RU203266U1 - AIR STARTING SYSTEM FOR MILITARY ENGINE WITH INDUCTION HEATER - Google Patents

Abstract

The utility model relates to the field of transport engine building, namely to air start systems for engines of mobile vehicles, and can be used to increase the efficiency of launching samples of military equipment of the Ground Forces of the Russian Federation. it into the engine cylinders and the elimination of unproductive air flow from the air start system. The technical result is achieved by installing a heat-insulated metal case, inside it there is an induction device, the winding of which is evenly placed on the surface of the dielectric tube.

Description

The proposal relates to the field of transport engine building, namely, to air start systems for engines of mobile vehicles, and can be used to increase the efficiency of launching samples of military equipment of the Ground Forces of the Russian Federation.

Known system of air start of the engine (Airborne combat vehicles BMD-1P and BMD-ShK. Technical description. - Moscow: Military Publishing House, 2002 - 384 S.) containing a cylinder, valve, pressure gauge, union for connecting consumers, reducer, electric air valves, tees , flow cylinder, compressor, pressure switch, moisture-oil separator, shut-off valve, compressor, felt air filter, pressure reducers.

Also known, fundamentally similar to the above, the air launch system of the BMP-2 infantry fighting vehicle (BMP-2 infantry fighting vehicle. Technical description and operating instructions. Part PM, Military publishing house, 2001, 319 s), containing an electric pneumatic valve, sump, check valve, air distributor, start valve, junction box, cylinder, compressor, felt air filter, pressure reducers.

A common disadvantage of these designs is the following. The air intended for starting the engine on board the vehicle is stored at sufficiently high pressures, reaching 20.0 MPa. At the same time, the compressed air pressure required to start a piston engine is usually in the range from 3.0 to 7.0 MPa. To achieve such an operating pressure in the air start systems of a diesel engine of mobile machines, air is throttled in the gearboxes to a predetermined level, regardless of the initial value. However, as you know, as a result of the Joule-Thompson effect in the gas reducer, not only the air pressure decreases, but also its temperature. When the starting temperature is lowered, for example, in winter operating conditions of the machine, this cooling effect increases. So, for example, in the case of throttling from 20.0 to 5.0 MPa at an initial temperature of minus 20 ° C, the air is cooled by about 20-15 degrees as a result of the Joule-Thomson effect. In this case, the final starting air temperature will reach minus 40-45 ° С.

The low temperature of the starting air entering the engine cylinders has a negative effect on a number of its characteristics, namely

firstly, the efficiency of starting the diesel engine decreases. This is primarily due to the overcooling of the cylinder walls and combustion chambers when the compressed air introduced into them expands. When starting a cold engine, more heat will be taken from the air compressed in the cylinders; as a result, the temperature and pressure in the cylinder precooled with starting air may be low and insufficient for spontaneous ignition of the injected fuel;

secondly, the durability of the engine decreases due to an increase in the thermal stress of the engine parts forming the combustion chamber. It is known that thermal stress means not only the absolute temperature on the surface of the walls of the cylinder-piston group (CPG), but also temperature stresses due to temperature unevenness at different points of the parts forming the combustion chamber. With frequent changes in the temperature regime of the CPG associated with frequent air starts of a hot engine (especially in conditions of negative ambient temperatures), the phenomenon of "thermal fatigue" occurs in engines with high thermal load. Thermal fatigue is determined by the accumulation of heat cycle cycles and thermal stresses. This phenomenon can be schematically represented as follows: at a high temperature of the CPG parts, plastic deformation in the surface layer is possible due to compressive stresses; upon subsequent rapid cooling of the wall (when interacting with the cooled compressed air of the air launch system), tensile forces appear in this layer (the material does not have time to "get rid" of plastic deformation), which, when the ultimate strength is exceeded, lead to surface cracks.

The above circumstances convincingly indicate the need to ensure heating of the compressed air of the air start system before it enters the engine cylinders, especially in conditions of negative and extremely negative ambient temperatures.

