DE10025470A1 - Permeability i.e. leakage inspection method for liquid or gas pipelines, involves using manometer for measuring temperature-dependent pressure change of liquid or gas in pipeline - Google Patents

Abstract

A manometer (4) is arranged near the pipeline carrying gas or liquid such as water, and the pressure change of the liquid or gaseous medium in response to the change in temperature, is measured. An independent claim is also included for permeability i.e. leakage inspection device.

Description

The invention relates to a method for checking the permeability of conductors gene with the further features of the preamble of claim 1. The inven also relates to a device for checking the permeability of lines with the further features of the preamble of claim 19.

In general, there is a risk that liquid or gas lines will open up due to contamination in the respective medium flowing in the lines or grow inside for other reasons. So it is z. B. possible with water pipes Lich that lime or other contaminants in the water from the pipes sets and clogs them. This danger also exists with oil or gas pipes, may but cannot be recognized from the outside. The erroneous assumption that a growing management is still consistent, can have different negative consequences and even bring great dangers.

The problem can e.g. B. occur with steam or hot water boilers to which what are connected. With such steam or hot water boilers, e.g. B. Boilers, it is necessary to carry out a water level control, this prevents a drop in the water level below a predetermined minimum level will. Too much a drop in the water level would result in the flame pipe may be exposed, which could have catastrophic consequences.

One way to measure the water level is to measure the differential pressure kes between the lower part of the boiler (water part) and the upper part range of the boiler (steam area). Lines to the respective area are on the outside connected, between which a differential pressure measuring device is connected. The The differential pressure measured essentially corresponds to the hydrostatic pressure  inside the boiler at the point where it connects to the water area Line is arranged. So z. B. on the differential pressure gauge at a vapor pressure of 10 bar and a water pressure in the lower area of the boiler of 10.3 bar To measure a differential pressure of 0.3 bar, which corresponds to the hydrostatic pressure. The water level can therefore be derived on the basis of the measured differential pressure or calculated. It can now happen that due to chemicals, lime or other impurities in the boiler water the pipes leading to the dif lead pressure transducer or measuring device, slowly grow and thereby none reasonable regulation is more possible. A pipe that is no longer continuous on the inside however cannot be recognized from the outside. To check the continuity there is only the possibility, the lines or the differential pressure transducer to dismantle so that the lines z. B. with the help of a suitable conduit lighting can be checked.

The invention has for its object to provide a method with which the check of the permeability of lines is carried out in a simple manner can be.

This object is ge by the characterizing features of claim 1 solves. Advantageous further developments of the method result from the subclaims Chen 2-18.

An advantageous device for performing the method is taught in the device claims 19-36 .

To achieve the object, the invention provides that the permeability the line by changing the volume of one in the Lei liquid or gaseous medium via a dependent one Pressure change is detectable. A pressure sensor is attached to the end of the line closed. The other end of the line to be checked is open or leads into Recording volume. With a continuous line, the heated or cooled can Flow medium freely in the line. However, the line is not or hardly  Consistently, the expansion volume for the medium is as it is heated severely limited so that there is an increase in pressure of the liquid. Conversely, at ei a non-continuous line a cooled medium to a pressure drop. The changing pressure of the medium is expediently from that to the Line arranged pressure sensor detected. Accordingly, one is going through due to the possibility of evading the medium, no or only ge Rings pressure change take place, with little or no pressure on the pressure sensor Pressure change is detected. In the case of a non-continuous line, on the other hand, one measurable pressure change on the pressure transducer. To check the passages liquid of lines, the inventive method in a simple manner without great expense.

The liquid or gaseous medium in the line can change be heated to the volume so that the liquid expands. The Erwär mung can be carried out with simple heating devices and thus represents a less expensive method for changing the volume of the pipe in the pipe medium.

Alternatively, it is also possible that the medium in the line for Change in volume is cooled.

The method is advantageously carried out using a medium, in particular a liquid speed, which has a low compressibility. Little compressible Liquids have the advantage that they heat up even when they are only slightly warmed stretch and with a non-permeable line a strong pressure increase and thus ensure a safe measurement of the fluid pressure.

As a medium z. B. water or oil can be used, which in a water or oil line already exists. It is important to ensure that the respective river liquid is not mixed with gas, which may lead to a distortion of the knife result due to the change in compressibility.  

Appropriately, the medium in the line can be by means of the Lei lines arranged heating tapes or heating coils are heated, the on the Medium transferred heat quantity from the outside in a simple manner or gere can be applied. The heating by means of heating tapes or heating spirals also provides an inexpensive heating method due to the relatively simple structure.

