EXPERIMENTAL INVESTIGATIONS ON 4- STROKE SINGLE CYLINDER DIESEL ENGINE (C.I) WITH CHANGING GEOMETRY OF PISTON

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 9, Issue 13, December 218, pp , Article ID: IJMET_9_13_72 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed EXPERIMENTAL INVESTIGATIONS ON 4- STROKE SINGLE CYLINDER DIESEL ENGINE (C.I) WITH CHANGING GEOMETRY OF R. Siva Kumar Research Scholar, Department of Mechanical Engineering, JNTUA College of engineering, Anantapuramu, 5152, India, K.TirupathiReddy Professor, Dept of ME, RGM College of engineering and technology Nandyal, 51852, AP, India K.Hema Chandra reddy Professor, Dept of ME, JNTUA College of Engineering, Anantapuramu, 5152, AP, India, ABSTRACT The performance and emission characteristic of compression ignition engine with grooved piston was conducted. The piston geometry was changed into grooved piston by cutting V-grooves on piston bowl and make holes with the slots on piston crown, to create automatically swirling motion of air in suction stroke (reference of STRATIFIED CHARGE ENGINE).All the experiments were conducted at constant speed 12 RPM with diesel. The test results gives BTE and SFC are given optimum compared to normal piston operated with basic fuel. By changing the geometry of the piston it given good combustion results and reduced the emissions HC and NOX emissions are reduced moderate, smoke also slightly reduced compared to normal piston results. Keywords : Swirling motion, Stratified charge engine, V-grooves, Brake Thermal Efficiency, Piston Geometry. Cite this Article: R. Siva Kumar, K.TirupathiReddy and K.Hema Chandra reddy, Experimental Investigations on 4-Stroke Single Cylinder Diesel Engine (C.I) with Changing Geometry of Piston, Journal of Mechanical Engineering and Technology, 9(13), 218, pp INTRODUCTION The increase temperature in the compression stroke to ignite a fuel charge in CI engine. The most important factor is to control the combustion process. In diesel engines to control the fuel air mixture in suction process, the fluid flow prior to combustion to generate the burning rates. In combustion, emission and performance process the air motion is very important role for proper fuel air mixture. In direct injection diesel engines to obtain a better combustion and reduced the editor@iaeme.com

2 R. Siva Kumar, K.TirupathiReddy and K.Hema Chandra reddy emissions. Swirl can increase the rate of fuel air mixture; squish flow increases turbulence levels in combustion process for proper mixing. The piston geometry has a significant effect on air flow there by resulting in better atomization, better mixing and better combustion when piston moves from TDC during section stroke. If the compression ratio is too high there is a chance to have knocking if too much turbulence leads to successive heat transfers for the gases to the cylinder walls and may create problems on flame propagation. If the sufficient air in contact with the injected fuel particles, to provide complete combustion at a constant rate, the piston crown and cylinder head are shaped to induces a swirling motion to air while piston is moving from BDC during compression. The swirl can generated in the diesel engine by modifying the parameters in the engine, there are cylinder head, piston i.e., modification of combustion chamber and inlet manifold. Piston crown is modified i.e. alteration of combustion chamber to increase the turbulence in the cylinder. This intensification of the swirl is done by cutting grooves on the crown of piston and bowl of piston, the grooves are intensify the swirl for better mixing of fuel and air and their effects on the performance and emission. Swirl, squish and tumble are the important flow pattern of air motion. These patterns not only affect the air fuel mixing and combustion process in diesel engine and combustion. In the combustion process combustion of fuel inside the cylinder, Air swirl fuel quantity injected to improve the performance and to eradicate the emission characteristics of CI engine. To produce a squish and swirling action which can improve the fuel air mixture formation before ignition takes place in the modification of Piston bowl geometry. As the piston moves upward the gas is pushed into the piston bowl. 2. LITERATURE REVIEW S. Vedharaj, R. Vallinayagam, W.M.Yang, C.G. Saravanan B, P.S Lee was carried out for the effective operation of KME (Kapok Methyl Ester) diesel blends to optimize the combustion bowl geometry of a single cylinder diesel engine there are two different combustion chamber geometries i.e., TRCC and TCC in addition to design of HCC are used TCC was shown to exhibit best performance emission then TRCC and HCC for all blends. B5 is shown a 5.2 % increase in BTE them diesel with TCC [1]. S. Jaichandar, K Annamalai was found that to improved thermal efficiency, reduction in fuel consumption and pollutant emissions from biodiesel fuelled diesel engine rapid and perfect air fuel mixing in the most important to set good results. The best injection parameter and better design of combustion chamber are obtained to proper mixing quality of biodiesel and air. The experiments are carried out at different operating process of 185, 2,21,22 bars. Experiments were performed with HCC and using DI diesel engine with a convert type injection system. The combined effect of varying injection processor and combustion chamber geometry using 2% of POME by volume to evaluate on the combustion, performance and emission parameters. The test results optimized that improved in BTE and SFC for TRCC operated at higher injection pressure [2]. Prasad et.al, (211 a and 211 b) and Prasad and pandererfedes (213) experimental investigation of the air swirl in cylinder to get performance and emission of single cylinder diesel injection engine is used. The different swirl intensities in the cylinder there design parameters have been changed the cylinder head, piston crown & inlet duct the piston crown is modified i.e. the change the combustion chamber designed to get turbulence in the cylinder. The swirl is done by cutting grooves on the crown of piston. The better mixing of air and fuel and their effects on performance and emission by grooves.[3] Bajpai et.al. tested performance and emission parameters of Karaja SVO blending with diesel and without engine modification blending up to 1 tests in engine to study the effect of injection operating pressure on performance, emission and combustion Para meters of diesel engine using on blends of karanja, SVO.[4] editor@iaeme.com

