WO2022245228A1

WO2022245228A1 - System for measuring temperature distribution in heating network and method of monitoring heating network

Info

Publication number: WO2022245228A1
Application number: PCT/PL2021/050032
Authority: WO
Inventors: Wojciech CHMIELORZ; Marcin BARCZYK; Pawel JELEN; Artur BOSEK
Original assignee: Bpe Sp. Z O.O.
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2022-11-24

Abstract

The present invention relates to a system for measuring the temperature distribution in a heating network, enabling indirect monitoring of also other parameters of the heating system, such as potential pipeline leakage, or detection of sections of the heating network, where the medium flowing through the pipeline loses heat to a different extent than expected/designed. The invention also relates to the method of using the system according to the invention in the process of monitoring a heating system by modifying the method of presenting the heat flow as well as signaling potential anomalies in the operation of heating networks and detecting their failure.

Description

System for measuring temperature distribution in heating network and method of monitoring heating network

European patent application EP2074414B1 describes systems and methods of pipeline dampness detection, using lines of temperature transducers laid along or across the pipeline, measuring the temperature differences at the service pipe and the casing with keeping the minimum distance of the foam between the lines of the transducers. While such a solution allows for obtaining numerous data on the condition of the heating network, it is difficult to apply to the already existing heating networks, because it would require the replacement of virtually all pipelines in the heating network, which in turn is unprofitable and impossible for more complex heating systems. On the other hand, when creating a new district heating network, such a solution is expensive because it requires the development and use of district heating pipes with built-in metering lines, which are more expensive than the currently used district heating pipes.

From the Chinese document CN206258226U, a monitoring system based on a distributed temperature measurement is known. It uses an optical fiber placed on the outer surface of an insulating pipe, where the temperature is measured by observing changes in the ambient temperature. This system does not have the ability to detect local moisture in the insulation layer, and has low sensitivity for external leakage monitoring.

Another known solution is the monitoring system using resistance measurement: it uses a nickel-chromium alloy wire as the detection line, and the wire has a perforated outer sheath, this method is used to locate leaks and break points. This type of measurement however requires special detection line, which is most often not present in the most common types of pre-insulated pipelines.

Yet another commonly known and used solution is a monitoring system using impedance measurement: two copper wires are installed in the insulation layer of the district heating pipeline and used as the detection line, and the leak point and break point are assessed by measuring the change in loop impedance, so that the leak location can be estimated. Currently, most systems are developed based on this principle and a large proportion of the pre-insulated district heating pipes produced are equipped with two copper wires. Unfortunately, such a system does not allow for distributed temperature measurement.

In view of the above, it is clearly visible that the currently known solutions in the field of heating and cooling network supervision systems are based on wire resistance or impedance measurements, which allow to detect possible damage or dampness to the insulation resulting from incorrect construction of the pipeline, external interference or manufacturing defect, but not enable simultaneous temperature measurement in many places of the heating network. Possible modifications of known solutions in order to enable temperature measurements (e.g. according to the document EP2074414B1 or CN206258226U) require large interference in the heating system, i.e. replacement of the heating network pipes or getting into the existing pipes along their entire length, which is practically impossible. What's more, the currently used leak detection systems from the heating network do not allow for accurate enough determination of the leak location before starting repair work and additional field measurements are necessary to precisely determine where works are necessary and where, for example, a street should be excavated.

The aim of the invention is therefore to provide a system enabling constant supervision over a heating or cooling network, remotely, with the possibility of easy, quick and precise locating of problems/anomalies based on the use of a distributed temperature measurement carried out with high resolution (density of measurement sites), while at the same time maximizing the use of currently commonly used district heating pipes and minimal interference with the surroundings of the district heating pipeline.

Another object of the invention is to provide a method for monitoring a heating network in which, using a distributed temperature measurement, the flow of the heating/cooling medium in the system can visualized in a clear and accessible way, which in turn allows easy detection of anomalies/failures of the heating system, using relatively simple calculation algorithms. The main aim of the invention is achieved by a system for measuring the temperature distribution in a heating network, where the heating network comprises pipelines made of pipes for a heating or cooling medium, the pipes forming pipe sections, where said pipes are equipped with a layer of thermal insulation, where the system is provided with access points located in certain places near the said pipes, where there is at least one electrically conductive wire placed along at least some of the pipe sections, wherein it comprises temperature transducers placed along the at least some of the pipe sections, wherein the system also includes data concentrators that are adapted and configured to collect the data from the temperature transducers, wherein the temperature transducers are connected to one another in a manner that allows for a serial data transmission of a data measured by the temperature transducers, utilizing the at least one electrically conductive wire, wherein each respective data concentrator is arranged to collect the data from the temperature transducers placed along a given pipe section, and to transfer them to a computer system that monitors a given heating network, wherein the temperature transducers of each respective pipe section are powered by their respective power source.

