Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video

Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video Work to create a well in the adjoining area provides for drilling and strengthening the head. Upon completion, the company that executed the order draws up a document for the well. The passport indicates the parameters of the structure, characteristics, measurements and calculation of the well.

The procedure for calculating the well

The company's employees draw up a protocol for the inspection of wells and an act of transfer for use.

The procedures are mandatory, since they make it possible to obtain documentary confirmation of the serviceability of the structure, the possibility of putting it into operation.

Geological parameters and technological characteristics are entered into the documentation:

  1. Constant water level in the well at rest. The measurement is carried out in the metric system from the ground to the upper water level.
  2. Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video The depth of the water layer, or the height of the casing filter above the bottom of the well.
  3. Water level in dynamics during pump operation, while the water level drops by a couple of meters. This data is required to calculate the pump lowering depth.

  4. Parameters of water return under load, which are obtained when calculating the parameters. The characteristics are called well flow rate.

Calculation of the productivity of a well for water is estimated by determining the flow rate.

To calculate the flow rate, use the standard formula:

D = (V h x H): (h c - h d )

The obtained value makes it possible to get an idea of ​​the water intake capacity.

Explanation of the formula:

  • h c - static water level;
  • h d - dynamic water level.

  • D - flow rate;
  • V - pump productivity;
  • H - water column height;

Well calculation example:

  1. well depth - 60 m;
  2. pump productivity (V) - 2 m 3 / h;
  3. level c static (h c ) - 40 m;
  4. dynamic level (h d ) - 32 m;
  5. water column height (H) 60 - 40 = 20 m.

After data substitution, the calculation of the flow rate is obtained - 5 m 3 / h.

Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video

In order to check the correctness of counting, start a trial pumping of water at a large pump power. This allows you to improve the indicators of dynamics

In practice, the second formula is used for calculation accuracy. After receiving the flow rate values, the average indicator is determined, which allows you to accurately determine the increase in productivity with an increase in dynamics by 1 m.

Calculation formula:

D beats = D2 - D1 / H2 - H1

  • Dsp - specific flow rate;
  • D1, H1 - indicators of the first test;
  • D2, H2 - indicators of the second test.

Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video The lower the fluid loss level, the greater the level difference, and the smaller the result of the value.

Based on the indicators, it is concluded that the well quality is poor.

Only with the help of calculations is the correctness of the research and drilling of the water intake confirmed.

Design characteristics in practice

Familiarity with the methods of calculating a water intake well provokes the question - why does this knowledge need an ordinary user of a water intake? It is important to understand here that fluid loss is a single way to assess the performance of a well in order to satisfy the residents' need for water before signing the acceptance certificate.

To avoid further problems, proceed as follows:

  1. The calculation is carried out taking into account the number of residents of the house. The average water consumption is 200 liters per person. This is added to the costs of household needs and technical use. When calculating for a family of 4 people, we get the highest water consumption of 2.3 cubic meters / hour.

  2. In the process of drawing up a contract, the project takes the value of the productivity of water intake at a level not less than 2.5 - 3 m 3 / h.
  3. After the completion of the work and the calculation of the well level, water is pumped out, the dynamics are measured and the water loss is determined at the highest flow rate of the home pump.

Problems can arise at the level of calculating the flow rate of a well for water in the process of control pumping by a pump belonging to the contractor's company.

Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video The force of water return by a low-power pump and a unit with a given productivity can have striking differences.

The inflow rate at a low flow rate can satisfy the maintenance of a dynamic rate that is sufficient for the pump productivity.

Pumping out water by a unit with a large capacity, even with optimal flow rates in the first experiment, the filling speed may not be enough to maintain the water level in dynamics.

What is the threat? In the dry season, taking into account the optimal water intake, there will not be enough water to meet the needs of the house.

For an optimal calculation of the flow rate, it is necessary to carry it out for pumps with different powers.

For this, use the formula:

Dу = (U 2 - U 1 ): (h 2 - h 1 )

  • Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video U 1 - weak pump flow;
  • U 2 - powerful pump flow;
  • h 1 - level decrease indicator water for a weak pump;
  • h 2 - an indicator of a decrease in the water level for a powerful pump;
  • Dу - the height of the water column.

The calculation of fluid loss is carried out by multiplying the value of the specific flow rate by the height of the column, from the surface of the water to the entrance to the pump opening for the intake.

The static level is determined using a float or low weight, which is hooked at a meter distance, using a nylon cord. This method is used to measure the depth of water in a well. When lowering the weight, you need to make a mark on the cord. The weakest point is determined and a statics indicator is obtained.

The distance to the pump hole is measured along the length of the hose and added to the body length.

Well productivity is measured by m 3 / hour (second, day). The well flow rate is determined when choosing the productivity of the pump for water. Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video

Expert recommendations

Moments that determine the rate of filling the well with water:

  1. The volume of the water layer;
  2. The rate of its decrease;
  3. The depth of the groundwater and changes in the level depending on the season.

Wells with water intake productivity less than 20 m 3 / day.

, are considered unproductive.

Reasons for low flow rates:

  • peculiarities of the hydrogeological situation of the area;
  • groundwater changes depending on the season;
  • clogging of filters;
  • blockages in the pipes that supply water upward or their defloration;
  • natural wear of the pump.

If problems are found after putting the well into operation, this indicates that there were errors at the stage of calculating the parameters. Therefore, this stage is one of the most important that should not be overlooked.

Methods for calculating well flow rates and pump performance parameters - Formulas for calculating and operating a well for water + Video In order to increase the productivity of the water intake, the depth of the well is increased in order to open an additional layer of water.

Also, they use methods of pumping water empirically, apply chemical and mechanical effects on the water layers, or transfer the well to another place.

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