METHOD FOR OPERATING A HEATING SYSTEM

Description

[0001] The invention relates to a method for operating a heating system.

[0002] For example, patent document DE 10 2011 001 223 A1 discloses a method for operating a heating system in which a heating circuit medium is conveyed through an overall flow path of a heating circuit, in which the heating circuit medium is conveyed through at least one of at least two partial flow paths of the heating circuit belonging to the overall flow path, and in which the amount of heating circuit medium conveyed via each of the partial flow paths is regulated. In this solution, one partial flow path, which has a whole series of variable flow resistances (in particular, thermostatic valves), is the one with the radiators (represented by the circle with a double line). Another heating circuit, in this case, which has only a single variable flow resistance, is the one with the adjustable bypass valve (see reference numeral 4 therein).

[0003] A further feature of patent claim 1, namely that the heating circuit medium is passed through a filter provided along the entire flow path of the heating circuit in order to clean it of contaminants, is not disclosed in the aforementioned document; however, the applicant assumes that this feature is already known from the prior art.

[0004] The invention is based on the object of improving a method for operating a heating system. In particular, a method for detecting possible contamination of the filter is to be provided.

[0005] This object is achieved by a method for operating a heating system according to claim 1.

[0006] According to the invention, it is therefore provided that during initialization of the heating system, the heating circuit medium is completely guided via the partial flow path which optionally has the least variable flow resistance or a known and / or a constant flow resistance - also called the reference flow path - and a flow rate reference value is determined and stored and that in order to check a contamination state of the filter during operation of the heating system, the heating circuit medium is again completely guided via the reference flow path used during initialization, a flow rate value is determined, this is compared with the flow rate reference value and, from a predetermined deviation, a signal indicating contamination of the filter is generated.

[0007] In other words, the method according to the invention is characterized by the fact that, in order to check for filter contamination, the heating circuit medium is routed through the partial flow path whose flow resistance is best estimated. Such a checking method is significantly more reliable than performing a corresponding diagnosis on the other partial flow path, since the measured volume flow (or the heating circuit medium quantity) is strongly influenced by the other heating circuit components, such as radiators and their thermostatic valves, and it cannot be ensured that the check actually takes place with identical settings, for example, of the thermostatic valves of the radiators.

[0008] The term "complete" used twice in claim 1 is to be understood in the sense of "essentially complete" (i.e. at least 90%, preferably 95%, most preferably 100%), insofar as smaller leakage flows via the other partial flow path which do not influence the reference value formation or the reference value comparison are acceptable.

[0009] Other advantageous developments of the method according to the invention emerge from the dependent patent claims.

[0010] For the sake of completeness, reference is also made to documents EP 0 808 205 B1, EP 1 897 439 A1, and US Pat. No. 9,366,448 B2. While all three documents already disclose devices for detecting filter contamination, none of these solutions, however, provides for directing the flow during measurement data acquisition via the partial flow path whose flow resistance is best estimated.

[0011] Reference is also made to the documents DE 20 2016 006 983 U1, DE 10 2016 218 227 A1 and DE 20 2010 004 292 U1.

[0012] The method according to the invention, including its advantageous developments according to the dependent patent claims, is explained in more detail below with reference to the drawing of a preferred embodiment.

[0013] It shows Figure 1 schematically shows the heating circuit of a heating system with two partial flow paths.

[0014] The single figure shows a heating circuit for carrying out the method according to the invention, in which a heating circuit medium is conveyed through an overall flow path 1.1 of a heating circuit 1, in which the heating circuit medium is conveyed through at least one of at least two partial flow paths 1.2, 1.3 of the heating circuit 1 belonging to the overall flow path 1.1, in which it is regulated how much heating circuit medium is conveyed via the partial flow paths 1.2, 1.3 in each case and in which the heating circuit medium is passed through a filter 2 provided on the overall flow path 1.1 of the heating circuit 1 in order to clean it of contaminants.

