DE202009003191U1 - Cascade unit for a heating system with two or more boilers - Google Patents

Abstract

Cascade unit (1) for a heating system with two or more boilers, wherein the cascade unit (1) has at least one horizontally extending in the operating state boiler flow collector (3) and boiler return manifold (4), wherein the boiler flow collector (3) and the boiler return manifold (4) respectively equipped with prepared boiler connections (32, 42) arranged for a group of two or more boilers, for connecting the boiler feeders and the boiler return flows, the cascade unit (1) further comprising a hydraulic switch (5) which is connected to the boiler feed collector ( 3) and boiler return manifold (4) and on the other hand with at least one heating circuit flow connection (55) and heating circuit return connection (56) is fluidly connected, and wherein the collector (3) and the manifold (4) and the hydraulic switch (5) together to a prefabricated Assembly are mechanically connected,
characterized,
- That the hydraulic switch (5) in the operating state is arranged horizontally and parallel to the boiler flow collector (3) and boiler return manifold (4) and
- that the boiler flow collector (3) and the boiler return manifold ...

Description

The The present invention relates to a cascade unit for a heating system with two or more boilers, the cascade unit at least one each in the operating state horizontally extending boiler flow collector and boiler return manifold, wherein the boiler flow collector and the boiler return manifold each with prepared, adapted for a group of two or more boilers Placed boiler connections for connecting the boiler inlets and the boiler returns are, wherein the cascade unit continues to be a hydraulic switch on the one hand with the boiler flow collector and boiler return manifold and on the other hand with at least one each heating circuit flow connection and heating circuit return port fluidly is connected, and wherein the collector and the distributor and the hydraulic Turn each other mechanically into a prefabricated unit are connected.

A cascade unit of the aforementioned type is z. B. from the DE 202 11 303 U1 known. In this known cascade unit is provided that the hydraulic switch in the operating state of the cascade unit is oriented substantially vertically and is mechanically fixed near its lower end with the boiler flow collector and the boiler return manifold.

Out this arrangement of boiler flow collector and boiler return manifold in a horizontal direction on the one hand and the hydraulic Switch in a substantially vertical direction on the other hand results in a bulky construction, which in logistics, that is during storage and transport, a lot of space is required. Also needed in a room of an associated heating system the well-known cascade unit relatively much space. After all is in the known cascade unit attaching a thermal Insulation relatively expensive.

For The present invention therefore has as its object, a cascade unit to provide the type mentioned, the disadvantages set forth avoids and in particular a more compact arrangement with a smaller space requirement both in logistics and on the Site is reached and when attaching a thermal Isolation is simplified.

The Solution of this task succeeds according to the invention a cascade unit of the type mentioned, characterized gekennzeichnbet, that the hydraulic switch in the operating state horizontal and parallel to the boiler flow collector and the boiler return manifold is arranged and that the boiler flow collector and the boiler return manifold spaced apart and mechanically with the hydraulic switch are connected.

With The cascade unit according to the invention will be advantageous achieved a very compact design, because both the boiler flow collector and the boiler return manifold as well as the hydraulic switch all arranged horizontally and thus parallel to each other are. This simplifies logistics and installation the cascade unit in a boiler room takes up less space. Assembly work to connect the hydraulic switch with the Boiler flow collector and the boiler return manifold fall not at the place of installation, because the parts mentioned already mechanically are connected. The invention further provided Arrangement of boiler flow collector and boiler return manifold By far from each other ensures that an undesirable heat transfer between the hot boiler forerunner and the cooler one Boiler return manifold is largely avoided. By the compact design and the distance from the boiler flow collector and boiler return manifold from each other is attaching a thermal insulation jacket significantly simplified. Between Boiler flow collector and boiler return manifold a distance can also exist in the area between boiler flow collector and boiler return manifold introduced insulating material be what the desired thermal separation of boiler flow collector and boiler return manifold further improved.

