Diesel Engine Bench Test Research Articles

Potassium borate/graphene nanocomposite lubricant additive with anti-friction/wear and anti-corrosion functions for marine diesel engine burning low sulfur fuel

To suppress the corrosion and wear of cylinder liner of marine diesel engine burning low sulfur fuel, potassium borate/graphene lubricant additive was prepared by plasma assisted ball milling. Tribological tests were conducted by simulating operating condition of diesel engine to evaluate the anti-friction/wear and anti-corrosion properties of potassium borate/graphene additive. The effect of additive on cylinder liner corrosion and wear was verified by bench test of diesel engine. The results of tribological tests indicated tribochemical reaction occurred on the surface of the cylinder liner-piston ring and generated a tribochemical film composed of graphene, FeO, Fe2O3, Fe3O4, B2O3 and Fe2B with anti-friction/wear and anti-corrosion properties. Bench test shown that potassium borate/graphene additive had good anti-friction/wear and anti-corrosion functions, and reduced fuel consumption and exhaust emissions of the engine.

The effect of various urea-in-water solution types on exhaust particle number emission.

In order to qualitatively evaluate the impact of urea-in-water solution on the particle number emission, five different urea types were chosen under diesel engine bench test. The results show that compared to the instantaneous particle concentrations without injection, the instantaneous particle concentrations with injection increase distinctly, which are larger around 0.3-1.2 times than that without urea-in-water solution. At high speed phase, the instantaneous particle concentrations with urea-in-water solution injection rise obviously, especially for C and E solutions. In addition, the particle size distribution characteristic does not change with the urea-in-water solution dosing. The PN emission factors follow the sequence of C solution > E solution > A solution > B solution > D solution. It is deduced that the metallic element contents in the urea-in-water solution play a key role for the PN emission factor. In the future, the particle formation due to urea-in-water solution injection should be given more attention.

Comprehensive Experimental and Numerical Optimization of Diesel Engine Thermal Management Strategy for Emission Clarification and Carbon Dioxide Control

Improving the thermal efficiency of truck diesel engines requires comprehensive optimization of the engine, exhaust aftertreatment (EAT), and possible waste heat recovery (WHR). Lower exhaust temperature at mid and low working points has caused difficulty in both emission clarification and heat recovery, which requires thermal management. Based on the diesel engine bench test and separate bench tests, this paper focuses on the thermal management strategy optimization, to increase the exhaust temperature at lower working points and optimize the thermal efficiency of the whole system. The test and numerical analysis showed that as exhaust temperature increased from 200~250 °C to 300~350 °C, soot passive regeneration reactions were enhanced, nitrogen oxide emission decreased, and energy recovery was improved. Moderate throttle valve adjustment coupled with early post injection could effectively achieve the required temperature increase. The optimized thermal management strategy increased the fuel consumption rate by no more than 1%. Meanwhile, the WHR system output increased significantly, by 62.55% at a certain mid–low working point. System CO2 emission decreased by an average of 5.4% at selected working points.

Bench experimental research of cylinder oil on large marine diesel engines

To lower the risks of the real ship test of the cylinder oil of large marine low-speed two-stroke marine diesel engine, A 6S50ME marine diesel engine was selected to do bench test about cylinder oil. In the calibration condition, the test cylinder oil and the reference cylinder oil were compared. The test results show that the wear amount of cylinder liners, piston rings and piston-ring-grooves is consistent with the wear condition judged by the metal element content detected by the residual oil of the cylinder. At the same time, combined with the evaluation result of the detergency and dispersibility of the cylinder oil, it can effectively judge whether the oil product can be tested on the ship. Since wear volume of element Cr and Fe tends to the stabilization after 60 hours, so it is feasible to set the diesel engine bench test at 100 hours. In addition, special attention should be paid to the control of water outlet temperature and exhaust gas temperature in the test. The cylinder oil evaluated in the above way meets the requirements of OEM after the actual ship test. Thus, the assessment method of cylinder oil based on the bench test is feasible, and can greatly shorten the test time and reduce the test cost.