3 Experimental Investigations on 4-Stroke Single Cylinder Diesel Engine (C.I) with Changing Geometry of Piston SL Prasad et.al express introduction on influence of the air swirl in cylinder on performance and emission of a single cylinder DI engine. In order to improve the difficult swirl intensities, there design parameter have been changed the head, PC and inlet duct. The piston crown is modified. The performance is obtained by different geometry of piston.[5] CD Rakopoulos, GM Kosmada Kis, E.G. Pariotis was investigate using three piston bowl geometries for three engines rotational speed of 15, 2 and 25 RPM. These geometries are produced by changing the ratio of piston bowl dia to cylinder from 64% to 54% and 44% increasing the piston bowl height in order to keep The compression ratio is constant, compare the results it can be concluded both models predict quite similar mean cylinder pressure and temperature over the whole closed part engine cylinder.[6] 3. EXPERIMENTAL SETUP The experimental setup conducting single cylinder four stroke diesel engine coupled with eddy current dynamo meter. The test will conduct 24 PE IC engine software. With normal piston by applying load on eddy current dynamo meter kg and consider the readings of emissions, smoke and fuel consumption per minute. Repeat the same to loads 3kg, 6kg, 9kg and 12kgs. Completing all readings give 1hr rest engine and change the normal piston to grooved piston. Further the necessary modifications on the piston crown and piston bowl can be easily carried out in this engine. The engine is allow to run about 2min with normal piston so it gets warmed up and steady running conditions are obtained the experiments were conducted in diesel engine with grooved piston to know the performance and emissions. The software is used for regarding test parameters i.e., fuel flow rate, temperature, airflow rate and speed for calculating performance parameters i.e., BP, BTE and SFC, CV and density of particular fuel are fed to the software for calculating parameters are i.e., CO, UBHC, NOx were measured. Figure 1 Experimental setup MODIFICATION MADE TO Turbulence is very important in mixing and combustion of fuel with air in CI engine. The turbulence was induced by modifying the normal piston to a modified piston this was done by adding 6 holes D8 and 6 mm depth with 2x2 slot each hole on crown and 7V - grooves on bowl. If the end of compression strokes the fuel vapour squeezes into modified piston spirally due to direct compression which leads to the enhancement of turbulence for better mixing and combustion editor@iaeme.com

4 R. Siva Kumar, K.TirupathiReddy and K.Hema Chandra reddy Figure 2.Configuration of piston geometry Table 1:Engine Specifications No. Of cylinders 1 No. Of strokes 4 Cylinder diameter 87.5 mm Stroke length 11 mm Orifice diameter 2 mm Dynamo meter arm length 185 mm Speed 15 RPM Power 3.5 kw 4. RESULTS AND DISCUSSIONS 4.1. PERFORMANCE PARAMETERS BRAKE POWER VS BTE. The BTE of the engine is one of the most important parameter for finding the performance of engine. The variation of BTE with respect to load for piston with grooves and normal piston. It indicates the combustion behaviour of the engine it is noticed that the BTE of engine increased with increasing loads. BTE of convention engine at the maximum load is found to be % with diesel fuel whereas BTE of engine with grooved piston is found to be 32.9% with 1.64% is improved. Due to the enhanced air swirl in the combustion chamber which resulted in better mixing of air fuel ratio as well as complete combustion of the change in combustion chamber editor@iaeme.com

5 Experimental Investigations on 4-Stroke Single Cylinder Diesel Engine (C.I) with Changing Geometry of Piston BRAKE THERMAL EFFICIENCY % BRAKE POWER Vs BRAKE THERMAL EFFICIENCY % BASIC BRAKE POWER IN kw Figure 3: B.P vs. B.T.E BRAKE POWER VS BSFC The variation of BSFC with respect to BP. The fuel consumption decreases with increase the load. It can be observed that BSFC is maximum for normal piston and minimum grooved piston the BSFC of the engine is.3kg/kw hr at full load. Whereas the BSFC of engine with grooved piston is.25 kg/kw-hr. Because of complete combustion of change in combustion chamber by liberating maximum energy due to the inducement of enhanced air swirl in combustion chamber. SPECIFIC FUEL CONSUMPTION IN kg/kwh BRAKE POWER Vs SPECIFIC FUEL 5 CONSUMPTION IN kg/kwh BRAKE POWER IN kw Figure 4 BASIC BRAKE POWER VS VOLUMETRIC EFFICIENCY The variation of volumetric efficiency for piston (normal) with grooved piston as shown figure. It is observed that the volumetric efficiency is minimum for normal piston and maximum for grooved piston. The breathing capacity i.e. the volumetric efficiency of grooved piston engine is improved.81% when compare with normal piston at full load condition the volumetric efficiency values are of 74% for normal piston and 75% for grooved piston editor@iaeme.com

