Exhaust Channel Research Articles

PENGGUNAAN KUNINGAN SEBAGAI BAHAN CATALYTIC CONVERTER TERHADAP EMISI GAS BUANG dan PERFORMA MESIN SUZUKI SHOGUN AXELO 125

The purpose of this study was to determine the use of brass plate catalysts in the exhaust channel of Suzuki Shogun Axelo 125 in 2010. This study used an experimental method. The population in this study was a Suzuki Shogun Axelo 125 motorbike in 2010, the research data was a number showing gas content remove CO2, CO, HC. This research was carried out in the banjarmasin environment office using a gas analyzer and was also conducted at the Banjarmasin plug and play workshop by using a dynamometer. The technique used in data collection was the variation in rpm and number of plates. (1) The results of this study are: Forming a catalytic converter with plate variation 8 (eight) so that the level of CO2 emission reduction is maximum of 52,7%, the level of CO emission reduction is 82.23%, and the level of HC emission reduction is 74,08%. The form of catalytic converter with plate variation 6 (six), the maximum CO2 emission reduction level is 29,56%, the level of CO emission reduction is 49.32%, and the level of HC emission reduction is 82,92%. (2) By using catalytic converters with plate variation 8 (eight) to produce power of 8.045 hp and torque of 8,833 n / m and for catalytic converters with plate variation 6 (six) producing power of 7.661 hp and torque of 8.493 n / m.

Performance test of Pikohidro Cross flow Water Turbine using multilevel double penstock

This study aims to examine the performance of pico hydro scale cross flow water turbines using multilevel double penstock as a conductor of water flow. Multilevel double penstock is used to reduce the transportation process from highways that are affordable to four-wheeled vehicles / cars to the location of the installation of the turbine. This condition causes the need for small-scale water turbine designs with lightweight construction with a kock down system. Overall the picohidro scale turbine construction is needed relatively cheaper transportation costs, so that people who have not been reached by the PLN network can be touched by small and cheap electricity. Turbine construction data has a runner diameter of 170 mm, body dimensions 200 mm x 300 mm x 250 mm, frame 250 mm x 800 mm. Pool tando 600 mm x 1200 mm and penstock length 16m. The power produced is theoretically around 2500 watts, with a data flow of 50 liters / second and a water level of 8 m. 65% efficiency. The research method is analyzing the double penstock water flow, by making paralon pipes in stages, ranging from 5 incci diameter, 4 inches and 3 inches, flow analysis approach using a gradient line, where the incoming water velocity and water velocity come out until entering the transmitting pipe. The performance results of this turbine provide an average actual power of up to 2000 watts. The stability of the inlet water condition is used by the Tando pond as a water bath. If there is excess water in the sediment tank, the water gate is used out, where excess water will automatically flow into the exhaust channel.

Performance assessment of long-legged tightly-baffled divertor geometries in the ARC reactor concept

Extremely intense power exhaust channels are projected for tokamak-based fusion power reactors; a means to handle them remains to be demonstrated. Advanced divertor configurations have been proposed as potential solutions. Recent modelling of tightly baffled, long-legged divertor geometries for the divertor test tokamak concept, ADX, has shown that these concepts may access passively stable, fully detached regimes over a broad range of parameters. The question remains as to how such divertors may perform in a reactor setting. To explore this, numerical simulations are performed with UEDGE for the long-legged divertor geometry proposed for the ARC pilot plant conceptual design—a device with projected heat flux power width () of 0.4 mm and power exhaust of 93 MW—first for a simplified Super-X divertor configuration (SXD) and then for the actual X-point target divertor (XPTD) being proposed. It is found that the SXD, combined with 0.5% fixed-fraction neon impurity concentration, can produce passively stable, detached divertor regimes for power exhausts in the range of 80–108 MW—fully accommodating ARC’s power exhaust. The XPTD configuration is found to reduce the strike-point temperature by a factor of ∼10 compared to the SXD for small separations (∼1.4) between main and divertor X-point magnetic flux surfaces. Even greater potential reductions are identified for reducing separations to ∼1 or less. The power handling response is found to be insensitive to the level of cross-field convective or diffusive transport assumed in the divertor leg. By raising the separatrix density by a factor of 1.5, stable fully detached divertor solutions are obtained that fully accommodate the ARC exhaust power without impurity seeding. To our knowledge, this is the first time an impurity-free divertor power handling scenario has been obtained in edge modelling for a tokamak fusion power reactor with of 0.4 mm.

РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ КОМПРЕССОРНОЙ И ТУРБИННОЙ ЧАСТЕЙ ТУРБОКОМПРЕССОРОВ С ОБЩИМ РАБОЧИМ КОЛЕСОМ ДЛЯ ПРИМЕНЕНИЯ В МАЛОРАЗМЕРНЫХ ДВИГАТЕЛЯХ

It is considered the issues of improving small-sized engines through the application of a new type of turbomachines – turbo-compressors with general impeller (TCG) to develop engines and power plants. For example, it is shown a diagram of the simplest small-sized gas turbine engine using TCG. For the systematization of relatively efficient TCG schemes, a classification has been developed and is given in the article, of possible schemes for a turbocharger with a common impeller. The classification is based on 5 possible directions of movement of the working medium in the blade apparatus – axial (parallel to the axis of rotation of the machine), centrifugal, centripetal, diagonal and tangential. To implement one or another flowing pattern in the impeller, it is necessary to select the appropriate shape of the impeller blades and the location of the nozzle, exhaust, suction and discharge channels relative to each other. Depending on the direction of movement of the gas flows, turbo-compressors with a common impeller may have two flow patterns in interscapular impeller space – direct-flow and counter-flow. If the directions of the gas and airflow coincide concerning the axis of rotation of the impeller, then the flow pattern in the TCG is direct-flow, with opposite flow flows it is countercurrent. For carrying out the enlarged gas-dynamic calculation of TCG, formulas are given that make it possible to calculate the circumferential force arising on the blades of the impeller in the compressor and turbine working channels of the TCG. Also, formulas are given, with correction factors, for calculating the power factor of the compressor part and the load factor of the turbine part. In the process of computational and experimental studies, the characteristic of the compressor part of the TCG experimental model was obtained. The test results of the compressor part of the TCG experimental model showed good agreement between the calculated and experimental values. Studies have shown that a turbocharger with a common impeller can be used as part of small-size gas turbine engines and in a turbo-supercharging system of a small-capacity internal combustion engine with not high supercharging.

Experimental study on the effects of exhaust heat recovery system (EHRS) on vehicle fuel economy and emissions under cold start new European driving cycle (NEDC)

Over the decades, unremitting efforts have been made to achieve energy conservation and emission reduction throughout the world. While for a vehicle engine, a great deal of the fuel energy is wasted as exhaust heat. Based on a novel exhaust heat recovery system devised and modified on a vehicle exhaust channel, the chief objective of this study is to improve the vehicle economy and emissions under cold start. Therefore, a detailed experimental investigation was conducted on the chassis dynamometer (CD) under cold start NEDC at 25 °C and −7 °C temperatures. And the method of comparative analyses of the coolant temperature, gasoline fuel consumption and exhaust emissions including total hydrocarbon (THC), carbon monoxide (CO) and nitrogen oxide (NOX) have been obtained to reveal the effects of EHRS on vehicle economy and emissions under cold start. The results show that, since the coolant temperature can be quickly increased with EHRS to shorten engine warm-up time under cold start, vehicle economy is enhanced during NEDC. Moreover, the device of EHRS can effectively alleviate the combustion deterioration and wall frame quenching effect in the cylinders under cold start, which greatly decreases THC emission. Although the excess air coefficient cannot be changed by EHRS, it can improve the combustion environment in cylinders, which contributes to the reduction of CO emission. It is unexpected to find that NOX emission is also decreased with EHRS actuation, which can be explained by a new theory called Fenimore mechanism. All these aims to provide helpful preliminary work for vehicles to meet the upcoming stringent limit of the real driving emission (RDE) of CHINA 6.

