The mere presence of a well does not mean that a country house or cottage will be sufficiently provided with water. Even in the best scenario, when the water pressure is enough to lift the pole to the surface, the autonomous system in the house will not function. In order for water to flow from all taps and household appliances to work, the minimum reserve should be 2.5 atmospheres, which is quite adequate borehole pump.
Before you go shopping, you need to make the correct calculation of the operation of the well pump. It is short-sighted to buy a pump that cannot cope with the load, as well as to choose a “sophisticated” model whose power is enough for 3 wells like yours. In both cases, the purchase will be unjustified, and in both cases you will waste your money. We will look at how to carry out the calculation and how to use it as productively as possible in the conditions of a summer house or cottage.
Preliminary parameters
Before you decide to buy submersible pump, it is necessary to take measurements of the well itself and understand which unit will be the most the best option. So we measure:
- hole depth;
- dynamic liquid level to determine the flow rate of the opening;
- statistical water level - the distance from the surface to the liquid surface;
- borehole pipe diameter.
To obtain water for domestic purposes, the best option would be a submersible pump - centrifugal or vibration, depending on the operating principle provided in the device. For deep wells It is not recommended to use a vibration device without a casing, since constant vibration will lead to shedding of sand and soil, gradual filling of the well and clogging of the pump.
Required water pressure
Let's start by calculating the required flow, which is the sum of all consumers available on the site. In addition, you need to analyze how much a person uses liquid and calculate maximum flow water.
We need to find out what pressure will be when working with deep well pump. To determine this indicator, it is better to carry out a couple of simple calculations, which will include the dynamic depth of the opening at a certain device performance, as well as the pressure loss and the height where the consumers are installed. These parameters are individual in nature, and therefore we can only talk about optimal performance: To maintain a normal pressure of 2.5 bar, the device must provide 70 m of liquid supply height.
Consumption rate
So, first you need to choose the type of equipment, which can be submersible or self-priming. And to correctly determine what is right for you, you should carefully study all the characteristics and parameters. If there is a ready-made object on which you want to install equipment, then there must be a project.
Let's return to household needs. It is generally accepted that the average water requirement per person is 200 ml. If these 200 ml are consumed in a couple of hours, then a family with 4 people can consume about 0.5 m 3 / h. If water is used for additional needs, then consumption will increase to 1.5 m 3 / h.
Formula for calculating a pump for a well
Let's take a closer look simple example. We have a family of 4 people. Let's say they live in own home outside the city, and for their site we will take equipment whose load is 1.7 m3/h. We need to find out whether there will be enough pressure to supply water to the second floor of the house in the bathroom. To carry out calculations you need to know:
- standard value, let's denote it P and assume that it is 2.5-3 atm;
- the difference between the strongest point of water withdrawal and the dynamic level, which we will call ∆H;
- a value that shows the size of hydraulic losses - ∑∆P
We derive the general formula by which the pressure is calculated: H = ∆H + 10.2xP + ∑∆P and obtain the size of the minimum pressure N.
After all measurements have been taken, it is necessary to select equipment. It is worth choosing a unit that, in terms of its characteristics, will be closest to those that the calculation formula showed us. In addition, be sure to compare the parameters of the well itself and the pump.
If you are using a submersible pump, its diameter should be smaller than the hole.
Electrical characteristics
Electrical output is important aspect when calculating the power cable, as well as special electrical devices for guard. There is one small nuance that distinguishes this characteristic from all others. To determine the electricity load, it is not necessary to carry out any additional calculations. It is enough to study the technical characteristics of the equipment, which are usually indicated in the passport. Also, so that the work is carried out normally and with high level safety, it is necessary to match the cable and the electrical power that the unit consumes.
When calculating the power of a well pump for water supply to an area, you need to take into account a number of nuances, and therefore, if you are not confident in the correctness of the calculations, it is better to contact specialists.
What criteria should you follow when choosing a pump?
