The performance parameters of the pump is a set of data used to characterize the performance of pumps, including flow, head, power,
efficiency, and allows the suction on the basic parameters of a high vacuum or cavitation margin, speed, etc. 6.
Pump products of Shanghai the Hutai Valve Manufacturing Co., Ltd. covers: chemical pumps, fire pumps, diaphragm pumps, sewage pumps.
Pump flow rate
Flow refers to the volume or weight of the transmission fluid in the pump unit of time. Q represents the commonly used unit is m3 / h m3
/ s, and L / s or t / h. Traffic on the pump nameplate is the pump s design flow, the Friends, said the amount of traffic.
Pump running in the flow for maximum efficiency.
Pump head
The head refers to the increase in energy units of gravity of liquid from the pump inlet to the outlet, and that the energy gained by
the unit gravity after water through the pump. H said that the units mH2O, generally referred to as m. The head on the pump nameplate is
the design of the pump head, corresponding to the head through the design flow, also known as the amount of lift.
The pump power
Power to pump the work done per unit time, unit is (KW).
1, the effective power of the pump
Effective power, also known as the output power of the pump means to pump the liquid from the pump where the energy flow per unit time.
Using Pu said.
2, shaft power
The shaft power, also known as the pump input power is the power machine to pass water pump shaft power. With P said. The shaft power on
the pump nameplate corresponds to flow through the design of shaft power, also known as the rated shaft power.
3, the supporting power
Supporting power matching for the pump power machine with power P said. Generally on the pump nameplate or sample are marked with the
value of supporting power.
Efficiency of the pump
Efficiency refers to the percentage of effective power of the pump shaft power ratio, it marks the effectiveness of the pump energy
conversion is an important technical and economic indicators of the pump and use η said. Efficiency on the pump nameplate corresponds
to the efficiency through the design flow, the efficiency of the highest efficiency of the pump. The higher the efficiency of the pump,
said the smaller the energy loss in the pump work.
The pump shaft power can not all be passed to the output of the liquid, there must be a part of energy loss. Energy losses within the
pump can be divided into three parts, the hydraulic losses, volume losses and mechanical losses.
1, the hydraulic losses and hydraulic efficiency
The water flowing through the pump suction chamber, the impeller, the room pressure friction loss, partial loss and shock losses. The
friction loss is a loss caused by the frictional resistance of water flow parts intramural. The partial loss is the loss of water caused
by the flow velocity magnitude and direction of change in the pump. The impact of the loss is the water pump run-time in non-design
conditions in the leaves at the entrance to the exit and the pressure loss of indoor. Hydraulic loss is greater the smaller the pump
head. Not take into account the hydraulic losses within the pump head of the theoretical head HT, the pump head H and theoretical head H
and theoretical head HT of the ratio, called the hydraulic efficiency ηh.
2, volume loss and volumetric efficiency
After the water flow to the impeller, a small portion of high-pressure water pump body clearance (such as less leakage ring) and the
axial force balance device (such as balance holes) leaked to the import of the impeller, another part of the leakage from the seal
device to the pump in vitro consumed part of the energy, ie, volume loss. Leakage q Q the smaller the greater the pump the water out.
The flow rate Q of the pump exports and imports flow through the pump Q + q s is called the volumetric efficiency ηV.
3, the mechanical losses and mechanical efficiency
When the impeller is rotating in the liquid, before the outer surface of the rear cover and liquid friction losses (ie roulette losses),
the shaft rotation axis and shaft seal, the bearing friction loss, to overcome the friction losses consumed part of the energy, namely,
mechanical loss, mechanical loss of power Pm. Deducted from the pump input power, the power of mechanical losses, the impeller is passed
to the liquid called water power Pw said.
The efficiency of the pump is the product of the volumetric efficiency, hydraulic efficiency and mechanical efficiency. Improve the pump
efficiency, we must reduce the various types of losses within the pump. Improve the efficiency of the pump, apart from the hydraulic
model, the choice of materials, processing technology, components and other aspects to be improved and enhanced, but also pay attention
to the correct choice of pump type, to ensure the installation quality, reasonable adjustment of operating conditions and to strengthen
the maintenance and management in order to pumps often run in the state of high efficiency, to save energy, reduce costs and improve
economic efficiency.
Water absorption of the pump
Allow the suction on the vacuum height or must NPSH is the characterization of pump water absorption parameters. Energy parameters to
determine the elevation of the pump installation in the pumping station design, water absorption. Allow vacuum suction on the height Hs
said must be empty of margin (NPSH) r, in units of m.
The pump speed
Speed ​​of the shaft per minute rotation of the number of n represents the unit is r / min. The nameplate on the speed of the pump speed,
also known as the rated speed. Speed ​​is an important parameter affecting the performance of pumps, when the speed changes, the five
other performance parameters of the pump table changes accordingly.
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