Relation between Power and Exhaust Gas Composition of Micro Combustion Engine

2004 ◽  
Vol 2004.41 (0) ◽  
pp. 255-256
Author(s):  
Takahiro SASAKI ◽  
Hiroshi ENOMOTO
Author(s):  
Stefan Klinkert ◽  
John W. Hoard ◽  
Sakthish R. Sathasivam ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac

In recent years, diesel exhaust gas aftertreatment has become a core combustion engine research subject because of both increasingly stringent emission regulations and incentives toward more fuel-efficient propulsion systems. Lean NOX traps (LNT) and selective catalytic reduction (SCR) catalysts represent two viable pathways for the challenging part of exhaust gas aftertreatment of lean burn engines: NOX abatement. It has been found that the combination of LNT and SCR catalysts can yield synergistic effects. Switches in the operation mode of the engine, temporarily enriching the mixture, are required to regenerate the LNT catalyst and produce ammonia for the SCR. This paper describes the design of a catalyst flow reactor that allows studying multi-brick catalyst systems using rapid exhaust gas composition switches and its initial validation. The flow reactor was designed primarily to study the potential of combining different aftertreatment components. It can accommodate two sample bricks at a time in two tube furnaces, which allows for independent temperature control. Moreover, the flow reactor allows for very flexible control of the composition and flow rate of the synthetic exhaust, which is blended using mass flow controllers. By using a two-branch design, very fast switches between two exhaust gas streams, as seen during the regeneration process of a LNT catalyst, are possible. The flow reactor utilizes a variety of gas analyzers, including a 5-Hz FTIR spectrometer, an emissions bench for oxygen and THC, a hydrogen mass spectrometer, and gas chromatographs for HC speciation. An in-house control program allows for data recording, flow reactor control, and highly flexible automation. Additionally, the hardware and software incorporate features to ensure safe testing. The design also has provisions for engine exhaust sampling.


Author(s):  
Helmer G. Andersen ◽  
Pen-Chung Chen

Computing the solution to the energy balance around a gas turbine in order to calculate the intake mass flow and the turbine inlet temperature requires several iterations. This makes hand calculations very difficult and, depending on the software used, even causes significant calculation times on PCs. While this may not seem all that important considering the power of today’s personal computers, the approach described in this paper presents a new way of looking at the gas turbine process and the resulting simplifications in the calculations. This paper offers a new approach to compute the energy balance around a gas turbine. The energy balance requires that all energy flows going into and out of the control volume be accounted for. The difficulty of the energy balance equation around a gas turbine lies in the fact that the exhaust gas composition is unknown as long as the intake flow is unknown. Thus, a composition needs to be assumed when computing the exhaust gas enthalpy. This allows the calculation of the intake flow, which in turn provides a new exhaust gas composition, and so forth. By viewing the exhaust gas as a flow consisting of ambient air and combusted fuel, the described iteration can be avoided. The study presents the formulation of the energy balance applying this approach and looks at the accuracy of the result as a function of the inaccuracy of the input parameters. Furthermore, solutions of the energy balance are presented for various process scenarios, and the impact of the uncertainty of key process parameter is analyzed.


2011 ◽  
Vol 63-64 ◽  
pp. 237-240
Author(s):  
Qi Xin Sun ◽  
Limin Chen

In recent years, the internal combustion engine has been widely used through technological advances to improve its environmental performance. Mechanical and electrical integration of the engine turbocharging system is based on conventional turbocharging system to increase motor in parallel with the turbocharger and the corresponding reversible energy storage components, so that achieve by adjusting the energy input or output direction and the size of the motor to adjust the exhaust turbocharger operating point and the gas supply function. According to matching requirements of light vehicle diesel engine, the analysis model of exhaust gas energy is obtained through qualitative analysis of exhaust gas energy in turbocharged diesel engine.