Enhancement and explosion-proof mechanism of aluminum fiber addition in Al2O3–SiC–C castables for iron runner

As a certain amount of water is typically discharged during the baking of castables, explosion of castables remains an issue. The explosion-proof performance and mechanical strength of castables are attracting increasing attention. In this study, the formation model of dense alumina-metal aluminum composite layer was established and an explosion-proof mechanism of aluminum fiber addition was proposed in this paper. The effect of aluminum fiber addition (0.5, 1, 2, and 3 wt%) on mechanical strength and burst resistance of Al2O3–SiC–C (ASC)-based castables for iron runner was studied. The results showed that the addition of metal aluminum fiber could effectively improve burst resistance, volume stability and mechanical strength of ASC castables. The castables had better strength when 0.10–0.20 wt% aluminum fiber was added. Closed pores with dense alumina layers and tiny exhaust channels relieved the stress, improving the mechanical strength of the castables. When the aluminum fiber content exceeded 0.20 wt%, the strength of the castables decreased because of the formation of interconnected pores. When 0.20 wt% aluminum fiber was added, the sample showed the best overall performance by forming pores with a dense layer of alumina.

Synthetic edge and scrape-off layer diagnostics—a bridge between experiments and theory

The scrape off layer (SOL) plasma in a Tokamak device and its coupling with the edge dictate the performance of a discharge to a high degree—especially as all plasma has to go through the SOL, which is the main exhaust channel for the hot plasma. This contribution provides an introduction to the modelling efforts of the plasma dynamics in the SOL and the edge regions. We employ a fully dynamical fluid model, the HESEL code. HESEL is equipped with synthetic diagnostic tools as probe arrays, Li-beam spectroscopy, and Gas Puff Imaging. Using the synthetic probe arrays to measure the electron and ion heat advection and conduction we obtain the upstream power fall-off length for a broad range of plasma parameters and by applying non-linear fitting procedures we derive the scaling of the fall-off length. The obtained results are in agreement with recent experimental observations from L-mode ASDEX Upgrade data. A workflow for generating synthetic Lithium beam data, where the fluctuation data from HESEL are passed to the RENATE code are discussed using experimental results from ASDEX Upgrade.

Optimization of Angle Adjustment Between Two Cutters’ Blades of Dry Areca Nut Peeling and Controlling Machine

The peeling-machine of dry areca nut is currently not working optimally. The nuts remained unpeeled properly since the machine is not equipped with an automatic power breaker as the peeler process has been completed or the machine life time is continuously. Undoubtedly, this is less efficient and wasteful of energy. From this point of views, it is necessary to conduct advanced research on appropriate technology to modify the peeling-machine so that it can peel dry areca nuts to the maximum for all available sizes. The research method includes the assembly of areca peeling-machine with a modification of the angle between the two cutters’ blades, the dimensions of the main cutter shape 191 mm in diameter cylinders that can be arranged into 12 cutters function as a peeler and a second cutter 163 mm in diameter with 20 cutters function towards the skin through the exhaust channel, rotation in the equal direction of 800 rpm. The peeler process is set to the angle between the two cutters’ blades and directed to the further process so that the dried areca nut that has been cut can be separated between the seeds and the skin. That is the expected result of the peeling-machine that can peel the dry areca nuts for all sizes optimally.

Joint Multi-Beam Training and Codebook Design for Indoor High-Throughput Transmissions Under Limited Training Steps

Along with the evolution of wireless technologies, users are expected to have high-throughput and low-latency indoor mobile applications, such as augmented reality and virtual reality. Therefore, the use of millimeter-wave for low-latency communications becomes attractive. Under low-latency criteria, a fast multi-link establishment is desired. In this paper, we present a novel concurrent multi-beam training jointly with a proposed multi-beam codebook. First, we propose a progressive multi-beam estimation (PMBE). This algorithm makes multiple coarse beams emerge within a few training steps. Second, we propose a Fast Fourier Transform (FFT)-based codebook which can be considered as a Discrete Fourier Transform based codebook built in a bit-reversal scrambler, thus forming a scattering multi-beam codebook. This FFT-based codebook design is optimally implemented on a sub-connected architecture, a hardware-efficient architecture. For fast multi-link establishment, we design our concurrent multi-beam training by combining the proposed PMBE jointly with the proposed FFT-based codebook, so as to further improve multiplexing gain. Since multiplexing gain can occur immediately, even under strictly-limited training steps, the high data rate can be achieved. Simulation results show that when reaching more than 95% capacity gain of exhaustive channel estimation, our work only spends 1% training steps of the exhaustive case.

