A method for estimating the transportation safety of flattened pellets with high plasticizer content under heat and vibration

Abstract

The present invention discloses a method for predicting the transportation safety of spherical oblate propellant with a high plasticizer content under heat and vibration. The method first conducts heat aging treatment on the spherical oblate propellant with a high plasticizer content; then conducts seven heating and vibration tests on the samples; furthermore, obtains the volume content of decomposition gas CO2 and the volume content of N2O of the spherical oblate propellant with a high plasticizer content in each sample cup after each heating and vibration test, and finally obtains the relationship curve between the number of heating and vibration tests and the volume content of CO2 for each sample, as well as the relationship curve between the number of heating and vibration tests and the volume content of N2O; evaluates the transportation safety of the spherical oblate propellant with a high plasticizer content according to the obtained curves. The method of the present invention can predict the transportation safety of the newly developed spherical oblate propellant with a high plasticizer content after long-term storage expires, and can also compare the transportation safety of the spherical oblate propellant with a high plasticizer content produced by different processes after long-term storage expires.

Description

Technical Field

[0001] The invention belongs to the field of physical and chemical detection of explosives, and in particular relates to a method for estimating the transportation safety of flat spherical explosives with high plasticizer content under heat and vibration. Background Art

[0002] At present, most of the commonly used gun charges are double-base spherical flat propellants, which are one of the varieties of double-base propellants. The safety of double-base propellants refers to the sensitivity of double-base propellants to combustion or explosion caused by various external excitation energy sources (such as impact, friction, static sparks, heat, shock waves, etc.).

[0003] In addition to chemical changes that lead to poor chemical stability, double-base propellants that have been stored for a long time also experience some physical changes. During transportation, the more insensitive double-base propellants are to the various excitation energies they may encounter, the better. For double-base propellants with high plasticizer content, during long-term storage, "sweating" will occur due to the migration of plasticizers such as nitroglycerin. The "sweating" nitroglycerin decomposes under heat, and the NO produced X It cannot be absorbed by the stabilizer inside the propellant, and plays a catalytic role in the chemical decomposition of the propellant. "Sweating" is a physical phenomenon. The physical change caused by the migration of plasticizers causes chemical changes, which increases the danger. Especially when the expired propellant is transported, in addition to thermal stimulation, the vibration causes the propellant particles to rub and impact the nitroglycerin, which deteriorates the transportation safety of expired double-base propellants.

[0004] The existing test methods used to determine whether expired propellants are safe for transportation have the following problems when evaluating the safety of newly developed high-plasticizer-content spherical propellants:

[0005] (1) It is not possible to estimate the transportation safety of newly developed high-plasticizer-content spherical propellants after long-term storage, and it is not possible to compare the transportation safety of high-plasticizer-content spherical propellants produced with different compositions, proportions and processes after long-term storage.

[0006] (2) The damage that the “sweat-out” plasticizer may cause to the safety of expired drugs during transportation was not considered.

[0007] (3) Only the effects of heat or vibration (friction, impact) as a single stimulus energy on the transportation of expired propellants are investigated. The test results of heat or vibration as a single stimulus energy cannot accurately represent the actual situation of expired propellants during transportation. Summary of the invention

[0008] In order to solve the deficiencies in the prior art, the present invention provides a method for estimating the transportation safety of a high-plasticizer-content propellant under heat and vibration, so as to achieve the estimation of the transportation safety of a high-plasticizer-content propellant.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0010] The present invention discloses a method for estimating the transportation safety of a high-plasticizer-content flattened spherical drug under heat and vibration, comprising the following steps:

[0011] Step 1, placing a plurality of sample storage cups filled with high-plasticizer content spherical flat medicine samples into a solid sample block, and then placing the solid sample block into an oven for heating aging treatment and then naturally cooling to room temperature;

[0012] Step 2, obtaining the CO2 content of the gas in the empty sample storage cup;

[0013] Step 3, performing a heating vibration test up to 7 times on the sample storage cup containing the sample obtained in step 1; obtaining the CO2 volume content and N2O volume content of the gas in each sample storage cup after each heating vibration test, and then obtaining the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical flattened charge in each sample storage cup after each heating vibration test;

[0014] Step 4, plotting the number of heating vibration tests as the horizontal axis and the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical flattened charge as the vertical axis, respectively, to obtain a relationship curve between the number of heating vibration tests and the CO2 volume content of each sample, and a relationship curve between the number of heating vibration tests and the N2O volume content;

[0015] Step 5: Based on the curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of N2O obtained in step 4, the transportation safety of the high plasticizer content spherical flattened powder is evaluated, specifically including:

[0016] If the acute angle θ between the line segment obtained by connecting two adjacent CO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the CO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the first heating vibration number limit value of the sample;

[0017] If the acute angle θ between the line segment obtained by connecting two adjacent NO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the NO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the second heating vibration number limit value of the sample;

[0018] Compare multiple first heating vibration number limit values ​​and / or second heating vibration number limit values ​​of each sample, and use the heating vibration number value with the smallest value as the safe transportation days of the high plasticizer content flattened spherical drug;

[0019] If the obtained curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of NO2 do not show any sudden changes, it is determined that the safe transportation days of the high plasticizer content spherical flattened bullet are greater than 7.

[0020] The present invention also has the following technical features:

[0021] Specifically, the heating temperature of the heat aging treatment is 83-87° C., and the aging time is 20-30 days.

[0022] Furthermore, the heating temperature of the heating vibration test is 70-72° C., the vibration time is 7-9 hours, the vibration frequency is 9 Hz-11 Hz, and the amplitude is 15 mm-25 mm.

