1、 Reference number ISO/TR 15403-2:2006(E) ISO 2006TECHNICAL REPORT ISO/TR 15403-2 First edition 2006-08-15 Natural gas Natural gas for use as a compressed fuel for vehicles Part 2: Specification of the quality Gaz naturel Gaz naturel pour usage comme carburant comprim pour vhicules Partie 2: Spcifica
2、tion de la qualit ISO/TR 15403-2:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performin
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5、tariat at the address given below. ISO 2006 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the add
6、ress below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2006 All rights reservedISO/TR 15403-2:2006(E) ISO 2006 All righ
7、ts reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Water content 2 4 Sulfur compounds 2 5 Particulate matter 3 6 Higher hydrocarbons 3 7 CO 2 . 3 8 Free oxygen. 3 9 Glycol/Methanol 4 10 Oil content . 4 Annex A (informative) Corrosive components 6 ISO/TR
8、 15403-2:2006(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each m
9、ember body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
10、Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards a
11、dopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from tha
12、t which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it pr
13、ovides are considered to be no longer valid or useful. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 15403-2 was prepared by Technical Commi
14、ttee ISO/TC 193, Natural gas. ISO/TR 15403 consists of the following parts, under the general title Natural gas Natural gas for use as a compressed fuel for vehicles: Part 1: Designation of the quality Part 2: Specification of the quality (Technical Report) ISO/TR 15403-2:2006(E) ISO 2006 All rights
15、 reserved v Introduction In 2000, ISO 15403, Natural gas Designation of the quality of natural gas for use as a compressed fuel for vehicles, was published. The word “designation” was used in the title of this International Standard as no range of values, or limits could be stated as specifications
16、or requirements for natural gas components in quality standards. This question was resolved during development of ISO 13686, Natural gas Quality designation, which pertains to natural gas as supplied through transmission and distribution piping systems. The rationale for this stance is that, since n
17、atural gas is a natural product and does not need the sophisticated processing such as applied to crude oil, it is not possible to specify an exact gas quality. This is especially applicable to natural gas engines as enabled by precise fractionating in crude oil distillation (petrol/diesel). During
18、the review of ISO/CD 15403-1, comments regarding the need for “specifications” instead of “designation” were received from several countries including the Netherlands, Sweden and the United States. In addition, the text was circulated to CEN/TC 326, Gas Supply for Natural Gas Vehicles, which conclud
19、ed that “the actual version is too general and does not help in the matter”. Therefore, ISO/TC 193 decided to prepare a Technical Report as ISO/TR 15403-2 to give the existing information on specifications of compressed natural gas. TECHNICAL REPORT ISO/TR 15403-2:2006(E) ISO 2006 All rights reserve
20、d 1 Natural gas Natural gas for use as a compressed fuel for vehicles Part 2: Specification of the quality 1 Scope This Technical Report addresses the specifications of natural gas as a compressed fuel for vehicles as an addendum to ISO 15403-1. Specifically, it is intended to satisfy requests for q
21、uantitative data. The following are critical items regarding gas composition: water content; sulfur compounds; particulate matter; higher hydrocarbons; CO 2 ; free oxygen; glycol/methanol; oil content corrosive components; This Technical Report pertains only to compressed natural gas as it enters th
22、e fuel containers on the vehicle. It does not apply to the natural gas delivered to a refuelling station. Any alteration of the natural gas supply composition to meet these specifications is clearly the responsibility of the refuelling station operator. 2 Normative references The following reference
23、d documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 15403-1:2006, Natural gas Natural gas for use as a compressed fuel f
24、or vehicles Part 1: Designation of the quality ISO 18453:2004, Natural gas Correlation between water content and water dew point SAE J1616, Recommended Practice for Compressed Natural Gas Vehicles ISO/TR 15403-2:2006(E) 2 ISO 2006 All rights reserved3 Water content ISO 15403-1 clearly requires that
25、the dew point of the compressed natural gas in the containers shall be low enough to preclude the formation of liquid under any circumstances of pressure and temperature. It gives refuelling station operators the opportunity to meet this condition in accordance with local geographic conditions. A gr
26、aph of water content of natural gases as a function of absolute pressure and temperature is provided in ISO 15403-1:2006, Figure E.1. From this graph, the dew point and water content, expressed in grams per cubic metre, can be determined for any pressure up to 25 000 kPa and ambient temperature from
27、 30 C to + 40 C. Reference is made to ISO 18453. A refuelling station operator can determine the lowest ambient temperature recorded for his area and set a water content accordingly. The formation of hydrates in the container or piping should be prevented. In a Note to Figure E.1 in ISO 15403-1:2006
28、, a water content of less than 30 mg/m 3is stated as a satisfactory level for expected pressure and temperature. This can be considered a specification and the system shall be fitted and maintained with dryers to achieve such a condition. In the presence of free water, the following metal components
29、, unless they are manufactured from corrosion- resistant materials, are prone to corrosion: a) storage cylinder in the vehicle; b) stationary storage cylinder in the refuelling station; c) piping; d) refuelling coupling; e) valves in general; f) regulator; g) injection system. Another safety feature
