WO2014178745A1

WO2014178745A1 - Method for enhancing the detonability of a liquid hydrocarbon fuel

Info

Publication number: WO2014178745A1
Application number: PCT/RU2013/000373
Authority: WO
Inventors: Сергей Михайлович ФРОЛОВ; Федор Сергеевич ФРОЛОВ; Сергей Николаевич МЕДВЕДЕВ
Priority date: 2013-04-30
Filing date: 2013-04-30
Publication date: 2014-11-06

Abstract

The invention relates to liquid hydrocarbon fuels for various technical devices and power plants operating by controlled detonation combustion in a pulsed or continuous detonation mode. Proposed is a method for delivering a liquid hydrocarbon fuel to a combustion chamber of a burner device or engine operating by controlled detonation, which includes the separate or combined distributed delivery of a liquid hydrocarbon fuel and an additional fuel, namely gaseous hydrogen, to a combustion chamber, providing, on average, a uniform spatial distribution of liquid hydrocarbon fuel droplets and also of concentrations of hydrogen and air in the detonation initiation and propagation region, wherein the minimum concentration of hydrogen in the detonation initiation and propagation region must be more than 4% vol. if the degree of pre-evaporation of the liquid hydrocarbon fuel inside the combustion chamber prior to arrival of the detonation wave is not greater than 20-25%, and more than 3% vol. if the degree of pre-evaporation of the liquid hydrocarbon fuel inside the combustion chamber prior to arrival of the detonation wave is greater than 25%. The liquid hydrocarbon fuel and hydrogen may enter the combustion chamber separately in the form of distributed streams, or together in the form of a heterogeneous fuel mixture formed by bubbling hydrogen into the fuel.

Description

METHOD FOR INCREASING DETONATION ABILITY OF LIQUID HYDROCARBON FUEL

Technical field

The invention relates to liquid hydrocarbon fuels for various technological devices and power plants operating on controlled detonation combustion in pulse detonation or continuously detonation mode.

State of the art

The basic requirements for liquid hydrocarbon fuels for promising technological devices and power plants operating on controlled detonation combustion are formulated in (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), p. 624). These include: (1) the ability of liquid hydrocarbon fuels to detonate in a mixture with air over a wide range of temperatures, pressures and compositions of the combustible mixture and (2) the resistance of the fuel-air combustible mixture to premature self-ignition or ignition from a hot surface at temperatures up to 600-800 TO.

Regular liquid hydrocarbon fuels (gasoline, kerosene, diesel fuel, etc.), generally speaking, do not satisfy these requirements.

It is known (GD Roy, SM Frolov, Α.Α. Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), p. 624) that the detonation ability of regular liquid hydrocarbon fuels in air is very low: the critical mass of an explosive for direct initiation of detonation in homogeneous air mixtures of hydrocarbon vapors under normal conditions exceeds 50-60 g of TNT, and the detonation limits of such mixtures are very narrow and limited by compositions differing by only a few volume percent by fuel concentration. If detonation is initiated in a heterogeneous (droplet) mixture of regular hydrocarbon fuel in air, then a TNT charge of a mass exceeding hundreds of grams is needed, and the critical charge mass will be determined by the degree of preliminary evaporation of liquid hydrocarbon fuel before the detonation wave (vapor mass ratio) fuel to the total mass of fuel in the liquid and vapor phase). Therefore, the initiator energies (explosive, wire explosion, electric discharge, etc.) required to obtain heterogeneous (droplet) detonation of regular hydrocarbon fuel mixtures in air are too high for use in technological devices and power plants operating on controlled detonation combustion.

Air mixtures of regular hydrocarbon fuels have a relatively low resistance to self-ignition and ignition by hot surfaces at temperatures up to 600-800 K: alkaline hydrocarbons, which undergo multi-stage self-ignition with a manifestation of a negative temperature coefficient of the reaction rate, occupy a large proportion of regular hydrocarbon fuels. This, in particular, explains the occurrence of “knocking” in a piston engine with spark ignition, which is caused by pre-flame self-ignition of a charge in an off-design mode of operation.

Various methods are known for increasing the detonation ability of liquid hydrocarbon fuels.

