Is higher BSFC better?
A lower BSFC value is MORE efficient. Higher BSFC numbers are LESS efficient.
What does BSFC mean?
4.2 Brake specific fuel consumption. BSFC is a measure of the fuel efficiency of any engine that burns fuel and produces rotational power output.
Why does BSFC decrease with engine speed?
The decrease in BSFC is due to the better physical and chemical properties of fuel which assisted in improving combustion at low engine speeds. On the other hand, at high speeds, the friction heat losses occur and combustion deteriorates which increases the BSFC.
At what value of air fuel ratio the BSFC will be minimum?
It is easy to perceive from the figure that there is an optimum minimum value of BSFC occurred within a range of AFR from 38.144 (φ =0.9) to 49.0428 (φ =0.7) for the selected range of speed. At very lean conditions, higher fuel consumption can be noticed.
Why does brake thermal efficiency increase with load?
1.1 Brake thermal efficiency. The BTE increases as the BMEP increases because of the higher burning rates of natural gas. At lower load conditions the decrease in the air to fuel decreases the BTE.
How is BSFC calculated in diesel engine?
Pen and Paper Method
- Formula To Estimate Maximum Engine Fuel Consumption. Gallon Per Hour (GPH) = (specific fuel consumption x HP)/Fuel Specific Weight.
- 300-hp Diesel Engine Example. GPH = (0.4 x 300)/ 7.2 = 105/7.2 = 16.6 GPH.
- 300-hp Gasoline Engine Example.
- Other Related Resources:
How BSFC is related with engine load?
The BSFC was found to decrease with increase in load for all tested fuels. This is due to the higher percentage increase in brake power with load as compared to the increase in fuel consumption. From the graph, it can be noticed that the BSFC were the lowest at 40% of load.
Does RPM affect volumetric efficiency?
The volumetric efficiency increases with increases of engine at certain limit then decreases. For equivalences ratio until below 0.6, the maximum ηv was recorded at 4200 rpm. For equivalence ratio below 0.6, the maximum ηv was recorded at 3800 rpm.
How does air fuel ratio affect engine performance?
An excessively high air–fuel ratio may produce high pumping loss, high peak cylinder pressure, and high compressor outlet temperature. An excessively low air–fuel ratio may produce the problems of deteriorated combustion efficiency, high smoke, and high exhaust gas temperature.
How do you increase brake thermal efficiency?
compression ratio significantly improves the brake thermal efficiency. heat further improves the brake thermal efficiency. But, increasing cut-off ratio resulted with lower brake thermal efficiency.
Is SFC and TSFC same?
Engineers use an efficiency factor, called thrust specific fuel consumption, to characterize an engine’s fuel efficiency. “Thrust specific fuel consumption” is quite a mouthful, so engineers usually just call it the engine’s TSFC.
How do I find BSFC?
The formula of the brake specific fuel consumption is given by, BSFC = Fuel consumption rate(. m)Brake power (B.P.) Fuel consumption rate ( m . )
What is the difference between BSFC and brake?
In automotive applications, BSFC is used to evaluate the efficiency of the internal combustion engines (ICE). The keyword “brake” is related to the use of a dynamometer (electrical brake) to measure the engine parameters (fuel mass flow rate, torque, etc.).
What is the BSFC of a diesel engine?
In the case of a production gasoline engine, the most efficient BSFC is approximately 225 g/ (kW⋅h), which is equivalent to a thermodynamic efficiency of 36%. An iso-BSFC map (fuel island plot) of a diesel engine is shown.
How does the BSFC map work?
The excess torque (150 Nm) will be compensated by the electric machine (-150 Nm) which will run in generator mode and produce electrical energy. In vehicle with automatic transmissions, the BSFC map is used as a reference to calculate the shift lines for best fuel efficiency.
Is 197 g/kWh a good BSFC?
However, nobody drives at full load under normal circumstances. It can be seen that the minimum BSFC of 197 g/kWh occurs at around 1750 RPM and just shy of the full-load curve. However, a steady cruise, say in 5th gear at that RPM, would be far, far less for a correspondingly higher (worse) BSFC.