RU2473048C1 - Automated information system for measurement and analysis on real time basis of coolant flow rate on manifold pump stations - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: automated information system comprises pump stations with pressure sensors. The automated system is additionally equipped with power sensors and a system of data transfer combining outlets of all sensors with an information center comprising a PC and a data base by pressure and power with coolant flow rate measurement with data release by flow rate and pressure in digital and graphical form using a new flow rate characteristic. At the same time the operating pump set is simultaneously a flow meter. A recalculated working characteristic is introduced into a data base with account of whether a synchronous electric motor or an asynchronous electric motor is used as a drive, when working characteristics are previously recalculated using reduction formulas. When using a synchronous electric motor by working characteristics, a new flow rate characteristic is calculated - M-Q with flow rate coefficients M. For this purpose on the basis of passport data, using head H to build a pressure characteristic p-Q.

EFFECT: simplified process of measurement and analysis on a real time basis of parameters of pump plants and entier automated information system.

13 dwg

Description

The invention relates to the field of control of the heat supply system of cities and industrial facilities. Modern heating systems are characterized by the following development trends:

- increasing requirements for providing consumers with heat;

- increase in the proportion of heat in hot water supply;

- providing buildings with heat during their increased number of storeys;

- reducing the mass of wall structures and increasing the percentage of glazing of modern buildings;

- widespread use of computer technology to control heat supply systems;

- construction of "Intelligent buildings" with the widespread use of communications.

These features of the development of modern heat supply systems require a different approach to their management; therefore, further optimization of heat supply systems is associated with solving a number of major problems requiring new scientifically based technical, economic and technological solutions. The most important of these problems is the introduction of automated information systems for real-time process control by computer. To do this, you must:

- The introduction of a set of automated information systems that allows you to receive in real time the necessary information about the process with automatic recording and analysis of the results;

- the introduction of information technology based on mathematical models of managed objects, computer facilities and the corresponding set of technical means.

The ultimate goal of regulation is to ensure the heat balance in the network when the amount of heat supplied for a certain time by the heat source is equal to the amount of heat energy consumed by the heat consumer, taking into account its losses in the network during transportation from the source to the consumer. The main parameter characterizing the operation of pumping units for pumping coolant is flow.

All known devices for measuring fluid flow contain primary sensors, which must directly be in the flow of the measured fluid and require periodic inspection and calibration on the measuring stand, which complicates their operation.

A known system for measuring the mass flow rate and density of a liquid supplied by a centrifugal electric pump, containing pumping stations with pressure sensors / RF Patent 2119148. A method of measuring the mass flow rate and density of a liquid supplied by a centrifugal electric pump / Krichke V.O., Groman A.O., Krichke V.V. from 09/20/98 /. Adopted for the prototype.

The disadvantage of this system is that it does not contain devices for measuring the temperature of the parameters of the pumping unit, vibration control sensors and other parameters that provide the necessary control.

The essence of the invention is to control the operation of the heat supply system by obtaining and analyzing in real time the flow rate at the central heating points.

The technical result is a simplification of the process of measuring and analyzing in real time the parameters of pumping units and the entire automated information system.

