L.M. Das

Hydrogen engine: research and development (R&D) programmes in Indian Institute of Technology (IIT), Delhi

Active research in the development of hydrogen-fuelled low-emission engines is being pursued at the Engines and Unconventional Fuels Laboratory of the Indian Institute of Technology (IIT), for a period of close to two decades. This paper highlights the significant pursuits and attainments of the research and development (R&D) activities carried out in IIT, Delhi on hydrogen-operated engines. Both spark ignition (SI) and compression ignition engine test rigs have been developed and instrumented for the use of hydrogen fuel. Several existing petroleum-fuelled engine configurations have been modified by taking care to observe that the converted system does not need substantial hardware modifications. Various fuel induction techniques have been experimentally evaluated keeping in view the temperamental combustion characteristic of this fuel. Curative and preventive steps have been adopted and suitable retrofits and subsystems have been installed at the appropriate locations to preclude the possibility of any undesirable combustion phenomena such as backfire, knocking and rapid rate of pressure rise. Performance, emission and combustion characteristics of the systems have been determined. It has been observed that an appropriately designed timed manifold injection system can overcome the problem of backfire in a hydrogen engine. NOx emission level from a hydrogen-operated SI engine can be drastically reduced by way of lean engine operation.

Hydrogen-oxygen reaction mechanism and its implication to hydrogen engine combustion

Combustion of hydrogen with air is receiving increasing attention in the future energy scenario. This paper broadly discusses the hydrogen combustion techniques in various thermal systems. A more elaborate discussion has been made with respect to internal combustion engines where a big role for hydrogen is envisioned particularly in the present context of energy crisis and environmental degradation.

Exhaust emission characterization of hydrogen-operated engine system: Nature of pollutants and their control techniques

Abstract The use of internal combustion engines has so deeply penetrated into our life-style system that it is practically impossible to replace this versatile prime mover. However, the problem of fast depletion of conventional petroleum fuels have, of late, necessitated the search for alternative engine fuels. Besides, in the present day context, a major criterion of judicious selection of an alternative fuel is also based upon its low-emission characteristics. Hydrogen is the cleanest known alternative engine fuel. This paper discusses the nature and formation mechanism of different types of pollutants emitted from a hydrogen operated engine system. The concentration level of various pollutants emitted from both the spark ignition and compression ignition engine system configurations has been described. Practical engine operating conditions to bring down the pollutants to acceptable limits have also been identified.

On-board hydrogen storage systems for automotive application

The potential of hydrogen in the emerging energy-environment scene as a promising alternative for simultaneously solving the two problems concerning the protection of the environment and optimum energy utilization, has by now, been very clearly understood. However, while considering hydrogen for automotive applications two important factors must be carefully viewed. Firstly, the fuel metering system should be capable of supplying the desired quantity of fuel to the engine at the appropriate point in the engine cycle so as to ensure sustained engine operation without any symptoms of undesirable combustion. The other practical aspect which has delayed the regular implementation and commercialization of hydrogen fuel for vehicular application centres round the problem of onboard storage. This paper discusses various possible storage techniques for hydrogen use in the automobile sector.

Exhaust gas recirculation for NOx control in a multicylinder hydrogen-supplemented S.I. engine

Abstract This paper describes the results of an experimental investigation carried out on a hydrogen-supplemented multicylinder spark ignition (S.I.) engine to control the level of NOx (oxides of nitrogen) emission by adopting exhaust gas recirculation (EGR). It was observed that the NOx level was substantially reduced over a wide range of engine operation conditions. Performance characteristics of the system were also evaluated corresponding to these operating conditions.

Exergy Analysis of Hydrogen-Fueled Spark Ignition Engine Based on Numerical Investigations

Hydrogen fuelled IC engines (H2ICEs) have been considered as one of the most promising systems for pollution free transportations and their performance and combustion merits have been extensively discussed in the literature. However, studies related to these discussions have largely been linked to first-law analysis. On other hand, second-law of thermodynamics coupled with first-law, also known as exergy analysis, can give better insight into the engine performances. Bearing it in mind, this work presents second-law quantification of hydrogen engine processes and sub-processes, which helps to understand its true potential to deliver the output and simultaneously estimates various losses. This study quantifies different process inefficiencies in terms of irreversibilities thereby identifying the gaps to be addressed for further improvements. A computational fluid dynamics model has been prepared to simulate hydrogen-fueled spark-ignition engine (H2SIE) operations and second-law equations have been coupled to ascertain different exergy terms. Present study shows that combustion process is the biggest source of irreversibility in IC engines. It has also been found that the level of irreversibility for a hydrogen-operated engine is substantially lesser as compared to that with gasoline engine under identical ranges of operating conditions. Combustion irreversibilities for H2SIE and gasoline engine were found to be 15% and 23.6% of the total input fuel exergy respectively. Moreover, significant increase in second-law efficiency for H2SIE as 44.4% compared to 36.8% that for gasoline engines has been found. Another important conclusion from this work includes exergy distribution for H2SIE, which is considerably diverse from gasoline engine operation. It indicates that optimization and improvements of different H2SIE processes require specific attentions; nevertheless, show much better ability to deliver.