Study of the Deposition Formation Mechanism in the Heat Exchanger System of RHF

In rotary hearth furnace (RHF) production, the heat transfer system will produce deposition, which blocks the exhaust channel. The formation of deposition will affect RHF production. In this study, the formation mechanism of deposition was determined through chemical composition analysis, XRD and SEM-EDS: the main cohered phase in the deposition was KCl and the secondary cohered phase was ZnFe2O4; the ZnFe2O4 had become solid since it was formed with a porous structure and it cohered other substances; the ZnFe2O4 exhibited stronger cohering strength than KCl, due to a different cohering mechanism. In contrast, the KCl played a significant role in the deposition on the heat exchanger wall. A new process was proposed to avoid the deposition formation. This process could eliminate the deposition in the heat transfer system of RHF and improve the utilization of metallurgical waste.

Numerical Investigation of Flow Near a Round Exhaust Channel Screened by an Annular Swirled Jet

Based on the Reynolds equations closed with the aid of the model of shear stresses transfer and of the model with a correction for curvature and rotation, numerical simulation of air flow near a round exhaust hole screened by an annular swirled jet was carried out. The influence of the swirling intensity on the air flow velocity field in the range of action of an exhaust device and its range of action at different flow rate ratios of the sucked and inflowing air and also at different distances of the circular hole from the axis has been determined. The results obtained will be of use in designing effective systems of exhaust ventilation of lowered energy capacity.

An X-ray chimney extending hundreds of parsecs above and below the Galactic Centre.

Evidence has mounted in recent decades that outflows of matter and energy from the central few parsecs of our Galaxy have shaped the observed structure of the Milky Way on a variety of larger scales1. On scales of 15 parsecs, the Galactic Centre has bipolar lobes that can be seen in both the X-ray and radio parts of the spectrum2,3, indicating broadly collimated outflows from the centre, directed perpendicular to the Galactic plane. On larger scales, approaching the size of the Galaxy itself, γ-ray observations have revealed the so-called 'Fermi bubble' features4, implying that our Galactic Centre has had a period of active energy release leading to the production of relativistic particles that now populate huge cavities on both sides of the Galactic plane. The X-ray maps from the ROSAT all-sky survey show that the edges of these cavities close to the Galactic plane are bright in X-rays4-6. At intermediate scales (about 150 parsecs), radio astronomers have observed the Galactic Centre lobe, an apparent bubble of emission seen only at positive Galactic latitudes7,8, but again indicative of energy injection from near the Galactic Centre. Here we report prominent X-ray structures on these intermediate scales (hundreds of parsecs) above and below the plane, which appear to connect the Galactic Centre region to the Fermi bubbles. We propose that these structures, which we term the Galactic Centre 'chimneys', constitute exhaust channels through which energy and mass, injected by a quasi-continuous train of episodic events at the Galactic Centre, are transported from the central few parsecs to the base of the Fermi bubbles4.

Performance investigation of an intermediate fluid thermoelectric generator for automobile exhaust waste heat recovery

In order to improve the power generation performance of automobile exhaust thermoelectric generator, an intermediate fluid thermoelectric generator system is proposed in this work. In the proposed system, the waste exhaust heat is transferred through boiling and condensation of the intermediate fluid. Consequently, the separation between the exhaust channel and thermoelectric module induces a higher heat flux on the hot side of the module. A mathematical model is also established to analyze the power generation characteristics of the proposed system. Compared with the traditional thermoelectric generator system, for the same heat exchange area on the exhaust side, not only is the peak output power increased by 32.6%, but the optimal thermoelectric module area is also reduced by 73.8%. The generation capacity per unit area is 1162 W/m2 at peak output power, which is 5.12 times that of the traditional thermoelectric generator system.