The technical result is achieved by the fact that in the known automated information system containing pumping stations with pressure sensors, the peculiarity is that it is additionally equipped with power sensors and a data transmission system that combines the outputs of all sensors with an information center containing a computer and a database of pressure and power with measuring the flow rate of the coolant with the issuance of data on flow and pressure in digital and graphic form using a new flow characteristic, while working the pump unit is simultaneously a flow meter, the recalculated operating characteristic of the pump unit is entered into the database, taking into account when a synchronous motor or an asynchronous electric motor is used as a drive, in which the operating characteristics are previously recalculated according to the reduction formulas, when using a synchronous electric motor, a new flow characteristic is calculated M-Q with flow coefficients M, for this, according to the passport data for the pressure H, he builds I pQ at a known pressure characteristic of the liquid density p at which the passport is constructed pQ characteristic according to the formula p = ρ · g · H · 10 ^-6 MPa, hereinafter calculated using the flow coefficients M consumables over a range flow rate Q, and on them - the expenditure MQ characteristic according to the formula: M = (N / p) η _ek -N ₀ / p ₀ ) K, where N, p are data taken from the rating sheet, N ₀ , p ₀ power and pressure when the valve is closed for one minute pump output obtained experimentally according to the formula, η _eq = (N ₀ / p ₀₎ / (p ₀₁ / N _01), where N _0, p ₀ - p and passport data _01, N ₀₁ - e ones by data acting on the shaft of each pump N, determined by multiplying the power consumed from the network P _c, on the efficiency of the motor η _ed, power offset based on the calculated value service factor η _eq determine deviations from nominal power values ± ΔN, acting on the shaft pump at its operation at the closed valve with a zero flow rate and developed pressure ± Δp them, and add them to the power values n _n ± ΔN pressure developed by the pump p _n ± Δp when calculating coefficients ienta K convergence, which is determined at a nominal value of flow by dividing the passport consumable coefficient M _n for checking consumable ratio M _p = ((N _n ± ΔN) / (r _n ± Δp)) η _eq - (N _o / p ₀₎ based on the found value of K, the expenditure coefficient M is calculated, by the formula by dividing the coefficient of convergence K by the calculated expenditure coefficient; the volumetric flow rate Q, at a pressure characteristic HQ, calculated at the calculated flowrate Q active head H, and with respect to M _p by the computed value consumable factor M for flow characteristic Q = f (M) is calculated density of the pumped liquid p by dividing the pressure generated by a pump at given flow rate, to the current design head H and coefficient g, the calculation of the flow rate when the pump is driven by an asynchronous electric motor is carried out in the same way, only at first the characteristic of the pump with an asynchronous electric motor it is recalculated using the formula:

for flow: Q ₁ / Q ₀ = (n ₁ / n ₀ ) or Q ₁ = Q ₀ (n ₁ / n ₀ );

или

;for pressure:

or

;

или

,for power:

or

,

where Q ₁ , H ₁ , N ₁ , n ₁ - current values of flow, pressure, power, speed of the pump shaft, and Q ₀ , H ₀ , N ₀ , n ₀ - respectively, their passport values, calculated data for the transmission system are received to a control room in a computer containing the appropriate database, with the help of which all the necessary information on the measurement and analysis of the costs of pumping units is calculated.

“A method of measuring the mass flow rate and density of a liquid supplied by a centrifugal electric pump” (Patent 2119148 from 10.20.98), does not contain devices for measuring the temperature of the parameters of the pumping unit, vibration control sensors and other parameters that provide the necessary control. The automated information system under consideration provides all the main sensors for measuring and analyzing in real time all the main indicators in the operation of pumping stations with centrifugal electric pumps, such as the coolant flow at main pumping stations - pressure sensors and power sensors, a system that combines the outputs of all sensors with an information center containing a computer and a database of measured parameters, using which the power acting on the shaft of each of us is calculated wasp, by multiplying the power consumed from the network P _c, on the efficiency of the motor η _eq is calculated pressure p generated by the pump, by subtracting the pressure at the pump outlet p _O pressure at its input p _Rin at passport data calculated value consumable coefficient M ₀ at zero flow at the beginning of the performance by dividing the power N ₀ on the pressure p _0, the experimentally determined service factor η _eq of the pump to a closed valve by multiplying the result of dividing mo NOSTA N ₀ on the pressure p ₀ of the pump of the closed valve, taken from the pump performance, the result of dividing the measured pressure values p ₀₁ the measured power value for N pump shaft _01, on operational coefficient η _eq. Deviations of power ± ΔN and pressure ± Δр from the nominal values and in the entire range of nameplate characteristics are added to the pump performance in terms of power N ± ΔN and pressure p ± Δp, calculated in the whole range of passport data, the calculated flow coefficient M _p without convergence coefficient K by multiplying the result of dividing the power N ± ΔN by the pressure value p ± Δp, by the operating coefficient η _ek minus the value of the consumption coefficient M ₀ , we build a graph of the dependence of the passport expenditure coefficient M on the calculated M _p Consumables coefficient M = f (M _p), in the measurement period based on the calculated value M _p characterization M = f (M _p) are determined valid consumable factor M, and the graph Q = f (M) determined by the volumetric flow rate Q using the convergence coefficient K, which is determined over the entire range of characteristics by dividing the nominal passport expenditure coefficient M _n by the estimated expenditure coefficient M _r according to the formula:

