LHR Engine Research Articles

Reducing NOx emissions in biodiesel-powered LHR engines using an antioxidant additive: a methodological approach

This study examined the effects of various biodiesel blends with an antioxidant additive on the performance and emissions of a 5.2 kW diesel engine, coated with lanthanum oxide to enhance its performance. The aim was to identify the optimal blend and proportion of biodiesel and antioxidant that could reduce NOx emissions while maintaining or improving engine performance. Experiments were conducted on low heat rejection and conventional engines, using different blends of AME, WCOME, and JME with different proportions of L-ascorbic acid and LA. Results showed that a 20% biodiesel blend with 200 mg of LA additive performed best in a low heat rejection engine, with a 15.8%, 10.4%, and 9.3% reduction in HC, CO, and smoke emissions, respectively, compared to diesel. The NOx emissions increased by 13.7% with biodiesel blends, but AME20 exhibited the lowest increase of only 2.1%. Additionally, AME20 showed the highest brake thermal efficiency (BTE) of 30.3% and the lowest HC, CO, and smoke emissions among all the blends. Further experiments revealed that adding LA200 mg to a 20% blend of biodiesel in a low heat rejection engine resulted in even more significant improvements.

Assessment of Performance and Emission Characteristics using Algae Biodiesel in an Additive Fuelled LHR Engine

Automobiles use compression-ignition (CI) engines because they have more pulling power, are more dependable and use less fuel than spark-ignition (SI) engines. Both CI and SI engines use petroleum-based oils, contributing to environmental pollution like acid rain, ozone depletion and climate change. The cost of petroleum-based fuel is increasing daily due to demographic growth and the development of manufacturing industries. There are four phases to the experiments. The first stage involves mixing diesel with 20% of ALME, the outcomes showed that engine operation and combustion are comparable to conventional diesel fuel. In the second stage, an LHR engine tests 20% of ALME and the results showed that BTE of LHR engine had significantly increased. In comparison, NOx increases in LHR-operated CI engine, CO, HC and smoke emissions are significantly lower than with a conventional engine. The third stage looks at how NA interacts with biodiesel to affect conventional engine’s combustion, emission and engine performance. The prepared algae biodiesel is blended with NA in various ratios of 500ppm, 1000ppm, 1500ppm and 2000ppm. At 1000ppm concentration, NOx emission from conventional and LHR engines has been effectively minimized under load conditions. Concerning diesel fuel, emissions like CO, HC and smoke are significantly reduced for all loads. In the fourth stage, tests on the LHR engine are carried out using the SBME with NA in various proportions. When compared to base fuel, it has been found that NOx emission has decreased significantly at 1000ppm compared to conventional engines and other emissions have decreased.

Effects of Thermal Barrier Coated Piston on Performance and Combustion Characteristics in Dual-Fuel Common-Rail Diesel Engine

In this study, performance and combustion characteristics of biogas and biogas+hydrogen mixtures were experimentally analysed and compared with baseline diesel fuel in a common-rail diesel engine with and without thermal barrier coated piston. Tests were conducted at three different loads (50 Nm, 75 Nm, and 100 Nm) and a constant speed of 1750 min-1. Engine pistons were coated with Yttria Stabilized Zirconia by atmospheric plasma spray method. Results showed that by replacing the standard pistons with the coated pistons, an increase for diesel, biogas, and hydrogen enriched biogas was respectively defined by 8.1%, 6%, and 23% in cylinder pressure, and 19.8%, 12.6%, and 25% in HRR at medium load. Similarly, there was an increase in range of 1.05-12.8% in gas temperature and 20.5-117.2% in knock intensity by the piston coating. CA10-90 was prolonged between 1-15 oCA with gaseous fuel modes and increased with the engine load. Volumetric efficiency was reduced by 0.1-4% with the gaseous fuel operations, while it was increased by using the coated piston for all fuels. Exhaust gas temperature increased with the gaseous fuels whereas showed discrepancies with the coated piston engine. Dual-fuel mode and coated pis-ton application caused brake specific energy consumption to increase significantly.

