RU2299375C1 - Method and device for distributing gas - Google Patents

Abstract

FIELD: storing or distributing gases or liquids.

SUBSTANCE: method comprises supplying gas from the high-pressure tank to consumers through the pipelines and connecting the outlet of the tank with collector. The air is supplied from the collector to the first supplying pipeline through the first sonic nozzle and valving member mounted downstream of the nozzle. The remainder supplying pipelines are supplied with air through the second and subsequent sonic nozzles provided with diaphragms mounted downstream of them. The air is distributed from each supplying pipeline over all consumers through the corresponding consuming sections. The diaphragms are broken out forcedly by the signal from the pressure gage mounted on the high-pressure tank. The device for distributing gas is also proposed.

EFFECT: improved environmental protection.

5 cl, 4 dwg,

Description

The invention relates to gas engineering and more specifically to methods and devices for distributing gas flow from a high pressure vessel to several consumers under conditions of high stable total flow and emptying the high pressure vessel for a limited time. Such methods and devices are used in testing models in high-speed wind tunnels, inert gas fire extinguishing systems, in devices for diluting accidental emissions of toxic substances in the chemical industry, as well as in afterburning systems for incomplete combustion of solid rocket fuels with air supplied from high-capacity tanks pressure during the utilization of solid rocket fuel charges by burning in a housing without a nozzle in a closed-type recycling plant.

When gas is supplied from the tank to the consumer’s main line through a flow restrictor with sound outflow (nozzle, diaphragm) of constant flow area, a pressure drop will occur in the high-pressure reservoir, with a decrease in flow rate, because during sound outflow the mass flow is a function of the pressure in front of the nozzle

where P is the pressure in front of the nozzle;

F is the critical sectional area of the nozzle;

G is the function of the gas adiabatic exponent;

R is the gas constant;

T is the absolute temperature.

A known method for the short-term supply of a large flow of air from a high-pressure tank or balloon group through a high-speed starting crane to a high-speed wind tunnel. Moreover, the time of action of such a pipe is limited by the time the flow falls within the tolerance, so that most of the accumulated air supply is not used [1].

Known methods of supplying gas from a high pressure tank to the consumer line through a gas pressure reducer, the throttling passage section of which varies depending on the pressure in the tank and the force of the springs, thus maintaining a predetermined constant flow rate [2]. Variants of this method are known in which the control valve has an electric actuator and a change in the flow area between the spool and the seat is due to the movement of the spool by an electric motor drive. Commands for the electric drive are generated using pressure sensors on the gas receiver and a signal converter. In this case, the mass of the spool does not have a significant effect, but the speed of movement depends on the dynamic characteristics of the electric motor, the gear ratio of the gear reducer, and the gear free travel [3]. A common disadvantage of this method is the inertia of the movable body of the gas reducer with powerful springs and a large mass at high flow rates and diameters of the highway, for example, when the diameter of the highway is 400 mm and the flow rate is 300-400 kg / s.

The closest in technical essence and adopted for the prototype is a method and device for supplying an inert fire extinguishing gas, such as nitrogen or a nitrogen-air mixture, to several fire hazardous objects when gas is consumed from a high-pressure tank. The device contains a high pressure tank, a gas distributor and pipelines to individual fire hazardous facilities, equipped with separate locking and gas distribution devices [4]. At the same time, there is no requirement to stabilize the total flow at a level always above the nominal, but with a minimum excess. The disadvantage of this gas distribution is the reduction in flow to individual objects depending on the time and gas extraction to other objects.

The technical problem solved in the present invention was the creation of a method and device for its implementation, providing continuous flow of air or gas from a high pressure tank with a stabilized total flow rate at a level always higher than the nominal, but with a minimum excess, the multiplicity of which is the volume of the tank in constant time is tens or hundreds of seconds. The expiration time constant (characteristic time) is determined

where V is the volume of the pressure vessel;

F _cr - the area of the critical section of the outlet nozzle;

and _nach is the speed of sound in air in the initial state of the high-pressure tank.

