RU2523811C1 - Method for cleaning fuel tanks of rocket pods from contaminating particles during their preparation for bench tests - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: cleaning of fuel tanks is carried out in "filling-draining" cycles by filling a tank with a liquid (fuel) and further draining. In this case, content of contaminating particles in the liquid, passing through the pipeline during the tank filling, and in the liquid passing through the pipeline during draining from the tank is determined. An amount of contaminating particles removed from the tank is determined by the difference of the measured contents of the contaminating particles in the liquid during the tank draining and filling. Filters for cleaning the working liquid are installed at an inlet section of a pipeline for supplying the liquid into the tank and at an outlet section of the drain pipeline. Calculation expressions to determine content of the contaminating particles in the liquid passing through the pipelines, as well as to determine a volume of the liquid required to remove the given weight of the contaminating particles from the tank, are given.

EFFECT: application of the invention permits to determine the amount of contaminating particles removed from the tank and left in the tank at the selected cleaning modes, reduce rates of the working liquid consumption, determine the liquid volume, required to achieve the specified cleanness, and reduce the complexity of the cleaning process.

3 cl, 2 dwg

Description

The invention relates to the field of engineering and can be used, in particular, in the aviation, rocket and other fields of technology in which tanks are used for working fluids, which are required during their operation to limit the content of contaminants in them.

So, in particular, when conducting bench testing of rocket and space technology (RKT) products, namely rocket stages, including fuel tanks, high demands are placed on limiting the content of contaminants in them, for which, in conditions of test complexes, preparation for testing requires work to remove contaminants from fuel tanks of missile blocks to a given content.

Since the rocket stages are fixedly mounted on the test bench in a vertical position in a rigid corset, it is not possible to use methods of cleaning fuel tanks that contribute to the efficient separation of contaminants. Therefore, as a rule, for this, a method of cleaning fuel tanks is used, based on their repeated washing with a working fluid.

A known method of cleaning the supply system of the working fluid from mechanical impurities to a predetermined content, including filling the tank with a working fluid and draining it and determining after draining the working fluid from the tank the mass of particles of contaminants removed from the tank (see P.N.Belyanin, V.M. Danilov, Industrial Purity of Machines, Moscow: Mashinostroenie, 1982, p. 123, 124). The known method is adopted as a prototype, since it can be used to clean the fuel tanks of missile blocks from particles of contaminants in preparing them for bench tests.

The essence of the known cleaning method is as follows. From the refueling bench capacity, the fuel tank of the stage is filled with a working fluid (fuel) of a certain purity class. Then the fuel is drained from the tank into the receiving drain tank through the control filter, after which the filter is removed and the particles of impurities detained on the filter element are examined. Based on the results of the analysis of the particles of contaminants deposited on the filter element of the control filter, the purity of the tank is judged. If the fixed pollution content exceeds its permissible value, the cleaning method is repeated.

The known method has disadvantages, which are as follows.

The process of removing particles of contaminants from the tank when draining fuel from it is subject to a certain law that determines the relationship between the amount (volume) of spilled fuel and the number of contaminants taken away (removed) from the system, i.e. the more the number of fillings-drains of fuel performed, the less pollution remains in the tank. In the known method, when preparing the tank, the content of contaminants in it is not known in advance. Due to the fact that the tanks of the products to be tested have a different internal design and volume and, therefore, different pollution (different unknown pollution content), after one cycle of filling and draining fuel from it, the pollution content in the tank, although it decreases, no less remains unknown. To clean the tank to a predetermined contamination content, the amount of fuel to be spilled is selected taking into account its volume with previously conducted spills. However, it is impossible to predict the required number of cleaning cycles (filling - draining) and, accordingly, the required amount of working fluid (fuel), because the amount of contamination remaining in the tank is unknown. In addition, the amount of contaminants introduced into the tank with the working fluid during filling is not known, which also affects the results of cleaning the tank.

For reliable tank cleaning, the number of fill-drain cycles is increased.

In this case, the fuel is drained from the tank into the receiving stand tank, and the tank is filled with a new portion of fuel from the pre-refueling tank stand. This leads to an increase in the complexity of cleaning the fuel tank and additional material costs associated with an increase in the consumption of expensive working fluid - rocket fuel.

The technical problem solved by the invention is to reduce the flow rate of the working fluid (rocket fuel) necessary to clean the tank of the rocket block from particles of contaminants to a given contamination content, the complexity of cleaning and the ability to determine the amount of contamination remaining in the tank.