The closest in technical essence and the achieved technical result is an engine air start system with a vortex heater (patent RU 196360, Publ. 02.26.2020, bull. No. 6), containing a central flap electrically connected to an electro-pneumatic valve, a high-pressure cylinder pneumatically connected to a felt air filter, a pressure reducer, a sump, an air distributor, a start valve, a junction box, a vortex tube, its own cold flow diffuser connected to an electro-pneumatic valve, which is controlled from the central panel.

The disadvantage of this system is its low efficiency, due to insufficient heating of the compressed air of the air start system of the engine, associated with the low efficiency of the vortex tube, especially when it operates with hydraulic resistance at the outlet of the hot stream. It should also be noted that the unproductive air consumption from the air launch system is associated with the fact that part of the compressed air from this system is discharged into the atmosphere through the diffuser of the cold flow of the vortex tube, without performing useful work.

The technical result of the claimed system is to provide high-temperature heating of the compressed air of the air start system before it enters the engine cylinders and the elimination of unproductive air consumption from the air start system.

The technical result is achieved by installing a heat-insulated metal case, inside it there is an induction device, the winding of which is evenly placed on the surface of the dielectric tube.

The proposal is illustrated by drawings, where:

in fig. 1 shows a schematic diagram of an air start system for a military vehicle engine with an induction heater;

in fig. 2 induction heater in cross section.

The proposed air start system for an engine of military equipment with an induction heater contains a cylinder 1 with compressed air by high pressure pipelines, connected to a junction box 2, a felt air filter 3 and two pressure reducers 4, an electro-pneumatic valve 5, a sump 6, a central shield 7, electrically connected to the winding 8 of an induction device, evenly located on the surface of a dielectric tube 9, a heat-insulated metal body 10, an air distributor 11 and a start valve 12.

The proposed system of air start of a military vehicle engine with an induction heater operates as follows.

The system operates in two modes. The first mode is used mainly in conditions of negative or extremely negative ambient temperatures, when heating of the compressed air of the engine air start system is required. In this case, starting the engine with compressed air is carried out by pressing the buttons "heating the starting air" and "start" (not shown in the figure) on the central panel 7, while the electro-pneumatic valve 5 and compressed air from the cylinder 1 through high pressure pipelines, bypassing the junction box 2 and the felt air filter 3 enters the gearboxes 4, in which the initial pressure is reduced and cooled under the influence of the Joule-Thomson effect. Further, the cooled compressed air, bypassing the sump 6, is directed to the induction device, consisting of a winding 8, evenly located on the surface of the dielectric tube 9 and a heat-insulated metal case 10. At the same time, a signal from the central shield 7, a voltage is applied to the winding 8 of the induction device ( from batteries or an external source of electric current), which creates an alternating electric field, contactlessly transferring energy to a heated electrically conductive body, which is a section of a metal cylindrical high pressure pipeline located under a dielectric tube 9, as well as a thermally insulated metal body 10 (see Fig. . 2). The section of the high-pressure pipeline located under the dielectric tube 9 and the thermally insulated metal body 10 are rapidly heated under the influence of an alternating electric field, giving off thermal energy to the compressed air passing through the section of the high-pressure pipeline. The air heated in the induction heater enters the air distributor 11 and through the starting valve 12 into the engine cylinder (not shown in the figure).

The second mode is used in cases when compressed air heating is not required. In this case, the engine is started normally.

Compared to the prototype, the proposed system allows for high-temperature heating of compressed air of the air start system before it enters the engine cylinders and eliminates the unproductive air flow from the air start system.

Claims (1)

An air start system for an engine of military equipment with an induction heater, containing a central shield electrically connected to an electro-pneumatic valve, a cylinder with a high pressure line pneumatically connected to a felt air filter, a pressure reducer, a sump, an air distributor, a starting valve, a junction box, characterized in that it is installed a heat-insulated metal case, inside it there is an induction device, the winding of which is evenly placed on the surface of the dielectric tube.

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