[0023] Furthermore, the volume content of CO2 in the decomposition gas of the high plasticizer content spherical flattening charge in step 3 = the volume content of CO2 in the sample storage cup measured after the heating and vibration test - the volume content of CO2 in the gas in the empty sample storage cup; the volume content of N2O in the decomposition gas of the high plasticizer content spherical flattening charge = the volume content of N2O in the sample storage cup measured after the heating and vibration test.

[0024] Furthermore, the filling mass of the high plasticizer content spherical pill in the sample cup is 9.9 g to 10.1 g.

[0025] Furthermore, in the step 4, the number of heating vibration tests is 0 to 7 times as the horizontal axis, and the CO2 volume content of 0 to 4.0% and the N2O volume content of 0 to 0.5% of the decomposition gas of the high plasticizer content spherical protrusion are used as the vertical axis to draw a graph, and the length corresponding to the maximum value of the horizontal axis is equal to the length corresponding to the maximum value of the vertical axis.

[0026] Furthermore, two parallel samples are made for each propellant sample for heating vibration test. After a sudden jump occurs in the relationship curve between the heating vibration test number and the CO2 volume content or the relationship curve between the heating vibration test number and the N2O volume content of any parallel sample, the two parallel samples will no longer be subjected to subsequent heating vibration tests.

[0027] Furthermore, the method is implemented by using a high-plasticizer content flattened pill transportation safety test device, the device comprising a sample storage cup, a fixing block and a heating device; the sample storage cup comprises a cup cover and a cup body; a one-way air inlet valve and a through air sampling hole are arranged on the upper surface of the cup cover, and a sealing pad and an adsorption pad are arranged in the cup cover from top to bottom in sequence;

[0028] The solid sample block is provided with a plurality of lofting holes with open tops at equal angle intervals along the circumference, a first positioning hole penetrating from top to bottom is provided at the center of the solid sample block, and a plurality of second positioning holes penetrating from top to bottom are also provided at equal angle intervals along the circumference on the solid sample block, and the lofting holes and the second positioning holes are alternately arranged along the circumference of the upper surface of the solid sample block

[0029] The heating device includes a heating mechanism and a heating box arranged above the heating mechanism; the heating box includes a box cover and a box body, a heating cavity with an open top is arranged in the box body, a first positioning rod that can be plugged into and matched with a first positioning hole, and a second positioning rod that can be plugged into and matched with a second positioning hole are arranged in the heating cavity.

[0030] Furthermore, the one-way air inlet valve, the air collection hole and the center of the cup cover are arranged on the same line.

[0031] Furthermore, the sample fixing block is cylindrical, the number of the layout holes is 6, the distance between the center of the layout hole and the center of the first positioning hole is 40 mm, the layout hole includes a first inner cavity and a second inner cavity connected from top to bottom, and the diameter of the first inner cavity is greater than the diameter of the second inner cavity.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The method of the present invention can estimate the transportation safety of newly developed spherical propellants with high plasticizer content after long-term storage expires, and can also compare the transportation safety of spherical propellants with high plasticizer content produced by different compositions, proportions and processes after long-term storage expires. With the help of the method of the present invention, technicians can optimize the proportion and improve the process of spherical propellants with high plasticizer content.

[0034] (2) The method of the present invention not only considers the impact of chemical changes of high plasticizer content propellant after long-term storage on transportation safety, but also considers the impact of physical changes such as plasticizer migration during long-term storage on the transportation safety of propellant after long-term storage, and can accurately characterize the actual situation of expired propellant during transportation.

[0035] Other advantages of the present invention are described in detail in the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the structure of a sample storage cup according to embodiment 1 of the present invention;

[0037] Figure 2 is a top view of a solid sample block according to Embodiment 1 of the present invention;

[0038] Figure 3 is a cross-sectional view of a solid sample block according to Embodiment 1 of the present invention;

[0039] Figure 4 is a schematic structural diagram of a heating device according to Embodiment 1 of the present invention;

[0040] Figure 5 The relationship curve between the heating vibration test times and the CO2 volume content of the three samples in Application Example 1 of the present invention;

[0041] Figure 6 This is the relationship curve between the number of heating vibration tests and the volume content of CO2 of sample 3#-1 in Application Example 1 of the present invention;

[0042] Figure 7 Relationship curve between the heating vibration test times and N2O volume content of the three samples in Application Example 1 of the present invention;

[0043] Figure 8 This is the relationship curve between the heating vibration test times and the N2O volume content of the 3#-1 sample in Application Example 1 of the present invention;

[0044] Fig. 9 This is the relationship curve between the number of heating vibration tests and the volume content of CO2 of the four samples in Application Example 2 of the present invention;

[0045] Fig.10 is the relationship curve between the heating vibration test times and the CO2 volume content of the A-1 sample in Application Example 2 of the present invention;

[0046] Fig.11 is a curve showing the relationship between the number of heating vibration tests and the volume content of N2O of the four samples in Application Example 2 of the present invention;

[0047] Fig.12 is the relationship curve between the heating vibration test times and the N2O volume content of the B-2 sample in Application Example 2 of the present invention;

[0048] Description of the symbols in the figure:

[0049] 1-sample storage cup, 2-solid sample block, 3-heating device, 4-first positioning rod, 5-second positioning rod; 11-cup cover, 12-cup body, 13-sealing pad, 14-adsorption pad; 21-sample placement hole, 22-first positioning hole, 23-second positioning hole; 31-heating mechanism, 32-heating box, 111-one-way air inlet valve, 112-gas sampling hole; 211-first inner cavity, 212-second inner cavity; 321-box cover, 322-box body. DETAILED DESCRIPTION

[0050] The following are specific embodiments of the present invention. It should be noted that, in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integrated connection; it can be a direct connection or an indirect connection, etc. For ordinary technicians in this field, the specific meanings of the above terms in this technical solution can be understood according to specific circumstances.

