DE2854561A1 - Heating circuit mixture valve - has hole between two compartments with alterable cross section to vary hot water input - Google Patents

Abstract

The mixture valve is for two interconnected circuits for heat exchange in water-operated heating installations, with at least one high and one low temp. branch. Two connections on the mixture valve are for low temp. water forward and back flow. A third connection is for hot water input. Inside the valve is a two-part mixture chamber, whose divisions are connected via a hole with controllable aperture size. The opening (26) between the mixture chamber divisions (24, 25) is variable an independently adjustable control component (32) to adjust the volume of hot water input.

Description

2Ι54Ϊ61

Note: Franz-Josef Hagemann, 4434 Ochtrup, Feldkamp 10

Bernd Hewing, 4434 Ochtrup, Hellstiege 10

Mixing valve for coupled circuits

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The invention relates to a mixing valve for circuits coupled to one another for heat exchange water-operated heating systems with at least one high-temperature (HT) and one low-temperature (LT) branch, with two connection nozzles attached to the mixing valve for the flow and return of the LT water and a third connection for the inlet of the HT water, as well as with one located inside the valve, two-part mixing chamber, the departments of which are connected to one another via a controllably variable opening are connected.

As is known, for example, from DE-OS 2 461 699, such mixing valves are used in particular in underfloor heating used. Such water-operated heating systems have heat exchangers in the screed are laid and usually with a flow temperature of 45 C and a return temperature from 39 C to work. These temperature values are general empirical values and are specified by the respective Design of the transmission surfaces. In contrast, the flow water that comes directly from the boiler or has is supplied by a district heating system - the HT-

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Water - a temperature of 80 - 120 ° C.

In order to establish a coupling between the high-temperature and the low-temperature branch, the the mentioned DE-OS known mixing valves used, which a heat transfer from the high temperature in allow the low-temperature branch. In particular, when using such valves, so-called B ypass lines avoided. Furthermore, the task generally arises for such mixing valves that it is prevented with certainty that the water of the high-temperature branch even with incorrect operation of the circuit flow into the low-temperature branch in too large quantities and cause damage here can. On the other hand, the coupling should be inexpensive to carry out and with control elements (e.g. servomotors) can be equipped.

While these tasks have largely been solved by mixing valves of the known type, it has been found that there is a certain difficulty in dimensioning and carrying out the control processes occurs in that the opening between the mixing chamber compartments, which is divided into a partial opening to the LT return and one to the HT flow

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A fixed ratio of these two partial flows results, which changes the amount of the opening by a valve body control, but not in relation to this ratio
is controllable. As a result, it can happen that relatively small
Adjustment angles of the valve member cause disproportionately large changes in temperature of the mixed water, so that precise regulation and in particular regulation fluctuations cannot be avoided.

Another problem is the pipe resistance in the heating circuit branches, which varies from system to system. Ideally, the HT and LT circuits should have the same pipe resistances; already different distances from the boiler house and
very different individual resistances, which are often only
on site, make this requirement difficult to meet.

In addition, the performance of the boiler pumps cannot be optimally designed so that correction options are required.

The task is thus to be able to correct such system-related errors in a simple manner without parts of the
Having to install or remove heating.

In the case of a mixing valve, the stated object is the one at the beginning
mentioned type solved in that the opening between the
Mixing chamber compartments with adjustable flow path and cross-section of the opening independently of the control of the opening

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entering HT water fixing adjusting member is changeable.

Such a mixing valve enables not only the solution mentioned above Task also that with fluctuating flow water temperatures, as they occur in hot water storage heating systems that Changing the setting of the adjusting element can be used to compensate for the fluctuations with the help of a temperature sensor and Servomotor to compensate for the existing control circuit.

An embodiment has proven to be advantageous in which designed the adjusting member and the valve body controlling the opening as two disc-shaped bodies lying one on top of the other are. This configuration can be accommodated particularly elegantly in the confines of the mixing valve space.

In order to achieve an adjustment that is favorable in terms of flow and an adjustment characteristic that is as linear as possible by means of the adjusting element the adjusting member is disc-shaped and has a bulged S-shape.

So that the adjusting member can perform a defined and limited movement, it is proposed that the mixing chamber in the area half of its height has an inwardly projecting flange part with bearing groove (s) in which or in which with the adjusting member connected webs can execute a movement limited by stop surfaces.

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As an advantageous design of a disk-shaped adjusting member when used in a Cylindrical mixing chamber, the adjusting member of two is rotationally symmetrical by about 180 degrees arranged around the center, on their side facing the mixing chamber inner wall curved outer surfaces having sections, in which the radius of curvature of the outer surface of the chamber inner wall seen from here, is steadily shortened.

Mixing valves usually have the type mentioned at the beginning Type of abutment attached to the front wall for the actuating shaft of the valve body. For such Mixing valves is proposed that the adjusting member is on the free top of the abutment supports.

In this case it is also advantageous if the adjusting member has an elongated hole surrounding the shaft is provided.

