Claims:The scope of the invention is defined by the following claims:

Claim:
1. The coated and uncoated engine components with thermal insulation were processed by plasma spray coating:
a. The energy from the arc is injected into plasma gas that in turn derives energy from the plasma stream. The power energy is degenerated as radiation and flows through the gun's cooling water
b. Plasma gas normally used nitrogen or argon that is doped with 12% hydrogen. The main component of the mixture is called as primary and the smallest as secondary gas. Neutral molecules are exposed to electron attack, which leads to their ionization.
c. The primary gas is used as the carrier gas and flow rate in operation is a significant factor. If high flow rate, powders can emerge from hottest part of the jet and a low flow rate cannot effectively transport the powder to the plasma jet.
2. As mentioned in the claim 1, Engine is allowed to run until it reaches a steady state. After, the load is gradually increased from idle to full.
3. As per the claim 1, aluminium titanate powder was injected to obtain the adhesion layer on the sandblasted substrate , Description:Field of Invention
The invention relates to the current analysis bargains the impact of Lanthana-doped Partially Stabilised Zirconia Thermal barrier ceramic coated on the exhibition, ignition and outflow qualities of LHR marine diesel engine. Plan of choice of these ceramic coating is to improvements on performance, combustion and emission reduction of the marine engine.
Background of the Invention
The CI marine engine is estimated to lose 30% of its energy through the coolant, the other 30% through the exhaust gases, and 5% through friction and other reasons. In view of these losses, the researchers developed low heat rejection engines in which some of the energy can be used more. The elements of the combustion chamber are coated by ceramic insulating materials and then called as low heat rejection marine engine (Taymaz. [2006], Energy, 31, 364-371). This concept is applied to a CI marine engine to minimize heat transfer and high combustion temperature is obtained.
The LHR engine raises the cylinder gas temperature by 200°C compared to traditional CI marine engine. US6177200B1 discloses high combustion temperature shortens the ignition delay time, so combustion starts early for proper mixing of air and fuel. The thermal barrier coating used in LHR marine engines not only increases temperature however decreases engine emission of CO, HC, smoke and particulates (B.R. Prasath et al. [2010], International journal of Thermal science, 49, 2483-2490). US 2005OO16512A1 discloses the sufficient amount of heat stored in the chamber reduces incomplete combustion and leads to reduced emissions of CO, HC, fumes and particles.
Combustion components have regularly been coated by thermal barrier layer for better engine performance and reduced pollutant emissions (Y. He et al. [2005], Renewable Energy, 30, 805-813). The ceramic coating of the combustion chamber hardware increased thermal efficiency by reducing heat emission. DICI engine fueled with Pongamia and diesel. The engine parts were coated with PSZ and lanthanum doped over a 350 and 150 µm thick NiCrAl tie layer. US6117560A stated that the specific brake fuel consumption for partially stabilized zirconium dioxide-Zirconate doped with lanthanum was reduced then diesel. In addition, CO and CO2 reduced and higher NOx emissions were noted from coated engine. Performance of internal combustion engines with combustion chamber hardware coated with ceramic materials, aluminum and titanium oxides in the plasma spray process. Both the engines were operated with a mixture of corn oil and diesel. EP0391950A1 says the reduced engine output, fuel consumption, smoke density, and CO emissions, as well as increased engine efficiency and NOx emissions compared to engines without liners. According to literature research, the main advantages of LHR engines are improved engine efficiency, reduced pollutant emissions, reduced fuel consumption, and removal of the engine cooling system. Diesel engines require a TBC coating to reduce the negative side of diesel in diesel engines
Advantages of LHR marine engines compared to CI marine engines are higher thermal efficiency, combustion, and lower emissions (H. Hazar, [2009], Renewable Energy, 34, 1533-1537). In addition, high wear ceramic materials used in LHR marine engines. These benefits far outweigh the problems posed by the fuels used in CI marine engines.
Summary of the Invention
In light of the above stated disadvantages, the current invention aims to improve the thermal efficiency, better combustion, performance and lower emissions by making the conventional marine diesel engine in to Lanthana-doped PSZ Thermal barrier ceramic coated Marine diesel engine.
The specific objective of the invention is to convert normal marine diesel engine to thermal barrier coated marine diesel engine by ceramic coating of hardware components of engine.