The respective medium can also be by means of a heating element used in the line be heated. It is possible to cumulatively pre-heat the exterior and interior increase so that a uniform heating of the medium is achieved.

In the other variant, in which the medium is cooled, can the cooling takes place accordingly inside and outside the line. The medium is expediently heated or cooled near the Pressure transducer, so that the entire line reliably on its permeability is checked.

In a further variant of the method, the differential pressure between two lines gene can be detected by means of a differential pressure transducer, only the medium of the pipe to be checked experiences a change in temperature. At least that's it End of the line to be checked open or leads to a correspondingly large open volume. The end of the other line is also open or to a reception voucher lumen connected, this line can also by means of the inventive method rens be checked for permeability. This is the case with this process variant continuous checking line, there is no change in the differential pressure, since the heated medium can escape into the receiving volume or into the open and the pressure of the medium does not change. A cooled Me Reduce the volume unhindered volume with a continuous line, so that the Pressure of the medium also does not change. However, if the line has overgrown, can the medium does not expand unhindered in the line in the event of heating, so that there is an increase in pressure, which leads to a change in the differential pressure. The changed differential pressure is finally detected by the pressure sensor, with a  Signal can be given that the line is to be cleaned.

The pressure of the medium can expediently be measured on a pressure measuring device in which the pressure sensor is integrated. The Diffe renzdruckaufnehmer be integrated in a differential pressure measuring device. On the (difference) pressure gauge, the pressure of the medium can be read or sent to a ver tied electronics or software forwarded and evaluated there.

The degree of permeability or growth of the lei can be particularly advantageous on the basis of a pressure-time characteristic, in particular a pressure-time Diagram. A comparison of different pressure-time Diagrams provide information about various factors of the pipe system, e.g. B. Rate of increase depending on the cable diameter.

The method according to the invention can advantageously at defined time intervals repeated, and a statement about the time course of the Zu to keep the lines growing. The procedure can therefore act as an early warning system serve, with which corresponding risks can be avoided.

So that the method can be carried out reliably at defined time intervals the repeated execution of the test procedure take place automatically. In the ver should drive z. B. a secured heat or cold source for temperature change of the medium. This enables reliable monitoring of the growth solution of the lines.

The method can be coupled with an alarm function with particular advantage, which is activated from a certain value of the permeability of the line. Consequently can cause major damage caused by an overgrown pipe which can be reliably prevented.

Additionally or alternatively, it can be provided that from a certain value the permeability of the line, a safety shutdown is activated, so that  The process is capable of avoiding major damage or dangers.

The method according to the invention can be used to check the Permeability of lines are applied to a receiving volume, for. B. are connected to a pipe, a container or a boiler. As a boiler one can Steam or hot water boiler, e.g. B. a shell boiler can be provided. there is a line with the water area provided in the shell boiler and the other line is connected to the steam area located above. The The process will be explained using the example of the shell boiler as follows.

The line provided on the water area is expediently located in the lower part range of the boiler room arranged so that the differential pressure (hydrostati pressure) on an outside of the shell boiler, between the pipes arranged differential pressure transducer can be detected. The respective lines are already filled with water, so that the inventive method simply by can be performed by first heating or cooling the water from the outside becomes. The shell boiler represents the volume in which the heated water can flow when the pipe is permeable. At the differential pressure The changing differential pressure then becomes the subscriber (with an overgrown line) or the constant differential pressure (with a continuous line).

A device according to the invention for checking the permeability of conductors gene is closed at least on one side to a pressure transducer. The print subscriber is used to record the pressure of the medium in the line. Fer A device for changing the temperature of the medium is provided. The Liquid heated or cooled in the line expands with continuous lei tion unhindered in this or contracts, the pressure of the Medium remains constant. However, if the line is blocked or overgrown, that is Expansion volume for the heated medium in the line is very limited, so that a pressure increase at the pressure sensor is achieved. Conversely, one is abge cooled medium detected a pressure drop at the pressure sensor.  

The device is characterized by its simple structure and is due to the can also be easily retrofitted.

A heating device can be provided as a device for changing the temperature hen to heat the medium in the pipe. Alternatively, to A cooling device can also be provided for changing the temperature.

A heating tape or heating coil can be arranged around the line as a heating device be net, which ensures simple and inexpensive heating of the medium becomes.

Additionally or alternatively, a heating element can also be provided in the line, which cher causes a direct heating of the medium.

A differential pressure sensor can be provided as the pressure sensor, which is between two lines is arranged. This way the absolute pressure of the Me diums, but only the increasing or constant differential pressure between measured between the two lines. Are both lines open at the end or arranged on a receiving volume, so both lines can on their permeability be checked.