Finally, in order to be able to move the adjusting member, it is proposed to use this with one of the To couple valve housing protruding, movement-transmitting rod or shaft.

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Further properties of the mixing valve according to the invention emerge from the following description of an exemplary embodiment emerged. The figures of the drawing show:

Figure 1 shows a heating circuit with a mixing valve according to the invention;

FIG. 2 shows a mixing valve in an exploded, perspective illustration;

FIG. 3 shows a section with a plan view of the interior of the mixing chamber;

FIG. 4 shows a section with a side view of the mixing chamber.

Figure 1 shows a schematic representation of a coupled circuit of a water-operated heating system, consisting of a high-temperature branch 1 and a low-temperature branch 2. In the high-temperature branch 1 there is a boiler 3. The return 4 of the HT branch 1 has, for example, under normal conditions a temperature of 39 C, while the temperature in the flow 5 is about 90 ° C. The temperature

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--8T-

1456 t

The difference between flow and return is therefore Δ t = 51 ° C.

The forward flow passes through a mixing valve 10, the exact function of which will be explained below. It is then guided over floor heating elements 12, 13 by a pump 14. From there it flows via a return line 7 via a T-piece 8
back into the return line 4, which is directly connected to the boiler, is heated in the boiler 3 and then the cycle begins again.

It is essential that not all of the 90 ° hot water is fed into the surface heating elements, but that cooling is carried out via the mixing valve 10
he follows. For this purpose, a connecting line 9 is provided which connects the return line 7 via the T-piece 8 to the mixing valve inlet. With the help of the mixing valve 10, high-temperature heating water is dosed from the flow line 5 into the line 11 of the
NT branch entered.

To get an idea of the amount of water flowing in the two branches, assume a heating requirement of 3O,000 kcal / h. Since in
Low-temperature branch Δ t is kept at 6 C.

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(Inlet temperature 45 ° C; outlet temperature 39 ° C), 5,000 l / h must be circulated in this branch. In contrast, & t (branch 1) = 51 ° C, so that with the same Only 588 l / h of calories have to be circulated.

To the temperature difference A t within the branch 2 after passing through the coupling path with branch 1 again, this is shown in FIGS Mixing valve 10 shown to 4 is used. The valve 10 is seen from the outside as a kind of T-piece worked. The individual inflow and outflow nozzles are, however, dimensioned differently, as is the case with the Function requires.

The mixing valve 10 according to FIGS. 2 to 4 has a valve housing 16 which has a permanently installed base

17 and an inside and outside approximately cylindrical jacket

18 owns. In the jacket 18 three bores with adjoining connecting pieces 20, 21, 22 are provided, the connecting pieces 20 and 21 being in a first (lower) level and the connecting piece 22 being in a second (upper) level. The mixing chamber 23 is divided into two parts, the two compartments 24 (above) and 25 (below) being connected to one another by a controllably variable opening 26 »

The bore belonging to the nozzle 2O opens into the lower section of the mixing chamber. This neck is with the flow line 5, which is with the high-temperature water comes from boiler 3, connected. In contrast, the nozzle 21 with the return line 9 of the Low temperature circuit connected. In the lower Department, an abutment 27 connected to the floor is installed, the side wing-like partition walls 28 carries, which are connected to the inside of the lower compartment. The partitions take care of it for a separation of the two incoming water flows. In the abutment 27 protrudes a shaft 2? ' (see. Figure 4), which is arranged vertically and to which a valve body 29 is rigidly connected. The valve body 29 has approximately the shape of a semicircular disc. It rests at the edge on an inwardly protruding, annular projection 30, a sealing surface being formed at the same time. When rotating of the valve body 29 are, respectively, different areas the lower compartment, which is separated into two different cells by the partition 28, is released, so that controlled proportions of relatively hot or cold water in the upper department the mixing chamber and can mix there. The movement of the shaft 27 'can .manual or

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- usually - can be changed in their position by a servomotor, so that the opening 26 can be changed.

Below the valve body 29 there is another disk-shaped device: the adjusting member 32. It is not connected to the shaft 27 ', but surrounds the shaft with an elongated hole 33 loose from the outside. The adjusting member 32 is arranged in such a way that it opens the opening between the mixing chamber compartments 24, 25 with an adjustable independently of the control of the valve body 29, the Define and change the flow path and cross-section of the entering high-temperature water. The adjusting member is also designed in the shape of a disk with approximately the same thickness as the valve body and, seen from above, has a bulged S-shape. The one in the area halfway up the mixing chamber internally protruding projection 30 has two bearing grooves 35, 36, in which connected to the adjusting member 32 Web 37, 38 can execute a movement limited by stop surfaces. This movement is made possible by a, connected to the adjusting member, protruding from the valve housing shaft 39, which with the Member 32 is coupled. Part 32 supports this

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on its underside a threaded shoe 40, in whose threaded bore the threaded end of the shaft 39 protrudes, so that when the shaft is rotated, the adjusting member 32 can be set in the movement indicated by the arrow direction (see FIG. 2). To the outside, the shaft 39 can be adjusted manually or by a motor with the aid of a handwheel (not shown), an adjusting motor * or the like, usually it is provided that only one adjustment is made and then the adjusting member ³ and the shaft 3!
term nut 41 is set.

