RU2655025C2 - Burner for thermal units of field installations - Google Patents

Abstract

FIELD: power industry.

SUBSTANCE: burner for thermal units of field installations comprises a fuel sprayer - a nozzle with an electrode, a low-power high electric voltage source and a dielectric tube. The electrode with the dielectric tube is made in the form of a hitch attachment fixed at the burner through insulator with high voltage electrode of L-shaped type. Dimensions and distance of the high voltage electrode tip from the grounded burner may vary depending on its structure and capacity. Bare end of the high-voltage electrode is located in the zone of burner flameignition initiation at a distance less than the rest part of the electrode, so that silent discharge would occur only at the tip area.

EFFECT: increased efficiency of combustion processes.

4 dwg

Description

The invention relates to a power system, in particular, to devices for burning liquid fuel, mainly by evaporative nozzles, and can be used on field means for preparing and transporting food and on other thermal devices in order to increase their efficiency.

All known manufactured burners FK-01, FK-02, KGF-2, KGF-3M, KGF-4M (Operation of technical means of cooking and transporting food in the field. M .: VI, 1980) [1], including including multi-fuel ones, due to the insufficient quality of mixture formation, they need to supply an excess amount of air, thereby spending part of the combustion energy on its heating and significantly reducing the temperature of the flame and flue gases. The disadvantages include the fact that, due to incomplete combustion of fuel, they smoke heavily and unmask a military object, emit a significant amount of carbon monoxide, soot and other harmful volatile substances. The use of injection, swirling flows, artificial blasting and even the introduction of a pure oxidizing agent (oxygen) do not solve the problem of complete burning of fuel. This is due to the cluster nature of the structure of the injected fuel and air. It is known that the fuel combustion (oxidation) reaction begins on the contact surface of fuel clusters with oxidizer clusters and moves relatively slowly towards the center of the clusters. Theoretically, simultaneous oxidation of fuel molecules in the entire volume is required. Currently, the problem of the destruction of clusters to molecular structures is partially solved by the use of high-voltage electric fields (patents No. 2125682, 2160414, 2079786, EA 005632, as well as the RF patent for utility model No. 71732) [2, 3, 4]. In this case, the Coulomb forces with the speed of propagation of the electromagnetic wave crush and mix the combustible mixture into smaller clusters and even molecules.

Thus, various methods are known to increase the efficiency of combustion processes, for example, by ionizing an oxidizing agent (air) involved in the combustion process. In patent EA 005632 [5] it is proposed to ionize it before passing the oxidizing agent into the combustion zone by passing it through an electrode grid with a voltage of 30,000 W, equipped with electric charge expanders. The use of the device according to this patent makes it possible to reduce fuel costs by an average of 0.5-1.5%, increase the efficiency of thermal units by 0.5-3%.

The solutions used in these patents make it possible to increase the efficiency of combustion processes, reduce fuel costs, and increase the efficiency of fuel and energy installations. However, in all these patents, very complex electrode designs are proposed that require expensive, heat-resistant and oxidation-resistant metals and manufacturing techniques, there are no instructions on the specific placement of electrodes in the furnace volume, and there are no references to scientific studies of these devices. Such designs are difficult to technically implement and use in the field. In this case, in most cases, the electric field was treated either separately with an oxidizing agent (air ionization), or with a torch (flame) itself, where temperature ionization is already deeply developed, and the electrode quickly burns out. Such a formulation of the problem complicates devices for intensifying flame combustion and requires increased voltages of a high-voltage source (30 kV or more). Given that the electric field in the combustible mixture propagates after creating a quiet discharge according to the “domino” principle (like a spark, ignites any amount of fuel) and for burners of different power it practically does not depend on the amount of fuel burned, but only on the type of fuel (to a small extent ), we propose a universal hinged device with the feature that the tip of the electrode is placed in a cold region before the start of the flame front along the longitudinal axis of the torch, where the mixture formation is completed, but the cluster system of pairs s and gases are not destroyed. In this case, the Coulomb forces of the electric field most effectively mix and act on the combustible mixture, which is expressed when burning by increasing the flame temperature by 120-200 ° C and the efficiency of the heat block by 5-6%.

