Field of invention

The present invention relates to a method for controlling a water distribution system. The present invention also relates to a water distribution system comprising differential pressure sensors.

Prior art

Liquid supply networks providing water and heating are integrated parts of modern cities. Especially district heating has become commonplace in modern times. However, as the liquid supply network is expanded upon as a city expands, a higher pressure is needed to ensure that the pressure is maintained even in the outskirts of the supply network.

However, prior art supply networks are overly conservative by applying a much higher pressure than needed. While some systems have sensors for measuring the pressure, these are often placed in a wired connection with the originally built structure and therefore do not give an accurate reading of the pressure in the outskirts of the supply lines.

Thus, prior art liquid supply networks can be more energy and costefficient by improving the pressure settings.

A method introduced in recent years is an Internet of Things (loT) approach wherein smart sensors are placed in the buildings in the network.

While these technologies allow for a large data gathering and optimization hereof, the high implementation cost is a disadvantage, as the majority of buildings connected to the piping infrastructures need to be monitored in order to get sufficient and precise data.

Thus, it is an object for the invention to provide a method and a liquid supply network which enables better and more accurate pressure control while having a low implementation cost.

EP247607 Al discloses a liquid supply network comprising multiple sensors placed in so-called critical points, wherein said critical points respond to the expected lowest value, using this data from these critical points. While this liquid supply network provides low implementation cost, an alternative that provides more accurate pressure control and more flexibility is desired.

Summary of the invention

The object of the present invention can be achieved by a method as defined in claim 1 and a liquid supply network as defined in claim 9. Preferred embodiments are defined in the dependent subclaims, explained in the following description and illustrated in the accompanying drawings.

The object of the invention can be obtained by a method for altering the pressure of a liquid supply network, wherein the liquid supply network comprises a central plant, wherein the central plant acts as the central location in the liquid supply network, wherein liquid is pumped from the central plant to a desired location within the liquid supply network, wherein the liquid supply network comprises a central control unit, a main pumping unit, and a plurality of supply pipes and booster pumping units connected to the supply pipes, wherein the supply pipes are connected to the central plant, wherein the central control unit is arranged to regulate the pressure of the liquid that is distributed within the liquid supply network by providing instruction to the main pumping units and booster pumping unit, wherein the method comprises the following steps: locating the main pumping unit and the booster pumping units; for the main pumping unit the booster pumping units measuring a pressure value, at a local Maximum Pressure Point, wherein said Maximum Pressure Point for is placed after the outlet of the main pumping unit , for each booster pumping units measuring a pressure value at an Index Point, wherein each Index Point corresponds to a location in the pipeline, in which the lowest pressure can be measured, transmitting the measured pressure values to an adjustment unit, wherein the adjustment unit is configured to provide an adjustment signal to the central control unit, wherein the adjustment signal is provided on the basis of a predefined criterion, wherein the predefined criterion is based on an aimed pressure value, a security maximum pressure value and a security minimum pressure value and adjusting the speed of the main pumping unit and the booster pumping units on the basis of the adjustment signal.

Hereby, a method that allows for accurate regulation of the pressure without a high implementation cost can be obtained.

By the term "liquid supply network" is meant any system that supplies liquid from one or more central locations to another location within a connected network. In an embodiment, the liquid supply network is a water distribution system, in which water is transported from a central plant to buildings. In an embodiment, the liquid supply network is a district heating system, in which a heated brine solution is transported to buildings to keep them heated.

The main pumping unit may comprise a pump assembly comprising several pumps. The step of "locating the main pumping unit and the booster pumping units" can be performed by using a map of the piping structure. It is generally considered trivial for a person skilled to locate the pumping units. The local Maximum Pressure Point will most often correspond directly to the point right after the outlet of the main pumping unit.

The concept of an Index Point is explained in detail under the section "Detailed description of the invention", as the lowest pressure point de- pends on multiple factors.

