DE102021128963A1 - Method for monitoring an expansion tank, computer program, machine-readable storage medium, regulation and control device, heater, expansion tank and use of a sensor - Google Patents

Abstract

A method is proposed for monitoring an expansion vessel (6) which has a solid outer shell (12) which contains a receiving area (7) and a compensation area (8), the receiving area (7) and the compensation area (8) being covered by an elastic membrane (10) are separated from each other. The method comprises at least the following steps: a) detecting a signal from a sensor (11), the sensor being able to detect an electrical resistance and/or an electrical capacitance in the compensation area (8), b) comparing the signal detected in step a) with a reference value,c) providing or sending information about the result of the comparison from step b).

Description

The invention relates to a method for monitoring an expansion tank, a computer program, a machine-readable storage medium, a regulation and control device, a heater, an expansion tank and the use of a sensor.

Hydraulic systems, such as heating circuits in particular, have expansion tanks to compensate for volume fluctuations due to temperature differences and pressure surges. The pressure in the hydraulic system can be kept constant as far as possible. Known expansion vessels have a solid, often metallic, outer shell and an internally arranged membrane for separating a receiving area for the hydraulic fluid, for example the heat carrier of a heating circuit, and a gas-filled compensation area. When the hydraulic fluid expands or moves, the diaphragm expands and compresses the gas in the compensation area, which results in pressure equalization. Such expansion vessels are also referred to as membrane expansion vessels (MAG).

Due to aging, for example, the membrane can become leaky and allow the (liquid) heat carrier to escape into the compensation area of the expansion tank. This results in a complete loss of function of the expansion tank. Fluctuations in the volume of the heat transfer medium in the heating circuit can no longer be compensated for and gas from the compensation area can penetrate into the heating circuit.

A leak in the membrane is difficult to detect. To do this, the expansion tank can be tapped and/or the gas valve provided for filling the compensation area can be actuated in order to check whether the heat transfer medium has passed from the receiving area into the compensation area.

In the DE 10 2018 215 304 A1 in this context, it is proposed to provide a sensitive yarn in order to detect damage to the membrane. However, this solution is expensive and complex to manufacture.

Proceeding from this, it is the object of the invention to propose a method for monitoring an expansion tank and an arrangement which at least partially overcomes the problems of the prior art described. In particular, the method and the arrangement should enable reliable, simple and cost-effective monitoring of an expansion tank.

In addition, the invention should at least not significantly increase the complexity of an expansion vessel, or allow existing expansion vessels to be retrofitted.

These objects are solved by the features of the independent patent claims. Further advantageous refinements of the solution proposed here are specified in the independent patent claims. It is pointed out that the features listed in the dependent patent claims can be combined with one another in any technologically meaningful manner and define further refinements of the invention. In addition, the features specified in the patent claims are specified and explained in more detail in the description, with further preferred configurations of the invention being presented.

1. a) Erfassen eines Signals eines Sensors, wobei der Sensor einen elektrischen Widerstand und/oder eine elektrische Kapazität im Kompensationsbereich erfassen kann bzw. erfasst,
2. b) Vergleichen des in Schritt a) erfassten Signals mit einem Referenzwert,
3. c) Bereitstellen oder Versenden einer Information über das Ergebnis des Vergleichs aus Schritt b).

A method for monitoring an expansion vessel contributes to this, the expansion vessel having a solid outer shell containing a receiving area and a compensation area, which are separated from one another (fluid-tight) by an elastic membrane. The procedure includes at least the following steps:

1. a) detecting a signal from a sensor, wherein the sensor can detect or detects an electrical resistance and/or an electrical capacitance in the compensation area,
2. b) comparing the signal detected in step a) with a reference value,
3. c) Providing or sending information about the result of the comparison from step b).

Steps a), b) and c) can be carried out at least once in the specified sequence in a regular process sequence. In particular, it is also possible to repeat steps a) and b) several times or to carry them out continuously or at intervals (as required) at different times. In particular, step c) can only be carried out when certain results of step b) are obtained.

The proposed method is used in particular to monitor an expansion vessel for a leak in the membrane. The method can be carried out, for example, by a regulation and control unit of a heating device of a heating system with such an expansion tank.

The expansion vessel is in particular a membrane expansion vessel (MAG), having a solid outer shell in which a receiving area, for example for heat transfer medium (water) of a heating circuit and a compensation area containing a gas (often nitrogen) is provided. When the heat transfer medium is heated, an increased volume of the heat transfer medium in the heating circuit can be accommodated by the accommodation area. The volume of the receiving area can be increased by stretching the membrane, with the volume of the compensation area being reduced accordingly. For this purpose, the membrane is made of an elastic material, e.g. B. made of rubber. A valve for admitting gas is provided in the outer shell in the area of the compensation area. In other words, the expansion vessel can also be understood as a solid shell, having two chambers separated by a membrane, with the volume proportions of the two chambers being changeable by stretching the membrane.