This technical task was posed when modifying the test bench for the utilization of solid-propellant rocket engines by burning in a non-fuel version described in the book by L.V. Zabelin, R.V. Gafiyatullin, A.N. Ponik, V.Yu. Meleshko. Fundamentals of industrial technology for the disposal of large solid propellant charges. - M .: Nedra, 2004, p. 83-88. An environmentally friendly version of the stand provides for the afterburning and neutralization of products of incomplete combustion in a gas-liquid ejector with the supply of afterburning air from high pressure tanks. The air in the gas-liquid ejector (GJE) must come with such a nominal flow rate that provides almost complete afterburning. However, emptying the pressure vessels through simple shut-off devices does not allow for a stable air flow into the gas-liquid ejector, so that, for example, with a constant flow of products of incomplete combustion, the completeness of afterburning will change from required to insufficient or, in another embodiment, the amount of supplied afterburning air will be excessive almost the entire time of burning solid fuel, but this will require a significantly overestimated initial volume of air in the high-pressure tank, and gas the liquid ejector will operate at high speed modes, as a result of which the residence time of gas and air in the channel of the gas-liquid ejector for complete afterburning will be insufficient. In addition, a significant portion of the air supply will not be used.

The solution of the technical problem was achieved in that in a method for distributing gas flow to consumers in a system consisting of a high pressure gas source and consumer pipelines connected to it, including supplying gas from a high pressure tank through consumer pipelines, characterized in that they are connected through a valve the output of the final volume tank with a collector, air from which is supplied to the first feed pipe through the first sound nozzle and the starting locking means installed behind it, and air is supplied to the remaining supply pipelines through the second and subsequent sound nozzles with shock-free shatterproof pyromembranes installed behind them, air from each feed pipe is distributed to all consumers through the corresponding consumption sections, shock-free shatterproof pyromembranes are forcedly burst by the signals of the pressure sensor on the high-pressure vessels, and the distribution pressure response of the sensor is set using a selection of tuning factors that determine the calculated reduced pressure and flow rates through passage sections of sound nozzles to the ends of the calculated time sections of the gas flow distribution device operation period, the number of supply pipelines is equal to the number of calculated time sections, when the starting shut-off device of the first pipeline is opened, the initial gas flow rate is set higher than the nominal one in accordance with the setting factor by the breakthrough of the first and each subsequent shock-free shatterproof pyromembrane, the flow rate is taken equal to the nominal, after the breakthrough of the shock-free shatterproof In the case of a pyromembrane, the flow rate is overestimated by the tuning factor, the discharge is cut off by closing the valve in front of the collector. When the shut-off device is opened, the gas flow rate is set 1.5 times higher than the nominal value. The adjustment coefficients are set the same for all time sections of the period of operation of the gas flow distribution device. The adjustment factors are set different in time sections of the period of operation of the gas flow distribution device.

A device for distributing gas flow rates to consumers, comprising a high-pressure container and consumer pipelines with shut-off and distribution means, characterized in that the high-pressure tank is connected through a valve to a manifold to which the feed pipelines are connected, the first feed pipe is provided with a first sound nozzle and downstream from it starting locking means, the second and subsequent feed pipelines are equipped with second and subsequent sound nozzles and downstream of their shock-free shatterproof pyromembranes, each feed pipe is divided into pipes by the number of consumers, pipes from each feed pipe are connected to each consumer. The second and subsequent consumer pipelines downstream of the impactless shatterproof pyromembranes are connected to the first consumer pipeline through backpressure jets in the consumer outlet collectors.

A comparative analysis of the essential features of the prototype and the proposed method shows that the distinctive essential features of the proposal are those in accordance with which:

- the output of the high pressure vessel through the valve is connected to the manifold;

- air from the collector to the first feed pipe is fed through the starting locking means and the sound nozzle installed behind it;

- air from the collector to the remaining feed pipelines is fed through sound nozzles and pyromembranes installed behind them;

- air from each feed pipe is distributed to all consumers through the consumption section;

- membranes break through forcibly by signals from a pressure sensor on a high-pressure tank.