In a standard liquid supply network, it is expected that a change caused by adjusting the pumps can be registered within 10 seconds, and even for larger systems within less than 1 minute. The pumping units of the liquid supply network can be operated while receiving data from the pressure sensors. The liquid supply network is able to alternate pressure in real-time. Each of the terms "aimed pressure value", "security maximum pressure value" and "security minimum pressure value" are to be understood as not literal pressure values but a corresponding value that a computer can relate to. Said value can be a minimum speed of a pump that would correlate to a certain pressure in the pipeline.

It is to be understood that the step "adjusting the speed of the main pumping unit and the booster pumping units on the basis of the adjustment signal" can be carried out in different ways. In an embodiment, the speed of the main pumping unit and booster pumping units is adjusted by using a control box, wherein said control box is a computer unit that can be used to control the central control unit in the supply network.

By keeping the adjustment signal within a certain pre-set range of values of different pressure, reaching critical pressure levels can be avoided. If more than one pressure sensor is used, the control unit would send an adjustment signal on the basis of the average value measured by the pressure sensors. Accordingly, if one pressure sensor provides no measurement or no change, the pumps will not keep increasing pressure due to an error.

In an embodiment, the adjustment signal is required to maintained within predefined ranges in such a manner that application of the adjustment signal cannot cause the pumping units to reduce the pressure below a predefined minimum level or increase the pressure above a predefined maximum level. When the aimed pressure value has been reached and has remained stable for a predetermined period, no adjustment signal is sent until a deviation from the aimed pressure value is registered.

In general, it is expected in a routine setting that there will be longer periods, in which no adjustments are needed. In an embodiment, the predefined criterion is defined in the central control unit. In an embodiment, the predefined criterion is based on values defined in the central control unit.

In an embodiment, adjustment of the speed of the pumps is carried out on the basis of real time pressure measurements delivered from the central control box to "sky" and "API" (Application Programming Interface) to the SCADA- system. (Supervisory Control And Data Acquisition). The SCADA-system is controlling the pump speed by data delivered from the control box. SCADA is the control system term for district heating and water supply network. For buildings, the HVAC (Heating, ventilation, and air conditioning) control system term is BMS (Building Management System). The pump speed is adjusted by the SCADA or the BMS system.

It is possible to adjust the pump speed without SCADA and BMS. In that case will a second control box run as a receiver. The secondary control box has output for direct pump speed control. In an embodiment, the predefined criterion is continuously updated and sent by the sensors. In an embodiment, the system allows a 0.1 bar deviation from the aimed value prior to adjusting the signal.

Having a lowered pressure in a supply network provides several benefits. Especially, in older systems with an older piping structure small leakages can be a problem. By reducing the pressure, it is possible to reduce the overall usage (m ³ of liquid) in the systems, both through less leakage and in general. In central heating systems the difference in temperate (cooling) has a reciprocal relationship with overall usage (m ³ of water), and a better cooling is obtained when the overall usage is lowered. Thus, it is possible to improve the overall energy efficiency of the system.

In an embodiment, the method comprises the following steps:

- locating one or more branching points;

- measuring a flow value at the one or more branching points and

- recording the flow values on a computer-based medium.

Hereby it is possible to obtain flow data for the liquid distribution network.

In an embodiment, the liquid supply network is a district heating system in which differential pressure is measured.

In an embodiment, the method comprises the steps of selecting one or more bypasses as a location for measuring pressure and selecting the one or more bypasses as the Index Point.

In an embodiment, the measurement of pressure in each of the bypasses are performed by at least one differential pressure sensor, wherein the differential pressure sensor comprises a temperature sensor configured to measure one or more temperature values, wherein the pressure sensor is configured to directly or indirectly (e.g. via a gateway) wirelessly transmit the detected measurements to the adjustment unit, wherein the adjustment unit is configured to transmit an adjustment signal to the central control unit, wherein the adjustment signal is provided on the basis of at least one predefined criterion, including predefined ranges of: an aimed pressure value, a security maximum value and a security minimum value and an aimed temperature value, a security maximum temperature value and a security minimum temperature value. In an embodiment, the method comprises the step of locally altering the pressure valves located in the bypasses based on a communication between the central control unit and the pressure sensor.