For those who are not satisfied with the performance of old equipment, a couple of tips on how to choose a well pump that will be more productive will be useful. Let’s say that by choosing a centrifugal pump, you can avoid the fact that the well will be filled with sand. In order to obtain high quality water, it is better to install the device no less than 1 meter from the filter. When water consumption, it is necessary to take into account not only average figures, but also peak values. In addition, you need to ensure that there is enough water for technical needs. Good pressure will be provided by a pump with a power reserve of approximately 20%.
A decrease in pressure can be caused by the appearance of silt in the well or the use of filters. Independent calculations of a pump for a well based on pressure power may not be accurate, and therefore it is better to use the help of professionals in this matter.
Also important: the diameter of the device must be at least 1 cm smaller than the well in which it is used. It will do easier installation and will also increase the operating time of the pump.
In addition, in addition to the main characteristics, when choosing a device, you should pay attention to its immersion depth and the pressure that the device creates. The equipment may vary in diameter. There are those in which the indicators are small - 100 mm. They appearance may resemble a kind of elongated cylinder, which can be lowered to the bottom of our well hole without any problems. There are also devices for wells, the diameter of which is larger, but the immersion depth is less. But they can be noted for the efficient use of engine operation.
Before installing the device, you must take a hose or pipe required length and size in order to connect it to the inlet of the pumping equipment. It is selected depending on the immersion depth. The presence of a check valve is also important, so if it is not included in the standard package, it is better to install it yourself. If this part is missing, the liquid will return back into the well.
It is better to entrust the installation of water pumping devices to professionals, since installation work quite complex. In addition, you need to know that the equipment itself will not be able to perform a direct function. For this you need additional auxiliary devices, such as:
- Membrane tank;
- Electronic control unit;
- A sensor that shows pressure;
- Pressure gauge;
- coupling;
- Clamps.
Once you have all the parts, you can begin installing the unit. Before starting it, you need to check the pressure in the tank and that all connections are correct. When all installation work is done, the device can begin to function and supply water from the well. This unit makes it possible to provide water supply at any summer cottage, so it is in demand in the market. In addition, its capacity allows it to be used on an industrial scale.
The basis of any water supply system is right choice pump and calculation of pump power for water wells, since the quality of water, the reliability and efficiency of the system as a whole, as well as the comfort of use will depend on these factors in the future. Below we will describe how to calculate pump power according to the rules and methods used in practice by experts in this field.
To calculate the power of a pump for water wells, you can use the calculator for calculating the power of a pump for water wells.
Algorithm for calculating pump power for water wells.
1. The first stage is to choose the type of equipment - self-priming or submersible. In order to determine what you need, you should familiarize yourself in detail with the main characteristics and parameters of the pumps. For example, self-priming pump equipment delivers water to the surface of the earth from depths of about 7 m without the use of an ejector and up to 9 m with a built-in ejector.
There are also special pumps with a remote ejector that can deliver water from depths of about 40 m.
Advice: there is no need to use this kind of equipment, since at the moment of water intake, this type of pump pumps part of the liquid back into the well, wasting excess energy, which is very uneconomical.
2. Advantages of suction pumps:
Can be used as a small pumping station. You just need to connect the equipment to the well and you can pump water;
There is constant access for repairs and diagnostics of equipment, since the pump itself is located on top. He also works in more comfortable conditions, compared to submerged equipment.
3. To decide what type of pump is needed in your case, you need to find out the flow rate of the well itself. Based on this, the pump performance should be 10-30% less. Otherwise water well will constantly silt.
4. To meet specific needs, the minimum power of the equipment must be determined. Yes, for big ones industrial facilities The calculation depends on the number of working personnel and production capacity. Of such kind industrial pumps usually equipped frequency converter or automatic system with soft start.
Calculation of the productivity of pumping equipment for water wells.
For a specific object, the overall productivity is necessarily provided for in the project. For example, for a private household, the amount of water consumption is determined based on regulatory data. It is accepted that on average 200 ml of water is needed per person per day. This takes into account that water consumption will occur in the morning and in the evening.
If we take into account that this standard 200 ml will be consumed in 2 hours, then for a family of 4 people, the average water consumption will be approximately 0.5 m3/h. In addition, if water will also be used for additional needs, for example, watering beds, then this will require 1.5 m3/h. Thus, the total productivity of the equipment must be at least 2 m 3 / h.