Assessment of the performance combustion and emission characteristics of a biodiesel with natural additive in a low heat rejection engine

The use of petroleum-based fuel is increasing daily due to population growth and the expansion of manufacturing industries. Researchers must develop alternative fuels to meet the current fuel demand. The natural additive (NA) esters and pyrolytic oil from Sterculia foetida seeds were used in this study. Initially, diesel is combined with Sterculia foetida oil-methyl ester (SFME) and Sterculia foetida oil-pyrolysis in a 20% ratio. Further, testing of 20% of Sterculia foetida Methyl ester (SFME) and pyrolytic oil was performed in an LHR engine. The findings showed that LHR engines’ fuel usage and BTE had improved significantly. Emissions like CO, HC, and smoke are significantly lowered concerning diesel fuel at all loads. Finally, conventional and LHR engines were evaluated, resulting in an improvement in BTE of 2.5%. BSFC has decreased by approximately 12%, and NOx has decreased to a limit of 12% for SFME.

Investigation of ceramic coating on operating characteristic of DI CI diesel engine fuelled with safflower methyl ester

As reliance on fossil fuel continued to rise, prices increased due to rapid deterioration in oil supplies and increased emissions, green energy sources such as alternative renewable fuels have been promoted. Biofuel is a compression ignition fuel substitute; It is also possible to enhance the CI biofuel-based engine's performance by transforming it into a low heat rejection engine (LHR). A CI engine's thermal efficiency can be improved with the LHR engine by reducing heat loss to the environment. In this investigation, a ceramic material (Partial Stabilized Zirconium) of approximately 0.5 mm was coated by the plasma spraying on piston crown.The effects of safflower methyl ester (SAME) in the LHR engine along with retarded timing (RT) is compared with the standard one engine in the present work. The results show that the LHR engine's Brake thermal efficiency was more than the standard one. The emission levels of CO and UBHC are lower on the LHR engine compared to the standard one.

The Effect of Thermal Barrier Coatings on Diesel Engine Performance

The performance of internal combustion engines should be improved depending on some technological requirements and rapid increase in the fuel expenses. On the other hand, the improvements in engine materials are forced by using alternative fuels and environmental requirements. Therefore, the performances of engine materials become increasingly important. For improving the performance of engine, thermal barrier coatings (TBCs) are a promising step forward. In this experimental study, alumina – (40 %) titania and nickel - chromium are used as the thermal barrier materials. The purpose of using these materials is to reduce the heat loss from engine. TBCs are done by atmospheric plasma spraying technique. Engine working conditions are maintained constant before and after coating. The results showed a reduction in specific fuel consumption. CO and HC emissions are slightly more than the conventional coated diesel engine at low and medium loads but lesser at higher loads whereas NOx is reduced. Keywords: YSZ; TBC; LHR engines; Diesel engine

Effects of partially stabilized zirconia fueled with Borassus biofuel at different piston bowl geometries in LHR engine

Effects of partially stabilized zirconia fueled with Borassus biofuel at different piston bowl geometries in LHR engine

Addition of diethyl ether on the LHR engine characteristics using biodiesel-eucalyptus blend

ABSTRACT The present experiment deals with the study of addition of diethyl ether on the performance and emission characteristics of LHR engine using papaya methyl ester-eucalyptus oil blends. The test blends are CPME30Eu70 (Carica papaya methyl ester 30% and Eucalyptus oil 70%), CPME30Eu70 + 10% DEE and diesel. The optimum results we get with presence of DEE in CPME30Eu70 in LHR engine. The presence of DEE creates a lean mixture, low viscosity, high cetane number and volatility improves performance for a large degree. The graph depicts that addition of 10% diethyl ether gives the best performance in BSEC, BSFC, BTE and emission wise when coupled with LHR engine. At higher load, BTE for CPME30Eu70 added with 10% in coated engine is 33% and it was 3% higher compared to CPME30Eu70 in uncoated engine. Most notably NOx emission rate is decreased by the presence of the DEE and BSFC is brought under acceptable limit. NOx emission rate while using diethyl ether decreased the emission by 90 ppm when compared to blend without diethyl ether. BSEC decreases in CPME30Eu70 + 10%DEE and betters the performance of diesel in conventional engine. It also said to improve the cold flow properties of the CPME-eucalyptus oil blend.