where M _n , N _n , r _n , N _o , p _o are the nominal values of the quantities that are taken from the operating characteristics of the pump, with the calculated value of the operating coefficient η _ek and the deviation of these values ± Δp, ± ΔN from the passport when testing the pump to a closed valve, and graphs are constructed η _ec = f (K), K = f (M _p ), or K = M _n / M _p , the found coefficient K is used to calculate the expenditure coefficient M by the formula by dividing the convergence coefficient K by the calculated ratio M _p, the calculated value of a supply flow rate of the characteristic line providers Q = f (M _p) is computed volumetric flow rate Q, at a pressure characteristic HQ calculated at the calculated flowrate actual head H, and through it - p the density of the pumped liquid by dividing the differential pressure created by the pump, to a valid design head H, and the coefficient g, the pump efficiency is calculated by multiplying the pressure by the result of dividing the flow rate by the power, the calculated data for the transmission system are sent to the control room in a computer containing the corresponding database, with omoschyu which are computed with all the necessary information to measure and analyze real-time key performance indicators pumping systems. An automated information system provides continuous monitoring of the operation of each pump unit by continuously measuring and analyzing in real time the volumetric and mass flow rates of liquids

The drawings show:

Figure 1. The layout of the pumping stations of the heating system in Samara.

Figure 2. Performance characteristics of the pump D1600-90 at n = 1450 rpm with impeller diameter D = 540 mm driven by an asynchronous electric motor.

Figure 3. Recalculated working drawings of the pump D1600-90 at n = 1450 rpm with an impeller diameter of D = 540 mm driven by an asynchronous electric motor.

Figure 4. Performance characteristics of the D1600-90 pump at n = 1450 rpm with an impeller diameter D = 540 mm driven by an asynchronous electric motor when the pump parameters deviate from the rated values.

Figure 5. Graphs for determining the coefficient of convergence K from the operational coefficient η _ec .

6. The graph of the flow of coolant at the pumping station No. 1.

7. The graph of the flow of coolant at the pumping station No. 6.

Fig. 8. Pressure graphs at pumping station No. 6.

Fig.9. Schedule of coolant flow rate at pumping station No. 11.

Figure 10. Pressure graphs at pump station No. 11.

11. The graph of the flow of coolant at the pumping station No. 12.

Fig. 12. The graph of the flow of coolant at the pumping station No. 13.

Fig.13. General view of the control center of the Samara heating networks.

Information confirming the possibility of carrying out the invention. The automated system under consideration provides for the use of a directly operating pumping unit as a flowmeter, the operating characteristics of which are shown in Fig. 2, and the recalculated operating characteristics together with a new flow-rate characteristic are given in Fig. 3, while to measure the flow it is only necessary to measure the pressure created by the pump p in operating mode, and the active power N on the pump shaft and after a certain time the active power N ₀ and pressure p ₀ created by the pump with the valve closed e at its exit.

To build the operating characteristics of a pump driven by an induction motor, it is first necessary to recalculate the characteristics depending on the frequency of rotation of the pump shaft according to the reduction formulas:

for flow

for pressure

for power

where Q ₁ , H ₁ , N ₁ , n ₁ - current values of flow, power, pressure, speed, a Q ₀ , H ₀ , N ₀ , n ₀ - respectively, their passport values at idle pump, for example 1500, 3000 rpm

The passport characteristic of the pump is issued by the manufacturer. However, during the operation of the pumping units, their repair and different operating conditions, the actual characteristics may differ from the passport ones. In this regard, the characteristics of the pump obtained after the repair of the pump and the possible replacement of some of its components are called basic, with which later the characteristics obtained during the current operation of the pump unit are compared. The characteristics obtained during the operation of the pump are called current. Changing the speed of an asynchronous electric motor during its operation, from its idling n ₀ to the pump at its rated rated capacity with frequency n _n :

n = n ₀ -n _n , rpm

For the pump D1600-90 under consideration at n = 1450 rpm with an impeller diameter D = 540 mm and a drive from an induction motor

n _p = 1500-1450 = 50, rev / min.

