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Showing papers on "Secondary air injection published in 2016"


Journal ArticleDOI
TL;DR: In this article, the operating range and wave speed performance of a Rotating Detonation Combustor (RDC) was characterized for hydrogen-air mixtures for three fuel injection schemes and two air injection schemes.

132 citations



Journal ArticleDOI
TL;DR: In this paper, the behavior of the oxidizer inlet and the fuel injection plenums during the operation of a Rotating Detonation Combustor (RDC) was studied using pressure sensors in the air injection gap, the fuel plenum, and in the combustor.

62 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of air injection into clay-soil, with and without a perforated sphere around the dripper, on oxygen concentrations and pepper yields in a barrel experiment, and on soil oxygen concentration and stem growth of young mango trees in a field experiment.

45 citations


Journal ArticleDOI
TL;DR: In this paper, an overhead four-valve spark-ignition gasoline engine was modified to run in the two-stroke cycle, and the scavenging process took place during a long valve overlap period around bottom dead centre at each crankshaft revolution.

40 citations


Journal ArticleDOI
TL;DR: The results indicate that air injection improves cookstove performance and reduces total PM mass but increases total ultrafine PM concentration over the course of high-power cooking.
Abstract: In order to address the health risks and climate impacts associated with pollution from cooking on biomass fires, researchers have focused on designing new cookstoves that improve cooking performance and reduce harmful emissions, specifically particulate matter (PM). One method for improving cooking performance and reducing emissions is using air injection to increase turbulence of unburned gases in the combustion zone. Although air injection reduces total PM mass emissions, the effect on PM size distribution and number concentration has not been thoroughly investigated. Using two new wood-burning cookstove designs from Lawrence Berkeley National Laboratory, this research explores the effect of air injection on cooking performance, PM and gaseous emissions, and PM size distribution and number concentration. Both cookstoves were created using the Berkeley-Darfur Stove as the base platform to isolate the effects of air injection. The thermal performance, gaseous emissions, PM mass emissions, and particle concentrations (ranging from 5 nm to 10 μm in diameter) of the cookstoves were measured during multiple high-power cooking tests. The results indicate that air injection improves cookstove performance and reduces total PM mass but increases total ultrafine (less than 100 nm in diameter) PM concentration over the course of high-power cooking.

39 citations


Journal ArticleDOI
TL;DR: In this paper, the mixing performance and non-reacting injection flow field within a rotating detonation engine was analyzed. But, the three-dimensional baseline geometry produces poor hydrogen/air mixing in the injection zone due to low fuel penetration into the wide, cross-flowing air stream and low air entrainment into the vortex structure.

37 citations


Journal ArticleDOI
TL;DR: In this article, the effect of air-water two-phase flow patterns and phase interaction on the performance of air lift pumps was investigated and the results showed that the performance does not only depend on the design of air injector, but also on the dynamics of air injection method.

36 citations


Journal ArticleDOI
15 May 2016-Fuel
TL;DR: In this article, the authors used the reservoir simulation approach to study air injection in a light oil reservoir and found that the oil recovery factor is sensitive to O 2 content in air and geological structure of the reservoir.

33 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented a systematic study of split injection combined with Miller cycle in large-bore engines and found that the pilot injection reduced the ignition delay but dropped the peak of the premixed combustion only with the most advanced intake valve closing.

33 citations


Journal ArticleDOI
TL;DR: In this paper, a numerical study of a medium size model of industrial gas turbine combustor was conducted using the RANS (Reynolds Averaged Navier-Stokes) approach with k − ∊ model and LES (Large Eddy Simulation) with WALE (Wall Adapting Local Eddy viscosity) subgrid model.

Journal ArticleDOI
01 Mar 2016
TL;DR: In this paper, the effect of cylinder throttling on exhaust gas temperatures, fuel consumption, in-cylinder combustion and emissions was analyzed, and a significant increase in turbine outlet temperature accompanied by a decrease in fuel consumption and NOx and particulate matter emissions was observed.
Abstract: Most diesel engines meet today’s strict NOx and particulate matter emission regulations using after-treatment systems. A major drawback of these after-treatment systems is that they are efficient in reducing emissions only when their catalyst temperature is within a certain range (typically between 250 °C and 450 °C). At lower engine loads this is a major problem as the exhaust temperatures are usually below 250 °C. The primary objective of this study was to analyze “cylinder throttling” via both delayed and advanced intake valve closure timing. The effect of cylinder throttling on exhaust gas temperatures, fuel consumption, in-cylinder combustion and emissions is outlined. A significant increase in turbine outlet temperature accompanied by a decrease in fuel consumption, NOx, and particulate matter emissions was observed. Both delayed and advanced intake valve closure timings were equally effective. The increase in exhaust gas temperatures was attributed to a drop in air flow through the engine, which r...