Effect of ceramic coating on the performance, emission, and combustion characteristics of ethanol DI diesel engine

Ethanol and vegetable oils played an important role for more than 70 years in many countries all over the world. Since 19th century, ethanol has been used as fuel for Compression Ignition (CI) engines. By fermenting and distilling the biomasses, ethanol can be obtained and hence it can be considered as a renewable fuel. One way of increasing the efficiency of the ethanol fuel CI engine is to use it as a Low Heat Rejection Engine (LHR). In LHR engine, the thermal efficiency of the CI engine can be increased by reducing the heat loss to the surroundings through coolant and exhaust gas. The heat can be transferred from the combustion chamber to the piston, cylinder wall and finally to the cooling water. The heat transfer can be minimized by insulating the piston and cylinder wall and coating the piston and the cylinder wall with ceramics, which can withstand high thermal stresses. The coating materials have low thermal conductivity, thus reducing the heat flux into the piston and thus the heat transfer to the coolant is reduced. In the present work, Zirconia is used for coating the engine components for lower thermal conductivity. It is concluded that sole ethanol as fuel with glow plug show a reduction in exhaust emissions with reduced efficiency compared with conventional CI engine operated with diesel fuel. But it was observed that, there is a slight increase in thermal efficiency of the engine with the retarded injection timing. Converting a conventional engine to low heat rejection diesel engine further increases the thermal efficiency and reduces the carbon monoxide and unburned hydrocarbon emissions drastically, whereas oxides of nitrogen emission are increased because of higher combustion temperature.

A review on thermal barrier coating for diesel engine and its characteristics studies

Thermal Barrier Coating (TBC) on diesel engine performance was studied with a purpose of improving the thermal efficiency by decreasing Specific fuel consumption (SFC) and reducing exhaust emissions. This review paper gives a comparison of a standard diesel engine over a Low heat rejection engine. The experimental results from the various researchers show a gradual improvement in efficiency and specific fuel consumption rate. Higher operating temperature in combustion chamber gives higher efficiency which by using temperature resistant materials. Yttria-stabilized zirconia (YSZ) ceramic, ZrO2, Al2O3, Aluminium titanium are the coatings used on piston crown, cylinder liners, valves by adopting plasma spray technique. The results of LHR engine shows that, NOx emission is increased, whereas the efficiency and SFC are closer to standard engines at Low loads and noticeable improvements are seen at higher loads.

Turbocharging in ceramic coated engines using Rankine cycle for automotive use – An inceptive study

In an ordinary internal combustion engine only one third of the total heat liberated by the combustion of fuel is converted in to useful work. The exhaust gases leaving the engine are generally at a high temperature and hence they carry away a good amount energy. Substantial amount of energy is rejected via heat through the cooling system. An improvement in fuel economy could be seen, if the rejected energy to the coolant system could be used. LHR engines are the one in which the walls of the combustion chambers are coated with ceramic materials so that the heat loss to the coolant is very much reduced. It is thought that due to the adiabatic nature of the combustion chamber walls the energy available inside the cylinder for conversion in to useful work is more and this will improve the efficiency of the engine. But it is a well-known fact that only a marginal increase in the thermal efficiency of the engine is noticed. The reduction of heat loss from the combustion chamber of diesel engines improves fuel efficiency only by 3 or 4 per cent. The major amount of energy goes with the exhaust gasses as the gasses leave the engine at a very high temperature. For more than a decade, many researchers have pursued the implementation of thermal barrier coatings (TBCs) in diesel engines to increase the combustion temperature and to increase the engine performance. In this work a novel method of recovering energy from the exhaust and to improve the overall efficiency of the engine is presented. The effect of thermal barrier coatings on diesel engine energy balance system is studied. Improving the performance of the engine by recovering heat from exhaust with Rankine cycle is investigated.