One method is based on the preliminary thermal preparation of liquid hydrocarbon fuel outside the combustion chamber by partially or completely evaporating the fuel (Frolov S. M., Basevich V. Ya., Posvianskii VS Limiting Drop Size and Prevaporization Degree Required For Spray Detonation. In: Application of Detonation to Propulsion / G. Roy, S. Frolov, J. Shepherd Eds., Moscow, Torus Press, 2004, p. 1 10-1 19; Eurasian patent 010875 Bl, B01J 19/24; B01B 1/00 (2006.01) , 13.12.2005), partial or complete fuel pyrolysis (Bezgin LV, opchenov VI, Starik AM, Titova NS Modeling studies of ignition and combustion of propane and the products of the thermal decomposition. In: Pulse and Continuous Detonations (GD Roy, SM Frolov, JO Sinibaldi, Eds.). Moscow: Torus Press, 2006), and partial oxidation of fuel (Basevich V. Ya., Lidsky B.V., Frolov SM. Reducing the length of the pre-detonation section in a chemically prepared gas mixture: the Shchelkin-Sokolik effect. In the book Combustion and Explosion / edited by SM. Frolova. Moscow: Torus Press, 2009, Vol. 2, p. 22-25; Higgins AJ, Pinard P., Yoshinaka A. C, Lee JHS, Sensitization of fuel-air mixtures for deflagration-to-detonation transition. In: High-Speed Deflagration and Detonation: Fundamentals and Control (GDRoy, SM Frolov, D.Netzer, AA Borisov, Eds), ELEX-M Publishers, Moscow, 2001, 384 p.). Common disadvantages of this method are the complication of the design of the fuel supply system and the change in the state of aggregate fuel from liquid to gaseous, which leads to a decrease in the heat stress of the working process in the combustion chamber of the energy-converting device.

Another method is based on the modification of liquid hydrocarbon fuels by adding promoting additives that reduce the delay time of self-ignition and, thereby, increase the detonation ability of the fuel (patents RU 2444560 CI, C 10L 1/10, C10L 1/12 (2006.01), 07/01/2010; RU 2352618, C10L 1/12, C10L 10/02, C01F 17/00, 04/20/2009; RU 2352618, C10L 1/12, C10L 10/02, C01F 17/00, 04/20/2009; RU 2259388, C10L 1 / 12, 08/27/2005; Tepper F., Kaledin LA Nano aluminum as a combustion accelerant for kerosene in air breathing systems / 39th AIAA Aerospace Sciences Meeting & Exhibit 8-1 1 January 2001, Reno, NV, AIAA-2001-0521; Gerstein M., Choudhury PR, Programmed Ignition of Metal Compounds in a Scramjet / JANNAF Combustion Subcommittee Meeting, Monterey, Nov. 1993, V. II, p. 87). However, reducing the delay time of self-ignition increases the risk of premature self-ignition of the fuel and its ignition from a hot surface.

The third method is based on the use of several (two or more) fuel compositions with different detonation abilities (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), p. 624; Georg E., Marge P., Sabel'nikov VA, Self-ignition in supersonic flows: hydrogen versus hydrocarbons-hydrogen mixtures - chemistry / mixing interplay. In: Pulse and Continuous Detonations / GD Roy, SM Frolov, JO Sinibaldi, Eds., Moscow: Torus Press, 2006; Frolov SM, Basevich V. Ya., Belyaev AA, Neuhaus MG Application of fuel blends for controlling detonability in pulsed detonation engines. In: Gaseous and Heterogeneous Detonations: Science to Applications / GD Roy, SM Frolov, K. Kailasanath, NN Smirnov, Eds., Moscow, ENAS Publishers, 1999, pp. 313-330; patent RU 2371469 C2, CI OL 1/04, CIOL 1/06, CIOL 1/23 (2006.01), 01/15/2007). In this case, detonation is initiated in the region occupied by the fuel composition of greater detonation ability, and is transferred to the region occupied by the combustible mixture with regular liquid hydrocarbon fuel. It is proposed to use hydrogen, ethylene, acetylene as combustible components with high detonation ability. (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), p. 624; Kuznetsov M., Alekseev V., Matsukov I. Detonation transmission from one mixture to another of low sensitivity. In: Advances in Confined Detonations / GD Roy, SM Frolov, R. Santoro, and SA Tsyganov Eds., Torus-Press, Moscow, 2002, 312 p.) Instead of using It is proposed to use either ordinary oxygen (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 instead of air in the field of detonation initiation instead of air) (2004), p. 624), or oxygen in electron Excited state (AM Starik, NS Titiva, Low-temperature initiation of the detonation combustion of gas mixture in a supersonic flow under excitation of the 0 ₂ ('Δ _§ ) state of molecular oxygen / Dokl.Phys. 46: 627: 32; AM Starik, NS Titiva, Sharipov AS / in: Detonation and detonative combustion // Ed. by G. Roy, S. Frolov. Moscow: Torus Press, 2010, 520 p). The disadvantage of this method is that the transfer of detonation from one combustible mixture to another is a complex dynamic phenomenon, determined by the characteristics of the transition layer and, therefore, to reliably initiate detonation of a regular liquid hydrocarbon fuel in an air mixture, special measures must be taken to ensure the required stratification of the combustible mixture .

