CN1794247B - Determination method of toxic gas diffusion range of liquid rocket falling explosion - Google Patents

Abstract

This invention relates to a determination method for the diffusion sphere of the explosive gas of a liquid socket when falling including: 1, setting up a set of information system suitable for socket flying regions including: digitalizing landforms of flied regions and setting up a geographical information system, imaging the landform information of the geographical information system into an emission coordinate system to collect information of cities, roads, plants, schools and populations, initializing the weather information of the regions, positions and the flying time into an information system, determining the toxin grade information of a liquid socket propellant, 2, determining the diffusion sphere of the explosive gas at falling of the socket including the determination of the source strength of the propellant, the air wind field of a complicated landform and the diffusion concentration.

Description

Determination method of toxic gas diffusion range of liquid rocket falling explosion

Technical field

The present invention relates to a kind of definite method of definite liquid rocket falling explosion scope poison gas diffusion, is about the method for explosion of liquid rocket theoretical property and application combination, comprises the foundation of Geographic Information System, to determining of rocket falling explosion poison gas range of scatter.The increasing with the propellant consumption of increasing along with the satellites transmits task, emission test accidental detonation harmfulness, particularly to staff and satellites transmits approach region significant threat, this determines that method provides foundation for the evacuation of the resident launching site near, strick precaution search work when accident takes place.

Background technology

For determining of liquid propellant rocket falling explosion scope, all adopt the mode that contracts than experiment to carry out both at home and abroad, the U.S. once repeatedly carrier rocket contract than experiment, domesticly also once did experiment in the plains region at the liquid rocket propellant of low dose, but it is not higher than the experiment degree of confidence to contract, and only be applicable to the situation of rocket in launch-pad explosion, for rocket aloft the situation of falling explosion then can't determine.This definite method is data analysis by experiment, set up mathematical model, surveys QED one-tenth by the scene of the accident.

The content of invention

After the objective of the invention is to solve the liquid rocket propellant blast, definite method of toxic gas evaporation rate and the diffusion under complex-terrain, IFR conditions thereof, method comprises:

One, sets up the infosystem that a cover and rocket flight navigating area adapt

1, with the landform digitizing of rocket flight navigating area, sets up a cover Geographic Information System based on digitized terrain data;

2, the terrain information with Geographic Information System is mapped in the launching coordinate system, any one point (P of corresponding ground _k, b _k, H _k), all can determine its coordinate in launching coordinate system (x, y, z).Wherein: P _k, b _k, H _kBe respectively geodetic longitude, geodetic latitude, the earth elevation of certain point on the ground, x, y, z are respectively this 3 coordinate components in launching coordinate system;

3, city, road, factories and miness, school, the people information with the rocket flight navigating area is input in the Geographic Information System, be used for determining the region target that needs protection in the rocket flight process, fault take place the back determine the rocket falling explosion after the range of scatter and the extent of injury of poison gas;

4, with the meteorological data of rocket flight navigating area (U, T, α), the coordinate (x in the launching coordinate system ,Y, z), relative flight time t _qBe initialised in the infosystem, wherein: U is a mean wind speed, and T is an air absolute temperature, and α takes the direction of wind as the leading factor; Participate in the N of explosive combustion ₂O ₄Total amount W with the uns-dimethylhydrazine propellant ₀, for the known variables of input, by obtaining in the infosystem;

5, the terrain information with the rocket flight navigating area shows in conjunction with poison gas concentration on the range of scatter display system;

6, determine liquid rocket propellant toxicity grading information

Propellant is virulent to human body mainly to be that (molecular formula is N to dinitrogen tetroxide ₂O ₄, 30 minutes emergent, and to expose limit value be 20PPM) and uns-dimethylhydrazine (molecular formula is (CH ₃) ₂N ₂H ₂, be called for short uns-dimethylhydrazine, emergent exposure limit value was 50PPM in 30 minutes), the two is the conventional propellant that pairing is used, dinitrogen tetroxide is an oxygenant, and its boiling point lower (21.15 ℃) is in the environment that is placed on the temperature that is above the boiling point, flash at once, in being placed on the environment that is lower than boiling temperature, show as steady evaporation, therefore, differ manyfold in its boiling point malicious source strength up and down, so be incomparable at the poison gas concentration in two seasons of summer in winter; Uns-dimethylhydrazine is an incendiary agent, the product that reacts with dinitrogen tetroxide perfect combustion is nontoxic, the volume ratio of uns-dimethylhydrazine and air mixed was greater than 2% o'clock, light with regard to available naked light or electric spark, if in the rocket explosion accident, have air to be involved in, will cause the more than needed of dinitrogen tetroxide, and then cause the dinitrogen tetroxide poison source strength after the explosion accident big, permeate the uns-dimethylhydrazine in the earth of ground in addition, the burning on the face of land, the evaporation rate of ground deep layer is slow, so often in the back long period takes place in the rocket explosion accident, the concentration of detected uns-dimethylhydrazine has been zero, and the concentration of nitrogen tetraoxide is but quite big.The anhydrous hydrazine consumption is few, and the malicious source strength of explosion accident can be without a moment's thought.Liquid hydrogen in the rocket and liquid oxygen and reaction product thereof are nontoxic to personnel, so be not malicious source.

