JPWO2006126397A1 - Two-component liquid propellant, flying object propulsion method and propulsion device - Google Patents

Abstract

Provided are a two-component liquid propellant that can perform ignition combustion without using a catalyst, a flying object propulsion method, and a propulsion device. As the two-component liquid propellant, one or two or more kinds selected from an aqueous hydroxylammonium nitrate solution as an oxidizing agent and an ether as a fuel are used. In the flying object propulsion method, a part of the liquid propellant is converted into plasma and gasified at a high temperature, mixed with the remainder of the liquid propellant by a constructor, ignited and burned, and the propelling force is obtained by discharging the combustion gas from a nozzle.

Description

  The present invention relates to a two-component liquid propellant for use in a propulsion device mounted on an aircraft such as an artificial satellite, an aircraft propulsion method, and a propulsion device.

  Currently, small propulsion devices (thrusters) mounted on artificial satellites are hydrazine or hydrazine that can be stored for a long period of time and have good ignition performance with a catalyst such as an iridium catalyst used to decompose the propellant. Generally, a one-component propellant composed of a mixture of derivatives is used as a propulsion source (for example, see Non-Patent Document 1). Here, the hydrazine derivative is asymmetric dimethylhydrazine (UDMH) or monomethylhydrazine (MMH). The one-component propellant refers to a single substance or a mixture of liquids that generate a high-temperature gas by reacting by catalytic action, heating, pressurization, or the like.

  However, hydrazine is very toxic and requires special attention in its handling, so there is a problem that work efficiency becomes extremely poor.

Therefore, as a new low toxicity propellant that replaces hydrazine, use of a HAN one-component propellant that can be ignited by a catalyst like hydrazine has been studied (for example, see Patent Document 1). Here, HAN means hydroxylammonium nitrate (Hydroxyl
(Ammonium Nitrate) is an abbreviation for HAN, and HAN is a mixture of water and triethanolammonium or alcohol.
HAN-based one-component propellants can be stored for a long time, have low toxicity, and have higher performance than hydrazine one-component propellants.
JP 2004-331425 A Ichiro Kimura, Rocket Engineering, 227, Yokendo, (1993)

  However, the conventional HAN-based one-component propellant has a problem that the ignition performance by the catalyst is poor, and the combustion temperature is high, so that the catalyst is easily deteriorated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a two-component liquid propellant that can be ignited by a method other than a catalyst, a flying object propulsion method, and a propulsion device.

  The two-component liquid propellant according to the present invention is characterized by using a hydroxylammonium nitrate aqueous solution as an oxidizing agent and one or more selected from ethers as a fuel.

  The two-component liquid propellant according to the present invention is characterized in that the ether is dimethyl ether.

  Further, the aircraft propulsion method according to the present invention provides energy to a part of the liquid propellant using hydroxylammonium nitrate as the oxidizer and one or more selected from ethers as the fuel. It is characterized in that it is supplied into a high-temperature gas, mixed with the remainder of the liquid propellant in a constructor, ignited and burned, and a propelling force is obtained by discharging the combustion gas from a nozzle.

  In addition, the flying object propulsion method according to the present invention is characterized in that a part of the liquid propellant is turned into plasma by arc discharge to supply energy.

  In addition, the flying object propulsion method according to the present invention is characterized in that at least the fuel of the propellant is pumped to the combustion chamber using the vapor pressure of the propellant fuel.

  The propulsion device according to the present invention is a propulsion device including a plasma jet generation unit, a combustion chamber provided in connection with the plasma jet generation unit, and a nozzle provided in connection with the combustion chamber. The plasma jet generator is a volatile fuel in a liquid propellant using hydroxylammonium nitrate as an oxidant in the upstream space and one or more selected from ethers as fuel. And a second introduction port for introducing the remaining portion of the liquid propellant into the constrictor.

  The two-component liquid propellant according to the present invention uses hydroxylammonium nitrate as the oxidant and one or more selected from ethers as the fuel, respectively, and the vehicle propulsion according to the present invention The method supplies energy to a part of the liquid propellant, decomposes the liquid propellant and gasifies it at high temperature, mixes with the rest of the liquid propellant, ignites and burns, and discharges the generated combustion gas from the nozzle Therefore, the propellant can be ignited and burned without using a catalyst.

