What is the specific concept of a pump head?

Pumps can usually be divided into three categories: positive displacement pumps, power pumps, and other types of pumps according to their working principle. In addition to classifying by working principle, it can also be classified and named in other ways. For example, according to the drive method, it can be divided into electric pump and water wheel pump; According to the structure, it can be divided into single-stage pump and multi-stage pump; According to the use, it can be divided into boiler feed pump and metering pump, etc.; According to the nature of the conveyed liquid, it can be divided into water pump, oil pump and mud pump.

There are many types of pumps, which can be divided into the following according to the working principle: Power pump, also known as impeller pump or vane pump, relies on the dynamic action of the rotating impeller on the liquid, continuously transmits energy to the liquid, so that the kinetic energy (main) and pressure energy of the liquid increases, and then converts the kinetic energy into pressure energy through the extrusion chamber, which can be divided into centrifugal pumps, axial flow pumps, partial flow pumps and vortex pumps. Positive displacement pumps, relying on containment liquids....

Head h(m).

The head of a centrifugal pump, also known as the head of the pump, refers to the energy obtained by a single weight fluid through the pump.

The head of the pump depends on the structure of the pump (such as the diameter of the impeller, the bending of the blades, etc.), and the speed. At present, the indenter of the pump cannot be accurately calculated theoretically, and it is generally determined by experimental methods.

The head of the pump can be determined with the experiment, that is, a vacuum gauge is installed at the inlet of the pump, and a pressure gauge is installed at the outlet, if the kinetic energy difference on the cross-section of the two gauges is not counted (i.e., δu2 2g=0), and the energy loss between the cross-sections of the two gauges is not counted (i.e., f1-2=0), the head of the pump can be calculated by the following formula.

Note the following two points:

1) where P2 is the reading of the pressure gauge at the outlet of the pump (Pa); P1 is the reading of the vacuum gauge at the inlet of the pump (negative gauge pressure value, Pa).

2) Pay attention to distinguish between the two different concepts of head (pressure head) and lifting height of centrifugal pump.

Head refers to the amount of energy per unit weight of fluid that passes through the pump. In a piping system, between two sections (including the pump), the Bernoulli equation is listed and organized.

where h is the head, and the lift height refers only to δz.

Example 2-1 now measures the head of a centrifugal pump. When the working fluid is 20 clean water and the measured flow rate is 60m h, the pump inlet vacuum gauge reads and the outlet pressure gauge reads gauge pressure), and it is known that the vertical distance between the two meters is the same as the diameter of the suction pipe and the pressure out pipe of the pump, try to calculate the head of the pump.

Solution. Check 20, h=

1 MPa is equivalent to about 100 meters of water.

p outlet = m Hg = 47 m water jet.

p inlet = m Hg = 2 m water jet.

is the density of the liquid.

h = (p outlet - p inlet) = 45 m.

The head of the pump refers to the height at which the pump can lift water, which is usually expressed in h and the unit is m. The head of the centrifugal pump is based on the center line of the impeller and is composed of two parts. The vertical height from the centerline of the impeller of the pump to the water surface of the water source, that is, the height at which the pump can suck up the water, is called the suction head, referred to as the suction lift; The vertical height from the centerline of the impeller of the pump to the water surface of the outlet pool, that is, the height at which the pump can press the water up, is called the pressurized water head, referred to as the pressure range.

i.e. pump head = suction head + pressurized head It should be pointed out that the head indicated on the nameplate refers to the head that can be generated by the pump itself, and it does not include the loss head caused by the frictional resistance of the pipeline water flow. When choosing a water pump, pay attention not to be ignored. Otherwise, you won't be able to pump water.

The effective energy obtained per unit weight of liquid after it has flowed through the pump. It is an important working performance parameter of the pump, also known as the pressure head. It can be expressed as an increase in the pressure, kinetic, and potential energy heads of the fluid, ie.

h=(p2-p1) g+(c2 2-c1 2) 2g+z2-z1 where h——head, m;

P1, P2 - the pressure of the liquid at the inlet and outlet of the pump, Pa;

C1, C2 - the flow rate of the fluid at the inlet and outlet of the pump, m s;

z1, z2 - inlet and outlet height, m;

– density of liquid, kg m3;

g – acceleration due to gravity, m s2.

It is how high the water can be raised, such as 10 meters, and if it exceeds 10 meters, it will not be able to pump water.

For example, calculate the head of the submersible pump, if the depth of the well is 10 meters + the height of the pump is 10 meters (if it is a plane distance, 10 meters is converted into a vertical distance of 1 meter) = 20 meters of head.