[0051] The present invention is not limited to the following specific embodiments. The specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. As long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

[0052] Expired propellants can be transported by road or rail. Relatively speaking, the higher flexibility of road transportation makes it more suitable for the transportation of dangerous goods, so this application focuses on the safety of road transportation.

[0053] The transportation time of expired propellant by road is generally no more than 7 days. The main excitation energy sources of propellant are heat, moisture, vibration, etc. Analysis shows that expired propellant is wrapped in multi-layer packaging. There will not be much moisture penetrating the packaging and directly contacting the propellant within 7 days, so moisture as an excitation energy source is excluded. During transportation, the open-air ambient temperature may be as high as 50°C or above. If it is directly exposed to sunlight, its surface temperature can reach more than 70°C. The increase in temperature can increase the chemical reaction rate of nitrocellulose and nitroglycerin. In general, the chemical reaction temperature coefficient of explosives is r 10 =3~4, that is, for every 10℃ increase in temperature, the time required to reach the same degree of reaction will be shortened by 3~4 times. Therefore, it is necessary to consider the excitation energy of heat. On the other hand, due to the vibration caused by the complex road conditions, friction and extrusion will occur between the pellets of spherical oblate propellant, which will be converted into heat energy, increasing the hot spots of the propellant, and the hot spots can increase the chemical decomposition rate of the propellant. In addition, the nitroglycerin "sweat" is highly sensitive, and the pellets will rub and collide with the nitroglycerin due to vibration. Therefore, it is necessary to consider the excitation energy of vibration. Therefore, when determining the safety of transportation of expired spherical oblate propellants, the main excitation energy is heat and vibration.

[0054] The particle size of the high plasticizer content spherical drug of the present invention is between 0.4 mm and 1.1 mm, the plasticizer contained is an energetic substance, and the content of the plasticizer is ≥30%.

[0055] Example 1

[0056] This embodiment discloses a method for estimating the transportation safety of a high-plasticizer-content flattened pellet under heat and vibration, which is characterized by comprising the following steps:

[0057] Step 1, placing a plurality of sample storage cups filled with high-plasticizer content spherical flat medicine samples into a solid sample block, and then placing the solid sample block into an oven for heating aging treatment and then naturally cooling to room temperature;

[0058] Preferably, two parallel samples are prepared for each propellant sample for the heating vibration test;

[0059] When determining the weight of a single sample, the following aspects should be considered:

[0060] a. The sample weight is too small, and the decomposition gas produced by the propellant when heated is too little, which may be below the detection limit of gas chromatography and cannot be detected;

[0061] b. The sample weight is too large, and the propellant decomposes too violently due to factors such as heat accumulation. Especially for spherical oblate propellants with high plasticizer content after aging, too large a sample weight poses a greater safety hazard;

[0062] c. The smaller the sample weight of a single test specimen, the more samples can be tested and the higher the detection efficiency.

[0063] Finally, the sample weight of a single sample was determined to be 10g. Since the particle size of the spherical oblate propellant is small, the sample weight range was determined to be 9.9g to 10.1g.

[0064] It should be noted that the degree of accelerated aging and operating conditions of the samples are determined to make the newly produced propellant samples become expired in long-term storage. The purpose of accelerated aging of samples is to make the samples undergo changes equivalent to those that occur in natural long-term storage for many years in a relatively short period of time in the laboratory.

[0065] If the degree of accelerated aging is too large, the physical changes of different propellants will reach the extreme, which is not conducive to detecting the difference between different propellants. If the degree of accelerated aging is too small, different propellants are in a stage of good stability and safety, and it is also difficult to detect the difference between different propellants. Therefore, the degree of accelerated aging should not be too large or too small.

[0066] The typical change of stabilizer content in double-base propellants during long-term storage, which has been studied more, is used as a preliminary basis for determining the degree of accelerated aging. When the residual rate of stabilizer content in double-base propellants is greater than 20%, the decomposition rate of double-base propellants after heating is still very low (because the stabilizer can still absorb NO at this time). X , the propellant has not reached the stage of autocatalytic decomposition), at this time, the decomposition gas of the propellant is still rare and will not mutate. However, if the aging degree is too large, so that the residual rate of the stabilizer content in most double-base propellants is less than 5%, most double-base propellants will soon be in the stage of sudden decomposition. In both cases, it is difficult to distinguish the transportation safety of different propellants through inspection results.

[0067] The present invention not only considers the relationship between the content of stabilizer in double-base propellant and transportation safety, but also needs to consider that the energetic plasticizer "sweated out" is stimulated by heat and vibration during transportation, which will also affect transportation safety. When the residual rate of stabilizer is very low, the energetic plasticizer "sweated out" is also very high.

[0068] After comprehensive consideration, it is determined that the degree of accelerated aging is more appropriate for double-base propellants stored at room temperature for 40 years, which can distinguish the transportation safety of most double-base propellants.

[0069] Generally speaking, sample aging follows the principle of "time-temperature equivalence", that is, the effect of aging for a longer time at a lower temperature is the same as the effect of aging for a shorter time at a higher temperature. The higher the accelerated aging temperature, the shorter the time required, but the physical and chemical reaction mode of the sample when the temperature is too high is different from the mode at room temperature, and at this time it no longer follows the principle of "time-temperature equivalence".

[0070] In general, the chemical reaction temperature coefficient r of the propellant 10 =3~4, that is, for every 10°C decrease in temperature, the reaction time is extended by 3~4 times.

[0071] According to the Arrhenius equation, the storage time at room temperature can be calculated from the test time at high temperature. The Arrhenius equation can be changed as follows:

[0072]

[0073] Where: τ0——storage time at room temperature, d;

[0074] τ1——holding time at accelerated aging temperature, d;

[0075] r 10 ——Reaction temperature coefficient for every 10℃ interval;

[0076] T1——accelerated aging temperature, °C;

[0077] T0——normal temperature, 25℃.

