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Positive Crankcase Ventilation System
Abstract
In this paper, we have studied the traditional Positive Crankcase Ventilation (PCV) valve equipment. Then we have improved the system by adding ventilation equipment. We have applied this kind of connection equipment on gas engine which has no PCV. This can determine the engine fuel-air ratio and make the engine get the best power performance, economical efficiency and emission behavior. Because emission amount is based on input air amount, so how to control the input air amount is the basis of the whole system. On the basis of traditional inlet manifold MVEM, we have considered the affection of PCV system, and we have simulated the actual input air process by getting improved module’s input air amount and inlet manifold pressure parameters. So the fuel-air ratio precision can be increased greatly. We also have prompted some improving directions about traditional inlet manifold. So we can ensure that engine can get a compact structure and good response on the all operation states.
... In addition, in case of incomplete combustion of IC Engine produce carbon monoxide (CO) and hydro carbon (HC) emissions. One of the efforts to reduce air pollution from IC Engine is known by applying the positive crankcase ventilations(PCV) systems.This system serves to protect the environment effect from emissions of crankcase consisting such asengine oil vapour, water vapour, and other gas that enter back into the intake manifold and burned in the combustion chamber[3].However, vapour oil has long chain carbon which will cause incomplete combustion, so it increases emissions in IC engine. ...
The main problem SI engine with a positive crankcase ventilation system (PCV) is the formation of carbon crust due to the evaporation of the lubricating oil. This condition will cause engine knocking as well as performance decreases.This problem can be reduced by adding oil catch tank between the PCV valve and the induction chamber. This research aims to select the type of filter OCT to generate the optimal engine performance.Engine performance is indicated by decreasing of hydrocarbons and carbon monoxide emissions. While decreasing engine knocking is indicated by the coolant temperature. Water, natural zeolite and the urethane foam were used as a filter to determine which type of filter OCT generate the optimum engine performance. The coolanttemperature and the exhaust emissions were measured at the engine speed of 750, 1500, 2500 and 3000 rpm.The results of this study show that zeolite filter has the most optimum performance in all engine speed conditions.
... Thus, the Positive Crankcase Ventilation (PCV) was developed and integrated to their cars by 1963 [3]. According to Ding [4] , the main function of the PCV is to extract the mixture of gas-droplets from the crankcase by drawing fresh clean air in. The mechanism of operation is simple: air passes through the oil drain back passages to the crankcase below, displacing the dirty air-oil mist and hydrocarbons to the PCV valve. ...
The Positive Crankcase Ventilation (PCV) system in a car engine is designed to lower the pressure in the crankcase, which otherwise could lead to oil leaks and seal damage. The rotation of crankshaft in the crankcase causes the churn up of oil which conducts to occurrence of oil droplets which in turn may end in the PCV exhaust air intended to be re-injected in the engine admission. The oil catch can (OCC) is a device designed to trap these oil droplets, allowing the air to escape from the crankcase with the lowest content of oil as possible and thus, reducing the generation and emission of extra pollutants during the combustion of the air-fuel mixture. The main purpose of this paper is to optimize the design of a typical OCC used in many commercial cars by varying the length of its inner tube and the relative position of the outlet from radial to tangential fitting to the can body. For this purpose, CFD parametric analysis is performed to compute a one-way coupled Lagrangian-Eulerian two-phase flow simulation of the engine oil droplets driven by the air flow stream running through the device. The study was performed using the finite volume method with second-order spatial discretization scheme on governing equations in the Solid Works-EFD CFD platform. The turbulence was modelled using the k-ɛ model with wall functions. Numerical results have proved that maximum efficiency is obtained for the longest inner tube and the tangential position of the outlet; however, it is recommended further investigation to assess the potential erosion on the bottom of the can under such a design configuration.
div class="section abstract"> Manufacturers of internal combustion engines are changing their focus to non-conventional fuels like hydrogen in response to the worrying global warming situation. When compared to conventional fuels like gasoline or diesel, the use of gaseous hydrogen fuel in an internal combustion engine powered by hydrogen can lessen the engine's negative environmental effects. But occasionally, hydrogen can leak from the high-pressure fuel injection system to the engine top cover and as blowby within the crankcase. Static zones may emerge because of these H2 leaks. Potential explosion or fire can result when the H2 concentration in these stagnation zones is more than 4% and triggers a minimum ignition energy of 0.02 mJ.
