CC BY
6
Section 7. Transport
Kayumov Bakhrom Abdullajonovich, Researcher of Andijan machine-building institute,
Republic of Uzbekistan, E-mail: kayumov-bahrom74@mail.ru
RESEARCH OF PROCESS OF GUMMING OF GASOLINE ON SURFACES OF ELEMENTS OF A FUEL SUPPLY SYSTEM OF ENGINES
Abstract: The article examined pollution gasoline supply system elements of engines denial. Classified chemical structure of pollutants. Identify the types of failures caused by when applying contaminated fuel. Designed laboratory facility for testing of injectors and fuel pumps on measuring reliability. Conclusions leading to failure of supply system elements of engines in service in road and climatic conditions, hot and dusty regions.
Keywords: gasoline, engine, reliability, power system, dusty region, a hot climate, an injector, a fuel pump.
1. Introduction
The results of performance tests have shown [1; 2], that the basic quantity of refusals of elements of a power supply system, occur owing to impurity of fuel, and in the general list of the refusals caused by gumming because of use of poor-quality gasoline in an injection power supply system of engines appear.
One of the basic requirements for ensuring operational reliability of an injection power supply system of engines is application of qualitative fuel and lubricants. However, at the time of the observations found that quality used car controlled engines, gasoline in most cases do not meet the requirements of the standard, particularly on the content of mechanical impurities in them, water and jet black. The fuel can also contain sulfur, oxygen and nitrogen compounds.
2. The analysis of pollutants of gasoline
Gumming and asphalt substances (pitches, asphal-
tene's, etc.) belong to the complex cyclic compounds in which the molecule along with carbon and hydrogen is still composed of oxygen and sulfur.
Chemical structure ofbituminous/asphalt substances have not yet been resolved, and therefore the classi-
fication is based on a different ability to dissolve in oil products. This classification distinguishes:
- neutral resin-high viscosity liquid or amorphous solid density about units, well dissolved in all liquid oil products;
- aromatic hydrocarbons in gasoline, with its high ant detonation properties, however, the content of more than 40% of sharply increased soot formation in the engine and the ability of a deposit to be kept (not to burn out) on a surface of details, strengthening possibility surface ignitions;
- asfalteny - the firm fragile substances painted in brown or black colour and possessing in density above unit;
- sour pitches in density above unit are outwardly similar to neutral pitches, and unlike the last sour pitches it is not enough soluble in the hydrocarbonic environment, but in gasoline at all soluble, therefore in process of formation they drop out of oil products and settle on details and power supply systems in the form of sticky adjournment.
Basic parameters driving the quality of motor gasoline are: density; octane number; content components
of the octane, the vapour pressure, the actual content of actual pitches and sulphur.
With rising temperature environment increases propensity of formation of pitch in gasoline.
3. Kinds of refusals of a power supply system of the engine
The use of leaded gasoline, even with bromic bear, leads to undesirable phenomena in operation [1-6]:
• Raised ash-forming in connection with increase in maintenance lead tetraethyl (80-85% of lead in a deposit on final valves and candles and 50-70% - on pistons and heads of blocks of cylinders);
• The raised propensity to surface ignition;
• To decrease in reliability of work of candles and final valves;
• To non-uniform distribution bear on cylinders which results raised ash-forming;
• Corrosion to action on metals in the presence of water;
• To decomposition lead tetraethyl at long storage that reduces detonation firmness of gasoline, etc.;
• To increase toxicity;
• To go up gumming.
4. Climatic features of the central asia
The main characteristic of operation of the cars the conditions of the Central Asia is high temperature and air dust content.
During the flight period day absolute maximum temperature of air in the conditions of the Central Asia (June-September) fluctuates from + 37 to + 470 Celsius. In a cabin of the car the temperature reaches from + 45 to + 480 Celsius, and under a cowl from + 80 to + 900 Celsius [3]. It leads to that oxidation and gumming gasoline in environmental conditions of the Central Asia is accelerated. As a result gasoline gets yellow-brown color, and on capacity walls at storage there is a layer of resinous substances.
At use of such gasoline on walls of a fuel tank, fuel of wires, the fuel pump, the filter of rough and thin clearing, an injector, a regulator of pressure and other details of a power supply system can be formed resinous adjournment in the form of a skintight brown layer similar unguent consistencies. At car operation on the gasoline containing a small amount of pitches (within norms, admissible the standard on gasoline), in an injection power
supply system it is formed only small adjournment which practically are not influencing for work of a power supply system, but in due course mechanical impurity in the form of a soil dust, grains of sand etc. being in gasoline are capable to stick to earlier formed adjournment in a power supply system and to adsorb on the surface new resinous substances. At use of gasoline with the raised maintenance of pitches it is possible formation of the adjournment, capable to cause infringement of standard work of a power supply system. The basic amount of refusals caused gumming are meeting in injectors.