A further embodiment of the cascade unit according to the invention provides that the heating circuit supply connection and the heating circuit return connection both arranged at a first end face of the hydraulic switch are. The arrangement of the two heating circuit connections to the same Front end of the hydraulic switch results in a compact arrangement also these two connections and facilitates the cable routing during the installation of the cascade unit and the other parts an associated heating system.

Especially for reasons of cost-effective production and to achieve a stable construction of the cascade unit further provided that the or each boiler forerunner and the or each boiler return manifold and the hydraulic Switches are each formed by a rectangular tube section.

A further embodiment of the cascade unit proposes that it each has a boiler flow collector and boiler return manifold that the rectangular pipe section forming the hydraulic switch has a height which is greater than that added heights of boiler flow collector and boiler return manifold, and that the boiler flow collector and the boiler return manifold, preferably outside edge flush, are arranged on the front or the rear of the hydraulic switch. This embodiment of the cascade unit advantageously has a relatively small overall depth, which is advantageous in many installation situations.

In an alternative embodiment of the cascade unit is provided that they each have a boiler flow collector and boiler return manifold has, that of the hydraulic switch forming rectangular tube section has a width that is greater than the added one Widths of boiler flow collector and boiler return manifold, and that the boiler feed collector and the boiler return manifold, preferably outside edge flush, at the top or the underside of the hydraulic switch are arranged. This embodiment The cascade unit has the specific advantage of being particularly low Construction, what with appropriate installation situations in heating rooms, especially in rooms with low height, advantageous can be.

A Another embodiment of the cascade unit provides that they ever a boiler flow collector and boiler return manifold has, that of the hydraulic switch forming rectangular tube section has a height equal to or greater than the height of the boiler return manifold is that the boiler return manifold, preferably flush with the lower edge, at the front or rear of the hydraulic switch is arranged and that the boiler flow collector, preferably flush with the outside edge, is arranged at the top of the hydraulic switch. In this The cascade unit has a particularly flat design Construction, as they except their lower part, in which the switch front or rear the boiler return manifold carries, has a depth which is not greater than the overall depth of the hydraulic switch only.

With the cascade units described above, each with a boiler flow collector and boiler return manifolds can be two or more Boiler connected in a row next to each other.

ever according to spatial conditions, it may also be appropriate be with the cascade unit two or more boilers in the form to arrange by couples back to back. A first Embodiment of the cascade unit for such a boiler arrangement is characterized in that it is a boiler flow collector and two boiler return manifold has that the hydraulic soft rectangle pipe section forming a height equal to or greater than the height each boiler return manifold is that the boiler return manifold, preferably lower edge flush, at the front and the back of the hydraulic switch are arranged and that the boiler flow collector, preferably flush with the outside edge, is arranged at the top of the hydraulic switch. These Cascade unit needed despite the arrangement of, boilers Back to back only a single boiler forerunner, allowing a particularly economical cascade unit available is provided.

A alternative embodiment of the cascade unit provides that They each have two boiler feed headers and boiler return manifolds has, that of the hydraulic switch forming rectangular tube section has a width that is greater than the added one Widths of each one boiler feed collector and boiler return manifold, that the boiler flow collector, respectively, preferably flush with the outer edge, on the top or the bottom of the hydraulic switch arranged and that the boiler return manifolds each, preferably flush with the outside edge, at the bottom or the Top of the hydraulic switch are arranged. This execution the cascade unit has a relatively low height, which for low boiler rooms is beneficial.

A Further embodiment of the cascade unit is characterized in that that it has two boiler feed headers and one boiler return manifold each, in that the rectangle pipe section forming the hydraulic switch has a height that is greater than the added heights of each boiler advance collector and Boiler return manifold that the boiler flow collector, preferably flush with upper or lower edges, laterally on both sides are arranged on the hydraulic switch and that the boiler return manifold, preferably lower or upper edge flush, laterally on both sides are arranged on the hydraulic switch. This execution the cascade unit again has the specific advantage of being relative small depth, which in corresponding installation situations in one Heating room can be beneficial.