2019 ◽  
Vol 179 (4) ◽  
pp. 204-209
Author(s):  
Winicjusz STANIK ◽  
Jerzy CISEK

To avoid the negative effects of increasing the amount of RME in the diesel fuel (to 10%), three different additive packages were used: stabilising, cleaning, and increasing the cetane number with different concentrations. The tests were carried out using a 4-cylinder, turbocharged 1.9 TDI engine from VW. The tests were carried out for 4 fuels (comparative fuel with a content of 7% RME and 3 test fuels with a content of 10% RME, differing in the content of the additive package.It was found that each of the 3 additive packages used does not have a significant impact on fuel consumption. However, a different effect of the tested additives on the composition of exhaust gases was observed. The first package had a slight effect on reducing the NOx concentration in the exhaust, but only for small engine loads. On the other hand, the second additive pack worked more effectively only at higher engine loads (in relation to the reduction of NOx concentration in the exhaust gases). In the third packet, the amount of the cetane additive was doubled (compared to the second packet). Then, the reduction in the NOx concentration in the exhaust gas by 3–8% was obtained with reference to the comparative fuel.


Author(s):  
Hanna Sara ◽  
David Chalet ◽  
Mickaël Cormerais

Exhaust gas heat recovery is one of the interesting thermal management strategies that aim to improve the cold start of the engine and thus reduce its fuel consumption. In this work, an overview of the heat exchanger used as well as the experimental setup and the different tests will be presented first. Then numerical simulations were run to assess and valorize the exhaust gas heat recovery strategy. The application was divided into three parts: an indirect heating of the oil with the coolant as a medium fluid, a direct heating of the oil, and direct heating of the oil and the coolant. Different ideas were tested over five different driving cycles: New European driving cycle (NEDC), worldwide harmonized light duty driving test cycle (WLTC), common Artemis driving cycle (CADC) (urban and highway), and one in-house developed cycle. The simulations were performed over two ambient temperatures. Different configurations were proposed to control the engine's lubricant maximum temperature. Results concerning the temperature profiles as well as the assessment of fuel consumption were stated for each case.


2019 ◽  
Vol 113 ◽  
pp. 03020
Author(s):  
Vittorio Usai ◽  
Silvia Marelli ◽  
Avinash Renuke ◽  
Alberto Traverso

The reduction of CO2 and, more generally, GHG (Green House Gases) emissions imposed by the European Commission (EC) and the Environmental Protection Agency (EPA) for passenger cars has driven the automotive industry to develop technological solutions to limit exhaust emissions and fuel consumption, without compromising vehicle performance and drivability. In a mid-term scenario, hybrid powertrain and Internal Combustion Engine (ICE) downsizing represent the present trend in vehicle technology to reduce fuel consumption and CO2 emissions. Concerning downsizing concept, to maintain a reasonable power level in small engines, the application of turbocharging is mandatory for both Spark Ignition (SI) and Diesel engines. Following this aspect, the possibility to recover the residual energy of the exhaust gases is becoming more and more attractive, as demonstrated by several studies around the world. One method to recover exhaust gas energy from ICEs is the adoption of turbo-compounding technology to recover sensible energy left in the exhaust gas by-passed through the waste-gate valve. In the paper, an innovative option of advanced boosting system is investigated through a bladeless micro expander, promising attractive cost-competitiveness. The numerical activity was developed on the basis of experimental data measured on a waste-gated turbocharger for downsized SI automotive engines. To this aim, mass flow rate through the by-pass valve and the turbine impeller was measured for different waste-gate settings in steady-state conditions at the turbocharger test bench of the University of Genoa. The paper shows that significant electrical power can be harvested from the waste-gate gases, up to 94 % of compressor power, contributing to fuel consumption reduction.


1989 ◽  
Vol 111 (3) ◽  
pp. 410-423 ◽  
Author(s):  
J. Myers ◽  
M. Myers ◽  
P. Myers

This paper presents a calculation technique and related computer program to yield mass emission rates from measured exhaust gas composition and fuel flow rate or fuel plus air flow rate (if air flow rate is measured). The sensitivity of the computed emission rates to (1) the method of calculation and (2) experimental measurement errors is investigated. It is recommended that published emission rates be the average of the rates computed by several different methods, as discussed in this paper, to minimize the effect of experimental variations in measurement. This, plus use of the computer program presented, would standardize the assumptions used in computing emissions and minimize differences in reported emission rates from different laboratories.


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