Therefore for the purpose of reduction of influence of process of gumming by indicators of reliability of an injection power supply system of engines there was a task in view: to investigate gumming process in a power supply system of cars in laboratory-bench conditions.
By working out of laboratory installation, first of all, started with to provide identity of operating modes of elements of an injection power supply system of engines in laboratory-bench conditions with operational.
5. Designed of the laboratory stand
Designed laboratory facility for testing injection system engine power is a fixed installation (fig. 1 and 2), equipped with rotary flowmeter, with calorimeter and gauges of temperature 5, a manometer 6, a fuel tank 1. Fuel is fed into the system under pressure of 310 kPa with the help of the fuel pump 2. The fuel flowing through pipelines and 4 filter served to fuel a ramp, which has 7 injectors and pressure regulator 8. Fuel consumption is monitored using a flowmeter 5 and is determined by the fuel temperature, thermometer and pressure gauge is determined by using pressure in the pipes (fig. 2). Electric fuel pump and injector electric contacts are connected to the network through electric-transformer 1.
To change the temperature (T) power system operation mode is performed electrically, for which each injector fuel heaters are installed (figure. 1). Changes the pressure in the system can be achieved with an electric fuel pump to increase the pressure (P) in the system increases the pump output (Q), and to decrease-decrease.
Electrical wiring installation (fig. 1) worked under voltage: 220 v, to which it is connected to the general network via current converter.
In the process of conducting the experiment created high-temperature operating conditions the work
of injection system. To do this, the temperature of the account it installation provides possibility of work of
gasoline in the food system has been changed in several an injection power supply system of engines in various
ranges of temperature changes corresponding to different ranges of change of ambient temperature and gasoline,
regions of operation of cars in Uzbekistan. Taking into i. e. as ordinary, and high-temperature conditions.
Figure 1. The electric scheme of laboratory-bench installation for test of an injection power supply system of internal combustion engines: 1 - switch; 2 - injectors; 3 - transformer; 4 - roadway the scheme of transformation of an electric current; 5 - electric motor of the fuel pump; 6 - voltmeter; 7 - ampermeter
Figure 2. The hydraulic scheme of laboratory-bench installation for test of an injection power supply system of internal combustion engines: 1 - tank; 2 - the pump filter; 3 - fuel pump; 4 - fuel filter; 5 - manometer; 6 - flowmeter; 7 - injectors; 8 - regulator of pressure
6. Results of tests work of inj ectors. The greatest quantity of adj ournment
Tests have shown that formations of resinous ad- forming round dot apertures of injection of an injector, j ournment are rendered by the greatest adverse effect on cases of overlapping of apertures were thus observed by
the resinous firm adjournment which were at the bottom of gradual stopping delivery of fuel.
Gumming adjournment, sticking to internal walls of an injector, lead to a motionless condition of its rod therefore there is an injector failure.
According to the results of the tests also revealed that there were cases clogging the resinous substances internal channels of the pressure regulator, leading to an increase in pressure in the fuel rail, which helps increase fuel consumption.
Research of different grades of gasoline has shown that character of course of process of gumming on all tested grades of fuel have about identical sequence. It follows from this that all grades applied in cars gasoline
during operation start to be oxidised with the subsequent formation gumming remitted on details fuel supply system engines.
7. Conclusions
Thus, results of tests have shown that at operation of cars with an injection power supply system of petrol engines in hot-environmental conditions territory of Uzbekistan cases of essential gumming in fuel supply system which reason is both applications of poor-quality grades of gasoline, and influence of high temperature of the environment, leading to acceleration of process of oxidation of gasoline and subsequently formations of resinous adjournment on power supply system details are observed.
References:
1. Kayumov В. A. Analysis of element failure distribution patterns in inj ection fuel supply system by the method of spline functions // Herald of Kurgan State university. Series "Technical sciences". Russia, Kurgan, - 2014. - No. 2. - P. 73-75.
2. Kayumov B. A. Experimental Study of Reliability Indicators Injection Feeding System of Gasoline Engines in Road and Climatic Conditions of Central Asia // Journal of Siberian Federal University. Engineering & Technologies, - 2016. - No. 9. - Issue 1. - P. 86-104.
3. Каюмов Б. А. Влияние химической стабильности бензина на надежность системы питания двигателей с электронно-точечным впрыском топлива // Научно-технический журнал ФерПИ. - 2003. - № 1. - С 76-79.
4. Martyr A. J. & Plint M. A. Engine Testing, Theory and Practice. Third edition. Oxford / Published by Elsevier Ltd. - 2007. - 441 p.
5. Крамаренко Г. В., Салимов А. У, Каримходжаев Н.Т, Каюмов К. К. Качество топлива и надежность автотракторных двигателей. - Ташкент. Фан. - 1992. - 118 с.
6. Recommendations for Cleaning and Pretreatment of Heavy Fuel Oil. Alfa Laval. London.