This is achieved by the fact that in the known method of cleaning fuel tanks of rocket blocks from particles of contaminants when preparing them for bench tests, including filling the tank with working fluid from a refueling bench tank, draining the working fluid from the tank into a drain bench tank, at the end of which the mass of particles of contaminants is determined removed from the tank, according to the invention, after filling the tank with a working fluid, determine the mass of particles of contaminants entering the tank with the working fluid, then the difference in the mass of particles of contaminants The masses of contaminants that were removed from the tank during discharge and entered the tank during filling determine the mass of contaminants that were in the tank before it was filled with working fluid and then removed during draining, after which a second cycle of filling the tank with working fluid and draining it from the tank to determine the particle mass contaminants entering the tank when filling with a working fluid and being in the tank before the second filling with working fluid and removed during the second discharge, then taking into account the mass of particles of contaminants that were in the tank before each filling working fluid and removed at each discharge, determine the mass of contaminant particles that can be removed during subsequent filling-drain cycles, and clean the tank until the specified contaminant content in the tank is reached, while a filling stand is used to drain the working fluid to drain the working fluid capacity, and when filling and draining from the tank, the working fluid is passed through process filters.

In addition, the filling of the tank with a working fluid is carried out through a filling pipe with flow measurement and continuous sampling of a part of the liquid from the filling pipe to the selection line through a control filter with a flow measurement and returning the filtered liquid to the filling pipe, and the mass of particles of contaminants entering the tank with the working liquid , determined by the formula, including the volume of liquid, determined by the measured values of the flow rate,

, $$M_{H\mathrm{one}}=m_{2H\mathrm{one}}{k}_{tH}\left(\frac{V_{0H\mathrm{one}}}{V_{2H\mathrm{one}}}-\mathrm{one}\right)$$

,

where M _H1 is the mass of particles of contaminants in the liquid passed into the tank through the filling pipeline during the first filling, m _2H1 is the mass of particles of contaminants in the liquid passed through the pipe for selection of the filling pipe deposited on the control filter of the pipe selection pipe for the first filling, V _0H1 - the volume of liquid passed through the filling pipeline into the tank during the first filling, V _2H1 - the volume of liquid passed through the sampling line from the filling pipeline, a control filter of the sampling line and returned to the pipeline filling behind the throttle device during the first filling of the tank, k _tH - correction factor;

the working fluid is drained from the tank through a drain pipe with flow measurement and the continuous selection of part of the liquid from the drain pipe to another sampling line through a control filter with a measurement of its flow rate and the return of the filtered liquid to the drain pipe, and the mass of particles of contaminants removed from the tank is determined with taking into account the volume of liquid determined by the measured values of the flow rate, according to the formula

, $$M_{C\mathrm{one}}=m_{2C\mathrm{one}}{k}_{tC}\left(\frac{V_{0C\mathrm{one}}}{V_{2C\mathrm{one}}}-\mathrm{one}\right)$$

,

where M _C1 is the mass of particles of contaminants in the liquid passing through the drain pipe from the tank at the first discharge, m _2C1 is the mass of particles of contaminants in the liquid passing through the drain pipe selection line, deposited on the control filter of the drain pipe selection line at the first drain, V _0C1 - the volume of fluid passing through conduit drain from the tank during the first drain, V _2C1 - the volume of fluid passing along the selection line of the drain line, the control line selection filter and returned to the discharge conduit for the throttle device, k _tC - mandrel coefficient;

moreover, the mass of particles of contaminants ΔM ₁ , which were in the tank before filling it with a working fluid and removed when draining from the tank, is determined by the formula

; $$\Delta M_{\mathrm{one}}=M_{C\mathrm{one}}+m_{2C\mathrm{one}}-M_{H\mathrm{one}}$$

;

after the second cycle of filling the tank with a working fluid and draining it from the tank, determine the mass of particles of contaminants entering the tank with the working fluid during the second filling, and the mass of particles of contaminants removed from the tank during the second discharge, taking into account the volumes of liquid determined from the measured flow rates, respectively according to the formulas

