1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2010 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside US
4、A) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR5373AAEROSPACEINFORMATIONREPORTAIR5373 REV. A Issued 1999-01 Revised 2010-08Superseding AIR5
5、373 (R) Fuels in Ground Support Equipment (Other Than Gasoline or Diesel) RATIONALEAs part of the 5 year review, Biofuels update was added, including ASTM and NE standards, concerns with converting in-use equipment to biodiesel. Also added eas diodiesel information on storage tanks and lomg term sto
6、rage. Updates on other fuels and their use in Tier 3 engines was also included. TABLE OF CONTENTS 1. SCOPE 21.1 Purpose . 21.2 Field of Application 22. APPLICABLE DOCUMENTS 23. TERMINOLOGY 23.1 SPARK IGNITION ENGINE 23.2 COMPRESSION IGNITION ENGINE . 23.3 STOICHIOMETRIC AIR/FUEL RATIO 23.4 LEAN AIR/
7、FUEL RATIO . 23.5 RICH AIR/FUEL RATIO 23.6 CARBON MONOXIDE (CO) . 23.7 HYDROCARBON (HC) . 33.8 OXIDES OF NITROGEN (NOx) 33.9 SULPHUR OXIDES (SOx) 33.10 PARTICULATE EMISSION . 33.11 ALTERNATIVE FUEL . 34. COMPRESSION IGNITION ENGINES . 34.1 Biodiesel: . 34.2 Clean Diesel 44.3 Gaseous Fuels 44.4 Jet A
8、 45. SPARK IGNITED ENGINES . 45.1 Natural Gas . 45.2 Liquid Petroleum Gas . 45.3 Methanol . 55.4 Ethanol 55.5 Reformulated Gasoline . 56. ELECTRICITY . 57. CLIMATE CONCERNS . 58. NOTES 5Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5373A Pag
9、e 2 of 51. SCOPE This SAE Aerospace Information Report (AIR) is intended as a source of comparative information and is subject to change to keep pace with experience and technical advances. This document describes currently used fuels and fuels which may be used in the future. Conventional gasoline
10、and diesel fuels are intentionally omitted from this document. 1.1 Purpose The purpose of this document is to provide basic information regarding fuels which can be used in aircraft ground support equipment. This document is recommended for use by those engaged in the design, selection, or maintenan
11、ce of ground support equipment, and their fuel systems. 1.2 Field of Application This document is applicable to spark ignition or compression ignition engines, and battery powered electric motors. CAUTION: Always follow the specific recommendations and guidelines of the engine manufacturer, regardin
12、g suitable fuel types for a particular engine. The use of unauthorized fuels may void the warranty and result in damage or injury. 2. APPLICABLE DOCUMENTS There are no referenced publications specified herein. 3. TERMINOLOGY 3.1 SPARK IGNITION ENGINE An internal combustion engine utilizing a positiv
13、e ignition system to ignite the air/fuel charge. All gasoline fueled engines are of the spark ignited type. 3.2 COMPRESSION IGNITION ENGINE An internal combustion engine utilizing high compression to ignite the air/fuel charge. All diesel fueled engines are of the compression ignition type. 3.3 STOI
14、CHIOMETRIC AIR/FUEL RATIO The ideal air/fuel ratio, resulting in complete combustion of all fuel and air. This ratio is dependent on fuel type. 3.4 LEAN AIR/FUEL RATIO More air and less fuel than the stoichiometric air/fuel ratio. 3.5 RICH AIR/FUEL RATIO More fuel and less air than the stoichiometri
15、c air/fuel ratio. 3.6 CARBON MONOXIDE (CO) Carbon monoxide is produced when combustion takes place with insufficient oxygen. Carbon monoxide emissions can be a concern in spark ignited engines as they are typically operated near stoichiometric at part load and rich at full load. Carbon monoxide emis
16、sions are lower for diesel engines as they generally operate in a lean condition. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5373A Page 3 of 53.7 HYDROCARBON (HC) The HC portion of exhaust gas emissions represents incomplete combustion of
17、 fuel. Some HC classes, such as methane, are essentially inert and do not react to form smog. Other HC classes react to form smog. 3.8 OXIDES OF NITROGEN (NOx)Both nitric oxide (NO) and nitrogen dioxide (NO2) are collectively grouped as oxides of nitrogen (NOx). NOx is a primary constituent of smog.
