RU2488040C1 - Device for local supply of energy to air flow streamlining around object (versions) - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: device for local energy supply to an air flow streamlining around an object comprises a channel for a flow of a hydrogen-containing gas and an air flow, an electric discharge device, and also a system of power supply and monitoring of discharge parameters, the electric discharge device is installed so that only the hydrogen-containing gas is exposed to electric discharge, at the same time the system of power supply and discharge parameter monitoring is selected so that the glow discharge is implemented with the ratio of electric field intensity E to the gas pressure P equal to $$\frac{E}{P}=\left(130-170\right)\frac{B}{mix\cdot "Tорр"},$$

and downstream the zone of electric discharge there is a device installed to mix the hydrogen-containing gas enriched with radicals H with the air flow.

EFFECT: invention makes it possible to increase efficiency of electric discharge exposure at fuel burning as it is mixed with an oxidant at low static mixture temperature, and also to accelerate burning reaction.

2 cl, 5 dwg

Description

The invention relates to the field of aerodynamics and to power plants of various objects, for example, vehicles, and can be used to improve the aerodynamic quality of objects by supplying energy to their outer surface.

A device for supplying energy to an air stream due to the combustion of propane ejected into the stream from the holes in the model, taken as a prototype [work V.Skvortsov, Yu.Kuznetsov, V.Litvinov, et al. Investigation of aerodynamic Effects at the Electric Discharge Creation on the Models of Different Geometry. The second Workshop on Magneto - Plasma - Aerodynamics in Aerospace Applications. M., April 5, 2000, p. 102].

The device contains an ejector to create an air stream and an injector for admitting a hydrogen-containing mixture into this stream, as well as electrodes fixed in the walls of the working channel for the implementation of an electric discharge, by which the hydrogen-containing mixture is ignited.

The disadvantages of this device are the appearance of inhomogeneities in the field of the working gas stream, including inhomogeneous filling of the stream with combustion products, high energy costs for the breakdown of the discharge gap in a fast flowing stream; incomplete combustion of fuel in the observation zone due to the commensurability of the time of chemical reactions during combustion and the time of macrodisplacement of the gas volume.

The objective and technical result of the invention is to increase the efficiency of the effect of an electric discharge on ignition of a fuel when it is mixed with an oxidizing agent (air) at a low static temperature of the mixture, as well as accelerating the combustion reaction.

The solution of the problem and the technical result are achieved by the fact that in the device for the local supply of energy to the air stream flowing around the object containing the channel for the stream of hydrogen-containing gas, devices for creating a stream of hydrogen-containing gas and air stream, an electric discharge device, an electric power supply system and control of electric discharge parameters, an electric discharge device It is established that only hydrogen-containing gas is exposed to electric discharge, while the power supply and parameter control system s electrodischarge chosen so that glow discharge was carried out with a ratio of the electric field E to the pressure P equal to:

$$\frac{E}{P}=\left(130-170\right)\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR},$$

and behind the electric discharge zone, a device is installed for mixing a hydrogen-containing gas enriched in an electric discharge with H radicals and an air stream.

The solution of the problem and the technical result are also achieved by the fact that in a device containing a channel for a stream of hydrogen-containing gas, devices for creating a stream of hydrogen-containing gas and air flow, an electric discharge device, as well as a power supply system and control of electric discharge parameters, at high flow rates of hydrogen-containing gas and air, for example , in the scramjet, in the channel for supplying hydrogen-containing gas, a nozzle array and / or pylons in which nozzles are installed, each nozzle being an electric discharge the device using the nozzle body and the rod passing through the critical section as electrodes, the power supply of all discharges in the nozzles is independent, and the power supply and parameter control system for each discharge provides the ratio:

$$\frac{E}{P}=\left(130-170\right)\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR}.$$

and behind the electric discharge zone, a device is installed for mixing a hydrogen-containing gas enriched in an electric discharge with H radicals and an air stream.

The optimal values of the E / P discharge to obtain the maximum concentration of H radicals are known from the literature, for example, [G. Messi and E. Barkhop. Electronic and ionic collisions. IL., Moscow, 1958, p. 603].

Schemes and graphs illustrating the invention are shown in figures 1, 2, 3, 4, 5.

The figure 1 shows a diagram of a device with a single glow discharge and using gaseous hydrogen as fuel.

The figure 2 shows the dependence of the heat flux Q obtained by the combustion of hydrogen, and the increase in gas temperature ΔT on pressure.

Figure 3 shows a diagram of a device for high flow rates of hydrogen-containing mixtures when a nozzle array is used.

Figure 4 shows a single element of the nozzle array.

Figure 5 shows the placement of the nozzles on the fuel pylons with a cross section A showing the element of the nozzle.