Improving the Gas-Exhaust System at Foundry Electrofurnaces

Abstract—Inspection of the gas-exhaust system at arc furnaces of capacity 3–10 t in the casting shops of manufacturing enterprises reveals problems responsible for copious gas and dust emissions in the production buildings, with degradation of the air quality. This is mainly associated with structural shortcomings of the systems for gas and dust evacuation from the furnace chamber through the exhaust channel, working window, and gaps between the housing and roof and also between the edges of the holes in the upper section and the electrodes within the holes. In particular, the moving joints between the rotary hoods and the gas-exhaust lines in such systems do not ensure reliable sealing. Accordingly, an improved design of the hood-rotation mechanisms has been proposed, with two sand barriers preventing the atmospheric emission of harmful emissions between the moving components. In the design of an industrial prototype, a method is developed for calculating the energy parameters of the drive in the improved system. A 1 : 10 scale model of the system is built to check the design and the theoretical equations. By means of a measuring system consisting of a tensoresistive converter, an ac amplifier, an analog–digital converter, and a computer, the load on the model’s drive on switching from the working position to the rest position and back is determined, for two cases: with and without sand barriers to seal the mobile components. The drag in the two sand barriers on rotation of the moving element amounts to 20–26% of the total load on the drive, depending on the angular velocity of the cantilever with the hood. According to the theoretical formulas, this figure is 17–23% for hood-rotation mechanisms in arc furnaces of capacity 3–10 t. Video recordings of the smoke fluxes from the model through the gaps between its housing and the roof during simulations of steel production confirm the reliability of the sand barriers, which ensure complete sealing of joints in the hood-rotation mechanism. Practical use of the proposed design improves gas–dust evacuation from the working zone of smelting furnaces used in the foundry.

Эффективность очистки и гидравлическое сопротивление струйно-фильтрационного пылеуловителя

The current study is aimed at the development of a methodology for calculating hydraulic resistance and the efficiency of cleaning dusty gases with a jet filter dust collector based on experimental data. This dust collector is applied in cleaning dusty gas streams of high concentration by means of a two-stage procedure. At the first stage, in order to minimise dust load, dust particles are deposited under the action of inertial forces arising from the sharp deceleration of a stream. At the second stage, a highly effective purification of the flow is ensured at the level of 98–99 % or more due to the filtering process through the bulk granular layer. Experimental studies of hydraulic resistance and cleaning efficiency of the jet and filter parts of the dust collector affected by jet velocity, nozzle design and its distance to the hopper, dust particle size and density, dust content of the gas flow, as well as dust properties, were carried out. The most significant influence on the increase in hydraulic resistance and the cleaning efficiency of the jet part was established to be exerted by the high-pressure head of the jet, the convergence angle of the nozzle and the shape of the air channel. The optimal limits of the jet velocity, the dimensions of the structural elements of the dust collector are determined, ensuring the efficiency of cleaning the dust and gas stream in the jet part by at least 80 %. Methods were developed for calculating the hydraulic resistance of the jet part of the dust collector based on the coefficients of local resistance, reducer, exhaust and air channel, depending on the density of the gas being cleaned and the average flow rate in the air channel. The hydraulic resistance of the granular filtering partition when clean, as well as during the accumulation of dust sediment, was determined. Based on the law of particle accumulation by a uniform filter as applied to granular layers, a method was developed for calculating the surface and thickness of the filter layer and the duration of the inter-regeneration cycle of the filter. The authors declare no conflict of interests regarding the publication of this article.

Numeric Simulation of the Effect of Varying Velocities on Catalytic Converter and Exhaust Gas Emission

Fossil fuel-powered vehicles are the most significant contributor to air pollution nowadays. They emit substances that are harmful to both human and environment. Carbon monoxide (CO) and Hydrocarbon (HC) is the most common harmful exhaust gases found in the environment. One of the technologies used for reducing CO emissions is catalytic converters. The catalytic converters usually installed in the exhaust system. The numeric study was conducted on the interaction of flow, reaction, and thermal effects in the form of a 2D model of the catalytic converter. Simulation using Fluent software was then used to find out the extent of the catalyst effects on CO gas absorption when velocities were 6.3 m/s, 15 m/s, and 20 m/s. The simulation revealed that CO mass fraction and temperature around the exhaust channel increased as the velocity increased.