The cascade units according to claims 3 to 9 described above each have one or two boiler feed headers and one or two boiler return manifolds each in the form of a rectangular pipe section. Alternatively, according to a further embodiment of the cascade unit according to the invention, the possibility that the hydraulic switch is formed by a rectangular pipe section and that the boiler flow collector and the boiler return manifold are formed by two parallel pipe sections whose facing sides are each formed by a wave or zigzag wall wherein the two wave or zigzag walls are parallel and spaced apart. This off Design of the cascade unit offers the possibility of arranging the boiler flow connections and the boiler return connections in a common straight line, which makes it easier to connect the cascade unit to the boilers and makes them visually more appealing. At the same time, however, the desired thermal separation between the boiler flow collector and the boiler return manifold is maintained by the distance between their wavy or zigzag, facing walls.

The The most compact arrangement of the cascade unit is achieved when is provided that the boiler flow collector and the hydraulic Soft flat against each other mechanically are connected and the boiler return manifold and the Hydraulic soft flat against each other mechanically connected.

alternative there is the possibility that the boiler forerunner and the hydraulic separator with distance between their each other facing surfaces are mechanically connected to each other and that the boiler return manifold and the hydraulic Turn the distance between their facing surfaces mechanically connected to each other. This execution The cascade unit offers a particularly good thermal separation between the individual parts of the cascade unit.

A Further substantial simplification of production, logistics and Installation results when the cascade unit according to the invention so is carried out that the boiler connections to Connection of boiler feeders and boiler returns are arranged symmetrically on the cascade unit in the manner that after a rotation of the cascade unit by 180 ° to one transverse to the longitudinal direction of the cascade unit horizontally or vertical axis of rotation one to the output assembly identical arrangement of the boiler connections results, but the heating circuit flow connection and the heating circuit return connection come to rest at the other end of the cascade unit. At a such symmetrical design of the cascade unit is sufficient a single execution of the cascade unit for two different installation situations, in which once the heating circuit connections at one end face and once at the other end of the Cascade unit lie. Thus, errors in the order of Cascade unit avoided by the installer. Furthermore so there is the possibility, even immediately before installation the cascade unit in a boiler room, the arrangement of the cascade unit appropriate to choose.

to Ensuring a good function of the hydraulic switch within the cascade unit is further provided that the hydraulic switch a lead-in area, a return area and a core core area having, wherein these areas fluidly are interconnected, wherein the core core area fluidly between the flow area and the return area is and where the flow area with flow the boiler feed collector and the return area fluidly connected to the boiler return manifold. In balanced Volume flows on the one hand in the boiler circuits and on the other hand in the heating circuit no flow occurs in the soft core area on; only the flow area and the return area the hydraulic switch is flowed through. Between Flow area and return area of the hydraulic separator the non-flowed Weichenkernbereich is disturbing the currents in the flow area and in the return area not each other. Only in operating states of an associated Heating system in which the volume flows in the boiler circuits on the one hand and in the heating circuit on the other hand are not balanced, this results in a compensation flow through the soft core area therethrough. This will in case of unbalanced currents a compensation of the flow rates produced automatically. For example, it is excluded that the to the cascade unit connected boiler too low water flow which is easy to use, especially in modern condensing boilers Damage to their heat exchangers could.

A further embodiment of the cascade unit proposes the hydraulic switch before that the subdivision of the hydraulic Soft is formed by a partition, that of the first front end the hydraulic switch between heating circuit supply connection and Heating circuit return connection starting in the direction of second front end of the hydraulic diverter extends and at a distance ends before the second front end of the hydraulic switch. The partition forms a very simple and at the same time functionally reliable separation the hydraulic switch in the flow area, Weichenkernbereich and return area. As a result, the production of the cascade unit remains simple and cost-effective.

A further embodiment in this regard provides that at or near the end of the dividing wall facing the second front end of the hydraulic switch, a diaphragm is arranged with a passage between the flow region and the soft core region. The orifice with the passage ensures, in particular, that unwanted flows through the soft core region as a result of temperature differences in the heat transport medium or water, which flows through the cascade unit, do not occur to a disturbing extent. Equal Of course, the passage is of course chosen so large that any necessary compensation flows are not disturbed by the soft core area of the hydraulic switch.