An example of calculating pump power for water wells.
This example will show how calculate a pump for a well. Let's say there are 4 people in a family. They live outside the city, in a private house with a garden and vegetable garden. For calculation, we take a pump with a capacity of 1.7 m3/hour.
It is necessary to determine whether the pressure of this pump will be sufficient to deliver water to the bathroom, which is located on the second floor of the house.
Tip: do not forget to take into account the flow rate of the well and compare the power of the pump with it.
N—minimum pressure, m;
P is a standard value and is equal to 2.5-3 atm;
. ∆H is the difference between the maximum point of water withdrawal and the dynamic water level, m. If a suction pump is used, then this value is taken as the distance between the highest point of water withdrawal and the pump equipment itself;
. ∑∆P is a value characterizing hydraulic losses on the pipeline (approximately 10% of its length), filters, corners, tees (15-20%).
After carrying out the calculations, you need to select a pump model that, in terms of its characteristics, comes closest to the previously calculated indicators. Next, you need to compare the diameters of the well and pump. If a submersible pump is used, its diameter should be smaller. If the instructions provide for the installation of a downhole adapter, then you need to make sure that the pump passes where its static component is located.
Recommendations for calculating pump power for water wells.
Sometimes people ask questions like this: recommend a good well pump, since the old one no longer copes with its task.
Answers to the most common questions will be given below in the form of recommendations from experts.
1. When choosing a pump, try not to give preference to options with vibration, although their price is lower. This type of equipment is more suitable for ordinary wells, since their communications are covered with sand over time.
2. It is better to choose centrifugal type submersible pumps. This will prevent the well from filling up with sand.
3. To obtain better quality water, install the pump at a distance of at least 1 m from the filter.
4. When using water, it is necessary to take into account not only average values, but also peak values. Also make sure that there is enough water for technical purposes (watering the garden, washing the car, etc.).
5. To ensure good water pressure, you must select a pump with a power reserve of 20% of the selected value. This will create overpressure in the system and provide excellent water pressure. Factors such as silting of water pipes and the use of filters contribute to a decrease in pressure. It will not be possible to carry out this type of calculation yourself without the necessary knowledge and skills, so it is better to turn to professionals for help.
6. Try to lower the pump 1 m below the dynamic water level. This measure will prevent the engine from being cooled by water coming from outside.
8. Please note that the diameter of the pump must be at least 1 cm smaller than the diameter of the well itself. This will extend the life of the pump and simplify the procedure for installing/dismantling equipment. For example, if a well has a diameter of 76 cm, then the pump must be selected with a diameter of no more than 74 cm.
Conclusion for calculating pump power.
At calculation of pump power for organizing wells for the purpose of water supply it is necessary to take into account many different nuances that affect its operation and operation. If you are not sure about own strength, then entrust this matter to specialists.
Depending on the purpose of the well, it can be equipped with other types of pumps:
- Ordinary downhole units designed for placement in artesian wells. Capable of supplying clean drinking water from great depths.
- Well pumps. Such units can be equipped with any wide wells designed to collect water for a variety of needs, including providing water supply to the house, irrigation, etc.
- Drainage. Designed for installation and use in sewer wells.
What else should you pay attention to when choosing equipment?
In order for the selected well pump to fully meet the owner’s requirements and to perform all the tasks assigned to it with dignity, a number of additional criteria must be taken into account, namely:
You need to measure the depth of your well, and then, when studying the characteristics of the pump, check the measured value with the maximum permissible immersion depth according to the passport. A large selection of submersible pump models with a wide variety of characteristics are available for sale, so you can easily select the appropriate unit.
Dynamic water level in the well. The productivity of the source on the site directly depends on this important indicator. This characteristic indicates the maximum possible distance between the surface of the water and the ground during continuous operation of the equipment. It is important to determine the volume of water that the source will be able to produce in a certain time period. If after 30 minutes of work there is still a sufficient amount of water above the surface, then this is a very good indicator.
