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Investigations on the effect of H2 and HHO gas induction on brake thermal efficiency of dual-fuel CI engine
Abstract
Brake thermal efficiency is a vital performance characteristic of an IC engine. This research work focuses on evaluating the brake thermal efficiency of a commercial compression ignition engine used for irrigation and power generation. The dual fuel combustion strategies that used Hydrogen, HHO gases, and diesel. Hydrogen and HHO gas were induced into the intake manifold of engine at six different flow rates ranging from 6 to 36 L per minute. The engine was run with a maximum energy-share ratio of 86% with hydrogen and 70% with HHO gas, respectively. The efficiencies were calculated using the pressure trace obtained along with the four strokes. Under the proposed method, brake thermal efficiency was determined by summing up parameters including closed-cycle, open-cycle, and mechanical efficiency. It was noted that the closed-cycle efficiency of the engine was maximum at the ideal condition and reduced with the introduction of primary fuel. The maximum closed-cycle efficiency was 45% with neat diesel operation, and the minimums were 21.5% and 23% with 36 L per min of hydrogen and HHO gas supply, respectively. Because of the negative pumping mean effective pressure, the engine's open-cycle efficiency remained close to 90%. The engine's mechanical efficiency increased as the torque increased. The engine's performance can be improved by implementing different injection strategies that improves the closed-cycle efficiency.
... The increase in the EGR also creates an impact on the blend's in-cylinder pressure variation based on the ignition quality [30]. Due to the chemical kinetics during the EGR supply create the reduction in the pressure by increasing the EGR concentration in the inlet air with a reduced oxygen content which creates the dilution effect [19,31]. The instant increase in the pressure is because of the heterogenous mixture formation in the combustion [12,14,17,24]. ...
... The blending of the biodiesel has more delay period. This has a considerable impact on the heat release rate reduction [31,32]. Also, the EGR creates influence in the combustion which reduces the heat release rate [33] with the reduction in the cylinder pressure [34]. ...
... Smoke opacity is reduced by the EGR concentration increase and the blend of biodiesel increases because of the dilution effect [38,45,31,37]. These create an impact on the combustion through the increased viscosity of the fuel which reduces the vaporization of the fuel [46,47]. ...
Research on alternative fuel production and compression ignition (CI) engine improvement techniques is more attractive recently. Waste-to-wealth concept refers that the utilization of the waste of soapberry seed and exhaust gas to run the common rail direct fuel injection type diesel engine by optimizing their contribution through experimental analysis is the novelty of this investigation. The recirculation of exhaust gas plays important role in improving the combustion in the engine, reducing the emissions, and improving the engine performance. Soapberry seed oil methyl ester economizes diesel consumption by mixing it into diesel. Transesterification is the method used to turn soapberry seed oil into biodiesel. In the common rail direct injection (CRDI) engine, a 10%, 20%, or 30% blend of soapberry seed oil methyl ester (SSOB) with diesel is utilized as fuel. For each mix, 10%–30% of the volume of SSOB is added to the rest of the diesel. Along with these fuel types, exhaust gas recirculation (EGR) is used from 10% to 30% to test and optimize the best combinations for CRDI engines. The experimental results show that pure diesel with EGR recorded high heat release rate (HRR) and brake thermal efficiency (BTE) at the highest load possible. The maximum BTE of the tested tracks is 26.83% because of better combustion, which was achieved with 10% EGR and a combination of 30% SSOB and 70% Diesel. The increase in EGR such as 30% in 30% of SSOB with 70% of Diesel blend produced reduced NOx emission (865 ppm), smoke opacity (13%), and hydrocarbon (HC) emissions (10 ppm) than diesel fuel because of the dilution and chemical effects during combustion. Accordingly, the present research reveals that a 30% of soapberry seed oil methyl ester blend with 30% EGR is recommended for engine usage with lesser emission with better combustion and performance characteristics.
... This efficiency is described as the ratio of the amount of heat actually converted to the brake power to the total heat supplied or inverse product of brake specific fuel consumption and calorific value of the fuel (Tsutsumi et al., 2009;Venugopal et al., 2023). The variation of brake thermal efficiency (BTE) with respect to brake mean effective pressure (BMEP) is shown in Figure 3. ...
... The gas produced from the electrolysis of water including HHO gas known as Brown gas, Hydrogen-rich gas, Hydroxyl, water gas electrolysis of gas, etc [34]. The idea of reducing the risk associated with hydrogen storage is by producing on-site hydrogen thought water electrolysis which low space requires compared to other hydrogen production techniques [43]. This concept is similar to Alkaline water electrolysis, where both hydrogen and oxygen are generated at the cathode and anode, however, there is no separation of gas between the electrode and end products of gas, and this gas is known as HHO gas. ...
... The augmentation of engine performance can be achieved through the addition of fuel additives. Such additives may include hydrogen, nitrogen, ozone, HHO, etc [32][33][34][35].Hydrogen is a fuel that can be derived from renewable sources, including geothermal and solar energy [36,37]. The distinctive chemical properties of hydrogen, characterized by its high low heat value, flame speed, and broad flammability range, have been shown to enhance engine performance and increase engine efficiency. ...
... In the research of LDPE waste pyrolysis process, using magnesium bentonite catalyst at 340 °C temperature is maintained, with an average processing time of 200 minutes, 1% catalyst produces 77.97% cSt, and calorific value of 43.24 kJ/kg, no cetane 51.4, viscosity 2.86 cSt, physiochemical properties very similar to commercial diesel (Thangavel et al., 2023). The pyrolysis of plastics is mostly carried out with solid acid catalysts: zeolites (Hy, HZSM-5, HMordenite) and mesoporous MCM-41 (Jaroszewska et al., 2019;Chen et al., 2013;Zheng et al., 2018), Composite-MCM41/ZSM-5 (Ochoa et al., 2020;Yu et al., 2020), earthen pillared materials see, silica aluminate, oxides (CaO, ZnO, ZrO2) and activated carbon (Yu et al., 2020). ...
The widespread use of plastics has led to increased consumption of fossil fuels and worsened pollution, especially in oceans. Common waste management methods like landfills and incinerators often focus more on convenience than on environmental and economic sustainability. For example, incineration releases harmful gases such as carbon monoxide (CO), carbon dioxide (CO2), ammonia (NH3), nitrous oxide (N2O), and nitrogen oxides (NOX), significantly contributing to greenhouse gas emissions. Burning one ton of waste can produce at least 700 kg of CO2. This study explores the use of Titanium Dioxide (TiO2), derived from minerals like ilmenite, rutile, and anatase, to enhance the pyrolysis process of Low-Density Polyethylene (LDPE) plastic waste. TiO2 helps stabilize heterogeneous catalysts and can improve the efficiency of plastic degradation, reduce the necessary temperatures, and shift the output from more liquid to more gas, with properties similar to commercial gasoline. The research tested different temperatures (300 °C, 350 °C, 400 °C, 450 °C) and catalyst amounts (12.5 g, 25 g, 37.5 g) to transform LDPE waste into liquid fuel. The best results were achieved at 350 °C with 37.5 g of catalyst, producing a fuel with a density of 0.7660 g/ml, viscosity of 1.04 mm2/s, calorific value of 36.1698 MJ/kg, and a flash point of 34 °C. Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that the fuel consisted of 49.41% gasoline, 10.56% kerosene-diesel, and 40.03% fatty acids. The findings indicate that using TiO2 as a catalyst in pyrolysis not only serves as a practical alternative to traditional waste management methods but also supports a more sustainable and economically beneficial approach to recycling plastic waste into usable fuel similar to gasoline. This method could significantly reduce the environmental impact of plastic waste and support economic development through innovative recycling technologies.
... The brake thermal efficiency deviation of LPWPO with HC ---CH dual fuelling is mentioned in Fig. 16. At high load, LPWPO has a 5.55 % reduced BTE than diesel on account of the lower atomization and fuel vaporization produced by the more viscosity of the LPWPO than diesel (Muthukumar and Kasiraman, 2023;Thangavel et al., 2023b). Compared to diesel, there was a − 0.85 %, 2.02 %, 4.89 %, and 7.72 % increased percentage variation in BTE obtained by LPWPO+1 HC ---CH, LPWPO+2 HC ---CH, LPWPO+3 HC ---CH, and LPWPO+4 HC ---CH respectively at high load. ...