A CFD simulation methodology incorporating multi-species model, piston, and crank motion to estimate the H2 concentration within crankcase is developed. The simulation development phases has been presented in the paper. The blowby values are determined from the experimental measurement and used as the inputs. The dilution strategy by varying the number of vent ports, location, size for crankcase is examined using this simulation. The flow requirements at various speed also deduced. Further, for under hood and engine top cover, underhood analysis is carried out to ascertain the accumulation within the engine and its compartment. Fan ON and OFF scenario is studied, and results are discussed.
H2ICE blowby and H2 % concentration at breather tube out is correlated with test for a baseline case. A good correlation matching the experimental trend is observed in the simulation.
The study helped engine program to complete the optimization and design verification through simulation and get the best concept implemented.
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In response to the outbreak of the novel corona virus pneumonia (COVID-19 pneumonia) in late 2019, many temporary emergency hospitals have been built or rebuilt in some key areas in China. The environment of hospital negative pressure isolation room is closely related to medical workers’ health and safety, while ventilation system has been the major means of environmental control. The design points of Wuhan Leishenshan Hospital (also named as the Thunder Mountain Hospital, which was specifically built to address the COVID-19 pneumonia in February 2020) was briefly introduced and analyzed in the article, as well as some essential elements of the ventilation design to build negative pressure isolation rooms, such as ventilation volume design standard, differential pressure control standard and airflow direction strategy. The measures of differential pressure control are also illustrated in the article. The points in the assay could be used as reference for those engaged in the future designing and construction of infectious disease hospitals.KeywordsCOVID-19 pneumonianegative pressure isolation roompressure differenceair distribution
A dynamic model of a free piston generator (FPG) was developed considering the operation principle of FPG based on dynamics and thermodynamics equations. Then the dynamics characteristic of FPG has been achieved through the numerical solution of the dynamic model. Furthermore the influence of the input parameter of FPG system characteristics and the frequency characteristic were discussed. The results showed that FPG is a self-exciting system and stable performance could be achieved by appropriate control.
Fuel consumption is studied on a diesel engine fueled with emulsified diesel fuel and with ethanol preheated by exhaust gas and injected into air intake. This technique can achieve good oil economy and reduce BSFC (brake specific fuel consumption) by as much as 10%. The consumption of diesel fuel alone can be reduced by about 16%. Hydrogen produced in ethanol pyrolysis and the use of emulsified fuel together contribute to the fuel economy. The technique adopted in the present work is easy to utilize, and its application on diesel engines for power plants, trains, and ships, is suggested.
Matlab/Simulink, Chemkin as well as the finite element method (FEM) have been used to investigate the performance of the novel development of HCCI free piston linear alternator (FPLA). The motion differences between the FPLA and the internal combustion engine (ICE) were also presented. The effects of various resistance loads and equivalence ratios were studied. The simulation results showed that the FPLA has a build-up nature to change the top dead center (TDC) according to loads and other parameters. The high compression ratio could be achieved easily, which is an effective way to reduce the emissions and increase the thermal efficiency.
Study on Gasoline Intake Model Modification Based on PCV
- L I Li Ding-Gen
- Xiao-Zhong
LI Ding-gen, LI Xiao-zhong, Study on Gasoline Intake Model Modification Based on PCV[J], VEHICLE
ENGINE, 2009(1)
Application of PLC in marine diesel engine rate governor
- Huang Fang
Huang Fang, Application of PLC in marine diesel engine rate governor[J], JIANGSU SHIP, 2007 24(3)