[0078] The higher the accelerated aging temperature, the shorter the holding time. However, the physical and chemical reaction mode when the temperature is too high is different from the mode at room temperature. At this time, the Arrhenius equation is no longer applicable. The lower the accelerated aging temperature, the longer the storage time (for example, the accelerated aging temperature is 65°C. According to the above formula, 90 days of holding at 65°C is equivalent to 40 years of storage at room temperature of 25°C). Therefore, the accelerated aging temperature should not be too high or too low.

[0079] Preferably, the heating temperature of the heat aging treatment is 83-87° C., and the aging time is 20-30 days.

[0080] According to the test progress requirements and the variation law of the chemical and physical change pattern of the double-base propellant with temperature, the conditions of the heating aging treatment finally determined in this embodiment are: keeping warm at 85°C for 20 days, which is equivalent to storing the spherical oblate propellant at room temperature of 25°C for 40 years.

[0081] Step 2, obtaining the CO2 content of the gas in the empty sample storage cup;

[0082] Step 3, performing a heating vibration test up to 7 times on the sample storage cup containing the sample obtained in step 1; obtaining the CO2 volume content and N2O volume content of the gas in each sample storage cup after each heating vibration test, and then obtaining the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical flattened charge in each sample storage cup after each heating vibration test;

[0083] Determination of the maximum number of heating vibrations:

[0084] Each heating and vibration represents one day of transportation. Propellants with better safety can be heated and vibrated more times. In other words, the more times they are heated and vibrated, the better they can distinguish, screen, and sort the transportation safety of different propellants. However, the more times they are heated and vibrated, the longer the test cycle.

[0085] Usually, the mileage of highway transportation ranges from 1600km to 2400km, and the longest mileage is 2400km. Assuming that the gravel road is 1000km and the flat road is 1400km, the speed of the dangerous goods transport vehicle on the gravel road is 35km / h and the speed on the flat road is about 80km / h. The transportation time is 8h per day. The calculation shows that the required transportation time is 5.8 days. Considering the need to detect sudden changes in the decomposition gas content, the maximum number of times the sample is heated and vibrated is determined to be 7 times, each time for 8h. After heating and vibrating 7 times, the decomposition gas content of the propellant has not mutated, indicating that the transportation safety of these propellants is relatively high and can meet the requirements of safe transportation. From the application point of view, there is no need to further distinguish and no need to continue heating and vibrating.

[0086] Determination of vibration type during heating vibration:

[0087] During the transportation of products, vibration is an inevitable part. However, conventional cargo vibration testing mainly focuses on the physical damage of the cargo, without considering the chemical impact of vibration converted into thermal stress on the cargo, nor the chemical impact of heat in the environment on the cargo.

[0088] Common vibration types include sinusoidal vibration and random vibration. Sinusoidal vibration is mainly used to find resonance points in the R&D design stage and to optimize cargo to avoid resonance points. Random vibration is used in the laboratory to simulate the vibration during actual transportation. Random vibration is closer to the vibration hazards generated in the actual transportation environment.

[0089] The environment of road transportation is a broadband vibration, which is caused by the combined effect of the support and structure of the vehicle body and the flatness of the road surface. Through the data analysis and processing of automobile transportation vibration obtained by actual measurement of a large number of sports cars, it can be concluded that transportation vibration has the following characteristics:

[0090] a. Automobile transportation vibration is broadband random vibration, and the instantaneous value of vibration basically satisfies the normal distribution.

[0091] b. The energy of automobile transportation vibration is mainly distributed in the frequency range of 0 to 200 Hz, and the energy is more concentrated in the frequency range of 0 to 20 Hz.

[0092] c. The shape of the auto-power spectrum of automobile transportation vibration at different frequencies does not change much. The general trend is that the random frequency increases; the auto-power spectrum density gradually decreases, and peaks appear around 2Hz and 10Hz.

[0093] d. The vibration value (total effective value) of the car's bottom plate varies with different positions, directions, loads, road surfaces and vehicle speeds.

[0094] In summary, the vibration type is determined to be random vibration.

[0095] Temperature determination during heating vibration:

[0096] Nitrocellulose and nitroglycerin in high-plasticizer content propellants have nitrate groups, which can slowly decompose on their own. The gaseous decomposition products have a catalytic effect on the decomposition of nitrate groups. Increasing the temperature can also accelerate the decomposition of nitrate groups. For example, at (70-130) ° C, the decomposition rate of nitrocellulose increases with the increase of temperature. When the temperature rises to above 140 ° C, the decomposition of nitrocellulose becomes very intense. The purpose of this test is to determine the road transportation safety of high-plasticizer content propellants. During the test, the sample heating temperature was low. After heating and vibrating 7 times, the physical and chemical changes of different propellants were not obvious, and it was difficult to distinguish their transportation safety; if the heating temperature is too high, the propellant may have a reaction mode different from the actual situation during transportation. In short, the temperature during heating and vibration should not be too low or too high.

[0097] In this embodiment, the heating temperature of each heating-vibration reaction was finally determined to be 71° C. and the vibration time to be 8 h.

[0098] Step 4, plotting the number of heating vibration tests as the abscissa and the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical propellant as the ordinate, respectively, to obtain a relationship curve between the number of heating vibration tests and the CO2 volume content of each sample in step 3, and a relationship curve between the number of heating vibration tests and the N2O volume content;

[0099] As a preferred solution of this embodiment, a graph is drawn with the number of heating vibration tests (0 to 7 times) as the horizontal axis, and the CO2 volume content (0 to 4.0%) and the N2O volume content (0 to 0.5%) of the decomposition gas of the high plasticizer content spherical propellant as the vertical axis, and the length corresponding to the maximum value of the horizontal axis is made equal to the length corresponding to the maximum value of the vertical axis.