Effect of Lubricant Additives on the Oxidation Characteristics of Diesel Engine Particulate Matter

Three common lubricant additives, including an antioxidant, detergent, and an antifoamer, were added to diesel fuel to perform a diesel engine bench test. Particulate matter samples underwent thermogravimetric analysis to investigate the effect of lubricant additives on the particulate matter oxidation process, characteristic temperature, and activation energy. The results showed the following. Different lubricant additives result in different variation trends in the thermogravimetric curve of a particulate matter sample by varying the rotating speed and torque. When the rotating speed was stable, as the torque increased, the ignition temperature of the particulate matter of Fuel C declined rapidly during the initial stage and then increased rapidly. When the torque was stable, as the rotating speed increased, the ignition temperature of the particulate matter of Fuel C increased initially and then declined. The particulate matter of Fuel C had the lowest level of activation energy at approximately 57.89 J·mol−1. The particulate matter of Fuel A had the highest level of activation energy at approximately 74.10 J·mol−1. When the fuel has a higher cetane number, the combustion chemical reaction rate is faster and results in a more complete reaction. The active substance contact surface increases, which facilitates particulate matter oxidation.

Exhaust emissions of diesel engines with nano-copper additives

The effects of nano-copper additives were investigated through a thermogravimetric (TG) test, diesel engine bench test, and road driving test. The tests demonstrated that the nano-copper additive presented a good catalytic effect on the combustion of soot particles, which reduced the complete combustion temperature from 580 to 520 °C. The diesel engine bench test showed that particulate matter (PM), CO, and HC emissions were reduced by 99.9%, 81.30%, and 33.33%, respectively. The NOx emissions slightly increased due to the lack of carbon as a reducing substance in the exhaust gas. The road driving test with a diesel vehicle demonstrated that more stringent emission standards can be met without any upgrade to the engine.

Simulation of the flow field and the chemical reaction coupling of selective catalytic reduction (SCR) system using an orthogonal experiment.

It is difficult to simulate both the flow field and the chemical reaction using, respectively, the flow state and kinetics calculations and actually reflect the influence of the gas flow state on the chemical change in a selective catalytic reduction (SCR) system. In this study, the flow field and the chemical reaction were therefore coupled to simulate a full Cu-Zeolite SCR system and the boundary conditions of the simulation were set by a relevant diesel engine bench test which included the exhaust temperature, the mass flow, and the exhaust pressure. Then, the influence of the gas flow state on the NOx conversion efficiency was investigated. Specifically, an orthogonal experimental design was used to study the influence of the injection parameters (position, angle, and speed) on the NH3 distribution by establishing the NH3 uniformity coefficient γ at the SCR catalyst capture surface in the flow field simulation. Then, the velocity capture surface of the SCR catalyst front section was sliced into coupled data transfer interfaces to study the effects of exhaust temperature, ammonia to NOx ratio (ANR), and the NO2/NOx on the NOx conversion efficiency. This was used as guidelines to optimize the SCR system control strategy. The results showed that a 1150 mm injection position, a 45°injection angle, and a 23 m/s injection velocity provided the most uniform NH3 distribution on the SCR catalyst capture surface. For constant injection parameters, the NOx conversion efficiency was the highest when the exhaust temperature was 200°C—400°C, the ANR was 1.1, and NO2/NOx was 0.5.

Effects of phenolic antioxidants on biodiesel oxidative stability and emission

Biodiesel is a high‐quality diesel alternative fuel, but it can get easily oxidized on long‐term storage. The addition of antioxidants can effectively improve the oxidation stability of biodiesel. In this study, the mechanism of phenolic antioxidants to inhibit the oxidation of biodiesel and reduce the NOX emission is discussed based on the experimental investigation. Antioxidants (0.8 wt%) 3‐tert‐butyl‐4‐methoxyphenol (BHA), rosemary (K1), and tea polyphenols (K2) were added to biodiesel B100. The antioxidant test was carried out at atmospheric temperature for 4320 h, and the peroxide value, acid values were measured. Then, 0.8 wt% of K1, K2, and BHA were added to B20, named as K1B20, K2B20, and BHAB20. The 186F diesel engine bench test was carried out under 10%, 25%, 50%, 75%, and 100% load at 3000 rpm, with HC, CO, NOX, and smoke emissions of various types of fuel (B20, BHAB20, K1B20, and K2B20) were measured. The results of antioxidant test showed that the antioxidant effect of rosemary was best, displaying a decrease in acid and peroxide values by 25% and 48%, respectively. The diesel engine bench test results showed that antioxidants had little effect on HC, CO, and smoke emission; however, the antioxidants significantly reduced NOX emission. The effect of natural antioxidant rosemary to reduce NOX emission is the best one. At 3000 rpm and 75% load, the NOx of B20 reduced by 9.4%. Among the three antioxidants, the experimental results verified the mechanistic analysis and provided the basis for the selection of antioxidants for biodiesel. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019

