Nitric-Oxide Generation in a Simulated Spark-Ignition Engine

1971 ◽  
Vol 93 (2) ◽  
pp. 432-436
Author(s):  
J. L. Hodges ◽  
R. F. McAlevy ◽  
J. H. Potter

Nitric oxide emitted from the exhaust of spark-ignition automotive engines has long been recognized as a contributor to air pollution. A mechanical analog for the spark-ignition engine was designed, instrumented, and tested. Product gas concentrations of nitric oxide were monitored in the analog, using an ultraviolet absorption technique. Nitric oxide concentrations were found to be independent of the rate at which product gases were expanded.

2017 ◽  
Vol 168 (1) ◽  
pp. 122-124
Author(s):  
Marek BRZEŻAŃSKI ◽  
Michał MARECZEK ◽  
Marek SUTKOWSKI ◽  
Wojciech SMUGA

Huge amount of by-products is still considered as waste and is simply disposed, for example by-product gas is usually flared. Political and social pressure to reduce air pollution and national needs for energy security make these waste fuels interesting for near-future power generation. Unfortunately most of these waste fuels, even when liquefied or gasified, have very low quality and can hardly be used in high-efficiency power systems. Among main challenges are low calorific value and composition fluctuation. Additionally very often there is a high content of sulphur, siloxanes, tars, etc., which have to be removed from the fuel. Modern 4-stroke gas engines designed for power generation applications provide very high efficiency, high reliability and availability. Unfortunately, these gas engines require high quality fuel with stable composition. Horus-Energia together with Cracow University of Technology developed a novel gas supply system HE-MUZG that can adapt to current gas quality and change engine settings accordingly.This article will present results from the HE-MUZG system tests on modern 4-stroke spark-ignition gas engine. Tests focus on low quality gas, such as gas with low calorific value, gas with very low methane number and gas with very big variations of calorific value. Test results compared with performance of that engine in the original configuration show huge improvements. Moreover the HE- MUZG system is easy to implement in commercial gensets.


Author(s):  
Jerald A. Caton

The use of either hydrogen or isooctane for a spark-ignition engine was examined using a thermodynamic cycle simulation including the second law of thermodynamics. The engine studied was a 5.7 liter, automotive engine operating from idle to wide open throttle. The hydrogen or isooctane was assumed premixed with the air. Two features of hydrogen combustion that were included in the study were the higher flame speeds (shorter burn durations) and the wider lean flammability limits (lean equivalence ratios). Three cases were considered for the use of hydrogen: (1) standard burn duration and an equivalence ratio of 1.0, (2) a shorter burn duration and an equivalence ratio of 1.0, and (3) a shorter burn duration and variable, lean equivalence ratios. The results included thermal efficiencies, other performance metrics, second law parameters, and nitric oxide emissions. In general, for the cases with an equivalence of 1.0, the brake thermal efficiency was slightly lower for the hydrogen cases due to the higher temperatures and higher heat losses. For the variable, lean equivalence ratio cases, the thermal efficiency was higher for the hydrogen case relative to the isooctane case. Due to the higher temperatures, the hydrogen cases had over 50% higher nitric oxide emissions compared to the isooctane case at the base conditions. In addition, the second law analyses indicated that the destruction of availability during the combustion process was lower for the base hydrogen case (11.2%) relative to the isooctane case (21.1%).


2021 ◽  
Vol 13 (16) ◽  
pp. 9229
Author(s):  
Ming-Hsien Hsueh ◽  
Chao-Jung Lai ◽  
Meng-Chang Hsieh ◽  
Shi-Hao Wang ◽  
Chia-Hsin Hsieh ◽  
...  

The exhaust emissions from Internal Combustion Engines (ICE) are currently one of the main sources of air pollution. This research presented a method for improving the exhaust gases and the performance of a Spark-Ignition (SI) engine using a water vapor injection system and a Non-Thermal Plasma (NTP) system. These two systems were installed on the intake manifold to investigate their effects on the engine’s performance and the characteristics of exhaust emission using different air/fuel (A/F) ratios and engine speeds. The temperatures of the injected water were adjusted to 5 and 25 °C, using a thermoelectric cooler (TEC) temperature control device. The total hydrocarbons (HC), nitrogen oxide (NOx), and engine torque were measured at different A/F ratios and engine speeds. The results indicated that the adaptation of the water vapor injection system and NTP system increased the content of the combustibles and combustion-supporting substances while achieving better emissions and torque. According to the test results, while the engine torque under 25 °C water+NTP was raised to 7.29%, the HC under 25 °C water+NTP and the NOx under 25 °C water were reduced to 16.31% and 11.88%, respectively. In conclusion, the water vapor injection and the NTP systems installed on the intake manifold could significantly reduce air pollution and improve engine performance for a more sustainable environment.


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