A in terms of subdivision of the hydraulic switch alternative Design of the cascade unit is characterized in that the subdivision of the hydraulic separator through a pipe socket is formed, which from the first front end of the hydraulic switch either from the heating circuit supply connection or from the heating circuit return connection starting in the direction of the second front end of the hydraulic Soft extends and ends at a distance in front of the second front end. The pipe socket is a technically simple component with which the desired subdivision of the hydraulic switch functional reliable and in the production of the cascade unit is achieved inexpensively.

Around also in the cascade unit with the pipe socket for subdivision hydraulic switch unwanted, due to temperature differences in the heat transport medium caused currents by avoiding the soft core area is provided here that at a distance from the first front end of the hydraulic switch a diaphragm with a passage located in a lower switch area arranged between the lead-in area and the soft core area is. Again, of course, the passage is like that dimensioned that the possibly required compensation flow by the soft core area to a sufficient extent possible remains.

If useful or necessary, can also be between the soft core area and the return area of the switch an aperture with a defined passage for the heat transport medium be provided.

One further contribution to a technically simple structure and thus to a cost manufacturability of the cascade unit is achieved in that preferably the fluid Connection between the hydraulic separator and the boiler flow collector and the fluid connection between the hydraulic diverter and the boiler return manifold in each case by congruent breakthroughs sealed to the outside in adjoining or facing surface areas of hydraulic switch on the one hand and boiler flow collector and on the other Boiler return manifold on the other hand are formed. With This configuration are complex external cable connections what keeps the cascade unit simple and compact.

Especially to avoid disturbing turbulences within the cascade unit is provided that the heating circuit flow connection a smaller Has cross-section as the boiler flow collector and that the heating circuit return connection has a smaller cross section than the boiler return manifold. The in relation to the Heizkreisanschlüssen larger cross sections of boiler flow collector and boiler return manifold provide here for a lower flow rate of the heat transfer medium and thereby avoid disturbing turbulences.

Also for the sake of avoiding disturbing turbulence is further provided that the flow Connection between the hydraulic separator and the boiler flow collector one has smaller cross-section than the boiler flow collector and that the fluid connection between the hydraulic diverter and the boiler return manifold a smaller cross section than the boiler return manifold having.

Further is for the cascade unit in terms of dimensioning of flow cross sections preferably provided that the fluid connection between the hydraulic switch and the boiler flow collector a cross section that is larger than or as tall as the cross section of the passage between the flow area and the soft core area of the hydraulic switch is and that the fluid connection between the hydraulic switch and the boiler return manifold one Has cross-section that is greater than or as large as the cross section of the passage between the return area and the soft core portion of the hydraulic switch. Through this Tuning the cross sections is achieved in particular that the flow the heat transport medium in the cascade unit preferred through the fluid connections between the hydraulic switch on the one hand and the boiler return manifold on the other and the Kessen forerunner on the other hand flows, but not in an undesirable manner through the soft core area, as long as balanced volume flows in the boiler circuits and in the heating circuit. So that, for example, we have an immediate return of heated heat transfer medium from the boiler feeds avoided in the boiler returns. Likewise will avoided that cooled heat transport medium from the heating circuit return directly into the heating circuit flow arrives.

A particularly rational production and stable construction of the cascade unit can be achieved in that the mechanical connections between the or each boiler flow collector and the or each boiler return manifold on the one hand and the hydraulic switch on the other hand welded joints. Such welding ver Bindings are easy to produce, with both a manual and an automatic execution of the welding operations is possible. At the same time, the welded joints also provide the necessary sealing of fluid connections between the parts of the cascade unit.

alternative there is a possibility that the mechanical and fluid Connections between the or each boiler flow collector and the or each boiler return manifold on the one hand and the hydraulic Soft on the other hand are flange connections. This execution offers the advantage that the parts of the cascade unit for themselves can be transported and the assembly only at the installation site can be done. This is especially for a particularly large Cascade unit of advantage, since these are then divided into smaller parts is, in each case easier to transport and are manageable as the complete cascade unit. In operation of the Cascade unit are their parts via the flange connections but mechanically strong and liquid-tight with each other connected.

