Progress and recent trends in homogeneous charge compression ignition (HCCI) engines

A premixed charge compression ignition engine, and a control system, is provided which effectively initiates combustion by compression ignition and maintains stable combustion while achieving extremely low nitrous oxide emissions, good overall efficiency and acceptable combustion noise and cylinder pressures. The present engine and control system effectively controls the combustion history, that is, the time at which combustion occurs, the rate of combustion, the duration of combustion and/or the completeness of combustion, by controlling the operation of certain control variables providing temperature control, pressure control, control of the mixture's autoignition properties and equivalence ratio control. The combustion control system provides active feedback control of the combustion event and includes a sensor, e.g. pressure sensor, for detecting an engine operating condition indicative of the combustion history, e.g. the start of combustion, and generating an associated engine operating condition signal. A processor receives the signal and generates control signals based on the engine operating condition signal for controlling various engine components to control the temperature, pressure, equivalence ratio and/or autoignition properties so as to variably control the combustion history of future combustion events to achieve stable, low emission combustion in each cylinder and combustion balancing between the cylinders.

Premixed charge compression ignition engine with optimal combustion control

Demonstrating the Multi Fuel Capability of a Homogeneous Charge Compression Ignition Engine with Variable Compression Ratio

https://www.engr.colostate.edu/~marchese/combustion10/2.pdf

The Homogeneous Charge Compression Ignition (HCCI) is the third alternative for combustion in the reciprocating engine. Here a homogeneous charge is used as in a spark-ignited engine, but the charge is compressed to autoignition as in a diesel. The main difference compared with the Spark Ignition (SI) engine is the lack of flame propagation and hence the independence from turbulence. Compared with the diesel engine, HCCI has a homogeneous charge and hence no problems associated with soot and NOdx formation. Earlier research on HCCI showed high efficiency and very low amounts of NOdx, but HC and CO were higher than in SI mode. It was not possible to achieve high IMEP values with HCCI, the limit being 5 bar. Supercharging is one way to dramatically increase IMEP. The influence of supercharging on HCCI was therefore experimentally investigated. Three different fuels were used during the experiments: iso-octane, ethanol and natural gas. Two different compression ratios were used, 17:1 and 19:1. The inlet pressure conditions were set to give 0, 1, or 2 bar of boost pressure. The highest attainable IMEP was 14 bar using natural gas as fuel at the lower compression ratio. The limit in achieving even higher IMEP was set by the high rate of combustion and a high peak pressure. Numerical calculations of the HCCI process have been performed for natural gas as fuel. The calculated ignition timings agreed well with the experimental findings. The numerical solution is, however, very sensitive to the composition of the natural gas. (Less)

/pdf/supercharged-homogeneous-charge-compression-ignition-1f1w1nz600.pdf

Supercharged Homogeneous Charge Compression Ignition

An internal combustion engine wherein an HC treatment catalyst (12) having the function of adsorbing the HC in the exhaust gas is arranged upstream of the NOx selective reducing catalyst (14), an urea aqueous solution fed from the reducing agent feed valve (15) is arranged upstream of the HC treatment catalyst (12), urea, and NOx contained in the exhaust gas, and HC adsorbed on the HC treatment catalyst 12 are reacted with each other to form intermediate products having cyano groups, oximes, and amino groups, and these intermediate products are sent to the NOx selective reducing catalyst (14).

Exhaust purification device of internal combustion engine

An experimental study on premixed-charge compression ignition gasoline engine

PROBLEM TO BE SOLVED: To provide a technique capable of detecting abnormality in a reduction agent feeding mechanism and to contribute to the suppression of deterioration of exhaust emission and exhaust emission purifying catalyst caused by abnormality in the reduction agent feeding mechanism in an exhaust emission control device for the internal combustion engine equipped with the mechanism feeding a reduction agent in exhaust emission purifying catalyst. SOLUTION: This exhaust emission control device for the internal combustion engine comprises a reduction agent adding nozzle arranged in an exhaust passage located upstream from the exhaust emission purifying catalyst, a reduction agent feeding passage introducing the reduction agent emitted from a reduction agent emission means to the reduction agent adding nozzle, a passage opening and closing valve provided in the reduction agent feeding passage, a pressure detection means provided in the reduction agent feeding passage located downstream from the passage opening and closing means, and an abnormality determining means for determining abnormality on the basis of pressure detected by the pressure abnormality detection means during the opening period of the passage opening and closing valve, and before and after the opening period of the valve.

Exhaust emission purifying device for internal combustion engine

PROBLEM TO BE SOLVED: To control to appropriate values a fuel injection timing and a fuel injection amount of each injection in a multiple fuel injection. SOLUTION: Cylinder pressure sensors 29a to 29d for detecting pressure inside a combustion chamber are respectively provided on cylinders of a diesel engine 1 for performing the multiple fuel injection a plurality of times per one cylinder cycle. An electronic control unit (ECU) 20 of the engine calculates a primary change rate and a secondary change rate with respect to a crank angle of the pressure inside the combustion chamber based on the detected pressure inside the combustion chamber by the cylinder pressure sensors. By comparing the calculated primary and secondary change rates with a previously determined reference value, the electronic control unit 20 controls the fuel injection timing and the fuel injection amount for each injection in a multiple fuel injection to the appropriate values. COPYRIGHT: (C)2004,JPO

Fuel injection control device of internal combustion engine

An object of the present invention is to provide a technology that enables to determine the cetane number of fuel in a state in which it is actually used for running an internal combustion engine with an improved degree of accuracy. A fuel injection for cetane number determination in which a specified quantity of fuel is injected into a combustion chamber during a compression stroke or expansion stroke, is performed (S105) while the internal combustion engine is in a fuel cut state (S101). The cetane number of the fuel is determined based on the time period from a specified time to a time of ignition at which the fuel injected by the fuel injection for cetane number determination is ignited.

Method of determining cetane number of fuel in internal combustion engine

There is provided a compression ignition type gasoline engine operable under a stable lean burn condition with a high compression ratio, and which has a simple construction without using a pre-heating system for an air-fuel mixture. An intake port communicates with a combustion chamber via an opening. The opening is closed by an intake valve. A fuel injection valve is provided in the intake port so as to inject an amount of gasoline inside the intake port within a duration in which the opening is substantially closed by the intake valve. Heat is generated in the mixture in the combustion chamber by means of a high compression ratio so that the mixture is self-ignited only by heat generated by compression. The compression ratio ranges from about 14 to about 20.

Taro Aoyama

Papers

An experimental study on premixed-charge compression ignition gasoline engine

Exhaust emission purifying device for internal combustion engine

Fuel injection control device of internal combustion engine

Method of determining cetane number of fuel in internal combustion engine

Compression ignition type gasoline engine injecting fuel inside intake port during exhaust stroke