Preferably, there are two electrically conductive wires placed along the at least some of the pipe sections, and the temperature transducers transmit data utilizing said two electrically conductive wires.

Preferably, the two electrically conductive lines are pipeline continuity control lines that are pre-installed in the district heating pipeline insulation.

Preferably, two electrically conductive wires are located outside the thermal insulation of the pipeline.

Preferably, the temperature transducers are located along the at least some of the pipe sections with one such transducer at each of the locations where separate pipes are joined together or where separate pipes are connected to other pieces of equipment, especially such as valves, pumps, pipeline elbows, pipeline tees, pipeline reductions etc. Preferably, the transducers are placed along the pipelines in groups of two.

Preferably, the system is further provided with backup power source based on electro chemical cells.

Preferably, the system is further provided with photovoltaic modules arranged to be able to recharge the electro-chemical cells.

Preferably, one data concentrator is configured to collect temperature transducer data from a pipeline section up to 200 meters long.

Preferably, the data concentrator is directly connected to the computer system via an electrically conductive cable or an optical fiber.

Preferably, the data concentrator is connected to the computer system wirelessly.

Further object of the invention is achieved by a method of monitoring the heating network, where the district heating network comprises pipelines made of pipes for a heating or cooling medium, the pipes forming pipe sections, where said pipes are equipped with a layer of thermal insulation, where access points are located in certain places near the said pipes, where at two electrically conductive wires are placed along the individual pipe sections, where temperature transducers are located along the heating pipes, where the temperature transducers are connected to two electrically conductive wires, and connected to one another in a manner that allows for a serial data transmission of a data measured by the temperature transducers, utilizing the two electrically conductive wires, where the temperature transducers are also powered via said two electrically conductive wires, where the system also includes data concentrators that are connected to two electrically conductive wires of the given pipe sections, where data concentrators are adapted and configured to collect measurement results from temperature transducers through two electrically conductive wires and transfer them to a computer system monitoring a given heating network where, with the use of data concentrators, measurement data from temperature transducers is collected and sent to the computer system, where the computer system processes the collected data relating to the measured temperature, using the design and operating parameters of the heating network, and provides a user, via a user interface, with information relating to temperature distribution in the heating network and on possible detected anomalies in the operation of the heating network, in particular on leakages in pipelines, localized sections of the heating network about excessive heat loss, etc.

The system according to the invention is easy to use, because the assembly of the system elements is not complicated and does not significantly affect the construction of the pipeline itself, as well as the elements of the system according to the invention can be connected to the existing heating networks during service/repair works of the operating network, when making new outlets, etc. The temperature transducer can be mounted on any fragment of an insulated fragment of the pipeline (e.g. on fragments of a muff, which are delivered uninsulated) with a dedicated band. The temperature transducer is connected to the system (i.e. it is connected to the two-wire line already present in the pipeline) in the same way as the network control connections used so far. Each element has its own individual and unique address enabling unambiguous reading of data from the transducer and there are practically no restrictions on the number of measured points and their installation. The simplicity of the solution does not affect the operation of the pipeline, does not require its modification or interference with the infrastructure. The system is designed for all types of heating or cooling networks, from low to high parameters, with the use of different types of pipelines. The presented solution increases the possibilities of the heating or cooling network administrator in the field of obtaining data on the network operation, such as: fault detection, flow analysis, heat losses, etc. As a result, it significantly improves the functionality of the system and contributes to the reduction of operating costs.

Additional advantages of the developed solution are the ease of installation and relatively low cost of implementation.

Numeral references:

1 - heating pipeline

2 - temperature transducers

3 - bands

4 - electrically conductive double wire

5, 5A - two-wire cable line

6 -thermal insulation

7 - data concentrator

8 - heating chamber/access point The system according to the invention is schematically shown in Fig. 1, showing a fragment of a pre-insulated heating pipeline 1, on which temperature transducers 2 are mounted with the use of dedicated bands 3. Temperature transducers 2 include temperature sensors, e.g. thermocouples, and basic electronic elements that allow to convert electrical signal from the sensors into digitalized electrical signal, that is convenient to transmit to further devices.