[0015] What is essential for the method according to the invention is that when the heating system is initialized (which can be, for example, during initial commissioning, but does not have to be), the heating circuit medium is essentially completely (see above) passed over the partial flow path 1.2 - called reference flow path 1.2 - which optionally has the fewest variable flow resistances or a known and / or unchanging flow resistance, and a flow rate reference value is determined and stored, and that in order to check a contamination state of the filter 2 during operation of the heating system, the heating circuit medium is again essentially completely (see above) passed over the reference flow path used during initialization, a flow rate value is determined, this is compared with the flow rate reference value, and when a predetermined deviation occurs, a signal indicating contamination of the filter 2 is generated.

[0016] It is preferred that the heating circuit medium is supplied to the heating circuit 1 via a flow branch 1.1.1 belonging to the overall flow path 1.1 and is discharged from the heating circuit 1 via a return branch 1.1.2 belonging to the overall flow path 1.1. Likewise, it is preferably provided that the heating circuit medium is passed through a heat exchanger 8 connecting the return branch 1.1.2 to the flow branch 1.1.1. Furthermore, it is preferred that the heat exchanger 8 is designed as a condenser of a heat pump and for dissipating heat to the heating circuit 1. Furthermore, the heating circuit medium is preferably passed through the filter 2 arranged on the return branch 1.1.2 of the heating circuit 1.

[0017] Furthermore, it is preferred that the heating circuit medium coming from the overall flow path 1.1, preferably from the flow branch 1.1.1, is directed by means of a main valve 7 selectively to the reference flow path 1.2 and / or to the other partial flow path 1.3. It is preferred that a 4-3 way valve is used as the main valve 7. Furthermore, it is preferred that the heating circuit medium flowing through the other partial flow path 1.3, which does not form the reference flow path 1.2, is directed through at least one radiator 9 (for example, a heating element).

[0018] It is also preferred that the heating circuit medium is routed through the reference flow path 1.2, which is preferably valve-free apart from the main valve 7, during initialization of the heating system and / or during checking the contamination level of the filter 2. The heating circuit medium is preferably routed through the reference flow path 1.2, which is heat exchanger-free apart from unavoidable heat losses, such as the natural heat dissipation of pipes, during initialization of the heating system and / or during checking the contamination level of the filter 2. Furthermore, it is preferred that the heating circuit medium is routed through a buffer storage tank 6 arranged on the reference flow path 1.2 during initialization of the heating system and / or during checking the contamination level of the filter 2.This is used in particular to provide warm heating circuit medium if the evaporator of the heat pump needs to be defrosted, which can happen in the cold season.

[0019] Furthermore, it is preferably provided that the heating circuit medium is pumped through the heating circuit 1 by a heating circuit pump 3, and a heating circuit medium quantity pumped through the heating circuit 1 is determined by means of a flow meter 4. Additionally, it is preferred that either the flow rate reference value and / or the flow rate value (optionally with the addition of additional operating variables) is determined based on the speed of the heating circuit pump 3 and on the basis of the heating circuit medium quantity detected by the flow meter 4. Finally, it is preferably provided that the flow rate reference value determined during initialization of the heating system is stored in an electronic control device 5 of the heating system.

[0020] The method according to the invention for operating a heating system functions as follows according to a preferred embodiment: When the heating system is first started up, the main valve 7 of the heating circuit 1 is set so that the entire heating circuit medium flows from the flow branch 1.1.1 into the reference flow path 1.2. In the reference flow path 1.2, the heating circuit medium then first flows through the preferably provided buffer tank 6 and then exits the reference flow path 1.2 and enters the return branch 1.1.2. In the return branch 1.1.2, the heating circuit medium then first passes through the heating circuit pump 3, then the filter 2 and then the flow meter 4 before reaching the heat exchanger 8.The speed of the heating circuit pump 3 and the flow rate of the heating circuit medium flowing through the flow meter 4 are now measured, and the flow rate reference value is determined and stored in the heating system's electronic control unit 5. The main valve 7 can now be returned to its original position.

[0021] During regular system operation, the main valve 7 is now adjusted once again so that the heating circuit fluid is only pumped through the reference flow path 1.2. Here, as described above, the speed of the heating circuit pump 3 and the flow rate of the heating circuit fluid flowing through the flow meter 4 are measured again. From these values, the flow rate value is then determined and stored in the electronic control unit 5 of the heating system.