Wastes are not useless, but they are used less. Wastes can be reduced by utilization not by destroying. The
unobserved single-used low-density polyethylene (LDPE) plastic wastes are the sources that produce the fuel
energy for the CI engines by pyrolysis. This downcycles the LDPE wastes. This neat LDPE plastic waste pyrolysis
oil (LPWPO) has lower performance and slightly higher carbon emissions than diesel. To rectify this challenge, a
premixed charge of air–acetylene is inducted into a 1500 rpm 5.2 kW CI engine at 1–4 lpm of flow rate. Acetylene
is admitted into the inlet manifold to vary the mixture strength. Up to 26 % of acetylene energy share is involved
in the premixed combustion with LPWPO. At full load,4 lpm of acetylene induction with LPWPO oil produced
14.05 %, and 22.96 % increased BTE, and peak pressure than neat LPWPO respectively. At the same condition
have 61.35 %, 87.5 %, 31.84 %, 22.64 % percentage reduction in soot (7.11 g/kWh), CO (3.71 g/kWh), UHC
(0.18 g/kWh), and CO2 (732.1 g/kWh) emission than neat LPWPO respectively. However, the increased peak
pressure increases the NOx emission. Therefore, Acetylene (4 lpm) induction with LPWPO is recommended for
improved performance with reduced carbon and soot emissions. This method supports the LPWPO oil use in CI
engines and indirectly supports the downcycling of single-use LDPE plastic waste in the environment.
... It is frequently promoted as a potential fuel additive for IC engines to increase fuel efficiency and decrease emissions, owing to its superior combustion properties and ease of production on board. To address the challenges associated with introducing gaseous fuel into the combustion chamber, dual-fuel operation is considered more suitable for CI engines (Sene et al., 2017;Al-Rousan, 2010;Thangavel et al., 2023). Employing a liquid fuel as the pilot fuel in a dual-fuel system helps maintain the necessary ignition properties for combustion. ...
... Thangavel, Subramanian, and Ponnusamy [17] investigated the effect of H2 and HHO gas induction on the BTE of a dual-fuel compression ignition engine. The research revealed that while hydrogen and HHO gas can enhance engine efficiency, their benefits vary with flow rates and operational conditions. ...
In response to the pressing need to mitigate greenhouse gas emissions, there is increased interest in the potential of hydrogen as an alternative fuel in compression ignition engines. Onboard hydrogen production emerges as a solution, especially for existing diesel engines. This strategy promises to enhance engine performance and solve challenges like hydrogen storage and transportation. The study aims to provide empirical insights into how small quantities of hydrogen influence combustion processes in diesel engines, thereby laying the foundation for onboard hydrogen production as a viable transitional fuel strategy. To this end, this study employs natural flame luminosity and OH* chemiluminescence techniques in an optical single-cylinder AVL 5402 research engine equipped with high-precision sensors and operated under both part- and full-load conditions at 2000 rpm, using diesel as the primary fuel and incorporating small amounts of hydrogen. In the case of part-load Natural Flame Luminosity, hydrogen addition slightly decreased early combustion luminosity and led to earlier combustion completion, attributed to hydrogen's properties and lean air-fuel mixture. At full-load in Natural Flame Luminosity, hydrogen showed increased luminous intensity in the premixed phase, suggesting increased energy release early in the expansion stroke that can lead to potential fuel efficiency improvements. However, later stages were dominated by soot incandescence. OH* chemiluminescence imaging at full load confirmed trends from Natural Flame Luminosity and revealed that hydrogen led to a more uniform flame, better radical distribution and higher luminoust intensity, enhancing all combustion phases as well as the post-combustion period compared to pure diesel. This is likely due to hydrogen's influence on OH* radical formation. Prolonged OH* radical emissions in post-combustion might suggest enhanced soot and CO oxidation, but possibly increased NO emissions. Even at low levels as minimal as 0.42 mg/s, hydrogen had a consistent positive impact on combustion quality. These findings substantiate the potential of hydrogen micro-addition as a transitional fuel strategy and set the stage for future studies focusing on advanced optical imaging techniques and quantifying this strategy's impact on diesel engine performance and emissions.
... This study used diesel fuel as the main fuel energy fraction, and oxy-hydrogen fuel was substituted into the combustion. Diesel fuel specifications are given in Table 2, meanwhile, oxyhydrogen fuel is mainly oxygen and hydrogen gases from the electrolysis process (Gad et al., 2020;Khan et al., 2021;Thangavel et al., 2023). The diesel injection parameters were maintained at all experiment conditions as manufactured on the engine sets. ...
Reducing carbon emissions such as carbon dioxide (CO2) and carbon monoxide (CO) from diesel engines struggled with engine performance challenges and fossil fuel limitations. Besides, huge transportation such as ships hardly replaced diesel engines due to the higher thermal efficiency and low operation cost. Oxy-hydrogen gas, as a carbon-free gas, could potentially improve diesel engine performance and carbon emissions. Most of the studies tried to identify the effect of oxy-hydrogen induction into diesel engine combustion on performance and emissions. However, this study evaluated oxy-hydrogen injector sizes to the diesel engine performance and carbon emissions at several loads and several engine speed conditions. Overall, the result showed that the oxy-hydrogen gas injection into the diesel engine’s intake port improved the performance and carbon emissions compared to the single diesel fuel as a baseline. High engine performance with low carbon emissions could be achieved at low and medium engine load conditions with high engine speeds. Moreover, smaller oxy-hydrogen injector sizes were suitable for the medium engine load and vice versa, to improve the performance and carbon emissions. At low load, the engine performance improvement of engine torque, specific fuel consumption, and thermal efficiency were 1800 to 2200 rpm. Moreover, the CO2 and CO emissions reductions were also suitable with 2200 rpm with a bigger oxy-hydrogen gas injector (6 mm). Furthermore, at medium load, the engine performance improved at 1400 rpm but the CO2 and CO emissions were lower at 2200 rpm with a small oxy-hydrogen gas injector (4 mm). The engine operation at 2200 rpm with a 4 mm injector also improved the engine performance regarding carbon emissions reduction. However, injecting oxy-hydrogen gas into diesel engines had the potential to enhance the engine performance and reduce carbon emissions, moving closer to achieving zero emissions
... Conversely, introducing alcohol to biodiesel enhances BTE due to the alcohol's superior flame speed and oxygen content. The inclusion of hydrogen in fuel blends leads to a progressive increase in BTE with rising hydrogen flow rates [38]. This can be attributed to hydrogen's higher specific heat ratio in comparison to conventional fossil fuels. ...
The research primarily focuses on investigating the impact of hydrogen induction on the parameters of a compression ignition (CI) engine utilizing biodiesel blended with decanol, up to knock limit. The utilization of non-edible oil, exemplified by Prosopis Juliflora seed oil (JFO), presents inherent challenges due to its elevated viscosity, limited atomization, and suboptimal combustion attributes. However, the conversion of JFO into Prosopis Juliflora methyl ester (JFME) biodiesel substantially ameliorates its fuel characteristics, although it still exhibits relatively lower performance in comparison to conventional diesel fuel. To enhance the attributes of JFME blends, decanol is mixed with 20 % on volumetric basis (referred to as D20). Furthermore, the introduction of hydrogen into the engine's intake manifold is employed to bolster performance and curtail emissions. Different hydrogen flow rates, spanning from 2.5 to 10 litres per minute (lpm), are assessed in conjunction with the D20 biodiesel blend. The inclusion of hydrogen into D20 blends yields an enhancement in brake thermal efficiency (BTE), coupled with reductions in hydrocarbon (HC), carbon monoxide (CO), and smoke emissions. However, it should be noted that hydrogen's notable flame velocity and higher calorific value engender escalated combustion temperatures and an associated rise in Nitric oxide (NO) emission. The research also encompasses an evaluation of engine vibration during dual-fuel operation, revealing a proportional increase in engine vibration with heightened rates of hydrogen induction. In summation, the utilization of D20 in conjunction with hydrogen at a rate of 10 lpm emerges as a viable approach for operating diesel engines in a dual-fuel mode.
... Fig. 9 (a) shows the discrepancies in BTE of the hydrogen and WLPO dual-fuelled engine at various loads compared to neat WLPO and diesel. The neat WLPO has lesser BTE than diesel because of the lesser calorific value and higher viscosity, which delays fuel vaporisation and atomisation [47,87]. The hydrogen induction with neat fuel increases the BTE by increasing the amount of hydrogen participating in the combustion [88]. ...