The essence of the present invention will be clear from a consideration of the drawings, where:

figure 1 is a General diagram of the air supply to the gas-liquid ejector of the present invention;

figure 2 shows a graph of the pressure reduction in the high pressure vessel while maintaining the total constant flow rate in the GLC using pyromembranes together with sound nozzles,

figure 3 represents the estimated air flow at uncontrolled outflow from the high-pressure tank and expiration through successively connected sound nozzles of the present proposal in comparison with the flow of combustion products and the required nominal air flow for them,

and the following description of an example embodiment of the invention.

As shown in FIG. 1, the afterburning air supply system of a modified solid fuel rocket engine utilization stand by combustion in a non-nozzle embodiment includes a gas-liquid ejector 1 with three afterburning air supply sections 2, 3, 4, a high-pressure tank battery 5 connected through a valve 6 with a collector 7. From the collector 7, the first pipe 8 with a locking device 9 and the first sound nozzle 10, the second pipe 11 with an unshocked non-fragmentation pyromembrane 12 and the second sound nozzle 13 and the third pipe 1 4 with an impactless shatterproof pyromembrane 15 and a third sonic nozzle 16. In front of the gas-liquid ejector 1 having three sections of the afterburning air supply 2, 3, 4, each of the pipelines 8, 11 and 14 is divided into three pipes 8-2, 8-3, 8 -4, 11-2, 11-3, 11-4, 14-2, 14-3, 14-4, which are connected to the corresponding sections 2, 3 and 4. Sections 2, 3 and 4 have, respectively, three each collector with rows of distribution output nozzles or holes (not shown) for uniform distribution of the supplied afterburning air over the internal volume of the gas-liquid ejection channel a. The battery of high-pressure vessels is equipped with pressure sensors 17 and temperature sensors 18. The feed lines 11 and 14 are connected through the nozzles 19 and 20, respectively, with the first feed pipe 8.

During operation of a modified disposal facility for burning a solid propellant rocket engine with a fuel mass of 25,000 kg, air is pumped to a pressure of 3.0 MPa into a high-pressure tank or a battery of tanks of 5 with a total volume of 2,400 m ³ . The work of the stand begins by blowing the channel of the gas-liquid ejector with air from the high-pressure vessel for 30 s through the valve 6, the collector 7 and the first pipe 8 with an open starting shutoff means 9 and through the sound nozzle 10 with a maximum flow rate of 1.5 times the nominal afterburning rate . After that, the solid propellant is ignited and incomplete combustion products enter the channel of the gas-liquid ejector. The afterburning air enters the channel of the gas-liquid ejector through the outlet nozzles of the collectors of sections 2, 3, 4 through the pipes 8-2, 8-3, 8-4 from the feed pipe 8. Through the feed pipes 11 and 14 through the nozzles 19 and 20 from the feed pipe 8 backpressure air flows through pipes 11-2, 14-2 into the collectors of section 2, through pipes 11-3, 14-3 into the collectors of section 3 and through pipes 11-4, 14-4 into the collectors of section 4 to prevent hot products of combustion through the outlet nozzles to the manifolds and the destruction of the nozzles. When the pressure in the high-pressure vessel 5 decreases to a value at which the air flow corresponds to the nominal afterburning air flow, for example, 348 kg / s passing through the first sonic nozzle f], a command is issued to actuate the first shock-free non-fragmentation pyromembrane 12 and air to the gas-liquid ejector it starts to flow through two sound nozzles with critical cross-sections F ₁ and F ₂ through two feed pipelines 8 and 11 with a 1.5 times increased flow rate compared to the nominal one. The pipeline 14 through the nozzle 20 continues to receive air with a low flow rate through pipes 14-2, 14-3, 14-4 in the collectors of sections 2, 3, 4, respectively. If the pressure in the high-pressure tank or battery of tanks 5 is further reduced to a value at which the air flow corresponds to the nominal afterburning air flow, passing in total through the sound nozzles F ₁ + F ₂ , a command is issued to trigger the second shock-free non-fragmentation pyromembrane 15, and the afterburning air the gas-liquid ejector enters through three sonic nozzles 10, 13 and 16 through three feed pipelines 8, 11, 14 with a 1.5 times increased flow rate compared to the nominal through the total critical cross-sectional area F ₁ + F ₂ + F _3.