The burner according to the patent of the Russian Federation for utility model No. 71732 [5], as the closest to the proposed combination of essential features, is selected as a prototype.

It includes an electrostatic fuel atomizer containing an additional electrode in contact with the fuel stream immediately after the nozzle nozzle (without indicating its location), and a low-power source of high voltage with an electrical connection of its output voltage with one electric potential to the burner body and a second electric potential connected to this additional electrode, located behind the nozzle of the fuel burner, at a distance from it sufficient to prevent breakdown from this electrode to its housing, and this additional electrode may be made of a metal ring placed on the end of the hollow dielectric tube, worn tightly on the nozzle from the outside, with an inner diameter of the metal ring equal to the inner diameter of the nozzle of the fuel burner, wherein said additional electrode The electrostatic burner fuel atomizer can be structurally made in the form of a vortex nozzle with a cavity inside and with inclined outlet openings in it and several t ngentsialnymi nozzles for feeding into this cavity and the vortex mixing electrostatically atomized fuel and additional air-fuel mixture - the ionized air, water and part of the exhaust gases in a secondary combustion products.

The disadvantages of the burner are the experimentally unreasonable distance of the electrode from the grounded nozzle, its significant complication due to the supply of separately ionized air, water and part of the exhaust gases in the form of secondary combustion products, too high a voltage close to the breakdown voltage is allowed. This requires an increase of 3-4 times the power of a high-voltage device and high-quality insulators.

An object of the invention is to increase the efficiency of combustion processes occurring in them, with relatively simple devices for intensifying combustion and at lower voltages.

The technical task is due to the fact that the burner for the thermal units of field installations containing a fuel atomizer (nozzle) with an electrode, a low-power source of high electric voltage and a dielectric tube, differs in that the electrode with a dielectric tube is made in the form of a mounted device mounted on the burner through an insulator with a high-voltage electrode of the L-shaped type, and the dimensions and distance of the tip of the high-voltage electrode from the grounded burner can vary depending on its design and power and, while the bare end of the high voltage electrode is in the initiation area ignition burner flame at a distance smaller than the rest of the electrode to silent discharge occurs only in the vicinity of the tip.

The technical result of the invention is to increase the efficiency of the burner due to the installation of a universal hinged device, which improves the performance of the thermal unit with the ensuing consequences of changes in thermal performance and environmental friendliness, reduces the metal consumption and dimensions of the flues, reduces the amount of flue gases by 20-25%, and water heating at the same diesel fuel consumption will increase by 5-6% (Amosova, M. A. Development of a method for intensifying the heating of the working surface of thermal of food industry apparatus: abstract of the dissertation ... Candidate of technical sciences: 05.18.12. / Amosova Marina Andreevna [Place of protection: St. Petersburg State University of Low Temperature and Food Technologies] - St. Petersburg, 2010. - 15 p.) [6].

The essence of the proposed technical solution is illustrated by drawings, diagrams and graphs shown in FIG. 1-4.

In FIG. 1 shows a circuit diagram of a universal attachment.

In FIG. 2 shows a burner with a universal attachment mounted on it, on which is indicated: pos. 1 - insulator; pos. 2 - nozzle; pos. 3 - electrode; pos. 4 - tube-insulator; pos. 5 - holder clamp; pos. 6 - terminal; pos. 7 - a source of high voltage; pos. 8 - ground terminal.