6 R. Siva Kumar, K.TirupathiReddy and K.Hema Chandra reddy VOLUMETRIC EFFICIENCY % BRAKE POWER Vs VOLUMETRI EFFICIENCY % BASIC BRAKE POWER IN kw Figure 5: B.P vs. V.E 4.2. EMISSION PARAMETERS HC VS LOAD The variations of HC emissions in the exhaust. Due to incomplete combustion the UBHC emission is obtained with increase in turbulence to decrease the HC emission. Maximum reduction of HC emission levels in the grooved piston. When compared with normal piston. From the results of idle speed the HC emission for standard engine is found to be 85ppm where as HC emission for the engine with grooved piston is 75 ppm at full load condition i.e. 1 ppm of emissions reduced for piston with grooved piston compared with normal piston. HC in ppm LOAD Vs HC BASIC LOAD in kg Figure 6: Load Vs H.C CO VS Load CO emissions are controlled by the air fuel ratio. The variations of CO with respect to load are observed for normal piston with grooved piston the CO emissions of piston with grooves is lower than the normal piston. Diesel engines work with lean mixtures. But it may be rich mixture and leads to the formation of CO. CO emission decreases with increasing load for any condition. The CO emission is.9% at grooved piston and.1% at modified piston condition editor@iaeme.com

7 Experimental Investigations on 4-Stroke Single Cylinder Diesel Engine (C.I) with Changing Geometry of Piston CO in % vol LOAD Vs CO BASIC LOAD in kg Figure 7: Load Vs CO NOx Vs Load Nitrogen oxides are known as an air contaminants formed through the combustion of fossil fuels and other fuel that contain nitrogen. The variations of NOx emission for normal engine with grooved engine with load. The NOx emission is better reduction as grooved piston 879 PPM volumes when compared with normal piston at constant speed full load condition combustion of nitrogen free fuels at high temperature in the presence of air oxidizes the nitrogen producing nitric oxides. At initial load the NOx is zero. At full load the Nox for grooved piston is 2 PPM and the normal piston is 3 PPM. NO X in ppm LOAD Vs NO X BASIC LOAD in kg Figure 8. Load Vs NO x Smoke Vs Load The variations of smoke with load at different conditions. The smoke variation also less in grooved piston compared with normal piston at maximum load constant speed condition. If it is around 3.5% opacity is decreasing in grooved piston engine. Smoke forms due to incomplete combustion of air fuel mixture and formed rich mixture. Smoke percentage increases with increase the load as a result increase in fuel consumption editor@iaeme.com

8 R. Siva Kumar, K.TirupathiReddy and K.Hema Chandra reddy SMOKE in % opacity LOAD Vs SMOKE BASIC GROOVE D LOAD in kg Figure 9: Load Vs Smoke 5. CONCLUSIONS Piston geometry was studied for performance and emission parameters to obtain fuel economy benefits the experimental investigation of grooved piston with normal piston on a single cylinder 4 stroke diesel engine and conclusions of the test results are given below. 1. The SFC is noticed to be reduced by.25 kg/kw-hr of grooved piston compared to normal piston. When operating at full load, 15 rpm speed. 2. The maximum increase in BTE of grooved piston to normal piston is found to be 1.64%. 3. The maximum increased in volumetric efficiency of grooved piston is improved.81% when compared with normal piston at full load condition. 4. The HC emission for grooved piston is reduced by 1ppm, 5. The CO emission for grooved piston is reduced by.1%. 6. The NOx emission for grooved piston is reduced by 879 ppm. 7. The smoke emission for grooved piston is reduced by 3.5% opacity. From the above conclusion the grooved piston configuration can be suggested on engine compared with the other piston configuration. diesel REFERENCES [1] S vedharaj et al. Optimization of combustion bowl geometry for the operation of kapok biodiesel-diesel blends in stationary diesel engine Journal of fuel.vol 139, 215, pp [2] S. jaichandar et al. Combined impact of injection pressure and combustion chamber geometry on the performance of a biodiesel fuelled diesel engine Journal of the Energy, vol xxx, (213), 1-1. [3] Prasad S L V, et al (211a), The Effect of air swirl in a dieselengine, African journal of scientific research, vol.3, no.1, pp , ISSN: [4] Bazpai,et al the effect of injection operating pressure on performance,emission and combustion parameters of diesel engine using blends of karanza,svu journal of energy, vol 2,no.2,pp ,ISSN: [5] B.V.V.S.U.Prasad et al. High swirl-inducing piston bowls in small diesel engines foe emission reduction journal of applied energy,vol88,(211) pp [6] C.D.Rakopoulos et al. investigation of piston bowl geometry and speed effects in a motored HSDI diesel engine using a CFD against a quasi-dimensional model General of energy conversion and management,vol 51(21), editor@iaeme.com