Two, determine rocket falling explosion poison gas range of scatter

1, determines poison gas evaporation rate after the liquid rocket propellant blast

Determine after the liquid rocket propellant blast the poison gas evaporation rate in two kinds of situation, when promptly taking place based on the propellant explosion accident environment temperature T (known) in boiling point situation up and down, corresponding flash speed and steady evaporation rate respectively.At first determine the propellant evaporation total amount.Determine the steadily initial rate of evaporation of propellant again, and then the steady evaporation rate of definite rocket after damp, determine rocket after damp flash speed at last.

(1) the propellant evaporation total amount is

W _f＝k _fW ₀

In the formula: k _fBe scale-up factor, determine, the propellant dinitrogen tetroxide is got 0.02028, the propellant uns-dimethylhydrazine is got 0.009566, W by the ratio of oxygen in the air and the chemical reaction of propellant explosion ₀For participating in the N of explosive combustion ₂O ₄With the total amount of the propellant of uns-dimethylhydrazine, by obtaining in the infosystem.

(2) propellant initial evaporation speed is by being

${\stackrel{\&CenterDot;}{W}}_{\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="H05157487820060116E000032.png"\; state="\{\{state\}\}">V</figure-callout>}0}=0.03305k_m{,m}_f{W}_{f}A$

In the formula:

For propellant initial evaporation speed, wait to ask.k _mBe the mass diffusion coefficient on gas surface, kilogram. mole/second. foot ², the experimental formula of the enough Gilliband of energy is determined; m _fFor the molecular wt on gas surface, known; W _fBe the propellant evaporation total amount, obtain by (1); A is that rocket blast back propellant more than needed reveals the area on empty surface, calculates according to experimental result, is known conditions.

(3) the steady evaporation rate of rocket after damp is

${\stackrel{\&CenterDot;}{W}}_{\mathrm{vt}}={\stackrel{\&CenterDot;}{W}}_{v0}{e}^{\frac{{\stackrel{\&CenterDot;}{W}}_{v0}}{W_f}t}$

In the formula:

For the steady evaporation rate of poison gas after the explosion of liquid rocket, wait to ask.

For propellant initial evaporation speed, obtain by (2); W _fFor propellant evaporation total amount more than needed in the fireball, obtain by (1).

(4) rocket after damp flash speed is

${\stackrel{\&CenterDot;}{W}}_{\mathrm{vt}}=\frac{{\mathrm{<figure-callout\; id="30"\; label="W\; f"\; filenames="H05157487820060116E000032.png"\; state="\{\{state\}\}">W</figure-callout>}}_f}{30}$

In the formula: For poison gas flash speed after the explosion of liquid rocket, wait to ask; W _fFor propellant evaporation total amount more than needed in the fireball, obtain by (1).

2, determine the wind field in the complex-terrain sky

For the equation after the liquid rocket propellant blast is carried out numerical integration, as forecast following CONCENTRATION DISTRIBUTION constantly, we know, the diffusion of concentration is that wind is finished, wind field is in diffusion equation is found the solution, be a very important input quantity, it is the basis that whole poison gas diffusion problem is found the solution.(u, v w) measure definite by weather radar or sounding balloon the wind field data.Wherein, (u, v w) are three wind vectors in the launching coordinate system.

3, determine the poison gas diffusion concentration

Determine the toxic gas diffusion process in atmosphere after liquid rocket propellant explodes, three wind vector (u in toxic gas rate of diffusion after obtaining propellant explosion, the launching coordinate system, v, w) after, separate the diffusion equation, draw time t toxic gas after the body propellant blast with launching coordinate system (x, y, diffusion concentration C z) _i, provide the concentration field data for range of scatter shows.The poison gas diffusion concentration is determined by diffusion equation (1).

Consideration is by M kind poison gas composition, the concentration C of every kind of poison gas composition _i(z t) can be determined by following conservation equation for x, y.

