EP1884717B1 - Heating system - Google Patents

Description

The invention relates to a heating system, in particular a gas boiler with two heating circuits according to the features specified in the preamble of claim 1.

Such heating systems are typically compact systems, so-called gas water heaters, which all aggregates and facilities for supplying the radiator for space heating on the one hand and to provide hot service water on the other hand. These are typically provided for wall mounting devices that have a unit in the lower part, which includes the majority of device-side wiring, in particular a circulation pump and a switching valve, the required for the operation of the device sensor and control electronics and ancillaries such as air , Dirt separator and the like. Such units are state of the art, it is in this context EP 1 528 330 A1 directed. The space above the unit is typically provided for the gas burner and the primary heat exchanger located above it.

The structure of such a unit varies depending on the hydraulic design. Variants of such a unit are made EP 0 825 387 A2 known.

In space heating operation, the primary heat exchanger is usually connected directly to the radiators for space heating. However, as soon as hot water is requested, by means of a Switching valve as it is, for example EP 1 655 527 A1 is known, the connection between the primary heat exchanger and the radiators for space heating separated and coming from the primary heat exchanger heated liquid flow into a secondary heat exchanger, typically passed a plate heat exchanger, which is flowed through in countercurrent with hot water and this heated. Once hot tap water is requested by opening a tap, the switching valve is moved in the heating system in the prescribed switching position and beyond ignited the burner to supply the heating circuit with the required energy in the form of heat. The disadvantage here is that especially in the summer, when no heat is needed for the space heating, it takes a relatively long time after opening the tapping point for hot water until heated hot water gets there. This is because the burner is ignited only when the tap is opened and the water in the primary heat exchanger is heated. This must then be promoted to the plate heat exchanger, after which only a warming of the process water can take place, which then still has to cover the conduction path to the tap. Another disadvantage is that when the tap is closed again, still relatively hot water is present within the primary heat exchanger whose heat, especially when the space heater is turned off, can not be removed or used. To avoid this, it is already part of the prior art, after switching off the burner, so when the removal is completed at the tap, to circulate in the primary heat exchanger belindlichen heat transfer through the heat exchanger for domestic water heating in circulation. However, such an arrangement is only very limited use, since even with only slightly calcareous hot water, the most commonly formed as a plate heat exchanger heat exchanger for domestic water heating and thus deteriorates the efficiency of the heat exchanger and can lead to malfunction of the heating system.

In that regard, the cheaper EP 0 931 988 A2 known heating system, in which a bypass line is provided parallel to the primary heat exchanger, through which the heat transfer coming from the primary heat exchanger is fed back to the primary heat exchanger, bypassing the heating circuits. For this purpose, the switching valve is designed so that it has a third switching position in which a line connection is shut off to both heating circuits, so that the return of the heat carrier to the primary heat exchanger übe the bypass line.

Before this prior art, the present invention seeks to improve a generic heating system to the effect that it is structurally simple and inexpensive to produce and easy to maintain.

This object is achieved according to the invention by the features specified in claim 1. Advantageous embodiments are specified in the subclaims, the following description and the drawing.

The heating system according to the invention in particular gas boiler has two heating circuits, one for hot water and one for space heating. The heat transfer medium for both heating circuits is heated in a common primary heat exchanger and fed to the heating circuits by means of a circulation pump. It is provided a switching valve, which incorporates the primary heat exchanger in the first heating circuit and in a second switching position, the primary heat exchanger in the second heating circuit in a first switching position. Furthermore, a third switching position is provided, in which a line connection is shut off to both heating circuits.

This third switch position is provided for the system state, if neither heat in the heating circuit for space heating nor in the heating circuit for domestic water heating heat is required and removed, so typically with switched off space heating after closing the tap for heated hot water. This ensures that the secondary heat exchanger, in which the service water is heated, then, when the service water flow is turned off due to the closed dispensing valve, not further charged with hot water. This arrangement also has the advantage that at least some time still hot water is present directly in front of the secondary heat exchanger, so that faster heated hot water is available when reopening the tap.

In this case, the switching valve is not as in the prior art ( EP 1 655 527 A1 ) form as a 3/2-way valve, but also provide a further switching position, in which the line connection between the primary heat exchanger and the two heating circuits is interrupted.

Characterized in that it is possible with the arrangement to shut off the primary circuit in which the circulating pump is arranged, the circulating pump can be controlled after installation in the heating system so that it runs in the interrupted by the closed valve position without circulation. The thereby absorbed by the pump power is determined and used during later operation of the system to determine without a flow meter alone due to the electrical data of the pump driving motor, whether a promotion is or not. The pump can thus be calibrated automatically at this point with appropriate training of the control electronics.