The device with a single glow discharge, shown in figure 1, contains a working chamber 1 of the wind tunnel, which contains the elements of the device used to accelerate the combustion of hydrogen: an electric discharge tube 6 with electrodes 7, 9 and a power source 10, grid 8 for mixing fuel with air , then a mixing chamber 11 is installed, which is docked with a meter (calorimeter) of heat 4 generated during combustion. At the outlet of the heat meter 4, a gas ejector is installed, which ends the gas exhaust channel 5. The device is equipped with gas flow meters 3, pressure meters 2, through VA the atmospheric air inlet to the working part is shown,

N ₂ - the flow of gaseous hydrogen, VD - the flow of high pressure air into the ejector.

T - gas temperature meter.

The operation of the device is as follows.

Air VA from the atmosphere is fed into the mixing chamber 11 due to the pressure drop created by the ejector system. Air flow rate is measured by a flow meter 3. Hydrogen H ₂ from the cylinders is fed into an electric discharge tube 6, the pressure of which is measured by a pressure gauge 2. An electric discharge is ignited in the electric discharge tube 6, applying voltage to the electrodes 7, 9. The voltage V is measured at the discharge gap and the voltage is determined electric field E. Adjust V and P so that the ratio E / P is equal

$$\frac{E}{P}=\left(130-170\right)\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR}.$$

In experiments on the ignition of hydrogen in a mixture with atmospheric oxygen, the combustion products were sent to the channel of the calorimeter 4. We measured the change in pressure in the working chamber of calorimeter 2 and the temperature ΔT of the flow at the outlet of the calorimeter.

Let us give an example of flow parameters, electric discharge, energy release in one of the experiments.

A glow discharge was implemented with the following parameters: voltage U = 5 kV, current I = 10 ^-2 A. The hydrogen pressure in the chamber was 2 · 10 ⁴ Pa, the hydrogen flow rate was 0.02 g / s. Attitude $$\frac{E}{P}\approx 160\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR}.$$

The heat flux generated during the combustion of hydrogen was measured with a calorimeter operating on the principle of a gas thermometer. The power transmitted from the flow to the walls of the calorimeter is

, $$W=C\cdot m\cdot \frac{dTw}{dt}$$

,

where C, m - heat capacity and mass of the calorimeter,

Tw is the temperature of the outer surface of the heat-sensing cylinder of the calorimeter.

The total power released during combustion is:

Q = W + G · C _p · ΔT,

where C _p , G - heat capacity and flow rate of the gas mixture,

ΔT is the change in gas temperature at the outlet of the calorimeter.

The contribution of energy to heating from an electric discharge is estimated. It is negligible compared to the heat generated by the combustion of hydrogen.

The experiments showed that during the implementation of fuel combustion by the proposed method, hydrogen ignition occurred at a flow temperature of T≈300 K and a pressure of P≈0.7 · 10 ⁵ Pa.

Under these conditions, fuel combustion occurred completely over the length of the calorimeter, which is ~ 0.5 m. In this case, the flow velocity at the inlet to the calorimeter was ~ 200 m / s.

From the experiments it can be seen that the proposed device is effective, firstly, from the point of view of reducing the temperature of the air at which the ignition of the fuel occurs. So in an experiment, fuel ignites at room temperature, while in the experiments described in the literature, under similar other conditions, fuel (hydrogen) ignited at a temperature of T≈900 K, see, for example, [A. Yoshida, G. Sui. Supersonic combustion of hydrogen in an air stream. RTK, No. 4, 1997, p.18]. Secondly, the rate of fuel combustion increases so much that the dimensions of, for example, an engine such as a scramjet engine ~ 2.5 m become quite sufficient for complete combustion of the fuel. So, when recalculating the size of the combustion chamber used in the above experiment to the size of the combustion chamber in the scramjet, where the air flow rate is ~ 10 ³ m / s, we get the size of the combustion chamber of the engine ~ 2.5 m, which is easily realized.

весьма проблематично, поэтому поток делят на несколько потоков (струй) с помощью решетки сопл, при этом каждое сопло является электроразрядным устройством с электродами, например, один электрод - корпус сопла, другой электрод - стержень, проходящий через критическое сечение сопла; параметры потока газа через каждое сопло выбирают из условия реализации указанного отношения Е/Р, независимость электропитания разряда в каждом сопле обеспечивается или путем применения независимых источников питания или устройством балластных сопротивлений.At large dimensions of the working channel (high costs of a hydrogen-containing mixture), ignition of a discharge of a given type (thermally nonequilibrium glow discharge) with given parameters $$\left(\frac{E}{P}\approx 160\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR}\right)$$

very problematic, therefore, the flow is divided into several streams (jets) using a nozzle array, with each nozzle being an electric-discharge device with electrodes, for example, one electrode — the nozzle body, another electrode — a rod passing through the critical section of the nozzle; the parameters of the gas flow through each nozzle are selected from the conditions for the implementation of the specified E / P ratio, the independence of the discharge power supply in each nozzle is ensured either by using independent power sources or by a ballast device.