... But due to the presence of antioxidants, the NOx emissions are 12% more than the diesel fuel which were minimized by 2% using the EGR techniques. From the investigation of [12], it is observed that the engine operated on dual mode with hydrogen and hho gas improves the BTE, when the engine was run with a maximum energy-share ratio of 86% with hydrogen and 70% with HHO gas. This also help in the prevention of frequent maintenance of combustion chambers and less scavenging is required to exhaust the gases for fresh air supply. ...
Hydrogen has been identified as a clean and renewable energy source that has a significant potential to replace fossil fuels. The effective production of hydrogen on a commercial scale, however, presents a vital obstacle in today's world. Water splitting electrolysis, which offers high energy conversion and storage capabilities, has emerged as a promising approach for achieving the efficient hydrogen production to address this issue. This experimental research focuses on the production of hydrogen-oxygen gas through the electrolysis process. HHO gas provides promising benefits in terms of better combustion and lower emissions. Therefore, it also focuses on how best HHO gas can be utilized in diesel engines to improve the performance and to reduce the emissions. HHO gas produced at 60 L per hour through electrolysis process is mixed with air in a mixing chamber. Also, Palm munja methyl ester of 10% and diesel fuel of 90% was volumetrically blended to get B10 biodiesel. Therefore, totally four test fuels (Diesel, Diesel + HHO, B10, and B10 + HHO) were tested on a single-cylinder Kirloskar water-cooled direct injection diesel engine under different engine speeds ranging from 1447 to 1550 rpm. The engine injector pressure was varied from 200, 220, and 240 bar during the experiments with an interval of 20 bar. The engine has been modified for hydrogen and oxygen inlet at the entrance manifold 6 cm away at an angle of 30°. The results shows that at 200 bar injection pressure with B10 + HHO blend exhibits better performance and released lower emissions. The performance results also show that the brake thermal efficiency was improved up to 14.16%, and the brake power was increased by 3.22%, while the brake-specific fuel consumption is reduced by 11.53%. The emission results show that CO, HC, NOx, and CO2 emissions were reduced by 20.87%, 11.47%, 1.96%, and 5.22%, respectively. Therefore, it can be concluded that B10 + HHO provides better performance and the lowest emissions compared with other blends.
... These are 5.19%, 5.96%, and 6.67% lesser than diesel BTE respectively, as mentioned in Fig. 6(c). This decrease in the BTE is due to the fuel's higher viscosity which reduces the fuel atomization and involvement of the EGR, which reduces proper combustion in the cylinder (Thangavel et al., 2023). The POLPW has a lesser calorific value than the diesel, and this also influences the BTE variation (Ghodke, 2021). ...
... The main sources of smoke include a locally formed and generally rich fuel-air mixture and the combustion of lubricating oil. Smoke emissions depend on the H/C ratio, the amount of oxygen present in diffused combustion, the complexity of the overall fuel mixture and combustion duration [86]. It was found that minimum smoke emission was found for C7D3H8E10, which was 67.2%, 36.9%, ...
This article investigates the effect of hydrogen induction on the characteristics of a CI engine fueled with the blend of camphor oil and diesel, along with diethyl ether (DEE) as an additive. The fuel sample was prepared by mixing 70% camphor oil with 30% diesel (C7D3) on a volume basis and then tested with 4 LPM (C7D3H4), 6 LPM (C7D3H6), and 8 LPM (C7D3H8) of hydrogen induction on the engine intake manifold. DEE was mixed at 10% and 20% with 90% and 80% of C7D3 on a volume basis and evaluated with 8 LPM of hydrogen induction; the resulting mixtures were designated as C7D3H8E10 and C7D3H8E20. The maximum thermal efficiency for C7D3H8E10 is 32.97%, with a minimum BSEC of 10.91 MJ/kgh, CO of 5.22 g/kWh, HC of 0.206 g/kWh, and smoke opacity of 39.6%. Hydrogen induction and increasing the quantity of hydrogen from 4 lpm to 8 lpm in the manifold increases the thermal efficiency to 32.63%. Further, it reduces the BSEC to 11.03 MJ/kgh, CO of 5.65 g/kWh, HC of 0.222 g/kW, and smoke opacity of 46.3%. NOx emissions were found to increase while increasing the hydrogen induction and with a 10% DEE addition to the C7D3 fuel. Further, raising the DEE from a 10%–20% ratio reduces the thermal efficiency and increases the BSEC, CO, HC, and smoke emissions. Overall, C7D3 in CI engines with 10% more DEE and hydrogen induction up to 8 LPM may be used efficiently.
... Brake thermal efficiency is a vital performance characteristic of an IC engine (Thangavel et al., 2022). Brake thermal efficiency is an evaluation of the engine's potential to convert heat which is generated from fuel into mechanical energy. ...
Due to the increasing growth of industrialization and transportation, fuel consumption of fossil fuel as the main energy source is increasing exponentially which is undoubtedly crucial for world growth; however, exhaust emissions are hampering the environmental health to a large extent. Efforts have been undertaken in recent years to minimize harmful emissions from diesel engines by exploring alternative fuels. This study aims to investigate the performance and emission characteristics of a CI engine in dual fuel mode using Karanja oil biodiesel/diesel in various proportions along with liquefied petroleum gas (LPG) that is supplied as a secondary fuel. The effect of different fractions of biodiesel to LPG on emission and performance of an engine at different loads is studied. The performance characteristics like specific fuel consumption and brake thermal efficiency are analyzed. Various exhaust emissions like of carbon dioxides, carbon monoxides, and nitrogen oxides are calculated at different LPG fractions and blends. Response surface methodology (RSM)–based multi-objective optimization technique is used to optimize the engine performance and emission characteristics and is validated with an experimental data. Optimized values like brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), emission of nitrogen oxides (NOx), hydrocarbon (HC), and carbon monoxide (CO) were 23.2962%, 0.294243 g/kWh, 384.121 ppm, 22.0585 ppm, and 0.0295123%, respectively. Consequently, this study recommends to keep inputs, load (%), LPG (%R), and biodiesel (%Vol) near to 53.84, 18.99, and 20 respectively to get best and optimized results.
Jack fruit peel oil (JFPO) exhibits passive chemical characteristics; thereby, dual-fuel mode frequently involves hydrogen to address its combustion difficulties. This strategy has been gaining prominence nowadays. The present investigation investigates on the performance, emission, and combustion characteristics of a direct injected compression ignition dual-fuel engine operating on a binary fuel blend of jack fruit peel oil (JFPO) and diethyl ether with hydrogen induction. The engine was operated by inducing hydrogen gas into the intake manifold of the engine at 8 and 10 LPM with the applied load ranging from 25 to 100%. The test fuel was prepared by blending jack fruit peel oil and diethyl ether in the volumetric ratio of 90:10. JFP brake thermal efficiency was 16% lower than diesel at full load but enhanced by 9% with direct hydrogen induction at a knock limit of 10 LPM and 23% with JFP + H2 + 10% DEE at maximum load. At maximum load, JFP + 10 LPM of hydrogen gas + 10% DEE produces 916 ppm of NOx, which is 44.46% less than diesel. Furthermore, adding hydrogen gas and DEE to air fuel mixture decreased emissions of carbon monoxide and unburned hydrocarbon by 0.702% and 28.30% opa, respectively.
This article aims to study the impact of camphor oil premixing with intake air on compression ignition (CI) engine characteristics powered with jatropha oil and cottonseed oil. The experiment is conducted on the direct injection compression engine attached to the premixing setup. The investigation reveals that premixing of camphor oil with cottonseed oil and jatropha oil escalates the thermal brake efficiency to 35.02% and 33.62% and brings down the brake‐specific energy consumption to 10.27 and 10.70 kJ kWh⁻¹. At all loading conditions, the premixing of camphor oil and the rise of camphor oil in premixing proportions increase the volumetric efficiency and cut the exhaust gas temperature. 20% premixing of camphor oil with cottonseed oil and jatropha oil drops the smoke opacity emissions by 22.23% and 11.86% and NO emission by 23.27% and 14.59%, respectively, at full load conditions. Further, it shows a 27.60% and 21.14% hike in CO emissions and a 31.34% and 31.87% hike in HC emissions at full load conditions. The in‐cylinder pressure, heat release rate, and mean gas temperature increase with increasing the energy share of camphor oil in premixing. Overall, the premixing of camphor oil shows better CI engine attributes except HC and CO emissions.
