Methanol Engine Research Articles

Combustion and emissions performance of a DME-enriched spark-ignited methanol engine at idle condition

Dimethyl ether (DME) and methanol are thought to be one of the most promising alternative fuels for IC engines. Meanwhile, previous investigations also have pointed out the good prospects for adopting DME and methanol in IC engines. The experiments in this paper were carried out at idle condition to investigate the effect of applying the methanol/DME blended fuel in a SI engine. The engine was modified to be fueled with the mixture of methanol and DME which were injected into the engine intake ports simultaneously. Various DME fractions were selected to investigate the effect of DME addition on engine performance. The experimental results showed that indicated thermal efficiency was increased by 25% and coefficient of cyclic variation in engine speed was decreased by 29.2% at the DME energy fraction of 85.2% in the total fuel. In addition, both flame development and propagation durations were shortened with the increase of DME enrichment level at idle condition. Meanwhile, the largest drop of HC emissions was nearly 50% compared with the original methanol engine at stoichiometric condition. However, CO and NO x emissions increase with the addition of DME.

Regulated emissions from a direct-injection spark-ignition methanol engine

The effects of injection timing, ignition timing, and injection nozzle parameters on the regulated emissions from a high-compression ratio direct-injection spark-ignition methanol engine were investigated experimentally and its emission characteristics were compared with the diesel counterpart. The experimental results indicated that the injection and ignition timings affect exhaust emissions significantly. Best compromises between the brake thermal efficiency and three emission pollutants at the optimal injection and ignition timings were obtained. The effects of injection nozzle parameters on emissions of methanol engine are significant. The THC (total hydrocarbon compounds) emission using an injector of a 10-hole × 0.30 mm nozzle is lower significantly than those of 7-hole × 0.45 mm nozzle in the overall load range and CO (carbon monoxide) emission is also lower, but NO x (nitrogen oxides) emission is higher at high load. The methanol engine is characterized by smokeless combustion. According to the ECE R49-13 mode test procedure, the brake specific NO x emission from the methanol engine is only nearly half that from the diesel counterpart and 11% lower for the CO emission, but 273% higher for the THC emission.

Experimental Study on the Stratified and Homogeneous Charge of a Direct-Injection Spark Ignition Methanol Engine

Based on the gasoline direct-injection spark ignition (DISI) engine technologies and methanol fuel characteristics, a complex-guided multi-hole spray coupled with induction swirl and chamber-wall-guided stratified-charge combustion system for a DISI methanol engine was developed. It was retrofitted from a four-cylinder diesel engine with a compression ratio of 14. It was developed to run on methanol in stratified-charge and homogeneous-charge combustion modes; under part-load operating conditions, stratified-charge combustion is adopted to improve fuel economy while, under high- and full-load conditions, the homogeneous-charge combustion mode is adopted for the purpose of a higher power output. Under both combustion modes, the key parameters of the combustion system were matched and optimized respectively. The operating map for both combustion modes was obtained. Then, the engine power performance, emissions, and combustion characteristics were studied. The power output of the developed methanol engine is higher than that of the original diesel engine. By using the stratified combustion mode under low-load conditions, the engine fuel economy (the brake thermal efficiency) is improved; the stratified-charge combustion of methanol performed relatively well with acceptable values of the coefficient of the cyclic variation in the indicated mean effective pressure. The smoke and nitrogen oxide emissions from the DISI methanol engine are both reduced simultaneously and significantly.

Improvement of fuel economy of a direct-injection spark-ignition methanol engine under light loads