It is a model figure of the propulsion machine used for the ignition test of the Example. It is a figure which shows the relationship between an energy supply ratio and driving force performance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anode 2 Cathode 3 Discharge power supply device 4 1st introduction path 5 Constructor 6 2nd introduction path 7 Combustion chamber 8 Pressure measurement port 9 Propulsion machine 10 Cooler 11 Nozzle

A preferred embodiment of the present invention will be described below.
First, the two-component liquid propellant according to the present invention will be described below.
The two-component liquid propellant according to the present invention is one or two selected from a hydroxylammonium nitrate aqueous solution (hereinafter sometimes referred to as HAN aqueous solution) as an oxidizing agent and an ether as a fuel. Use more than seeds, respectively.
Here, the two-component type is used in comparison with the one-component type, and separately supplies an HAN aqueous solution that is an oxidant and an ether that will be described later as a fuel, and mixes them in a combustion chamber to perform ignition.

Since HAN as an oxidant has a property of dissolving in water to a very high concentration, it can be handled as a liquid oxidant, and the concentration is preferably 80 to 88% by mass. Because, if the HAN concentration is too high, HAN will precipitate when impact or pressure is applied to the aqueous solution, and the solution will become unstable. Conversely, if the HAN concentration is too low, the water in the solution will increase. This is because the propulsion performance is lowered. However, this does not limit the concentration range of the HAN aqueous solution used for the propellant.
Since HAN has a low vapor pressure, it is handled in a liquid state when stored in a tank or when introduced into a propulsion unit.

Ethers as the fuel are not particularly limited, and examples thereof include dimethyl ether, ethyl methyl ether, diethyl ether, and ethyl vinyl ether. Among these, dimethyl ether and ethyl methyl ether which are in a gaseous state at normal temperature and pressure are preferable, and dimethyl ether having a boiling point as low as −24.8 ° C. (hereinafter sometimes referred to as DME) is more preferable.
If necessary, natural gas or petroleum gas may be used as fuel.

  The ethers are stored in a tank or the like in a liquefied state in a propulsion unit, for example, at a temperature of 25 ° C. and a pressure of 0.6 MPa, and are used.

  The ratio of HAN to ethers is preferably near the chemical equivalent ratio from the viewpoint of obtaining a high calorific value. However, in operation as a propellant, the ratio can be selected in a wide range, for example, HAN / ethers (molar ratio) = 1.5-3.

For example, the stoichiometric reaction formula when HAN is used as the oxidant and DME is used as the fuel is as follows.
C ₂ H ₆ O + 3NH ₃ OHNO ₃ → 2CO ₂ + 9H ₂ O + 3N ₂
(1)
The stoichiometric ratio of DME and HAN in the above reaction formula (1) is a mass ratio, as shown in the following formula (2).
DME: HAN = 13.8: 86.2 (2)

Next, the aircraft propulsion method according to the present invention will be described below.
The flying object propulsion method according to the present invention supplies energy to ethers, which are volatile fuels among liquid propellants, to produce high-temperature gas, and mixes the generated high-temperature gas with the rest of the liquid propellant in the constructor. Then, it is ignited and combusted, and a propelling force is obtained by discharging combustion gas (combustion product gas) from the nozzle.
In the flying object propulsion method according to the present invention, the liquid propellant can preferably use the above-described two-component liquid propellant according to the present invention, but is not limited thereto, for example, HAN / LNG, HAN / LPG A liquid propellant such as can also be used.
Hereinafter, the case where the two-component liquid propellant according to the present invention is used will be described as an example.

