What is the relationship between the power head flow rate of a pump?

Current = Head x Flow.

The head is determined by the energy loss of water by pipes and valves, that is, the energy value that the pump can give to the water. The motor speed decreases and the head also decreases when the centrifugal pump.

After the outlet valve is closed, because the head is unchanged, the flow rate is reduced, then the current of the pump decreases, if it is fully closed, the current is the smallest, but slightly greater than the idling, because the water has resistance.

When the design (pump selection) is determined, if the actual operating head of the pump is too high, it will not only cause the efficiency of the pump to be reduced, but also seriously affect the actual flow rate of the pump.

On the contrary, if the head of the pump is too high, and the actual operating head is too low, it will also affect the efficiency of the pump and cause the flow rate to be too large during actual operation, and it is likely to increase the power of the pump and exceed the rated current of the motor.

And fever. <>

The marked power of the pump is different in practical use, the power is large when the flow is large, the power is small when the flow is small, and the head directly determines the flow, the high head is small, and the power is also small. This view is the biggest subversion of the public's preconceived notions. I have a self-priming water pump, the actual operation of the power consumption is very illustrative of this, it stands to reason that the electricity per hour, but I use the meter to record it, the result is only the hour of electricity, no wonder people say that the real power consumption of the pump is not so much, for example, it is only 750W, this I really believe.

The rated power of the pump does not need to reach its normal flow rate to reach this value, or it is a false standard, industry inertia. My pump is pumped at home, the water source is two or three hundred meters away from a shallow river, because the distance is too long, the flow is not very large, basically only rated 1 3 bar, I don't know whether the low flow rate causes the power consumption to decrease, or the actual power of the pump is not as big as the mark, still in the exploration.

From 8:47 to 9:49, it is exactly 1 hour and 2 minutes, the actual power consumption is degrees, and the actual power difference is about 60%.

In the case of a certain power, the kinetic energy theorem knows that p=f*v, i.e., w=f*s

In the use of water pumps, it is said that the work done by the pump per unit time = the gravity of the water flow * the displacement of the water volume.

It can be seen that: 1. When the power is constant, the head is inversely proportional to the flow.

2. The greater the power, the greater the product of head and flow.

Therefore, when the flow rate is the smallest, the head of the pump is the largest; When the head is the smallest, the flow rate is maximum.

Landlord. Your formula is your own development, flow.

The head is basically inversely proportional, but it should be taken into account here.

Consumption of power.

Probably yes.

Water pump power = water power.

and the power consumed by the pump itself. The efficiency of each type of pump will be different according to the different impellers, the efficiency of the pump = water power Total output power.

I think you calculate that.

There is no scientific basis for this.

Power and flow.

Head. It is not directly related, everything depends on the performance of the impeller! If in.

When the impeller is fixed, the more power it will have.

Then the lower his efficiency.

n= qh 1000 ,- the gravity of the liquid, the ox cubic meter;

Efficiency; n-power, kw;

h-head, m;

Q-Volume flow rate, cubic meters per second.

Shaft power = flow rate head medium specific gravity 3600 pump efficiency.

Flow unit: cubic hour, head unit: meter.

p=, where h is the head, the unit m, q is the flow, the unit is m3 h, is the efficiency of the pump. p is the shaft power, in kw

That is, the shaft power of the pump p= gqh 1000 (kw), where =1000kg m3, g=

The unit of specific gravity is kg m3, the unit of flow is m3 h, the unit of head is m, 1kg = Newton.

The pump with a large flow rate is used in a small flow rate, which will bring a decrease in speed, that is, a very low speed can meet the operation, and the pump is generally required to run at a speed of more than 20Hz, because the pump motor needs to dissipate heat, and the speed is too small, the heat dissipation capacity of the fan of the motor will be very small, which is easy to cause the heat dissipation of the motor to be reduced and the motor to burn out.

The head and flow rate of the pump are inversely proportional, that is, when the flow rate increases, the bend will decrease; When the flow rate decreases, the head increases. This is because the pump needs to overcome the resistance and gravity of the water while transporting the water flow, and the resistance and gravity are related to the speed and flow of the water flow, so there is an inverse proportional relationship between the head and the wild sun flow. This is why when choosing a pump, it is necessary to match the pump according to the flow rate and head of the need.

