Traditional cellulose filter media used for air filtration in vehicle engines are characterized by 99.9% filtration efficiency and accuracy above 2–5 µm. The highest engine component wear is caused by dust grains above 1 µm. Filter media with nanofiber additions provide greater filtration efficiency of dust grains below 5 µm. Filter material selection for vehicle engine air filter is a problem because their manufacturers mainly provide only the structure parameters: pore size, air permeability, and thickness. There is no information about material filtration properties using polydisperse test dust. The manuscript presents methodology and experimental test results of five samples A, B, C, D and E, filter materials differing in their chemical composition and structure parameters. In the first stage, efficiency characteristics φw, filtration accuracy dzmax and the flow resistance Δpw depending on the dust absorption coefficient km of three filter cartridges of each material, A, B, C, D and E, were determined. Then, from each material characteristics of one piece was selected in order to compare their initial and initial period efficiencies as well as changes in the flow resistance depending on the dust absorption coefficient km. Obtained results showed that the filter materials differ significantly in efficiency and accuracy values in the initial filtration period. Initial period duration is also different, i.e., filtration efficiency increasing time to a certain value, which for materials with a nanofiber layer is much shorter, which minimizes engine component wear. For materials with nanofibers, flow resistance increase intensity is greater, which results from surface filtration. Filtration efficiency of each filter material sample A, B, C, D and E was assessed with the filtration quality coefficient including the efficiency and flow resistance. In the available literature, the problem of increasing filtration efficiency in the initial period is known, but there are no results for specific filter materials. Research shows that filter material characteristics are closely related. Each increase in efficiency and accuracy of intake air filtration reduces engine components wear, but it is related to flow resistance increase in the engine intake system, which reduces its power, and increases need for more frequent filter servicing.

The paper presents the problem of the effect of air filter pressure drop on the operating parameters of a modern internal combustion engine with compression ignition. A literature analysis of the results of investigations of the effect of air filter pressure drop on the filling, power and fuel consumption of carburetor and diesel engines with classical injection system was carried out. It was shown that each increase in the air filter pressure drop Δpf by 1 kPa results in an average decrease in engine power by SI 1–1.5% and an increase in specific fuel consumption by about 0.7. For compression ignition engines, the values are 0.4–0.6% decrease in power and 0.3–0.5% increase in specific fuel consumption. The values of the permissible resistance of the air filter flow Δpfdop determined from the condition of 3% decrease in engine power are given, which are at the level of 2.5–4.0 kPa—passenger car engines, 4–7 kPa—truck engines and 9–12 kPa—special purpose vehicles. Possibilities of decreasing the pressure drop of the inlet system, which result in the increase of the engine filling and power, were analyzed. The program and conditions of dynamometer engine tests were worked out in respect to the influence of the air filter pressure drop on the operation parameters of the six-cylinder engine of the swept volume Vss = 15.8 dm3 and power rating of 226 kW. Three technical states of the air filter were modeled by increasing the pressure drop of the filter element. For each technical state of the air filter, measurements and calculations of engine operating parameters, including power, hourly and specific fuel consumption, boost pressure and temperature, were carried out in the speed range n = 1000–2100 rpm. It was shown that the increase in air filter pressure drop causes a decrease in power (9.31%), hourly fuel consumption (7.87%), exhaust temperature (5.1%) and boost pressure (3.11%). At the same time, there is an increase in specific fuel consumption (2.52%) and the smoke of exhaust gases, which does not exceed the permissible values resulting from the technical conditions for admission of vehicles to traffic.

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Article citation info: (*) Tekst artykułu w polskiej wersji językowej dostępny w elektronicznym wydaniu kwartalnika na stronie www.ein.org.pl DZIUBAK T, SZWEDKOWICZ S. Operating properties of non-woven fabric panel filters for internal combustion engine inlet air in single and two-stage filtration systems. Eksploatacja i Niezawodnosc - Maintenance and Reliability 2015; 17 (4): 519-527