To determine the frequency of rotation of the pump shaft of the electric motor per 1 kW of power, we take the value of the power on the pump shaft P ₂ at its rated speed, then the calculated frequency n _p will be equal to

In our example, when n _n = 1450 rpm at a power of 500 kW

Then each power value N at a certain flow rate is multiplied by n _p and subtract the obtained value from the value of the rotational speed at idle of the electric motor n ₀ .

n = n ₀ - (n _p · N).

In our case, an example of calculating the current values of the speed for various power is given below:

n ₀ = 1500- (220 · 0.101) = 1500-22.22 = 1477.78, rpm

n ₁ = 1500- (250 · 0.101) = 1500-25.25 = 1474.75, rpm

n _n = 1500- (495 · 0.101) = 1500-49.995 = 1450.0, rpm

Next, we find the ratio n ₁ / n ₀ , where n ₁ is the current value of the number of revolutions of the pump shaft, n ₀ = 1500 rpm is the value of the number of revolutions of the pump shaft when idling, taken from its nameplate characteristics. For example, we determine n ₁ / n ₀ according to three values of the pump performance:

For example, we determine the estimated flow rate Q *:

по трем рабочим характеристикам насоса:Defined for example

according to three pump performance characteristics:

Determine the design pressure N *:

For example, we determine (n ₁ / n ₀ ) ³ according to three pump performance characteristics:

We determine the calculated value of N *:

We determine the pressure p at three points of the recalculated operating characteristic:

p ₀ = ρ · g · H ₀ · 10 ^-6 = 998.8 · 9.81 · 108.37 = 1.06185, MPa,

p ₁ = ρ · g · H ₁ · 10 ^-6 = 998.8 · 9.81 · 104 = 1.019, MPa,

p _n = ρ · g · H _n · 10 ^-6 = 998.8 · 9.81 · 83.17 = 0.8149, MPa.

The calculated data on the number of revolutions of the shaft, pump, flow, pressure and power are placed in table 1.

Table 1 The calculated data for the pump D1600-90 at n = 1450 rpm with the impeller diameter D = 540 mm driven by an asynchronous electric motor Q _n m ³ / h N _n kW N _n n n ₁ rpm Q * = Qn ₁ / n ₀ H * = H * (n ₁ / n ₀ ) ² N * = N · (n ₁ / n ₀ ) ³ p, MPa M, kW / MPa 0 220 110 1477.78 0 108.37 210.37 1,06185 198.1-198.1 200 250 108 1474.75 196.63 104.0 237.4 1.019 34.94 400 280 107 1471.72 392.44 103.0 274.72 1,0092 76.1 600 320 106 1467.28 586.92 101.43 299.52 0.9938 103.29 800 355 105 1464.15 780.88 100,041 330.15 0.98 138.79 1000 390 104 1460.61 973.7 98.26 360,046 0.963 175.78 1200 425 102 1457.07 1165.65 96.25 389.54 0.943 215.0 1400 455 93 1454.04 1357.1 87.39 414,441 0.856 286 1600 495 89 1450.0 1546.72 83.17 447.16 0.8149 350.63 1800 530 80 1446.47 1735.76 74.39 475.24 0.729 453.8

In table 1, the number of revolutions varies with the load - n ₁ current revolutions, n ₀ - passport values of the pump at the rated frequency at idle. In this case, n ₀ = 1500 rpm.

The calculated frequency is -

In this example, the operational coefficient η _ek and the convergence coefficient K are equal to zero.

