Internal-Combustion Engines

The availability and economics of the power source frequently dictate that internal-combustion engines be selected to drive pumping units. Technical Data used in the field explained in petroleum courses in Rawalpindi. For the sake of brevity. internal-combustion engines arc simply called “engines” throughout this chapter. Basically, engines used on pumping units are divided into two speed classifications: slowspeed engines and high-speed engines.

Slow-speed engines are those with one or two cylinders, which generally have a maximum crankshaft speed of 750 revimin or less. High-speed engines are multicylinder (usually four or six cylinders) and have an average speed of more than 750 but not more than 2.000 revitnin.

Generally. high-speed engines have less torque than comparable horsepower, slow-speed engines. Therefore. high-speed engines will experience greater speed variation on the cyclic load of a pumping unit. Considerable speed variation at the prime mover has many benefits on various components of a sucker-rod-beam-type pumping unit system. 5.b While governors tend to limit speed variation. it will not be eliminated. Speed variations of up to 35%, with resulting reductions in cyclic loads. Have been measured on high-speed engine-driven pumping units. Some more details of petroleum courses in rawalpindi are as under.

Two-stroke cycle engines or two-cycle engines complete their work in only two strokes of the piston, which is accomplished with one revolution of the crankshaft. The two strokes are compression and power. The process of filling the cylinder with a fresh charge and exhausting the burned gases occurs almost simultaneously near the end of the power stroke. The horizontal sliding piston first uncovers exhaust ports and then uncovers intake ports, which charges the cylinder and thereby flushes out the exhaust gases. Because some of the fuel is lost at this point, two-cycle engines, above about 40 hp, are equipped with fuel injection systems that raise their fuel efficiency close to that of a four-cycle engine. Normally. a two-cycle  engine. for a given displacement and speed. develops 1.6 times the power of an equivalent four-cycle engine. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join oil field after petroleum courses in Islamabad.