A Study on Water-Induced Damage Severity on Diesel Engine Injection System Using Emulsified Diesel Fuels

Abstract

Diesel engine emissions contribute nearly 30% of greenhouse effects and diverse health and environmental problems. Amidst these problems, it is estimated that there will be a 75% increase in energy demand for transportation by 2040, of which diesel fuel constitutes a major source of energy for transportation. Being a major source of air pollution, efforts are currently being made to curb the pollution spread. The use of water-in-diesel (W/D)-emulsified fuels comes as a readily available (and cost-effective) option with other benefits including engine thermal efficiency, reduced costs, and NOx reduction; nonetheless, the inherent effects—power loss, component wear, corrosion, etc. still pose strong concerns. This study investigates the behavior and damage severity of a common rail (CR) diesel fuel injection system using exploratory and statistical methods under different W/D emulsion conditions and engine speeds. Results reveal that the effect of W/D emulsion fuels on engine operating conditions are reflected in the CR, which provides a reliable avenue for condition monitoring. Also, the effect of W/D emulsion on injection system components-piston, nozzle needle, and ball seat–are presented alongside related discussions.

A Wavelet-Based Diagnostic Framework for CRD Engine Injection Systems under Emulsified Fuel Conditions

“…In addition, a higher brake-specific fuel consumption (BSFC) (accompanied with a reduction in exhaust gas temperature) was observed at all rotation speeds [19]. Other studies [20,21] also validate the benefits associated with diesel emulsification, yet the high oxidation potential of water on metal components means that W/D emulsion adoption still poses strong concerns [22].…”

“…Primarily, the major goal of the test was to understand the CR characteristics at varying W/D emulsion compositions at varying engine speeds and more in-depth results/analyses found in [21]. Overall, the investigation results revealed that as the water composition is increased in the different W/D emulsions, exhaust temperature is reduced at lower engine speeds and the viscosity increased proportionally, and this induced some wear (as a result of oxidation) on the critical FIS components-injector valve ball seats, injector nozzle needles, and injector valve pistons.…”

“…Although all hopes seem high when only the benefits are considered, the inherent wear/oxidation (long-term) effects from diesel emulsification may impede on-going plans (if any exist) for global adoption. Contrary to diesel emulsification, engine downsizing also seems like a promising solution; nonetheless, achieving a globally acceptable engine design on which costs, environmental concerns, wear issues, etc., are well addressed seems impossible since the realization of one may imply forfeiting the other(s) [21].…”

“…Ideally, the smooth reciprocating movement of the plunger in a fuel injector of a CRD engine relies on little/no friction between the plunger and the valve, which under realistic conditions is ensured by the lubricating effect and low viscosity of diesel. Unfortunately, W/D emulsions increase the viscosity values of the fuel which results in higher friction between reciprocating components in the injector [21]. In addition, the water molecules induce oxidation of the metal components which further results in corrosion, increased friction, and inevitably, component wear.…”

Renewability and Robustness Analysis and Review for Sustainable-Technology Propulsion Systems in Modern Transportation Infrastructure Administration

“…A study aimed to evaluate the injector performance for W/D (Water-in-Diesel) emulsified fuels at the SU KWANG Precision Co. Korea testbench, investigating the long-term degradation of such components. W/D blends, despite being a cost-effective solution in providing a renewable option for ICEs, show poor lubrication, which led to the degradation of internal fuel delivery control mechanisms for all injectors [54,55]. The typical structure of an injector is shown below in Figure 11.…”