The static water level in the source indicates the distance between the surface of the bottom and the water. You can easily determine it on your own. To do this, you need to not use the well for several days, and then lower a load into it, tied to a sufficiently long and strong rope. First make marks on the rope to calculate the height. Once the weight reaches the surface of the mirror, you will hear a splash. Record the elevation and then subtract the static level from the total depth. This will determine the value of the water column.
The diameter of the well on the site is also very important, since the pump must be selected taking into account the parameters of the well. Otherwise, you simply will not be able to use it effectively.
You need to decide on something like water consumption before you start drilling a well. When calculating, you can use the data given earlier or the average value, according to which one person consumes about 200 liters of water per day. The presence of children and pets, as well as the nature of living in the house, must be taken into account, i.e. Will people live in it permanently or will they come for a while. In the calculation, you need to take into account the presence of a greenhouse, vegetable garden, orchard and other plantings. As a rule, 2000 l/day is enough for all this. Equipment capable of dispensing 40 liters of water per minute has similar characteristics.
An equally important parameter is pressure. You can calculate it yourself. To do this, you need to calculate the depth of the well, increase the resulting value by 30, and then add another 10% of it to the result. For example, a well on a site has a depth of 45 m. The calculated value of the water column for such a well will be 75 m. Add another 10% and you get a value of 83 m. For this example, you need to select equipment that can provide a pressure of 90 m.
When choosing such equipment, you need to pay special attention to its cost. At this stage, experts advise paying attention not only to the price of the pump itself, but also to the cost various kinds additional equipment. Installation is carried out using an automatic pump operation, a stainless steel cable, and additional fittings. It is not recommended to buy suspiciously cheap equipment and components from little-known manufacturers. But it doesn’t always make sense to buy overly expensive units. The best option- This is medium-cost equipment with optimal values prices and quality.
Majority autonomous systems heating systems that are used for heating country houses and dachas are today equipped with circulation pumps. In order to achieve the required results when installing such a hydraulic machine, it is necessary to perform a preliminary calculation circulation pump for the heating system and, based on the obtained values, select pumping equipment with the appropriate characteristics.
Areas of use of circulation pumps
The main task of the circulation pump is to improve the circulation of coolant through the elements of the heating system. The problem of already cooled water entering heating radiators is well known to residents of upper floors apartment buildings. Such situations are associated with the fact that the coolant in such systems moves very slowly and has time to cool down before reaching the areas heating circuit located at a considerable distance.
When used in country houses Autonomous heating systems in which water circulates naturally can also encounter a problem when radiators installed at the farthest points of the circuit barely heat up. This is also a consequence of insufficient coolant pressure and its slow movement through the pipeline. The installation of circulation pumping equipment allows you to avoid such situations both in apartment buildings and in private houses. By forcibly creating the required pressure in the pipeline, such pumps provide high speed movement of heated water even to the most distant elements of the heating system.
The efficiency of a heating system with natural circulation of liquid carrying thermal energy, manifest themselves in cases where they are used to heat houses small area. However, if you equip such systems with a circulation pump, you can not only increase the efficiency of their use, but also save on heating by reducing the amount of energy consumed by the boiler.
In terms of its design, the circulation pump is a motor whose shaft transmits rotation to the rotor. A wheel with blades is installed on the rotor - an impeller. Rotating inside the working chamber of the pump, the impeller pushes the heated liquid entering it into the discharge line, forming a coolant flow with the required pressure. Modern models of circulation pumps can operate in several modes, creating different pressures of the coolant moving through them in heating systems. This option allows you to quickly warm up the house when cold weather sets in by running the pump on maximum power, and then, when the whole building has formed comfortable temperature air, switch the device to economy mode.
All circulation pumps used to equip heating systems are divided into two large categories: devices with a “wet” and “dry” rotor. In pumps of the first type, all rotor elements are constantly in the coolant environment, and in devices with a “dry” rotor, only a part of such elements are in contact with the pumped medium. Pumps with a “dry” rotor are distinguished by greater power and higher efficiency, but they make a lot of noise during operation, which cannot be said about devices with a “wet” rotor, which emit minimal amount noise.
Why do you need to do the calculation?