^{Adjusting member 3} ünd the shaft 39 with the help of a con

As can be seen from FIG. 4, the adjusting member 32 is supported with its underside on the free one Top of the abutment 27 as well as with its webs 35, 38 off. It is held down by the threaded shoe that is connected to the shaft 39.

As can be seen from Figures 2 and 3, this has Adjusting member 32, seen from above, a bulged S shape. This form can be described more precisely that'tfzwefi are rotationally symmetrical by about T80 sections arranged around the center on * foren ,, the side facing the Mschkammer-you side

have curved outer surfaces, in which the radius of curvature is based on that in the area of the web 3 7 or 3 8 located starting point is steadily shortened. This creates a contour that is partially has a surface which is quasi-parallel to the inner wall of the mixing chamber and then a space 42 leaves open, which is still a clear in the two extreme positions of the adjusting member Flow mode that leaves a minimum flow guaranteed.

It should also be mentioned that the adjustment element and valve body from the lower section of the mixing chamber Water flowing past is in the upper compartment mixes due to the turbulent flow and flows out through the nozzle 22, which is connected to the line 11 of the heating circuit according to Figure 1 is connected. To

43 above, the housing is secured by a cover, as in Figure 4 shown schematically, tightly closed. The nozzles 20, 21 and 22 can still be equipped with relief and Cleaning valves may be provided, which, however, are not shown in the drawing.

The following comments on the mode of operation of the mixing valve described:

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The mixing valve described in the figures is also functional without the adjusting member 32. In this case it essentially corresponds to two-chamber mixing valves known per se. The water coming from the nozzle 20, 21 is controlled in its quantitative composition with the help of the partition walls 28 and the semicircular valve body 29. It turns out, however, that with jälscher
Dimensioning the valve capacity for reduced heating requirements or similar circumstances
hot feed water is so large that comparatively small changes in the angle of rotation of the valve body 29 lead to an excess or shortage of hot feed water. In this case, incorrect controls and faulty shutdowns can occur. On the other hand, with the new mixing valve it is possible, for example, to throttle the hot water flow to a minimum from the outset, so that at an angle of rotation of, for example 100, the full "available hot water quantity can be turned on and fully turned up. According to the needs and conditions of seasonal operation accordingly the hot water quantities of
be dimensioned in advance.

In addition, special features of the individual heating circuit, for example large amounts of heat required

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for heating a heat storage boiler, separately be controlled, for example with the help of a servomotor, two fixed positions of the adjusting member 32 are programmable. It is also possible to have water resistances that differ at different levels Heating devices turn out differently than expected, balance.

In addition, the adjusting member 32 can of course also be exchanged. This is the warehousing rationalized, because with a single basic model and various adjusting members 32 can be a wide Cover a range of possible uses.

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Claims (8)

Patent claims: \ Λ A Mixing valve for interconnected circuits of water-operated heating systems for heat exchange with at least one high temperature (HT) and one Nxedertemperature (LT) branch, with two connecting pieces attached to the mixing valve for the flow and return of the LT water and a third connection for the inlet of the HT water as well as a two-part mixing chamber located inside the valve, the departments of which are connected to one another via a controllably variable opening, characterized in that the opening (26) between the mixing chamber compartments (24, 25) with a flow path and cross-section that can be adjusted independently of the control of the opening the adjusting member (32) defining the entering HT water can be changed. 2. Mixing valve according to claim 1, characterized in that the adjusting member (32) and the one controlling the opening Valve body (29) are designed as two disc-shaped bodies lying on top of one another. 030025/04 3. Mixing valve according to claim 1 or 2, characterized by an adjusting member which is designed in a disc-shaped manner and has a bulged S-shape. 4. Mixing valve according to claim 2 or 3, characterized in that the mixing chamber in the region of their half height an inward protrusion (30) with bearing groove (s) (35, 36) in which or in which connected to the adjusting member Web (37, 38) can execute a movement limited by stop surfaces. 5. Mixing valve according to claim 2 and 4, characterized in that the adjusting member with cylindrical shape Mixing chambers made up of two rotationally symmetrical about 180 ° arranged around the center, on its side facing the mixing chamber inner wall There is curved outer surfaces having sections, in which the radius of curvature of the outer surface starting from the inner wall is continuously shortened. 6. Mixing valve according to claim 1 with an abutment attached to the end wall (the bottom) of the mixing chamber for the actuating shaft for the valve body, Q30025 / 048 « 854591 characterized in that the adjusting member (32) rests on the free upper side of the abutment (27) supports. 7. Mixing valve according to claim 6, characterized in that the adjusting member is provided with an elongated hole (43) surrounding ^{the shaft (27 1).} 8. Mixing valve according to claim 1, characterized in that the adjusting member with one of the valve housing protruding, motion-transmitting rod or shaft is coupled. 03007 5 / OÄ86