The effects of ignition system, compression ratio, and methanol injector configuration on the brake thermal efficiency (BTE) and combustion of a high-compression direct-injection spark-ignition methanol engine under light loads were investigated experimentally, and its BTE was compared with its diesel counterpart. The experimental results showed that these factors significantly affect the fuel economy under light load. The BTE of a methanol engine using a high-energy multi-spark-ignition system is on average 25% higher than that of one using a single-spark-ignition system at a brake mean effective pressures (BMEP) of 0.11–0.29 MPa and an engine speed of 1600 rpm. Decreasing the compression ratio of the methanol engine from 16:1 to 14:1 markedly increases the BTE under low loads and decreases the BTE at high loads. For the methanol engine, using an injector of a 10-hole × 0.30 mm nozzle decreases the ignition delay and improves the fuel economy compared to when an injector of a 7-hole × 0.45 mm nozzle is used. The combustion duration using an injector of a 7-hole × 0.45 mm nozzle is much longer than that with one of a 10-hole × 0.30 mm nozzle under light loads. As a result, the BTE for a methanol engine with optimal parameters is improved by 27% compared to that for a methanol engine without optimized parameters at a BMEP of 0.17 MPa and an engine speed of 1600 rpm, but the BTE of the optimized methanol engine is 20% lower than that of its diesel counterpart under these operating conditions.

Effects of ambient temperature on firing behavior and unregulated emissions of spark-ignition methanol and liquefied petroleum gas/methanol engines during cold start

The effects of the ambient temperature on the firing behavior and the unregulated emissions (formaldehyde and unburned methanol emissions) of electronically controlled inlet port injection spark-ignition methanol and liquefied petroleum gas (LPG)/methanol engines during the cold start were investigated experimentally by means of a single-cycle fuel injection strategy. The test results indicated that the minimum amount of methanol injected per cycle to ensure the methanol engine reliable firing increases 86% with the reduction of the ambient temperature from 301 to 289 K. With the ambient temperature below 289 K, the methanol engine cannot be started reliably without the other assistant measures even with a large methanol injection. The LPG only played a part of start-aids in the LPG/methanol engine. Using additional LPG injected into the inlet port results in a reliable firing of the LPG/methanol engine at low ambient temperature during cold start. When the ambient temperature drops, the mass ratio of injected LPG/methanol for the reliable firing of the LPG/methanol engine during cold start increases rapidly. The maximum combustion pressure in the cylinder, the maximum instantaneous engine speed, and the formaldehyde emissions increase significantly and the unburned methanol decreases obviously with the rise of the ambient temperature.

Effect of injection and ignition timings on performance and emissions from a spark-ignition engine fueled with methanol

Optimal injection and ignition timings and the effects of injection and ignition timings on performance and emissions from a high-compression direct-injection stratified charge spark-ignition methanol engine have been investigated experimentally. The results have shown that direct-injection spark-ignition methanol engine, in which a non-uniform mixture with a stratified distribution can be formed, has optimal injection and ignition timings to obtain a good combustion and low exhaust emissions in the overall mode range. Both methanol injection timing and ignition timing have a significant effect on methanol engine performance, combustion, and exhaust emissions. At an engine speed of 1600 rpm, full load, and optimal injection and ignition timings, methanol engine can obtain shorter ignition delay, lesser cycle-by-cycle variation, the maximum in-cylinder pressure, the maximum heat release rate, and higher thermal efficiency compared to the case of non-optimized injection and ignition timings. For methanol engine, the optimization of injection timing and ignition timing can lead to an improvement of brake-specific fuel consumption of more than 10% compared to non-optimized case in the overall load range and engine speed of 1600 rpm. The best compromise between thermal efficiency and exhaust emissions is reached at optimal injection and ignition timings.

Comparison of immunotoxic effects induced by the extracts from methanol and gasoline engine exhausts in vitro

Gasoline engine exhaust has been considered as a major source of air pollution in China. Due to lower cyto- and geno-toxicity effects of methanol engine exhaust, methanol is regarded as a potential substitute for gasoline. We have previously compared cyto- and geno-toxicities of gasoline engine exhaust with that of methanol engine exhaust in A549 cells (Zhang et al., 2007).To characterize the immunotoxic effects for gasoline and methanol engine exhausts in immune cell, in this study, we further compared effects of gasoline and methanol engine exhausts on immune function in RAW264.7 cell and rabbit alveolar macrophages. Results showed that both gasoline and methanol engine exhaust could evidently inhibit RAW264.7 cell proliferation, promote RAW264.7 cell apoptosis, decrease E-rosette formation rate and inhibit anti-tumor effects of alveolar macrophages, at the same time, these effects of gasoline engine exhaust were far stronger than those of methanol engine exhaust. In addition, gasoline engine exhaust could significantly inhibit activities of ADCC of alveolar macrophages, but methanol engine exhaust could not. These results suggested that both gasoline and methanol engine exhausts might be immunotoxic atmospheric pollutants, but some effects of gasoline engine exhaust on immunotoxicities may be far stronger than that of methanol engine exhaust.