When using an induction motor to drive the pump, the flow coefficient M is calculated by the usual formula

however, no recalculations of power, pressure and flow are made, since they automatically change during the measurement. An example of calculating the expense coefficient M:

As a result of the analysis, it can be concluded that when using an asynchronous electric motor as a pump drive, the change in its shaft speed from the load is taken into account by the conversion characteristic and, therefore, no additional calculations should be made during the flow measurement. Data for graphing are given in tables 2 and 3.

table 2 Data for plotting the D1600-90 pump at n = 1450 rpm with impeller diameter D = 540 mm driven by an induction motor *, n ₁ / n ₀ Efficiency% H *, (n ₁ / n ₀₎ ² N *, (n ₁ / n ₀ ) ³ p, Pa M, kW / MPa 0 0 108.37 220 1,06185 198.1-198.1 196.63 thirty 104.0 250 1.019 34.94 392.44 fifty 103.0 280 1,0092 76.1 586.92 60 101.43 320 0.99.38 103.29 780.88 70 100,041 355 0.98 138.79 973.7 76 98.26 390 0.963 175.78 1165.65 83 96.25 425 0.943 215.0 1357.1 85 87.39 455 0.856 286 1546.72 85 83.17 495 0.8149 350.63 1735.76 78 74.39 530 0.729 453.8

Table 3 The performance characteristics of the D1600-90 pump prepared for plotting at n = 1450 rpm with the impeller diameter D = 540. mm driven by an induction motor Q *, n ₁ / n ₀ Efficiency% H *, (n ₁ / n ₀ ) ² N *, x5 (n ₁ / n ₀ ) ³ p, / 100 MPa M, x5 kW / MPa 0 0 108.37 42.07 106,185 0,0 196.63 thirty 104.0 52.92 101.9 12.31 392.44 fifty 103.0 54.94 100.92 15.22 586.92 60 101.43 59.9 99.38 21.66 780.88 70 100,041 66.03 98 27.76 973.7 76 98.26 72.01 96.3 35.16 1165.65 83 96.25 77.91 94.3 43.0 1357.1 85 87.39 82.88 85.6 57.2 1546.72 85 83.17 89.43 81.49 70.17 1735.76 78 74.39 95.05 72.9 90.76

The mathematical description of the graphs shown in figure 3:

N = 1E-4E Q ³ -4E-06 Q ² +0,0326 Q + 42.32, kW. Power.

M = 2E-48 Q ³ -4E-05 Q ² +0.0545 Q-0.4572, kW / MPa. Consumption, coefficient.

p = 4E-08 Q ³ + 1E-45 Q ² -0.01 Q + 105.22, MPa. Pressure.

H = -4E-08 Q ³ + 1E-05 Q ² -0,0111 Q + 103.55, m.

Efficiency = 1E-48 Q ³ -1E-05 Q ² +0.1433 Q + 2.2061,%. Efficiency.

We will calculate the parameters of the D1600-90 pump at n = 1450 rpm with the impeller diameter D = 540 mm driven by an asynchronous electric motor if they do not comply with the rating data, the power is 10 kW more and the pressure 0.2 MPa more which are considered in table 4.

Table 4 Pump parameters D1600-90 at n = 1450 rpm with impeller diameter D = 540. mm driven by an induction motor when deviating from the passport data Q *, ^m3 / hour H * m N *, x5 kW p, / 100 MPa M, x5 kW / MPa Efficiency% 0 108.37 46.07 126,185 0 0 196.63 104.0 51.48 121.9 12.31 37 392.44 103.0 58.95 120.92 15.22 47 586.92 101.43 63.9 119.38 21.66 60 780.88 100,041 70.03 118 27.76 70 973.7 98.26 76.01 116.3 35.16 75 1165.65 96.25 81.91 143 43.0 84 1357.1 87.39 86.89 105.6 57.2 86 1546.72 83.17 93.43 101.49 70.17 84 1735.76 74.39 95.05 72.9 90.76 77

According to table 4, we construct graphs.

The mathematical description of the graphs shown in figure 2 and in table 3:

M = 2E-08 × 3-3E-05 × 2 + 0.0494x + 0.1131, kW / MPa. Consumption, coefficient.

N = 2E-09 × 3-5E-06 × 2 + 0.0327x + 42.62, kW. Power.

N = -1E-08 × 3 + 2E-05 × 2-0.0189x + 125.97, m. Head.

p = -1E-08 × 3 + 2E-05 × 2-0.0177x + 107.78, MPa. Pressure.

Efficiency = 7E-09 × 3-7E-05 × 2 + 0.1349x + 2.4117,%. Efficiency.