Here, a propulsion device according to the present invention that can be suitably used in the flying object propulsion method according to the present invention will be described with reference to FIG.
The propulsion device 9 includes a plasma jet generator, a combustion chamber 7 provided in connection with the plasma jet generator, and a nozzle 11 provided in connection with the combustion chamber 7.
The plasma jet generating section has an upstream space formed in a substantially cone shape that shrinks toward the constructor (nozzle throat) 5 on the upstream side (right side in FIG. 1). A first inlet 4 is provided which communicates with the upstream space of the plasma jet generator and introduces DME which is a volatile fuel of the propellant. The plasma jet generating unit is for discharge that applies a high voltage between the anode 1, the cathode 2 extending in the upstream space toward the constructor 5 at the center side of the anode 1, and the anode 1 and the cathode 2. And a power supply device 3. The plasma jet generator has a second inlet 6 that communicates with the constructor 5 and introduces the remaining portion of the propellant. In FIG. 1, reference numeral 8 indicates a pressure measuring port. Further, the cooler indicated by reference numeral 10 in FIG. 1 is provided as a safety measure for the experimental apparatus, and is not essential in the actual machine.
The anode 1 and the cathode 2 are each formed of, for example, tungsten, molybdenum, or carbon. The discharge power supply device 3 performs discharge under a discharge condition of about 3 kW or less, for example.

The first inlet 4 is connected to a tank that stores DME via a control valve (not shown). Since DME has a high vapor pressure, it can be introduced into the first inlet 4 without using a pressurizing means. The DME in the tank is maintained in a pressure of 0.6 MPa and a temperature of 298 K, for example, and is in a liquid state.
The second introduction path 6 is connected to a tank for storing HAN via a control valve (not shown). The HAN aqueous solution is pressurized by DME, and the HAN aqueous solution is supplied from the second introduction path 6 into the constructor 5 with this vapor pressure. HAN in the tank is in a liquid state, for example, maintained at a pressure of 0.1 MPa or less at a temperature of 298K. Since DME has a high vapor pressure, it can be introduced into the first introduction path 4 without using a pressurizing means. The HAN aqueous solution is pressurized by DME, and is supplied from the second introduction path 6 with this vapor pressure. Further, a part of each of HAN and DME may be supplied to each of the first introduction port 4 and the second introduction path 6.
In addition, when using a relatively high boiling point compound other than ether, such as ethanol and methanol, in other words, a compound having a low vapor pressure as the propellant, if necessary, the propellant is supplied to the nozzle space. For example, a pressurizing means such as a tank for pressurizing a propellant such as He is provided.

  The aircraft propulsion method according to the present invention gasifies a part of liquid propellant, in this case, DME, through a control valve in the space of the anode 1 and the cathode 2 of the plasma jet generator under a pressure close to vacuum. And supplied from the first introduction path 4. At this time, the DME stored in the high pressure state is jetted into the space portion of the plasma jet generating portion with its own pressure.

  In the space between the anode 1 and the cathode 2 of the plasma jet generating part, energy is supplied to the vaporized gas of the DME, and the vaporized gas is gasified at a high temperature.

At this time, arc discharge is preferably used as means for supplying energy and gasifying a part of the liquid propellant at a high temperature. Thereby, a part of liquid propellant can be made into high temperature gas of about several thousand K, for example. However, the present invention is not limited to this, and an appropriate means such as a high frequency discharge that can exhibit a thermochemical effect may be used. Here, the thermochemical effect means an effect of increasing the reaction rate because radicals contained in the plasma increase the reaction rate and the plasma itself is very high temperature.
For example, a DC power supply device used in an arc welding machine can be used as the arc discharge power source.
The plasma-formed DME is gas-jetted by the constructor 5 due to the thermal pinch effect. On the other hand, the remaining portion of the liquid propellant is supplied from the second inlet 6 into the constructor 5. In the above two-component configuration, the balance of the liquid propellant is an HAN aqueous solution. In the combustion chamber, the propellant is ignited and burned by the thermochemical effect of the plasma. The generated combustion gas is ejected to the outside through a nozzle to obtain a propulsive force.

  According to the two-component liquid propellant and the flying object propulsion method and the propulsion device according to the present invention described above, the catalyst for igniting the propellant is used without igniting and burning by the high temperature gas to obtain propulsion Ignition combustion can be performed.

  Further, the flying object propulsion method and the propulsion unit according to the present invention operate and change the specific thrust of the propulsion unit by continuously supplying energy to a part of the propellant from the outside even after the propellant is ignited. be able to. In addition to the reaction heat obtained from the propellant, the combustion gas obtained from the outside by a method such as discharge is in a higher enthalpy state than the combustion gas obtained only from the reaction heat. The specific thrust is improved compared to the latter.

