Experimental Study of the Performance of a Stationary Diesel Engine Generator with Hydrogen Supplementation

Abstract

Recent claims of engine efficiency improvement via hydrogen generated by small electrolyzers have been made by numerous businesses selling these devices. The technical literature indicates that using hydrogen in gasoline internal combustion results in some improvement in engine emissions. Literature with detailed experimental results with hydrogen supplementation in a stationary diesel engine generator set was not found. This paper presents the results of the experiment that was conducted on a 125 kW stationary diesel engine generator set by addition of supplementary hydrogen in the intake air stream. The hydrogen was from a compressed hydrogen tank, and the testing was completed in two separate runs, the first with H 2 /air ratios by volume between 0 and 0.7% and the second with H 2 /air ratios by volume between 0 and 2.3%. The upper limits of these ranges are far above the levels provided by the small electrolyzers currently being sold. The experiments were conducted at a constant load of 56 kW and 1200 rpm. It was observed that the amount of fuel energy consumed (the sum of the diesel and H 2 fuel values) remained constant as the engine was run at constant load and that no increase in thermal efficiency occurred. Net indicated work per cycle per cylinder was measured using an in-cylinder pressure sensor. The net indicated work per cycle per cylinder was nearly constant throughout each experiment. Some combustion parameters, such as start of ignition and end of premixed combustion, have been checked and showed no significant variations due to the added hydrogen in the intake air stream. O 2 , SO 2 , and CO emissions decreased as the hydrogen in intake stream increased. As the hydrogen flow rate in intake air increased NO 2 emissions increased, NO emissions and NO x emissions decreased up to 50 dm 3 /min of H 2 and then increased up to 150 dm 3 /min of H 2 . All the above-mentioned changes are relatively small amounts. These results indicate that there is no change in engine efficiency with the addition of hydrogen and only minor changes in emissions. However, the efficiency of the engine system (the engine and its auxiliary components) may increase with the added hydrogen, if the hydrogen is generated from the engine waste energy, such as engine exhaust waste heat.

Influence of oxygen enriched hydrogen gas as a combustion catalyst in a DI diesel engine operating with varying injection time of a diesel fuel

“…This might be due to the high diffusion co-efficient of the hydrogen present in the gas mixture and its low activation energy, resulting in efficient combustion. 29 This conrms the result obtained by Avadhanula et al 30 in their investigation on hydrogen fueled engines. At 27 BTDC, the excess oxygen emitted from the engine was lower as compared to other injection timed operations.…”

Decarbonisation of heavy-duty diesel engines using hydrogen fuel: a review of the potential impact on NOx emissions

“…Multiple studies in Table 1 show that it is possible to congure operating conditions to retain or improve combustion performance and efficiency on hydrogen blending. [46][47][48][49][50][51] Although NO x is the primary pollutant of interest in our review, it is important to cnsider other point-of-use emissions arising from H2D. In all cases CO 2 emissions decrease linearly with hydrogen addition by energy share, due to the reduction in the amount of carbon-containing fuel.…”

“…Many studies only considered very small hydrogen energy shares. 48,[54][55][56][57] The observed variation in NO x emissions from hydrogen addition compared to pure diesel combustion were small, and there was oen no clear trend. Other studies have showed that the trend in change in NO x emissions was only apparent for higher hydrogen fractions.…”

“…Multiple studies in Table 1 show that it is possible to configure operating conditions to retain or improve combustion performance and efficiency on hydrogen blending. 46–51…”

Comparative performance of coke oven gas, hydrogen and methane in a spark ignition engine

“…Hydrogen and methane fuel gases have received much attention over the last few decades due to their suitable characteristics as fuel gases in ICE. Many investigations have been conducted to study the influence of the composition of H2 and CH4 mixtures on various types of ICE: spark ignition (SI) [8][9][10][11][12][13][14][15], compression ignition (CI) [4,[16][17][18][19] and homogeneous charge compression ignition (HCCI) [20][21][22], as well as of different configurations of fuel injection systems and experimental conditions. Hydrogen, which is being promoted worldwide as an energy vector, offers clean combustion in terms of zero emissions of CO2, CO, and hydrocarbons (HCs) [23][24][25][26].…”