[0100] When double-base propellant is heated, nitrocellulose and nitroglycerin decompose, which will cause a decrease in stabilizer content, a decrease in condensed phase mass, an increase in characteristic decomposition gas content, changes in mechanical properties, a decrease in nitrogen content in nitrocellulose, etc.

[0101] The determination of stabilizer content, mechanical properties and nitrogen content of stabilizer are all destructive tests. If the sample has good stability, 7 times the sample volume of a single test is required. Moreover, the determination of stabilizer content and nitrogen content of nitrocellulose are both chemical methods, and the test steps are cumbersome.

[0102] Condensed phase mass determination and characteristic decomposition gas content determination are both non-destructive detection methods. Even if the sample has good stability, it only needs a single test sample after heating, vibrating, and testing 7 times. Moreover, both detection methods are physical methods and are simple to operate. Relatively speaking, the characteristic decomposition gas content detection can detect both CO2 and N2O gases at the same time, so double checks can be made when judging the results. In addition, the gas chromatography detection limit is much lower than the balance detection limit, so it is preliminarily determined that the parameter to be measured is the characteristic decomposition gas content of the propellant.

[0103] Not only can CO2 and N2O gases be detected due to chemical changes in the aged double-base propellant after being heated and vibrated, but the nitroglycerin "sweat" out of the aged propellant will also decompose into CO2 and N2O gases after being heated and vibrated to a certain extent. The CO2 and N2O gas content decomposed by the characteristic of the propellant is determined as the parameter to be measured.

[0104] When there is enough stabilizer and little nitroglycerin is "sweaten out", there will be very little N2O in the decomposition gas of the propellant; when the remaining amount of stabilizer is small and much nitroglycerin is "sweaten out", obvious N2O will appear in the decomposition gas.

[0105] Step 5: Based on the curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of N2O obtained in step 4, the transportation safety of the high plasticizer content spherical flattened powder is evaluated, specifically including:

[0106] If the acute angle θ between the line segment obtained by connecting two adjacent CO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the CO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the first heating vibration number limit value of the sample;

[0107] If the acute angle θ between the line segment obtained by connecting two adjacent NO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the NO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the second heating vibration number limit value of the sample;

[0108] Compare multiple first heating vibration number limit values ​​and / or second heating vibration number limit values ​​of each sample, and use the heating vibration number value with the smallest value as the safe transportation days of the high plasticizer content flattened spherical drug;

[0109] If the obtained curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of NO2 do not show any sudden changes, it is determined that the safe transportation days of the high plasticizer content spherical flattened bullet are greater than 7.

[0110] In order to be closer to the actual situation of propellant transportation, after each round of heating and vibration testing, the cup cover should not be opened, and the decomposition gas in the sample storage cup should be kept to obtain the impact of the accumulation of decomposition gas on the safety of the sample.

[0111] As a preferred solution of this embodiment, the method is implemented by using a high plasticizer content flattened pill transportation safety test device, the device comprising a sample storage cup 1, a solid sample block 2 and a heating device 3, the sample storage cup 1 comprising a cup cover 11 and a cup body 12: the cup cover 11 has an outer height of 10 mm, a wall thickness of 1 mm and an outer diameter of 24 mm; a one-way air inlet valve 111 and a through air sampling hole 112 are arranged on the upper surface of the cup cover 11, and a sealing pad 13 and an adsorption pad 14 are arranged in the cup cover 11 from top to bottom in sequence;

[0112] The one-way air inlet valve 111 is 6mm away from the center of the cup cover 11, and the gas can enter the sample storage cup 1 through the one-way air inlet valve 111, but the gas in the sample storage cup 1 cannot go out from the one-way air inlet valve 111; the inner side of the cup cover 11 is the first internal thread area; the uppermost end of the cup cover 11 is provided with a sealing gasket 13, the thickness of the sealing gasket 13 is 1.5mm, and the outer diameter is 22mm; below the sealing gasket 13 inside the cup cover 11 is an adsorption pad 14, the thickness of the adsorption pad 14 is 1mm, and the diameter is 22mm; the cup cover 11, the sealing gasket 13, and the adsorption pad 14 are not connected, and the air inlet valve of the cup cover 11 is located directly above the air inlet hole of the sealing gasket 13; the sealing gasket 13 is made of silicone rubber, the adsorption pad 14 is made of cotton fiber, and the cup cover 11 is made of polytetrafluoroethylene;

[0113] The outer surface of the upper end of the cup body 12 is a first external thread area, the height of the first external thread area is 9mm, and the thread of the first external thread area matches the thread of the first internal thread area of ​​the cup cover 11; the wall thickness of the cup body 12 is 1mm, the outer diameter is 22mm, and the outer height is 100mm; the material of the cup body 12 is colorless transparent glass;

[0114] The cup cover 11 is directly above the cup body 12. Tighten the cup cover 11 and the cup body 12, assemble the sample storage cup 1, and the interior of the sample storage cup 1 becomes a closed space. If there is no air inlet valve, the sample storage cup 1 will be repeatedly pumped out, and negative pressure will be formed in the sample storage cup. The volume of the pumped out gas will become less and less, and it cannot be accurately quantified. Therefore, a one-way air inlet valve 111 is designed on the cup cover 11. When the gas in the sample storage cup 1 is pumped out, the gas outside the sample storage cup 1 can enter the sample storage cup 1 through the one-way air inlet valve 111, while the gas generated by the decomposition in the cup body 12 cannot go out through the one-way air inlet valve 111.