STUDY OF THE OPERATION OF THE DIESEL ENGINE 4H 11,012,5 ON MIXTURES OF DIESEL FUEL WITH BIOGAS

One of the main tasks in the operation of automotive vehicles is the development of measures to protect the environment from toxic components of exhaust gases (exhaust) of internal combustion engines. Biogas is one of the most environmentally friendly fuels for vehicles, as it produces minimal emissions of carbon dioxide and particulate matter. The gas engine runs quieter, vibration is reduced, which helps to improve the working conditions of drivers. The article is devoted to the development of new fuel compositions based on diesel fuel (DT) and biogas (BG) that meet the requirements of their application in diesel. The article is referred to effective performance of a diesel and the performance of its opacity and toxicity when operating on mixtures consisting of 85% diesel + 15% HD and 70% diesel + 30% BG at different values of the angle of installation of an advancing of injection of fuel. The results of bench tests of diesel when working on these fuel compositions are given. Based on the analysis of the experimental data, the optimal regulation of the fuel supply equipment was determined. According to the results of bench tests of diesel engine with mixtures of BG following conclusions: 1) When using diesel fuels with the addition of 15% HD and 30% BG optimum installation angle of an advancing of injection should be considered ?vpr angle=22?; 2) Operation diesel with additives 15% HD and 30% BG, the amount of heat, allows to reduce the consumption of diesel fuel, respectively, 15% and 30%; 3) The diesel engine works on mixed fuels with the addition of the BG is accompanied by a reduction in emissions from the exhaust gases of soot particles tend to be around the expected range of variation of the angle setting; 4) Work on mixed diesel fuels with the addition of BG in the whole considered range of variation of the angle of installation is accompanied by an increase of emissions in the EXHAUST gas of nitrogen oxides and unburned hydrocarbons.

Ammonium-Salt Formation and Catalyst Deactivation in the SCR System for a Marine Diesel Engine

Due to the low temperature and complex composition of the exhaust gas of the marine diesel engine, the working requirements of the selective catalytic reduction (SCR) catalyst cannot be met directly. Moreover, ammonium sulfate, ammonium nitrate, and other ammonium deposits are formed at low temperatures, which block the surface or the pore channels of the SCR catalyst, thereby resulting in its reduction or even its loss of activity. Considering the difficulty of the marine diesel engine bench test and the limitation of the catalyst sample test, a one-dimensional simulation model of the SCR system was built in this paper. In addition, the deactivation reaction process of the ammonium salt in the SCR system and its influencing factors were studied. Based on the gas phase and the surface reaction kinetics, the models of the urea decomposition, the surface denitrification, the nitrate deactivation, and the sulfate deactivation were both constructed and verified in terms of accuracy. Moreover, the formation/decomposition reaction pathway and the catalytic deactivation of ammonium nitrate and ammonium bisulfate, as well as the composition concentration and the exhaust gas temperature range were correspondingly clarified. The results showed that within a certain range, the increase of the NO2/NOx ratio was conducive to the fast SCR reaction and the NH4NO3 formation’s reaction. Increasing the exhaust gas temperature also raised the NO2/NOx ratio, which was beneficial to both the fast SCR reaction and the NH4NO3 decomposition reaction, respectively. Furthermore, the influence of the SO2 concentration on the denitrification efficiency decreased with the increase of the exhaust gas temperature because of increasing SCR reaction rate and reversibility of ammonia sulfate formation, and when the temperature of the exhaust gas was higher than 350 °C, the activity of the catalyst was almost unaffected by ammonia sulfate.

Multisensor information integration for online wear condition monitoring of diesel engines

A diesel engine bench test was performed, and the online visual ferrograph (OLVF) and performance monitoring sensors were used to evaluate engine wear. The sliding window method was used to segment OLVF-monitoring data; features such as probability of smaller value and accumulated wear coefficient were extracted to clarify wear degree. The weighted combination multisensor information integration method was developed to calculate current engine condition factors. The results show that OLVF monitoring exhibits more sensitivity than other performance monitoring sensors. Using multisensor information provides an early warning of performance degradation ~40h before the diesel engine experiences a catastrophic fault.

