Browse Topic: Air cleaners
One of the advantages of the internal combustion engine is that it can function with relatively simple intake air filtration. Provided that dust is kept out, air entering the engine can ensure that the necessary combustion process takes place. So, a relatively simple dust filter will do the job. By comparison, hydrogen fuel cells are far more sensitive to air quality. Other pollutants can affect both fuel-cell performance and the lifetime of the fuel-cell stack. At the recent IAA Transportation Show in Hanover, Germany, Donaldson Filtration Solutions displayed tailored solutions through its range of cathode air filters. These typically rely on multiple layers - including activated carbon, an acid and base layer, and a dust filter - to screen out sulphur dioxide, nitrogen oxides and ammonia, while allowing for customization to protect against butane, toluene and other unwanted compounds.
Vehicle interior air quality is usually determined by the levels of in-cabin air pollutants, such as particulate matter (PM), gaseous air pollution (volatile organic compounds [VOCs], oxides of nitrogen [NOx], and carbon monoxide [CO]), and carbon dioxide [CO2], which reflect the freshness of indoor air. Nowadays, cabin air filters play a key role in preventing outdoor air pollutants transporting inside vehicles; hence, in-cabin air quality can be strongly associated with the filtration performance of cabin air cleaning solutions. However, challenges are existing in a standard method for assessing the performance of a cabin air filter in real-life driving conditions. This study is to develop a low-cost mobile test method for monitoring in-vehicle PM and CO2 and evaluating the performances of cabin air filters while driving the vehicles. The results reveal that certain boundary conditions are important to have a proper method for evaluating the particle removal efficiency. For example, recirculation ventilation can lead to high PM2.5 removal efficiency regardless of the status and performance of a cabin air filter, and the remarkable increase in CO2 in a short time is an obvious indicator of the activation of recirculation. Fresh air ventilation is effective in maintaining the in-cabin freshness without the built-up of interior CO2; however, drivers can be exposed to a high level of PM2.5 concentrations with cabin air filters of poor performance. For the vehicles involved in this study, the average PM2.5 removal efficiencies were about 17-50% under fresh air with existing installed cabin air filters (more than 3 months since installed). With a brand-new filter (original cabin air filter and CabinAir Nordzone™ filter), the vehicle could filter out about 80-86% of outdoor PM2.5. The application of ionization technology together with the Nordzone™ filter was proven to further enhance the PM2.5 removal efficiency by up to 97%. Future work would be of great interest to investigate the aging performance of those optimized cabin air filters and the contribution of ionization, as a promising technology to improve the performance of cabin air filters, on those aged filters in real-driving environments.
HVAC systems of passenger cars and especially their air purification performance gained prominence during the last years. One reason is the overall increased attention to air quality and its effect on human health. Recently, the WHO further tightened the recommended values for many pollutants. This will likely intensify the trend to more complex systems for improving the air purification functionalities. But, up to now there is no standard method for air purification performance testing. Existing standards cover the vehicle cabin air quality only regarding material emissions. Several studies address assessing the performance of air purification functionalities in most cases by real driving tests typically performed in urban areas. This approach results in proper values for the basic efficiency of single systems. But the level of pollutants in real environments differ considerably, which makes a comparison of different systems or varying application parameters at least complex. Hence, the aim of this study was to provide a controllable lab test environment for testing the whole vehicle with its HVAC system regarding its air purification performance. An atmosphere of KCl particles (focus on PM2.5) was chosen for representing the pollutant class of particulate matter. In addition, CO2 was identified as an important pollutant, whose source is not the surrounding environment but the vehicle passengers. Literature reveals that the CO2 concentrations within the vehicle cabin can reach critical concentrations, especially for air-recirculation mode and for a higher number of passengers. Hence, a system for dosing CO2 was set up. It has five channels to simulate the CO2 exhalation of up to five passengers. Its usability was tested by comparing the resulting CO2 concentrations to an experiment with real passengers. At the end a feasible lab test environment was created. Furthermore, introduction of other pollutants (e.g., CO, O3, NOx, biological matter) is also possible.
This document describes methodologies to determine the causes blow-by oil consumption caused by the power cylinder.
This document describes methodologies to determine the causes of high oil consumption caused primarily by the power cylinder system.
