Search results
Results from the WOW.Com Content Network
Specific Pump Power (SPP) is a metric in fluid dynamics that quantifies the energy-efficiency of pump systems. It is a measure of the electric power that is needed to operate a pump (or collection of pumps), relative to the volume flow rate. It is not constant for a given pump, but changes with both flow rate and pump pressure.
Power is more commonly expressed as kilowatts (10 3 W, kW) or horsepower (1 hp = 0.746 kW). The value for the pump efficiency, η p u m p {\displaystyle \eta _{pump}} , may be stated for the pump itself or as a combined efficiency of the pump and motor system.
With the help of these equations the head developed by a pump and the head utilised by a turbine can be easily determined. As the name suggests these equations were formulated by Leonhard Euler in the eighteenth century. [1] These equations can be derived from the moment of momentum equation when applied for a pump or a turbine.
The affinity laws (also known as the "Fan Laws" or "Pump Laws") for pumps/fans are used in hydraulics, hydronics and/or HVAC to express the relationship between variables involved in pump or fan performance (such as head, volumetric flow rate, shaft speed) and power. They apply to pumps, fans, and hydraulic turbines. In these rotary implements ...
Specific speed N s, is used to characterize turbomachinery speed. [1] Common commercial and industrial practices use dimensioned versions which are of equal utility. Specific speed is most commonly used in pump applications to define the suction specific speed —a quasi non-dimensional number that categorizes pump impellers as to their type and proportions.
A typical turbocharged V8 diesel engine might have an engine power of 250 kW (340 hp) and a mass of 380 kg (840 lb), [1] giving it a power-to-weight ratio of 0.65 kW/kg (0.40 hp/lb). Examples of high power-to-weight ratios can often be found in turbines. This is because of their ability to operate at very high speeds.
Pumps come in diameters from 90 mm (3.5 inches) to 254 mm (10 inches) and vary between 1 metre (3 ft) and 8.7 metres (29 ft) in length. The motor used to drive the pump is typically a three-phase, squirrel cage induction motor, with a nameplate power rating in the range 7.5 kW to 560 kW (at 60 Hz). [3]
Power in mechanical systems is the combination of forces and movement. In particular, power is the product of a force on an object and the object's velocity, or the product of a torque on a shaft and the shaft's angular velocity. Mechanical power is also described as the time derivative of work.