, $$M_{C2}=m_{2C2}{k}_{tC}\left(\frac{V_{0C2}}{V_{2C2}}-1\right)$$

, $$M_{H2}=m_{2H2}{k}_{tH}\left(\frac{V_{0H2}}{V_{2H2}}-\mathrm{one}\right)$$

, $$M_{C2}=m_{2C2}{k}_{tC}\left(\frac{V_{0C2}}{V_{2C2}}-\mathrm{one}\right)$$

,

where M _H2 is the mass of particles of contaminants in the fluid passing through the filling pipe during the second filling of the tank, m _2H2 is the mass of particles of contaminants in the liquid passing through the pipe of the filling pipe deposited on the control filter of the selection pipe of the filling pipe during the second filling of the tank, V _0H2 - the volume of liquid that passed through the filling pipeline into the tank during the second filling, V _2H2 - the volume of liquid that passed through the sampling line from the filling pipeline, a control filter of the sampling line and returned to the pipe filling filler behind the throttle device during the second filling of the tank, k _tH is the correction factor, M _C2 is the mass of particles of contaminants in the liquid passing through the drain pipe at the second drain, m _2C2 is the mass of particles of pollution particles in the liquid passing through the drain pipe selection line, deposited on the control filter of the drain pipe selection line during the second discharge of liquid from the tank, V _0C2 is the volume of liquid passed through the drain pipe from the tank during the second liquid discharge from the tank, V _2C2 is the volume of liquid passed through the selection line and from the discharge pipeline and returned to the discharge pipe after the throttle device during the second discharge of liquid from the tank, k _tC - correction factor,

determine the mass of particles of contaminants ΔM ₂ that were in the tank until the second filling it with a working fluid and removed during the second discharge from the tank, according to the formula

, $$\Delta M_2=M_{C2}+m_{2C2}-M_{H2}$$

,

using the obtained values ΔM ₁ , ΔM ₂ are the equations that determine the dependence of the mass of particles of contaminants removed from the tank on the volume of liquid used,

for the first cleaning cycle:

, $$\frac{\Delta M_{\mathrm{one}}}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0{V}_{0H\mathrm{one}}}}$$

,

for the second cleaning cycle:

, $$\frac{\Delta M_{\mathrm{one}}+\Delta M_2}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0\left(V_{0H\mathrm{one}}+V_{0H2}\right)}}$$

,

as a result of the solution of which the constants ΔM ₀ , A ₀ (ΔM ₀ is the initial content of contaminants in the system) are determined constant (at selected cleaning modes), after which the mass of contaminant particles ΔM, which can be removed during subsequent cleaning cycles using the volume of working fluid, is determined V _0H , by the equation

$$\frac{\Delta M_{\mathrm{one}}+\Delta M_2+\Delta M}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0\left(V_{0H\mathrm{one}}+V_{0H2}+V_{0H}\right)}}$$

and conduct tank cleaning to an acceptable value for the content of contaminants.

In this case, the flow regimes of the working fluid are preliminarily sequentially adjusted in the sections of the filling and draining pipelines and in the corresponding fluid sampling lines to establish conditions for equal fluid velocities in the sampling elements of the sampling devices and in the sections of the filling and draining pipelines at the installation sites for the liquid sampling devices by pouring them with a working fluid, measuring the flow rates of them, determining the mass of particles of contaminants deposited on control filters by tkov pipeline filling and discharge lines and the selection of the liquid, with which, taking into account the volume of liquid defined by the measured values of the costs determined correction coefficients k _tH, k _tC by formulas

, $$k_{tC}=\frac{m_{1tC}}{m_{2tC}\left(\frac{V_{0tC}}{V_{2tC}}-1\right)}$$

, $$k_{tH}=\frac{m_{\mathrm{one}tH}}{m_{2tH}\left(\frac{V_{0tH}}{V_{2tH}}-\mathrm{one}\right)}$$

, $$k_{tC}=\frac{m_{\mathrm{one}tC}}{m_{2tC}\left(\frac{V_{0tC}}{V_{2tC}}-\mathrm{one}\right)}$$

,

where m _1tH is the mass of particles of contaminants in the liquid passing through the section of the filling pipeline during adjustment, deposited on the control filter of the drain line, m _2tH is the mass of particles of contaminants in the liquid passing through the line of sampling, deposited on the control filter of the line of selection of the section of the filling pipeline during tuning , V _0tH - the volume of fluid passing along the pipeline filling portion when setting, V _2tH - the volume of fluid passing through the pipeline selecting section when setting the filling conduit, m _1tC - mass of particles contaminated minutes in fluid passing over the site of the pipeline discharging when configuring deposited on a control filter drain line, m _2tC - weight contaminant particles in a fluid passed through line selection deposited on the test filter line selection drain conduit portion when setting, V _0tC - volume of liquid , which passed through the drain pipeline section during adjustment, V _2tC is the volume of fluid passing through the drain pipe section during adjustment.

In Fig. 1, a pneumohydraulic diagram is shown in accordance with which a method of cleaning a tank of a rocket block (stage) from mechanical impurities when preparing it for bench tests is implemented, and Fig. 2 shows a pneumohydraulic diagram of a pouring stand, on which the flow regimes of the working fluid are set in sections of the filling and discharge pipelines to determine correction factors.