Shaft power = flow head medium specific gravity 3600 pump efficiency flow unit: cubic hour, head unit: m p = , r where h is the head, unit m, q is the flow, the unit is m3 h, is the efficiency of the pump.

p is the shaft power, in kwThat is, the shaft power of the pump p= gqh 1000 (kw), where =1000kg m3, g = the unit of specific gravity is kg m3, the unit of flow is m3 h, the unit of head is m, 1kg = Newton large flow pump is used in small flow, which will bring the situation of reduced speed, that is, a very low speed can meet the operation, the pump is generally required to run at a speed of more than 20hz, because the pump motor needs to dissipate heat, the speed is too small, the heat dissipation capacity of the fan of the motor will be very small, It is easy to reduce the heat dissipation of the motor and burn the motor.

There is a close relationship between the head of the pump and the flow rate, and the data on the nameplate is usually made in the laboratory. It is to input a rated shaft power to the pump, and the flow rate measured at the rated speed and head is measured. The relationship between head and flow is that in the case of a certain speed, the higher the head, the smaller the flow, and the lower the head, the greater the flow.

However, in the actual application of water pumps, it is normal that the rated flow rate will be less than the actual flow rate. Because in practical applications, there are many factors that will restrict this traffic. Example:

The actual lift will be higher than the rated lift (the head of the pump = suction head + drainage head), the diameter of the drainage pipe is too thin or too much elbow causes too much drainage resistance, the check valve (faucet) of the pump is blocked by debris, when the pulley is used, the rated speed of the pump can not be reached, the inlet pipe leaks, and so on can cause the flow rate to be reduced. Therefore, when choosing a water pump, it is necessary to increase the value of the budget by one level, and leave a certain margin.

Secondly, it is your water inlet pipe, when the water pump is above the water surface, whether the water inlet pipe is above the pool or below, the result is the same, and it will not affect the flow rate of the water pump.

The relationship between the power of the pump and the head and the flow rate, including the detailed unit, I hope to be detailed, thank you.

The relationship between the power of the pump and the head and the flow rate, including the detailed unit, I hope to be detailed, thank you for your kindness, <>

Regarding the relationship between pump power, head and flow, we generally buy any filter pump, which will involve 3 parameters: power, head, flow head is the height of the pump, the unit is meters, the flow rate can be obtained according to its unit l h, and the flow rate is the amount of water absorbed by the pump per hour. The greater the power, the greater the head and flow, and the power of the pump is fixed, so the actual head of the pump can be expressed in the following formula:

h=hx-sxq42--(1)(a2 means squared) where: h--the actual first leg of the pump, calculated according to the position of the disadvantage search you place the pump: hx-the head generated by the pump in q=0, which is also the theoretical head, which is generally related to power; sx - the internal friction of the water pump; Q - the flow rate of the pump is obtained by (1) formula q=y[(hx-h) sx] 2) (represents the root number) for a given pump, hx and sx are constant, from (2) equation, when the pump head h decreases in actual operation, the pump flow rate increases, your pump may have an actual head much less than the rated head, so the flow rate increases a lot, which can explain why most pumps can not reach the rated flow rate of the pump body, because the actual head determines the flow rate.

The flow rate of the pump with the same power depends on the actual lifting height (head) of the pump, and I hope it can help you know it. <>

How to calculate pump power, flow rate and head.

Hello, for you to find the following information, because I am not a professional, please refer to the specific information: there is a certain relationship between the power, flow and head of the pump, which can be calculated by the following formula: power (p) = flow rate (q) head (h) fluid density ( ) gravitational acceleration (g) where fluid density ( ) and gravitational acceleration (g) are constants.

Flow (q) = Power (p) (or Acceptance Head (H) Fluid Density ( ) Gravitational Acceleration (g)) Head (H) = Power (p) (Flow (q) Fluid Density ( ) Gravitational Acceleration (g)) These formulas can be used to calculate the power, flow and head of a water pump, but there are a few things to keep in mind: When using these formulas, make sure you use the same units. For example, power can be expressed in watts (W), flow can be expressed in cubic meters per second (m s), and head can be expressed in meters (m).

Fluid density refers to the density of a fluid, usually expressed in kilograms per cubic meter (kg m). The fluid density may vary for different liquids, so it should be replaced according to the coarse accommodation value of the specific liquid. The acceleration due to gravity (g) is usually taken as m s.

Note that these formulas are based on calculations under ideal conditions and ignore the efficiency of the pump itself and the losses in the system. In practical applications, factors such as pump efficiency, pipe friction loss, elbow resistance, etc., also need to be considered to obtain more accurate results. In order to ensure accuracy and safety, it is recommended to seek the help and guidance of professional engineers in the actual engineering design and application.