St. Petersburg State Polytechnic University Department of Internal combustion engines TECHNICAL REPORT SUMMARY Head of department Professor Galyshev

Transcription

1 St. Petersburg State Polytechnic University Department of Internal combustion engines TECHNICAL REPORT SUMMARY Head of department Professor Galyshev Saint Petersburg, 2007 List of the executors: Shabanov, A. Yu, Ph.D., Associate professor Zaitsev AB, Ph.D., Associate Professor 1. Purpose of performing work The purpose of this paper is a comparative experimental study of the influence of additives in lubricating oil of NanoVit on the basic parameters of the gasoline carburetor engine - the effective power, fuel consumption, emissions figures and the rate of depreciation of the interfaces of friction. In the process of used equipment and methods of calculation and experimental study of working of an engine, developed by the Department of Internal combustion engines of the St. Petersburg State Polytechnic University. 2. Subject of the studies The study subject selected was the high-speed augmented carburetor automobile engine VAZ-2108 (4CH 7.6/7.1) produced by the Volga Automobile Plant.This engine is intended for installation in small class front-wheel-drive vehicles and is one of most common in Russia. The main parameters of the engine: Type - in-line four-stroke, carburetor gasoline engine with liquid cooling. Cylinders - 4 Bore, mm - 76 Stroke, mm - 71 Displacement, l Compression ratio Rated power, kw at n = 5600 rpm Maximum torque moment nm at n = 3400 rpm Type of fuel - high-octane gasoline A-92. This engine was used for all tests. 3. Description of test bench and measuring equipment Motor engine test on the VAZ-2108 were performed on the test bench laboratory at the ICE Internal combustion engines department of St. Petersburg university. The stand is equipped with systems that ensure its operation under all test conditions, and include monitoring and recording equipment which makes it possible to control and to record all necessary data for conducting a study of the parameters of the engine and its systems (fuel supply, cooling,etc).

2 To test the VAZ-2108 engine in the laboratory, the stand is equipped with the following systems and equipment: Braking system; Remote control engine instruments to monitor performance; A device for connecting the engine with a brake; Water cooling system for engine; Lubrication system for engine; Fuel system with a device for measuring the fuel consumption; Air supply system; Exhaust system. [Fig].1. Stand with the VAZ-2108 engine Engine test stand was also equipped with Equalizer dynamometer DS V with weights, torque sensor, photoelectric sensor and fan speed for an independent cooling Converter Leonard DP (motor-generator); Wiring closet 4 RN 2088 with dual inhibitory and excitatory control device to control the dynamometer speed and torque; cradle mounted dynamometer DS V with weights, torque sensor, photoelectric sensor (free-run speed sensor) and a fan for independent cooling; DP motor generator; Cable distribution head 4 RN 2088 with dual inhibitory and excitatory control device to control the dynamometer speed and torque; Console with control equipment, pointer speed (voltmeter graduated in 1/min., Accuracy class 1.5) and an ammeter. There is normal use of the engine lubricating oil system.

3 Instrumental error of measurement: Crankshaft speed, rpm 10.0 Torque, Nm 0.5 Fuel consumption, kg / h 0.01 The content of CO, CO 2-3% The content of CH, NO - 5% 4. Test program According to the procedure of accelerated tribological bench tests, accepted as the basis for conducting the independent examination, the program of tests included: Preparatory work: Dismantling, washing, visual inspection of the engine, measurement of its basic parts for fixation of the degree of wear; Weighing of piston rings and crankshaft bearings; Assembly of the engine, installation of the engine on the stand, connection to the load device, installation of the complex instrumentation. Further work steps: Stage 1. Base cycle of the accelerated wear tests of the engine. Running-in, conducted for 3 hours, to stabilize the engine parameters; Operation for preset time on the stand at fixed operating conditions, as prescribed by the procedure of the accelerated tribological tests; A series of tests simulating starting conditions; Removal of the engine from the stand, disassembly, fault detection, weighing items, the determination of wear and tear Re-assembly of the engine, installation on the stand, initial running-in period of 3 hours. Stage 2. Plotting of base curves for the engine using regular oil. includes: Measurement of performance of compression and gas-tight cylinder-piston group Step 3. Applying NanoVit additive includes: Processing of motor preparation in accordance with the recommendations of the manufacturer; Engine test bench for 40 HOURS on a fixed mode of securing his work; Periodic measurement benchmarks demonstrating the dynamics of the drug; The end of the test cycle is the removal of the engine characteristics: external speed and load at n = 2000, 3000 rpm with measurements of the main indicators of the engine; Metering and compression parameters of engine; plotting of the curves for the engine: external speed and load at n = 2000, 3000 rpm with measurements of the main indicators of the engine; Measurement of mechanical loss of engine power when the throttle open and closed; measurement compression and gas density of the cylinder-pistons Stage 4. Final cycle of accelerated wear tests. includes: Operation for preset time on the stand at fixed operating conditions, as prescribed by the procedure of the accelerated tribological tests; A series of tests simulating starting conditions; Removal of the engine from the stand, disassembly, fault detection, weighing items, the determination of wear and tear. Stage 5. Analysis of the test results The estimation of the effectiveness of the additive is produced from the following parameters: Change the size and degree of uniformity of compression of the cylinders;