The diagram depicted in Fig. 1 includes a refueling bench container 1 with a working fluid - fuel, pipelines for filling 2 with fuel of the tank 4 of the test stage and draining 3 fuel from the tank 4 into the refueling bench container 1, shut-off valves 5, 6, 7. Refueling bench capacity 1 is equipped with pressurization and refueling systems and at the same time it is a drain bench capacity.

The filling pipe 2 of the tank 4 with fuel is connected to the output of the shut-off valve 5, installed at the outlet of the refueling bench container 1, and contains a process filter 8, a flowmeter 9 and a shut-off valve 6. The filling pipe 2 contains a section consisting of sequentially installed - part flow selection devices fuel 10 and throttle device 14. In this case, the device for taking part of the fuel flow 10 is connected to the selection line 11, in which the valve 16, the control filter 12, the flow meter 13 and the valve are installed l 15. The output of the selection line 11 is connected to the output of the section of the filling pipe 2 behind the throttle device 14 to the shut-off valve 6 connected to the tank 4 filling system.

The pipeline for draining fuel 3 from the tank 4 contains a shut-off valve 7 connected to a portion of the filling-draining pipeline of the tank 4, to which a removable section is connected, consisting of sequentially installed devices for selecting a part of the fuel flow 17 and a throttle device 23. In this case, the device for taking part of the flow fuel 17 is connected to a sampling line 21, in which a valve 25, a control filter 20, a flowmeter 22 and a valve 24 are installed in series. The output of the sampling line 21 is connected behind the throttle device 23 to the output of the section and the discharge pipe 3, connected through a process filter 18 and a flow meter 19 with the output of the shut-off valve 5.

Due to the fact that in the manufacture and installation of a device for taking part of the fuel flow, deviations from the design dimensions, violation of the accuracy of the location (placement) of the intake elements of the selection devices during installation in the pipeline are possible, during operation of the devices these features will lead to a deviation of fuel costs and speeds from the calculated and , as a consequence, to a violation of the laws governing the distribution of contaminant particles in the fuel flow in the filling and discharge pipelines and in the corresponding highways for the selection of a part of the fuel flow, i.e. to reduce the accuracy of determining the content of contaminant particles in the fuel flowing in the pipeline.

To determine the correction factors associated with the establishment of real fuel flow regimes in the intake elements of the sampling devices and in the filling and discharge pipelines, in the places of their installation, the fuel flow regimes are preliminarily adjusted in the removable sections of the filling and discharge pipelines separately for each pipeline.

Pneumohydrochemical pouring stand (figure 2), which is used to configure the flow regimes of the working fluid in the sections of the filling and discharge pipelines to determine correction factors, includes a refueling bench tank 26 with a boost-drainage system and a refueling-drain system. The drain line from the refueling bench container 26 comprises a shut-off valve 27, a flow meter 28, a drain line 30 on which a control filter 31 is installed, a shut-off valve 32 connected to the drain bench capacity 33.

First, between the outlet of the flow meter 28 and the drain line 30, a section 29 is installed from the filling line (see FIG. 1), including a sequentially installed device for selecting a part of the fuel flow 10 and a throttle device 14. In this case, the device for taking part of the fuel flow 10 is connected to the selection line 11, in which the valve 16, the control filter 12, the flow meter 13 and the valve 15 are installed in series. The output of the selection line 11 is connected to the output of section 29 behind the throttle device 14. The positions corresponding to other elements of the removable section of the discharge pipe of Fig. 1.

The adjustment of the flow regimes in the removable area is as follows (see figure 2).

1. In the initial state, the throttle device 14 is adjusted to a predetermined mode of fluid flow in the intake element of the selection device 10 and in the pipeline at the location of the selection device.

2. A neutral gas with a predetermined pressure is supplied to the refueling bench container 26, the shut-off valves 27 and 32 and the valves 16 and 15 are opened on the sampling line, and the liquid enters through the flow meter 28 into the pipeline section 29. Part of the liquid through the sampling device 10 continuously enters the selection line 11 and along the selection line to the control filter 12, where contaminant particles are deposited on the filter element. The liquid filtered by the control filter 12 enters the flow meter 13 of the sampling line and then returns to the pipe 29 after the throttling device 14.

3. The main fluid flow passes through the filling pipeline section and then, connecting to the fluid flow exiting the selection line 11, through the drain line 30 through the control filter 31, the shut-off valve 32 enters the drain stand tank 33. The spill time is determined based on experimental data .