In this case, not only the line connection to both heating circuits is shut off in this third switching position, but also a bypass line connected in parallel to the primary heat exchanger, through which the heat exchanger coming from the primary heat exchanger, the primary heat exchanger is fed back when the line connection is shut off to the heating circuits. This bypass line not only has the advantage that despite closed heating circuits, a further circulation of the heat carrier and thus a homogenization of the heat level within the primary circuit, but can also be used to ensure that hot water is always present, even if neither the room heating on heated service water is tapped. Characterized in that then hot water is already present at the switching valve, when the tapping point is opened for heated service water and the switching valve lines the primary heat exchanger with the secondary heat exchanger, much faster hot water passed into the secondary heat exchanger, resulting in a faster provision of heated hot water at the tapping point ,

Suitably, a spring-loaded valve, preferably a check valve is arranged in the bypass line, which is dimensioned and arranged so that when the line connection is shut off to both heating circuits, automatically opens by the pressure generated by the circulation pump and thus releases the bypass line for the flow , This check valve ensures that in normal heating operation no hydraulic short circuit is created by the bypass line or the line connection for the bypass line in the switching position in which it is shut off, is depressurized. In a further development of the invention, the construction of the switching valve can be simplified by this arrangement, since the switching valve can then be designed as a simple 3/3-way valve and must not be designed as a 4/3-way valve. By the barrier at both Heating circuits there pending pressure, the check valve is opened automatically and thus released the bypass line.
The switching valve is advantageously designed as a 3/3-way valve, but it can also be a 4/3-way valve are used, then the bypass line connects to the fourth valve port and is released in the switching position when the two heating circuits are shut off.

Conveniently, the switching valve is designed as a seat valve, wherein two valve seats and associated closing body can be provided for a 3/3-way valve, which are preferably spring-loaded in the closing direction. Such a design is on the one hand structurally simple, on the other hand robust, less susceptible to faults in contaminants and has the further advantage that, with a suitable structural design, the valve can open automatically in both overpressure to one and the other heating circuit. For this purpose, it is expedient if the closing bodies are arranged so that they close against the intended flow direction of the heat carrier.

An advantageous embodiment of the switching valve is obtained when the closing body are movably arranged on a common shift rod and the shift rod has drivers which take the respective shooting body only in the opening direction. The closing of the valves then takes place automatically, so that only a comparatively simple mechanism has to be provided for opening.

Advantageously, the valve seats are arranged so that they are facing away from each other and aligned with each other, then a straight common control rod can be used.

The shift rod is advantageously arranged coaxially to the valve seats and guided linearly movable.

A particularly simple, but at the same time functional design results when the shift rod is flared at both ends, wherein there is a helical compression spring between the inside expansion and the adjacent closing body, which force acts on the closing body in the direction of the adjacent driver. The shift rod can then advantageously form the guide for the closing body, which can be designed as a simple and inexpensive to produce disc, which comes to rest on a corresponding annular surface.

According to the invention, the switching valve is designed in the manner of a cartridge, so that it can be incorporated as a finished assembled component in a substantially cylindrical open on one end and lockable by a lid installation space, connect to all the subsequent to the switching valve lines and the bypass line. Such installation spaces can be structurally simple in housing parts are provided, from which units are constructed, which include all the essential units of the heating system, ancillaries and piping. Such units are typically formed of a plurality of plastic injection molded parts, the cheaper they are to produce, the less lost cores are required.

Advantageously, the bypass line is connected in the region between the valve seats of the switching valve to the installation space, so that in connection with the check valve quasi the function 4/3-way valve is achieved without having the otherwise necessary design effort.

The bypass line is advantageously formed according to the invention by a connecting piece of such a plastic housing formed housing component, wherein the check valve is advantageously used in this connection piece from the free end. In this case, the connecting piece according to the invention is arranged and aligned so that it opens directly into the typically provided with such units pump housing part, in the region of the suction mouth of the circulating pump, which is regularly formed inexpensively as a centrifugal pump.

Under heating system in the context of the present invention, only the typically wall-mounted device is to understand, but not in this context also required for connection fixed pipes, pipes and heat exchangers such as radiators for space heating, service water, inflow and outflow lines and optionally outside of the device arranged valves.