18、 Diesel and gasoline powered engines have similar concentrations of NOx. 3.9 SULPHUR OXIDES (SOx)Both sulphur dioxide (SO2) and sulphur trioxide (SO3) are collectively grouped as SOx. SOx is the primary cause of acid rain.3.10 PARTICULATE EMISSION Unburned hydrocarbon emission in the solid form of s
19、oot. Diesel engines have significant particulate emissions. 3.11 ALTERNATIVE FUEL A specific fuel listed in a regulatory document (i.e., Clean Air Act in the U.S., etc.) as an approved alternative fuel. Not allfuels listed in this document are classified as alternative fuels. 4. COMPRESSION IGNITION
20、 ENGINES 4.1 Biodiesel: Biodiesel is a direct substitute to diesel fuel consisting of a blend of Fatty Acid Methyl Esters (FAME), such as processed Rapeseed, typically used in Europe or Soybean oil, typically used in North America and standard diesel fuel. This fuel reduces particulate emissions, HC
21、 and CO but also increases NOx emissions. The current biodiesel specs are issued under EN 14214 in Europe and ASTM D6751 in North America. These specifications define only the biodiesel (B100) as the blend componenet used with diesel fuel. They are not applicable to the fuel blends purchased by end
22、users. Most engine manufacturers have been allowing up to a maximum of B5 (5% biodiesel and 95% diesel). Concerns with quality and stability have limited approval of higher blends. With recent changes to ASTM D6751 standard in North America that now includes an important stability specification for
23、B100 biodiesel, availability of quality fuels from BQ-9000 certified marketers and accredited producers is growing rapidly. Many engine manufacturers are now starting to approve B20 biodiesel blends. Because of these rapid changes it is suggested that the engine manufacturer should be contacted for
24、current allowed biodiesel blends. There are also potential issues with biodiesel that should be considered: 4.1.1 Converting existing equipment to biodiesel can cause fuel leaks due to the reaction of some types of seal and hose material to biodiesel. This is not an issue with new equipment as engin
25、e manufacturers have changed seal and hose material to accommodate biodiesel. The biodiesel also acts as a cleaning agent which may cause fuel filter plugging when converting current equipment. 4.1.2 Storage is a potential issue with biodiesel. It is recommended to use Biodiesel within six months of
26、 its manufacture. Biodiesel has poor oxidation stability, which can cause long term storage problems. 4.1.3 Biodiesel has a natural affinity to water unlike diesel fuel. If switching to biodiesel is being considered, steps should be taken to ensure there is no standing water at the bottom of the fue
27、l storage tank to be used. Biodiesel water absorption is so complete that fuel filters have a hard time removing the water, creating potential for engine damage.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5373A Page 4 of 54.1.4 B100 biodie
28、sel has 7-10% less energy per gallon compared to conventional diesel fuel. This is mitigated to some extent when mixed with diesel fuel. 4.2 Clean Diesel Clean diesel is a direct substitute to diesel fuel, and has a significantly reduced sulfur content, relative to standard dieselfuel. Clean Diesel
29、in Europe is the equivalent to Ultra Low Sulfur Diesel (ULSD) in North America. SOx and particulate emissions are reduced when using this type of fuel. Current specifications for on-highway diesel fuel is 15PPM SOx in N.A. and 10 PPM in Europe and 500PPM SOX for off-highway fuel. Clean and ULSD dies
30、el fuels are more prone to oxidation and have less lubricity than previous diesel fuels. It is recommended to consult fuel supplier to determine if additives are needed to maintain fuel quality. 4.3 Gaseous Fuels Gaseous fuels (natural gas and LPG) can be burned in compression ignition engines by ut
31、ilizing a fumigation system. Fumigation involves a lean mixture of gaseous fuel and a small amount of diesel fuel. Gaseous fuels do not have the self-ignition characteristics of diesel fuel. A spark plug or the diesel fuel is added to provide ignition of the air/fuel charge. Dual fuel engines can be
32、 designed to work on mostly diesel fuel or mostly gaseous fuel.4.3.1 Alcohols Alcohol fuels (methanol and ethanol) can be used with direct injection, if the compression ratio is raised, and a glow plug is added for part throttle conditions. Alcohol can also be blended with diesel, via fumigation int