4. At a given point in time, shut-off valves 27, 32 are closed and the fluid supply to the portion of the filling pipeline is stopped. Then, valves 16 and 15 on the selection line are closed, control filters 12 and 31 are removed, they are disassembled, precipitated contaminants are removed, their analysis is carried out, including mass determination.

According to the measured fluid flow rates 28 and 13, the flow rates and taking into account the fluid flow time determine the fluid volumes that have passed through the filling pipe and through the sampling line.

5. To determine the correction factors in the drain pipeline, the flow regimes of the working fluid in it and in a removable section of the drain pipeline (see Fig. 1), pre-installed on the pouring stand (see Fig. 2) between the outlet of the flow meter 28 are similarly configured drain line 30. Section 29 of the drain pipeline includes a sequentially installed device for selecting part of the fuel flow 17 and a throttle device 23. In this case, the device for selecting part of the fuel flow 17 is connected to the selection line 21, in which valve 25, a control filter 20, a flow meter 22, and a valve 24 are installed. The outlet of the sampling line 21 is connected to the outlet of the drain pipe section behind the throttle device 23. In this case, the masses of impurities detained on the control filters 20 and 31 are determined, and 28 22 values of fluid flow rates and taking into account the time of fluid flow determine the volume of fluid passed through the filling pipe and on the selection line.

6. Using the data obtained, the values of the correction factors k _tH , k _tC are determined by the formulas

$$k_{tH}=\frac{m_{\mathrm{one}tH}}{m_{2tH}\left(\frac{V_{0tH}}{V_{2tH}}-\mathrm{one}\right)},\left(\mathrm{one}\right)$$

$$k_{tC}=\frac{m_{\mathrm{one}tC}}{m_{2tC}\left(\frac{V_{0tC}}{V_{2tC}}-\mathrm{one}\right)},\left(2\right)$$

where m _1tH is the mass of contaminants in the fluid passing through the filling pipeline section during adjustment, deposited on the control filter of the drain line, m _2tH is the mass of contaminants in the liquid passing through the sampling pipeline deposited on the control filter in the selection line filter, filling the pipeline section during the adjustment, V _0tH - the volume of fluid passing along the pipeline filling portion when setting, V _2tH - the volume of fluid passing along the pipeline section selection line when configuring the filling, m _1tC - mass particle contamination in the fluid, roshedshey the section of conduit drain when configuring deposited on a control filter drain line, m _2tC - mass particle contamination in the fluid held by the selection line deposited at the control filter pipeline section selection line drain when setting, V _0tC - the volume of fluid passing over the site the discharge pipeline during adjustment, V _2tC is the volume of fluid passing through the selection line for the section of the drain pipeline during adjustment.

After adjusting and determining the correction factors, removable sections of the filling and discharge pipelines with the fixed positions of the liquid withdrawal devices 10 and 17 and the throttle devices and 23 are installed on a stand for cleaning the fuel tank 4 of the rocket block from contaminants in preparation for bench tests (see figure 1).

The method of cleaning the fuel tanks of rocket blocks from particles of contaminants when preparing them for bench tests is as follows, Fig.1.

1. Spend the first cycle of cleaning the tank 4 by filling it with fuel and subsequent drain. In this case, the fuel consumption values when filling the tank 4 and when draining are selected from the condition of equal or exceeding fuel consumption during the test stage (specified in the documentation for testing) and maintained the same for all cycles.

2. Filling the tank 4 with fuel is carried out from the refueling bench container 1 through the filling line 2. The system of pressurization of the tank 1 with neutral gas is turned on (the system is configured to maintain a given fuel consumption through the pipe 2) and open valves 5, 6, valves 15, 16 on the selection line samples 11 and a valve at the inlet to the tank 4. Fuel from the tank 1 passes with a given flow rate through the shut-off valve 5 through the pipe 2 through the process filter 8 (where particles of contaminants are partially deposited), a flow meter 9 (control the fuel consumption by the readings of flow meter 9 of filling line 2 and flow meter 13 of the sampling line). Part of the fuel comes from pipeline 2 through a sampling device 10 to a sampling line 11 containing a control filter 12, a flow meter 13, and returns to pipeline 2 after the throttling device 14. After filling the tank 4, close valves 5, 6 of the filling pipe 2 and shut-off valves 15 , 16 trunk selection.

3. Turn on the system of pressurizing the tank 4 of the product (configured to maintain a given flow rate of the liquid in the pipeline) and open the valves 7, 5 of the drain line and shut-off valves 24, 25 of the sampling line 21. Drain the fuel from the filled tank 4 through the drain line 3.