The embodiment according to the invention, in particular the provision of a switching position of the valve in which the line connection to both Heating circuits is shut off, in conjunction with the bypass line with check valve (non-return valve) can be advantageously integrated within a structural unit, which is typically present in such heating systems and is constructed of housing and valve components made of plastic injection and absorbs all essential piping, aggregates and ancillaries, so as this is also described by way of example below.

Fig. 1

ein Schaltbild einer erfindungsgemäßen Heizungsanlage,

Fig. 2

in perspektivischer Darstellung eine fertig montierte Baueinheit für die Heizungsanlage nach Fig. 1,

Fig. 3

in perspektivischer Darstellung das das Schaltventil aufnehmende Gehäusebauteil,

Fig. 4

einen Längsschnitt durch das Gehäusebauteil nach Fig. 3 und

Fig. 5

einen Schnitt durch das Gehäusebauteil gemäß Fig. 3 senkrecht zur Längsschnittebene nach Fig. 4.

The invention is explained in more detail with reference to an embodiment shown in the drawing. Show it:

Fig. 1

a circuit diagram of a heating system according to the invention,

Fig. 2

in a perspective view of a fully assembled unit for the heating system according to Fig. 1 .

Fig. 3

in a perspective view of the switching valve receiving housing component,

Fig. 4

a longitudinal section through the housing component after Fig. 3 and

Fig. 5

a section through the housing component according to Fig. 3 perpendicular to the longitudinal section plane Fig. 4 ,

The basis of Fig. 1 shown heating system has a heating circuit in which is heated in a primary heat exchanger 1 by means of a burner 2 circulated water as a heat transfer medium. The water is supplied by means of a circulating pump 3 through the primary heat exchanger 1 and subsequently to a 3/3-way valve, from which it is selectively fed via a check valve of a bypass line 5 or a heat exchanger 6 in the form of a plate heat exchanger or radiators 7 of a space heater. Through the bypass line 5, a return to the circulating pump 3 and thus to the primary heat exchanger 1 takes place in a short path. In the second switching position, the water heated in the primary heat exchanger 1 is the plate heat exchanger 6 supplied, in which it heated hot water in countercurrent, which comes from a service water pipe 8 and heated by a hot water pipe 9 leaves the heat exchanger 6. The guided through the heat exchanger 6 heating water passes through a return line 10 back to the circulation pump 3 and thus to the primary heat exchanger 1. In the third switching position of the valve 4, the heated water in the primary heat exchanger 1 is supplied to the radiators 7 of the space heater and then via a return line 11 again Circulation pump 3 and back to the primary heat exchanger. 1

How out Fig. 1 it can be seen, the components 3 to 6 and 10 and further, not shown in detail in the figure components, are arranged in a structural unit 12 which in Fig. 1 is shown by the 12 numbered rectangular frame.

Such a unit 12, as is typically provided for so-called wall-mounted gas heaters is in Fig. 2 shown. The assembly 12 has a central pump housing part 13, which receives the impeller of the circulation pump 3 and the suction side has an air separator, the quick exhaust fan 14 in Fig. 2 is recognizable. The pump housing part 13 is located at a distance in front of the plate heat exchanger 6 and has a mounting position upwardly directed pressure port 15, which is provided for line connection to the primary heat exchanger 1. The pump housing part 13 carries the front side of the electric motor 16 of the pump. The terminal box 17 of the motor 16 is disposed on the electric motor 16 and receives all the control electronics. Right and left (according to Fig. 2 ) close to the pump housing part 13 so-called fitting housing parts 18 and 19, each consisting of two housing components 20 and 21 or 22 and 23. These are plastic injection molded parts, which each connect to a connection pair of the plate heat exchanger 6.

In the Fig. 2 shown assembly has four downwardly directed ports 27 to 30, which are provided for connection to the stationary, water-carrying lines in the house. In this case, the connection 27 is provided for the heating flow and the connection 30 for the heating return. The hot water is fed via line 8 at the terminal 29 in the unit 12, where it passes from below into the housing member 23 to the in Fig. 2 bottom terminal of the right pair of terminals of the plate heat exchanger 6, flows through this and passes through the lower terminal of the left pair of terminals in the housing member 21 and the hot water supply 28 in the corresponding stationary hot water pipe of the building. In countercurrent thereto, the heated water coming from the primary heat exchanger 1 is introduced via a connection 31 at the top into the housing component 20, which comprises the 3/3-way valve 4 and, for the purpose of heating service water, flows into the upper left connection of the connection plate of the plate heat exchanger 6 the plate heat exchanger in countercurrent to the hot water and exits at the upper port of the right pair of ports back into the housing member 22 which is line connected to the suction port of the pump 3.

