, thereby reducing the possibility of an emergency stop and damage to the catalyst.
Furthermore, in the structure of this invention, since the liquid oxidizing agent contained both HAN and HN components, it was confirmed by the test results described later that the responsiveness is high.

In the hot gas generation method of the present invention, since the liquid oxidant and the liquid fuel are stored separately, they do not self-combust independently, and even if ignited, there is no backfire, so safety is high.
Furthermore, liquid oxidizers containing both HAN and HN components are responsive and are used as liquid oxidizers for hybrid rockets, whether sprayed directly onto the catalyst or used as two-component propellants in combination with liquid fuel. Even in this case, high responsiveness can be expected.

  As described above, the liquid oxidant of the present invention, the propellant using the liquid oxidant, and the high-temperature gas generation method are (1) less toxic and easy to handle and can eliminate the need for protective clothing. ) No self-combustion without a catalyst, which makes it safe with no risk of backfire, and (3) Suppresses the combustion rate and can be stably maintained at an appropriate pressure during use. (4) It has excellent effects such as having performance comparable to conventional products.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to a common part and the overlapping description is abbreviate | omitted.

    FIG. 1 is a block diagram of a test apparatus for carrying out the method of the present invention. In this figure, 1 is a liquid oxidizer, 2 and 12 are pressurized gas tanks, 4 is a stock solution tank, 6a and 6b are solenoid valves, 7a, 7b, 17a and 17b are manual on-off valves, 8 is a reactor, and 11 is liquid fuel. , 14 is a liquid fuel tank, 15 is a mixing tank, P is a pressure measuring device, and T is a temperature measuring device.

The pressurized gas tanks 2 and 12 contain an inert gas (for example, N ₂ , Ar, and He) that does not react with the liquid oxidant 1 and the liquid fuel 11 at a pressure of, for example, 1 to 3 MPa, and manual open / close valves 7 a and 17 a are provided. The liquid oxidant 1 or the liquid fuel 11 in the tanks 4 and 14 is pressurized via the manual on-off valves 7b and 17b, and the liquid oxidant 1 and the liquid fuel 11 are supplied to the mixing tank 15 via the manual on-off valves 7b and 17b. A two-component propellant 13 is formed.
The formed two-liquid propellant 13 is pressurized and supplied to the electromagnetic valves 6a and 6b by the pressure of the pressurized gas tanks 2 and 12.

    In this example, the solenoid valves 6a and 6b are arranged in series, and by a control device (not shown), a continuous mode in which both are simultaneously opened and a pulse mode in which both are periodically opened for a short time are possible by interlocking the two solenoid valves. I have to.

    The reactor 8 reacts / decomposes the two-liquid propellant 13 to generate a high-temperature gas by an ignition method (not shown).

The liquid oxidizer 1 dissolves hydroxylammonium nitrate (HAN) and hydrazinium nitrate (HN) in water (H ₂ O), and further contains 10% by weight or less of a fuel component.
The composition of the liquid oxidant 1 has a HAN content of 40 to 60% by weight, a HN content of 20 to 30% by weight, and further contains water (H ₂ O) and a fuel component.
The fuel component is 1% by weight or more and less than 10% by weight of triethanolammonium nitrate (TEAN) or glycine. Other fuel components may also be included. Further, the composition can be changed by performance trade-off.
Therefore, there is a merit that a 1-liquid and 2-liquid tank can be shared.

    The liquid fuel 11 is a hydrocarbon fuel or the like, and the solid fuel is HTPB or a GAP binder.

  When a catalyst is used as the ignition method, it is preferably an iridium catalyst, but the present invention is not limited to this, and other well-known catalysts such as Pt and Pd can be used.

    FIG. 2 is a block diagram showing an example of a hybrid rocket used in the method of the present invention. As shown in this figure, the hybrid rocket includes an oxidant tank and a solid fuel. Note that a two-component liquid rocket engine may be used instead of the hybrid rocket.

In the method of the present invention using the apparatus described above, a liquid oxidizer comprising an aqueous solution in which hydroxylammonium nitrate (HAN) and hydrazinium nitrate (HN) are dissolved in water (H ₂ O), and a solid fuel or liquid Fuel is stored separately and mixed or contacted immediately before use to ignite and generate hot gas.
By this method, liquid oxidant and liquid fuel are stored separately and mixed or contacted immediately before use to ignite and generate high temperature gas, so each does not self-combust and does not backfire even if ignited temporarily. High safety.

(Detonability test of liquid oxidizer)
Even a liquid oxidizer that does not contain a fuel component may be detonable depending on the HN addition ratio.
In this example, four types (No. 1, 2, 3, 4) shown in Table 1 were prepared as the liquid oxidizer 1, and a detonation test known as a detonator initiation test was conducted. Of these, No. 4 is a liquid oxidizing agent of the present invention.
In the detonator initiation test, liquid oxidizer 1 is filled into a predetermined steel pipe, both ends are sealed, the internal liquid is ignited by an electric heating wire, and whether or not the steel pipe is ruptured is tested for detonation. . As a result, in all three tests, No. Nos. 1 and 2 do not rupture and are not explosive and safe (O in the table). It was confirmed that No. 3 always bursts and explodes and has low safety (× in the table).