Due to the inert chemical properties of custard apple seed oil (CASO), one standard method for overcoming the challenges with its combustion is to use hydrogen as a supplemental fuel in dual-fuel mode. This is a technique that has developed in prominence in recent years. This investigation aims to examine the combustion characteristics of a DI engine that has been fuelled with CASO-blended di-ethyl ether (DEE), as well as hydrogen used as a secondary fuel. The experiment was conducted in atmospheric air with hydrogen enrichment (8 and 10 LPM) using CASO and CASO + 20% DEE as fuel for load condition varying from (25–100%). When compared to diesel at full load, the brake thermal efficiency of CASO was lower by 16%; however, it was improved by 9% with direct hydrogen induction at a knock limit of 10 LPM; and it was improved by 23% with CASO + H 2 + 20% DEE when operating at maximum load. NO x emissions for CASO + 10 LPM H 2 + 20% DEE at maximum load is 926 ppm, which is around 45.46% less than the emission value for diesel. When more hydrogen was added to the combination, the presence of DEE in the fuel caused a reduction in the emissions of both hydrocarbon and carbon monoxide around 21.70% opacity and 0.711%vol, respectively, which leading to a cleaner environment.
The Chemkin ® calculation software platform was used in this paper, using benzene, toluene, and phenol as tar model compounds, and the cracking law of Brown’s gas to tar model compounds was studied by sensitivity analysis at the temperature of 892.5 K and 1130.5 K, respectively. The results showed that the active free radicals of -H and -O in Brown’s gas promote the breaking of methyl bonds and hydrogen bonds, and the formation of phenoxy ions. With the increasing temperature, the secondary products also promote the tar components cracking. Brown’s gas plays an obvious catalytic role in tar cracking, reducing the activation energy of the reaction, and resulting in a decrease in cracking reaction temperature. In addition to active free radicals of Brown’s gas involved in tar cracking, the phenoxy ions also indirectly affect the tar cracking rate.
In this study, the potential of gaseous fuels such as hydrogen, methane, and hythane in combination with diesel fuel is assessed in a closed loop thermodynamic framework. An experimental test is conducted with basic diesel fuel and then the model is configured based on the realistic one‐cylinder diesel engine to evaluate the robustness and reliability of the simulation. The model is accurate in terms of in‐cylinder pressure, temperature, and heat release rate within the 3% error band. In principle, three blend cases of diesel50%—methane50%, diesel50%—hydrogen50%, and diesel50%—hythane50% are compared with baseline neat diesel from engine performance to emissions characteristics. For hythane and hydrogen‐involved fuels, the 10% water injection effect is analyzed as well to damp the high flammability and ignition intensity of hydrogen. The findings indicate that the entropy generation in hythane and hydrogen is markedly higher than in diesel case, while water injection can slightly decrease the entropy amount. It is shown that D50H50 has more fuel consumption in higher nozzle diameter (28% at 1 mm hole diameter), while in lower nozzle size range pure diesel fuel consumption dominates. The results revealed that D50Hy40W10 is particularly effective for elevated torque at lower nozzle hole values since the steam contributes toward maximized pressure and the exerted force. The increase of the nozzle number resulted in the CO content increase in the exhaust with the burning temperature reduction.
Alternative fuels are extremely important in terms of both performance and emission values. Natural gas and hydrogen are the foremost effective alternative fuels due to the high energy density and the environmentalist. In the present study, the effects of adding the hydrogen on the performance and emission values in a single-cylinder natural gas-diesel dual fuel engine at partial load was numerically investigated by ANSYS Forte CFD program. In addition, taking into account the effects of different diesel fuel injection advances, the study was expanded. Analyzes were based on two different modes. The first mode (Mode 1) was based on the sharing of energy between gas fuels (natural gas-hydrogen). The second mode (Mode 2) included the effects of hydrogen enrichment on natural gas. Natural gas and hydrogen mixtures in appropriate proportions provided improvements in performance and emission. Increasing the diesel fuel injection advance (after 30o CA BTDC) caused results to deteriorate, especially at high hydrogen ratios. The fact that the hydrogen ratio in the gas mixture was above 50% caused the engine to operate with knock tendency. In the study, highly effective improvements were achieved without knock tendency in the proper diesel injection advance (10o-18o CA BTDC) and gas mixtures (below 50% hydrogen). There was a 21% and 30% improvement in power and total BSFC values for Mode 1 (14o CA BTDC of SOI and D25NG50H25 mixture), respectively, and 36% and 23% for Mode 2 (10o CA BTDC of SOI and D25NG75H15 mixture). On the other hand, NOx emission was found to be increased by 12% and 11%. The main reason for the increase in NOx emissions was that hydrogen increased local temperatures. However, CO, UHC and PM emissions were sharply reduced as a result of the increase the hydrogen content in the gas fuel. For Mode 1 and Mode 2, CO, UHC and PM emissions decreased by 86%, 89%, 78% and 80%, 76%, 84%, respectively. While increasing the hydrogen ratio was not very effective on ignition delay at low injection advances (10o- 14o CA BTDC), it was extremely effective for thermal efficiency. The thermal efficiency showed an improvement of 21% and 18% for the optimum cases of Mode 1 and Mode 2, respectively.
Hydroxy gas (HHO) is one of the potential alternative fuels for spark ignition (SI) engine, notably due to simultaneous increase in engine performance and reduction in exhaust emissions. However, impact of HHO gas on lubrication oil for longer periods of engine operation has not yet been studied. Current study focuses on investigation of the effect of gasoline, CNG and CNG-HHO blend on lubrication oil deterioration along with engine performance and emissions in SI engine. HHO unit produces HHO gas at 4.72 L/min by using 6 g/L of KOH in the aqueous solution. CNG was supplied to the test engine at a pressure of 0.11 MPa using an electronically controlled solenoid valve. Engine tests were carried out at different speeds at 80% open throttle condition and various performance parameters such as brake power (BP), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature and exhaust emissions (HC, CO2, CO and NOx) were investigated. In addition, various lubrication oil samples were extracted over 120 h of engine running while topping for drain out volume and samples were analyzed as per ASTM standards. CNG-HHO blend exhibited better performance i.e. 15.4% increase in average BP in comparison to CNG, however, 15.1% decrease was observed when compared to gasoline. CNG-HHO outperformed gasoline and CNG in the case of HC, CO2, CO and brake specific fuel consumption (31.1% decrease in comparison to gasoline). On the other hand, CNG-HHO produced higher average NOx (12.9%) when compared to CNG only. Furthermore, lubrication oil condition (kinematic viscosity, water contents, flash point and total base number (TBN)), wear debris (Iron (Fe), Aluminum (Al), Copper (Cu), Chromium (Cr)) and additives depletion (Zinc (Zn), Calcium (Ca)) presented a significant degradation in the case of CNG-HHO blend as compared to gasoline and CNG. Lubrication oil analyses illustrated 19.6%, 12.8% and 14.2% decrease in average viscosity, flash point and TBN for CNG-HHO blend respectively. However, average water contents, Fe, Al and Cu mass concentration appeared 2.7%, 25×10−6, 19×10−6, and 22×10−6 in lubrication oil for CNG-HHO respectively.
Recently, using hydrogen or hydrogen-rich gas as a supplement fuel for spark ignition and compression ignition engines is one of the potential solutions for improving brake thermal efficiency, reducing fuel consumption and pollution emissions from internal combustion engines. This article investigates the effect of HHO gas addition on engine performance and emission characteristics. HHO gas was produced by the electrolysis process of distilled water and stored in a high pressure tank before injected into the intake manifold. The experimental study was carried out on a 97 cc SI engine equipped with two injection systems (HHO gas and addition air) on the intake manifold. The tests were divided into two cases: hybrid HHO/gasoline and HHO/gasoline with addition air from second injection. The experiments showed that, of both cases, compared to original engine, the engine performance was improved and the gasoline fuel consumption was declined after enrichment of HHO gas and of HHO gas/addition air mixture,. The NO x emission was increased; however, HC emission was reduced. The CO and CO 2 emissions displayed different trends between the two cases. When only HHO gas was injected, the CO emission surged due to rich mixture, while it was decreased after the supplying the addition air in the second case. The CO 2 emission trend was in opposite direction of CO. The study demonstrated that the effect of HHO gas addition is most apparent at light loads and lean conditions.