The pressure or differential pressure sensor can expediently be in one Pressure or differential pressure measuring device can be integrated so that the changing or constant pressure is measurable.

The end of the two lines can also lead to a common receiving volume ren, which as a collecting container for the heated medium in the respective line or serves to equalize the pressure of the cooled medium.

The common receiving volume can expediently be a steam or hot water boiler, e.g. B. be a shell boiler that has a sufficient volume for provides the extensive liquid in the lines.  

The steam boiler, e.g. B. the shell boiler has a water area and egg NEN arranged steam area, with the respective area Line for differential pressure measurement of water and steam area is connected. By simply arranging a heating device, it can already be used the differential pressure measurement also checked the permeability of the respective line become.

Advantageously, a comparison electronics for creating a pressure-time Characteristic for the detection of the degree of permeability of the lines hen, which enables a safe control of the lines.

For automatic checking of the permeability of lines according to defined A control unit can be provided at intervals. Automation makes it easier Carrying out the check at certain intervals.

Furthermore, a pressure evaluation unit can be provided with which the gradual Growth of the lines is controllable.

A safety shutdown and / or an alarm device can serve to raise to prevent damage or dangers in overgrown lines.

The invention is based on advantageous exemplary embodiments in the drawings guren explained in more detail. These show:

Fig. 1 is a schematic representation of an apparatus for checking the permeability of a line;

Fig. 2 is a schematic diagram of a device for checking the permeability of two lines connected to a differential pressure sensor;

Fig. 3 is a schematic representation of a shell boiler with dar arranged on lines for measuring the differential pressure;

Fig. 4 is a time-pressure diagram, as well

Fig. 5 is a schematic representation of a shell boiler according to

Fig. 3 with extended functions.

First, reference is made to FIG. 1. Reference number 1 designates the device in its entirety with which the method for checking the permeability of lines is carried out. The line 2 is completed at the end by means of an acquisition volume 3 . However, it is also possible that the line 2 is simply open and ends outdoors. At the other end of the line, a pressure measuring device 4 is arranged, with which the pressure of the medium in line 2 is measured. A pressure sensor is integrated in the pressure measuring device 4 . To check the permeability of the line 2 , a temperature-dependent change in the volume of the liquid or gaseous medium in the line is carried out. A pressure change dependent thereon is detected by the pressure sensor. To change the volume, the liquid or gaseous medium in the line can be heated so that the medium expands and flows into the receiving volume 3 with a continuous line 2 . As a result of this possibility of evading the medium, the pressure of the medium does not change, or hardly changes, and an approximately constant pressure can be measured on the pressure measuring device 4 before and after the heating of the medium. However, if the line 2 is not continuous, the expansion volume for the medium is limited and there is an increase in pressure that can be measured on the pressure measuring device 4 . However, there is also the possibility that the medium in the line is cooled to change its volume. The medium contracts together, that is, its volume decreases, with a continuous line 2 a Druckaus equal, ie a post-flow of z. B. air takes place on the receiving volume 3 . This pressure equalization option does not change the pressure of the medium and the pressure measuring device 4 measures an approximately constant pressure before and after the cooling of the medium. If the line 2 is not continuous, on the other hand, there is a pressure drop which can be measured on the pressure measuring device 4 .

In the method, a medium, in particular a liquid with a low Compressibility used, in which a slight warming or cooling ensures a sharp increase or decrease in pressure. So as a liquid medium for example, water or oil can be used, which has the advantage that a Water or oil pipe can be checked in a simple manner, since the test flows liquid is already on the line.

The liquid or gaseous medium is heated by means of a heating coil 6 arranged around the line 2 . It is also possible to put 2 heating tapes on line 2 and / or to provide a heating element in line 2 . The heating coil 6 is arranged at one end of the line 2 in the vicinity of the pressure measuring device 4 , so that the entire line 2 is checked for its permeability in a reliable manner.

The method uses a liquid with a low compressibility Det, where even a little warming guarantee a strong increase in pressure continuous For example, water or oil can be used as the liquid.