The burner for thermal units of field installations contains a burner nozzle with a universal hinged device mounted on it, consisting of an insulator (1) (as an option, a porcelain ring made of refractory ceramic), which is attached to the nozzle body with a ground terminal (8). A high voltage electrode (3) is fixed in the insulator (1) with the possibility of longitudinal movement along the thread in it. The electrode (3) is covered with an insulating tube (4) (ceramic, as an option) and is fed through a screw terminal (6) from a high-voltage source (7) (as an option, with protective resistance). The electrode (3) is made of 5-6 mm heat-resistant wire and, to enhance ion formation at a given point, has an end pointed at an angle of 90 °. Power consumption N = 0.02-0.03 kW. The output current I out = 0.001-0.003 A is limited by the resistance R = from 100 kOhm to 1 mOhm with a power of 5-10 W for short circuit protection and for personnel safety. Transformer and voltage multiplier - from previously commercially available portable TVs, designed for 12 W battery power.

The output voltage Uout = 700-10000 V, plus - to the mass of the burner, minus - to the electrode terminal (Patent EA No. 005632 "Device for preparing an oxidizer for fuel combustion", Gromtsev SA, Smirnov VT, Purmal M. I. A method of regulating the combustion process and a device for its implementation. Description of the invention. VNIIGPE, AS No. 1394000, 1986) [7, 8].

The principle of operation of the burner: from the car’s generator or battery, the direct current is converted into alternating current supplied to the step-up transformer and rectifier without smoothing the ripples, from where it is supplied to the high-voltage electrode. Moreover, the voltage of the high-voltage source U is determined by the formula

,

,

where U CR - breakdown voltage for a vaporous or drip-sprayed fuel mixture of 22-27 kV / cm; b is the distance of the electrode from the nozzle of the burner, cm; U - voltage of a high-voltage source, V., necessary for creating a quiet discharge.

It is known that even a small amount of ionized fuel mixture (for example, 0.00001% of the total second flow rate) is sufficient for the manifestation of the "domino" effect, that is, ionization of the entire volume of the torch. Given that the propagation velocity of the ionization of flare clusters is close to the speed of light and practically does not depend on the power of the high-voltage source (after reaching the threshold ionization energy of the mixture) (Stepanov EM, Dyachkov BG Ionization in a flame and electric field. - M. : Metallurgy, 1968 - 310 s .; Lauton J., Weinberg F. Electric aspects of combustion. - M.: Energia, 1976. - 296 s .; Dudyshev VD “New electric fire technology - an effective method for solving environmental and energy problems ”//“ Ecology and Industry of Russia ”, No. 3, 1997) [9, 10, 11].

The experiments showed that the use of the proposed burner increases the efficiency of the thermal blocks due to the fact that at the exit of the burner in the ignition start region the fuel mixture is ionized under the influence of a pulsed electric field (from a direct current not smoothed by capacitors or inductances). In this case, instantly, with the speed of propagation of the electromagnetic wave, the Coulomb repulsive forces begin to act in the entire volume of the ionized combustible mixture, intensively mixing the combustible mixture. The need for excess air, as shown by experiments, is reduced to α = 1.0-1.05 while providing smokeless combustion. This leads to the simultaneous burning of the torch in its entirety at an elevated temperature and the multiple intensification of radiation in the visible and ultraviolet regions. The heating of the working surface of the digestion boilers is already taking place not only by convective means due to hotter gases, but to a greater extent by radiation of the torch. The amount of carbon monoxide and unburned carbon particles with a good mixing of the mixture decreases, as does the frequency of cleaning the outer surface of the boilers from soot.

