Auxiliary power
Auxiliary Power Unit: An auxiliary power unit or the APU is a small, compact self-contained generator used to provide power to grounded aircrafts. It supplies the power to start the jet engines, compressed air, and electricity to maintain the hydraulic pressure and running the air conditioning. In many aircrafts, these units can provide electrical power in the air instead of the main power source. As these power units are fitted to some tanks they reduce the consumption of fuel consumption which would be required for running the main engine. These Auxiliary power units help in cutting the harmful emissions and noise and therefore good for the environment. They also save the cost of the fuel and reduce the expenditure for maintenance.
Auxiliary Power Units for Truck: Truck Auxiliary power units are the primary source of onboard electrical power for the vehicle. These portable systems are preferred as they can provide power for heat, air conditioning for trucks without idling. It therefore saves the amount of fuel used to be burnt in truck idling. These auxiliary power units for trucks consist of an internal combustion diesel engine and generator with heat recovery system to provide electricity and heat. These compact units can produce heat for both the sleeper cabin of the truck and the engine. They are capable of running the air-conditioning and most of the lighting appliances. But these can not provide power to television or microwave. Fully integrated power units consist of a compressor, an alternator, and an inverter or charger along with the engine. The inverter or charger provides electric power to the vehicle driving area as well as the sleeping cabin at the back. The APU is able of providing power to a 40-foot bus to perform efficiently in local stop-and-go driving. A high energy battery pack, or a bigger engine can be used comfortably for heavy vehicles such as refuse trucks, or applications requiring extended high speed driving.
Auxiliary Power Supply: Auxiliary power supply may be used to provide backup resources in a crisis or when regular power supply fails. They may include lighting, generators and other apparatus and find uses in a wide variety of settings from residential homes to hospitals, scientific laboratories and modern naval ships or aircrafts. There are many manufacturers who produce auxiliary power supply units which are compact, light weight, low on noise and emission and high in performance. These are directly fed from high voltage input catenaries or third rail system to provide power for specific loads, such as air conditioners, heaters, lighting and propulsion blowers.
Auxiliary Power APUS: The APU is powered by a small gas turbine engine that provides compressed air from within or drives an air compressor. Though these were first used on the Pemberton-Billing P.B.31 Night Hawk Scout aircraft in 1916, now we can find them with most of the commercial aircrafts. The Boeing 727 in 1963 used one such power unit which allowed it to operate at smaller, regional airports, where the ground power supply resources may have been limited. A typical APU for commercial transport aircraft has three main sections: The Power section, Load compressor and Gearbox. The power section consists of the gas generator part of the engine and produces all the power. The load compressor is a shaft-mounted compressor for providing all pneumatic power for the aircraft. Inlet guide vanes regulate airflow to the load compressor and the surge control valve maintains stable or surge-free operation of the turbo machine. The gearbox consisting of complex mechanical gears transfers the power from the main shaft of the engine to an oil-cooled generator for generating electrical power. Power is also transferred to other units like the fuel control, lube module, and cooling fan from the gearbox. A starter motor connected through the gear train starts the function of the APU. RigMaster is the only stand-alone self-contained auxiliary power unit on the market.