Evaluation of Performance and Emissions of Ceramic Coated Turbocharged Direct Injection Diesel Engine operated with Diesel and Biodiesel Blends

It is evident that the main derivatives of biodiesel obtained from the transesterification of vegetable oils are identified as a best suitable alternate fuel for conventional diesel fuel. However higher viscosity and poor volatility of biodiesel causes engine problems for long-term use in diesel engines. Preheating of biodiesel is one of the technique reducing the problems associated with the higher viscosity of biodiesel in diesel engines. The positive effect of increased operating temperature of ceramic-coated engine concept is incorporated to avoid the preheating and maximize the effective heat release of biodiesel. The combination of increased operating temperature associated with LHR engine and oxygenated nature of biodiesel ensure nearly complete combustion. The experiment was conducted on a four cylinder four stroke direct injection turbocharged diesel engine and the combustion chamber was coated with partially stabilized zirconia (PSZ) of 0.35 mm thickness over 0.15 mm thickness of NiCrAl bond coat. The performance and emissions of conventional turbocharged engine and ceramic coated turbocharged engine were analyzed using diesel and biodiesel blends.

Experimental Analysis of Low Heat Rejection Engine Powered by Blends of Waste Plastic Oil and Diesel

The energy consumption throughout the world has been increasing every day. The fossil fuels are the main energy source for automobiles. The increase in the usage rate of fossil fuel proves to be a major source of greenhouse gases and air pollution. On the other hand, in the form of waste plastic, a good source of energy is dumped without any usage. Since plastic materials are non-degradable, this leads to a considerable problem in solid waste management. Waste plastic oil can be obtained through pyrolysis process of waste plastic. The physical and thermal properties of the waste plastic oil (WPO) are near to the diesel fuel. The waste plastic oil can be directly used as a fuel for unmodified CI engine. This reduces plastic waste, and it acts as a viable source of energy. In this experiment, different blends such as WPO20, WPO40, WPO60, WPO80 and neat waste plastic oil are used as a fuel in the CI engine. The performance and emission results have shown that WPO20 produces better results than the other blends of waste plastic oil. So, this blend is used for further research. Many researchers have analysed the engine characteristics using WPO as a sole fuel in CI engine, but no research has been done so far with WPO as a fuel in LHR engine. LHR engines have various advantages such that they may increase the adiabatic flame temperature, reduce the heat loss, which in turn increases the brake thermal efficiency, and reduce HC and CO emissions. The LHR engine is tested with WPO20 as a fuel, and its performance and emission values are compared with a conventional diesel fuel engine. The engine vibration is found to be reduced while using LHR engine rather than the conventional diesel fuel engine. The experiment results from LHR engine show improved BTE and reduced emissions, such as CO and UBHC, while there is a slight increase in NOx.

Performance and Emission Characteristics of Biodiesel-Butanol Blended Fuel in Lhr Engine

Performance and Emission Characteristics of Biodiesel-Butanol Blended Fuel in Lhr Engine

Research on energy distributions of the lateral swirl combustion system in DI diesel engines