A circulation pump installed in a heating system must effectively solve two main problems:
- create such a liquid pressure in the pipeline that will be able to overcome the hydraulic resistance in the elements of the heating system;
- ensure constant movement of the required amount of coolant through all elements of the heating system.
In order for the circulation pump to be able to cope with the above tasks, such a device should be selected only after the heating calculation has been made.
When performing this calculation, two main parameters are taken into account:
- the building's total heat energy requirement;
- the total hydraulic resistance of all elements of the created heating system.
Table 1. Thermal power for various rooms
After determining these parameters, you can already perform the calculation centrifugal pump and, based on the obtained values, select a circulation pump with the appropriate technical characteristics. A pump selected in this way will not only provide the required coolant pressure and its constant circulation, but also operate without excessive loads, which can cause rapid failure of the device.
How to correctly calculate pump performance
Such an important parameter of a circulation pump as its performance indicates how much coolant it can move per unit of time. Calculation of the performance of the circulation pump, which is designated by the letter Q, is carried out using the following formula:
Q = 0.86R/TF–TR.
The parameters used in this formula are shown in the table.
Tables from text
The amount of heat required by the premises of a house to heat them, which is designated by the letter R, is determined depending on the climatic conditions of the area in which such a house is located. So, for houses that are operated in European climates, they choose following values of this parameter:
- private houses of small and medium size - 100 kW per 1 m 2;
- apartment buildings– 70 kW per 1 m 2 area of their premises.
In the event that the calculation of heating pump performance is carried out for buildings with low thermal insulation characteristics, the value of thermal power substituted into the formula should be increased. For production premises, as well as rooms located in buildings with good thermal insulation, the value of the parameter R is taken equal to 30–50 kW/m2.
How to calculate hydraulic losses of a heating system
The choice of a circulation pump based on its power and the pressure it creates, as mentioned above, is also influenced by such an important parameter of the heating system as the hydraulic resistance, which is created by all elements of its equipment. Knowing the hydraulic resistance created separate elements heating system, you can calculate the suction height of the pump and, guided by this parameter, select the equipment model according to power and created pressure. To calculate the suction height of the pump, which is designated by the letter H, the following formula is needed:
H = 1.3x(R1L1+R2L2+Z1……..Zn)/10000.
The parameters used in this formula are shown in the table.
The values of R1 and R2 used in this formula should be selected using a special information table.
Values of hydraulic resistance created various devices, which are used to equip heating systems, are usually indicated in the technical documentation for them. If there is no such data in the device passport, then you can use the approximate values of hydraulic resistance:
- heating boiler – 1000–2000 Pa;
- sanitary mixer – 2000–4000 Pa;
- thermal valve – 5000–10000 Pa;
- device for determining the amount of heat - 1000–1500 Pa.
There are special information tables from which you can determine the hydraulic resistance for almost any element of heating system equipment.
Knowing the suction height, which is calculated using the above formula, you can optimally select pumping equipment based on its power, and also determine what the pump pressure should be.
How to choose a circulation pump by the number of speeds
Usually modern models circulation pumps are equipped with a control mechanism that allows you to change the speed of their operation. Using such a mechanism, which usually has three stages of adjustment, you can adjust the pump according to the flow rate of liquid supplied to the heating system. So, when there is a sharp cold snap outside and, accordingly, in the house, the pump can be turned on at maximum speed, and when it warms up, choose a different mode.
The control element used to change the speed of the circulation pump is a lever on the body of the device. Some models of circulation pumps are equipped with an automatic speed control system, which varies depending on the temperature regime in room.
The above technique is just one example of performing the calculations that are necessary in order to select a circulation pump for a warm floor or heating system. Specialists involved in heating systems use various methods for calculating pump pressure (as well as performance and other parameters of such devices), which allow them to select such equipment according to its power and the pressure created. In many cases, the owner of the house in which it is necessary to install heating system, you don’t even have to ask questions about how to calculate the pump power and how to select pumping equipment. Many manufacturers provide the services of qualified specialists or offer the use of online services for calculating the parameters of the circulation pump and its selection for heating systems or underfloor heating.