(Example 1)
The propellant ignition test using a combination of HAN aqueous solution (HAN concentration 83.6% by mass) as the oxidizer and DME as the fuel was performed using the prototype propulsion unit shown in Fig. 1, and the chemical equivalent ratio and discharge power were measured for each experiment. It was done while changing the conditions every time.
Here, the HAN aqueous solution was prepared by dropping 60% by mass nitric acid while adjusting the dropping rate of nitric acid so as to keep the reaction temperature at about 5 ° C. while cooling and stirring the 50% by mass hydroxylamine aqueous solution, After the reaction, the water in the reaction solution was adjusted so that HAN had the above concentration (83.6% by mass). Here, commercially available reagents were used for hydroxylamine, nitric acid, and DME.
The prototype propulsion device applies an arc discharge at a discharge power of 2.5 kW / H between the nozzle-like anode 1 and the cathode 2 by the discharge power supply device 3, thereby having its own vapor pressure from the fuel supply port 4. The DME fed and fed by is heated. When the DME arc jet in a high enthalpy gas state obtained by heating was mixed with the HAN aqueous solution supplied at the vapor pressure of the DME from the oxidant supply port 6 in the constructor 5, the propellant was ignited. This was confirmed in the combustion chamber 7. At this time, the flow rate of the HAN aqueous solution was 7.5 mL / min, the flow rate of DME was 7.5 NL / min, the chemical equivalent ratio φ = 1, and the combustion chamber pressure measured from the pressure measurement hole 8 was about 0.2 MPa. It was.

(Example 2)
By performing chemical equilibrium calculations, changes in propulsion unit performance due to external energy addition were analyzed. The propulsion device performance was evaluated using the indices of the combustion chamber temperature Tc, the characteristic exhaust speed C *, the thrust coefficient Cf, and the specific thrust Isp.
The analysis results are shown in FIG. In FIG. 2, the horizontal axis represents the ratio (input power amount / propellant theoretical heat value) R of the external energy addition (input power amount: unit kW) to the propellant theoretical heat value (unit kW), and the vertical axis In addition, each index of propulsion device performance was taken. At this time, combustion chamber pressure Pc = 0.4 MPa, outlet pressure Pe = 0.01 MPa, Pc / Pe = 40, nozzle throat diameter Dt = 3 mm, chemical equivalent ratio φ = 1, HAN: water = 80 weight: 20 weight Condition. 2 that the combustion chamber temperature Tc, the characteristic exhaust speed C *, and the specific thrust Isp increase as the input power amount or input power ratio increases.

Claims (6)

  A two-component liquid propellant characterized in that an aqueous hydroxylammonium nitrate solution is used as an oxidizing agent and one or more selected from ethers are used as a fuel.   The two-component liquid propellant according to claim 1, wherein the ether is dimethyl ether.   An aqueous solution of hydroxylammonium nitrate as an oxidant and one or more selected from ethers as a fuel are supplied to a part of the liquid propellant used to gasify it at a high temperature, and the liquid propellant A flying object propulsion method characterized in that the remaining part of the vehicle is mixed and ignited and burned in a constrictor to obtain propulsive force by discharging combustion gas from a nozzle.   4. The aircraft propulsion method according to claim 3, wherein a part of the liquid propellant is turned into plasma by arc discharge to supply energy.   The method for propelling an air vehicle according to claim 3, wherein at least fuel of the propellant is pumped to the combustion chamber by using a vapor pressure of the propellant fuel. A propulsion device comprising a plasma jet generator, a combustion chamber provided connected to the plasma jet generator, and a nozzle provided connected to the combustion chamber,
Volatile fuel among liquid propellants in which the plasma jet generator uses an aqueous solution of hydroxylammonium nitrate as an oxidizing agent in the upstream space and one or more selected from ethers as fuel. A propulsion device comprising: a first introduction port for introducing gas; an arc discharge portion for performing arc discharge in the upstream space; and a second introduction port for introducing the remainder of the liquid propellant into the constructor. .

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