The fuel from the tank 4 passes through the pipeline 3 through the process filter 18 (where the bulk of the particles of dirt is deposited), a flow meter 19, a shut-off valve 5 and enters the refueling stand tank 1. At the same time, part of the fuel passes through the selection device 17 to the selection line 21, containing the control filter 20, the flow meter 22, shut-off valves 24, 25, and returns to the main stream in the pipe 3 after the throttle device 23. Monitoring the fuel consumption - according to the readings of the flow meters 19, 22.

After draining the fuel from the tank 4 into the refueling bench container 1, the valves 5, 7 of the drain pipe 3 and shut-off valves 24, 25 of the sampling line 21 are closed.

4. To determine the mass content of particles of contaminants in the liquid passing through the filling lines 2 and drain 3, the control filter 12 of the sampling line from the filling pipe 2 and the control filter 20 of the sampling line 21 from the drain pipe 3 are disconnected. After appropriate treatment, the contaminants are removed from the control filters and carry out their analysis, including determining the mass of deposited contaminants using correction factors, the values of which were obtained during preliminary work on setting the mode in the current.

5. Determine the mass of particles of contaminants in the fuel passing through the pipe 2 to the tank 4 of the product during the first filling of the tank

$$M_{H\mathrm{one}}=m_{2H\mathrm{one}}{k}_{tH}\left(\frac{V_{0H\mathrm{one}}}{V_{2H\mathrm{one}}}-\mathrm{one}\right),\left(3\right)$$

where M _H1 is the mass of particles of contaminants in the liquid (fuel) passed into the product tank 4 during the first filling, m _2H1 is the mass of particles of contaminants in the liquid passed through the sampling line 11 of the filling pipe deposited on the control filter 12 of the sampling line during the first filling ; V _0H1 - the volume of fluid passing through the pipeline 2 from the tank 1 to the tank 4 of the product during the first filling; V _2H1 is the volume of fluid passed through the selection line 11 from the filling pipeline and returned to the pipeline during the first filling of the tank, k _tH is the correction factor.

6. Determine the mass of particles of contaminants in the fuel that passed through the pipeline during the first discharge from the tank 4 products:

$$M_{C\mathrm{one}}=m_{2C\mathrm{one}}{k}_{tC}\left(\frac{V_{0C\mathrm{one}}}{V_{2C\mathrm{one}}}-\mathrm{one}\right),\left(\mathrm{four}\right)$$

where M _C1 is the mass of particles of contaminants in the liquid (fuel) passing through the drain line 3 from the tank 4 during the first discharge from the tank, m _2C1 is the mass of particles of contaminants in the liquid passing through the sampling line 21 of the drain pipe deposited on the control filter 20 sampling line at the first discharge, V _0C1 - the volume of liquid passed through the drain pipe 3 from tank 4 to the tank 1 at the first _drain , V _2C1 - the volume of liquid passed through the sampling line 21 from the drain pipe and returned to the pipeline at the first drain, k _tC is the correction factor.

7. Based on the data obtained, the mass of particles of contaminants ΔM ₁ removed from the tank 4 of the product during the first cleaning cycle "filling - discharge" is determined:

$$\Delta M_{\mathrm{one}}=M_{C\mathrm{one}}+m_{2C\mathrm{one}}-M_{H\mathrm{one}}\left(5\right)$$

(designations are given above)

8. During the second and subsequent cleaning cycles "filling and draining" receive data in accordance with expressions similar to (3-5),

$$M_{H2}=m_{2H2}{k}_{tH}\left(\frac{V_{0H2}}{V_{2H2}}-\mathrm{one}\right),\left(6\right)$$

$$M_{C2}=m_{2C2}{k}_{tC}\left(\frac{V_{0C2}}{V_{2C2}}-\mathrm{one}\right),\left(7\right)$$

$$\Delta M_2=M_{C2}+m_{2C2}-M_{H2}.\left(8\right)$$

9. The obtained mass values of the removed particles of contaminants and the volumes of liquid (fuel) are used to determine the volumes of liquid necessary to remove a given mass of contaminants from the tank. Using the results of the first filling-drain cleaning cycle, an equation is drawn up that determines the dependence of the mass of contaminants removed from the tank on the volume of liquid used

$$\frac{\Delta M_{\mathrm{one}}}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0{V}_{0H\mathrm{one}}}},\left(9\right)$$

and according to the results of the second cleaning cycle, they make up a similar equation taking into account the results of the first cycle

$$\frac{\Delta M_{\mathrm{one}}+\Delta M_2}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0\left(V_{0H\mathrm{one}}+V_{0H2}\right)}},\left(10\right)$$

