Industrial Project At

Central Railway’s Locomotive workshop, Parel

Under the guidance : Prof. uthale suhas

Carried Out By :

Vivek Venkataraman Abhishek Singh Chinmay Patil

Project Title :

“Design analysis of Diesel Locomotive engine with & without thermal barrier coating”

Objective :

To increase the power output/Horse power (HP) & efficiency of diesel locomotive

engine.

To reduce fuel & lube oil consumption and to increase the thermal efficiency of the

engine.

To reduce the NOx, particulate, CO & black smoke emissions.

Detailed

study &

observation of the locomotive engin

es.

Design & modificat

ion of the

various elements in order

to increase

the Horse Power

(HP) & to increase

fuel efficienc

y.

Analysing

using modell

ing softwa

re’s like

Solidworks,

abaqus &

ANSYS.

Final Project report on the design consideration

s, modifications

& analysis done.

Project Flow Process :

Literature study & understanding of the diesel engine & its components.

Thermal barrier coating of various engine components to increase their duty cycle, increase in better fuel combustion, reduce fuel &lube consumption.

Detailed analysis of thermal barrier coating on various engine components & careful observation of its effects, so as to make the necessary modifications & design considerations

Project Procedure :

Introduction :

Thermal barrier coatings consist of four layers: the metal substrate, metallic bond coat, thermally grown oxide, and ceramic topcoat.

The ceramic topcoat is typically composed of yttria-stabilized zirconia (YSZ) which is desirable for having very low conductivity while remaining stable at nominal operating temperatures.

The oxide that is commonly used is Zirconia oxide (ZrO2) and Yttrium oxide (Y2O3). The metallic bond coat is an oxidation/hot corrosion resistant layer. The bond coat is empherically represented as MCrAlY alloy where

M - Metals like Ni, Co or Fe. Y - Reactive metals like Yttrium. CrAl - base metal.

This ceramic layer creates the largest thermal gradient of the TBC and keeps the lower layers at a lower temperature than the surface.

Thermal barrier coating consisting of metallic bond coat on the substrate and ceramic top coat on the bond coat.

Project Challenges :

To search a proper bond coatings and top coat materials based on composition of substrates.

Selection of proper coatings techniques.

Preparation of plasma sprayed coated samples for various tests.

To check the microstructure and Topology of coating.

To check the surface texture parameter of coating.

To determine the bond strength of coating.

To determine micro hardness of coating.

To determine abrasive wear of coating .

To determine erosion wear of coating.

To establish the suitability of coatings for its application in internal combustion Engine as a linear.

Literature Survey :

Thermal barrier coatings are highly advanced material systems usually applied to metallic surfaces, operating at elevated temperatures, as a form of Exhaust Heat Management.

These coatings serve to insulate components from large and prolonged heat loads by utilizing thermally insulating materials which can sustain an appreciable temperature difference between the load bearing alloys and the coating surface.

In doing so, these coatings can allow for higher operating temperatures while limiting the thermal exposure of structural components like piston, connecting rods etc in case of diesel engines & also extending part life by reducing oxidation and thermal fatigue.

In conjunction with active film cooling, TBCs permit working fluid temperatures higher than the melting point of the metal.

Exhaust gas temperature changing between 400-600 0C for conventional diesel engines while it is between 700-900 0C for thermal barrier coated engine

Thermal Efficiency for Baseline and Ceramic Coated Engines

Ceramic Process- Reactive

Infiltration5µm

ab

Fig .NiAl Al2O3 composite.

• Dark phase is ceramic.

Alternate Ceramic Process- Reactive Infiltration

Established Processing Scheme

SiO2 shaped precursor is immersed in liquid Al at 1100 degree C.

4Al+3SiO2 --> 2Al2O3+3Si

As 2 moles of Al2O3 are smaller than

3 moles of SiO2, porous alumina created and infiltrated!

Enhancements in this program

Use high melting metal or intermetallic tofill pores in ceramic instead of aluminum.

Add continuous ceramic fibers as well.

DESIGN MATERIAL REQUIREMENT FOR TBC

•Some of the innumerable design options with regard to TBC are given below.

