Identification of the Problem in Controlling the Air–Fuel Mixture Ratio (Lambda Coefficient λ) in Small Spark-Ignition Engines for Positive Pressure Ventilators

Łukasz Warguła; Piotr Kaczmarzyk; Bartosz Wieczorek; Łukasz Gierz; Daniel Małozięć; Tomasz Góral; Boris Kostov; Grigor Stambolov

doi:10.3390/en17174241

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Title

Identification of the Problem in Controlling the Air–Fuel Mixture Ratio (Lambda Coefficient λ) in Small Spark-Ignition Engines for Positive Pressure Ventilators

Authors

Łukasz Warguła (WIM) ^{[ 1 ][ 2.9 ][ P ]}
Piotr Kaczmarzyk (WIM) ^{[ 2 ][ 2.9 ][ SzD ]}
Bartosz Wieczorek (WIM) ^{[ 1 ][ 2.9 ][ P ]}
Łukasz Gierz (WIM) ^{[ 1 ][ 2.9 ][ P ]}
Daniel Małozięć
Tomasz Góral
Boris Kostov
Grigor Stambolov

^{[ 1 ]} Instytut Konstrukcji Maszyn, Wydział Inżynierii Mechanicznej, Politechnika Poznańska | ^{[ 2 ]} Wydział Inżynierii Mechanicznej, Politechnika Poznańska | ^{[ P ]} employee | ^{[ SzD ]} doctoral school student

Scientific discipline (Law 2.0)

[2.9] Mechanical engineering

Year of publication

2024

Published in

Energies

Journal year: 2024 | Journal volume: vol. 17 | Journal number: iss. 17

Article type

scientific article

Publication language

english

Keywords

EN

PPV
fuel supply system control
incorrect operation of a combustion engine
lean fuel–air mixture
fire brigade equipment
smoke removal from buildings

Abstract

EN The air–fuel ratio is a crucial parameter in internal combustion engines that affects optimal engine performance, emissions, fuel efficiency, engine durability, power, and efficiency. Positive pressure ventilators (PPVs) create specific operating conditions for drive units, characterized by a reduced ambient pressure compared to standard atmospheric pressure, which is used to control carburetor-based fuel supply systems. The impact of these conditions was investigated for four commonly used PPVs (with internal combustion engines) in fire services across the European Union (EU), using a lambda (λ), carbon dioxide (CO2), carbon monoxide (CO), and hydrogen carbon (HC) analyser for exhaust gases. All four ventilators were found to operate with lean and very lean mixtures, with their lambda coefficients ranging from 1.6 to 2.2. The conducted tests of the CO2, CO, and HC concentrations in the exhaust gases of all four fans show dependencies consistent with theoretical analyses of the impact of the fuel–air mixture on emissions. It can be observed that as the amount of burned air decreases, the values of CO and HC decrease, while the concentration of CO2 increases with the increase in engine load. Such an operation can accelerate engine wear, increase the emission of harmful exhaust gases, and reduce the effective performance of the device. This condition is attributed to an inadequate design process, where drive units are typically designed to operate within atmospheric pressure conditions, as is common for these engines. However, when operating with a PPV, the fan’s rotor induces significant air movement, leading to a reduction in ambient pressure on the intake side where the engine is located, thereby disrupting its proper operation.

Date of online publication

25.08.2024

Pages (from - to)

4241-1 - 4241-15

DOI

10.3390/en17174241

URL

https://www.mdpi.com/1996-1073/17/17/4241

Comments

Article Number: 4241

License type

CC BY (attribution alone)