The purpose of the article is to evaluate the cooling performance efficiency of a Compressed Natural Gas (CNG) medium commercial vehicle with a viscous fan, fresh air cleaner, and choked air cleaner in comparison with limits prescribed in the Indian Standard (IS) 14557. Due to the increase in CNG availability, a shift is observed in the market demand for CNG vehicles. The earlier CNG vehicle duty cycle was limited to plain roads and some limited cities, but now vehicles are being used for a short trip to nearby hilly routes thereby shifting the application of the use of a CNG vehicle. CNG vehicles can now be operated in hilly areas where power and torque demand is maximum and operates at lower vehicle speeds and in lower gears. The subjected vehicles are designed for haulage applications to operate with conventional fixed fans, which are permanently engaged, and smaller radiators. The subjected vehicle was previously designed as per the requirements of the existing road application with a fixed fan and small radiator. Vehicle configuration was modified to the viscous fan and bigger radiator available as off-the-shelf components from the component suppliers. Viscous fans operate only when the coolant temperature goes beyond certain limits for better cooling performance of the engine, lower cabin noise, and higher fuel efficiencies. The main objective of this article is to compare the thermal behavior in different vehicle configurations by data acquisition and thereby establish the fact that subjected CNG vehicles can be used in difficult terrains due to broad CNG availability with maximum performance. The results obtained during the experiment with a smaller fixed fan and bigger viscous fan are at an ambient temperature above 35°C and, for a time, more than 5 minutes as specified in IS 14557. Base data is collected with the existing configuration of a vehicle with a small fixed fan and small radiator. Afterward vehicle configuration is changed to the viscous fan and bigger radiator and tested at conditions worse than as specified in the test standard, i.e., ambient temperature more than 35°C and, for a time, more than 5 minutes to ensure driveability in all terrains. Then the experiment is conducted at maximum power condition with fresh air cleaner and choked air cleaner. Another experiment is conducted to check the worst-case running in maximum torque condition with fresh air cleaner and choked air cleaner. After establishing the results in the first and second experiments, another two experiments were conducted to check the actual performance of the vehicle in plains and hilly route simulation as well.
In a photocatalytic air purifier system, the catalyst that cleans the air is typically titanium dioxide and it is energized by ultraviolet (UV) light. When UV light shines on the titanium dioxide, electrons (negatively charged particles inside atoms) are released at its surface. The electrons interact with water molecules (H2O) in the air, breaking them up into hydroxyl radicals (OH·), 9which are highly reactive, short-lived, uncharged forms of hydroxide ions (OH−). These small, agile hydroxyl radicals then attack bigger organic (carbon-based like virus) pollutant molecules, breaking apart their chemical bonds and turning them into harmless substances such as carbon dioxide and water. Current investigation uses the above principle to kill living organic germs, bacteria; pathogen, etc. from the cabin air in recirculation mode. A HVAC system has been developed by using a filter impregnated by titanium di-oxide (TiO2) with UV lights to improve and maintain cabin air quality. The developed system has been developed to kill virus, germs, pathogens and bacteria that typically exist in a conditioned space. The designed system can be used for conventional vehicles, EVs, ride sharing and for autonomous vehicles. Tests were conducted at a certified laboratory with MS2, a bacteriophage size of 0.027 microns. MS2 is a proxy for SARS-CoV-2, the virus that causes COVID-19 with a size of 0.125 microns. Effectiveness of the destruction rate was determined for the developed system. Detailed summary will be presented in the paper.
Currently automotive sector is facing bi-fold challenge of light weighting and cost reduction. As end-customer is getting more focused on total cost of ownership, it is need of time that light weighting and cost reduction goes hand in hand. Presently lightweight materials such as magnesium, aluminum & composites are used but often this impact towards cost increase. In present study, a novel approach has been followed which not only focus on light weighting but also integrate design functions of two engine systems. This paper deals with the new system design to focus on low cost, light weight, NVH friendly and low development time. In design phase, function of two engine systems i.e. engine cover and Air filter were integrated followed by structural analysis. In final phase of this project, the experimental component was developed and validated for its intended function. In this study, current sheet metal design engine cover has been converted in to Thermoplastic cover with integrated Air filter. The complete engine cover with integrated air filter design has been validated at Test bed and Vehicle level for durability, performance, leakages, NVH. At end results were analyzed and compared. Results indicates that new design is a better solution over the existing design. The study demonstrates that this novel approach of light weighting and design function integration can achieve better performance while providing substantial cost saving and weight reduction.