In an embodiment, the method comprises the steps of: locating one or more branching points; selecting one or more branching points as location for measuring pressure and selecting one or more branching points as Index Point.

In an embodiment, the adjustment unit performs a security check after sending the adjustment signal the second time to avoid a negative feedback loop. By the term "security check" is meant an action that has the purpose of ensuring that certain restriction criterion is fulfilled.

As an example, the system can delay sending another signal until the central control unit has obtained data from at least a minimum number of sensors, e.g. four. Hereby, it is possible to ensure that a negative feedback loop occurs if a sensor is faulty and therefore does not register any pressure change.

In an embodiment, the adjustment signal will contain instructions for the control unit to give an alarm in case that the security check shows that a measured value is outside the security criterion range.

In an embodiment, wherein the differential pressure sensor comprises an integrated or external temperature sensor that is configured to measure one or more temperature values. In an embodiment, the pressure sensor is configured to directly or indirectly (e.g. via a gateway) wirelessly transmit the detected measurements to the adjustment unit.

In an embodiment, the adjustment unit is configured to transmit an adjustment signal to the central control unit, wherein the adjustment signal is provided basis of a predefined criterion, including predefined ranges of an aimed pressure value and/or a security maximum value and/or a security minimum value and/or an aimed temperature value, a security maximum temperature value and/or a security minimum temperature value, wherein a flow measurement is performed by a flow sensor, wherein said flow measurement is wirelessly transmitted along with the pressure and temperature values.

The liquid supply network according to the invention is a liquid supply network comprising a central plant, comprising a central control unit, a main pumping unit, and a plurality of supply pipes and booster pumping units connected to the supply pipes, wherein the supply pipes are connected and branch off from the central plant, wherein the central control unit is arranged to regulate the pressure of the water that is distributed in the liquid supply network by providing instruction to the main pumping unit and booster pumping units, wherein the liquid supply network further comprises one or more pressure sensors installed in selected locations in the supply pipes, wherein the selected locations correspond to a Maximum Pressure Point and Index Point in the supply pipes, wherein the pressure sensors are configured to measure and wirelessly transmit the measured pressure values to an adjustment unit, wherein the adjustment unit is arranged and configured to send an adjustment signal to the central control unit, wherein the adjustment signal is based on an aimed pressure value, a security maximum pressure value and a security minimum pressure value.

In an embodiment, the liquid supply network comprises one or more flow sensors configured to measure flow in a branching point. In an embodiment, the liquid supply network is a district heating system, wherein the pressure sensors are differential sensors. In a district heating system, the central plant is a central heating plant. In an embodiment, the differential pressure sensors are powered by an energy harvester.

In an embodiment, the differential pressure sensors comprise an inter- nal or external sensor assembly, wherein the sensor assembly is configured to measure temperature and to be mounted and operated in a bypass. In an embodiment, the sensor assembly also comprises an actuator arranged and configured to regulate the local pressure.

In an embodiment, the adjustment unit is arranged and configured to receive data from the sensor assembly, wherein the adjustment signal is further based on an aimed temperature value, a security maximum temperature value and a security minimum temperature value.

In an embodiment, the sensor assembly comprises an element designed for performing a security check.

Flow data can be utilized by skilled personal to determine leakage in the pipes in the network by comparing the measured flow at the branching point and the flow at the heat meters in the following pipe circuit after the branching point. The flow can be measured by traditional ways like ultrasound and Axial Turbine meters, but also as a differential pressure flow meter where the flow is calculated by the principles of Bernoulli equation.