4 Value of maximum power and maximum torque in absolute value and percentage terms; Values of specific fuel consumption in both absolute and percentage terms in the above atmospheric conditions; Changes in emissions for the CO, NO and CH before and after processing engine; Change the value of effective efficiency engine before and after treatment. The change in and degree of uniformity of compression on the cylinders; The value of maximum power and maximum torque in absolute value and percentage terms; Values of specific fuel consumption in both absolute and percentage terms under the given atmospheric conditions; Changes in emissions for the CO, NO and CH before and after processing engine; Change in the effective efficiency of the engine before and after treatment

5 Summary of Results a change in the torque of the engine of Venyukovsky Fittings Plant before and after working by preparation [NanoVit] (external speed characteristic) Change mechanical efficiency. the engine of Venyukovsky Fittings Plant before and after working by preparation NanoVit (external speed characteristic)

6 A change in the specific consumption of fuel of the engine of Venyukovsky Fittings Plant to and after working by preparation [NanoVit] ( full-load saturation curves, n=2000 r/min) A change in the specific consumption of fuel of the engine of Venyukovsky Fittings Plant to and after working by preparation [NanoVit] ( full-load saturation curves, n=3000 r/min)

7 Change in the moment of mechanical losses from the frequency of the rotation of crankshaft in different stages of tests (closed choke)

8 Measurements of cylinder compression were produced with the fixed frequency of rotation of the crankshaft at 250 r/min. The indications of compressometer and vacuum gauge were averaged over three measurements for each cylinder. Measurements were produced with the completely closed throttle plate. Data of measurements are given in Tables 5-7. Stage 1st cylinder 2nd cylinder 3rd cylinder 4th cylinder Before 12,3/12,7 9,0/9,3 12,4/12,8 12,9/13,3 Final state 11,9/12,4 8,2/8,6 11,9/12,2 12,9/13,1 Table. 5. Compression on the cylinders (numerator - the closed choke, denominator - the open choke) Stage 1st cylinder 2nd cylinder 3rd cylinder 4th cylinder Before the working by the 0,870 0,795 0,865 0,890 preparation Total state 0,845 0,760 0,855 0,870 Table. 6. Complete vacuum measurement on the cylinders. Stage 1st cylinder 2nd cylinder 3rd cylinder 4th cylinder Before the working by the 0,330 0,465 0,385 0,320 preparation Total state 0,325 0,465 0,355 0,310 Table. 7. Residual vacuum measurement on the cylinders. 8. Results of the measurements of the kinematic viscosity of the oil, at different test stages On the motion of tests were selected three tests of oil - fresh oil from the canister, the test of oil due to the state to the end of the base cycle of the accelerated wear tests (without the introduction of additive) and at the end of the total cycle of wear tests (with the additive). The measurements of kinematic viscosities were carried out at temperatures 50 and 100 deg. C. The results of tests are given in Table 10 below. Test T, deg. ν, cst Fresh oil At the end of the base cycle ,37 At the end of the total cycle (NanoVit) Test T, deg. ν, cst Fresh oil At the end of the base cycle At the end of the total cycle (NanoVit) Table. 10. The results of the measurements of the viscosity of the tests of motor oil, selected at different stages of the tests of additive NanoVit