$\begin{array}{c}\frac{{\&PartialD;c}_i}{\&PartialD;t}+\frac{\&PartialD;}{\&PartialD;x}\left({\mathrm{uc}}_i\right)+\frac{\&PartialD;}{\&PartialD;y}\left({\mathrm{wc}}_i\right)+\frac{\&PartialD;}{\&PartialD;z}\left({\mathrm{wc}}_i\right)\\ =D_i(\frac{{\&PartialD;}^2{c}_i}{\&PartialD;x^2}+\frac{{\&PartialD;}^2{c}_i}{\&PartialD;{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="H05157487820060116E000041.png"\; state="\{\{state\}\}">y</figure-callout>}}^2}+\frac{{\&PartialD;}^2{c}_i}{\&PartialD;z^2})+R_i(c_i,T)+{\stackrel{\&CenterDot;}{W}}_{\mathrm{vt}}(x,y,z,t)...\left(1\right)\end{array}$

T is the time after the propellant blast in the formula, and is known; C _iBe the diffusion concentration of I kind poison gas composition, 1,000,000/volumetric concentration PPM waits to ask; D _iBe the molecular diffusivity of i kind poison gas composition, known; R _iBe the chemical reaction production rate of I kind composition,, known;

Be i kind poison gas composition poison gas evaporation rate, known; T is an absolute temperature, and (u, v w) are three wind speed components in the launching coordinate system, known variables; K _H, K _vFor the coefficient of diffusion of the earth level and the earth elevation, known.

4, range of scatter shows

Time t after obtaining the propellant blast, toxic gas are with launching coordinate system (x, y, diffusion concentration C z) _i, complex-terrain information data information input after, the CONCENTRATION DISTRIBUTION scope of utilizing MAPINFO geographic information processing instrument to provide as shown in Figure 8 on the matlab information processing platform shows.The poison gas concentration that can change with the geographic position in time after showing explosion of liquid rocket on the computer monitor and change distributes, and available click will check the poison gas concentration in place, with definite this place safety whether concerning personnel.Should determine that method adopted the information integration technology, display system and Geographic Information System were combined.The difficult point that generates electronic chart is the digitizing of landform, and we determine landform isoline data with visualization tool here, generates corresponding Drawing Object and show on Geographic Information System, has so just finished the digitizing of landform.

The scope of application of this definite method:

The poison gas concentration of emission place propellant explosion, burning, leakage accident is very big in the satellites transmits process, and place and maiden voyage district personnel's safety is constituted a serious threat.This method is when emission place and maiden voyage district personnel's evacuation, staff's emergency escape provided foundation with relevant gas protection when accident took place.

This method has solved the propellant problem of propellant blast under the complex-terrain, burning, leakage accident, this type of problem in plains region and open zone is that its one uses special case, therefore can the army of being widely used in inside and outside about and the problem of urban atmospheric pollution, thereby it has popularizing application prospect widely.

Description of drawings

Fig. 1 is a system integration synoptic diagram.

Fig. 2 is definite process of poison gas range of scatter.

Fig. 3 is certain blast photo of liquid rocket.

Fig. 4 is fireball diameter after the propellant explosion and time relation figure (the propellant explosion condition is that 136 kilograms of dinitrogen tetroxides add aerozine, leaks simultaneously).

Fig. 5 is fireball diameter after the propellant explosion and time relation figure (the propellant explosion condition is that 136 kilograms of dinitrogen tetroxides add aerozine, and oxygenant causes).

(test 1 meteorological condition is Fig. 6: temperature, 95 for the dinitrogen tetroxide concentration records figure of test 1 apart from 250 feet; Relative humidity, 17%; Average velocity, 2m/s).

(test 1 meteorological condition is Fig. 7: temperature, 102 for test 2 leeward concentration records figure; Relative humidity, 18%; Average velocity: 4m/s)

Fig. 8 is 35 minutes N2O4 CONCENTRATION DISTRIBUTION synoptic diagram after certain explosive incident, elevation is represented with change color wherein bigly, red representative is elevation the most highly and largely, bottom left section curve representation concentration level line among the figure, with arbitrfary point on the mouse-click figure, all can show its geography information and poison gas concentration value on the display system.

Embodiment

Validation test

(1) liquid rocket propellant blast large-scale experiment result verification

Test 1: leak simultaneously, fuel leak speed is 900 pounds of per seconds, N ₂O ₄Leak rate is 875 pounds of per seconds, and 300 pounds fuel draws off 1300 pounds N being less than 0.5 second ₂O ₄Draw off being less than 1.5 seconds, after two seconds, water is gone out with the speed of 100gallon/s, water rushes at the leakage disk center of catching fire, and at 1000 feet places, big several times blast can be heard, yet the blast registering instrument does not record superpressure, reaches 240 °F in angle iron frame place temperature.The poison gas vapour concentration of noting is very big, referring to Fig. 5.

Test 2: mix and leak, the condition of doing, flow velocity: fuel, 800 Pounds Per Seconds; Oxygenant, 1070 Pounds Per Seconds, the fireball of reaction has continued 10 seconds, and the blast instrument has write down superpressure 14 times, and the highest pulse appears at the 6th subpulse and has secondary decaying pulse, 445 of maximum temperatures, the poison gas vapour concentration is referring to Fig. 6.