where ΔМ ₁ , ΔМ ₂ is the mass of particles of contaminants removed from the tank after the first and second cleaning cycles ("filling - draining"), V _0H1 , V _0H2 are the volumes of the working fluid (fuel) used to fill the tank during the first and second cleaning cycles. Based on the results of two cleaning cycles, constant (at the selected cleaning modes) ΔM ₀ , A ₀ values (ΔM ₀ - initial pollution content in the tank) are determined. The volume of liquid V _0H required to remove from the tank a given mass ΔM of contaminant particles is determined using the equation

$$\frac{\Delta M_{\mathrm{one}}+\Delta M_2+\Delta M}{\Delta M_0}=\mathrm{one}-\frac{\mathrm{one}}{e^{A_0\left(V_{0H\mathrm{one}}+V_{0H2}+V_{0H}\right)}},\left(\mathrm{eleven}\right)$$

after which the next cleaning cycles are carried out with regimes similar to those of the first and second cleaning cycles, in order to achieve an acceptable value of the contaminant content in the tank.

The mass of particles of contaminants remaining in the tank after cleaning ΔM _ocm can be determined by the equation

$$\Delta M_{ocm}=\Delta M_0-\left(\Delta M_{\mathrm{one}}+\Delta M_2+...+\Delta M_n\right),\left(12\right)$$

where ΔM ₁ , ΔM ₂ , ..., ΔM _n is the mass of particles of contaminants removed from the tank during the first, second, ..., n-th cleaning cycles,

which is additional information for deciding on the feasibility of conducting final cleaning cycles.

Carrying out the operations for cleaning the working fluid when filling the tank and when draining it from the tank into the bench refueling tank allows you to repeatedly use the known volume of the same working fluid. This allows you to reduce the flow rate of the working fluid (expensive rocket fuel) necessary to achieve a given purity. In addition, due to the elimination of the need for installation work to connect and disconnect the drain tank, which is used as a bench refueling tank, the use of the method reduces the complexity of cleaning the tank level. Moreover, the assessment of the content of the mass of particles of contaminants in the fluid passing through the filling and discharge pipelines, the use of the method allows cleaning the tank of the rocket unit using the minimum number of fill-drain cycles to achieve a given degree of tank cleaning.

Claims (3)

1. The method of cleaning the fuel tanks of rocket blocks from particles of contaminants when preparing them for bench tests, which includes filling the tank with working fluid from the refueling bench tank, draining the working fluid from the tank into the drain bench tank, at the end of which the mass of particles of contaminants removed from the tank is determined, characterized in that after filling the tank with a working fluid, the mass of particles of contaminants entering the tank with the working fluid is determined, then the mass difference of the particles of contaminants removed from the tank during discharge and stepped into the tank during filling, determine the mass of particles of contaminants that were in the tank before filling it with a working fluid and removed when draining, and then spend the second cycle of filling the tank with working fluid and draining it from the tank to determine the mass of particles of contaminants entering the tank when filling with working liquid and being in the tank until the second filling with its working fluid and removed during the second discharge, then taking into account the masses of contaminant particles that were in the tank before each filling with its working fluid and removed at each drain, determine the mass of contaminant particles, which can be removed during subsequent filling-drain cycles, and clean the tank until the specified contaminant content in the tank is reached, while a filling stand tank is used as a drain stand tank to drain the working fluid, and when filling and draining the tank, the working fluid is passed through process filters. 2. The method according to claim 1, characterized in that the tank is filled with a working fluid through a filling pipe with a flow measurement and continuous sampling of a portion of the liquid from the filling pipe to the selection line through a control filter with a flow measurement and returning the filtered liquid to the filling pipe, and the mass particles of contaminants entering the tank with the working fluid, is determined taking into account the volume of fluid, determined by the measured values of the flow rate, according to the formula

,
where M _H1 is the mass of particles of contaminants in the liquid passed into the tank through the filling pipeline during the first filling, m _2H1 is the mass of particles of contaminants in the liquid passed through the pipe for selection of the filling pipe deposited on the control filter of the pipe selection pipe for the first filling, V _0H1 - the volume of liquid passed through the filling pipeline into the tank during the first filling, V _2H1 - the volume of liquid passed through the sampling line from the filling pipeline, a control filter of the sampling line and returned to the pipeline filling behind the throttle device during the first filling of the tank, k _tH - correction factor;
the working fluid is drained from the tank through a drain pipe with flow measurement and the continuous selection of part of the liquid from the drain pipe to another sampling line through a control filter with a measurement of its flow rate and the return of the filtered liquid to the drain pipe, and the mass of particles of contaminants removed from the tank is determined with taking into account the volume of liquid determined by the measured values of the flow rate, according to the formula