Temperature transducers 2, preferably with the use of dedicated bands 3, can be mounted on any fragment of a pre-insulated heating pipeline 1 with a distance between each other ranging from 10-20 cm up to several-dozens of meters. Preferably, the transducers 2 are mounted within the system at each junction point between the pipes and also between the pipes with other typical equipment for a heating system, such as pumps, valves, pipeline elbows, pipeline tees, pipeline reductions etc. to allow for a cost-effective resolution of the measurements of the pipelines.

In some embodiments the temperature transducers 2 are equipped with a double wire 4 for connection to a two-wire cable line 5 running along the pre-insulated heating pipeline 1. As a two-wire cable line 5, cables for pipeline continuity control that are pre-installed in the insulation 6 of the heating pipeline 1 are usually used. Such configurations allow for retrofitting of the already existing heating systems in a relatively simple manner -just by adding the transducers 2 and connecting them to the already present wires 5.

The two-wire cable line 5 acts as a serial data transmission bus with power supply. It connects all temperature transducers 2 placed on a given section of a pre-insulated heating pipeline 1 with a data concentrator 7 built in a well or a heating chamber 8, which is an element of the heating network infrastructure.

In other embodiments, where there is only a single electrical wire running along the pipes, the transducers 2 may be attached with said single wire and also to the pipe itself -as due to low operating voltages and currents of the transducers 2, the pipes themselves can serve as the second electrically conductive wire.

In yet another embodiment, the pipes may be of an older type, which is not provided with any electrical wires 5 running within its' thermal insulation - in such cases said electrically conductive wires (or at least a single one - when the pipe would serve as a second one) could be added to the pipes while also attaching transducers 2 to the pipes - for this purpose, an additional cable line 5A led outside the heating pipeline insulation 1, may be used. With respect to the electrically conductive wires, in a single thermal insulation there can be provided a single pipe or two or even more pipes, and with that - more than two electrically conductive wires - but preferably the system according to the invention utilizes at least one electrically conductive wire, preferably made of copper, aluminum or NiCr.

In yet other embodiments, the transducers 2 convert the measured temperature to optical signals and transmit their data via an optical fiber cable, serving as a serial data transmission bus. In such embodiments, the system is provided along the pipes with at least such an optical fiber cable and means for supplying power to the transducers 2, preferably in form of at least one electrically conductive wire, more preferably - in form of the two electrically conductive wires 5, 5A.

The data concentrator 7 converts the data transmission signal from individual temperature transducers 2 into a standard data transmission protocol (e.g. Ethernet, Profibus, Modbus, etc.), which enables connection with a wire, fiber optic or wirelessly (by Wi-Fi, Bluetooth, 3G, 4G, 5G network or by other types of radio waves) with the data analysis and archiving system in form of a computer system.

The system can be further modified to be more long-lasting, by providing two temperature transducers 2 at each measurement point along the pipelines 1. In such embodiments in case of a failure of one of the transducers 2 -the system would not require immediate service action to maintain its' operability and precision of measurements.

While in most of the embodiments, the system is powered using normal connection to the power grid, it might be also equipped with backup power sources, e.g. for maintaining operability of the system according to the invention in case of a loss of power in the grid. For this purpose, electro chemical cells might be added, preferably in the vicinity of the data concentrators 7. Furthermore, to also allow for a more environmental-friendly power source, such electro-chemical cells could be further attached to photovoltaic modules, that would charge them during daytime and reduce consumption of power from the grid.

Also, the transducers 2 themselves may be connected so that the power is delivered to them in series, parallel or with a mixed series/parallel connection. Flowever, regardless of how the power would be delivered to the transducers 2 - data transmission from the transducers 2 to their respective data concentrators 7 should be realized in series, such that the system would not be equipped with unnecessary wires.

Considering technical aspects of the data transmission from the transducers 2 using electrically conductive wires 5, 5A, it would be preferable for the system to join a single data concentrator 7 and transducers 2 from not too long part of the pipeline 1. In many embodiments it would be thus desirable to configure the system in such a way, that a single data concentrator 7 would collect the data from the transducers 2 located not further than 200m from the data concentrator 7 - which is thus a preferable length of a single pipe section. In other embodiments where optical fiber cable would be used for a data transmission - this preferable length limitation would not apply.