Study on test instrument and filtration theory of the carbonized micron wood fiber DPF

In this paper, a method of utilizing the carbonized micron wood fiber (CMWF) as the filter material is presented and a corresponding numerical simulation method is applied. Furthermore, a kind of detachable diesel particulate filters (DPF) is developed, a diesel engine bench test is conducted and the influence elements upon Δ p/ H are researched. Theory and test show that the smaller the average micro pore diameter is, the larger the focal length of parabola is, which means that the numerical simulation method can be consistent with the test very well. Meanwhile, a lot of tests prove that the DPF filters with bigger pore diameter and longer length should take priority over the others, together with the increase of the filter length, the PM arresting efficiency will be improved and Δ p/ H also climbs up rapidly and a kind of modified CMWF DPF, of which the micro pore diameter reduces gradually from entry to exit end, possesses high filtration efficiency and low pressure drop and be suited to filter the exhaust gases of diesel.

Study on Flow Resistance and Filtration Efficiency of the Carbonized Micron Wood Fiber DPF

Airborne particulate matter is known for its environmental impact and is suspected of causing adverse health effects. Especially the role of ultrafine particles smaller than 0.1μm, which amongst others are emitted by diesel engines, is the subject of current health related discussions. In order to solve this problem, many filtration methods have been researched, while so far the results are unsatisfactory. In this paper, a method of utilizing the carbonized micron wood fiber (CMWF) as the filter material is presented and a corresponding numerical simulation method is applied. Furthermore, a kind of detachable DPF is developed, a diesel engine bench test is conducted and the influence elements upon Δp/H are researched. Theory and test prove that the numerical simulation method can be consistent with the test very well and the CMWF DPF has not only the low flow resistance and high efficient filtration but also very suitable for diesel exhaust gas purification.

Study on Friction Reduction and Anti-Scuffing Technology of Duplex Ion Nitrocarburizing and Sulphurizing

A new technology, duplex ion nitrocarburizing and sulphurizing technology (DINS), for friction reduction and anti-scuffing applications of diesel engine cylinder was studied. Duplex ion nitrocarburized-sulphurized layer was prepared on the surface of CrMoCu alloy cast iron by using the DINS process. The morphology, phase structure and tribological behaviors under sulphur contained additive lubrication were investigated. Results show that the sulphide surface layer of the duplex layer is mainly composed of close-packed hexagonal structured FeS phase and cubic structured FeS2 phase. The nitrocarburized sub-surface layer of the duplex layer is mainly composed of Fe2C and Fe3N phases. The harder nitrocarburized layer can provide effective support to the softer sulphide layer and avoid its lamellar tear. The synergistic effect between the duplex layer and the sulphur contained additive lubricant, resulted in 10% and 33.3% reduction in coefficient of friction and wear volume, respectively, compared with those of the sulphurized surface, and 25% and 50.1% reduction, respectively, compared with those of the plain surface. Bench test of diesel engine further demonstrated that the DINS process can provide the treated cylinder with superior properties in anti-scuffing and friction reduction, so that it can be used to prolong the service life of the cylinder.

Review of Ag/Al2O3-Reductant System in the Selective Catalytic Reduction of NO x

Ag/Al2O3 is a promising catalyst for the selective catalytic reduction (SCR) by hydrocarbons (HC) of NO x in both laboratory and diesel engine bench tests. New developments of the HC-SCR of NO x over a Ag/Al2O3 catalyst are reviewed, including the efficiencies and sulfur tolerances of different Ag/Al2O3-reductant systems for the SCR of NO x ; the low-temperature activity improvement of H2-assisted HC-SCR of NO x over Ag/Al2O3; and the application of a Ag/Al2O3-ethanol SCR system with a heavy-duty diesel engine. The discussions are focused on the reaction mechanisms of different Ag/Al2O3-reductant systems and H2-assisted HC-SCR of NO x over Ag/Al2O3. A SO2-resistant surface structure in situ synthesized on Ag/Al2O3 by using ethanol as a reductant is proposed based on the study of the sulfate formation. These results provide new insight into the design of a high-efficiency NO x reduction system. The diesel engine bench test results showed that a Ag/Al2O3-ethanol system is promising for catalytic cleaning of NO x in diesel exhaust.