Patent
10 Feb 2016
TL;DR: A heat exchanger with thermal energy recovery for an exhaust system (H) of an internal combustion engine (A) is described in this paper, which defines a plurality of corresponding flowing channels for the exhaust gases.
Abstract: A heat exchanger (10) with thermal energy recovery for an exhaust system (H) of an internal combustion engine (A); the heat exchanger (10) having a plurality of pipes (22), which defines a plurality of corresponding flowing channels for the exhaust gases; a wall (23) of each pipe (22) is internally coated with a coating layer (24) consisting of a material with an exothermic hygroscopy, namely a material that is hygroscopic and has an exothermic water absorption process.

Patent
29 Jan 2016
TL;DR: In this paper, methods and systems for EGR heat recovery at an exhaust gas heat exchanger are described. But the authors do not consider the EGR recovery from the exhaust manifold.
Abstract: Methods and systems are provided for exhaust gas heat recovery at an exhaust gas heat exchanger. Exhaust gas may flow in both directions through an exhaust bypass passage and the heat exchanger coupled to the bypass passage. Hot or cold EGR may be delivered from the exhaust passage to the engine intake manifold and heat from the exhaust gas may be recovered at the heat exchanger.

Journal ArticleDOI
01 Jan 2016-Energy
TL;DR: In this paper, the authors used a reproducing PCB (pulverized coal boiler) environment to evaluate the potential of sorbent co-firing and waste cocombustion as cheap retrofitting techniques to reduce SO 2 emissions of existing boiler.

Journal ArticleDOI
TL;DR: In this article, an experimental facility is implemented with the aim of improving the performance of internal combustion engines working at low ambient temperatures, an exhaust heat recovery system for a diesel engine has been proposed as a solution to cold operation negative effects.

Journal ArticleDOI
TL;DR: In this paper, an experimental investigation was conducted to assess the combustion and emissions of a single-cylinder diesel engine using water injection in the exhaust manifold and the results showed that water injection leads to increase in the cylinder pressure, apparent heat release rate (AHRR) in premixed combustion phase and, the ignition delay comparing with EGR without water injection.

Journal ArticleDOI
01 Sep 2016-Fuel
TL;DR: In this article, the authors proposed low temperature air-solvent injection (LTASI) as an alternative process to overcome this problem, which involved oxygen addition reactions rather than bond scission reactions (in situ combustion).

Journal ArticleDOI
TL;DR: This article investigates groundwater mixing and contaminant removal efficiency in different injection modes (i.e., continuous and pulsed), and compares them to those achieved in a third mode, which is denote as "rate changing," where injection is always on, and its rate is varying with time by abrupt changes.
Abstract: Air sparging (AS) is a commonly applied method for treating groundwater contaminated with volatile organic compounds (VOCs). When using a constant injection of air (continuous mode), a decline in remediation efficiency is often observed, resulting from insufficient mixing of contaminants at the pore scale. It is well known that turning the injection on and off (pulsed mode) may lead to a better remediation performance. In this article, we investigate groundwater mixing and contaminant removal efficiency in different injection modes (i.e., continuous and pulsed), and compare them to those achieved in a third mode, which we denote as "rate changing." In this mode, injection is always on, and its rate is varying with time by abrupt changes. For the purpose of this investigation, we conducted two separate sets of experiments in a laboratory tank. In the first set of experiments, we used dye plume tracing to characterize the mixing induced by AS. In the second set of experiments, we contaminated the tank with a VOC and compared the remediation efficiency between the different injection modes. As expected, we observed that time-variable injection modes led to enhanced mixing and contaminant removal. The decrease in contaminant concentrations during the experiment was found to be double for the "rate changing" and "pulsed" modes compared to the continuous mode, with a slightly preferable performance for the "rate changing" mode. These results highlight the critical role that mixing plays in AS, and support the need for further investigation of the proposed "rate changing" injection mode.