Emissions of Formaldehyde and Unburned Methanol from a Spark-Ignition Methanol Engine during Cold Start

The effects of the methanol injection quantity per cycle, the ignition timing, the methanol injection timing, the additional liquefied petroleum gas (LPG) injected into the inlet port, and the LPG ...

401 燃料の衝突・分散(OSKA)方式を用いた直接噴射式メタノール機関の性能向上に関する研究 : 最適燃料噴射開弁圧の検討(OS4-1 環境に対応するエンジンシステムI,オーガナイズドセッション:4 環境に対応するエンジンシステム)

401 燃料の衝突・分散(OSKA)方式を用いた直接噴射式メタノール機関の性能向上に関する研究 : 最適燃料噴射開弁圧の検討(OS4-1 環境に対応するエンジンシステムI,オーガナイズドセッション:4 環境に対応するエンジンシステム)

Development of a direct-injection stratified-charge methanol engine

On the basis of the wall-guided, spray-guided, and air-guided technologies related to gasoline direct-injection spark-ignition (DISI) engines, a complex-guided stratified-charge combustion system for a methanol DISI engine was developed. The test engine was a retrofitted four-cylinder diesel engine. The key parameters were optimized numerically and experimentally, such as the location of the swirl deflector, the spatial location of spray, the swirl ratio, the injection and ignition timings, and the needle valve opening pressure. The results show that the direct-injection stratified-charge (DISC) methanol engine can work with an excessive air ratio λ as high as 2.23, and its brake thermal efficiency reaches 29.7 per cent at a speed of 1500r/min, and a brake mean effective pressure of 0.45MPa. The DISC methanol engine exhibits relatively good performance with little cyclic variations, although it is sensitive to induction swirl. The test results indicate that the matching principle is successful. The developed DISC methanol engine can run under variable induction swirl to meet the requirement of stratification combustion under different engine speed operating conditions.

Combustion of a Spark-Ignition Methanol Engine during Cold Start under Cycle-by-Cycle Control

The effects of ambient temperature, intake air preheating, additional liquefied petroleum gas (LPG) injected into the inlet port, and methanol injection timing on the cold-start first cycle firing behavior of an electronically controlled inlet port methanol injection spark-ignition (SI) engine were investigated under a single-cycle fuel injection strategy. The results showed that the ambient temperature significantly affects the start firing behavior of the engine. When the ambient temperature is below 16 °C, the methanol engine can not be started reliably without auxiliary start aids even at the large amount of methanol injected per cycle. Using a glow plug to heat the engine inlet manifold and additional LPG injected into the inlet port result in a reliable firing of the engine. The amount of methanol injected per cycle for the reliable firing during the cold start of the engine reduces obviously, and the cold-start performance improves significantly with the rise in ambient temperature. If the fuel inj...

Comparison of cytotoxicity and genotoxicity induced by the extracts of methanol and gasoline engine exhausts

Gasoline engine exhaust has been considered a major source of air pollution in China, and methanol is considered as a potential substitute for gasoline fuel. In this study, the genotoxicity and cytotoxicity of organic extracts of condensate, particulate matters (PM) and semivolatile organic compounds (SVOC) of gasoline and absolute methanol engine exhaust were examined by using MTT assay, micronucleus assay, comet assay and Ames test. The results have showed that gasoline engine exhaust exhibited stronger cytotoxicity to human lung carcinoma cell lines (A549 cell) than methanol engine exhaust. Furthermore, gasoline engine exhaust increased micronucleus formation, induced DNA damage in A549 cells and increased TA98 revertants in the presence of metabolic activating enzymes in a concentration-dependent manner. In contrast, methanol engine exhaust failed to exhibit these adverse effects. The results suggest methanol may be used as a cleaner fuel for automobile.