The closest in technical essence to the proposed method for increasing the detonation ability of liquid hydrocarbon fuel is a method for separate or joint distributed supply of liquid hydrocarbon fuel (simulated by iso-octane) and a liquid aqueous solution of hydrogen peroxide into the combustion chamber of a burner device or engine operating on controlled detonation, discussed in articles (SM Frolov, V.Ya. Basevich, A.A. Vasil'ev / Dual-fuel concept for advanced propulsion. In: High-Speed Deflagration and Detonation: Fundamentals and Control. In: Roy G, Frolov S, Netzer D, Borisov A, Eds., High-speed deflagration and detonation: fundamentals and control. Moscow: Elex-KM Publ; 2001. p. 315-322; Frolov SM, Posvianskii VS, Basevich V. Ya., Belyaev AA, Kuznetsov NM On application of emulsified liquid fuels for combustion control. In: Combustion and Noise Control. Ed. By GD Roy, Cranfield, UK, Cranfield Univ. Press, 2003, pp. 257-263) and (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), pp. 645-646) (prototype). In (GD Roy, SM Frolov, AA Borisov, DW Netzer / Pulse detonation propulsion: challenges, current status, and future perspective. Progress in Energy and Combustion Science 30 (2004), pp. 645-646) based on thermodynamic calculations and calculations of evaporation and self-ignition of droplets of liquid hydrocarbon fuel in an atmosphere of air, water vapor and hydrogen peroxide vapor, it is shown that a separate or combined (in the form of an emulsion of the type “droplets of concentrated hydrogen peroxide in liquid hydrocarbon fuel” type) is a distributed supply of liquid hydrocarbon fuel and an 85 percent peroxide hydrogen (volume concentration I 20%) in the combustion chamber allows to reduce the energy 1500 times detonation initiation compared to pure air mixture of the liquid hydrocarbon fuel.

The prototype method is simple to implement and affordable, but does not solve the problem of preventing premature self-ignition of a multicomponent mixture or its ignition from a hot surface at temperatures up to 600-800 K. It should be emphasized that hydrogen peroxide is a substance that decomposes exothermically quickly at elevated temperatures and in contact with traditional structural materials (alloy steel and others).

Disclosure of invention

The objective of the invention is to provide such a method of increasing the detonation ability of liquid hydrocarbon fuel, in which liquid hydrocarbon fuel is supplied to the combustion chamber without any preliminary thermal preparation outside the combustion chamber and the premature self-ignition of the combustible mixture and its ignition from a hot surface at temperatures up to 600 are guaranteed -800 K.

The solution to this problem is achieved by the proposed method of supplying liquid hydrocarbon fuel to the combustion chamber of a burner device or engine operating on controlled detonation, including a separate or joint distributed supply of liquid hydrocarbon fuel and additional fuel to the combustion chamber, in which gaseous hydrogen is used as additional fuel, and the combustion chamber, provides on average a uniform spatial distribution of droplets of liquid hydrocarbon fuel, as well as hydrogen and air concentrations in the region of initiation and propagation of detonation, and the minimum concentration of hydrogen in the region of initiation and propagation of detonation should be higher than 4% (vol.), provided that the degree of preliminary evaporation of liquid hydrocarbon fuel inside the combustion chamber before the detonation wave arrives does not exceed 20-25%, and higher than 3% (vol.), provided that the degree of pre th evaporating liquid hydrocarbon fuel within the combustion chamber prior to the arrival of the detonation wave is greater than 25%.

Brief Description of the Drawings

In FIG. 1a schematically shows examples of the organization of a separate supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a pulse-detonation combustion chamber.

In FIG. 16 schematically shows examples of the organization of a separate supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a continuous detonation combustion chamber.