The head is calculated from the outlet of the pump. The height from the surface of the water to the pump belongs to the suction lift.

The head does not count the distance of horizontal operation, only the distance from the vertical upward. But horizontal distances and turns also consume head, because there is resistance in the pipe!

The head of the pump has a direct relationship with the flow, the smaller the flow, the higher the head, the larger the flow, the smaller the head, and different flows correspond to different heads.

Generally speaking, the lift is how high the water can be pumped, from the water surface to the pump body for the suction stroke, from the pump body to the pumping height for the lift, the sum of the suction stroke and the head is the total head, if the suction stroke is not enough, no matter how high the lift is, it is impossible to pump the water rake. Except for submersible pumps.

The height that the pumped water can reach from the pump shaft is called the pump head.

The pump head is divided into: suction head (lower head), water discharge head (upper head), total head (actual head net head) and device head.

Suction head: It is the height from the center of the pump to the lower water surface, also known as the lower head;

Outlet head: It is the height from the center of the pump to the upper water surface, also known as the upper head;

Total head: It is the height from the lower water surface to the upper water surface, that is, the sum of the lower head and the head, also known as the actual head or net head;

Device head: It is the total head plus the resistance loss of the entire pipeline and pump system.

Head – the ability to overcome resistance. These resistances include: elevation, wall resistance of the pipe, resistance of pipe fittings, resistance of extension, resistance to movement of the medium (viscosity).

These resistances constitute the sum of the resistance transmitted by the impeller of the pump to the medium, and when this energy is consumed, the medium is not moving, and the end point of this movement is the maximum head.

Head: The head of the pump, also known as the head of the pump, refers to the energy obtained by the pump per unit weight of fluid.

Extended Materials. The head of the pump refers to the height at which the pump can lift water. It is an important working performance parameter of the pump, also known as the pressure head. It can be expressed as an increase in the pressure, kinetic, and potential energy heads of the fluid, ie.

h=(p2-p1) g+(c2 2-c1 2) 2g+z2-z1 where h——head, m;

P1, P2 - the pressure of the liquid at the inlet and outlet of the pump, Pa;

C1, C2 - the flow rate of the fluid at the inlet and outlet of the pump, m s;

z1, z2 - inlet and outlet height, m;

– density of liquid, kg m3;

g – acceleration due to gravity, m s2.

The difference between the total energy per unit of liquid at the inlet and outlet sections of the pump is the pump head. Pump head refers to the value-added energy of the unit weight of liquid pumped by the pump from the pump inlet (pump inlet flange) to the outlet (pump outlet flange). That is, the work done by the pump on a unit weight of liquid.

The pump head is represented by the letter H, and the unit of the pump head is the height of the liquid pumped in m. The pump head, also known as the pressure head of the pump, refers to the energy obtained by the single weight fluid through the pump.

The pump head changes with the change of flow, the pump head is low when the flow rate is large, and the pump head is high when the flow rate is small.

The pump head is essentially the mechanical energy value of the water flow per unit weight given by the water pump, that is, the height at which the pump can theoretically lift water. The unit is the height of the water column, and it is customary to omit the "water column" and express it in m. Because when the water flows in the pipeline, it needs to consume a part of the energy (called head loss) due to resistance and friction, so the theoretical head of the pump is equal to the sum of the actual pump head and the lost pump head.

Total head: actual head + loss head Suction head = actual suction head + water absorption loss head Outlet head = actual outlet head + water loss head.

The "head" of a pump refers to the vertical height at which the pump is able to raise the flow of water during operation. The head is usually expressed in meters (m). Among the performance parameters of the pump, the head is an important indicator, which reflects the pressure loss that the pump can overcome during the transfer of fluids.

The head usually consists of the following parts:

Static head: refers to the vertical distance between the outlet of the pump pin and the highest point of the conveyed liquid.

Moving head: refers to the pressure loss that the pump overcomes when transporting fluids, including pipeline friction loss, local loss (such as elbows, valves, etc.) and other additional pressure losses.

Total head: refers to the sum of the static head and dynamic head of the pump, which indicates the total pressure head that the pump can provide in the process of conveying fluid.

When selecting a water pump, it is necessary to select a suitable head according to the actual working conditions (including the nature of the conveyed fluid, the distance to be conveyed, the elevation of the pipeline, etc.). A head that is too large or too small can lead to poor performance, reduced efficiency or even damage to the pump.