In this paper we present, apparently for the first time, various measurements on a mixture of hydrogen and oxygen called HHO gas produced via a new electrolyzer (international patents pending by Hydrogen Technologies Applications, Inc. of Clearwater, 7 Florida), which mixture is distinctly different than the Brown and other known gases. The measurements herein reported suggest the existence in the HHO gas of stable clusters composed of H and O atoms, their dimers H-O, and their molecules H2 ,O 2 9 and H2O whose bond cannot entirely be of valence type. Numerous anomalous experimental measurements on the HHO gas are reported in this paper for the first time. To reach their preliminary, yet plausible interpretation, we introduce the working hypothesis 11 that the clusters constituting the HHO gas constitute another realization of a recently discovered new chemical species called for certain technical reasons magnecules as well as to distinguish them from the conventional "molecules" (Santilli RM. Foundations 13 of hadronic chemistry with applications to new clean energies and fuels. Boston, Dordrecht, London: Kluwer Academic Publisher; 2001). It is indicated that the creation of the gaseous and combustible HHO from distilled water at atmospheric temperature and 15 pressure occurs via a process structurally different than evaporation or separation, thus suggesting the existence of a new form of water, apparently introduced in this paper for the first time, with the structure (H × H)-O where "×" represents the new 17 magnecular bond and "−" the conventional molecular bond. The transition from the conventional H-O-H species to the new (H × H)-O species is predicted by a change of the electric polarization of water caused by the electrolyzer. When H-O-H is 19 25
In this study, hydroxy gas (HHO) was produced by the electrolysis process of different electrolytes (KOH(aq), NaOH(aq), NaCl(aq)) with various electrode designs in a leak proof plexiglass reactor (hydrogen generator). Hydroxy gas was used as a supplementary fuel in a four cylinder, four stroke, compression ignition (CI) engine without any modification and without need for storage tanks. Its effects on exhaust emissions and engine performance characteristics were investigated. Experiments showed that constant HHO flow rate at low engine speeds (under the critical speed of 1750 rpm for this experimental study), turned advantages of HHO system into disadvantages for engine torque, carbon monoxide (CO), hydrocarbon (HC) emissions and specific fuel consumption (SFC). Investigations demonstrated that HHO flow rate had to be diminished in relation to engine speed below 1750 rpm due to the long opening time of intake manifolds at low speeds. This caused excessive volume occupation of hydroxy in cylinders which prevented correct air to be taken into the combustion chambers and consequently, decreased volumetric efficiency was inevitable. Decreased volumetric efficiency influenced combustion efficiency which had negative effects on engine torque and exhaust emissions. Therefore, a hydroxy electronic control unit (HECU) was designed and manufactured to decrease HHO flow rate by decreasing voltage and current automatically by programming the data logger to compensate disadvantages of HHO gas on SFC, engine torque and exhaust emissions under engine speed of 1750 rpm. The flow rate of HHO gas was measured by using various amounts of KOH, NaOH, NaCl (catalysts). These catalysts were added into the water to diminish hydrogen and oxygen bonds and NaOH was specified as the most appropriate catalyst. It was observed that if the molality of NaOH in solution exceeded 1% by mass, electrical current supplied from the battery increased dramatically due to the too much reduction of electrical resistance. HHO system addition to the engine without any modification resulted in increasing engine torque output by an average of 19.1%, reducing CO emissions by an average of 13.5%, HC emissions by an average of 5% and SFC by an average of 14%.
Using hydrogen as an additive to enhance the conventional diesel engine performance has been investigated by several researchers and the outcomes are very promising. However, the problems associated with the production and storage of pure hydrogen currently limits the application of pure hydrogen in diesel engine operation. On-board hydrogen–oxygen generator, which produces H2/O2 mixture through electrolysis of water, has significant potential to overcome these problems. This paper focuses on evaluating the performance enhancement of a conventional diesel engine through the addition of H2/O2 mixture, generated through water electrolysis. The experimental works were carried out under constant speed with varying load and amount of H2/O2 mixture. Results show that by using 4.84%, 6.06%, and 6.12% total diesel equivalent of H2/O2 mixture the brake thermal efficiency increased from 32.0% to 34.6%, 32.9% to 35.8% and 34.7% to 36.3% at 19 kW, 22 kW and 28 kW, respectively. These resulted in 15.07%, 15.16% and 14.96% fuel savings. The emissions of HC, CO2 and CO decreased, whereas the NOx emission increased.
The increase in the compression ratio reduces the fuel consumption and improves the performance. These effects of compression ratio could be observed in all of the engines, such as compression or spark ignition engines. Moreover, due to the compression ratio constraint based on the knocking phenomenon in spark ignition engines, there will always be an optimal compression ratio, which is one of the most fundamental factors in engine design. The optimum compression ratio could be achieved depending on the type of fuel, but in the case of bi-fuel engines, since the nature of each fuel is different, the design must be relatively optimal for both fuels. In this work, by using the VCR (variable compression ratio) strategy, the bi-fuel EF7 engine performance, combustion, and emissions were investigated in different compression ratios when the engine uses gasoline or HCNG (hydrogen enriched compressed natural gas) as fuel. The results revealed that by changing the compression ratio from 11.05 (actual compression ratio of engine) to 11.80 in HCNG mode, an increase of 13% in power could be achieved. Also CO formation, at the compression ratio of 11.80, was slightly lower (7%) than the compression ratio of 11.05. In addition, by reducing the compression ratio from 11.05 to 10.50 in gasoline mode, there was a significant increase in emissions; that was 44% for the NOx and 16% for the CO, which could be one of the limiting factors of the advance in spark timing. Moreover, due to the VCR strategy and the significant optimization of the compression ratio, the combinatory method of VCR – HCNG can be used as an effective method for the bi-fuel engines in order to improve the performance and reduce emissions.
In addition to other renewable energy sources being used to minimize the environmental pollution and climate change as well as to satisfy the ever-increasing demands of the society on the energy, biogas is considered abundant resources for energy production. The strategies of using biogas source for internal combustion engines may be a good and potential solution for saving fossil fuel and reducing pollution emission. In this current study, hydroxy (HHO) -enriched biogas under two pathways such as dual injection and blend injection was used to fuel an SI engine aiming to assess the performance (via in-cylinder pressure and indicated cycle work) and emission characteristics (CO and NOx emissions) when the input parameters including HHO/biogas ratios, the position of butterfly valve in the intake manifold, angle of HHO injection were varied. As a result, the dual injection strategy of HHO-enriched biogas produced an advantageous distribution of H2 and CH4 in combustion chamber, which improved combustion efficiency and reduced pollutant emissions. With a fixed HHO injection duration of 2.7 ms, the dual injection led to an increase in HHO concentration at all engine loads, which improved complete combustion in critical operating conditions. Increase of HHO content led to a decrease of optimal advance ignition angle and reduced the range of its variation with engine speed. In closing, HHO addition into biogas was found to improve the engine performance, to reduce CO emission, although it also increases NOx concentration. Biogas enriched by 20% HHO was considered as the best compromise between engine performance and pollution emissions with indicated engine cycle work of 204 J/cyc, CO emission of 0.74%, and NOx emission of 1192 ppm. Moreover, the ignition maps for biogas and HHO were built to point out the optimal range of advance ignition timing for the application purpose to real experiments in the future.
Stringent emission norms being followed throughout the world increases the demand for clean and green fuels. Gaseous fuels like compressed natural gas (CNG), liquefied petroleum gas (LPG) and hydrogen are promising alternatives to conventional diesel and gasoline. The use of hydrogen in the IC engine has gained interest among the researchers as it can be easily produced from water through electrolysis. Electrolysis of water produces stoichiometric mixture of hydrogen and oxygen in the ratio of 2:1. This study investigates the performance and emission characters of introducing hydrogen and HHO gas in the inlet manifold of a compression ignition engine in dual fuel mode. Experiments were conducted at 5 different torque conditions where hydrogen and HHO gases are supplied at the flow rate of 6, 12, 18, 24, 30 and 36 LPM along with air in the inlet manifold. The HHO gas was synthesized using stored hydrogen and oxygen in the ratio of 2:1. The performance and emission characteristics were noted for all the conditions. The introduction of hydrogen and HHO gas has reduced the diesel energy share ratio by 86% and 70% respectively at no torque condition.
HC emission was found to be decreased at high torque condition when compared to neat diesel operation. Significant increase in NOx emission was noted with increase in gases substitution and torque. CO2 and smoke emissions showed positively decreasing trend as the gas percentage increases, due to reduction in carbon content of the fuel mixture. The cylinder pressure reduced with increase in the flow rate of gases. Combustion duration increases with increase in flow rate as well as increase in torque. It was noted that Brake Thermal Efficiency (BTE) reduced for all operating conditions except at 6 LPM of HHO gas addition in the combustion chamber.