Fig. 2 shows an alternative structure for performing the method according to the invention. A differential pressure sensor is arranged between two lines 2 , 2 '. The differential pressure sensor is integrated in a differential pressure measuring device 5 . A heating coil 6 , 6 'is arranged around the respective line 2 , 2 ' on both sides of the differential pressure measuring device δ, only the liquid or gaseous medium of the line 2 or 2 'to be checked being heated. On each line 2 , 2 'is a receiving volume on the end 3 , 3 ' is arranged, in which the heated medium, for. B. the heated liquid can flow with a continuous line. To carry out the method, the liquid or gas in the line to be checked (z. B. 2) by means of the heating coil z. B. 6 heated. In the case of a continuous line 2 , the heated medium escapes into the receiving volume 3 , the differential pressure between the two lines 2 , 2 'not changing. However, if the line 2 is no longer continuous, the pressure of the medium heated therein increases and a pressure change occurs which is measured on the differential pressure measuring device 5 and can be read there. The same method can be carried out to check the permeability of the line 2 ', only the liquid or gaseous medium therein being heated by means of the heating coil 6 '. When the medium cools down, the same applies as in the description of FIG. 1.

In the respective methods, it is possible that the degree of permeability or the increase in the lines 2 or 2 'is recorded on the basis of a pressure-time characteristic, in particular a pressure-time diagram. Fig. 4 shows such a pressure-time diagram, where the abscissa represents the time t from the time of heating and the coordinate of the pressure of the medium or p the differential pressure is applied. Three measurement curves are entered in the diagram, the dashed line showing the pressure curve of a completely overgrown line 9 . The solid line represents the measurement result of a partially overgrown line 10. The dash-dotted line, which is parallel to the time axis, illustrates the measurement curve of a continuous line 11 , in which the pressure p remains constant.

A particularly advantageous application of the method is shown in FIG. 3. On egg NEN water boiler 7 or generally a steam or hot water boiler, which has a water and a steam area arranged above it, lines 2 , 2 'are connected to the respective area for differential pressure measurement of the water and steam areas. The two lines 2 , 2 'are coupled outside the large water space boiler 7 to a differential pressure sensor which is integrated in a differential pressure measuring device 5 . The line 2 'connected to the water area is arranged in the lower area of the shell boiler 7 , so that the hydrostatic pressure of the water is detected as a differential pressure and thus the water level in the shell boiler 7 can be concluded. If the water level changes, the hydrostatic pressure of the water changes and thus the measured differential pressure. Shut-off valves 8 are attached to the lines 2 , 2 ', for example for repair measures. To check the permeability of the lines 2 , 2 ' 5 heating coils 6 , 6 ' are arranged on both sides of the differential pressure device. The method according to the invention for checking the permeability of the lines 2 , 2 'is now carried out in accordance with the description of FIG. 2, but a common liquid holding container is provided for the two lines 2 , 2 '. The liquid receptacle is the shell boiler 7 . To check the line 2 'connected to the water area, this line, which is already filled with water, must be heated by means of the heating coil 6 '. With continuous line 2 'the water expands into the shell boiler 7 and there is little or no change in the differential pressure. The same applies to checking the line 2 connected to the steam area. With the aid of the method according to the invention, it is thus possible to check the permeability of the lines 2 , 2 'arranged on the large-capacity boiler or a steam or hot water boiler for differential pressure measurement in a simple manner, without dismantling them.

On the respective device, a (not shown in the drawing figures) Comparison electronics can be provided to create a pressure-time characteristic, which measures the degree of permeability of the lines.

The respective method for checking the permeability of the lines can be carried out at defined intervals so that a statement can be made about the temporal increase in the lines. This method expediently takes place automatically, for which purpose a control device 12 is provided (cf. FIG. 4). In addition, a pressure evaluation unit 13 is arranged on the device according to FIG. 4, with which a good control of the time course of the growth of the lines and of the individual measurement is possible. An alarm device 14 turns on at a certain growth rate or a certain degree of growth. The alarm device 14 and / or the pressure evaluation unit 13 can be coupled to a safety shutdown (not shown in the drawing), so that damage or dangers due to an overgrown line can be reliably avoided.

The invention provides a simple but equally effective method Check the permeability of lines.  

Reference list

1

contraption

2

management

2

' Management

3rd

Recording volume

3rd

'' Volume

4

Pressure gauge

5

Differential pressure measuring device

6

Heating coil

6

'' Heating coil

7

Shell boiler

8th

Shut-off valve

9

completely overgrown line

10th

partially overgrown line

11

continuous line

12th

Control unit

13

Pressure evaluation unit

14

Alarm device

Claims (36)