,
where M _C1 is the mass of particles of contaminants in the liquid passing through the drain pipe from the tank at the first discharge, m _2C1 is the mass of particles of contaminants in the liquid passing through the drain pipe selection line, deposited on the control filter of the drain pipe selection line at the first drain, V _0C1 - the volume of fluid passing through conduit drain from the tank during the first drain, V _2C1 - the volume of fluid passing along the selection line of the drain line, the control line selection filter and returned to the discharge conduit for the throttle device, k _tC - mandrel coefficient;
moreover, the mass of particles of contaminants ΔM ₁ , which were in the tank before filling it with a working fluid and removed when draining from the tank, is determined by the formula

;
after the second cycle of filling the tank with a working fluid and draining it from the tank, determine the mass of particles of contaminants entering the tank with the working fluid during the second filling, and the mass of particles of contaminants removed from the tank during the second discharge, taking into account the volumes of liquid determined from the measured flow rates, respectively according to the formulas

,

,
where M _H2 is the mass of particles of contaminants in the fluid passing through the filling pipe during the second filling of the tank, m _2H2 is the mass of particles of contaminants in the liquid passing through the pipe of the filling pipe deposited on the control filter of the selection pipe of the filling pipe during the second filling of the tank, V _0H2 - the volume of liquid that passed through the filling pipeline into the tank during the second filling, V _2H2 - the volume of liquid that passed through the sampling line from the filling pipeline, a control filter of the sampling line and returned to the pipe filling filler behind the throttle device during the second filling of the tank, k _tH is the correction factor, M _C2 is the mass of contaminant particles in the fluid passing through the drain pipe at the second discharge, m _2C2 is the mass of contaminant particles in the fluid passing through the drain pipe selection line, deposited in the control filter drain line selection line at a second draining fluid from the tank, V _0C2 - the volume of fluid passing through conduit drain from the tank at a second fluid draining from the tank, V _2C2 - the volume of fluid passing along the selection line of t uboprovoda drain and returned to the drain line for the second throttling device draining fluid from the tank, k _tC - correction factor,
determine the mass of particles of contaminants ΔM ₂ that were in the tank until the second filling it with a working fluid and removed during the second discharge from the tank, according to the formula

,
using the obtained values ΔM ₁ , ΔM ₂ are the equations that determine the dependence of the mass of particles of contaminants removed from the tank on the volume of liquid used,
for the first cleaning cycle:

,
for the second cleaning cycle:

,
as a result of the solution of which the constants ΔM ₀ , A ₀ (ΔM ₀ is the initial content of contaminants in the system) are determined constant (at selected cleaning modes), after which the mass of contaminant particles ΔM, which can be removed during subsequent cleaning cycles using the volume of working fluid, is determined V _0H , by the equation

and conduct tank cleaning to an acceptable value for the content of contaminants. 3. The method according to claim 2, characterized in that the flow conditions of the working fluid are preliminarily sequentially adjusted in the sections of the filling and discharge pipelines and in the corresponding lines for selecting a portion of the liquid to establish conditions for equal liquid velocities in the intake elements of the sampling devices and in the sections of the filling pipelines and discharge at the places of installation in them of devices for the selection of a part of the liquid by spilling them with the working fluid, measuring the flow rates of liquids in them, determining the mass of particles of contaminants deposited and control filter pipe sections fill and drain lines, and selection of the liquid, with which, taking into account the volume of liquid defined by the measured values of the costs determined correction coefficients k _tH, k _tC by formulas

,

,
where m _1tH is the mass of particles of contaminants in the liquid passing through the section of the filling pipeline during adjustment, deposited on the control filter of the drain line, m _2tH is the mass of particles of contaminants in the liquid passing through the line of sampling, deposited on the control filter of the line of selection of the section of the filling pipeline during tuning , V _0tH - the volume of fluid passing along the pipeline filling portion when setting, V _2tH - the volume of fluid passing through the pipeline selecting section when setting the filling conduit, m _1tC - mass of particles contaminated minutes in fluid passing over the site of the pipeline discharging when configuring deposited on a control filter drain line, m _2tC - weight contaminant particles in a fluid passed through line selection deposited on the test filter line selection drain conduit portion when setting, V _0tC - volume of liquid , which passed through the drain pipeline section during adjustment, V _2tC is the volume of fluid passing through the drain pipe section during adjustment.

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