Petroleum (Hydrocarbon – HC) based fuels are used for powering automotive and local power generation systems. Hydrocarbons on combustion produce gases such as CO2, CO, HC and NOx which affect human health as well as environment. Introduction of Hydrogen in Internal Combustion (IC) engine reduces emission and increases the performance. HHO gas which is produced through electrolysis of water can be used instead of hydrocarbon based fuels as the gas contains both Hydrogen as well as oxygen. Due to the challenges in storing Hydrogen, HHO gas is produced onsite through electrolysis process. This article presents the investigation on producing HHO gas through electrolysis onsite. A numerical calculation was done using empirical formula to predict the production of HHO gas. The electrolyser's performance analysis showed that maximum of 0.75 LPM of HHO gas was produced at 80 °C and by supplying 40 A-h. The numerical calculation showed that at the similar working condition the HHO gas produced was 1.3 LPM. The trend of both experiments and model was same for varying the current and rate of generation of HHO gas. This article also presents the effect of parameters such as concentration of electrolyte solution on potential, effect of time and the effect of temperature on production rate. The energy required and the number of modules or units of HHO gas production for real time engine application has been analysed and reported.
In this study, energy, exergy, and emission analysis were investigated for the hydroxyl fueled compression ignition (CI) engine under dual fuel mode. Hydroxyl gas (HHO) generator was used to supply three different mass flow rates of HHO (0.25, 0.5, and 0.75 lpm) along with diesel for the experimental work on a modified constant speed CI engine. Significant improvement of 6.5% in brake thermal efficiency was obtained with 0.75 lpm HHO flow rate at 80% load. However, a slight increment in heat transfer losses and energy in exhaust gas were observed by 6.29% and 8.55%, respectively, at the optimized condition. The work availability, exhaust gas, and heat transfer exergy were increased by 6.54%, 5.69%, and 6.36% (0.75 lpm and 80% load), respectively due to the higher diffusivity of hydrogen and faster oxidation of fuel species within the cylinder. A significant reduction in emission parameters was obtained in carbon monoxide, unburnt hydrocarbon, and smoke emission as 53%, 62%, and 49%, respectively. High pressure and temperature within the cylinder improve the rate of oxidation of fuel species, which results in decreased HC, CO, and smoke emission. Furthermore, high temperature increases the NOX emission by 35%. Overall it can be concluded the HHO can be used as a prominent alternative fuel with increased exergy and lower emissions.
A dual-fuel spark-ignition engine that was equipped with a hydrogen (H2) port-injection and methanol direct-injection fuel-supply system was used to study the power, combustion and emission performances in a methanol late-injection strategy. The test was operated at a spark timing of a 20° crank angle before top dead center, engine speed of 1200 rpm and 1800 rpm with a manifold absolute pressure of 70 kPa and 68 kPa, respectively, and H2 addition ratio of 0% and 3%, respectively, under different excess-air ratios. The indicated mean effective pressure decreased with an increase in excess-air ratio at an engine speed of 1200 rpm and 1800 rpm. H2 enrichment could expand the lean-burn limits of a methanol engine without or with H2 addition from excess-air ratio 1.6 to 2.2. H2 addition could shorten the flame-development angle and rapid-burning angle, and advance the combustion central angle closer to top dead center. The coefficient of variation in the indicated mean effective pressure was increased significantly as the excess-air ratio was increased over 1.4 for no H2 addition and 1.8 for H2 addition from a 3% methanol engine at an engine speed of 1800 rpm. Brake-specific nitrogen-oxide emissions decreased as the excess-air ratio was increased. The BSNOX emissions for lean-burn conditions are average 90% lower than for excess-air ratio 1.0. The maximum soot emission for 3% H2 addition at engine speed of 1200 rpm and 1800 rpm is 59% and 30% lower than for no H2 addition, respectively.
In this study, the impact of nanoparticles and hydrogen blends on combustion, performance and emission characteristics of modified dual fuel engine was investigated. The nanoparticles TiO 2 , CNT, Al 2 O 3 , CuO and CeO 2 are dispersed at a fraction of 100 ppm with 20% hydrogen to form blends HT100, HCT100, HA100, HCE100 and HC100 respectively. The nanoparticles are agitated using ultrasonication process to increase the stability of blends. All blends are tested at 1800 rpm for different engine load varying from 0%, 25%, 50%, 75% and 100% respectively. The addition of nanoparticles does not show a substantial effect on density, kinematic viscosity and flash point and cetane number. Further, the nanoparticles CNT and TiO 2 showed a better stability with 30% and 21% absorption rate at 240 h sedimentation time. All tested nanoparticles showed a profound change in the maximum cylinder pressure rates in comparison to neat diesel. Besides, the addition of CeO 2 and Al 2 O 3 improves the brake thermal efficiency by 4.3% and 2.5%. Meanwhile no significant change in brake specific fuel consumption is recorded for CeO 2. The nanoparticles CNT and TiO 2 reports 23% and 22% reduced BSFC than other blends. The results of exhaust emission showed addition of hydrogen and nanoparticles decreases the emission of carbon monoxide, carbon dioxide and hydrocarbon significantly. However, regarding NOx emission only CNT showed a profound decrease in NOx than other blends. From the results it is evident that, addition of nano-particles and hydrogen on neat diesel improves the combustion characteristics and engine performance with reduced exhaust gas emission.
Nowadays, engines design technology tends toward less fuel consumption and emission besides higher efficiency. Hydrogen as a clean fuel has been a point of interest for long time, but in recent years due to fossil fuel increasing prices and stringent environmental laws, more considerations have been made. In addition to the challenges of producing and storing hydrogen as a fuel for internal combustion engines, the engine performance should be independently evaluated. Simultaneous investigation of energy and exergy brings better analysis of internal combustion engines performance and helps researchers to propose more efficient ways for engines development. In this work, energy and exergy analysis of a hydrogen-fueled homogeneous charge compression ignition engine has been done to investigate the effects of engine input parameters on its performance. Considered input parameters are engine speed, inlet pressure and temperature, equivalence ratio and exhaust gas recirculation. To achieve this goal, a single-zone thermodynamic model considering detailed chemical kinetics has been employed which is able to estimate engine performance qualitatively. Results show inlet valve closing (IVC) pressure and equivalence ratio have the greatest impact on irreversibility and exergy terms, while engine speed is the least effective parameter on irreversibility production. Both power and irreversibility increase by IVC pressure enhancement, and furthermore IVC temperature increase reduces charge chemical exergy by engine volumetric efficiency decrease.
Approximately 40% of typical heavy-duty vehicle operation occurs at loaded idle during which time conventional diesel engines are unable to maintain aftertreatment component temperatures in a fuel-efficient manner. Fuel economy and thermal management at this condition can be improved via reverse breathing, a novel method in which exhaust gases are recirculated, as needed, from exhaust to intake manifold via one or more cylinders. Resultant airflow reductions increase exhaust gas temperatures and decrease exhaust flow rates, both of which are beneficial for maintaining desirable aftertreatment component temperatures while consuming less fuel via reduced pumping work. Several strategies for implementation of reverse breathing are described in detail and are compared to cylinder deactivation and internal exhaust gas recirculation operation. Experimental data demonstrate 26% fuel consumption savings compared to conventional stay-warm operation, 60 °C improvement in turbine outlet temperature and 28% reduction in exhaust flow compared to conventional best fuel consumption operation at the loaded idle condition (800 r/min, 1.3 bar brake mean effective pressure). The incorporation of reverse breathing to more efficiently maintain desired aftertreatment temperatures during idle conditions is experimentally demonstrated to result in fuel savings of 2% over the heavy-duty federal test procedure drive cycle compared with conventional operation.
HHO gas, which is obtained by the electrolysis of water, is a promising alternative fuel. This paper presents a review of important features and techniques used for producing HHO gas. Various aspects of the thermodynamics and chemical kinetics of electrolysis reactions are discussed. Design and operating parameters for improving the gas production rate are identified. Widely different hypotheses regarding the structure and composition of HHO gas are compared in depth. The state of the art on the use of HHO gas in Internal Combustion (IC) engines is presented in the latter part of the paper. It is seen that the introduction of HHO gas increases engine torque, power and thermal efficiency, while simultaneously reducing the formation of NOx, CO, HC and CO2. The major challenges in using HHO gas in engines are identified as system complexity, safety, cost and efficiency of electrolysis.