In FIG. 2a schematically shows examples of the organization of a joint supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a pulse-detonation combustion chamber.

In FIG. 26 schematically shows examples of the organization of a joint supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a continuously detonation (Fig. 26) combustion chamber.

In FIG. Figure 3 shows the calculated dependences of the maximum temperature in the gas phase _{g> ma} x on time t for stoichiometric triple hybrid n-heptane (droplets) -hydrogen-air mixtures with different hydrogen contents: 0% (vol.), 7.5% (vol. ) and 14.75% (vol.).

In FIG. Figure 4a presents a comparison of the dependences of the maximum gas temperature on time in ternary hybrid mixtures of n-heptane without hydrogen (dashed curves) and with the addition of hydrogen of 7.5% (vol.) At different initial temperatures.

In FIG. Figure 46 presents a comparison of the dependences of the maximum gas temperature on time in ternary hybrid mixtures of n-decane without hydrogen (dashed curves) and with the addition of 7.5% hydrogen (vol.) At different initial temperatures In FIG. Figure 5 shows the calculated dependences of the maximum gas temperature T _{g max} and the square of the diameter of an n-heptane drop d ² versus time in a stoichiometric n-heptane-air mixture (fuel excess coefficient Ф = 1) at ψ = О (do = 10 μm), 0, 25 (O ~ 9 MKM), 0.50 (δ? ~ 8 μm) and 0.75 (do - 6 μm) without hydrogen additives.

In FIG. Figure 6 shows the curves of the maximum gas temperature around a drop of n-heptane and the square of the diameter of the drop versus time for a droplet mixture with 4.3% (vol.) Н ₂ and ψ = 0 (curves 3) and for droplet mixtures without the addition of Н ₂ , but with ψ = 0.50 and 0.25 (curves 1 and 2).

An embodiment of the invention

Liquid hydrocarbon fuel and hydrogen can enter the combustion chamber separately in the form of distributed jets or together in the form of a heterogeneous fuel mixture formed by sparging the fuel with hydrogen. In FIG. 1 schematically shows examples of the organization of a separate supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a pulse detonation (Fig. 1a) and continuous detonation (Fig. 16) combustion chambers. In FIG. Figure 2 shows schematically examples of the organization of a joint supply of liquid hydrocarbon fuel (T) and hydrogen (B), as well as air (O) in a pulse detonation (Fig. 2a) and continuous detonation (Fig. 26) combustion chambers.

The claimed invention was developed on the basis of detailed theoretical studies of the effect of hydrogen on the self-ignition and detonation of droplet mixtures of hydrocarbon fuels with air, performed using numerical simulation.

The self-ignition calculations of triple homogeneous and heterogeneous (drop) hydrocarbon-hydrogen-air mixtures were performed for four individual hydrocarbons: n-heptane, n-decane, n-dodecane and n-tetradecane, often used to model real motor fuels: gasoline, kerosene and diesel fuel. The calculations were carried out using comprehensively tested computational programs that make it possible to predict with sufficient accuracy the physicochemical characteristics of multicomponent homogeneous and heterogeneous (droplet) combustible mixtures, including self-ignition delays, the propagation velocity and structure of the laminar flame, the propagation velocity and structure of detonation, as well as the propagation limits flame and detonation based on detailed kinetic mechanisms of chemical reactions and an extensive database of all thermophysical data for hydrocarbon fuels and their derivatives. The calculations used the proven detailed kinetic mechanism of the oxidation of n-tetradecane containing, as components, the oxidation mechanisms of n-dodecane, n-decane, n-heptane and hydrogen. A description of the calculation methods is given in (Frolov SM, Medvedev SN, Basevich V. Ya., Frolov FS Self-ignition of hydrocarbon-hydrogen-air mixtures. International Journal of Hydrogen Energy, 2013, Vol. 38, pp. 4177-4184; Basevich V. Ya., Belyaev AA, Medvedev SN, Posvyanskii VS, Frolov FS, and Frolov SM Simulation of the autoignition and combustion of n-heptane droplets using a detailed kinetic mechanism. Russian Journal of Physical Chemistry B, 2010, Vol. 4 , No. 6, pp. 995-1004; Basevich V. Ya., Belyaev A.A., Posvyanskiy V.S., Frolov S.M. Mechanisms of oxidation and combustion of normal paraffin hydrocarbons: transition from C1-C10 to C1 1 -C16. Chemical Physics, 2013, Volume 32, N ° 4, pp. 1-10).