The housing components 20, 22 and 23 have in installation position accessible from the front, by means of a bayonetable lid 32 completed cylindrical housings, which contain valves and the like. In the installation space of the housing member 20, the 3/3-way valve 4 is incorporated, which is removable after removal of the lid 32 in the manner of a cartridge assembly.

The housing member 20, as best of Fig. 3 can be removed, the lower port 27 for the heating flow on, from this connecting piece so flows that intended for the radiator 7 of the space heating warm water. It also has a connection 33 extending through a transverse channel to the installation space in the installation position to the rear of the plate heat exchanger 6, through which the hot water coming from the primary heat exchanger 1 via the connection 31 into the housing component 20 is fed to the plate heat exchanger 6 in the switching position provided for the service water heating is through which flows in countercurrent to be heated hot water. Furthermore, the bypass line 5 connects to the installation space parallel to the cross channel leading to the connection 33, the connecting branch 34 of which opens out into the pump housing part 13 is widened and receives a check valve 35 there.

Finally, the housing component 20 has a mounting connection 36 extending between the connection 31 and the connecting piece 34, which accommodates a drive unit 37, via which a control lever 38, which is sealingly guided through the cylinder wall of the installation space, moves about the pivot axis 39 in its pivoting position becomes. The remote from the drive unit 37 end of the control lever 38 is fork-shaped and laterally engages over a shift rod 40 which is thickened in this area to a driver 41, the fork 42 engages positively such that during pivoting movements of the control lever 38, the shift rod 40 in Axial direction is moved. The shift rod 40, which is guided axially movable within the installation space, has at a distance to both sides of the driver 41 two further drivers 43, on which closure members 44 are supported in the form of annular discs and which are arranged movable in the axial direction on the shift rod 40 , The free ends of the shift rod 40 extend beyond the driver 43 and are guided on the housing side. They are surrounded by helical compression springs 45, which are supported on one side of the housing and the other side on the closing body 44 and push it in the direction of the driver 43.

The closing body 44 are sealed to the shift rod 40 and cooperate with the housing side arranged valve seats 46, which are arranged at a distance from each other oppositely directed, as shown in FIG Fig. 4 is shown in detail. In the in Fig. 4 shown neutral switching position are both closing body 44 acted upon by the force of the springs 45 sealingly against the valve seats 46 and thus block the line connection between the terminal 31, so the coming of the primary heat exchanger 1 line both to port 27, so to the radiators 7 of the space heating as well for connection 33 of the plate heat exchanger 6 for heating the service water. In this switching position flows from the primary heat exchanger 1 through the port 31 into the housing component penetrating water through the bypass line 5 through the check valve 35 through the suction port of the circulation pump 3 and from there back to the primary heat exchanger 1, so is performed in a circuit within the device, such as he is described in the introduction. The check valve 35 is spring-loaded, so that this only opens when both closing body 44 sealingly abut the valve seats 46 and builds up a corresponding pressure by the circulation pump 3. At the moment in which by means of the drive unit 37, the valve 4 is reversed, the check valve 35 automatically closes by spring force and prevents a hydraulic short circuit through this bypass line. 5

In addition, the closing body 44 can function in conjunction with the valve seats 46 with suitable dimensioning of the springs 45 as a pressure relief valve, so that in case of failure of the check valve 35 ensures that the valves open automatically due to the pressure generated by the circulation pump 3 and the from Primary heat exchanger 1 heated water can be dissipated in the heating system.

The control of the closing body 44 by means of the drive unit 37, which pivots the control lever 38 about the axis 39 depending on the control, whereby the shift rod 40 in Fig. 4 is led either to the right or to the left. When the shift rod 40 in Fig. 4 is moved to the left, the left in the Fig. 44 closing body 44 is lifted from the valve seat 46 and thus the line connection to the port 27 for the heating flow released, the other closing body 44 remains unchanged in its closed position. When moving the shift rod 40 in the opposite direction remains in Fig. 4 left closing body 44 seals on its valve seat 46 or moves into this position, after which the right-hand closing body 44 lifts off from the right-hand valve seat 46 and releases the line connection between the connection 31 and the connection 33, whereby the heat exchanger 6 is connected in series with the primary heat exchanger 1 becomes.

The valve seats 46 with the closing bodies 44, the shift rod 40 with the drivers and their leadership are formed in a cartridge so that after disengaging the fork 42 of the control lever 38 from the driver 43 and removing the lid 32, the entire unit can be pulled out of the installation space , z. B. for maintenance or repair purposes.