6. An example of calculating the pump’s operating characteristics if there is a discrepancy between the current operating data and the passport rating, with the pump driven by an induction motor.

The main discrepancies in power and pressure are +10 kW in power and +0.1 MPa in pressure. For this operating mode, the characteristics of the pump D1600-90 at n = 1450, rpm with the impeller diameter D ₂ = 540 mm are given in table 4 and in the graph of figure 4.

1. Determine the service factor η _eq

2. Calculate the coefficient of convergence K for an induction motor

K _asin = -0.6385η _eq +1.7007.

K _asin = -0.63851085 + 1.7007 = 1.0622,

or by calculation according to the formula, or according to the graph of figure 5:

where M _n , N _n , r _n , N _o , p _o are the nominal values of the values that are taken according to the graph shown in figure 2, from the operating characteristics of this pump, with the calculated value of the operating coefficient η ^ek and the deviation values of these values ± Δp, ± ΔN from the passport when testing the pump for a closed valve.

3. Calculate the expense coefficient M

4. Calculate the flow rate Q

From the table, we substitute the values of flow rate and operating coefficient in the formula

5. Calculate the difference in flow rate ΔQ with deviation from the passport value.

The difference in the flow rate ΔQ = QQ = 1735,71-1586,65 _eq = 149.11 m ³ / h

The difference in flow rate of 149.11, m ³ / h was affected by a change in the operating coefficient due to deviations of the pump parameters from the certified values.

6. Calculate the density of the pumped liquid

To do this, with the calculated flow rate and, accordingly, the effective pressure, we find the pressure value from the operating characteristics. We calculate the density of the liquid by the formula:

In our example, at a flow rate of 1546.72 m ³ / h and a pressure of 1.0149 MPa, the head is H = 83.17, m.

This corresponds to the actual data.

7. Calculate the mass flow rate of the liquid.

It is equal to Q _m = ρ · Q · 10 ^-3 t / h, where Q _m t / h - mass flow rate and Q m ³ / h - volumetric flow rate, ρ, kg / m ³ - calculated.

In our case, Q _m = 1546.72 · 1243.9 · 10 ^-3 = 1924, t / h.

This corresponds to the actual mass flow rate.

8. We calculate the current value of the pump efficiency.

The calculation of the efficiency of the pump is done according to the formula:

Efficiency = p · Q · 10 ⁶ / (102 · 3600 N _n ),%, here the pressure is p, kg / cm ² _,

Efficiency = p · Q · 10 ⁵ / (3600 N _n ),%, here the pressure is p, MPa.

In our example, at p = 1.0149 MPa, efficiency = 1.0149 · 1546.72 · 10 ⁵ /(3600 · 467.16) = 93.34%. This efficiency value is close to the actual value.

9. We calculate the power consumed by the pump from the network:

where η _ed - the efficiency of the electric motor is equal to 97,%.

The considered automated information system was introduced in Samara heating networks in 1998 at six central pumping stations No. 1.5, 6, 11, 12, 13, the information obtained for each pump station in the form of flow and pressure is given in the graphs of Figures 6, 7, 8, 9, 10, 11, 12, which are served at the control room shown in Fig.13. Knowledge of flow rate and pressure determine the efficiency of pumping units. As a result of the slightest deviation of the efficiency from the norm, the necessary measures were immediately taken to restore the efficiency, which did not allow an excessive consumption of electricity. During the operation of the system, multiple tests were made to compare the data obtained with ultrasound readings. An example of such comparative tests is given in the attached table No. 5

Table 5 Time Day, hour Consumption, m ³ / h Ultrasound Consumption, m ³ / h Patent method Times of Day Consumption, m ³ / h Ultrasound Consumption. m ³ / h Patent method 8-00 596 627.03 22-00 592.96 586.3 9-00 620.3 620.37 23-00 592.22 595.9 10-00 595.18 607.78 0-00 590 615.18 11-00 580.37 601.18 1-00 600.37 613.7 12-00 598.18 607.78 2-00 607.37 612.96 13-00 587.03 616.67 3-00 604.81 607.03 14-00 584.07 607.78 4-00 605.55 625.92 15-00 592.22 598.9 5-00 607.78 595.18 16-00 591.48 598.9 6-00 590.74 587.03 17-00 589.26 598.9 7-00 584 579.63 18-00 585.55 592.22 8-00 586.3 605.15 19-00 586.29 592.96 Total 14846.14 15072.48 20-00 567.8 591.48 Itolo 593.84 602.9 21-00 590 587.03

The average measured by two methods, the flow rate is 598.37 m ³ / h. The average value of the difference in the obtained data on the flow measurement is ± 0.75%. If we assume that both methods are to blame for this, then the average difference in the measurement results can be assumed to be ± 0.37%.