K-2028 減圧沸騰燃料噴射による希薄予混合自己着火メタノールエンジンの燃焼改善(S26-5 DME・メタノール・燃料性状・燃料設計)(S26 新燃料,新燃焼,新原動機)

The problems of the premixed charge compression ignition methanol combustion system are that the brake thermal efficiency decreases, and CO and THC emissions increase due to a deterioration of high load combustion. The purpose of this study is to improve the high load combustion of a premixed charge compression ignition methanol engine using a flash boiling fuel injection technique. The results of this study have shown that the premixed charge compression ignition methanol combustion system using a flash boiling fuel injection technique increases the brake thermal efficiency, decreases CO and THC emissions, while maintaining low NOx emissions in the high load region. Particularly, when the brake specific energy consumption was 10 MJ/kWh at high load operation, NOx emissions decreased to as low as 3 g/kWh.

Removal of Unburned Species in Simulated Methanol Engine Exhaust Gas with NO<SUB>x</SUB> Purification Catalyst

Removal of Unburned Species in Simulated Methanol Engine Exhaust Gas with NO<SUB>x</SUB> Purification Catalyst

Engine Performance and Combustion Characteristics in a Direct-Injection Methanol Engine with Supercharging.

Effects of supercharging on a engine performance and exhaust emissions in a spark-assisted direct injection methanol engine were investigated under heavy load conditions. The test results indicated that the supercharging has the effects of improving thermal efficiency, CO and NOx emissions. The combustion analyses showed that the supercharging suppress a rapid combustion of stratified mixture which include fuel spray drop, and makes contributions to promote premixture with rapid fuel spray evaporating and fuel-air mixing. As a result, supercharging increased heat release during the premixed combustion. In addition, increasing of premixed combustion with the supercharging reduced the deterioration of brake thermal efficiency during the EGR under heavy load conditions. The supercharging with EGR can significantly reduce the NOx emissions while keeping the high thermal efficiency as direct injection diesel engines.

Study of glow plug assisted direct injection methanol engine with a three-dimensional diffusing spray (NICS-MH) ? The effect of glow plug location and squish area to engine performance and exhaust emissions Kazumasa Urushihara, Kyoko Okamoto (Nippon Institute of Technology Graduate School), Masaru Ogura (Nippon Institute of Technology)

Study of glow plug assisted direct injection methanol engine with a three-dimensional diffusing spray (NICS-MH) ? The effect of glow plug location and squish area to engine performance and exhaust emissions Kazumasa Urushihara, Kyoko Okamoto (Nippon Institute of Technology Graduate School), Masaru Ogura (Nippon Institute of Technology)

Simulation of catalytic reaction of methanol engine exhaust emissions

Simulation of catalytic reaction of methanol engine exhaust emissions

Effects of EGR on Combustion and Exhaust Gas in a Direct-Injection Methanol Engine.

An EGR was applied in a spark-assisted, direct-injection (DI) neat methanol engine. An experimental study has been carried out to analyze effects of EGR that influence brake thermal efficiency and NOx emission. The EGR on the DI methanol engine alters charge, in particular by decreasing the concentration of oxygen and increasing the concentration of unburned methanol with high charge temperature. The results of qualitative analyses show that methanol vaporization suppresses heat-release at the initial combustion stage, therefore inducing the high heat-release rates characteristics of following stages such as premixed combustion. The unburned methanol in charge was useful for the flame development during spark discharge in lower oxygen atmosphere. It was found that the brake thermal efficiency of the methanol engine with the EGR was improved almost the same as that of diesel engines at low load. NOx emissions were lower at low load by lowering the combustion temperature in the cylinders.

Combustion control of direct injection methanol engine using a combination of charge heating and exhaust gas recirculation

The feasibility of a highly efficient, low-NOx spark-assisted direct injection methanol engine has been investigated using a combination of charge heating and EGR under light load conditions. The results show that, as the charge temperature is increased, rapid premixed combustion initiated by spark ignition occurs and self-ignition of subsequent fuel spray is induced. Thus the combustion progresses rapidly in a stable state, improving the brake thermal efficiency. It was found that the oxygen concentration in the charge can be reduced by conducting EGR at high rate under high charge temperature, so that effective NOx reduction is possible.

Simulation about catalyst reaction on methanol engine exhaust gas

Simulation about catalyst reaction on methanol engine exhaust gas