Considering connectivity of the data concentrators 7 with a computer system that would be responsible for collecting and processing the measurements from the transducers 2 - it can be done using a wired connection (electrically or via optical fiber cable), ensuring more reliability and security of the data transfer, or wirelessly -allowing for reducing the costs (no further wires would be needed).

The above-described system can be duplicated for each fragment of the heating network and the data obtained in this way are analyzed in a computer system for the purposes of monitoring and presenting heat flow to the operators, as well as signaling potential anomalies in the operation of heating networks and detecting their failures.

Claims

1. A system for measuring the temperature distribution in a heating network, where the heating network comprises pipelines (1) made of pipes for a heating or cooling medium, the pipes forming pipe sections, where said pipes are equipped with a layer of thermal insulation (6), where the system is provided with access points located in certain places near the said pipes, where there is at least one electrically conductive wire placed along at least some of the pipe sections, characterized in that it comprises temperature transducers (2) placed along the at least some of the pipe sections, wherein the system also includes data concentrators (7) that are adapted and configured to collect the data from the temperature transducers (2), wherein the temperature transducers (2) are connected to one another in a manner that allows for a serial data transmission of a data measured by the temperature transducers (2), utilizing the at least one electrically conductive wire, wherein each respective data concentrator (7) is arranged to collect the data from the temperature transducers (2) placed along a given pipe section, and to transfer them to a computer system that monitors a given heating network, wherein the temperature transducers (2) of each respective pipe section are powered by their respective power source.

2. System according to claim 1, wherein there are two electrically conductive wires (5, 5A) placed along the at least some of the pipe sections, and the temperature transducers (2) transmit data utilizing said two electrically conductive wires (5, 5A).

3. System according to claim 2, wherein the two electrically conductive wires (5) are pipeline continuity control lines (5) that are pre-installed in the district heating pipeline (1) insulation (6).

4. System according to claim 2, wherein two electrically conductive wires (5A) are located outside the thermal insulation (6) of the pipeline (1).

5. System according to claim 2, 3 or 4 in which the temperature transducers (2) are located along the at least some of the pipe sections with one such transducer (P2) at each of the locations where separate pipes are joined together and/or where separate pipes are connected to other pieces of equipment, especially such as valves, pumps, pipeline elbows, pipeline tees, pipeline reductions etc.

6. System according to claim 5 in which the transducers (2) are placed along the pipelines (1) in groups of two.

7. System according to claim 5 or 6, wherein the system is further provided with backup power source based on electro-chemical cells.

8. System according to claim 7, wherein the system is further provided with photovoltaic modules arranged to be able to recharge the electro-chemical cells.

9. System according to claim 5, 6, 7 or 8 wherein one data concentrator (7) is configured to collect temperature transducer (2) data from a pipeline section up to 200 meters long.

10. System according to claim 5, 6, 7, 8 or 9 wherein the data concentrator (7) is directly connected to the computer system via an electrically conductive cable or an optical fiber.

11. System according to claim 5, 6, 7, 8, 9 or 10 wherein the data concentrator (7) is connected to the computer system wirelessly.

12. Method of monitoring the heating network, where the district heating network comprises pipelines (1) made of pipes for a heating or cooling medium, the pipes forming pipe sections, where said pipes are equipped with a layer of thermal insulation (6), where access points are located in certain places near the said pipes, where two electrically conductive wires (5, 5A) are placed along the individual pipe sections, where temperature transducers (2) are located along the heating pipes, where the temperature transducers (2) are connected to two electrically conductive wires (5,

5A), and connected to one another in a manner that allows for a serial data transmission of a data measured by the temperature transducers (2), utilizing the two electrically conductive wires (5, 5A), where the temperature transducers (2) are also powered via said two electrically conductive wires (5, 5A), where the system also includes data concentrators (7) that are connected to two electrically conductive wires (5, 5A) of the given pipe sections, where data concentrators (7) are adapted and configured to collect measurement results from temperature transducers (2) through two electrically conductive wires (5, 5A) and transfer them to a computer system monitoring a given heating network where, with the use of data concentrators (7), measurement data from temperature transducers (2) is collected and sent to the computer system, where the computer system processes the collected data relating to the measured temperature, using the design and operating parameters of the heating network, and provides a user, via a user interface, with information relating to temperature distribution in the heating network and on possible detected anomalies in the operation of the heating network, in particular on leakages in pipelines (1), local sections of the heating network with excessive heat loss, etc.