It turned out that the addition of hydrogen to both a homogeneous and a heterogeneous hydrocarbon-air mixture at a temperature of ₀ <1050 K increases the total delay of self-ignition, i.e. at such temperatures, hydrogen plays the role of an autoignition inhibitor. Conversely, the addition of hydrogen to a homogeneous or heterogeneous hydrocarbon-air mixture at To> 1050 reduces the total delay of self-ignition, i.e. at such temperatures, hydrogen plays the role of a self-ignition promoter.

Calculations of the effect of hydrogen additives on the detonation ability of a homogeneous and heterogeneous (droplet) combustible mixture showed that small hydrogen additives in such mixtures have a significant effect on the detonation ability of a fuel. It is proved that when more than 4% (vol.) H _{2 is} added, the droplet hydrocarbon-air mixture becomes detonative even without preliminary evaporation of the fuel.

Thus, the fundamental difference between this invention and the prototype is the fact that the addition of hydrogen leads to the inhibition (and not promotion, as in the case of the addition of hydrogen peroxide) self-ignition at temperatures up to 1050 K and a significant increase in detonation ability at temperatures above 1050 K and pressures characteristic for shock waves leading to detonation. To illustrate the invention, we give examples of calculations.

Example 1. Self-ignition of drip mixtures of liquid hydrocarbon fuels in air without additives and with hydrogen additives.

In FIG. Figure 3 shows the calculated dependences of the maximum temperature in the gas phase _ta on time t for stoichiometric triple hybrid n-heptane (droplets) -hydrogen-air mixtures with different hydrogen contents: 0% (vol.), 7.5% (vol.) and 14.75% (vol.). The calculations were performed for droplets with an initial diameter of do = 60 μm at an initial temperature of o = 1000 K and a pressure of Po = 2 MPa. An analysis of the spatial distributions of the intermediate reaction products showed that a stepwise change in the maximum gas temperature in FIG. 3 is associated with the local appearance of a blue flame due to the decomposition of hydrogen peroxide formed as a result of oxidation of hydrocarbon fuel. With an increase in the hydrogen content in the triple hybrid mixture, the blue flame zone degenerates, and the total self-ignition delay increases.

The reason for the increase in the delay of self-ignition is that the interaction of active radicals formed through the channel of n-heptane oxidation with hydrogen and intermediate products of its oxidation leads to the formation of less active particles (for example, Н0 ₂ ) and, therefore, inhibition of the reaction. In other words, hydrogen and products formed along the hydrogen oxidation channel affect the processes of accumulation and decomposition of hydrogen peroxide, which determine the development of the blue flame stage of n-heptane. These considerations are confirmed by the calculation results shown in FIG. 4. Here is a comparison of the dependences of the maximum gas temperature on time in ternary hybrid mixtures of n-heptane (Fig. 4a) and n-decane (Fig. 46) without hydrogen (dashed curves) and with the addition of hydrogen 7.5% (vol.) at different initial temperatures. It is clearly seen that hydrogen additives affect not only the total delay of self-ignition, but also the duration of the intermediate stages of the multi-stage process of self-ignition of droplets. At relatively low initial temperatures (for example, at To = 800 K), a significant increase in the duration of the zones of cold and blue flame is observed. This indicates the selection by hydrogen of intermediate active radicals participating in the corresponding channels of nucleation and branching of chains. However, for To <1050 K, the self-ignition triple delay the droplet mixture increases with the addition of hydrogen, and at ₀ > 1050 K it decreases.

Example 2. Detonation of droplet mixtures of liquid hydrocarbon fuels in air without additives and with hydrogen additives.

It was believed that the detonation shock wave propagates through a mixture of hydrocarbon fuel with air, in which the fuel is partially in the liquid state in the form of a homogeneous monodisperse gas suspension of droplets with a diameter of do, and partially in the vapor state, at a speed of 1800 m / s, and the temperature and the pressure behind the shock wave takes the values r _g0 = 1500 K and P = 3 MPa. The content of fuel vapor in the gas phase was set by the degree of preliminary evaporation of droplets ψ. It was assumed that in the absence of preliminary evaporation of fuel, i.e. at ψ = 0, the droplets had a diameter of do = 10 μm. The well-known criterion (Basevich V. Ya., Frolov S. M, Posvyanskiy V. S. Conditions for the existence of stationary heterogeneous detonation // Chemical Physics. 2005. V. 24. N "7. P. 58 -68): the mixture is considered to be detonative if the time of complete combustion of the mixture behind the shock wave t * does not exceed 100 μs. Calculations were performed both in the absence and in the presence of hydrogen additives.