LIST OF REFERENCE NUMBERS

1 -

Primary heat exchanger

2 -

burner

3 -

circulating pump

4 -

3/3-way valve

5 -

bypass line

6 -

heat exchangers

7 -

Radiator (secondary heat exchanger)

8th -

Water pipe

9 -

Hot water pipe

10 -

Return line

11 -

Return line

12 -

unit

13 -

Pump housing part

14 -

vent

15 -

pressure port

16 -

electric motor

17 -

terminal box

18 -

Valve body part, left side

19 -

Valve body part, right side

20 -

Housing component of 18

21 -

Housing component of 18

22 -

Housing component of 19

23 -

Housing component of 19

26 -

connection

27 -

Connection for heating flow

28 -

Connection for hot water, warm

29 -

Connection for hot water, cold

30 -

Connection for heating return

31 -

Connection to the primary heat exchanger

32 -

cover

33 -

Connection to the plate heat exchanger

34 -

spigot

35 -

check valve

36 -

mounting connection

37 -

drive unit

38 -

control lever

39 -

swivel axis

40 -

shift rod

41 -

takeaway

42 -

Fork of 38

43 -

takeaway

44 -

closing body

45 -

Helical compression spring

46 -

valve seats

Claims (13)

1. A heating installation, in particular a gas heater, with two heating circuits, one for warm water provision and one for room heating, whose heat transfer medium is heated in a common primary heat exchanger (1) and is fed to the heating circuits by way of a circulation pump (3), with a switching valve (4) which in a first switch position integrates the primary heat exchanger (1) into the first heating circuit and in a second switch position integrates the primary heat exchanger (1) into the second heating circuit and which comprises a third switch position, in which a conduit connection to both heating circuits is blocked, wherein a bypass conduit (5) is provided parallel to the primary heat exchanger (1), through which bypass conduit the heat transfer medium coming out of the primary heat exchanger (1) is led again to the primary heat exchanger (1) when the conduit connection to both heating circuits is blocked, characterised in that the switching valve (4) is designed in the manner of a cartridge and is envisaged for integration into an essentially cylindrical installation space which is open at a face side, can be closed off by a cover (32) and onto which all conduits connecting to the switching valve (4), and the bypass conduit connect, and that the installation space with the switching valve (4) forms part of a construction unit (12) which is constructed of several plastic injection moulded parts (20-23, 13) and the connection piece (34) forming the bypass conduit (5) connects the installation space directly to a pump housing part (13), in the region of the suction port of the pump (3).
2. A heating installation according to claim 1, characterised in that a spring-loaded valve (35), preferably a non-return valve, which is preferably dimensioned and arranged such that it opens due to the pressure produced by the circulation pump (3) when the conduit connection to both heating circuits is blocked, is arranged in the bypass conduit (5).
3. A heating installation according to one of the preceding claims, characterised in that the switching valve (4) is designed as a 3/3 way valve.
4. A heating installation according to one of the preceding claims, characterised in that the switching valve (4) is designed as a seat valve with two valve seats (46) and in each case associated closure bodies (44).
5. A heating installation according to one of the preceding claims, characterised in that the closure bodies (44) are spring-loaded in the closure direction.
6. A heating installation according to one of the preceding claims, characterised in that the closure bodies (4) close counter to the direction of the flow direction of the heat transfer medium.
7. A heating installation according to one of the preceding claims, characterised in that the closure bodies (44) are arranged on a common shift rod (40) which comprises catches (43) which catch the respective closure body (44) only in the opening direction.
8. A heating installation according to one of the preceding claims, characterised in that the valve seats (46) are arranged away from one another and are arranged in a manner aligned to one another.
9. A heating installation according to one of the preceding claims, characterised in that the shift rod (40) is arranged coaxially to the valve seats (46) and is guided in a linearly movable manner.
10. A heating installation according to one of the preceding claims, characterised in that the shift rod (40) is designed in a widened manner at both ends, wherein a helical compression spring (45) which impinges the closure body (44) with force in the direction to the adjacent catch (41) is arranged between the end-side widening and the adjacent closure body (44).
11. A heating installation according to one of the preceding claims, characterised in that the bypass conduit (5) connects to the installation space, in the region between the valve seats (46) of the switch body (4).
12. A heating installation according to one of the preceding claims, characterised in that the bypass conduit (5) is formed by a connection piece (34) which receives the non-return valve (35).
13. A heating installation according to one of the preceding claims, characterised in that the non-return valve (35) is inserted into the free end of the connection piece (34).

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