Farther is for the cascade unit according to the invention preferably provided that the boiler flow collector and the boiler return manifold same Have length and that the hydraulic switch a length that is smaller than or as long as the length of boiler flow collector and boiler return manifold is. Especially for smaller cascade units, that is for cascade units for example two to four Boiler, the hydraulic switch preferably has a length that the length of boiler flow collector and boiler return manifold equivalent. For cascade units for a larger one The number of boilers is sufficient, the boiler return manifold and the boiler flow collector with a correspondingly larger Length run while the hydraulic Soft can have or retain a shorter length. Thus, the production of the cascade unit is further simplified, since they use a single version of the hydraulic Soft or with few designs of hydraulic Switch for different boiler numbers.

Around the cascade unit for the intended service time reliable and to keep tight, are preferably the hydraulic switch, the or the boiler feed headers and the boiler return manifold (s) Profile or bending parts made of steel or coated steel or Stainless steel.

to Simplification of the structure of the cascade unit in a boiler room proposes the invention that the cascade unit on the underside or top and bottom mounting brackets for feet having. The only underside arrangement of mounting brackets is for cascade units appropriate, the only used in one orientation; in cascade units, which are usable in two different arrangements by Rotate the cascade unit by 180 ° about a horizontal Transverse axis are set, are top and bottom mounting brackets suitable for feet. The feet can be beneficial together with the cascade unit initially loose to the site the cascade unit are delivered; there are the feet then connected as needed to the cascade unit. It can the feet in their height or length be adjustable to accommodate different installation situations wear.

A further embodiment of the cascade unit according to the invention is characterized in that the cascade unit on the upper side or top and bottom mounting brackets for one or comprises a plurality of boiler support frames. In this version If required, the cascade unit can be supported by one or more boilers be equipped, with each boiler support frame one or can carry several boilers. An assembly of carrying frames or Boilers on a wall of a boiler room is no longer required, because the boilers can be advantageous means one or more boiler support racks with position the cascade unit are connected. This is the installation a heating system simplified and from the spatial Conditions of a boiler room made independent.

Since heating systems have different numbers and different arrangements of boilers, the cascade unit according to the invention can be manufactured and kept in a corresponding number of designs. With a relatively small number of designs, this is still sufficiently economical. If particularly many different cascade units are in demand, it may be advantageous according to a further embodiment of the invention that the cascade unit in modular design consists of a basic cascade module with a hydraulic switch and with at least one boiler flow collector and boiler return manifold and that the cascade basic module at its from Heizkreisvorlaufanschluss and Front end facing away from the heating circuit return connection has at least one connecting flange, via which a cascade expansion module can be connected to the basic cascade module, which has at least one respective boiler flow collector and boiler return manifold, but no hydraulic switch. In the modular design, the cascade unit can be adapted to different numbers and arrangements of boilers by the cascade unit either only the basic cascade module or additionally or multiple cascade extension modules, each of which can be joined together as needed. Only the basic cascade module requires the hydraulic switch, while the cascade extension modules can be designed more simply, in particular without a hydraulic switch.

In a preferred further embodiment provides that the cascade extension module two Having front ends, each with at least one connecting flange. Thus, the cascade extension module may be at its from the cascade base module turned away front end again with another cascade extension module be connected in the same way as the first cascade extension module with the cascade basic module.

The Cascade unit according to the invention is used in the first place Line to several boiler circuits of a heating system with a Heating circuit flow connection and a heating circuit return connection connect the heating system while maintaining the function of a hydraulic To provide a switch. Alternatively, the before described cascade unit as a heating circuit manifold for a heating system with two or more heating circuits used, the Boiler connections used as heating circuit connections and the heating circuit connections as boiler connections be used. In this second use then the in a boiler heated heat transfer medium distributed on two or more heating circuits, and here too the function a hydraulic switch is provided.