Journal ArticleDOI
Jaeheun Kim1, Choongsik Bae1
01 May 2016
TL;DR: In this article, the effects of late intake valve closing and exhaust gas recirculation on the emissions and engine performance of a single-cylinder diesel research engine were observed using two cam profiles (symmetric and asymmetric) implemented using an offset angle at various injection valve closing timings to characterize the engine performance and the emissions.
Abstract: The effects of late intake valve closing and exhaust gas recirculation on the emissions and the engine performance of a single-cylinder diesel research engine were observed. Two cam profiles (symmetric and asymmetric) were implemented using an offset angle at various intake valve closing timings to characterize the engine performance and the emissions. The injection timings were swept at every condition to evaluate the optimal operating conditions. The highest indicated mean effective pressure was observed once the combustion phasing was tuned to the optimum crank angle (in degrees) by varying the injection timing. The indicated mean effective pressure exhibited a slight penalty when both exhaust gas recirculation and late intake valve closing were used in comparison with the base intake valve closing timing with no exhaust gas recirculation. However, an appropriate combination of the exhaust gas recirculation with late intake valve closing was effective in reducing the nitrogen oxide emissions owing to t...

Patent
12 Feb 2016
TL;DR: In this paper, a deterioration diagnosis device for the exhaust gas purification apparatus in which in a period of time in which inducement processing is carried out which is to induce a water-gas-shift-reaction in a catalyst disposed at the upstream side of the SCR catalyst, is presented.
Abstract: In an deterioration diagnosis device for the exhaust gas purification apparatus in which in a period of time in which inducement processing is carried out which is to induce a water-gas-shift-reaction in a catalyst disposed at the upstream side of the SCR catalyst, by changing an air fuel ratio of exhaust gas discharged from an internal combustion engine from a lean air fuel ratio into a predetermined rich air fuel ratio, an air fuel ratio of exhaust gas flowing into the SCR catalyst and an air fuel ratio of exhaust gas flowing out from the SCR catalyst are measured by the air fuel ratio sensors, respectively, so that deterioration of the SCR catalyst is diagnosed based on a difference between the measured values of these sensors, wherein an end time of the execution of the inducement processing is adjusted in such a manner that an amount of hydrogen oxidized in the SCR catalyst during the period of the execution of the inducement processing becomes constant.

Patent
20 Jan 2016
TL;DR: In this paper, an after-treatment system including an exhaust treatment component provided in an exhaust passage, a tank carrying an aqueous reagent, and an electrochemical cell in communication with the tank was presented.
Abstract: An after-treatment system including an exhaust treatment component provided in an exhaust passage, a tank carrying an aqueous reagent, and an electrochemical cell in communication with the tank and configured to receive the aqueous reagent therefrom. The electrochemical cell is configured to convert the aqueous reagent into a first exhaust treatment fluid and a second exhaust treatment fluid. A controller is in communication with the electrochemical cell. The controller is configured to vary amounts and/or composition of each of the first exhaust treatment fluid and the second exhaust treatment fluid produced by the electrochemical cell. An injector is in communication with the electrochemical cell and the exhaust passage, and is configured to receive one of the first exhaust treatment fluid or the second exhaust treatment fluid from the electrochemical cell, and dose the one exhaust treatment fluid into the exhaust passage at a location upstream from the exhaust treatment component.

Patent
03 Aug 2016
TL;DR: In this article, an engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system in fluid communication with a heat exchanger, an exhaust duct in fluid communications with air passages of the heat exchange, and an intermediate duct in liquid communication with an exhaust of the engine and having an outlet positioned within the exhaust duct downstream of the fan and upstream of the outlet of the exhaust.
Abstract: An engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system in fluid communication with a heat exchanger, an exhaust duct in fluid communication with air passages of the heat exchanger, a fan in fluid communication with the exhaust duct for driving a cooling air flow through the air passages of the heat exchanger and into the exhaust duct, and an intermediate duct in fluid communication with an exhaust of the engine and having an outlet positioned within the exhaust duct downstream of the fan and upstream of the outlet of the exhaust duct. The outlet of the intermediate duct is spaced inwardly from a peripheral wall of the exhaust duct. The engine assembly may be configured as an auxiliary power unit. A method of discharging air and exhaust gases in an auxiliary power unit having an internal combustion engine is also discussed.

