Safety Considerations in Retailing Hydrogen

Cracknell, Roger; Alcock, Jane; Rowson, J. J.; Shirvill, L.C.; Ungut, A.

doi:10.4271/2002-01-1928

Cited by 26 publications

(14 citation statements)

References 5 publications

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“…Some of these properties are summarized in Table 1 [12][13][14][15][16]. Hydrogen has very low density and, although its heating value on a mass basis is very high in comparison to other fuels (120 MJ/kg for hydrogen, 43.5 MJ/kg for gasoline), on a volume basis this is the lowest among common fuels (10.2 MJ/m 3 for hydrogen, 216.4 MJ/m 3 for gasoline).…”

Section: Introductionmentioning

confidence: 99%

Hydrogen SI and HCCI Combustion in a Direct-Injection Optical Engine

Rosati¹,

Aleiferis²

2009

SAE Int. J. Engines

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The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under the supervision of the session organizer. This process requires a minimum of three (3) reviews by industry experts. All rights reserved. No part of this publication may 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. ISSN 0148-7191 Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. SAE ABSTRACTHydrogen has been largely proposed as a possible alternative fuel for internal combustion engines. Its wide flammability range allows higher engine efficiency with leaner operation than conventional fuels, for both reduced toxic emissions and no CO 2 gases. Independently, Homogenous Charge Compression Ignition (HCCI) also allows higher thermal efficiency and lower fuel consumption with reduced NO X emissions when compared to Spark-Ignition (SI) engine operation. For HCCI combustion, a mixture of air and fuel is supplied to the cylinder and autoignition occurs from compression; engine is operated throttle-less and load is controlled by the quality of the mixture, avoiding the large fluid-dynamic losses in the intake manifold of SI engines. HCCI can be induced and controlled by varying the mixture temperature, either by Exhaust Gas Recirculation (EGR) or intake air pre-heating. A combination of HCCI combustion with hydrogen fuelling has great potential for virtually zero CO 2 and NO X emissions. Nevertheless, combustion on such a fast burning fuel with wide flammability limits and high octane number implies many disadvantages, such as control of backfiring and speed of autoignition and there is almost no literature on the subject, particularly in optical engines. Experiments were conducted in a singlecylinder research engine equipped with both Port Fuel Injection (PFI) and Direct Injection (DI) systems running at 1000 RPM. Optical access to in-cylinder phenomena was enabled through an extended piston and optical crown. Combustion images were acquired by a highspeed camera at 1° or 2° crank angle resolution for a series of engine cycles. Spark-ignition tests were initially carried out to benchmark the operation of the engine with hydrogen against gasoline. DI of hydrogen after intake valve closure was found to be preferable in order to overcome problems related to backfiring and air displacement from hydrogen's low density. HCCI combustion of hydrogen was initially enabled by means of a pilot port injection of n-heptane preceding the main direct injection of hydrogen, along with intake air preheating. Sole hydrogen fuelling HCCI was finally achieved and made sustainable, even at the low compression ratio of the optical engine by means of closed-valve DI, in synergy with air-pre-heating and negative valve overlap to promote intern...

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Section: Introductionmentioning

confidence: 99%

Hydrogen SI and HCCI Combustion in a Direct-Injection Optical Engine

Rosati¹,

Aleiferis²

2009

SAE Int. J. Engines

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“…A four stroke, single cylinder, spark ignition (SI) engine was also operated with a dual fuel mix of LPG, hydrogen and methane blend in the proportion of 70:30 [16,26,28,29]. Contrasted with other conventional fuels, for example, methane, propane and iso-octane, hydrogen displays a more broader scope of combustibility and has an ignition temperature which is impressively lower than that of its counterparts [17,30,31]. This has been extensively reiterated [21,32,33].…”

Section: Introductionmentioning

confidence: 99%

Use of Gasoline, LPG and LPG-HHO Blend in SI Engine: A Comparative Performance for Emission Control and Sustainable Environment

et al. 2020

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The rising global warming concerns and explosive degradation of the environment requires the mainstream utilization of alternative fuels, such as hydroxy gas (HHO) which presents itself as a viable substitute for extracting the benefits of hydrogen. Therefore, an experimental study of the performance and emission characteristics of alternative fuels in contrast to conventional gasoline was undertaken. For experimentation, a spark ignition engine was run on a multitude of fuels comprising of gasoline, Liquefied petroleum gas (LPG) and hybrid blend of HHO with LPG. The engine was operated at 60% open throttle with engine speed ranging from 1600 rpm to 3400 rpm. Simultaneously, the corresponding performance parameters including brake specific fuel consumption, brake power and brake thermal efficiency were investigated. Emission levels of CO, CO2, HC and NOx were quantified in the specified speed range. To check the suitability of the acquired experimental data, it was subjected to a Weibull distribution fit. Enhanced performance efficiency and reduced emissions were observed with the combustion of the hybrid mixture of LPG with HHO in comparison to LPG: on average, brake power increased by 7% while the brake specific fuel consumption reduced by 15%. On the other hand, emissions relative to LPG decreased by 21%, 9% and 21.8% in cases of CO, CO2, and unburned hydrocarbons respectively. Incorporating alternative fuels would not only imply reduced dependency on conventional fuels but would also contribute to their sustainability for future generations. Simultaneously, the decrease in harmful environmental pollutants would help to mitigate and combat the threats of climate change.

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“…Hydrogen has much wider limits of flammability in air than methane, propane or gasoline and the minimum ignition energy is about an order of magnitude lower than for other combustibles [5,6].…”

Section: Introductionmentioning

confidence: 99%