An experimental and numerical study was performed to investigate the impact of Biodiesel B20 (blends 20% Rapeseed methyl ester with 80 % Diesel volumetric fraction) and different energetic fractions of hydrogen content (between 0 and 5%) on the mixture formation, combustion characteristics, engine performance and pollutant emissions formation. Experiments were carried out on a tractor Diesel engine, four-cylinders, four-stroke, 50 kW/2400 rpm, and direct injection. Simulations were conducted using the AVL codes (HYDSIM and BOOST 2013). Simulation results were validated against experimental data, by comparing the inline pressure, needle lift, in-cylinder pressure curves for Biodiesel B20 and pure Diesel fuels at 1400 rpm and 2400 rpm, respectively, under full load operating conditions. Good agreement with a maximum of 2.5% relative deviation on the peak results revealed that overall operation conditions Biodiesel B20 provides lower engine performance, efficiency, and emissions except the NOx which are slightly increased. The Biodiesel B20 has shorter ignition delay. By hydrogen addition to B20 with aspiration of the intake air flow the CO emissions, smoke, and total unburned hydrocarbon emissions THC decreased, while the NOx kept the same increasing trend for 1400 rpm and has not quite apparent trend for 2400 rpm. The enrichment by hydrogen of Diesel and B20 fuels has not a significant effect on ignition delay.
The effects of exhaust gas recirculation (EGR) on combustion and emissions under different hydrogen ratios were studied based on an engine with a gasoline intake port injection and hydrogen direct injection. The peak cylinder pressure increases by 9.8% in the presence of a small amount of hydrogen. The heat release from combustion is more concentrated, and the engine torque can increase by 11% with a small amount of hydrogen addition. Nitrogen oxide (NOx) emissions can be reduced by EGR dilution. Hydrogen addition offsets the blocking effect of EGR on combustion partially, therefore, hydrogen addition permits a higher original engine EGR rate, and yields a larger throttle opening, which improves the mechanical efficiency and decreases NOx emissions by 54.8% compared with the original engine. The effects of EGR on carbon monoxide (CO) and hydrocarbon (HC) emissions are not obvious and CO and HC emissions can be reduced sharply with hydrogen addition. CO, HC, and NOx emissions can be controlled at a lower level, engine output torque can be increased, and fuel consumption can be reduced significantly with the co-control of hydrogen addition and EGR in a hydrogen gasoline engine.
Hydrogen enhanced combustion (HEC) is promoted as an
end-user add-on that has the capability of reducing both engine
tailpipe emissions and fuel consumption. An experimental
investigation was carried out to measure the effects of HEC in
typical engines through laboratory dynamometer testing. Three
engines – (1) a carburetted petrol engine, (2) a fuel injected
petrol engine and (3) a diesel engine – were tested to
investigate the effects of adding hydrogen to the air intake of
the engines and measure the effects on performance and
emissions (HC, CO and CO2). The engines were tested at
different engine speeds and loads to simulate a wide range of
operating conditions. The hydrogen was produced from the
electrolysis of a solution of distilled water and sodium
hydroxide using two different electrolyser designs. The
electrolyser constructions were suitable for automotive
applications, that is, small in size and consuming current within
the capability of a typical car alternator. Both the hydrogen and
oxygen that were produced by electrolysis were added to the
engine‘s intake during the tests. Results showed that the
addition of HHO is most effective in stabilizing and enhancing
the combustion of lean air-fuel mixtures inside the petrol
injected engine, allowing for lower HC, CO and CO2
emissions. Thus hydrogen enhanced combustion could play a
role in stabilizing lean burn petrol engines.
The addition of hydrogen to the gasoline-air mixture may contribute significantly towards accelerating the combustion process, with the beneficial effects on engine performance and emissions. The present contribution describes the results of an experimental research where gasoline-air mixture was enriched with a Hydrogen Rich Gas (HRG) produced by the electrical dissociation of water. The HRG analysis shows the presence of hydrogen and oxygen together with some additional species. Experiments were carried out at engine light and partial load. Detailed results of the measurements are shown, namely engine torque and efficiency, exhaust emissions, cyclic variability, heat release rates and combustion duration. The possibilities of improving engine performance and emissions in correlation with the amount of HRG, the equivalence ratio and the engine operating condition are thus outlined.
During the last decade the use of alternative fuels for diesel engine has received renewed attention. The interdependence and uncertainty of petroleum based fuel availability and environmental issues, most notably air pollution are among the principal forces behind the movement towards alternative sources of energy. The main pollutants from the conventional hydrocarbon fuels are unburned/partially burned hydrocarbon (UHC), carbon monoxide (CO), oxides of Nitrogen (NOx), smoke and particulate matter. These emissions are harmful to human, animal and plant life. Emissions from automobiles are currently a dominant source of air pollution representing 70 % of carbon monoxide, 41 % of oxides of Nitrogen (NOx), 38 % of hydrocarbon emissions globally. In addition 25 % of the man made CO2 emissions globally adds to the green house effect, which results in global warming. In the present investigation hydrogen is used in a diesel engine in the dual fuel mode using diesel as an ignition source. In order to have a precise control of hydrogen flow and to avoid the backfire and pre-ignition problems hydrogen was injected into the intake manifold. Experiments were conducted to determine the optimized injection timing, injection duration and injection quantity of the fuel in manifold injected hydrogen operated engine using diesel as ignition source for hydrogen operations. From the results it is observed that the optimized condition is start of injection at gas exchange top dead center (GTDC) with injection duration of 30° CA with the hydrogen flow rate of 7.5 lpm. The brake thermal efficiency is found to increase by 9 % compared to diesel. Smoke emissions decrease by 4 fold at full load compared to diesel. The NO x emission is almost similar in both hydrogen diesel dual fuel engine and diesel operated engine except at no load. The CO2 emissions decrease substantially by 2 fold at no load where hydrogen substitution is higher compared to full load. Manifold injection system with diesel as ignition source operates smoothly and shows improved performance and emits less pollution than diesel.
With increasing energy prices and concerns about the environmental impact of greenhouse gas (GHG) emissions, a growing number of national governments are putting emphasis on improving the energy efficiency of the equipment employed throughout their transportation systems. Within the U.S. transportation sector, energy use in commercial vehicles has been increasing at a faster rate than that of automobiles. A 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected from 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. and global economies. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. As the economy grows, the freight tonnage increases as well as the annual vehicle miles traveled (VMT). Over 80% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. The improved efficiency of heavy-duty engines and vehicles has been quickly overwhelmed by the increase in annual VMT. This results in heavy-duty vehicles consuming a growing share of the total transportation-related petroleum. Given the vital role that the trucking industry plays in the economy, improving the efficiency of diesel engines is a central focus of this paper. Trucks are the mainstay for trade, commerce, and economic growth. Sustaining a U.S. trucking industry that is competitive in global markets requires innovation. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. A key part of the strategy to meet these requirements is to improve the efficiency of the internal combustion engine (ICE) powering the trucks. The performance, low cost, and fuel flexibility render the ICE the leading candidate to power commercial vehicles for many decades. Historically, diesel engine technologies have taken more than 10 years after first introduced to diffuse throughout the commercial vehicle marketplace. This rate is faster when fuel economy provides a business advantage to the vehicle's owner. Increased efficiency and reduced emissions of diesel engines can be realized through technologies that improve engine design and better integrate systems. Engine manufacturers have a growing need to refine the capability to innovate, design, develop, and validate engine efficiency improvements. Therefore, the primary purpose of this paper is to provide guidelines and tools that allow a systematic approach to engine design and development that focuses on satisfying regulatory requirements, achieving greater fuel efficiency, and improving transportation freight efficiency. The on-highway heavy-duty diesel engine is used to illustrate the processes; however, the general principles may be applied to other diesel and natural gas engine applications, such as off-highway or power generation. For the past two decades, engine manufacturers have focused on reducing engine emissions to near zero levels while maintaining or slightly increasing fuel efficiency. With the implementation of the new EPA/NHTSA commercial vehicle GHG regulations in 2011, the need to reduce fuel consumption has been explicitly linked to the ability to manufacture and sell engines. The forward looking technology roadmaps in this paper provide a framework for improving engine efficiency over the next 10 to 15 years. The list of improvements consists of engine components, aftertreatment, and powertrain advancements.