Patent
06 Jan 2016
TL;DR: In this paper, a stamping-turbine air injection composite aero-engine is proposed to solve the problems that the existing gas turbine engine is complicated in structure and limited in running speed range, and a ramjet engine cannot voluntarily start, cannot run at low speed, is difficult in cooling, and has higher requirements for the high temperature resistance of a complete machine.
Abstract: The invention discloses a stamping-turbine air injection composite aero-engine and aims to solve the problems that the existing gas turbine engine is complicated in structure and limited in running speed range, and a ramjet engine cannot voluntarily start, cannot run at a low speed, is difficult in cooling, and has higher requirements for the high temperature resistance of a complete machine. The stamping-turbine air injection composite aero-engine comprises a stamping air inflow cone, an outer duct engine case, an inlet guide blade, a liquid oxygen regulating valve, a liquid nitrogen regulating valve, an inner duct engine case, a rectifying blade, a fuel oil regulating valve, a centrifugal compressor, a diffuser, a combustor, a concentric shaft, a worm wheel, an inner duct rectifying nozzle, a starting dynamo and the like. The stamping-turbine air injection composite aero-engine effectively utilizes the stamping effect and advantages of a turbojet engine, participates in precooling treatment, effectively solves the problems that the ramjet engine takes air in the starting and high-speed states, and the engine power is limited, is simple in structure, low in cost, high in efficiency, wide in running speed range and low in running speed of the complete machine, and has a better application prospect.

Patent
12 Oct 2016
TL;DR: In this article, an enhanced vapor injection air conditioning system consisting of an indoor heat exchanger, an outdoor heat exchange, a compressor and a four-way reversing valve is presented.
Abstract: The invention discloses an enhanced vapor injection air conditioning system. The enhanced vapor injection air conditioning system comprises an indoor heat exchanger, an outdoor heat exchanger, a compressor and a four-way reversing valve. The compressor comprises a liquid storage tank and is provided with an exhaust port, an air make-up port and an air suction port. The liquid storage tank is provided with an air returning port and the air returning port communicates with the air suction port. The four-way reversing valve comprises a first end, a second end, a third end and a forth end. The first end communicates with the exhaust port of the compressor, the second end is connected with an inlet of the indoor heat exchanger, the third end is connected with an outlet of the outdoor heat exchanger and the forth end communicates with the air returning port. The enhanced vapor injection air conditioning system further comprises a bypass circuit. The bypass circuit is connected between the exhaust port of the compressor and the outdoor heat exchanger. The bypass circuit comprises a control valve. The invention further discloses a defrosting control method of the enhanced vapor injection air conditioning system. According to the defrosting control method, the heating effect would not be affected, not only that but the indoor environment temperature can be stabilized and the reversing motion of the four-way reversing valve can be reduced, so that the reliability of equipment and the use comfort of a user can be improved.

Patent
21 Mar 2016
TL;DR: In this article, a throttle body with four main bores, each with a throttle plate and an associated fuel injector, is used to inject fuel into a circular fuel distribution ring via a fuel injection conduit.
Abstract: A throttle body fuel injection system and method that is arranged to easily replace four-barrel carburetors includes a throttle body assembly with four main bores, each with a throttle plate and an associated fuel injector. Each injector feeds fuel into a circular fuel distribution ring via a fuel injection conduit, which introduces pressurized fuel into the air stream. The fuel distribution rings and bores have profiles that avoid constrictions for to prevent low pressure zones according to the Venturi effect. The throttle body includes an idle air control circuit having a port opening into main intake bores downstream of the point of fuel distribution into the air stream, thereby reducing the tendency for a lean fuel mixture at idle. An ECU “feed forward” algorithm controls fuel injection as a function of the position of the idle air control valve.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the safety of exhaust gas in an air injection process for light oil reservoirs, static low-temperature oxidation experiments were carried out on oil samples from a block of the Liaohe oilfield in northeast China.
Abstract: Air injection is a very important technique that is used to enhance the recovery of light oil. To investigate the safety of exhaust gas in an air injection process for light oil reservoirs, static low-temperature oxidation experiments were carried out on oil samples from a block of the Liaohe oilfield in northeast China. The effects of the temperature (80–140 °C) and pressure (10–20 MPa) on the oxygen content of the exhaust gas were studied. It was found that the oxygen consumption rate increases with the temperature. When the temperature rises to 130 °C, the oxygen content in the exhaust gas is much lower than the theoretical calculation of the safe oxygen content, and when the temperature reaches 140 °C, it is nearly exhausted. The effect of the pressure on the oxygen consumption rate is extremely low. Using a component analysis of the crude oil prior to and after the reaction, we observe that aromatic hydrocarbons are barely involved in the reaction at temperatures less than 120 °C. However, when the t...