Except in a heating system, the inventive Cascade unit can also be used in a refrigeration system. In a first use while several refrigerators connected to a refrigeration circuit; in a second use becomes a cold generator with several cooling circuits connected.

in the Below, embodiments of the invention are based on explained a drawing. The figures of the drawing show:

1 a cascade unit for two boilers in a first embodiment in perspective view,

2 the cascade unit in a second embodiment, also for two boilers, in a perspective view with separate individual parts,

3 the cascade unit in a modular design for four boilers, in perspective view,

4 the cascade unit in a further embodiment for two pairs of back-to-back boilers and in modular design, in perspective view,

5 the left front end of the cascade unit 4 in a sectional perspective view,

6 the cascade unit in a further embodiment, for two pairs of back-to-back boilers, in perspective view,

7 the cascade unit off 6 in a second, rotated position in perspective view,

8th a hydraulic separator with heating circuit supply connection and heating circuit return connection, in a perspective view as part of a cascade unit,

9 the cascade unit in a further embodiment for two boilers, in perspective view,

10 the cascade unit off 9 with a cut off left frontal end region, also in perspective view,

11 a hydraulic switch in one opposite the 10 modified version, as part of the cascade unit, in perspective, on the top side partly broken view,

12 the cascade unit in a further embodiment, for four boilers arranged in series, in perspective view,

13 the cascade unit off 12 in a modified version,

14 the cascade unit in an embodiment for two pairs of back-to-back boilers, with mounting brackets, in perspective view,

15 the cascade unit off 14 with a connected to the mounting brackets boiler support frame, in an amended perspective view, and

16 the cascade unit in a last version, for two juxtaposed boiler, in perspective view.

In some drawing figures of the drawing, the various ports are the cascade unit 1 provided with code letters. Be indicates "HV" heating circuit flow connection, "HR" heating circuit return connection, "KV" boiler flow connection and "KR" boiler return connection.

1 shows a first embodiment of a cascade unit 1 for a heating system, here with two boilers, which are not shown. The cascade unit 1 includes as essential parts a boiler flow collector 3 , a boiler return manifold 4 and a hydraulic switch 5 , The boiler forerunner 3 , the boiler return manifold 4 and the hydraulic switch 5 are each designed as rectangular tube sections and run parallel to each other and in the in 1 shown operating position of the cascade unit 1 horizontal. The cross section of the hydraulic switch 5 here is flat-rectangular, with the two flat sides of the switch 5 are vertically aligned. Flush with the upper edge of the hydraulic switch 5 is at the viewer facing flat side of the boiler flow collector 3 arranged. Flush with the lower edge of the hydraulic switch 5 is with this the boiler return manifold 4 connected. There is between the boiler flow collector 3 and the boiler return manifold 4 a distance, whereby an immediate thermal contact between the boiler flow collector 3 and the boiler return manifold 4 , which would lead to an undesirable heat transfer, is avoided.

At the boiler forerunner 3 are two boiler feed connections 32 intended; at the boiler return manifold 4 are two boiler return connections 42 intended. With these connections 32 and 42 are the headers and return lines of the two boilers not shown here connected via pipes.

With the in 1 right, first front end 50.1 the hydraulic switch 5 are vertically one above the other a Heizkreisvorlaufanschluss 55 and a heating circuit return connection 56 connected to which the pipes of one of the boilers to be supplied with heat energy heating circuit are connectable.

The boiler forerunner 3 and the boiler return manifold 4 stand inside the cascade unit 1 in an in 1 invisible way with the hydraulic switch 5 and with the heating circuit supply connection 55 or heating circuit return connection 56 in fluid communication.