The method proposed here describes, in particular, a particularly simple and cost-effective way of automatically monitoring an expansion vessel for membrane leakage. In principle, the method can be applied to any expansion vessel with a membrane that separates a receiving area and a compensation area from one another.

In step a), a signal from a sensor is detected, with the sensor being able or detecting an electrical resistance and/or an electrical current and/or an electrical capacitance in the compensation region of the expansion vessel.

In step b), the signal of a sensor detected in step a) is compared with a reference value (an electrical resistance and/or an electrical current and/or an electrical capacitance). The reference value can represent a limit value below which moisture is to be assumed due to heat transfer medium that has penetrated.

In step c), information about the result of the comparison according to step b) is provided or sent. The information can be provided or sent in any way, for example via a display on the expansion tank or also on the heating system or heater, via an acoustic or visual warning signal in the event of a detected leak in the membrane and/or a provision (e.g Retrieving) and/or sending information about a detected leakage of the membrane via a network, in particular the Internet. Advantageously, for example, information about a failure of the expansion vessel can be sent to a specialist company by means of a message, and the specialist company can plan and carry out an appointment to replace the expansion vessel.

Step c) can be carried out in particular depending on the result of the comparison from step b), so that information is only provided or sent when a leak in the membrane is detected.

According to a preferred embodiment, a signal from a sensor can be detected in step a), the sensor being (at least partially) integrated into the outer shell of the expansion vessel. For this purpose, for example, (two) holes can be provided in the outer shell, into which (two) electrodes can be introduced as sensors in a gas-tight manner. In this way, a particularly simple and cost-effective way of carrying out a method proposed here can be realized in an advantageous manner. Equally advantageous is the possibility of retrofitting existing expansion vessels.

According to a further preferred embodiment, the sensor, for example consisting of two electrodes, can be integrated (at least partially) into an existing gas valve of the expansion vessel.

According to a further aspect, a computer program is also proposed which is set up to (at least partially) carry out a method presented here. In other words, this relates in particular to a computer program (product), including instructions which, when the program is executed by a computer, cause the latter to execute a method described here.

According to a further aspect, a machine-readable storage medium is also proposed, on which the computer program is stored. The machine-readable storage medium is usually a computer-readable data carrier.

According to a further aspect, a regulation and control unit for a heating device is also proposed, set up to carry out a method presented here. For this purpose, the regulating and control unit can have a processor, for example, or have it at its disposal. In this context, the processor can, for example, execute the method stored in a (data) memory (of the regulation and control unit). The rule- and control unit can be connected, in particular electrically or in terms of signals, to a sensor for detecting a signal according to step a) in order to carry out a method presented here. A reference value for carrying out step b) can also be stored in a memory of the regulation and control unit.

According to a further aspect, an expansion vessel is proposed, having an outer shell containing a receiving area and a compensation area, which are separated by an elastic membrane, further having a sensor arranged for detecting an electrical resistance and/or an electrical capacitance in the compensation area. In this case, the sensor can in particular comprise two electrodes which are set up to detect an electrical resistance and/or a capacitance (between them). The two electrodes can advantageously be placed in the outer shell or in a gas valve of the expansion vessel.

According to a further aspect, a heater is also proposed, having a regulation and control device proposed here. The heater can in particular be part of a heating system, having a heating circuit with an expansion tank, which can be monitored using a method proposed here.

According to a further aspect, the use of a sensor for detecting an electrical resistance and/or an electrical capacitance arranged in the compensation area of an expansion vessel for monitoring a membrane of the expansion vessel for leaks is proposed.

The details, features and advantageous configurations discussed in connection with the method can accordingly also occur in the computer program presented here, the storage medium, the control device, the heating device, the expansion vessel and/or the use and vice versa. In this respect, full reference is made to the statements made there for more detailed characterization.

A method for monitoring an expansion vessel for leaks and an arrangement for carrying out the method are thus specified here, which at least partially solve the problems described with reference to the prior art. In particular, the method, the arrangement and the use at least contribute to specifying a particularly simple, inexpensive and safe option for monitoring an expansion tank of a heating circuit.

In addition, the invention can be retrofitted to existing expansion vessels without increased effort.

• 1: einen Ablauf eines hier vorgeschlagenen Verfahrens, und
• 2: eine Heizungsanlage mit einem hier vorgeschlagenen Ausdehnungsgefäß.