33、o the air intake system, similar to the gaseous fuels. Alcohol fuels have escalated fire and explosion hazards relative to diesel fuel 4.4 Jet A Jet A can be used as a direct replacement for standard diesel fuel. Jet A has lower lubricity than diesel fuel and may require the use of an upgraded fuel
34、system, or a fuel additive to retain acceptable fuel system life. Engine power is reduced by approximately 5% compared to standard diesel fuel. Jet A has higher SOX content that the current EPA mandated levels for both automotive and off-highway diesel fuels. Historically Jet A has been a common sub
35、stitute for diesel fuel in GSE. Changes to regulations in the last several years have severely curtailed this practice. 5. SPARK IGNITED ENGINES 5.1 Natural Gas Natural gas is available as a liquid or vapor. Low cost, abundance and low emissions are the major advantages of natural gas. Unburned meth
36、ane and NOx are the principle pollutants in most applications. Engine power is reduced approximately 15% compared to standard gasoline fuel. Diesel engine derived natural gas engines can match the diesel engine horsepower. In some applications, it is favorable to operate a dual fuel arrangement. Gas
37、oline and natural gas fuel systems are installed on the same engine, although only one can be used at a time. 5.2 Liquid Petroleum Gas One of the most common alternative fuels is liquefied petroleum gas, also known as LPG. Since most LPG fuel systems operate in a lean mode, HC and CO emission levels
38、 are lower and NOx is slightly higher when compared to gasoline. Engine power is reduced approximately 5% compared to standard gasoline fuel. In some applications, it is favorable to operate a dual fuel arrangement. Gasoline and LPG fuel systems are installed on the same engine, although only one ca
39、n be used at a time. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR5373A Page 5 of 55.3 Methanol Methanol is an alcohol which can be used as a fuel. Methanol is commercially available as a majority blend of methanol and some gasoline. This f
40、uel can be produced from natural gas, coal, or biogas. Biogas is corrosive to certain metals, particularly those used in some engine bearings. Methanol can cause deterioration of fuel handling components. Methanol is also highly toxic if swallowed.5.4 Ethanol Ethanol is an alcohol fuel with similar
41、properties to methanol but not as toxic or corrosive. It is produced through fermentation of grain in the US or sugar cane in other countries. Due to its high production costs, there are questions as to the net engergy results with studies claiming negative and positive energy balances. Gasohol, a b
42、lend of 90% gasoline and 10% ethanol, is available in the U.S. because of government incentives. Traditional methods of ethanol production require more energy than is released when the fuel is burned.Ethanol is not considered a safe blending material with diesel fuel due to its volatilty characteris
43、tics. This volitilty leads to flammable ethonal vapors in the head space of the tank which could cause an explosion. Diesel fuel tanks are not designed to manage flammable vapor like gasoline fuel tanks are.5.5 Reformulated Gasoline Reformulated gasoline is a gasoline blend with reduced benzene and
44、added oxygenates. The goal of reformulated gasoline is to reduce VOC emissions, toxins, and NOx. These fuels are mandated in the most severe ozone non-attainment areas in the United States. 6. ELECTRICITY Electric powered vehicles produce no emissions at the point of operation. Electric powered vehi
45、cles require a high capacity electrical infrastructure to accommodate the power requirements of chargers. 7. CLIMATE CONCERNS Under low ambient temperatures, certain fuels will not flow properly through the fuel system. Check with the fuel supplier for recommendations on suitable temperature limits
46、of a specific fuel. Startability may also be affected. Starting aids are available to assist in cold weather starts. Certain applications may require a dual fuel arrangement to assure reliable starting under extremely low ambient temperatures. 8. NOTES 8.1 A change bar (|) located in the left margin
47、 is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and
48、 (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY SAE SUBCOMMITTEE AGE-2C, VEHICLE MAINTENANCE AND AIRCRAFT SERVICING OF COMMITTEE AGE-2, AIR CARGO AND AIRCRAFT GROUND EQUIPMENT AND SYSTEMS Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