The head of the pump refers to the height at which the pump can lift water. It is an important working performance parameter of the pump, also known as the pressure head. It can be expressed as an increase in the pressure, kinetic, and potential energy heads of a fluid.

The head of the pump is based on the center line of the impeller and is composed of two parts. The vertical height from the centerline of the impeller of the pump to the water surface of the water source, that is, the height at which the pump can suck up the water, is called the suction head, referred to as the suction lift; The vertical height from the centerline of the impeller of the pump to the water surface of the outlet pool, that is, the height at which the pump can press the water up, is called the pressurized water head, referred to as the pressure range. The low head of the pump means that the pressure of the pump is not large enough to transport water to the upper floors.

If the pump head is relatively high, it will be easier for residents to supply water.

A water pump is a machine that transports or pressurizes a liquid. It transmits the mechanical energy or other external energy of the prime mover to the liquid, so that the liquid energy increases, and is mainly used to transport liquids including water, oil, acid and alkali, emulsion, suspension emulsion and liquid metal.

It can also convey liquids, gaseous mixtures and liquids containing suspended solids. The technical parameters of pump performance include flow, suction lift, head, shaft power, water power, efficiency, etc.; According to different working principles, it can be divided into volumetric water pumps, vane pumps and other types. Positive displacement pumps use changes in the volume of their studios to transfer energy; Vane pumps use the interaction between rotary vanes and water to transfer energy, and there are types of centrifugal pumps, axial flow pumps and mixed-flow pumps.

The head of a pump refers to the vertical height of the water flow that the pump can lift when it is running. It is one of the important parameters to measure the performance of a water pump. Head is usually expressed in meters (m). The higher the head, the stronger the pump's ability to transport liquids.

It is important to note that the head is not equal to the actual height at which the pump can pump the water. In fact, the head mainly consists of two parts: one is the pressure difference between the suction inlet and the outlet of the pump, and the other part is the pipe resistance that the pump needs to overcome.

Therefore, in practical applications, the head of the pump needs to be determined in combination with the piping system and other conditions.

Head refers to the effective head of the pump. That is, the net added value of energy obtained by a unit mass of fluid through the pump. It is an important working performance parameter of the pump, also known as the pressure head. It can be expressed as an increase in the pressure, kinetic, and potential energy heads of a fluid.

The noun is explained as "pump head – the ability to overcome resistance". It is also important to understand that it is not only the resistance of the maximum vertical height, but also the delay resistance of the flow, that is, the resistance of the pipe. Therefore, when we choose head, we should consider not only the elevation resistance but also the pipeline's own resistance.

The compound head of the pump refers to the pump energy.

The height of the water is usually expressed in h, and the unit is m. The head of the centrifugal pump is based on the center line of the impeller and is composed of two parts. The vertical height from the centerline of the impeller of the pump to the water surface of the water source, that is, the height at which the pump can suck up the water, is called the suction head, referred to as the suction lift; The vertical height from the centerline of the impeller of the pump to the water surface of the outlet pool, that is, the height at which the pump can press the water up, is called the pressurized water head, referred to as the pressure range.

i.e. pump head =

Suction head. Pressurized water head.

It should be pointed out that the head indicated on the nameplate refers to the head that can be generated by the pump itself, and it does not include the loss head caused by the frictional resistance of the pipeline water flow. When choosing a water pump, pay attention not to be ignored. Otherwise, you won't be able to pump water.

The effective energy obtained per unit weight of liquid after it has flowed through the pump. It is an important working performance parameter of the pump, also known as the pressure head. It can be expressed as an increase in the pressure, kinetic, and potential energy heads of the fluid, ie.

h=(p2-p1) g+(c2 2-c1 2) 2g+z2-z1 where h——head, m;

P1, P2 - the pressure of the liquid at the inlet and outlet of the pump, Pa;

C1, C2 - the flow rate of the fluid at the inlet and outlet of the pump, m s;

z1, z2 - inlet and outlet height, m;

– density of liquid, kg m3;

g – acceleration due to gravity, m s2.

Head refers to the pump bai

Apply du to the water

The physical pressure, the pressure zhimpa is converted to the theoretical pressure dao with the meter as the single internal position, which is what you see in the lifting capacity, simply put, without considering the output pipe loss and the self-weight counterpressure generated by the water, the water of the pump can be pressed to the vertical height of the head marked on the nameplate. The head and flow rate marked on the nameplate of the pump are not fixed, in fact, it represents the best value of pump performance, the head and the flow are inverse to each other, the flow rate decreases when the head is high, and the head decreases when the flow rate is high.