[0115] The solid sample block 2 is provided with a plurality of open-topped lofting holes 21 at equal angular intervals along the circumference, a first positioning hole 22 penetrating vertically is provided at the center of the solid sample block 2, and a plurality of second positioning holes 23 penetrating vertically are also provided at equal angular intervals along the circumference on the solid sample block, and the lofting holes 21 and the second positioning holes 23 are alternately arranged along the circumference of the upper surface of the solid sample block;

[0116] There is a handle on the upper surface of the fixed sample block 2. The handle is a half-circle with an outer diameter of 50mm, an inner diameter of 40mm, and a thickness of 5mm. The handle is fixed on the fixed block 2. When not in use, the handle lies flat on the upper surface of the fixed block 2. When the fixed block 2 is moved, the handle is erected. The material of the fixed sample block 2 is thermally conductive plastic.

[0117] The heating device 3 includes a heating mechanism 31 and a heating box 32 arranged above the heating mechanism 31, and the heating box 32 includes a box cover 321 and a box body 322; a heating chamber with an open top is arranged in the box body 322, and a first positioning rod 4 that can be plugged into and matched with the first positioning hole 22 and a second positioning rod 5 that can be plugged into and matched with the second positioning hole 23 are arranged in the heating chamber.

[0118] The box body 322 is a cylinder with a height of 120 mm, an inner diameter of 170 mm, and an outer diameter consistent with the outer diameter of the box cover 321; the wall of the box body 322 consists of three layers; the wall includes a 1 mm thick inner layer of a cylinder wall metal plate, a 20 mm thick asbestos middle layer, and a 2 mm thick metal outer layer, which are fitted from the inside to the outside; the bottom of the box body 322 is a 2 mm thick metal plate; the 6 second positioning rods are equidistantly distributed.

[0119] The heating device 3 is cylindrical as a whole, and the box cover 321 is a flat cylinder. The box cover 321 consists of a box cover body and a box cover metal shell; the box cover body consists of an upper and lower layer, the lower layer of the box cover body is a buffer fastening layer, which is composed of silicone rubber and has a thickness of 10mm; the upper layer of the box cover body is an asbestos insulation layer, which is 20mm thick; the side and top surface of the box cover body are wrapped with a metal shell, and the thickness of the metal shell is 2mm; the heating device adopts electric heating.

[0120] As a preferred solution of this embodiment, the one-way air inlet valve 111, the air collection hole 112 and the cup cover 11 are arranged with their centers collinear.

[0121] As a preferred solution of this embodiment, the solid sample block 2 is cylindrical, the number of the lofting holes 21 is 6, the distance between the center of the lofting hole 21 and the center of the first positioning hole 22 is 40 mm, and the lofting hole 21 includes a first inner cavity 211 and a second inner cavity 212 connected from top to bottom, the first inner cavity 211 has a diameter of 25 mm and a depth of 100 mm, and the second inner cavity 212 has a diameter of 20 mm and a depth of 10 mm.

[0122] This method uses a gas chromatograph 5 to detect the gas in the sample storage cup 1.

[0123] When manually using an injection needle to collect gas and inject it into the chromatograph, problems such as gas leakage and poor injection repeatability often occur. This relies too much on the operator's level and the human influence factor is relatively large. In order to reduce such factors that affect the test results, the present invention adopts technical means such as a gas collection device, a vacuum pump, and a quantitative tube. The operator only needs to insert the sampling needle of the gas collection device into the sample storage cup, and the gas chromatograph can automatically extract the decomposition gas for detection, thereby minimizing the errors caused by human operation.

[0124] Generally, when using a gas chromatograph to detect gas, the same gas is required to be injected 2 to 3 times. When the chromatographic peak changes by ≤5%, the entire gas detection system (including gas sampling) is considered to be stable. However, the decomposition gas content generated in the sample storage cup in this test is relatively small. When gas is continuously extracted from the sample storage cup, the reduced gas in the sample storage cup will be replenished into the sample storage cup by the atmosphere through the air inlet valve 111, and there will be a trend of gradually decreasing characteristic gas content. Therefore, the method of continuously extracting gas from the sample storage cup can no longer be used to judge the stability of the system.

[0125] In summary, in this embodiment, when judging the state of the gas detection system, the method of "pumping the indoor gas from the gas sampling device into the quantitative tube, then injecting it into the chromatographic column for separation, detecting it with a thermal conductivity detector, and finally recording the chromatographic peak areas of oxygen and nitrogen; performing gas sampling and detection multiple times in succession; assuming that the chromatographic peak areas of oxygen and nitrogen detected by two consecutive samplings are marked as S1 and S2 respectively, and setting θ=|S1-S2|×2÷(S1+S2), when θ≤5%, judging that the instrument state is stable" is adopted.

[0126] The heating vibration test process of this test device is as follows:

[0127] The spherical flattened powder with high plasticizer content is loaded into the sample storage cup 1, and placed in the sample placement hole 21 of the solid sample block 2, and then the solid sample block 2 is placed in an oven to perform a heat aging treatment on the spherical flattened powder with high plasticizer content; then the solid sample block 2 is placed in a heating device 3 placed on a vibrator 4, and a heating vibration test is completed according to the set parameters. After the test, the sample storage cup is taken out and cooled to room temperature, and then the gas in the sample storage cup 1 is detected by a gas chromatograph, and the detection data is recorded.

[0128] Application Example 1

[0129] In this application example, it is necessary to determine the optimal production process parameters of a high plasticizer content spherical oblate propellant. Three high plasticizer content spherical oblate propellants are produced according to different process parameters. The three propellants have the same formula composition, and their energetic plasticizers are all nitroglycerin, the nitroglycerin content is 30%, and the particle size is between 0.8mm and 1.1mm. This application example adopts the invention method disclosed in Example 1, which specifically includes:

[0130] (1) Three high plasticizer content spherical flattened medicine samples 1#, 2#, and 3# with the same formulation but different process parameters, each sample weighed 2 specimens; a total of 6 specimens were weighed for the three samples, marked as 1#-1, 1#-2, 2#-1, 2#-2, 3#-1, and 3#-2, and the weight of each specimen was 9.9 g to 10.1 g;

[0131] (2) six sample storage cups 1 containing samples are placed into the six sample placement holes 21 of the fixed block 2, and are placed together in an oven. After continuous heating and aging at 85°C for 20 days, the cups are taken out and cooled to room temperature.

