CC BY
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Section 8. Transport
Section 8. Transport
Musurmanov Ravshan Kurbanmuratovich, Doctor of technical sciences, Director of Tashkent Institute of Irrigation and Melioration Bukhara Branch
Utaev Sobir Achilovich. competitor Research E-mail: Utaev.s@list.ru
Power-ecological indicators of diesel engine at work on alternative fuel
Abstract: This article presents the results of research on the production and use, alternative fuels. It sets out the essential characteristics of engines using alternative fuels.
Keywords: the biomass, alternative, motor, bioethanol, Methanol, biofuel
By the government of the Republic of Uzbekistan there were accepted number of programs on economy and an effective utilisation of oil power resources. One of ways of the decision of this problem is application of alternative energy sources, in particular, motor-fuel.
According to a number of experts, the biomass can become in the future a considerable source for the reception of motor-fuel (biofuel) and first of all in the countries located in warm climatic zones. Liquid fuel is extremely important because of convenience of use and good management of combustion in power installations.
According to the scientists of the foreign countries who are engaged in kinds of fuel sated oxygen, bioethanol can mix up or turn to the emulsion with fuel kinds (also with diesel fuel) with high quality of ignition [2; 4]. Methanol, even when dry, not completely mixes up with diesel fuel and can be corrodent.
In this work results of researches on reception and application of bioethanol as additives to traditional fuels are stated. For dehydration of the bioethanol received from the waste of a biomass, the new nonconventional method — a complex of membrane processes, including nano-filtration and evaporations through the membrane, replacing traditional azeotropy rectification is applied.
In this connection Germany, the USA, Japan, the Netherlands, Brazil and a number of other countries conduct intensive workings out of power saving up methods of division, including membrane ones, capable to replace azeotropy rectification. Membrane processes vary in their simplicity and profitability [1].
At bioethanol dehydration technology, impurity as the higher spirits (fusel oils) and difficult ethers remain
as a part of bioethanol which can positively influence miscibility with oil products and combustion process.
At use of biofuel as additives to traditional fuels power and ecological problems are solved simultaneously.
High solar radiation in Uzbekistan and good productivity of sierozem soils promote reception ofbig crops of fTuit-and-vegetable production at low expenses. Therefore from a waste of this production (apples, grapes, vegetables etc.) it is possible to make cheap fuel bioethanol. By preliminary spent calculations, at processing of agricultural products (grapes and apples) on canneries and wineries of the Republic it is formed more than 300350 thousand tons of a waste in a year. At additional processing of this waste by incorporated means, it is possible to receive 25-30 thousand tons of bioethanol.
However till now alcohol fuel has not received distribution because of two principal causes: higher cost ofbio-ethanol in comparison with oil fuel and absence of technical or economic advantages compensating this high cost.
Heightened interest to alcohol fuels, especially to bioethanol, is caused now by following reasons
Bioethanol can be made from a biomass on advanced technology and competitive price;
• Bioethanol can be stored and be distributed like as oil fuel;
• Bioethanol in ecological aspect is more comprehensible, than other non-oil fuels; because at work on it the maintenance of pollution in the fulfilled gases is less;
• By addition to oil fuels a bioethanol to 10-15% it is possible considerably increase resources of oil fuels.
Data concerning power means with the installations adapted for the work on bioethanol or its mix with oil fuels in the literature are rather limited [1; 3; 4].
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Power-ecological indicators of diesel engine at work on alternative fuel
Therefore our main objective was reception of the all-round information towards the possibilities of use of bioethanol in conditions of dry hot climate.
For definition of dependence of capacity, fuel profitability and other indicators of work of the engine on bioethanol-holding fuel from a parity between fuel and air adjusting characteristics serve in a gas mixture on mix structure. They give a chance to establish normal operational adjustments of the structure of mix, and also their expedient limits from the point of view of achievements of the set efficiency, fuel profitability and toxicity. In these purposes the stand of test of diesel engine D-21 is improved and the tests by the special technique are conducted. Results of initiation of diesel engine D-21 at work on standard diesel fuel and 8% of bioethanol mix with diesel fuel have shown that at
diesel engine work on 8% ofbioethanol mix with diesel fuel burning process begins in a point 2 , the delaying period of the ignition of the mixture increases. The period of fast burning proceeds from a point 2 ‘ to a point 3 '. The maximum increase of pressure corresponds to the piston approach to the top dead point. At burning from a point 3 ' to a point 4 ' the big thermal energy is allocated. At diesel engine work with diesel fuel with 8%-s’ mixtures of bioethanol pressure in the cylinder p increases a little. So, at «=1600 mines-1 on standard fuel size p =5,95 мПа, on 8% of mixture pressure in the cylinder pmax=6,13 мПа. In pic. 1 — the adjusting characteristics on a corner of an advancing of giving standard diesel fuel and 8%-s’ mixtures of bioethanol with diesel fuel of diesel engine D-21, removed on a nominal mode are resulted.
