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Technical Paper

Characterization of Deposits and Effects of Detergent Additive, Olefin Content and Engine Oil on Intake Valve Deposit Formation

This study focused on the characterization, in term of quality, of intake valve and combustion chamber deposits collected by Toyota 1G-FE IVD test, which was developed for in-house IVD test in the Petroleum Authority of Thailand. Various analytical techniques were utilized to characterize deposits according to elemental analysis, thermal gravimetry analysis (TGA) and infrared spectroscopy in combination with solvent extraction. The results indicate that IVD contains more hydrocarbon oil and heavy fraction of gasoline than CCD, while the contents of organic oxidized products, carbonized compounds and inorganic additives in IVD are less. Resulting from hexane soluble extraction, the gasoline detergent additives in IVD are confirmed. The TGA result shows that PEA additive can be decomposed at lower temperature than PIBA additives. Comparing between piston top and cylinder head CCD, it was determined that “Oil up” phenomenon occurred at piston top more than cylinder head.
Technical Paper

Direct Injection Spark Ignition Engine Deposit Analysis: Combustion Chamber and Intake Valve Deposits

The delicate balance between global supply and demand for energy, in conjunction with environmental concerns related to burning fossil fuels, have resulted in vehicle designs that stress higher fuel economy. Among new engine designs is Direct Injection Spark Ignition, or DISI, which employs a more precise fuel metering system and is designed for combustion at higher compression ratios than Port Fuel Injection (PFI) engines. As a result, the performance of DISI engines can easily be altered by the presence of carbonaceous deposits on intake valves and in the combustion chamber. In this study, the characteristics of these deposits have been investigated using elemental and thermal analytical techniques. Deposits from intake valves and combustion chambers have been collected from various DISI engines (both older and more modern ones).
Journal Article

Formation of Intake Valve Deposits in Gasoline Direct Injection Engines

Gasoline direct-injection (GDI) engines have a well-known propensity to form intake valve deposits (IVD), regardless of operator service, engine architecture, or cylinder configuration. Due to the lack of a fuel-washing process that is typical of Port Fuel Injected (PFI) engines, the deposits steadily accumulate over time and can lead to deterioration in combustion, unstable operation, valve-sticking, or engine failure. Vehicles using these engines are often forced to undergo expensive maintenance to mechanically remove the deposits, which eventually re-form. The deposit formation process has not been well-characterized and there is no standardized engine test to study the impact of fuel or lubricant formulation variables. To meet this need, a proprietary vehicle-based GDI-IVD test that is both repeatable and responsive to chemistry has been developed.
Technical Paper

Noise Metrics and Subjective Assessment of Automotive HVAC Systems

HVAC systems are of critical importance in ensuring passengers’ thermal comfort inside the car cabin as well as safety requirements for defogging functions. These systems involve various components and subcomponents such as blowers, thermal exchangers or actuators, with a wide range of well-known technologies and also new ones on recently introduced innovative products. Currently, within established electrification trends worldwide, the HVAC system is becoming the most important embedded system that can induce major contribution of noise and vibration. These NVH issues can emerge through different transfer paths inside the car cabin possibly causing significant discomfort to passengers. During developments, the NVH issues are mastered and contained by both suppliers according to internal requirements and OEMs according to specifications.
Technical Paper

A Preliminary Study on the Evaporative Cooling System for FCEV

The existing FCEV have been developed with only a few vehicle models. With the diversification of both passenger and commercial FCEV lineups, as well as the increasing demand for vehicle trailer towing, there is a growing need for high-capacity fuel cell stacks to be applied in vehicles. However, at the current level, there are limitations and issues that arise, such as insufficient power output and reduced driving speed. As a results, the importance of thermal energy management has been increasing along with the increase in required power. Traditional cooling performance enhancement methods have mainly focused on developing increased hardware specifications, but even this approach has reached its limitation due to package, cost and weight problem. Therefore, it is essential to develop a new cooling system to solve the increases in heat dissipation.
Technical Paper