In an embodiment, the method comprises the steps of locate one or more branching points; selecting one or more branching points as a location for measuring pressure and selecting one or more branching points as the index point.

Hereby, it is possible to provide an easy alternative to locating suitable measurements points for measuring the pressure.

In an embodiment, the method comprises that the measurement of pressure in the branching are performed by differential pressure sensors, wherein the differential pressure sensors are built together with a temperature sensor that are configured to measure and wirelessly transmit one or more measured temperature values to the adjustment unit, wherein the adjustment unit is configured to transmit an adjustment signal to the central control unit, wherein the adjustment signal is provided based on a predefined criterion, wherein the predefined criterion are based on an aimed pressure value, a security maximum value and a security minimum value and an aimed temperature value, a security maximum temperature value and a security minimum temperature value, and wherein further a flow measurement is performed by a flow sensor, and wherein said flow measurement is wirelessly transmitted along the pressure and temperature values, wherein said flow value is recorded on a computer-based medium.

Hereby, skilled personal can obtained information about flow, temperature and pressure which can allow for calculation of energy spent in the system.

When the volumetric mass and the specific heat capacity of the medium is known, then it is possible to calculate the power by measuring the flow and temperature.

P=q x p x e x AT [W]

P Power at the flow point in Watt

Q flow [m ³ /s] p (Rho) Volumetric mass density of the medium. Water is 1000 [kg/m3]

C specific heat capacity of water. Without anti-freeze 4190

[J/kgK]

AT difference between the flow and return temperature [K]

In an embodiment, the liquid distribution network further comprises one or more flow sensors configured to measure flow in a branching point.

In an embodiment, the district heating system further comprises a comprises one or more flow sensors configured to measure flow in a branching point. By the term "branching point" is meant a point wherein the pipes lines branch off from the main pipeline. Depending on pipe infrastructure this can be arranged in different ways.

The branching point in a district heating system is typically located in a well with two valves. One vale for flow(inlet) pipe and one valve for the return pipe. By knowing the flow, pressure, and temperature, it is possible to calculate the accurate power at the branching point. Further will those data help to an extended supervision of the entire district heating system. A branching point can be located either off to a city section or to a specific road depending on the infrastructure of the liquid supply network.

Description of the Drawings

The invention will become more fully understood from the detailed description given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:

Fig. 1 shows a schematic view of a prior art system;

Fig. 2 shows a schematic view of a liquid supply network with pumps and an index point marked;

Fig. 3 shows a schematic view of a city section with a bypass;

Fig. 4 shows a flowchart of the method according to the invention;

Fig. 5 shows a schematic view of the fourth to seventh step of the method as shown in Fig. 4;

Fig. 6 shows something a schematic view of the fourth to seventh steps of the method as shown in Fig. 4 and

Fig. 7 shows a schematic view of a city section with a branching point.

Detailed description of the invention

The invention will become more fully understood from the detailed de- scription given herein below. The accompanying drawings are given by way of illustration only, and thus, they are not limitative of the present invention. In the accompanying drawings:

Fig. 1 illustrates a schematic overview of a prior art liquid supply network 2. A typical liquid supply network 2 comprises a central plant 4 connected to buildings through a pipe network 10. In Fig. 1, the triangles represent pressure measurement points 14. Both measurement points 14 are wired to the central plant 4. However, the pipeline 10 extends beyond the measurement's points 14.

The stripped lines represent future building areas that will be built as the city further expands. The prior art system suffers from the drawback that it is difficult to optimise the pressure applied in the network 2.

Prior art systems are in general operated in a manner, in which the pressure applied is sufficiently high to ensure that the local pressure in outer areas is maintained above a predefined level. The reason for this is that the customers are satisfied and therefore do not send in complaints. In a typical liquid system, multiple pumps are used, instead of just a central pump. Accordingly, a typical liquid system comprises a main pumping unit that comprises several pumps.