Adjusting characteristics of diesel engine on an adjusting corner of advancing of the fuel injection beginning
1 — standard diesel fuel;
2 — a fuel mixture of bioethanol with a diesel fuel.
Pic. 1. Adjusting characteristics of diesel engine on an adjusting corner of advancing of the fuel injection beginning
From characteristics sle-blows that the maximum effective power N =15,8 the kilowatt and minimal specific fuel consumption g =248 g/kilowatt-hour are received for an advancing of the beginning of giving the standard diesel fuel at 18 ° an angle of rotation of a crankshaft to the top dead center (TDC). Thus the maximum capacity N =16,9 the kilowatt and the minimum spe-
emax
cific fuel consumption g =250 g/kilowatt-hour are re-
emin
ceived for an advancing of the beginning of giving 8%-s’
mixtures of bioethanol with diesel fuel at 15 ° ™ angle of rotation of crankshaft to TDC.
From this it follows that at work of diesel engine D-21 on 8%-s’ mixtures of bioethanol with diesel fuel N on 6-8% above, than at diesel engine work on standard diesel fuel. This results from the fact that bioethanol as additives to the basic fuel improves combustion process as in the structure has dissolved oxygen.
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Section 8. Transport
Besides, at bioethanol the latent warmth of transformation (850 kdzh/kg) in 3-5 times more, than at diesel fuel (250 ... 270 kilojoule/kilogramme) and at gasoline (330 kilojoule/kilogramme) that in some cases provides positive effects — decrease in temperature of a “fresh” portion of fuel and increase engine filling. The maximum temperature of a cycle also decreases that positively influences decrease in issue of soot. Hour fuel consumption practically remains to constants as the adjusting characteristic acts in film at the set frequency of rotation and invariable position of a lath of the fuel pump.
Specific fuel consumption changes depending on a corner of the beginning of injection of fuel as function, back to capacities (pic. 1). Therefore extreme values of capacity and specific fuel consumption at the same coal of the beginning of fuel giving coincide. At early and late corners capacity decreases, and specific fuel consumption grows. An advancing optimum angle size of the beginning of injection depends on a number of factors which concern: frequency of rotation of the crankshaft, engine loading, way of carburetion, the law of fuel-giving, entry conditions on an admission and release of the mixture of a bioethanol with a diesel fuel.
Comparative traction characteristics of the tractor TTZ-60 at work on standard and bioethanol-containing fuel have shown that at use of a mix capacity and traction effort increase on 6 ... 8%, and specific fuel consumption decreases on 6 ... 7% at identical valid speed of the tractor. It is because of the improvement of combustion process at the lack of work overloads air of the engine at dissolved oxygen expanse as a part of bioethanol that indirectly proves reduction of exhaust gases especially in a correct zone.
At use of bioethanol-containing fuel combustion process comes nearer to the optimum period of combustion that speaks about decrease in temperature of fulfilled gases.
Characteristics of capacity curves, twisting moment and specific fuel consumption of engine show that in a correct zone rated power and twisting moment curves increase, and the specific expense of bioetanol-containing fuel decreases. It leads to increase of labour productivity of machine-tractor aggregates and decrease of fuel consumption on performed work unit.
The complex researches spent on a condition of piston-cylinder-unit group details at use in oxygen-containing, i. e. bioetanol-containing fuel, showed the following.
Sleeves of cylinders wear out non-uniformly both on forming, and on a circle in cross-sectional view. The deterioration peak on forming settles located on the stop place of compressive ring in top dead center.
Researches on the size and character of working surfaces deterioration of sleeves were spent by micrometry with the subsequent statistical data of given micrometreage.
