Pump basic parameters introduced

The main performance of the basic parameters are the following: First, the flow rate Q is the amount of liquid pump delivery (volume or quality) within a unit of time. Volume flow Q said, the unit is: m3 / s, m3 / h, l / s and so on. Mass flow Qm said, the unit is: t / h, kg / s and so on. The relationship between mass flow and volume flow is: Qm = ρQ where ρ is the density of the liquid (kg / m3, t / m3) and ρ = 1000 kg / m3 at room temperature. Second, the lift H is the pump head pumping unit weight of liquid from the pump inlet (pump inlet flange) to the pump outlet (pump outlet flange) the value of energy. Which is the effective energy of a Newtonian liquid through the pump. The unit is N · m / N = m, which is pumping liquid pumping column height, used to refer to as rice. Third, the speed n speed is the shaft number of revolutions per unit time, with the symbol n that unit is r / min. Fourth, NPSH NPSH NPSH, also known as net positive nozzle, is the main parameter of cavitation performance. Naphthenic margin used domestic Δh said. Fifth, the power and efficiency Pump power is usually refers to the input power, that is, the prime mover axle power transmission axis, it is also known as shaft power, with P said; pump the effective power, also known as output power, said Pe. It is the unit of time delivered from the pump liquid in the pump to obtain effective energy. Since the head is the unit of fluid that the pump outputs, it is the effective energy obtained from the pump so that the product of the head and the mass flow and the acceleration of gravity is the effective energy obtained from the liquid output from the pump per unit of time - the pump The effective power of the pump: Pe = ρgQH (W) = γQH (W) where ρ - pumping liquid density (kg / m3); γ - heavy pumping liquid (N / m3) Flow rate (m3 / s); H - pump head (m); g - acceleration of gravity (m / s2). The difference between the shaft power P and the effective power Pe is the loss power in the pump, which is measured by the efficiency of the pump. Pump efficiency for the effective power and shaft power ratio, expressed with η.