Fig. 2 illustrates a liquid supply network 2 comprising a main pumping unit 8 and several booster pumping units 12. The network 2 comprises a single centrally arranged main pumping unit 8. The network 2 further comprises a plurality of booster pumping units 12 arranged in several different location within the liquid supply network 2. It is important to underline that the main pumping unit 8 can and typically will comprise several pumps. In an embodiment, the main pumping unit 8 comprises several pumps. In an embodiment, the main pumping unit 8 comprises a single pump only.

The central plant 4 is centrally arranged in liquid supply network 2. The central plant 4 typically comprises a control central configured to control the entire liquid supply network 2. The central plant 4 comprises the main pumping unit 8.

To ensure that the main pumping unit 8 is set at an appropriate level of speed (typically within a predefined range), two pressure measurements locations are selected. A first pressure measurements is carried out right after the outlet of the main pumping unit 8, in such a manner that maximum pressure is measured. Accordingly, the location of the first pressure measurement is defined as a Maximum Pressure Point (MPP).

A second pressure measurements is carried out in a location defined as an Index Point (IP). The Index Point corresponds to the location wherein the lowest pressure can be measured. It is important to note that locating the location of the Index Point is not a straightforward matter. In a water distribution system, the Index Point IP is defined by two factors, the pipe length and the altitude. As a rule of thumb, a long pipe length in combination with a high-altitude A would result in a low pressure. However, due to the layout of the piping structure, the selection of an Index Point requires considerations. The index point is selected by finding the point with the highest loss of pressure 4F. In water distribution systems water is moved from an area of high pressure to lower pressure. The pressure difference between the high pressure and low pressure point is the pressure difference needed to move a specific amount of water, the relationship is described by: wherein qi, q ₂ is the amount of water [m ³ /s] and Pi, P ₂ is pressure [Pa].

The amount of energy needed to transfer (distribute) water to its desired location by moving a pump is given by:

Powerpump [W] =AP-q where q is the flow [m ³ /s] and AP is pressure [Pa]. The required pressure is found by calculating the pressure drop in the pipeline and components such as vents that the water is distributed to.

For a straight pipeline, the loss of pressure during transport can be calculated by using the following formula:

Wherein:

1 is the friction coefficient.

P is the density of water [kg/m ³ ]. is the median transfer speed of water [m/s] is the pipe length [m] is the internal diameter of the pipes [m]

In a simplified case pipe length is the main determining factor determining where the latest loss of pressure will occur.

In case the liquid transport network is a district heating system, the setup is similar to that of a water distribution system. The major difference is that the piping system has a recycling mechanism built in such that the heated water from the central plant is pumped back to the central plant after use. To ensure that the backflow is regulated properly bypasses are placed at the ends of the line to ensure a continuous process. Furthermore, differential pressure is measured instead of static pressure. In an embodiment the sensor comprises an additional sensor unit arranged and configured to measure static pressure.

The Index Point is selected based on the pipe diameter and length. The information can be found in GIS (Geographical Information System) Maps. In order to ensure that the booster pumps 12 are at the correct level, the same setup with two measurements points is selected. It is also important to note that if the pipelines move through a housing area, there will be a pressure drop and as such, it is better to measure prior to the pipe going to the housing area and get the relative lowest value instead.

During operation it is advantageous if control rounds are made in order to ensure that the Index Point is selected correctly. Thus, by using a map and information related to pipe infrastructure, a skilled person can calculate the Index Point. The diamond symbol 20 indicates a schematic point wherein an Index Point could be placed for the booster pumping unit 12 arranged closest to it.

By correlating with the Maximum Pressure Point and the Index Point maximum and minimum threshold values are chosen, such that the pressure is not too high. Nor should the pressure be too low, as this will have a negative effect for user of the system. Furthermore, the booster pumping units 12 that are arranged to increase speed in the pipelines further away from the central pumping unit 8 (in terms of pipe length) would need to overcompensate for the decrease in pressure, which could lead to an overall loss of efficiency. Static pressure sensors that can wirelessly transmit data back to an adjustment unit are placed at the measurement points.