Fuel Flexibility

Corrosion resistance

Availability and Reliability

Corrosion / Erosion resistance

Lower metal temperature

Lower transient thermal stress

Efficiency

Reduce coolant flow

Increase the turbine inlet temperature

Capital cost

Easily cast super alloy

Simplified cooling

BSFC as a Function of Speed for Baseline and Ceramic Coated Engines

PROPOSED APPROACH

Begin with models of Begin with models of Zirconia Oxideco(Z2O3)atings with Yttrium Oxide( Y2O3)coats and superalloy substrates which incorporate phase evolution, thermally growing oxide, and damage evolution.

Compare simulations of isothermal and thermocylic loading to existing experimental data.

Simulations of top coat materials with varying degrees of compliance and accounting for sintering and CMAS depositions.

Investigate alternative top coat materials and structures through materials design simulations.

To design an optimal set of residual stresses and crack compliances for improved coating performance and life.

Coatings with Zirconia Oxide(Z2O3)and superalloy substrates which incorporate phase evolution, thermally growing oxide, and damage evolution.

Compare simulations of isothermal and thermocylic loading to existing experimental data.

Simulations of top coat materials with varying degrees of compliance and accounting for sintering and CMAS depositions.

Investigate alternative top coat materials and structures through materials design simulations.

To design an optimal set of residual stresses and crack compliances for improved coating performance and life.

STUDY OF TBC IN PROGRESS

Some of the work related to Thermal Barrier Coating undergoing are

i. A study of solid-state reactions between the ceramic layer, the bond coat metal oxides, the bond coat and substrate.

ii. A study to determine the kinetics of phase transformation in the ZrO2-12Y2O3 system and the effect of such transformations on mechanical properties.

Detailed analysis of coating stresses and controlled process, plasma spray technology has significantly improved the reliability of TBC turbines, diesel engines and other heat engines.

Processing improvement in the control and development of TBC are required, further study on, the mechanisms controlling coating adherence and degradation in clean and dirty environments.

The effects of coating composition and structure on coating properties and correlation of models of engine tests are necessary to obtain thermal barrier coating that have even better tolerance to high temperature and thermo mechanical stresses.

ADVANTAGES OF THERMAL BARRIER COATINGS FOR DIESEL ENGINES

Using lower-quality fuels within a wider distillation range

Reduce Specific fuel consumption

Multi-Fuel capability

Faster vapourization & better mixing of fuel

Decrease knocking & noise caused during combustion

Ignition delay of fuel is reduced

Increased thermal & effective efficiency

Improvement occour at emissions

,

OTHER ADVATAGES OF TBC IN DIESEL ENGINES

Thermal Barrier Coatings developed primarily for turbine applications can also be used in diesel engines benefits derived from using this technology includes

An improvement in the diesel engine fuel economy.

Increase in engine power density.

40% heat reduction in in-cylinder heat rejection.

Reduction in the ring groove temperatures.

Reduction in the metal piston temperatures

Reduction in the lubricant temperatures

DISADVANTAGES OF TBC

The main disadvantage is ceramic bond coat interface region which was determined to be the weakest link in the ZrO2-12Y2O3 /NiCrAlYsystem.

Adhesive plus cohesive failure of the ceramic layer in this region occurred when the coating was subjected to a normal tensile load at room temperature as well as when applied on bars subjected to axial tension or compression at elevated temperature.

APLLICATIONS OF TBC

Thermal barrier coatings can also be applied on :furnace components

heat-treating equipments

chemical processing equipments

heat exchangers rocket motor nozzles

exhaust manifolds

jet engine parts and nuclear power plant components.

It has also been applied to uncoated blades used to drive the high-pressure hydrogen turbo pump of the

Space Shuttle Main Engine. Here the coating is applied to provide thermal lag.

Increase in Power to weight ratio & overall performance of the locomotive engine.

Increased fuel efficiency thereby control in diesel fuel expenditure.

Control & reduction in diesel emission like NOx which is a major concern.

Extended duty life cycle of engine components due to thermal barrier coating.

Reduction in consumption of lube oil & coolants due to thermal barrier coating.

Future Scope :

With insulating combustion chamber components, it is available to keep combustion temperatures high.

Due to high combustion temperatures thermal efficiency can be increased, exhaust emissions can be improved and fuel consumption can be decreased on diesel engines.

Ceramic materials which have low thermal conductivity and high thermal expansion coefficient are used for making combustion chamber components thermal insulated.

For a successful coating thermal coating, ceramic material has a high melting point, high oxygen resistance, high thermal expansion co efficient, high corrosion resistance, high strain tolerance, low thermal conductivity and phase stability.

CONCLUSION :

The End