HCCI Operability Limits: The Impact of Refinery Stream Gasoline Property Variation

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Joshua S. Lacey ◽  
Zoran S. Filipi ◽  
Sakthish R. Sathasivam ◽  
William J. Cannella ◽  
Peter A. Fuentes-Afflick
Keyword(s):  
Thermal Conditions ◽  
The United States ◽  
High Load ◽  
Fuel Properties ◽  
Research Octane Number ◽  
Property Variation ◽  
Hcci Combustion ◽  
Load Limit ◽  
Low Load ◽  
The Impact

Homogeneous charge compression ignition (HCCI) combustion is highly dependent on in-cylinder thermal conditions favorable to autoignition, for a given fuel. Fuels available at the pump can differ considerably in composition and autoignition chemistry; hence strategies intended to bring HCCI to market must account for the fuel variability. To this end, a test matrix consisting of eight gasoline fuels composed of blends made solely from refinery streams was investigated in an experimental, single cylinder HCCI engine. The base compositions were largely representative of gasoline one would expect to find across the United States, although some of the fuels had slightly lower average octane values than the ASTM minimum specification of 87. All fuels had 10% ethanol by volume included in the blend. The properties of the fuels were varied according to research octane number (RON), sensitivity (S=RON-MON) and the volumetric fractions of aromatics and olefins. For each fuel, a sweep of the fuelling was carried out at each speed from the level of instability to excessive ringing to determine the limits of HCCI operation. This was repeated for a range of speeds to determine the overall operability zone. The fuels were kept at a constant intake air temperature during these tests. The variation of fuel properties brought about changes in the overall operating range of each fuel, as some fuels had more favorable low load limits, whereas others enabled more benefit at the high load limit. The extent to which the combustion event changed from the low load limit to the high load limit was examined as well, to provide a relative criterion indicating the sensitivity of HCCI range to particular fuel properties.

HCCI Operability Limits: The Impact of Refinery Stream Gasoline Property Variation

2012 ◽  
Author(s):  
Joshua S. Lacey ◽  
Sakthish R. Sathasivam ◽  
Zoran S. Filipi ◽  
William J. Cannella ◽  
Peter A. Fuentes-Afflick
Keyword(s):  
Thermal Conditions ◽  
The United States ◽  
High Load ◽  
Fuel Properties ◽  
Property Variation ◽  
Hcci Combustion ◽  
Auto Ignition ◽  
Load Limit ◽  
Low Load ◽  
The Impact

HCCI combustion is highly dependent on in-cylinder thermal conditions favorable to auto-ignition, for a given fuel. Fuels available at the pump can differ considerably in composition and auto-ignition chemistry, hence strategies intended to bring HCCI to market must account for the fuel variability. To this end, a test matrix consisting of eight gasoline fuels composed of blends made solely from refinery streams was investigated in an experimental, single cylinder HCCI engine. The base compositions were largely representative of gasoline one would expect to find across the United States, although some of the fuels had slightly lower average octane values than the ASTM minimum specification of 87. All fuels had 10% ethanol by volume included in the blend. The properties of the fuels were varied according to research octane number (RON), sensitivity (S=RON−MON) and the volumetric fractions of aromatics and olefins. For each fuel, a sweep of the fuelling was carried out at each speed from the level of instability to excessive ringing to determine the limits of HCCI operation. This was repeated for a range of speeds to determine the overall operability zone. The fuels were kept at a constant intake air temperature during these tests. The variation of fuel properties brought about changes in the overall operating range of each fuel, as some fuels had more favorable low load limits, whereas others enabled more benefit at the high load limit. The extent to which the combustion event changed from the low load limit to the high load limit was examined as well, to provide a relative criterion indicating the sensitivity of HCCI range to particular fuel properties.

Expanding the Low Load Limit of HCCI Combustion Process Using EIVO Strategy in a 4VVAS Gasoline Engine

2012 ◽  
Author(s):  
Tao Chen ◽  
Hui Xie ◽  
Le Li ◽  
Weifei Yu ◽  
Lianfang Zhang ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
Combustion Process ◽  
Hcci Combustion ◽  
Load Limit ◽  
Low Load

Impact of Refinery Stream Gasoline Property Variation on Load Sensitivity of the HCCI Combustion

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Joshua S. Lacey ◽  
Zoran S. Filipi ◽  
Sakthish R. Sathasivam ◽  
Richard J. Peyla ◽  
William Cannella ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Performance Metrics ◽  
Thermal Environment ◽  
Energy Content ◽  
Combustion Process ◽  
Engine Performance ◽  
The United States ◽  
Specific Fuel Consumption ◽  
Property Variation ◽  
Hcci Combustion

