MECHANICAL ENGINEERING, EXPERIMENTAL ANALYSIS OF THERMAL BARRIER COATING ON DIESEL ENGINE PERFORMANCE PRESENTED BY, M.V.KRISHNAMOORTHY PREFINAL YEAR MECHANICAL ENGINEERING, VCET,MADURAI.

INTRODUCTION Normally Mechanical energy of Actual Engine< Ideal Engine. Due to irreversible losses like heat lost in cooling medium. Thermal barrier coating on piston crown, valve heads and cylinder head causes 5-6% decrease in SFC, 4-5% increase in brake thermal efficiency and 8-9% increase in mechanical efficiency . This is proved from our experiment results.

COATING PROCESS SURFACE PREPARATION. a) VAPOUR DEGREASING. Cleanliness and Roughness. Solvents dissolve the contaminant Coating must be adherent to the surface.

THERMAL SPRAYING METHODS: WIRE FLAME SPRAYING. Temperature maintained with in 2600-3100 C. Velocity of the particle 90-100m/s. PLASMA ARC SPRAYING. Plasma arc gun to produce plasma. Plasma conduct current 2000A dc and voltage 30 to 80V.

COATING & MATERIAL PROPERTIES Higher density & Higher bond strength. Plasma arc torches for spraying refractory materials. Low thermal conductivity, high specific heat and high thermal strength.

Yttria stabilized Zirconia Co efficient of thermal expansion should be same order of magnitude as base structures. At cyclic temperature variation, coating materials adhere to metallic surface without interface stress. Maximum test life time correlates with non-equilibrium, non transformable tetragonal phase. Profound influence such as porosity, micro crack distribution are imparted.

MODE OF FAILURE MECHANISMS Oxidizing environment. Thermal expansion mismatch between ceramic and metallic layers. Actual failure occur within ceramic layer.

NO ENGINE DATA SPECIFICATIONS 1. TYPE KIRLOSKAR ENGINE 2. CYLINDER SINGLE 3. STROKE FOUR 4. SPEED 3000rpm 5. BORE DIAMETER 68mm 6. STROKE LENGTH 76mm 7. BHP 4.5 8. COMPRESSION RATIO 18:1 9. CAPACITY 553CC

MODE OF TEST GENERAL PRINCIPLES: Constant speed throughout the entire load, with sufficient number of runs. No data be taken until load, speed temperature have been stabilized.

WITHOUT COATING S.NO VOLTAGE (V) CURRENT (A) TIME FOR 10 CC FUEL(sec) 1. 220 2 53.5 2. 210 6 43 3. 10 37 4. 14 23

WITHOUT COATING NO BRAKE POWER KW SFC Kg/KWhr TFC Kg/hr BRAKE THERMAL EFFICIENCY % MECHANICAL EFFICIENCY 1. 0.491 0.98 0.57 7% 11% 2. 1.41 0.51 0.71 16.3% 26.2% 3. 2.35 0.35 0.82 23.5% 37.2% 4. 3.29 0.40 1.32 20.4% 47.8%

WITH COATING SNO VOLTAGE (V) CURRENT (A) TIME FOR 10 CC FUEL(sec) 1. 220 2 74 2. 210 6 57.5 3. 10 45 4. 14 36

WITH COATING NO BRAKE POWER KW SFC Kg/KWhr TFC Kg/hr BREAK THERMAL EFFICIENCY % MECHANICAL EFFICIENCY 1. 0.491 0.83 0.41 8% 15% 2. 1.41 0.38 0.53 22% 24% 3. 2.35 0.30 0.68 29% 47% 4. 3.29 0.24 0.84 35% 56%

CALCULATIONS BRAKE POWER: BP = (VI COSФ) / Transmission efficiency. (kW) WITH & WITHOUT COATING BP = (210*6*0.95) / 0.85. BP=1.41Kw SFC = TFC / BP .kg / kW hr WITHOUT COATING SFC=0.71/1.41. SFC=0.51 kg / kW hr WITH COATING SFC=0.53/1.41 SFC=0.38 kg / kW hr

T.F.C: T.F.C = (10*3600*S.G) / (t*1000).(kg/hr) WITHOUT COATING TFC = (10*3600*0.845) / (43*1000). TFC = 0.707 Kg/hr. WITH COATING T F C = (10*3600*0.845 / (57.5*1000). TFC = 0.53 Kg/hr. BRAKE THERMAL EFFICIENCY BTE = (BP*100) / (Mf*C.V). Mf =T.F.C / 3600. BTE = (1.41*100) / (1.96*4.4). BTE = 16.3% BTE = (1.41*100) / (1.47*4.4). BTE = 21.79%

GRAPH: All specific fuel consumption are based on observed brake horsepower . Brake power Vs Total fuel consumption. Brake power Vs Specific fuel consumption. Brake power Vs Mechanical Efficiency. Brake power Vs Brake Efficiency.

PRACTICAL BENEFITS: DECREASE IN FUEL CONSUMPTION: The heat dissipated to the medium influences the fuel cost. Ceramic coating insulates the combustion zone components. Thermal energy, normally lost in the cooling medium and exhaust gas, is converted to useful power using turbo machinery.

EXHAUST EMISSION CONTROL: Time between start of fuel injection and its ignition, is reduced and there is large drop in the height of combustion spikes. As a result unburned hydrocarbon emissions, more complete oxidation of soot, and reduced exhaust smoke.

CONCLUSION Problem solving technology. Improve product and performance, reduce maintenance time, cost, save energy and reduce production cost. Improvements in the performance, fuel versatility, operating life and maintenance requirements of medium.

REFERENCES 1. Wong.T.Y.Scott, G.C, and Ripple, E.D, 1993, “Diesel Engine scuffing: A preliminary investigation”. 2. John.B.Heywood, 1998, Internal Combustion Engine Fundamentals 3. Motor India, “High Efficiency Diesel Engine with Ceramic components”, Manual1986.

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