1. A method for checking the permeability of lines, the line being closed at least on one side to a pressure transducer, characterized in that the permeability of the line can be detected by a temperature-dependent change in the volume of a liquid or gaseous medium in the line via a pressure change dependent thereon . 2. The method according to claim 1 characterized in that at the pressure transducer arranged on the line, the pressure change of the liquid or gaseous medium is detected. 3. The method according to any one of claims 1 or 2, characterized in that the medium in the line is heated to change the volume becomes.   4. The method according to any one of claims 1 or 2, characterized in that the medium in the line is cooled to change the volume becomes. 5. The method according to any one of the preceding claims, characterized in that a medium with a low compressibility is used. 6. The method according to any one of the preceding claims, characterized in that water is used as the medium. 7. The method according to any one of the preceding claims 1-5, characterized in that oil is used as the medium.   8. The method according to any one of the preceding claims, characterized in that the medium by means of heating tapes or heating spirals arranged around the line is heated. 9. The method according to any one of the preceding claims, characterized in that the medium is heated by means of a heating element inserted in the line. 10. The method according to any one of the preceding claims, characterized in that the heating or cooling of the medium takes place near the pressure transducer. 11. The method according to any one of the preceding claims, characterized in that the differential pressure between two lines by means of a differential pressure is recorded, with only the medium in the line to be checked Experiences temperature change.   12. The method according to any one of the preceding claims, characterized in that the (differential) pressure sensor is integrated in a (differential) pressure measuring device which the (differential) pressure of the medium (s) is measured. 13. The method according to any one of the preceding claims, characterized in that the degree of permeability or growth of the lines based on a Pressure-time characteristic, in particular a pressure-time diagram, recorded becomes. 14. The method according to any one of the preceding claims, characterized in that the procedure is carried out at defined time intervals. 15. The method according to claim 14, characterized in that the procedure is carried out automatically at defined time intervals.   16. The method according to any one of claims 14 or 15, characterized in that the method is coupled with an alarm function, which starts at a certain th value of the permeability of the line is activated. 17. The method according to any one of the preceding claims, characterized in that from a certain value of the permeability of the line, a safety margin circuit is activated. 18. Application of the method according to one of the preceding claims to a receiving volume (pipe, container, boiler), in particular a steam or Hot water boiler, connected lines, the differential pressure between two areas in the receiving volume by means of one with the respective Area connected line and one arranged between the lines Differential pressure sensor is detected. 19. Apparatus for checking the permeability of lines, the line to be checked being closed at least on one side to a pressure transducer, characterized in that

• - On the line ( 2 ) a pressure sensor for detecting the pressure of the medium in the line and
• - A device for changing the temperature of the medium is provided.

20. The apparatus according to claim 19, characterized in that the device for changing the temperature of the medium near the pressure sensor is arranged. 21. Device according to one of claims 19 or 20, characterized in that a heating device provided as a device for changing the temperature hen is. 22. The apparatus according to claim 21, characterized in that a heating tape is arranged around the line ( 2 ) as a heating device. 23. The apparatus according to claim 21, characterized in that a heating coil ( 6 ) is arranged around the line ( 2 ) as a heating device. 24. The device according to claim 19, characterized in that a heating element is provided in the line ( 2 ) as a heating device. 25. The device according to any one of claims 19-24, characterized in that a differential pressure sensor is provided as the pressure sensor, which is arranged between two lines ( 2 , 2 '). 26. Device according to one of claims 19-25, characterized in that the pressure sensor is integrated in a pressure measuring device ( 4 ). 27. The apparatus according to claim 25, characterized in that the differential pressure sensor is integrated in a differential pressure measuring device ( 5 ). 28. Device according to one of claims 19-27, characterized in that a receiving volume ( 3 , 3 ') is arranged at the ends of both lines ( 2 , 2 '). 29. The device according to any one of claims 19-28, characterized in that the end of the two lines ( 2 , 2 ') leads into a common receiving volume ( 3 ). 30. The device according to claim 29, characterized in that the common intake volume is a steam or hot water boiler.   31. The device according to claim 29, characterized in that the common liquid receiving container is a shell boiler ( 7 ). 32. Device according to one of claims 30 or 31, characterized in that the steam or hot water boiler ( 7 ) has a water area and a steam area arranged above it, with a line ( 2 , 2 ') for differential pressure measurement being connected to the respective area. 33. Device according to one of claims 19-32, characterized in that a comparison electronics for creating a pressure-time characteristic for detecting the degree of permeability of the lines ( 2 , 2 ') is provided. 34. Device according to one of claims 19-33, characterized in that a control device ( 12 ) for automatically checking the permeability of lines ( 2 , 2 ') is provided after defined time intervals. 35. Device according to one of claims 19-34, characterized in that a pressure evaluation unit ( 13 ) is provided. 36. Device according to one of claims 19-35, characterized in that a safety shutdown and / or an alarm device ( 14 ) is provided.