Secondary air injection

About: Secondary air injection is a research topic. Over the lifetime, 11452 publications have been published within this topic receiving 112147 citations.

Fuel injection system and control method

Abstract: A fuel injection valve driving method includes control of an overexciting current and a holding current supplied to the fuel injection valve in accordance with a target fuel supply pressure as obtained from an operating condition. Thereby the opening and holding of the open position of the fuel injection valve is controlled.

NOx Removal from Diesel Engine Exhaust by Ozone Injection Method

Abstract: Abstract NOx removal method by non-thermal discharge has some problems like contamination of reactor by soot and low energy efficiency to reduce NOx. The energy efficiency of NO removal is known as around 20g/kWh, but it decreases at higher NO oxidation rate. This degradation comes from the reverse reaction of NO2 to NO by 0 radicals. In this paper, NO removal by ozone injection is reported. This method is free from both contamination by soot and the degradation of NO removal efficiency at higher NO removal rate. The experiments were carried out using 2.4 KVA diesel engine exhaust gases. The energy efficiency obtained by ozone injection method is 25g/kWh, which is fairly good in comparison with direct discharge method. It was also confirmed that there is no degradation of efficiency up to more than 90% removal. These results are discussed by calculations of chemical reactions.

Exhaust gas control valve

Abstract: An exhaust gas control valve is provided with a first and second valve bodies and valve seats and a bellows member made of fluoric synthetic resin for segregating a diaphragm and a shaft guiding bush from exhaust gas to secure the operation of the control valve without being affected by the exhaust gas thereby to enhance durability of the control valve.

Combustion engine of turbocompound type with exhaust gas brake

Abstract: The invention relates to a combustion engine 7 of compound type in which the exhaust gases partly drive a first turbine 3 for driving a compressor 4 for supplying and compressing combustion air, partly a second turbine 2 which, via a mechanical transmission 1 transmits the residual energy in the exhaust gases to the crankshaft 10 of the combustion engine. The exhaust gas brake 6 being placed downstream, in the exhaust gas flow direction, after the second power turbine 2 results in a greatly increased braking effect at a given limited permitted exhaust gas temperature. In corresponding conditions with regard to exhaust gas temperature and type of exhaust gas brake damper the braking effect extracted for compound engines can be improved by up to 27% compared with a conventional supercharged diesel engine.

Optimisation and evaluation of NTU and effectiveness of a helical coil tube heat exchanger with air injection

Abstract: Air bubble injection has recently been confirmed as a beneficial technique for enhancing the thermal performance of a heat exchanger. The normal vertical motion of the bubbles due to buoyancy force leads to the entrainment of fluid from the shell side, thereby raising its velocity and turbulence level whilst improving the mix within the shell. Consequently, the thermal boundary layer that formed around the outer surface of the coil is disrupted, thus reducing heat transfer resistance and enhancing the heat transfer rate. Despite relatively considerable attention that has been given to assess this technique, numerous investigations have concentrated on only a few operational conditions. This consideration will be insufficient to understand the influence of air injection entirely on the thermal performance of a heat exchanger. Thus, this study aims to fill this gap by performing experiments over numerous operational conditions for hot and cold fluids and the injected air in a vertical counter-current coiled tube heat exchanger. The optimal air flow and the shell-side flow rates of the vertical coiled tube heat exchanger are determined, thus leading to the economic operation of a heat exchanger. Therefore, the implemented shell-side flow, air flow and coil-side flow rates were changed from 2 LPM to 10 LPM, from 0 to 10 LPM and from 1 LPM to 2 LPM, respectively, with three temperature differences (i.e., 20 ° C , 30 ° C a n d 36 ° C ). The number of heat transfer units (NTU) and the thermal effectiveness of the heat exchanger were investigated intensively. Results showed that the NTU and the effectiveness are influenced significantly by the injected air flow, shell-side flow and coil-side flow rates without noticeable effect on the temperature difference. In addition, the positive role of the injected air flow rate was diminished, and no further enhancement of NTU and effectiveness was observed when Q a > 6 L P M . The most effective shell-side flow rate was also 6 LPM. The maximum augmentation in the NTU and the effectiveness were 1.93 and 0.83, correspondingly, whilst the minimum value of the NTU and the effectiveness were 0.66 and 0.63, respectively.