The invention and the technical environment are explained in more detail below with reference to the accompanying figures. It should be pointed out that the invention should not be restricted by the exemplary embodiments given. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and to combine them with other components and findings from the present description. In particular, it should be pointed out that the figures and in particular the proportions shown are only schematic. Show it:

• 1 : a flow of a method proposed here, and
• 2 : a heating system with an expansion tank proposed here.

1 shows an exemplary and schematic sequence of a method proposed here. The method is used to monitor an expansion vessel 6, which is arranged in a heating circuit 2 of a heating system 1. The sequence of steps a), b) and c) represented by blocks 110, 120 and 130 can occur in a regular method sequence.

2 also shows an example and diagrammatically of a heating system 1, having an expansion vessel 6. The heating system 1 can have a heating circuit 2, in which one or more consumers 4 (e.g. heaters in a building) and a heater 3 are arranged, the latter for heating an im Heating circuit 2 circulating heat carrier (z. B. water) is set up. The expansion tank 6 can have a solid and pressure-resistant outer shell 12, for example made of steel, and an elastic membrane 10. The elastic membrane 10 divides the volume enclosed by the outer shell 12 into a receiving area 7 and a compensation area 8. The elastic membrane 10 can be made of an elastic fabric or rubber, for example

The expansion tank 6 can be (fluidically) connected to the heating circuit 2 in such a way that the heat transfer medium can flow from the heating circuit into the receiving area 7 of the expansion tank 6 and vice versa. When the heat transfer medium is heated in the heating circuit 2 by the heater 3 or a pressure wave therein and an associated expansion/displacement of the heat transfer medium, the heat transfer medium flows into the receiving area 7 of the expansion vessel 6. The volume can thus men of the receiving area 7 of the expansion vessel 6 increase, associated with an (elastic) expansion of the membrane 10. At the same time, the gas is compressed in the compensation area 8, and the volume of the compensation area 8 decreases.

A valve 9 can be arranged in the outer shell 12 of the compensation area 8 , via which the compensation area 8 can be filled with a gas, for example nitrogen, with a defined pressure as counter-pressure for the heating circuit 2 .

Furthermore, a sensor 11 for detecting an electrical resistance and/or a capacitance of an area in the compensation area 8 can be arranged in the outer shell 12 of the compensation area 8 . The sensor can be designed, for example, as two electrodes arranged in the outer shell 12 of the combination area 8 .

The sensor 11 of the expansion vessel 6 can be connected electrically and/or in a data-conducting manner to a regulation and control unit 5 of the heater 3 . The regulation and control unit 5 can be set up to carry out a method proposed here.

In block 110, according to step a), a signal of the sensor 11 is detected. An electrical resistance and/or an electrical capacitance is detected.

In block 120, according to step b), the signal of sensor 11 detected in step a) is compared with a predetermined reference value. The reference value can be an electrical resistance or an electrical capacitance below which (undesirable) moisture in the compensation area 8 is to be assumed. The reference value can advantageously be stored in a memory of the regulation and control device 5 .

In block 130 according to step c), information about the result of the comparison in step b) can be provided or sent. In particular, information about a leak in membrane 10 detected in step b) (block 120) by falling below the reference value can advantageously be sent as a message via a network, in particular the Internet, to a specialist company, for example.

Reference List

1

heating system

2

heating circuit

3

heater

4

consumer

5

regulation and control unit

6

expansion tank

7

recording area

8th

compensation area

9

Valve

10

membrane

11

sensor

12

outer shell

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102018215304 A1 [0005]

Claims (9)

Method for monitoring an expansion tank (6), having a rigid outer shell (12) including a receiving area (7) and a compensation area (8), which are separated by an elastic membrane (10), comprising at least the following steps: a) detecting a signal from a sensor (11), the sensor being able to detect an electrical resistance and/or an electrical capacitance in the compensation area (8), b) comparing the signal detected in step a) with a reference value, c) Providing or sending information about the result of the comparison from step b). procedure after claim 1 , wherein in step a) a signal of a sensor (11) is detected, which is integrated into the outer shell (12) of the expansion vessel (6). Method according to one of the preceding claims, wherein in step c) information about the result of the comparison is sent via a network. Computer program set up to carry out a method according to one of the preceding claims. Machine-readable storage medium on which the computer programs claim 4 is saved. Regulation and control device (5) for a heater (3) set up to carry out a method according to one of Claims 1 until 3 . Heater (3) having a regulation and control unit (5). claim 6 . Expansion vessel (6), having an outer shell (12), containing a receiving area (7) and a compensation area (8), which are separated by an elastic membrane (10), further having a sensor (11) for detecting an electrical resistance and /or an electrical capacity in the compensation area (8). Use of a sensor (11) for detecting an electrical resistance and/or an electrical capacitance in the compensation area (8) of an expansion vessel (6) for monitoring a membrane (10) of the expansion vessel (6) for leaks.

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