Over the entire period of the experimental work of the automated information system under consideration, there was not a single case of its failure. This suggests that there is a guarantee of the implementation of this system in all heat supply networks of enterprises, in cities and rural settlements of Russia.

Claims (1)

An automated information system for measuring and analyzing in real time the flow of coolant at the main pumping stations of heating networks, containing pumping stations with pressure sensors, characterized in that it is additionally equipped with power sensors and a data transmission system that combines the outputs of all sensors with a data center containing A computer and a database of pressure and power with a measurement of the flow of coolant with the issuance of data on flow and pressure in digital and graphic form using by calling a new flow characteristic, while the working pump unit is simultaneously a flow meter, the recalculated operating characteristic of the pump unit is entered into the database, taking into account when a synchronous electric motor or an asynchronous electric motor is used as a drive, in which the operating characteristics are previously recalculated according to the reduction formulas, when using synchronous motor performance calculates a new MQ flow characteristic with consumable coefficients M ratios, for this, according to the passport data on pressure Н, the pressure characteristic pQ is constructed, at a known fluid density p, at which the passport characteristic pQ is built according to the formula p = p · g · H · 10 ^-6 MPa, then consumption coefficients are calculated using the flow rate M over the entire flow rate range Q, and according to them the flow characteristic MQ according to the formula: M = (N / p) η _ek - (N ₀ / p ₀ ) K, where N, p are data taken from the passport characteristic; N ₀ , p ₀ - power and pressure with a shutter closed for one minute at the pump outlet, obtained experimentally by the formula η _ec = (N ₀ / p ₀ ) / (p ₀₁ / N ₀₁ ), where N ₀ , p ₀ - passport data, and p ₀₁ , N ₀₁ - experimental data, determined acting on the shaft of each pump N by multiplying the power consumed from the network P _s by the efficiency of the electric motor η _ed , power deviations from the calculated value of the operational coefficient η _ek determine deviations from rated power ± ΔN acting on the pump shaft and during operation of the closed valve with a zero flow rate and developed pressure they ± Ap and add them to the power values N _n ± ΔN, the pressure developed by the pump P _n ± Ap in calculating the convergence factor of K, which is determined at a nominal value of flow by dividing the passport of the expenditure coefficient M _n to the calculated expenditure coefficient M _p = ((N _n ± ΔN) / (r _n ± Δp)) η _ek - (N ₀ / p ₀ ), the found coefficient K is used to calculate the expenditure coefficient M by the formula convergence K on the estimated expenditure coefficient; the volume flow rate Q, according to the pressure characteristic HQ, is calculated with the calculated value of the flow Q of the effective pressure H, and according to M _p , the calculated value of the flow coefficient M, the flow characteristic Q = f (M) calculates the density of the pumped liquid p by dividing the pressure created pump at a given flow rate, to the current design head H and coefficient g, the calculation of the flow rate when the pump is driven by an asynchronous electric motor is carried out in a similar way, only at first the characteristic of the pump with an asynchronous electric motor Telem is recalculated using the formula:
for flow: Q ₁ / Q ₀ = (n ₁ / n ₀ ) or Q ₁ = Q ₀ (n ₁ / n ₀ );
for pressure:

or

;
for power:

or

,
where Q ₁ , H ₁ , N ₁ , n ₁ - current values of flow, pressure, power, speed of the pump shaft, and Q ₀ , Н ₀ , N ₀ , n ₀ - respectively, their passport values, calculated data for the transmission system are received to a control room in a computer containing the appropriate database, with the help of which all the necessary information on the measurement and analysis of the costs of pumping units is calculated.

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