Above test findings is consistent with top definite method.

(2) should determine method with the survey data checking of explosion of liquid rocket accident

To the carrying out of certain explosion of liquid rocket accident of satellites transmits place determine with this method validation, it is 8.2% that the data of the usefulness instrument detecting after density field distribution data of determining and the rocket explosion accident of satellites transmits place are answered the error of data, the precision that has proved the method for should determining satisfied satellites transmits place rocket explosion accident poison gas that take precautions against with requirement personnel's rescue.

The effect explanation

The method of should determining has been filled up domestic blank in this field, method content novelty, abundant, widespread use the experimental data of spending a large amount of funds just to obtain abroad, it determines that method gears to actual circumstances, workable, having strengthened the gassed safe precaution ability of satellites transmits process, is the make a strategic decision important evidence of safe prediction scheme of satellites transmits commander.Method taken precautions against at the rocket explosion accident poison gas of Chinese Xichang cosmodrome with personnel's rescue in be applied.

Should determine that method have the warning region of the toxic gas pollution that in advance provides contingent accident day part, and can quasi real time give poison gas that accidents happened produces poison gas dissipation situation in each protection zone.

Main technology feature:

(1) set up that the hurried evaporation speed of explosion of liquid rocket propellant, propellant are steadily evaporated speed and method is determined in time decay.

(2) advection of poison gas concentration diffusion equation is a kind of non-linear, non-conservation type Second Order Hyperbolic line equation, in the method for determining, effectively utilized the Gauss theorem, it is a rank equation that second-order equation is fallen, then a rank equation is transformed under the curve coordinate system, the method is suitable for the diffusion process of determining various ingredients, various source strengths.

(3) visual geographical information demonstration is combined with MAPINFO. With being presented in real time near the region of rocket blast of the poison gas diffusion scope after the liquid propellant blast.

Claims (1)

1. determination method of toxic gas diffusion range of liquid rocket falling explosion comprises:

(1), set up the infosystem that a cover adapts with the rocket flight navigating area, comprising:

1., with the landform digitizing of rocket flight navigating area, set up a cover Geographic Information System based on digitized terrain data;

2., the terrain information with Geographic Information System is mapped in the launching coordinate system any one point (P of corresponding ground _k, b _k, H _k), all can determine its coordinate in launching coordinate system (x, y, z); Wherein: P _k, b _k, H _kBe respectively geodetic longitude, geodetic latitude, the earth elevation of certain point on the ground, x, y, z are respectively this 3 coordinate components in launching coordinate system;

3., gather city, road, factories and miness, school, the people information of rocket flight navigating area;

4., with the meteorological data of rocket flight navigating area (U, T, α), the coordinate in the launching coordinate system (x, y, z), flight time t relatively _qBe initialised in the infosystem, wherein: U is a mean wind speed, and T is an air absolute temperature, and α takes the direction of wind as the leading factor; Participate in the N of explosive combustion ₂O ₄Total amount W with the uns-dimethylhydrazine propellant ₀, for the known variables of input, by obtaining in the infosystem;

5., the terrain information with the rocket flight navigating area shows in system in conjunction with the poison gas concentration range of scatter;

6., determine liquid rocket propellant toxicity grading information;

(2), the determining of rocket falling explosion poison gas range of scatter, comprising:

1., determine poison gas evaporation rate after the liquid rocket propellant blast

Determine evaporation rate in two kinds of situation, the situation of environment temperature T about boiling point when promptly taking place, corresponding flash speed and steadily evaporation rate respectively based on the propellant explosion accident;

2., determine the wind field in the complex-terrain sky

(u, v w) are measured by weather radar or sounding balloon and determine: wherein, (u, v w) are three wind vectors in the launching coordinate system to the wind field data;

3., determine the poison gas diffusion concentration

At first determine the toxic gas diffusion process in atmosphere after liquid rocket propellant explodes, the poison gas evaporation rate after obtaining propellant explosion

Three wind vectors in the launching coordinate system (u, v, w) after, by diffusion equation, draw time t toxic gas after the liquid rocket propellant blast with launching coordinate system (x, y, diffusion concentration C z) _i, provide the concentration field data for range of scatter shows;

4. dinitrogen tetroxide, range of scatter show

Time t toxic gas after obtaining the propellant blast is with launching coordinate system (x, y, diffusion concentration C z) _i, terrain information input after, provide N ₂O ₄The CONCENTRATION DISTRIBUTION areal map, and show that the poison gas concentration that changes with the geographic position in time after the explosion of liquid rocket and change distributes, and available click to check the poison gas concentration in place, with definite this place safety whether concerning personnel.

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