As shown in figure 2, in accordance with the method, the entire combustion period is divided into several calculated sections for the pressure drop by setting tuning factors, for example 1.5. The tuning factor is defined as the ratio of the initial pressure or initial flow rate in the area to the final pressure or flow rate in the area, since m _start / m _con = P _start / R _con . The lower the coefficient of adjustment, the closer the maximum flow rate from the battery of high-pressure vessels to the nominal, however, the greater will be the number of sections of the pressure drop in a given period of combustion. In the first section, air enters the GLC through the minimum critical cross-sectional area F _cr ′, which provides air at the initial moment with a certain excess relative to the nominal flow rate, for example, by 1.5 times in accordance with the tuning factor. At the end of this time period, when the pressure in the pressure vessel drops 1.5 times, the mass air flow will be equal to the nominal. The second time section begins with an increased critical cross-sectional area F ′ _cr + F _cr ′ ′, for example, by 1.5 times, with respect to F _cr ′ due to the connection of the second sound nozzle with F ′ ′ _cr . As a result, the mass flow rate will increase to 1.5 of the estimated flow rate, and then, at the end of the temporary section, the mass flow rate will decrease to the calculated one if the pressure at this point is 1.5 times less than the pressure at the beginning of this temporary section. The next time section is assigned in the same way, with an increase by the coefficient of adjustment of the critical section area, for example, by 1.5 times in relation to F ′ _cr + F _cr ′ ′. At the end of the last time section, the mass flow rate will be equal to the calculated one if the final pressure is at least two times higher than the pressure in the GLC. The number of feed pipelines is equal to the number of estimated time sections. Figure 3 shows the changes in time of afterburning air flow rates when it expires from a high-pressure vessel through one sound nozzle with a constant critical section and an initial flow rate of 522 kg / s (curve 1), through one sound nozzle with an initial nominal flow rate of 348 kg / s (curve 2), through successively connected sound nozzles of this proposal (curve 3) in comparison with the nominal air flow rate required for afterburning (curve 4) and the time-averaged flow rate of combustion products (curve 5).

The table gives an example of calculating the areas of critical sections for temporary sections and the durations of temporary sections for solid-state solid-propellant rocket engines of the first stage with a nominal air flow rate of 348 kg / s and an initial calculated critical section area for a nominal flow rate F _cr = 0.04973 m ² . The initial pressure in the high pressure vessel is 3.0 MPa, the volume of the high pressure vessel is 2400 m ³ . An instant increase in the total critical cross-sectional area can be achieved by using parallel inlets equipped with shock-free shatterproof pyromembranes in the GLC. It does not require large expenses. Management of shock-free shatterproof pyromembranes can be carried out according to the estimated times of the sections with additional control by pressure sensors. When triggered shock-free shatterproof pyromembranes do not form an air shock wave and there are no flying fragments inside the pipeline. Using tuning factors, the air supply system can be optimized, for example, in temporary sections, by the maximum final pressure in the high-pressure vessel at the end of the combustion, by the minimum excess of air, etc. The adjustment factors for the plots can be the same or different.

Table Calculation example of a system for step-by-step setting of air flow in the GLC Options Plots one 2 3 Tuning factor 1,5 1,5 1.7 Initial flow rate, kg / s 522 522 591.6 Final consumption on the site 348 348 348 Initial pressure on the site, MPa 3 2 1.33 The final pressure on the site, MPa 2 1.33 0.782 F _cr on the plot, m ² 0,07459 0,11189 0.1902 The time constant t _xap on the plot, s 97.5 65 38,2 Duration of the site, s 68.3 45.53 35.06

The use of relative durations t / t _{xap of} time sections on the system operation diagram of less than 1 allows one to obtain an almost linear piecewise smooth dependence of the pressure drop in the high-pressure vessel on the system operation time. This follows from the exponential dependence of the capacity emptying on time, the expansion of which in a series at t * <1 gives:

P * = 1-At * + (At *) ^2/2,

where the third term of the expansion is significantly smaller than the second and may not be taken into account. Here P * = P / P _beg ; t * = t / t _xap .

