Effect of Gaseous Fuels and Coolant Temperature on Performance and Combustion Characteristics of a Low-Speed Single Cylinder Diesel Engine
Journal Title: Journal of Agricultural Machinery - Year 2022, Vol 12, Issue 3
Abstract
IntroductionToday, diesel engines provide the main power source for the world equipment e.g., common propulsion generators in industry and agriculture. These engines are widely used due to their high combustion efficiency, reliability, compatibility, and cost-effectiveness. However, diesel engines are one of the most critical consumers of fuel which in turn causes some environmental pollution. One of the convenient and low-cost ways to reduce the pollution of these engines is dual-fuel mode and the use of gaseous fuels as an alternative fuel. This study investigated the effect of blending CNG and LPG with neat diesel in dual-fuel mode. Besides, the variation in engine coolant temperature on engine performance characteristics was experimentally studied.Materials and MethodsThe experimental apparatus consisted of a stationary, four-stroke, naturally aspirated, water-cooled, single-cylinder compression ignition engine. To control the engine load, an electrical dynamometer was made using a 7.5 kW three-phase generator and coupled to the engine as a cradle. A load cell was used to determine the force applied to the generator. The engine speed was monitored continuously by a tachometer. Fuel consumption was measured by using a weight method. A thermostat with variable temperature was used to control the temperature of the engine coolant. To measure the mass flow of air entering the cylinder, an airbox with a sharp edge orifice was used. For this study, factorial experiments in the form of a randomized complete block design with three replications were utilized to analyze the data statistically. The studied parameters were three levels of fuel ratio (100% diesel, 20% diesel and 80%± 2% CNG, 20% diesel and 80%±2% LPG), 11 engine speeds (1500 to 1600 rpm with 10 rpm intervals), and three engine coolant temperatures (50, 60, and 70 °C). All experiments were conducted in the governor control mode.Results and DiscussionThe results showed that the torque, brake power and brake mean effective pressure (BMEP) in the diesel-CNG mode at all engine speeds and in the diesel-LPG mode at low engine speeds significantly increased compared to pure diesel. The increases in these parameters in the diesel-CNG mode were 18.67%, 19.56% and 19.85%, and in the diesel-LPG mode were 14.02%, 13.86% and 14.2%, compared to those related to the pure diesel, respectively. This increase could be due to the high calorific value of gas fuels and improvement of combustion inside the cylinder due to the formation of homogeneous charge. At low engine speeds, the reductions in the brake specific fuel consumption (BSFC) and brake specific energy consumption (BSEC) for coolant temperature 60 °C were 11.21% and 10.77%, compared to coolant temperature 50 °C, respectively. Also, the BSFC and BSEC for diesel-CNG dual-fuel mode decreased by 8.12% and 10.81%, respectively. These values for the diesel-LPG dual-fuel mode were 5.4% and 2.4%, respectively. The brake thermal efficiency (BTE) also showed a significant increase at high speeds and when using the dual-fuel operational mode. However, raising the coolant temperature due to reducing the heat losses of the engine increased the BTE. The increases in BTE for coolant temperatures 60 and 70 °C were 7.19% and 4.37%, compared to the coolant temperature of 50 °C, respectively. When using the engine in dual-fuel mode, the volumetric efficiency due to reducing the air ratio showed a significant reduction. These diesel-CNG and diesel-LPG dual-fuel mode values were 20.31% and 24%, respectively. Furthermore, raising the coolant temperature diminished the volumetric efficiency. The reduction in volumetric efficiency for the coolant temperatures of 60 °C and 70 °C were 6.84% and 19.91% compared to the coolant temperature of 50 °C, respectively.ConclusionThe following conclusions can be deduced based on this study:The use of gaseous fuels as the main fuel and with a small amount of diesel in compression ignition engines is possible and improves the engine's performance characteristics.In the diesel-CNG mode, torque, brake power and BMEP at all engine speeds and in the diesel-LPG mode at low engine speeds significantly increased compared to pure diesel because of improved combustion inside the cylinder.At low engine speeds, increasing the coolant temperature reduced the BSFC and BSEC. Also, in the dual-fuel mode compared to the engine with baseline diesel fuel, the BSFC and BSEC were significantly lower due to the higher calorific value of gaseous fuels and higher power generation.The BTE at high engine speeds and when the engine was in dual-fuel mode showed a significant increase. Also, increasing the coolant temperature due to reducing the heat losses of the engine increased the BTE.When using the engine in the dual-fuel mode, due to the volume of air replaced by the gas, the volumetric efficiency showed a significant reduction. Also, raising the coolant temperature diminished the volumetric efficiency.Overall, it can be stated that the use of a diesel-CNG dual-fuel mode with a coolant temperature of 60 °C at entire engine speeds has the best outputs on the performance and combustion characteristics of the engine.
Authors and Affiliations
B. Sabahi,H. Bahrami,M. J. Sheikhdavoodi,S. M. Safieddin Ardebili,E. Houshyar,
Keywords
Related Articles
- EP ID EP718047
- DOI https://doi.org/10.22067/jam.2021.68089.1007
- Views 54
- Downloads 0
Micromechanical Behavior of Potato Tissue by Scanning Electron Microscopy: Effect of Storage Time, Impact Energy and Curvature Radius of Impact Location
Introduction The mechanical impacts occur mainly during harvesting and post-harvesting operations, lead to the breaking of cell membranes in cellular structure that dependS on impact intensity. Furthermore, turgor pressu...
Influence of Conservation Tillage on some Soil Physical Properties and Crop Yield in Vetch-Wheat Rotation in Dryland Cold Region
Introduction Winter wheat is an important, well-adapted grain crop under dryland condition of the northwest of Iran. Soil water is the most limiting resource for crop growth in dryland areas. Therefore, farmers need to u...
Optimization and Analysis of a λ-Formed Straight Line Linkage for Design of Reversible Disk Plow.
Disk plows are one of the most important tillage tools. Two way (reversible) disk plows can perform continues plowing. So they can save time and costs and hence improve overall efficiency. In this study, a “two-way” disk...
A Data-driven Model for Predicting the Yield of Recoverable Sugar from Sugarcane
IntroductionSugarcane is a strategic agricultural product and increasing productivity and self-sufficiency in its production is of special importance. The most important product of sugarcane is sugar. Various factors lik...
Design, Fabrication and Evaluation of a Wet Cattle Manure Size Reduction Machine
Introduction The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet ma...