The figure 3 presents a diagram of the device at high flow rates of the supplied hydrocarbon gas, on which

1 - prechamber;

2 - device with ballast resistances;

3 - lattice of nozzles with preionizers 4;

5 - a chamber for mixing a hydrogen-containing gas with air;

6 - zone (chamber) of hydrogen combustion;

7 - electrodes.

8 to the pre-chamber 1, a hydrogen-containing gas is supplied, then it enters the nozzle array 3 with the preionizers 4 mounted on them. An electric glow discharge is ignited between the electrodes 7 and the nozzle wall, which is the second electrode (not shown in FIG.). Next, the hydrogen-containing gas enters the mixing chamber 5, and then the mixture of the hydrogen-containing gas and air enters the combustion chamber 6. The ballast resistances 2 consist of separate elements for each of the discharges, respectively. The nozzle body serves as one of the electrodes.

A diagram of the nozzle array element is shown in FIG. 4, in which:

1 - nozzle - anode;

2 - wall;

3 - mount;

4 - cathode;

5 - ballast resistance;

6 - glow discharge power supply.

Hydrogen-containing gas enters the nozzle 1, the walls of which are the anode. An electric glow discharge is ignited between the anode 5 and the cathode 4. The nozzle is attached to the wall of the chamber 2. Ballast resistance is used for stable discharge burning 5. The discharge circuit is powered from the glow discharge power supply 6.

The nozzle array will be used at subsonic flow rates at the device inlet. At supersonic speeds in the combustion chamber, for example in the case of scramjet engine, electric-discharge devices and nozzles are placed in fuel pylons mounted on its walls. The mixture of fuel and air occurs in jets behind the fuel pylon.

The layout of nozzles on a fuel pylon with a cross section A showing the nozzle element is shown in FIG. 5

Nozzles are installed on the backstream edge of the fuel pylon; each is supplied with power from an independent source and a hydrogen-containing gas. The outflow from the nozzles occurs in the bottom wake of the fuel pylon, where the jets mix. The number of nozzles mounted on one fuel pylon is determined from design considerations.

The proposed device for the local supply of energy to the air flow around the aircraft, or to the air flow in the engine allows you to:

- to prepare the fuel for combustion by generating active H radicals in it, passing the fuel through the glow electric discharge zone with the value $$\frac{E}{P}\approx 160\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR};$$

- carry out the ignition of hydrogen or hydrocarbon fuel at temperatures close to room temperature and below atmospheric pressure;

- increase the rate of combustion of fuel mixed with air, which is fundamentally important for the development of engines such as scramjet engine.

Claims (2)

1. A device for the local supply of energy to the flow of air flowing around an object containing a channel for a stream of hydrogen-containing gas, devices for creating a stream of hydrogen-containing gas and air flow, an electric discharge device, as well as a power supply system and control of electric discharge parameters, characterized in that the electric discharge device is installed so that only a hydrogen-containing gas is exposed to the electric discharge, while the power supply system and control of the electric discharge parameters are selected as so that a glow discharge is realized with a ratio of the electric field strength E to pressure P equal to
$$\frac{E}{P}=\left(130-170\right)\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR},$$

and behind the electric discharge zone, a device was installed for mixing a hydrogen-containing gas enriched in an electric discharge with H radicals and an air stream. 2. A device for the local supply of energy to the flow of air flowing around an object containing a channel for a stream of hydrogen-containing gas, devices for creating a stream of hydrogen-containing gas and air flow, an electric discharge device, as well as a power supply system and control of electric discharge parameters, characterized in that at high costs of hydrogen-containing gas and air, for example, in a gas scramjet, a nozzle array is installed in the channel for supplying hydrogen-containing gas, and nozzles are installed in the supersonic combustion chambers in the fuel x pylons, wherein each nozzle is an electric discharge apparatus using as electrodes passing through the throat of the nozzle body and the rod, power supply nozzles discharges in all independent, the power supply system and the control parameters of each electric discharge ensures ratio
$$\frac{E}{P}=\left(130-170\right)\frac{B}{\mathrm{from}m\cdot T\mathrm{about}RR},$$

and behind the electric discharge zone, a device is installed for mixing a hydrogen-containing gas enriched in an electric discharge with H radicals and an air stream.

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