The gasoline engines always encounter the deteriorated thermal efficiency and increased toxic emissions at part load conditions. This paper investigated the effect of hydrogen/oxygen blends (hydroxygen) addition on the performance of a gasoline engine at different hydrogen volume fractions in the hydroxygen. The experiment was conducted on a 1.6 L gasoline engine equipped with a hydrogen and oxygen port injection system. A hybrid electronic control unit was adopted to control the spark timing and the injection timings and durations of hydrogen, oxygen and gasoline. The test was performed at a typical city driving speed of 1400 rpm, a manifolds absolute pressure of 61.5 kPa and two excess oxygen ratios of 1.00 and 1.20. The overall volume fraction of the hydroxygen in the total intake gas was fixed at 3%. The hydrogen volume fraction in the hydroxygen was raised from 0% to 100% by changing the injection durations of hydrogen and oxygen. The test results demonstrated that the engine thermal efficiency was obviously increased with the increase of hydrogen volume fraction in the hydroxygen. The fuel energy flow rate of the 3% hydroxygen-blended gasoline engine was lower than that of the original engine when the hydrogen volume fraction in the hydroxygen exceeded 70%. Both the flame development and propagation periods were shortened after the hydroxygen addition. HC, CO and NOx emissions were decreased with the increase of hydrogen volume fraction in the hydroxygen. But NOx emissions of the hydroxygen-blended engine were higher than those of the original engine for all hydrogen volume fractions in the hydroxygen. Moreover, at an excess oxygen ratio of 1.00, CO from the 3% hydroxygen-blended gasoline engine was also higher than that from the original engine. The reduced particulate emissions can be obtained only at relatively high hydrogen volume fractions in the hydroxygen. © 2012 Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
The views of the author on a new gaseous and combustible form of water, called HIHO gas, are presented. The author has requested chemistry professionals to verify the existence of the new gaseous and combustible form of water. He states that the new gas is a mixture of several common gases, such as hydrogen, oxygen, and water vapor. Any individual trying to verify the existence of the gas need to be extremely careful, while selecting appropriate application techniques for the verification purpose. He also needs to be significantly careful, while interpreting the resulting data, to convince scientists about the validity of the findings. The author also states that resulting data and findings of about the existence of the gaseous and combustible gas have been misinterpreted and misunderstood.
The fuel used in combustion applications has significant influence on irreversibility generation and hence the exergetic efficiency of the system. This work discusses a method of estimating the availability destructions and exergetic efficiencies of combustion for different classes of fuels viz. hydrogen, hydrocarbons, alcohols and biodiesel surrogates. A ranking of these fuels is presented based on their exergetic efficiencies during isobaric and isochoric combustion. It is observed that availability destruction is greater for heavier hydrocarbon fuels and oxygenated fuels with higher oxygen fraction. Though unsaturated hydrocarbon fuels are associated with lower availability destruction, they result in poor exergetic efficiency as a significant fraction of the fuel availability is lost in the products. Hydrogen and acetylene are identified as the fuels with maximum and minimum exergetic efficiencies respectively. Optimum exergetic efficiency is obtained for reactant mixtures on the leaner side of fuel–air stoichiometry. Availability destruction increases with exhaust gas recirculation (EGR) and decreases with oxygen enrichment of the supplied air. However, oxygen enrichment entails significant chemical availability losses and lowers exergetic efficiency. Preheating the reactants is found to be effective in mitigating availability destruction.
The views of J.V. Kadeisvili on the some of the issues lacked by the comments of J.M. Calo are discussed. Calo's comments have no scientific value due to the lack of prior re-runs of basic measurements, limited knowledge of the technical literature in the field, the addressing of a draft with evident mix-up caused by format conversion, and other reasons. Calo carefully avoids addressing the central scientific need and enters instead into various criticisms of peripheral character. The point disqualifying Calo's comment is that Santilli merely reported signed statements by directors of laboratories. The initial paragraphs of Calo's 'Specific comments' are devoted to an epistemological discussion essentially based on Calo's seemingly studious misinterpretation of Santilli's use of the word 'evaporation' compared to 'electrolytic separation' and other issues so manifestly inessential for the real scientific issues.
The views of Martin O. Cloonan on J.M. Calo's comments on a new gaseous and combustible form of water by R.M. Santilli are discussed. Calo claimed that the fact that the IR spectrum of the HHO gas has the largest absorption in the 2800-3000cm-1 region is consistent with water vapor. This claim is not consistent with the experimental IR data published in the scientific literature for water vapor. Calo also claims that the 18 peak is most certainly nothing but conventional water vapor, but the peak is consistent with H2O but this is not absolute. Calo provides an alternative rational for the widely varying thermal content of the HHO gas but he does not apply this rational to explain why the HHO gas can reach a temperature of 9000°C. Calo has stated that a hydrogen flame in oxygen has a temperature of 3080K. The presence of water vapour in a H2 and O2 mixture cannot account for this temperature difference of over 6000°C by any known law of science.
Besides its renewable nature and low emission advantage, hydrogen has higher exergetic efficiency of combustion compared to hydrocarbon fuels. This makes it an attractive alternative fuel for internal combustion engines. The present work concerns the estimation of irreversibilities associated with various sub-processes occurring during combustion in a hydrogen fueled spark ignition engine. A quasi-three zone phenomenological combustion model is used for predicting the pressure and temperature histories of a single cylinder, four stroke spark ignition engine operating at equivalence ratios of 0.3–0.75 in the speed range 1500–3500 rpm. For each sub-process, the history of availability destruction during combustion and the effects of operating conditions are discussed. Measures are proposed for improving the exergetic efficiency by mitigating availability destruction. It is observed that chemical reaction is the major contributor to irreversibility generation, followed by pressure equilibration and heat loss to walls. While more than 94% of the fuel supplied undergoes combustion, nearly 20–30% of the reactant availability is destroyed. Charge preheating, product mixing and piston motion are observed to have negligible effects on irreversibility generation.
Automobiles are one of the major sources of air pollution in the environment. In addition CO2 emission, a product of complete combustion also has become a serious issue due to global warming effect. Hence the search for cleaner alternative fuels has become mandatory. Hydrogen is expected to be one of the most important fuels in the near future for solving the problems of air pollution and greenhouse gas problems (carbon dioxide), thereby protecting the environment. Hence in the present work, an experimental investigation has been carried out using hydrogen in the dual fuel mode in a Diesel engine system. In the study, a Diesel engine was converted into a dual fuel engine and hydrogen fuel was injected into the intake port while Diesel was injected directly inside the combustion chamber during the compression stroke. Diesel injected inside the combustion chamber will undergo combustion first which in-turn would ignite the hydrogen that will also assist the Diesel combustion. Using electronic control unit (ECU), the injection timings and injection durations were varied for hydrogen injection while for Diesel the injection timing was 23° crank angle (CA) before injection top dead centre (BITDC). Based on the performance, combustion and emission characteristics, the optimized injection timing was found to be 5° CA before gas exchange top dead centre (BGTDC) with injection duration of 30° CA for hydrogen Diesel dual fuel operation. The optimum hydrogen flow rate was found to be 7.5 lpm. Results indicate that the brake thermal efficiency in hydrogen Diesel dual fuel operation increases by 15% compared to Diesel fuel at 75% load. The NOX emissions were higher by 1-2% in dual fuel operation at full load compared to Diesel. Smoke emissions are lower in the entire load spectra due to the absence of carbon in hydrogen fuel. The carbon monoxide (CO), carbon dioxide (CO2) emissions were lesser in hydrogen Diesel dual fuel operation compared to Diesel. The use of hydrogen in the dual fuel mode in a Diesel engine improves the performance and reduces the exhaust emissions from the engine except for HC and NOX emissions.
In the present paper, the performance and emission characteristics of a conventional four cylinder spark ignition (SI) engine operated on hydrogen and gasoline are investigated experimentally. The compressed hydrogen at 20 MPa has been introduced to the engine adopted to operate on gaseous hydrogen by external mixing. Two regulators have been used to drop the pressure first to 300 kPa, then to atmospheric pressure. The variations of torque, power, brake thermal efficiency, brake mean effective pressure, exhaust gas temperature, and emissions of NOx, CO, CO2, HC, and O2 versus engine speed are compared for a carbureted SI engine operating on gasoline and hydrogen. Energy analysis also has studied for comparison purpose. The test results have been demonstrated that power loss occurs at low speed hydrogen operation whereas high speed characteristics compete well with gasoline operation. Fast burning characteristics of hydrogen have permitted high speed engine operation. Less heat loss has occurred for hydrogen than gasoline. NOx emission of hydrogen fuelled engine is about 10 times lower than gasoline fuelled engine. Finally, both first and second law efficiencies have improved with hydrogen fuelled engine compared to gasoline engine. It has been proved that hydrogen is a very good candidate as an engine fuel. The obtained data are also very useful for operational changes needed to optimize the hydrogen fueled SI engine design.
A new gaseous and This preprint research paper has not been peer reviewed
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Cloonan MO. A chemist ' s view of J. M. Calo ' s comments on : '" A new gaseous and
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