A further specific objective of the invention is to replace the diesel fuel in to alternate fuel in the marine diesel engine.
Brief Description of Drawings
The invention will be described in detail with reference to the exemplary embodiments shown in the figures wherein:
Figure 1 Experimental test rig of marine diesel engine components
Detailed Description of the Invention
Increasing the combustion temperature of a marine diesel engine increases efficiency and improves diesel emissions. Therefore, combustor parts must be made of highly heat resistant materials. One way to improve the strength of these elements at high temperatures is to coat them with a ceramic coating. Allowing higher combustion temperatures leads to better combustion and therefore improved fuel emissions. The coating also forms a thermal barrier to the heat transferred through the combustion chamber components. A small portion of the total energy from combustion is converted into energy useful in the combustion engine. More than half of this energy is dissipated from the system through the cooling system to protect engine components from overheating, friction, exhaust fumes and other losses. The most effective way to increase the useful work of the engine is to reduce the losses mentioned above.
Globally inventors have tried to increase engine power by switching to LHR engine mode. Materials such as partially stabilized zirconium oxide, yttrium oxide stabilized zirconium oxide, calcium zirconite oxide, aluminum oxide, aluminum titanate and mullite are used to coat internal combustion engine components. Of these coating materials, partially stabilized zirconia with a lantern dope was found to perform well in the use of diesel. Zirconia is mixed with a metal oxide of MgO or Y2O3 to form a cubic structure at various temperatures. Cubic stabilized zirconia is a valuable ceramic material that does not undergo a destructive phase change during heating and cooling. In this invention, magnesia to be mixed with zirconium is selected based on its availability and cost. Zirconia is mixed with 10% MgO and is called PSZ. PSZ is often used as a TBC material due to its low thermal conductivity and phase stability at operating temperatures above 1200°C. Doping a small amount of lanthanum oxide with PSZ improves the quality of the coating, as the addition of 10% MgO increases the sintering tendency. This reduces thermal conductivity and sintering resistance. Therefore, in this study, PSZ with lanthanum oxide added was selected as the coating material. The engine components were coated using a plasma spray process. This method is ideal, accurate and effective
Atmospheric plasma spraying is commonly used thermal spraying processes and has many uses due to the variety of thermal spraying of various materials, from metal to non-metal, for the following thermal spraying materials: It is suitable. Nowadays, almost any substrate can be used with any material for plasma spraying. Process parameters have a significant effect on formation of microstructures, the adhesion of the coating to the substrate, and the mechanical strength of the coating.
The plasma spray process consists of powdered material filled along a high temperature plasma fire, there it heats rapidly and accelerates the method. This impact of the hot material on the surface of the substrate cools quickly and immediately begins to frame the coating. The plasma gun contains a copper and tungsten act as a anode and cathode, both of which are water-cooled. The plasma gas flows through the cathode and anode and form a nozzle. This plasma spray process uses argon as the carrier gas and hydrogen as the make-up gas.
Cylinder head, cylinder liner, piston crown, exhaust and inlet valves of the marine diesel engine were selected for the thermal barrier coating. First, the cylinder head was fixed in the holding chuck of spray booth. The distance between the tip of the gun and substrate surface was adjusted to fix at 120 mm. Then optimized operating parameters such as power, current and voltage was set to 20 kW, 500A and 65 V respectively. PSZ lanthana in the form of powder was injected at the flow rate of 10 g/min using argon as a carrier gas flowing at a rate of 10 l/min into very high temperature plasma flame, where it is rapidly heated and accelerated to a high velocity. The hot material impacts on the substrate surface and rapidly cools forming a coating. Similarly the second layer of coating was deposited over first layer.
The components of the CI engine were coated with PSZ lanthana doped to a thick of 350 µm on a 150 µm thick of Al2TiO5 layer by plasma spray process. Prier coating, surface must be sandblasted to obtain an external roughness of 4 µm, that is measured with the PCERT 11 roughness tester. It was then cleaned and dried in cold air. Aluminium titanate powder was injected to obtain the adhesion layer on the sandblasted substrate. Then this hot material combines the substrate and form a 100 µm thick layer. The next coating layer of PSZ with lanthanide having a thickness of 300 µm was made in the same way. Therefore, the total coating thickness is 500 µm.
3 Claims & 1 Figure