[0132] (3) Place the fixed block 2 with the six sample storage cups 1 placed in (2) and cooled to room temperature into the heating box 32, and position the fixed block 2 by means of the first positioning rod 4 and the first positioning hole 22, and the second positioning rod 5 and the second positioning hole 23; and place the handle flat on the upper surface of the fixed block 2;

[0133] (4) Cover the box cover 321 on the box body 322, and fix the heating mechanism 31 on the vibrator by a clamp; heat the heating mechanism to 71°C, set the vibrator to a random vibration mode, start timing after the temperature stabilizes, and start the heating vibration test; stop the heating vibration after 8 hours, take out the fixing block 2 containing 6 sample storage cups 1, cool to room temperature, and wait for testing;

[0134] (6) Turn on the gas chromatograph, set the temperature of the thermal conductivity detector to 250°C and the temperature of the chromatographic column to 80°C; after the gas chromatograph is stable, continuously extract the indoor gas for detection; set the chromatographic peak areas of oxygen and nitrogen detected for two consecutive times to be S i and S i+1 , let θ=|S i -S i+1 |×2÷(S i +S i+1 ), when θ≤5%, start detection; first extract the gas in the empty sample storage cup 1, and obtain the CO2 content V0(CO2) of the gas in the empty sample storage cup;

[0135] Then, the sampling needles are inserted into the six sample storage cups 1 containing the samples in turn, and the CO2 content V(CO2) and the N2O content V(N2O) in the sample storage cups 1 are extracted and tested;

[0136] The CO2 content C(CO2)=V(CO2)-V0(CO2) and the N2O content C(N2O)=V(N2O) in the decomposed gas after this heating and vibration are obtained;

[0137] Conduct the 2nd to 7th rounds of heating vibration tests and tests; and then obtain the CO2 volume content C(CO2) and N2O volume content C(N2O) of the decomposition gas of the high plasticizer content spherical protrusion in each sample cup after each heating vibration test;

[0138] (7) With the number of heating vibration tests as the abscissa and the CO2 volume content C(CO2) and N2O volume content C(N2O) of the decomposition gas of the high plasticizer content spherical propellant as the ordinate, the relationship curve between the number of heating vibration tests and the CO2 volume content, i.e., the C(CO2)-n curve, and the relationship curve between the number of heating vibration tests and the N2O volume content, i.e., the C(N2O)-n curve, are obtained for each sample;

[0139] (8) Based on the obtained C(CO2)-n curve and C(N2O)-n curve, the transportation safety of high plasticizer content flattened pellets was evaluated.

[0140] like Figure 5 and Figure 7 As shown, the C(CO2)-n curves of the two parallel samples of sample 1# and the two parallel samples of sample 2#, as well as the C(N2O)-n curves, did not show any sudden jumps, so it was determined that the number of safe transportation days for samples 1# and 2# was greater than 7.

[0141] like Figures 5 to 8 As shown in Figure 6, the C(N2O)-n curves of the two parallel samples of sample 3# did not experience a sudden jump, but in the C(CO2)-n relationship curve of sample #-1 in Figure 63, the acute angle θ between the line segment connecting the 5th and 6th CO2 volume content values ​​and the horizontal line is ≥60°, indicating that the relationship curve has a sudden jump when n=6. Therefore, it can be determined that the safe transportation days of sample 3# = 6, and there is no need to conduct the next round of heating vibration test for the two parallel samples 3#-1 and 3#-2.

[0142] From the test results, it can be estimated that the transportation safety of 1# and 2# samples after the expiration of long-term storage is very good, and it is estimated that the transportation safety of 3# sample after the expiration of long-term storage is worse than that of 1# and 2# propellants.

[0143] According to the estimated results of the present invention, it can be determined that for a certain high plasticizer content spherical oblate propellant with the same composition, the production process parameters of samples 1# and 2# are better than those of sample 3#. Application Example 2

[0144] In this application example, it is necessary to test two high plasticizer content propellant samples A and B, both of which contain nitroglycerin as energetic plasticizers, and the nitroglycerin content is 33%. The particle sizes of the two samples are different, the particle size of sample A is between 0.4mm and 0.7mm, and the particle size of sample B is between 0.8mm and 1.1mm. The method disclosed in the embodiment is used to evaluate the transportation safety of the two propellants after the storage expires.

[0145] Sample A and sample B were prepared with two parallel samples A-1, A-2, B-1, B-2, and the four curves finally obtained were shown in Figures 9 to 12 .

[0146] from Fig. 9 and Fig.10 It can be seen from the curve that the relationship curve between the number of heating vibration tests and the volume content of CO2 of the parallel sample A-1 of sample A has a sudden jump when n=5, and it is determined that the number of safe transportation days of sample A is 5. The two parallel samples of sample A are no longer subjected to the 6th and 7th rounds of heating vibration.

[0147] from Fig.11 and Fig.12 It can be seen from the curve that the relationship curve between the number of heating vibration tests and the volume content of N2O of the parallel sample B-2 of sample B has a sudden jump when n=6, and it is determined that the number of safe transportation days of sample B is 6, and the two parallel samples of sample B are no longer subjected to the seventh round of heating vibration;

[0148] It can be determined that the transportation safety of sample B after the expiration of long-term storage is better than that of sample A.

[0149] From this embodiment, it is estimated that for a certain spherical oblate propellant with high plasticizer content of the same component ratio and process, after the long storage expires, the propellant with a particle size of 0.8-1.1 mm is safer to transport than the propellant with a particle size of 0.4-0.7 mm.