Signal filtering method of the fast-varying diesel exhaust gas temperature

The paper presents the problem of the impact of external distortions originating on laboratory test stands on the results of measurements of fast-varying diesel exhaust gas temperature. It has been stressed how significant the aspect of the test stand adaptation is during an experiment to ensure the smallest possible impact. This paper, however, focuses on the methods of mathematical processing of a signal recorded during experimental research of a real object. The most significant parameter requiring filtering is the fast-varying exhaust gas temperature in the engine exhaust channel. Methods of mathematical processing adequate to this type of distorted signal have been presented, particularly those that can be used in the Matlab environment and consisting in averaging of the obtained curves of temperature changes. The results of the application of these methods have also been presented on actual curves recorded during laboratory tests and their evaluation has been made.

Development and performance analysis of a TEG system using exhaust recovery for a light diesel vehicle with assessment of fuel economy and emissions

Exhaust heat from vehicle engines can be one of the promising heat sources to provide additional energy using thermoelectric generation (TEG). However, the objective of this study is to assess the exhaust heat recovery behavior by TEG, evaluation of diesel fuel consumption (DFC) and exhaust emissions. Thirty standard thermoelectric modules (TEMs) were mounted on the two sides (1 × 5) and lower side (4 × 5) arrangement of a light diesel vehicle exhaust channel. A detailed experimental work was carried out to study the performance behavior of TEG system with different engine speeds and over new European driving cycle (NEDC) using chassis dynamometer. Comparative analyses of the exhaust gases flow rate, DFC, exhaust emissions such as THC, CO, CO2, and smoke emissions have been measured during NEDC with and without TEG actuation. Experimental results observed that the average value of TEG system efficiency is approximately 4.63% under the NEDC conditions. It also found that: by actuation the TEG system, the effectiveness of DFC percentage has been reduced by (1.46%–3.13%), lower exhaust gas emissions were found, too. The experimental result of output power is in good agreement with the theoretical result within 5.16% error at 1500 rpm.

Model of Processes of the Al25/30 Marine Engine and its Verification

Abstract The work presents a model of the marine diesel engine working process. The research object was the AL25/30 engine. The model consists of partial models of the combustion process in the engine cylinders, the heat exchange process, flows through air and exhaust channels, heat exchange in the intercooler and friction in mechanical components of the engine. The model includes a description of the processes taking place in the turbocharger also. The input data to the model and the verification data were the results of direct measurements on the research facility. The verification showed errors in the calculation of air and exhaust gas parameters not exceeding 11%. The paper also presents an analysis of the results of fast-changing parameters, including combustion pressure in engine cylinders and pressures in individual gas channels. The designed model allows the analysis of the research facility operation and enables its further development towards the assessment of toxic compounds emission to the atmosphere.

Calculation air regime of a residential building with individual exhaust channels

Purpose. This article deals with the algorithm of the air renewal calculation of the building on the example of a residential building in order to determine correspondence of the incoming and removed air quantity to the characteristics of the current standards. The algorithm of calculation allows to determine the air consumption and direction of flow that are filtrated through the hole in the enclosing structures and removed by local vent systems natural ventilation. Method. This calculation can be performed on the electronic computing machine (computer) using one of the programming languages. Result. The calculation program will consist of two units: the unit of pre-calculations, and unit of iterations. The unit of preliminary calculations deals with the boundary conditions and the calculation of the resistance characteristics of air-penetrating building elements (windows, doors) and the characteristics of aerodynamic resistance of sections of the ventilation system. The iterative unit deals with the determination of internal pressure in rooms and air consumption, filtered through the air-penetrating holes and removed by local vent systems. The solution of the air renewal of a building is the description of its balance equations for each apartment, an elevator hall and a corridor. In this example we see a separate local vent from each ventilating grid that does not provide for a recalculation of characteristics of aerodynamic resistance of sections of ventilation systems depending on the change of the air consumption in them. Conclusion. The results of the calculation of the air renewal may show whether the air consumption (the incoming and removed air quantity) corresponds to the characteristics of the current standards. The resulting pattern of air renewal of the building will allow to determine whether there are some deficiencies in the ventilation system.