  In addition, it was confirmed that the liquid oxidant (No. 4) did not rupture when HAN: HN = 2: 1, and it was safe without detonation (◯ in the table).

(Thruster test)
A thruster test was performed on the above four types (No. 1, 2, 3, 4) of the liquid oxidizer 1 under conditions with a catalyst. In the thruster test, the response time (sec) and the stability at the start-up due to the catalytic reaction were tested. The results are shown in Table 2.
From this result, it was found that even if HN was added, the response was not affected.

(Self-flammability test)
With respect to the three types (No. 1, 2, 4) of the liquid oxidizer 1 described above, the self-combustibility, the combustion rate, the pressure index, and the ignition limit pressure were measured under the conditions without a catalyst. The burning rate was measured under a pressure of 4 MPa. Further, the pressure index was measured from the ignition limit to a pressure of 4 MPa.

Table 3 summarizes the results of this test. From this result, the HAN / HN of the present invention to which some fuel components such as TEAN or GLYCINE are added (No. 4) has no self-flammability, and the piping from the tank to the combustion chamber (propellant conduit) ), It can be seen that there is no risk of backfire to the tank as in the prior art.
In other words, despite the fact that the response time, which is important for thruster performance, is almost the same, even if sudden heat or pressure is applied during operation, there is no risk of ignition and backfire, which indicates that safety is high. .
However, if a catalyst is present, it exhibits high responsiveness, and therefore, it is expected that not only a catalyst but also other suitable ignition methods or a combination of these and a catalyst can provide high performance as an oxidizing agent.

Table 4 summarizes the test results described above. This table provides a comprehensive comparison of conventional hydrazine and HAN based monopropellants and HAN / HN based liquid oxidants (HAN / HN oxidants with some fuel components) according to the present invention.
From this table, it can be seen that the HAN / HN-based liquid oxidizer according to the present invention has no toxicity, detonation and self-flammability, and high thruster performance (stability and responsiveness).
In particular, the liquid oxidizer of the present invention has very low detonability and self-flammability and is particularly excellent in safety. In addition, it can be seen that the monopropellant obtained by adding liquid fuel to this is particularly excellent in thruster performance (stability and responsiveness) without being explosive and self-combustible.

Table 5 shows the predicted performance for liquid rockets when using various liquid oxidants. Of these, up to four from the left are conventional examples, and the remaining one (fifth) is the liquid oxidizer of the present invention.
From this table, LO ₂ liquid oxygen has high performance but needs cryogenic storage, and HAN / HN oxidant improves performance over conventional HAN / AN oxidant, but is self-combustible (Table 3). The HAN / HN-based oxidizer (invention) has a 20% reduction in performance, but has a merit that it has no self-flammability and is safe (see Table 3).

Table 6 shows the predicted performance of the hybrid rocket when various liquid oxidants are used. Of these, up to five from the left are conventional examples, and the remaining one (sixth) is the liquid oxidizer of the present invention.
From this table, when the liquid oxidizer of the present invention is used in a hybrid, for example, the performance is 10% lower than that of the HAN / HN oxidizer, but it is safe as described above.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist of the present invention.

It is a block diagram of the test apparatus for enforcing the method of this invention. It is a block diagram which shows an example of the thruster used for the method of this invention.

Explanation of symbols

1 liquid oxidant,
2, 12 Pressurized gas tank, 4 Stock solution tank,
6a, 6b solenoid valve, 7a, 7b, 17a, 17b manual on-off valve,
8 Reactor, 11 Liquid fuel, 14 Liquid fuel tank, 15 Mixing tank

Claims (7)

Liquid oxidation characterized in that hydroxylammonium nitrate (HAN) and hydrazinium nitrate (HN) are dissolved in water (H ₂ O) and further contain 1 to 10% by weight of fuel component Agent. The HAN content is 40 to 60% by weight, the HN content is 20 to 30% by weight, and the balance is water (H ₂ O) and a fuel component. Liquid oxidizer.   The liquid oxidizer according to claim 1, wherein the fuel component is triethanolammonium nitrate (TEAN) or glycine.   A propellant comprising the liquid oxidant according to any one of claims 1 to 3 and solid fuel or liquid fuel.   The propellant according to claim 4, wherein the liquid fuel is a hydrocarbon-based fuel, and the solid fuel is HTPB or a GAP binder.   The propellant according to claim 4 or 5, wherein the propellant is a hybrid rocket propellant or a two-liquid propellant. A high-temperature gas characterized in that the liquid oxidant according to any one of claims 1 to 3 and solid fuel or liquid fuel are stored separately, and mixed or contacted immediately before use to ignite and generate a high-temperature gas. How it occurs.

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