The lateral swirl combustion system (LSCS) can improve the air-use, fuel and emission performance of direct injection (DI) diesel engines. In this study, the differences in energy distributions between the LSCS and the double swirl combustion system (DSCS) were analyzed under different working conditions using a single-cylinder test system. A simulation calculation was used to compare the velocity, mixture equivalence ratio and in-cylinder temperature distributions of the working medium in the two combustion chambers, elucidating the different energy distributions of the two chambers. Additionally, a new idea is proposed herein for the design of LHR engines. The experimental results show that, compared with the DSCS under different operating speeds (1300–2100 r/min) and different loads (21–43 kW), the indicated thermal efficiency of the LSCS was approximately 2% higher, the percentage of the exhaust energy and heat transfer to the total energy was approximately 2% lower, the cylinder head temperature was 2–20.5 K lower, the ratio of the cylinder head heat transfer to the total heat transfer was 2–8% smaller and the heat transferred to the cooling water in the water jacket of the cylinder head was 0.2–1 kW lower. The in-cylinder velocity distribution, mixture equivalence ratio and temperature distribution of both the LSCS and the DSCS were compared through simulation. The results show that the fuel in the LSCS developed along the wall of the combustion chamber circumferentially due to the convex edge, and the high temperature zone distributed along the circumference of the combustion chamber. In the DSCS, most of the fuel moved to the cylinder head due to the circular ridge, and the high temperature zone existed near the cylinder head. The LSCS had a lower cylinder head temperature, a higher exhaust gas temperature, and less heat transferred to the cooling water through the cylinder head. Therefore, the unique shape of the LSCS chamber guided the movement of the fuel and reduced the concentration of the fuel/air mixture near the cylinder head, which reduced the heat transferred to the cooling system through the cylinder head and improved the thermal efficiency. In addition to these findings, this study also provides a foundation for the design of a low heat rejection engine.

The experimental investigation on performance and emission characteristics of ceramic coated diesel engine using diesel and biodiesel

In this study, the effect of diesel and biodiesel (Sesame oil methyl ester) blends on performance and exhaust emissions of a single cylinder, ceramic coated diesel engine were investigated. In this work, the piston crown and outer surface of the cylinder liner of a diesel engine was coated with the ceramic material Aluminum Titanate by plasma spray technique. Thus, a thermal barrier was provided to the parts of combustion chamber with this ceramic coating. Ceramic coatings applied to the combustion chamber of diesel engine are preferred to reduce the transfer of heat from the combustion chamber to the cooling system. The biodiesel (Sesame oil methyl ester) was initially prepared from sesame oil by transesterfication process. Then, it is blended with diesel to a suitable proportion of 10% and 20% by volume. In this investigation, the brake thermal efficiency for diesel in ceramic coated engine was found to be higher than the conventional diesel engine. The efficiency was improved by 1.77% compared to conventional diesel engine. The emissions like carbon monoxide and hydrocarbon except oxides of nitrogen were decreased due to complete combustion of the fuel in the thermally insulated combustion chamber of the LHR engine.NOX was found to be higher for LHR engine with diesel and biodiesel blends due to higher in-cylinder gas temperature as compared to the conventional diesel engine using diesel fuel.

Experimental Investigations on LHR Single Cylinder Air Cooled Diesel Engine using Simarouba Biodiesel and its Blends as Alternate to Diesel Fuel

Experiments are conducted to study the performance, exhaust emissions and combustion characteristics of a conventional and LHR diesel engine running with simarouba biodiesel (100%) and its blends (10, 20 and 30% by volume) with diesel as an alternate fuel to neat diesel. The conventional engine is modified as LHR engine by coating 300 μm of PSZ on the piston crown which acts as thermal barrier and reduces heat loss to cooling medium and increases in-cylinder temperature by 50 to 100°C. Conventional and LHR engine are tested with neat diesel, biodiesel and biodiesel blends at an injection pressure of 200 bar and injection timing of 23° btdc. The load is applied in steps of 25% from no load to full load and results obtained are analyzed. LHR engine performed better compared to conventional engine; improved performance, significant reductions in exhaust emissions (except NOX) and improved combustion characteristics for all the blends tested. The percentage increase in brake thermal efficiency of neat diesel, SBD10, SBD20, SBD30 and SBD100 in LHR engine is 1.98, 5.61, 6.0, 3.98 and 2.98, respectively compared to conventional engine at 75% of full load. Amongst the blends tested, SBD20 proved to be better in both the engines. In LHR engine with SBD20 the percentage increase in brake thermal efficiency, pressure rise and heat release rates are 11.28, 6.35 and 14.0, respectively compared to diesel in conventional engine. Percentage decrease in carbon monoxide, hydrocarbon and smoke opacity is 50.0, 46.43 and 40.0, respectively as compared to diesel in conventional engine.