Currently automotive design is facing multi facet challenges such as reduction in greenhouse gases, better thermal management, and low cost solution to market, vehicle weight management etc. Considering these challenges, efforts had been taken to improve weight management of engine while optimizing the cost of it. Good ‘engine breathing’ is usually associated with efficient intake system e.g. high flow air filter, a well-designed manifold, cylinder block, cylinder head and cylinder head cover etc. However, efficient ‘crankcase breathing’ is an equally important function of any engine. Even in a new engine, the combustion pressure will inevitably pass the piston rings into the crankcase. If an engine’s breathing system should become blocked or restricted, the crankcase will pressurize causing lots of problems to the engine. Prior to 1963 most vehicle engines vented their vapors and oil deposits to atmosphere and the road surface. With increasing environmental pressures positive crankshaft ventilation was introduced whereby the crankcase vapors were drawn up into the inlet manifold and, along with the air/fuel mixture, burned up in the combustion chambers. To enable this system to work safely and efficiently the ventilation from the crankcase is controlled via a PCV valve which can be integrated with the engine cylinder head cover. A cylinder head cover, particularly for covering a cylinder head of an internal combustion engine, having a plurality of functional elements such as an oil filling connection and at least one oil separation device mounted thereon. There are different materials can be used for cylinder head cover, but we have selected plastic material for engine weight reduction. This design change was successfully introduced on light duty diesel engine with newly featured three leap cylinder head cover gasket to ensure positive sealing of engine gases and engine lubricant.
Fuel cell technology can play a major role in reducing transportation-related emissions, especially in heavy-duty, long-haul applications. Consequent transfer of technology from air supply systems for combustion engines to cathode air paths serves as an enabler for necessary system cost reduction. To achieve the required system lifetime, the supply of clean air is essential. Gases like NOx, SO2 and NH3 poison the catalyst, leading to increased stack degradation rates. Effective removal with functionalized activated carbons enhances the catalyst´s lifetime. Research on real-life concentrations of these contaminants under different driving patterns and road profiles enables knowledge-based design of cathode air filter elements. To prevent flooding of components like air filter, humidifier, or stack, water separators are integrated at different position inside the system. Plastic air ducts with integrated sensors and flaps required to manage the air flow connect the different functional components. Broadband silencers are applied to reduce noises inside the system, e.g. generated by the compressor. Essential components like humidifier and air-cooler can easily be incorporated into the system. In the cathode air exhaust path, an additional water separator is applied to protect turbine blades and to prevent emission of splash water from the tailpipe. The consistent transfer of technology from air supply systems for combustion engines to cathode air paths enables cost-, noise and packaging-optimized, plausible system concepts with enhanced energy efficiency.
This SAE Aerospace Information Report (AIR) covers airbone particulate contaminants that may be present in commercial aircraft cabin air during operation. Discussions cover sources of contaminants, methods of control and design recommendations. Air quality, ventilation requirements and standards are also discussed.
Paccar has announced a new 12-speed automated transmission (AT) and column-mounted shifter to improve fuel economy and driver ergonomics in Peterbilt and Kenworth models in North America beginning in October. The transmission and shifter were jointly developed to provide a superior shifting experience while reducing weight. “The Paccar Transmission offers best-in-class performance, reliability and low cost of operation,” said Kyle Quinn, Peterbilt general manager and Paccar senior vice president. “With the availability of this innovative transmission, the proven MX-13 engine and the efficient Paccar Axle, the Peterbilt Models 579 and 567 can now be spec'd with the industry's most advanced proprietary drivetrain.”
Passive, tuned acoustic absorbers, such as Helmholtz resonators (HR) and quarter-wave tubes, are commonly used solutions for abating the low-frequency tonal noise in air induction systems. Since absorption at multiple frequencies is required, multiple absorbers tuned to different frequencies are commonly used. Typically, the large size and multiple numbers of these devices under the hood is a packaging challenge. Also, the lack of acoustic damping narrows their effective bandwidth and creates undesirable side lobes. Active noise control could address all of the above-mentioned issues. Most active noise control systems use feedforward adaptive algorithms as their controllers. These complex algorithms need fast, powerful digital signal processors to run. To ensure the convergence of the adaptation algorithm, the rate of adaptation should be made slow. This might lower the effectiveness of the controller during the transients, e.g., a fast run up of the engine in an induction or exhaust noise control application. An alternative to the feedforward active noise cancellation is feedback-based active noise control. Feedback noise control strategies are more straightforward and computationally less demanding than adaptive feedforward schemes and thus can be programmed in less expensive micro-controllers rather than digital signal processors. Contrary to feedforward scheme where the microphone and speaker are located upstream of the air filter and thus subject to the environmental elements, in proposed feedback scheme, they are placed downstream of the engine air filter and are well protected. An active feedback noise control system is developed for an air induction system and its effectiveness demonstrated in a laboratory set up. A number of 2nd order filters programmed in a microcontroller were used to control the engine noise at multiples tones. The effectiveness of the actively controlled system matched or exceeded that of the traditional induction system with multiple passive acoustic absorbers.
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