Held at the Spetstekhmash plant in Vsevolozhsk, Leningrad Region in November-December 2015, the experiment gave positive results. The proposed universal attachment device can be used for any burner, changing only the voltage on the electrode due to the need to install an uninsulated tip of the electrode at the beginning of the ignition front of the combustible mixture. This clearance from the nozzle of the nozzle to the front of ignition depends on the power of the burner and the pressure of the jet at the outlet. The electrical circuit of such a device currently allows smooth adjustments even in automatic mode, depending on the quality and type of fuel. A 20% reduction in the amount of flue gas due to a decrease in the required coefficient of excess air from 1.25 to 1.05 reduces the amount of cold air that must be preheated during combustion. In general, with the same operating time of the field kitchen, the temperature of heating the water at the same diesel consumption will increase by 5-6% due to more complete burning of carbon monoxide and soot (the effect of smokelessness and an increase in the temperature of combustion products in the furnace). It was experimentally confirmed that in this case the effect of electrothermal intensification of heat transfer is observed. The ions of the burnt mixture charged from the electrode are intensively attracted to the nearest grounded surfaces (the bottom of the boiler), lose their charge and give way to new masses of charged gases. Thus, due to the effect of electroconvection, charged combustible gases are turbulized and intensively perform the function of a heat carrier, excluding stagnant zones at the outer surface of the boiler.

In FIG. Figure 3 shows the experimental data on the change in the amount (carbon monoxide) of carbon monoxide from the tension on the burner electrode in the smoke of the field kitchen KP-130.

In FIG. 4 shows a graph of the temperature change in the boiler of 1 dish depending on the voltage on the electrode (after 30 minutes). At a temperature of 70-75 ° C, intense denaturation of proteins and gelatinization of starch begins, which can be considered the beginning of cooking.

Thus, the proposed constructive solution of the hinged device does not require such a high voltage as with conventional (bulk) ionization of air, or additional flame ionization. It can be seen from the graphs that a further increase in the operating voltage at the electrode is inefficient, since already at 8 kV / cm the entire volume of the mixture is ionized and enters into a chemical combustion reaction.

At the same time, the effect of not only increasing the brightness of the flame, but also the electrothermal effect, that is, the destruction of the boundary layer near the walls of the digestion boiler by charged particles of flue gases, was experimentally discovered, as a result of which the heat transfer coefficient increased by 8-12%.

Bibliography

1. Operation of technical means of cooking and transporting food in the field. M .: VI, 1980

2. RF patent for the invention No. 2125682 "Method of intensification and control of the flame."

3. RF patent for the invention No. 2160414 "Method of burning fuel and a device for this implementation."

4. RF patent for the invention No. 2079786 "Method for intensifying the combustion of a flame in a furnace of a boiler plant."

5. RF patent for utility model No. 71732 "Electrostatic fuel injector."

6. Amosova, M. A. Development of a method for intensifying the heating of the working surface of thermal apparatuses of the food industry: abstract of the dissertation ... candidate of technical sciences: 05.18.12. / Amosova Marina Andreevna [Place of protection: St. Petersburg. state un-t low temperatures. and food technology]. - St. Petersburg, 2010 .-- 15 p.

7. Patent EA No. 005632 "Device for the preparation of an oxidizing agent for fuel combustion."

8. Gromtsev S.A., Smirnov V.T., Purmal M.Ya. A method of regulating the combustion process and a device for its implementation. Description of the invention. VNIIGPE, A.S. No. 1394000, 1986

9. Stepanov E.M., Dyachkov B.G. Ionization in flame and electric field. - M.: Metallurgy, 1968 - 310 s.

10. Lauton J., Weinberg F. Electric aspects of combustion. - M .: Energy, 1976 .-- 296 p.

11. Dudyshev V.D. “New electric fire technology - an effective method for solving environmental and energy problems” // Ecology and Industry of Russia, No. 3, 1997

Claims (1)

A burner for thermal units of field installations containing a fuel atomizer - a nozzle with an electrode, a low-power source of high voltage and a dielectric tube, characterized in that the electrode with a dielectric tube is made in the form of a hinged device mounted on the burner through an insulator with a high-voltage electrode of the L-shaped type moreover, the size and distance of the tip of the high-voltage electrode from the grounded burner may vary depending on its design and power, while the uninsulated end The high-voltage electrode is in the initiation area ignition burner flame at a distance smaller than the rest of the electrode to silent discharge occurs only in the vicinity of the tip.

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