Unlike a device with sound nozzles connected sequentially in time to a single feed pipe, this proposal allows eliminating flow shocks during the operation of shock-free shatterproof pyromembranes in all collectors of consumer sections except one. In addition, the flow peak during the operation of an impactless shatterproof pyromembrane is smoothed when the corresponding feed pipe, pipes and collectors of consumer sections are filled. With regard to the processes of afterburning of combustion products, this allows to eliminate air leakage without interacting with products of incomplete combustion.

The implementation of this proposal in the construction of a booth for the utilization of solid propellant rocket engines by burning in a non-nozzle version allows more fully use the accumulated stock of high pressure air with high completeness of afterburning during the entire operation of the rocket engine.

The implementation of this proposal in the design of a gas fire extinguishing system for flammable objects allows for the supply of insulating gas with a high flow rate both when a fire is detected and at the final moment, which eliminates the possibility of re-ignition.

Information sources

1. A.K. Martynov. Experimental aerodynamics. M .: Oborongiz 1958, p. 105, Fig. 5.15.

2. N.M. Belyaev, N.P. Belik, E.I. Uvarov. Reactive aircraft control systems. M.: Mechanical Engineering 1979, p. 45, Fig. 2.5.

3. EP 1336795, 2003.

4.JP 2004130054, 2004

Claims (5)

1. A method of distributing gas flow to consumers in a system consisting of a high pressure gas source and consumer pipelines connected to it, comprising supplying gas from the high pressure reservoir to consumer pipelines, characterized in that the outlet of the high pressure reservoir is connected to the manifold via a valve, air from which the first feed pipe is fed through the first sound nozzle and the starting locking means installed behind it, and air is fed into the remaining feed pipes through the second subsequent sound nozzles with shock-free non-fragmentation pyromembranes installed behind them, air from each feed pipe is distributed to all consumers, shock-free non-fragmentation pyromembranes are forced to break through the pressure sensor signals at high pressure vessels, and the pressure distribution of the response of the sensor is set using a selection of tuning factors that determine the calculated reduction pressures and flows through passage sections of sound nozzles at the ends of the calculated time sections period the operation of the gas flow distribution device, the number of supply pipelines is equal to the number of calculated time sections, when the starting shut-off device of the first pipeline is opened, the initial gas flow rate is set higher than the nominal one in accordance with the tuning factor, before the breakthrough of the first and each subsequent shock-free non-fragmentation pyromembrane, the flow rate is assumed to be nominal, after the break shock-free non-fragmentation pyromembrane flow rate is overestimated by the setting factor, the discharge is cut off by closing the rear buckle front of the collector. 2. The method of distributing gas flow rates according to claim 1, characterized in that when opening the starting shut-off means, the gas flow rate is set 1.5 times higher than the nominal value. 3. The method according to claim 1, characterized in that the tuning coefficients are set the same for all calculated time sections of the period of operation of the gas flow distribution device. 4. The method according to claim 1, characterized in that the tuning factors are set different in the calculated time sections of the period of operation of the gas flow distribution device. 5. A gas flow distribution device comprising a high-pressure container and consumer pipelines with shut-off and distribution means, characterized in that the high-pressure tank is connected through a tap to a manifold to which the feed pipelines are connected, the first feed pipe is provided with a first sound nozzle and downstream from it starting locking means, the second and subsequent feed pipelines are equipped with second and subsequent sound nozzles and downstream of them shock-free without with split pyromembranes, each feed pipe is divided into pipes by the number of consumers, pipes from each feed pipe are connected to each consumer, and the second and subsequent feed pipes of consumers downstream of the shock-free split pyromembranes are connected to the first feed pipe through backpressure nozzles in the consumer outlet manifolds .

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