[0022] Finally, the flow rate reference value is compared with the flow rate value and when a previously defined deviation between the two values ​​is reached, a signal is output which indicates contamination in filter 2.

[0023] The method according to the invention thus represents a method for detecting contamination of a filter 2 in a heating circuit which is structurally quite simple, but nevertheless efficient and, above all, provides well-reproducible values. List of reference symbols

[0024] 1 Heating circuit 1.1 Total flow path 1.1.1 Flow branch 1.1.2 Return branch 1.2 Partial flow path - also reference flow path 1.3 Partial flow path 2 Filter 3 Heating circuit pump 4 Flow meter 5 Control device 6 Buffer tank 7 Main valve 8 Heat exchanger 9 Radiator

Claims

1. Method for the operation of a heating system, in which a heating circuit medium is conveyed through a total flow path (1.1) of a heating circuit (1), in which the heating circuit medium is conveyed through at least one of at least two partial flow paths (1.2, 1.3) of the heating circuit (1), belonging to the total flow path (1.1), in which is regulated how much heating circuit medium is conveyed via each of the partial flow paths (1.2, 1.3), and in which the heating circuit medium is routed through a filter (2) provided on the total flow path (1.1) of the heating circuit (1) in order to clean it of impurities. wherein in an initialisation of the heating system, the heating circuit medium is routed completely via the partial flow path (1.2) - referred to as the reference flow path (1.2) - having either the least variable flow resistances, or a known and / or an invariable flow resistance, and a flow rate reference value is determined and stored, and wherein for purposes of checking the contamination status of the filter (2) during operation of the heating system, the heating circuit medium is again routed completely via the reference flow path used during initialisation, a flow rate value is determined, this is compared with the flow rate reference value, and if there is a predetermined deviation, a signal indicating a contamination of the filter (2) is generated.

2. Method in accordance with claim 1, wherein the heating circuit medium is conveyed through the heating circuit (1) by a heating circuit pump (3), and a quantity of heating circuit medium conveyed through the heating circuit (1) is determined by means of a quantity measuring device (4), wherein optionally, the delivery rate reference value, and / or the delivery rate value, is determined on the basis of the rotational speed of the heating circuit pump (3), and on the basis of the heating circuit medium quantity recorded by the quantity measuring device (4).

3. Method in accordance with claim 1 or 2, wherein during the initialisation of the heating system, and / or the checking of the contamination status of the filter (2), the heating circuit medium is routed through the reference flow path (1.2) designed without valves.

4. Method in accordance with one of the claims 1 to 3, wherein during the initialisation of the heating system, and / or the checking of the contamination status of the filter (2), the heating circuit medium is routed through the reference flow path (1.2) designed without heat exchangers.

5. Method in accordance with one of the claims 1 to 4, wherein the flow rate reference value determined during the initialisation of the heating system is stored in an electronic regulation unit (5) of the heating system.

6. Method in accordance with one of the claims 1 to 5, wherein during the initialisation of the heating system, and / or the checking of the contamination status of the filter (2), the heating circuit medium is routed through a buffer tank (6) arranged on the reference flow path (1.2).

7. Method in accordance with one of the claims 1 to 6, wherein the heating circuit medium coming from the total flow path (1.1) is optionally routed by means of a main valve (7) onto the reference flow path (1.2), and / or onto the other partial flow path (1.3).

8. Method in accordance with one of the claims 1 to 7, wherein the heating circuit medium is supplied to the heating circuit (1) via a forward flow line (1.1.1) belonging to the total flow path (1.1), and is discharged from the heating circuit (1) via a return flow line (1.1.2) belonging to the total flow path (1.1).

9. Method in accordance with claim 8, wherein the heating circuit medium is routed through the filter (2) arranged on the return flow line (1.1.2) of the heating circuit (1).

10. Method in accordance with claim 8 or 9, wherein the heating circuit medium is routed via a heat exchanger (8) connecting the return flow line (1.1.2) to the forward flow line (1.1.1).