The adjustment unit can either independently or through contact with the central control system adjust the speed of the central pumping unit 8 and the booster pumping units 12 based on the measured pressure values from the Maximum Pressure Points and Index Points and a set goal value (a predefined level).

In a district heating system, the setup is similar to that of a water distribution system. The major difference between a district heating system and a water distribution system, is that in a district heating system the piping system applies an integrated recycling mechanism configured to ensure that the heated water from the central plant is pumped back to the central plant after use. To ensure that the backflow is regulated properly, the bypasses are placed at the ends of the line to ensure a continuous process. Furthermore, differential pressure is measured instead of static pressure. In an embodiment the pressure sensor comprises an additional sensor unit arranged and configured to measure static pressure.

The Index Point is selected on the basis of the pipe diameter and length. The information can be found in GIS (Geographical Information System) Maps. During operation it is an advantage to control that the Index Point is selected in a correct manner.

Fig. 3 illustrates a schematic view of a city comprises a first section that city comprises a bypass 18. A booster pumping unit 12 is placed in a second section of the city, wherein the second section is located prior to the first section of the city.

It is common for some city sections, especially those further away from the central plant, to have bypasses 18. Bypasses 18 are used to ensure a continuous flow, even in periods of low activity. The location of a bypass would typically also be a useful location to place a sensor for measurements of the Index Point 20. While a bypass 18 will not always be located in the position, in which the lowest possible pressure is present, bypass 18 will typically be located in a location, in which it is easy and convenient to mount a sensor assembly 16.

As a bypass 18 is used in district heating systems, it is -an advantage to collect temperature information at the bypass 18. In this manner, it is possible to regulate that the temperature at the bypass 18. This can be done by using a sensor assembly 16 that is located in the bypass 18, wherein the sensor assembly 16 is configured to measure and transmit detected pressure and temperature values.

Fig. 4 illustrates a flowchart showing the steps of the method according to the invention. In the first step I (for a skilled user) the main pumping unit and the booster pumping units in the liquid supply network are located.

In the second step II, for the main pumping unit 8 a pressure value is measured at the local Maximum Pressure Point. Typically, the local Maximum Pressure Point is located right at the outlet of the main pumping unit. Moreover, in the second step II, for each of the booster pumping units 12 a pressure value 24 is measured at an Index Point 2

The Index Point may be determined by a skilled user. In an embodiment, the Index Point may be determined by using a GIS map. Hereby, it may be possible to determine an optimal point (Index Point). A skilled user, however, will take into consideration the current supply network structure in order to measure at an appropriate location.

In the third step III the measured and collected information is transmitted to an adjustment unit 26. The adjustment unit 26 may be located in a central plant. The transmitted information is sent to the adjustment unit 26 that is configured to provide an adjustment signal to a central control unit. The control unit is configured to control the main pumping unit and the booster pumping units.

In the fourth step IV the adjustment unit 26 provides an adjustment signal 56 to the central control unit.

In the fifth step V the central control unit adjusts the speed of the main pumping unit 8 and the booster pumping units 12 on the basis of the adjustment signal 56.

The specific action taken will depend on the individual system, but it is expected that in the majority of systems the adjustment includes that the central control system adjusts the speed of the individual pumps of the main pumping unit and the booster pumping units. In the sixth step it is checked if the predefined criterion is met.

If the criterion is not met the fourths step IV is repeated. If the criterion is met, the settings will be maintained like indicated in the seventh step VI.

If the criterion is not met, an additional adjustment signal is sent (step IV). In an embodiment, an additional security check step is performed after step IV is performed. If the criterion is met (after a short time), the system awaits a deviation from the aimed value.

In an embodiment, the system allows a 0.1 bar deviation from the aimed value prior to adjusting the signal.