[0150] The reason for this is that the smaller the particle size, the larger the surface area, the more nitroglycerin it "sweats out", and the higher the degree of autocatalysis.

[0151] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0152] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration, characterized in that: The following steps are involved: Step 1, placing a plurality of sample storage cups filled with high-plasticizer content spherical flat medicine samples into a solid sample block, and then placing the solid sample block into an oven for heating aging treatment and then naturally cooling to room temperature; Step 2, obtaining the CO2 content of the gas in the empty sample storage cup; Step 3, performing a heating vibration test up to 7 times on the sample storage cup containing the sample obtained in step 1; obtaining the CO2 volume content and N2O volume content of the gas in each sample storage cup after each heating vibration test, and then obtaining the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical flattened charge in each sample storage cup after each heating vibration test; Step 4, plotting the number of heating vibration tests as the horizontal axis and the CO2 volume content and N2O volume content of the decomposition gas of the high plasticizer content spherical flattened charge as the vertical axis, respectively, to obtain a relationship curve between the number of heating vibration tests and the CO2 volume content of each sample, and a relationship curve between the number of heating vibration tests and the N2O volume content; Step 5: Based on the curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of N2O obtained in step 4, the transportation safety of the high plasticizer content spherical flattened powder is evaluated, specifically including: If the acute angle θ between the line segment obtained by connecting two adjacent CO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the CO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the first heating vibration number limit value of the sample; If the acute angle θ between the line segment obtained by connecting two adjacent NO2 volume content values ​​and the horizontal line in the relationship curve between the heating vibration test number and the NO2 volume content is ≥ 60°, it is considered that a sudden jump has occurred in the relationship curve, and the heating vibration number corresponding to the right end point of the line segment is recorded as the second heating vibration number limit value of the sample; Compare multiple first heating vibration number limit values ​​and / or second heating vibration number limit values ​​of each sample, and use the heating vibration number value with the smallest value as the safe transportation days of the high plasticizer content flattened spherical drug; If the obtained curves of the relationship between the number of heating vibration tests and the volume content of CO2 and the curves of the relationship between the number of heating vibration tests and the volume content of NO2 do not show any sudden changes, it is determined that the safe transportation days of the high plasticizer content spherical flattened bullet are greater than 7.

2. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: The heating temperature of the heat aging treatment is 83-87° C., and the aging time is 20-30 days.

3. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: The heating temperature of the heating vibration test is 70-72° C., the vibration time is 7-9 hours, the vibration frequency is 9 Hz-11 Hz, and the amplitude is 15 mm-25 mm.

4. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: The volume content of CO2 in the decomposition gas of the high plasticizer content spherical flattening charge in step 3 = the volume content of CO2 in the sample storage cup measured after the heating and vibration test - the volume content of CO2 in the gas in the empty sample storage cup; the volume content of N2O in the decomposition gas of the high plasticizer content spherical flattening charge = the volume content of N2O in the sample storage cup measured after the heating and vibration test.

5. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: The filling mass of the high plasticizer content spherical flat medicine in the sample cup is 9.9g-10.1g.

6. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: In the step 4, the number of heating vibration tests is 0 to 7 times as the horizontal axis, and the CO2 volume content of 0 to 4.0% and the N2O volume content of 0 to 0.5% of the decomposition gas of the high plasticizer content spherical flattened charge are used as the vertical axis to draw a graph, and the length corresponding to the maximum value of the horizontal axis is equal to the length corresponding to the maximum value of the vertical axis.

7. A method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: Two parallel samples are made for each propellant sample for heating vibration test. After a sudden jump occurs in the relationship curve between the heating vibration test number and the CO2 volume content or the relationship curve between the heating vibration test number and the N2O volume content of any parallel sample, the two parallel samples will no longer be subjected to subsequent heating vibration tests.

8. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 1, characterized in that: The method is implemented by using a high-plasticizer-content flattened pill transportation safety test device, the device comprising a sample storage cup (1), a solid sample block (2) and a heating device (3); the sample storage cup (1) comprises a cup cover (11) and a cup body (12); a one-way air inlet valve (111) and a through air sampling hole (112) are arranged on the upper surface of the cup cover (11); a sealing pad (13) and an adsorption pad (14) are arranged in order from top to bottom in the cup cover (11); The sample fixing block (2) is provided with a plurality of top-opened lofting holes (21) at equal angular intervals along the circumference; a first positioning hole (22) penetrating vertically is provided at the center of the sample fixing block (2), and a plurality of second positioning holes (23) penetrating vertically are also provided at equal angular intervals along the circumference on the sample fixing block; the lofting holes (21) and the second positioning holes (23) are alternately arranged along the circumference of the upper surface of the sample fixing block; The heating device (3) comprises a heating mechanism (31) and a heating box (32) arranged above the heating mechanism (31); the heating box (32) comprises a box cover (321) and a box body (322); a heating chamber with an open top is arranged in the box body (322); a first positioning rod (4) which can be plugged into and matched with a first positioning hole (22) and a second positioning rod (5) which can be plugged into and matched with a second positioning hole (23) are arranged in the heating chamber.

9. The method for estimating the transportation safety of high-plasticizer-content flattened pellets under heat and vibration as claimed in claim 8, characterized in that: The one-way air inlet valve (111), the air collection hole (112) and the center of the cup cover are arranged on the same line.

10. The method for estimating the transportation safety of flattened pellets with high plasticizer content under heat and vibration as claimed in claim 8, characterized in that: The sample fixing block (2) is cylindrical, the number of the sample lofting holes (21) is 6, and the distance between the center of the sample lofting hole (21) and the center of the first positioning hole (22) is 40 mm; the sample lofting hole (21) comprises a first inner cavity (211) and a second inner cavity (212) which are connected from top to bottom, and the diameter of the first inner cavity (211) is greater than the diameter of the second inner cavity (212).

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