By ferro- and spectrographic research methods it is revealed that deterioration products in engine oil at various fuel have the various sizes, spherical and helical (spiral) forms (tab. 1).
Small particles of deterioration products at work on standard fuel have a cover from resinous substances — graphite structure. Depending on operation time of the engine the lump of large particles from the beginning sharply increases in engine oil, and then decreases. The iron maintenance in deterioration particles rises with an increase in their lump.
Table 1. - The size of products of deterioration and the maintenance of iron in them at engine work on various fuel
Duration The engine works on standard fuel The engine works on bioethanol-containing fuel
of the work The size of deterioration Maintenance of The size of deterioration Maintenance of
of engine, particles, micron Fe in deterioration particles, micron Fe in deterioration
hour The larges The smalls products,% The larges The smalls products,%
10 90 80 12 88 84 13
50 135 93 40 130 95 41
250 155 112 53 142 115 51
400 125 115 61 121 123 59
600 141 119 78 130 121 75
Changing the structure of covering details of CPG and selecting various additives in engine oil, it is possible to influence frictional properties of rubbing pairs, achieving rational characteristics of deterioration of CPG.
Dependence of deterioration details of CPG on the size of varnish particles and their concentration in en-
gine oil at work on standard fuel (respectively 1, 2) and bioethanol-containing fuel (respectively 3, 4).
At work on bioethanol-containing fuel it is observed an alteration of the portion of large and small particles of deterioration. Experiences have shown that deterioration products in engine oil consist of particles with metallic
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Power-ecological indicators of diesel engine at work on alternative fuel
basis and particles from organic connections — a var- CPG. At use of bio-ethanol-containing fuel with opti-nish, analogical to graphite by the structure. Presence of mum concentration there formed less varnish, because
a varnish at engine oil raises deterioration of details of of what deterioration (pic. 2) little decreases.
Pic. 2. Dependence of deterioration details of CPG on the size of varnish particles and their concentration in engine oil at work on standard and bioethanol-containing fuel
Details deterioration of CPG at work on biofuel mixture depends on speeding and loading modes of their work. So, average speed of deterioration on idle running is in 6,2 ... 9,9 times less, than at maximum loading. On maximum high-speed mode and loading of engine concentration of iron (Fe) has increased in engine oil from 1,Ы0-4 to 7,8-10-4 g/hour that on 8-12 % it is less, than at work on standard fuel.
Cylinders sleeves of engine SMD-22, fulfilled between-repairs resource on standard diesel fuel and on bioethanol-containing fuel, have average deterioration 0,13 ... 0,21 mm, the maximum deterioration of a sleeve on standard diesel fuel does not exceed 0,33 . 0,47 mm, the maximum deterioration of a sleeve
on bioethanol-containing fuel 0,37 ... 0,49 mm. Arithmetic-mean values of wear process are received on the tests basis of 16 engines SMD-22 working on various kinds of fuel at change of adjusting indicators on rational sizes.
For the reception of authentic results on cylinders' sleeves deterioration the kit ofparts, sufficient for carrying out of researches was defined at the set size of confidential probability a0=0,94 and a relative error 8=11 %.
Deterioration of top compressive ring for 400 work-hours has made 0,255-0,470 g, i.e. on 4-7 % it is less, than at engine work on standard fuel.
Thus, it is experimentally established that mixes of bioethanol solutions to 8 % can be used as a diesel fuel, and mixes of solutions to 10 % can be used as autogasoline under condition of its full dehydration. Also it is established that the bioethanol received from the waste, it is possible to use as additives to the fuel of low-speed diesel engines and household fuels.
It is revealed that at diesel engine work on 8 % of bioethanol mixture with diesel fuel the maximum effective power Nemax is on 5-7 % above, than at diesel engine work on standard diesel fuel, and issue of soot particles in fulfilled gases decreases on 9-12 %.
References:
1. http://www.autoconsulting.ua/article.phpsid=9451
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3. Alternative biofuel from rape oil derivatives a. P. Marchenko and v. G. Semenov udc 662.75:629.7 (chemistry and technology of fuels and oils, vol. 37, no. 3, 2001).
4. Panchal C. I. et al. Fermentation ethanol production - application of the new genetics to an ancient art: Energy Technol//Appl. and Econ. proc. 11th Energy Technol. Conf. Washington, 1984. P. 1270-1273.
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