Fig. 5 shows a schematic overview of the fourth step to the seventh step, wherein the measured data come from a pressure sensor. A measurement is carried out at the Index Point 20 and local maximum pressure point 22, wherein the sensor data 24 is transmitted to the adjustment unit 26.

The adjustment unit 26 initiates a calculation 28 carried out on the basis of a predefined criterion. This calculation is represented by a pressure scale 40, wherein a security maximum pressure 32 and a security minimum pressure 30 are represented by bars. The scale 40 shows the registered measurement value 36 (represented by the circle) and its deviation 38 from the aimed pressure value 34 (represented by a star). Based on the calculation, an adjustment signal 56 is generated and sent to the central control unit 42.

Fig. 6 shows a schematic overview of the fourth step to the seventh step, wherein the measured data originate from a temperature sensor. When a temperature is measured, the same procedure is carried out. The major difference is that a sensor assembly 16 is used instead of just a pressure sensor. In an embodiment, a sensor assembly 16 located in a bypass can use this location as the Index Point 20. Similar to the case for a pressure measurement, a temperature scale 44 with security maximum temperature 48 and security minimum temperature 46 is used for the calculation 28. In the same manner as shown in Fig. 6 the deviation of the measured value 54 between the measured temperature value 50 (represented by the square) and the aimed temperature value (represented by the star) is found.

Based on this value, an adjustment signal 56 is sent to the central control unit 42. The calculation 28 can be carried out for both temperature and pressure at the same time. The adjustment signal 56 can contain information relating both to pressure and temperature, if needed.

It is expected that the measured value is within the range between the maximum (32, 48) and minimum value (30, 46). However, if the value is within the range of the minimum or maximum values, a security check is made.

If after the security check, the measured value is the same, the adjustment signal will contain an alert. Accordingly, an operator may be contacted, or an emergency protocol be carried out.

Fig. 7 shows a schematic view of a city section. Branching points 21 of the city section are shown. In general, the size of the branching points 21 can vary. A branching point 21 can be located and configured to control a flow to a city section. In an embodiment, branching point 21 can be located and configured to control a smaller flow for a number of domestic buildings (a neighbourhood) by way of example.

The configuration of the branching points 21 and sensor 15 or sensor assembly depends on whether the liquid supply network is a water distribution system or a district heating system. If the liquid supply network is a water distribution system, the branching points 21 corresponds to a branching of the main pipelines into a cut-off neighbourhood. In an embodiment, the branching point 21 is located in a well that comprises a number of regulation valves arranged to allow for regulation of water to the specific area (cut-off neighbourhood). By placing a flow sensor 15 in the branching point 21, it is possible to collect data for the area and use this data for analysis of e.g., leakage of the pipes. If the liquid supply network is a district heating system, the branching points 21 may be located in a well provided with a number of regulation valves arranged and configured to allow for regulation of water to the specific area (cut-off neighbourhood).

By integrating a flow sensor into the sensor assembly 17 in the branching point 21, it is possible to collect data for the area and use this data for analysis of e.g., energy consumption by also looking at temperature data.

List of reference numerals

2 Liquid supply network

4 Central plant

6 Central control unit

8 Main pumping unit

10 Supply pipes

12 Booster pumping units

14 Pressure sensor

15 Flow sensor

16 Sensor assembly

17 Sensor assembly with flow sensor

18 Bypasses

20 Index Point

21 branching point

22 Maximum Pressure Point

24 Sensor data

26 Adjustment unit

28 Calculation

30 Security minimum pressure value

32 Security maximum pressure value

34 Aimed pressure value

36 Measured pressure value

38 Deviation from the aimed pressure value

40 Pressure scale

42 Control unit

44 Temperature scale

46 Security minimum temperature value

48 Security maximum temperature value

50 Measured temperature value

52 Aimed temperature value

54 Deviation from the aimed temperature value

56 Adjustment signal