Design and Optimization of a Centrifugal Compressor-Based Air Management System for HD Fuel Cell Applications

Fuel cell electric vehicles offer an attractive option for decarbonizing long-haul on-road transport. However, there are still several barriers to widespread adoption of hydrogen-fueled fuel cells for this application including system durability and total cost of ownership compared to traditional diesel engines. A primary contributor to fuel cell system costs and maintenance requirements is the air management system. It is common for heavy duty fuel cell electric vehicles to use light-duty automotive air management components which are ill-suited for the requirements of larger, long-haul vehicles. This study focuses on the development of a durable and efficient air management system for heavy duty vehicle applications as part of a cooperative research project funded by the Department of Energy’s Hydrogen and Fuel Cell Technologies Office1.
Technical Paper

A New Gen ‘Super-Efficient Condenser’ for Mobile Air Conditioning Application

In the modern era of automotive industry, occupant comfort inside the cabin is a basic need and no more a luxury feature. With increase in number of vehicles, the expectations from customers are also changing. One of the major expectations from real world customers is quick cabin cooling thru all seasons, particularly when the vehicle is hot soaked and being used in summer conditions. Occupant thermal comfort inside the vehicle cabin is provisioned by a mobile air conditioning (MAC) system, which operates on a vapor compression-based cycle using a refrigerant. The main components of a direct expansion (DX) based MAC system are, a compressor, condenser, evaporator, and expansion valve. Conditioned air is circulated inside the cabin using a blower, duct system and air vents. The AC condenser is the most critical component in AC circuit as it rejects heat, thereby providing for a cooling effect inside the cabin.
Technical Paper

A Study on Optimization Development of Cooling Fan Motor for EMC

With the trend of electrification and connectivity, more electrified parts and more integrated chips are being applied. Consequently, potential problems based on electro-magnetic could occur more easily, and interest on EMC performance has been rising according to the degree of electrification. In this paper, one of the most severe systems, cooling fan motor in terms of EMI, is analyzed and improvement methods are suggested for each type of cooling fan. Additionally, an optimized configuration of improvement method for EMC has been derived through analysis and study. Finally, verification and validation are implemented at the system and vehicle levels.
Technical Paper

The Effects of Engine Oils on Intake Valve Deposits and Combustion Chamber Deposits

Short deposit sampling procedures were employed in a single-cylinder CFR engine to investigate the potential which an engine oil or an oil component has for forming deposits. Both valve temperature and oil flowrate on a valve have significant effects on an oil's deposit forming tendency. However, the formulation of the oil is the dominating factor that determines whether an oil will keep a valve clean or form heavy deposits. Among the oil components, oil detergents, dispersants, and VI improvers are major contributors to intake valve deposits, while high-boiling base oil can keep a valve clean. The deposit forming tendency of an oil in a combustion chamber is very different from its tendency to form deposits on an intake valve. Higher oil consumption rates and higher base oil boiling ranges tend to increase the deposit level in a combustion chamber.
Technical Paper

Optimization of Cooling Air Flow for Improved Heat Dissipation through Radiator

Environmental Protection Agency (EPA) study indicates that a typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year. The Automotive industry facing a challenge of meeting stringent CO2 emission targets of 95g per kilometer for passenger car application. Thermal efficiency of internal combustion engine is one of the crucial technical parameters, which plays an important role in meeting CO2 emission targets. Global Automotive industry tends to achieve for cleaner, lower emission, low noise & improved performance for automotive products. Engine Overheating is affecting thermal efficiency & thus brake specific fuel consumption of the vehicle. Radiator is one of the critical components in Engine cooling system, which will ensure optimum operating range of internal combustion engine through precise control on coolant flow rate by Thermostat valve. Heat dissipation through radiator is directly proportional to volumetric mass flow rate of atmospheric air.