The homogeneous charge compression ignition (HCCI) combustion process is highly reliant upon a favorable in-cylinder thermal environment in an engine, for a given fuel. Commercial fuels can differ considerably in composition and autoignition chemistry; hence, strategies intended to bring HCCI to market must account for this fuel variability. To this end, a test matrix consisting of eight gasoline fuels comprised of blends made solely from refinery streams were run in an experimental, single cylinder HCCI engine. All fuels contained 10% ethanol by volume and were representative of a cross section of fuels one would expect to find at gasoline pumps across the United States. The properties of the fuels were varied according to research octane number (RON), sensitivity (S = RON-MON), and volumetric content of aromatics and olefins. For each fuel, a sweep of load (mass of fuel injected per cycle) was conducted and the intake air temperature was adjusted in order to keep the crank angle of the 50% mass fraction burned point (CA50) constant. By analyzing the amount of temperature compensation required to maintain constant combustion phasing, it was possible to determine the sensitivity of HCCI to changes in load for various fuels. In addition, the deviation of fuel properties brought about variations in important engine performance metrics like specific fuel consumption. Though the injected energy content per cycle was matched at the baseline point across the test fuel matrix, thermodynamic differences resulted in a spread of specific fuel consumption for the fuels tested.

Impact of Refinery Stream Gasoline Property Variation on Load Sensitivity of the HCCI Combustion

2012 ◽  
Author(s):  
Joshua S. Lacey ◽  
Sakthish R. Sathasivam ◽  
Zoran S. Filipi ◽  
Richard J. Peyla ◽  
William J. Cannella ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Performance Metrics ◽  
Thermal Environment ◽  
Energy Content ◽  
Combustion Process ◽  
Engine Performance ◽  
The United States ◽  
Specific Fuel Consumption ◽  
Property Variation ◽  
Hcci Combustion

The HCCI combustion process is highly reliant upon a favorable in-cylinder thermal environment in an engine, for a given fuel. Commercial fuels can differ considerably in composition and auto-ignition chemistry, hence strategies intended to bring HCCI to market must account for this fuel variability. To this end, a test matrix consisting of eight gasoline fuels comprised of blends made solely from refinery streams were run in an experimental, single cylinder HCCI engine. All fuels contained 10% ethanol by volume and were representative of a cross-section of fuels one would expect to find at gasoline pumps across the United States. The properties of the fuels were varied according to research octane number (RON), sensitivity (S=RON-MON) and volumetric content of aromatics and olefins. For each fuel, a sweep of load (mass of fuel injected per cycle) was conducted and the intake air temperature was adjusted in order to keep the crank angle of the 50% mass fraction burned point (CA50) constant. By analyzing the amount of temperature compensation required to maintain constant combustion phasing, it was possible to determine the sensitivity of HCCI to changes in load for various fuels. In addition, the deviation of fuel properties brought about variations in important engine performance metrics like specific fuel consumption. Though the injected energy content per cycle was matched at the baseline point across the test fuel matrix, thermodynamic differences resulted in a spread of specific fuel consumption for the fuels tested.

Characterization of Engine Control Authority on HCCI Combustion as the High Load Limit is Approached

2013 ◽  
Vol 6 (1) ◽  
pp. 553-568 ◽  
Author(s):  
James P. Szybist ◽  
K. Dean Edwards ◽  
Matthew Foster ◽  
Keith Confer ◽  
Wayne Moore
Keyword(s):  
High Load ◽  
Engine Control ◽  
Hcci Combustion ◽  
Load Limit ◽  
Control Authority

scholarly journals High Load With Lower Repetitions vs. Low Load With Higher Repetitions: The Impact on Asymmetry in Weight Distribution During Deadlifting

2020 ◽  
Vol 2 ◽  
Author(s):  
Mitchel C. Whittal ◽  
Derek P. Zwambag ◽  
Luke W. Vanderheyden ◽  
Greg L. McKie ◽  
Tom J. Hazell ◽  
...  
Keyword(s):  
Weight Distribution ◽  
High Load ◽  
Low Load ◽  
The Impact

Demonstrating Nutrient Cost Gradients: A Brooklyn Case Study

2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi
Keyword(s):  
Low Income ◽  
Energy Content ◽  
Food Selection ◽  
The United States ◽  
United States Department ◽  
Micronutrient Deficiencies ◽  
Caloric Density ◽  
Low Income Families ◽  
The Cost ◽  
The Impact

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.

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