Journal ArticleDOI
TL;DR: In this paper, a tritium detritiation system (EDS) was proposed for deuterium-deuterium reactions in the core plasma of the Large Helical Device (LHD) and Neutral Beam Injection (NBI).
Abstract: A small amount of tritium is produced by deuterium–deuterium reactions in the core plasma during deuterium plasma experiments conducted in the Large Helical Device (LHD). From the viewpoints of tritium safety handling and public acceptance, any waste gas streams arising from the vacuum vessel of the LHD and Neutral Beam Injection (NBI) system will be treated by an exhaust detritiation system (EDS). The exhaust gas stream produced during the 18th cycle of LHD plasma experiments was observed to design the EDS. The rough pumping gas streams from the LHD and NBIs produced a high flow rate of 300 Nm3/h. The vacuum exhaust gas stream from the LHD had a high hydrogen concentration more than 7% and a flow rate of less than 5 Nm3/h during plasma experiments. The regeneration gas stream of the cryopump systems had a flow rate of more than 5 Nm3/h. Based on these observations, the proposed EDS utilizes two types of tritium recovery system. One comprises two types of catalyst and dual absorbent beds. Other comprises an oxidation catalyst and polymer membrane system.

Journal ArticleDOI
TL;DR: In this article, the conditions under which freely available air at low temperatures and low pressures and in a non-reactive environment may be used for EOR were investigated, and experiments were carried out by injecting air into a lab-scale heavy oil reservoir at different pressures and temperatures in the range of 25-90 °C.
Abstract: Gas-based enhanced oil recovery (EOR) processes rely on the injection of gases, such as carbon dioxide, nitrogen, and natural gas, into heavy oil reservoirs to reduce native oil viscosity. Although these processes are very promising, they face the problem of limited and costly gas supply. This paper investigates the conditions, specifically of temperature variation, under which freely available air at low temperatures and low pressures and in a non-reactive environment may be used for EOR. To that end, experiments are carried out by injecting air into a lab-scale heavy oil reservoir at different pressures (0.169, 0.286, 0.403, and 0.514 MPa absolute) and temperatures in the range of 25–90 °C. Reservoirs of four different permeabilities (40, 87, 204, and 427 darcy) are used in experiments, which demonstrate heavy oil recovery of up to 58.2% original oil in place (OOIP) with constant temperature air injection. When air is injected with a periodic temperature variation between 75 and 90 °C that has an averag...

Patent
14 Dec 2016
TL;DR: In this article, the authors proposed a two-phase flow device for research the enhancement of the natural circulation capacity of a system, which consists of a circulating water system, air bubble generation device, an air supply system and a data acquisition system.
Abstract: The invention provides a two-phase flow device for researching the enhancement of the natural circulation capacity of a system. The two-phase flow device consists of a circulating water system, an air bubble generation device, an air supply system and a data acquisition system, wherein the circulating water system mainly comprises an open type water tank, a filter device, a heat exchanger and other relevant pipelines and valves; the air bubble generation device is a core of the device and consists of an external sleeve and a multiporous medium sleeve; the air supply system mainly comprises an air compressor, an air storage tank and a pressure reducing valve; the data acquisition system mainly consists of an integrated data acquisition system, a high-speed camera system, a gas mass flow meter, an electromagnetic flow meter, a pressure sensor and a temperature sensor. The two-phase flow device can effectively solve the problem of disturbance to a natural circulation system due to active air injection and reduce the additional resistance involved into a circulation loop; the device is simple, easy to operate and uniform in foaming; stable bubble flow can be obtained; the two-phase flow device is favorable for scientific design of natural circulation and two-phase flow and engineering design of a passive safety system.