9 On the basis of the results it is possible to make a conclusion about the degree of the influence of the additive on a change in the base viscosimetric properties of motor oil. From the data analysis, given in Table 10, it is possible to make the conclusion that the additive NanoVit somewhat increases hightemperature viscosity, also, in this case it reduces low-temperature. Consequently, the viscosity index of motor oil with its joint operation with the additive rises significantly. At the same time, viscosity changes do not exceed the limits permitted by the SAE classification for oils of class 10W Conclusions of treating the engine with NanoVit According to the results of the carried out work it is possible to make the following conclusions: - Adding NanoVit to the engine of Venyukovsky Fittings Plant-2108 led to the specific decrease in the level of mechanical losses, especially noticeable in the zone of the low and medium frequencies of the rotation of crankshaft (to 2000 r/min). This entailed the total reduction in the specific fuel consumption, also to a larger degree expressed in the zone of small revolutions. There was also an increase in the power of engine in entire range of operational characteristics. - The final averaged effects of the NanoVit treated engine are given in Table 11 below. This table gives the percentages of improvement/worsening in the indices, averaged on 20 measuring points, extrapolated according to the experimental data. Positive in the index indicate an improvement in the index in relation to the base values (at the end of the run), minus indicates a worsening. Power Averaged effects, % relative to the base Fuel Effective CO CH NOx consumption efficiency. Total state Table. 11. The averaged effects NanoVit treated engine - Oil pressure in the lubrication system after treating with NanoVit most notably increased in the zone of high rpm. In the basic version of the engine at greater than 3000 rpm, there was a clear downward trend in oil pressure. After treatment the engine pressure on these regimes rose from the region of bar to bar. It actually indicates some stabilization of gaps in the oil pump, as well as reducing the operating temperature of oil in the friction units due to the decrease of mechanical power losses in them. - The analysis of the change of the parameters of the engine in the course of working reveals the presence of a certain reduction in the effectiveness of engine at the initial stage of working, for the first 2-3 hours, after which begins the growth of the effect of NanoVit, which is amplified after the second application. An increase of CH in this stage of the tests is explained by the washing effect of additive. The stabilization of effect is achieved with an operating time of approximately hours, after which pronounced trends in engine parameters are not observed, all changes are within the error of measurement. At the same time, some deterioration of the airtightness parameters suggest redundancy of the concentration in motor oil. - In toxic gas analysis the most pronounced effect was on reducing nitrogen oxides. In general, when using the method of monitoring toxicity idling prescribed by GOST in real-life vehicles, we can expect a significant reduction in CO and CH in this mode. This is due to a significant decrease in mechanical power losses in the zone of low speed, allowing the use of poorer fuel-air mixtures while maintaining the target idle speed. - In analyzing the data on the rate of wear of friction units, of major note is the dramatic reduction of wear of bearing units compared to the baseline cycle. Moreover, some bearings have a slight gain in weight. This is probably due to the introduction of active particles in the additive structure of antifriction layer liners. At the same time, the mass loss of piston rings during the cycle of accelerated tribological tests has increased significantly. This is probably due to the presence of mechanisms micropolishing solid surfaces of cylinders and rings in the presence of active components of the additive. This is also confirmed by the appearance of parts recorded after the end of the test cycle. - As a whole, we believe that testing confirmed a pronounced positive effect of treatment of the NanoVit motor preparation. At the same time, we believe that its use requires additional studies to

10 formulate the optimal concentrations of the drug, successive cycles of treatments, depending on the dimension of the engine, such as lubricating oil, wear, etc. - It may be desirable to supplement the cycle of engine preparation with NanoVit after the first stage with the joint replacement of engine oil and oil filter to eliminate data from excess particles in the final stage.

11 APPENDIX 1 Photo-report according to the results of the tests of preparation NanoVit The exterior view of the piston of the engine of Venyukovsky Fittings Plant after NanoVit The exterior view of the piston of the engine of Venyukovsky Fittings Plant after NanoVit

12 The exterior view of the cylinder of the engine of Venyukovsky Fittings Plant after NanoVit The exterior view of the cylinder of the engine of Venyukovsky Fittings Plant after NanoVit

13 The exterior view of the bearing backings of the engine of Venyukovsky Fittings Plant after NanoVit The exterior view of the bearing backings of the engine of Venyukovsky Fittings Plant after NanoVit

14 The exterior view of the bearing backings of the engine of Venyukovsky Fittings Plant after NanoVit The exterior view of the piston ring of the engine of Venyukovsky Fittings Plant after NanoVit

15 The exterior view of the engine crankshaft of Venyukovsky Fittings Plant after NanoVit The exterior view of crankshaft bearings of the engine of Venyukovsky Fittings Plant after NanoVit