30、 is the fact that a refuelling compressor breaks down if liquid water is present. See Table 1 for general specifications. 4 Sulfur compounds In the presence of sulfur, the following metal components, unless they are manufactured from corrosion- resistant materials, are prone to corrosion: a) storage
31、 cylinder in the vehicle; b) stationary storage cylinders of the refuelling station; c) piping; d) refuelling coupling; e) valves in general; f) regulator; g) injection systems. ISO/TR 15403-2:2006(E) ISO 2006 All rights reserved 3 If there is water present, any amount of sulfur can increase corrosi
32、on. The limit value for mass concentration of total sulfur is 120 mg/m 3 . This amount of total sulfur avoids excessive exhaust-catalyst poisoning. The limits for the sulfur in specific sulfur components should be sulfur in the form of H 2 S u 5 mg/m 3and sulfur in the form of mercaptans u 15 mg/m 3
33、 . See Table 1 for general specifications. 5 Particulate matter Pipeline gas is technically free of dust and dirt, but it is a long-standing practice to incorporate filters into gas appliances. Many utilities use filters or screens upstream of meters for debris protection. Good practice dictates the
34、 installation of filters or screens in advance of compressors at refuelling stations. It is essential to keep debris out of the vehicle containers. To this purpose, SAE J1616 recommends at least a 5 m filter on the fuel line feeding the vehicle container. This usage constitutes a specification for d
35、ebris control. Of course, such filters shall be maintained and changed as necessary. Recommended filters include the following: refuelling connector 40 m; injection system/regulator 5 m; injectors 1 m. See Table 1 for general specifications. 6 Higher hydrocarbons A safety feature is the fact that a
36、compressor can break down if hydrocarbon liquid is present. All rubber components can be affected. The maximum allowable mole fraction of propane and butane that corresponds to 1 % of the original gaseous volume gives an indication for the liquid condensation volume for various low ambient temperatu
37、res and worst-gas-storage pressure conditions. This is given in ISO 15403-1:2006, Annex A. See Table 1 for general specifications. 7 CO 2In the presence of liquid water, any CO 2can be converted to an acid compound that can cause corrosion. All metal components can be affected, especially the storag
38、e cylinder. A volume-fraction limit of 0,03 is recommended. See Table 1 for general specifications. 8 Free oxygen The volume-fraction limit of free oxygen is put at 0,03. See Table 1 for general specifications. ISO/TR 15403-2:2006(E) 4 ISO 2006 All rights reserved9 Glycol/Methanol The natural gas in
39、 the vehicle shall not contain glycol or methanol. 10 Oil content Studies have shown that some level of oil content (carried over from compressors) is beneficial, if not essential, to lubricate the fuel system. However, too much oil is detrimental, since it can clog up elements of the fuel system an
40、d even displace volume in the container. The build-up of oil in the container can lead to possible large oil circulation in the fuel circuit of the vehicle. NOTE Just exactly what is the minimum and maximum range of oil content, and how, in fact, to measure the oil content has not yet been determine
41、d. As of the publication date of this Technical Report, studies are underway on this problem in the United States and Europe. Thus, no specifications can be given at the time of publication of this Technical Report. However, years of OEM-experience suggests a range of (70 to 200) %(V/V) 10 4 . Refue
42、lling station operators shall pay attention to the use of oil by their compressors. Any increase in usage can be cause for concern. A build-up of oil in station holding tanks can be detrimental, especially if high flow volumes tend to draw oil into vehicle containers. Filters and dryers can retain o
43、il as well as water and shall be maintained regularly by station operators. ISO/TR 15403-2:2006(E) ISO 2006 All rights reserved 5 Table 1 Recommended specifications DeviceaWater content 30 mg/m 3 at 20 MPa and 20 C Sulfur compounds total S 120 mg/m 3Particulate matter Oil %(V/V) 10 4 Hydro- carbons
44、liquid 1 % liquid at lowest temperature CO 2 3 %(V/V) Free oxygen Methanol/ Glycol Check valve a a 200 na a na na 0 Manual valve a a 200 na a na na 0 Cylinder valve a a 200 na a na na 0 Service valve a a 200 na a na na 0 Gas air mixer a a 40 na na na na 0 Pressure- measurement device a a 40 na a na
45、na 0 Pressure regulator a a 40 na a (important) na na 0 Automatic valve a a 200 na a na na 0 Miscellaneous components a a na na na na na 0 Gastight housing a a na na na na na 0 Ventilation hose a a na na a na na 0 Fuel tube a a na na na na na 0 Fuel hose a a na na na na na 0 Pressure relief device a
46、 a 200 na a na na 0 Cylinder a a na na na na na 0 Gas flow adjuster a a 200 na na na na 0 Pressure relief valve a a 40 na a na na 0 Filter a a na na a na na 0 Excess flow valve a a 40 na a na na 0 Injector a a 1 70 to 200 na na na 0 Receptacle a a 400 na na na na 0 Nozzle a a 400 na na na na 0 aa =
47、applicable, na = not applicable ISO/TR 15403-2:2006(E) 6 ISO 2006 All rights reservedAnnex A (informative) Corrosive components Natural gas can contain certain components e.g. carbon dioxide, sulfur compounds and oxygen, that, when combined with free water, form corrosive components. The quantities
48、of CO 2 , H 2 S, and O 2vary from one natural gas composition to another. No specifications or requirements have been established internationally, or even within countries, with some exceptions. Thus, a basic premise of ISO 15403 (all parts) is to prevent corrosive compounds from forming in the vehi
49、cle container and fuel system by eliminating liquid water. Ergo, the very stringent limitations on dew point and water content. The make-up of natural gas varies considerably around the world and within countries. Removal of corrosive compounds to some minimal level would be a very expensive and impractical approach. Experience over the decades of natural gas usage has resulted in general, rule-of-thumb, maximum acceptable values, but they are not universally applied. F