Search results
Results from the WOW.Com Content Network
One GGE of natural gas is 126.67 cubic feet (3.587 m 3) at standard conditions. This volume of natural gas has the same energy content as one US gallon of gasoline (based on lower heating values: 900 BTU/cu ft (9.3 kWh/m 3) of natural gas and 114,000 BTU/US gal (8.8 kWh/L) for gasoline). [22]
Absolute cylinder pressure is used to calculate the dynamic compression ratio, using the following formula: = where is a polytropic value for the ratio of specific heats for the combustion gases at the temperatures present (this compensates for the temperature rise caused by compression, as well as heat lost to the cylinder)
In 1994 the U.S. National Institute of Standards and Technology (NIST) introduced gasoline gallon equivalent (GGE) as a metric for fuel economy for natural gas vehicles. NIST defined a gasoline gallon equivalent (GGE) as 5.660 pounds of natural gas, and gasoline liter equivalent (GLE) as 0.678 kilograms of natural gas. [18]
Methane, the main component of natural gas, has an autoignition temperature of 580 °C, [48] whereas gasoline and diesel autoignite at approximately 250 °C and 210 °C respectively. With a compressed natural gas (CNG) engine, the mixing of the fuel and the air is more effective since gases typically mix well in a short period of time.
Compressed natural gas (CNG) is a fuel gas mainly composed of methane (CH 4), compressed to less than 1% of the volume it occupies at standard atmospheric pressure.It is stored and distributed in hard containers at a pressure of 20–25 megapascals (2,900–3,600 psi; 200–250 bar), usually in cylindrical or spherical shapes.
The Cummins L10 also has a sister engine which runs on compressed natural gas (CNG). [2] The engine was introduced in 1992 as the L10G before being replaced by the L Gas Plus in 2001 until it became the ISL G in collaboration with Westport Innovations in 2008, now based on the C-series engine architecture. The ISL engines were manufactured at ...
Gas engines that run on natural gas typically have a thermal efficiency between 35-45% (LHV basis)., [12] As of year 2018, the best engines can achieve a thermal efficiency up to 50% (LHV basis). [13] These gas engines are usually medium-speed engines Bergen Engines Fuel energy arises at the output shaft, the remainder appears as waste heat. [8]
The Pratt & Whitney TF30 used on the F-111 had a pressure ratio of about 20:1, while newer engines like the General Electric F110 and Pratt & Whitney F135 have improved this to about 30:1. An additional concern is weight. A higher compression ratio implies a heavier engine, which in turn costs fuel to carry around.