Experimental Investigation on Performance, Combustion and Emission Characteristics of a Low Heat Rejection Engine using Rapeseed Methyl Ester and Diethyl Ether

vBackground/objectives: Today, as a result of limited fuel resources and stringent emission standards, the methyl ester fuel has been focused on alternative fuels for I.C engine. Methyl ester fuels can be effectively used in low heat rejection engines (LHR), in which the surface temperature of the combustion temperature is increased by providing a thermal barrier coating. The main objective of our work is to reduce the engine exhaust emissions like HC and CO using diethyl ether in low heat rejection engine. Methods/Statistical Analysis: In this work, engine components like piston crown, cylinder head, and liner, inlet and exhaust valves of a diesel engine were coated with the ceramic material lanthanum zirconate by plasma spray technique. The effects of rapeseed methyl ester (biodiesel) produced by transesterification method and its blends with Diethyl ether (10% and 20% by volume) were studied in the low heat rejection engine. Findings: The thermal efficiency is found to be higher for diesel and biodiesel in the LHR engine. The results indicate that, B10 (10% Diethyl ether & 90% Biodiesel) and B20 (20% Diethyl ether & 80% Biodiesel) shows lower thermal efficiency compared with that straight biodiesel in low heat rejection engine. Applications/Improvements: Significant improvements were observed in engine exhaust emissions like CO and HC (except NOx) for all the diethyl ether blended biodiesel fuel in LHR engine. The higher oxygen content in the blended fuel reduces CO and HC emissions by 10% and 18% respectively compared to biodiesel in LHR engine.

Performance, emission and combustion characteristics of a semi-adiabatic diesel engine using cotton seed and neem kernel oil methyl esters

The performance, emission and combustion characteristics of a diesel engine are investigated using two methyl esters: One obtained from cotton seed oil and other from neem kernel oil. These two oils are transesterified using methanol and alkaline catalyst to produce the cotton seed oil methyl ester (CSOME) and neem kernel oil methyl ester (NKOME) respectively. These biodiesels are used as alternative fuels in low heat rejection engine (LHR), in which the combustion chamber temperature is increased by thermal barrier coating on piston face. Experimental investigations are conducted with CSOME and NKOME in a single cylinder, four stroke, direct injection LHR engine. It is found that, at peak load the brake thermal efficiency is lower by 5.91% and 7.07% and BSFC is higher by 28.57% and 10.71% for CSOME and NKOME in LHR engine, respectively when compared with conventional diesel fuel used in normal engine. It is also seen that there is an increase in NOx emission in LHR engine along with slight increase in CO, smoke and HC emissions. From the combustion characteristics, it is found that the values of cylinder pressure for CSOME and NKOME in LHR engine are near to the diesel fuel in normal engine.

Influence of Nano Coating on an Exhaust Valve of a Thermal Barrier Coated, Bio-Diesel Fueled CI Engine

The goal of this venture is to design and develop exhaust valve for diesel engine with increased material composition to lower failure on automotive applications. Exhaust valve of internal combustion engines exhaust price performs a crucial role to expel the burned gases out. Nevertheless prolong utilization of this valves will introduce thermal stresses and ultimately reduces its durability. Design of these values also is dependent upon many parameters, like fluid dynamics of exhaust fuel, fatigue strength of valve fabric, oxidization characteristics of valve fabric and exhaust gas, leakage, again pressure, habits of material at excessive temperature, the configuration of the cylinder head, the coolant waft, the form of the exhaust port, and many others. On this work the greatest design and progress of a brand new exhaust valve for Bio-diesel fuelled LHR engine by way of considering that above acknowledged parameters has been applied to beef up the efficiency of the engine. The excessive temperature exhaust gasoline influences the valve material properties and reduces the durability.