In FIG. Figure 5 shows the calculated dependences of the maximum gas temperature T _{& max} and the square of the diameter of an n-heptane drop d ² versus time in a stoichiometric n-heptane-air mixture (fuel excess coefficient Ф = 1) at ψ = 0 (i / fl - 10 μm), 0 , 25 (do - 9 microns), 0.50 (/ o ~ 8 microns) and 0.75 (do - 6 microns) without hydrogen. It is seen that for ψ = 0, i.e. Without partial preliminary evaporation (before the arrival of the shock wave), n-heptane droplets with <^ = 10 μm in a gas suspension of stoichiometric composition do not have time to completely burn out in a time f * = 100 μs. According to the accepted criterion, at ψ = 0, detonation is impossible. In other cases, i.e. at ψ = 0.25, 0.5, and 0.75, vapor-droplet mixtures of n-heptane with air are capable of supporting detonation.

The results are confirmed by experimental studies (see, for example, (Brophy S.M., Netzer DW et al. Detonation of a JP-10 aerosol for pulse detonation applications. In: High-Speed Deflagration and Detonation / GDRoy, SM Frolov, D .Netzer, AA Borisov, ^' Eds., ELEX-KM Publishers, Moscow, 2001, 384 p; Frolov S. M., Aksenov V. S. The transition of combustion to detonation into kerosene air mixture // Reports of the Academy of Sciences. - 2007. - T. 416. - N ° 3. - S. 261-264.). In these studies, detonation of atomized kerosene JP-10 (Brophy et al) and TC-1 (Frolov et al) in air was possible only with partial evaporation of fuel (up to ψ = 0.75).

Then investigated the effect of H ₂ additives on the detonation ability of a droplet gas suspension. It turned out that even small additions of H ₂ to the drip n-heptano-air and n-decano-air mixture give a significant effect on the detonation ability of the fuel. So, with the addition of 4.3% (vol.) H _{2 the} droplet gas suspension is already able to detonate without first evaporating the fuel. In support of this conclusion in FIG. Figure 6 shows the curves of the maximum gas temperature around a drop of n-heptane and the square of the diameter of the drop versus time for a droplet mixture with 4.3% (vol.) Н ₂ and ψ = 0 (curves 3) and for droplet mixtures without the addition of Н ₂ , but with ψ = 0.50 and 0.25 (curves 1 and 2). In other words, to increase the detonation ability of atomized liquid fuel, small additions of hydrogen are as effective as 25% -50% pre-evaporation of fuel.

Thus, a method is proposed for increasing the detonation ability of liquid hydrocarbon fuel, in which liquid hydrocarbon fuel is supplied to the combustion chamber without any preliminary thermal preparation outside the combustion chamber and the premature self-ignition of the combustible mixture and its ignition from a hot surface at temperatures up to 600- 800 K.

Claims

Claim

Item 1. A method of supplying liquid hydrocarbon fuel to the combustion chamber of a burner device or engine operating on controlled detonation, comprising a separate or joint distributed supply of liquid hydrocarbon fuel and additional fuel to the combustion chamber, characterized in that to increase the detonation ability of the multicomponent air-fuel mixture and to prevent self-ignition or ignition of the mixture from a hot surface at temperatures up to 600-800 K as an additional fuel hydrogen gas is used.

Paragraph 2. The method according to claim 1, characterized in that the supply of hydrocarbon fuel and hydrogen gas is arranged so that in the combustion chamber, on average, a uniform spatial distribution of droplets of liquid hydrocarbon fuel is formed, as well as hydrogen and air concentrations in the region of initiation and propagation of detonation, moreover, the minimum concentration of hydrogen in the region of initiation and propagation of detonation should be higher than 4% (vol.), provided that the degree of preliminary evaporation of liquid hydrocarbon fuel inside the combustion chamber before the arrival of the detonation wave does not exceed 20-25%, and higher than 3% (vol.), provided that the degree of preliminary evaporation of liquid hydrocarbon fuel inside the combustion chamber before the arrival of the detonation wave exceeds 25%.