During operation of an associated heating system, the boilers produce warm heat transport medium, usually water, via the boiler feed header 3 merged and to the heating circuit flow connection 55 is directed. Cooled heat transfer medium flowing back from the heating circuit passes through the heating circuit return connection 56 and the hydraulic switch 5 into the boiler return manifold 4 , which redistributes the heat transport medium to the boilers for reheating.

As soon as the volume flows of the heat transfer medium are not balanced between the boiler circuits on the one hand and the heating circuit on the other hand, results in the area of the hydraulic switch 5 a compensation flow.

To the cascade unit 1 to be able to set up in a boiler room are at the cascade unit 1 here two feet apart from each other at a distance from each other 7 appropriate. At the top of the cascade unit 1 are two mounting brackets 17 provided, which also for attaching the feet 7 can serve. These mounting brackets 17 are then used when the cascade unit 1 according to 1 instead of, as shown in the drawing, with right-facing heating circuit flow and Heizkreisrücklaufanschlüssen 55 . 56 , with heating circuit supply and heating circuit return connections pointing to the left 55 . 56 is used. The cascade unit 1 according to 1 is designed to be symmetrical in such a way that, after rotation about a horizontal, transversely to the longitudinal direction of the cascade unit 1 extending axis of rotation 19 180 ° an unchanged arrangement of the boiler connections 32 and 42 has, in which case only the function of flow and return is reversed. The feet 7 can then contact the in 1 top mounting brackets 17 be attached to the cascade unit 1 even in the turned upside down position.

As the 1 vividly shows, has the cascade unit 1 a very compact form that greatly simplifies logistics from manufacturing to installation in a boiler room. Also, the manufacture and attachment of a thermal insulation is in this cascade unit 1 particularly easy due to their compact design.

2 shows the cascade unit 1 in a second embodiment in a perspective view with separate parts. In the left part of the 2 is the hydraulic switch 5 partially broken. In the right part of the 2 are the boiler forerunner 3 and the boiler return manifold 4 shown.

The hydraulic switch 5 again consists of a flat-rectangular pipe section, the flat sides are vertically aligned and have a height H5. At the in 2 left frontal end 50.1 the switch 5 are the heating circuit supply connection 55 and the heating circuit return connection 56 arranged. Inside the hydraulic switch 5 goes from the first front end 50.1 a separation wall 51 pointing towards the second front end 50.2 extends and at a distance from this second front end 50.2 ends. The partition 51 separates a lead-in area above it 53 the switch 5 from a lying below her return area 54 the switch 5 , The area to the right of the free end of the partition 51 is a soft core area, which is fluid between the flow area 53 and the return area 54 lies.

Above the free end of the partition 51 is a blind 57 in the switch 5 arranged. Between the lower edge of the panel 57 and the free end of the partition 51 becomes a defined passage 58.1 formed, which has a flow connection between the flow area 53 and the soft core area 52 forms. Below the free end of the partition 51 is a passage without an aperture 58.2 that the kernel core area 52 with the return area 54 in the interior of the switch 5 combines.

At the viewer facing flat side of the switch 5 are near the first front end 50.1 one fluid connection each 63 and 64 in the form of openings provided with congruently arranged fluid connections 63 in the boiler forerunner 3 and 64 in the boiler return manifold 4 in the assembled state of the cascade unit 1 interact. Due to the fluid connection 63 the heat transfer medium comes out of the boiler flow collector 3 in the lead area 53 the switch 5 and from there through the heating circuit supply connection 55 in the heating circuit. Cooled heat transfer medium flowing back from the heating circuit passes through the heating circuit return connection 56 in the return area 54 the switch 5 and from this by the fluid connection 64 in the return manifold 4 , From there, the heat transport medium is again supplied to the boilers, not shown here for heating.

As already mentioned, the hydraulic switch has 5 a height H5. The boiler forerunner 3 has a height H3 and the boiler return manifold 4 has a height H4. The sum of the heights H3 and H4 is smaller than the height H5, resulting in flush and flush mounting of boiler flow collector 3 and boiler return manifold 4 at the hydraulic switch 5 between collectors 3 and distributors 4 gives a clear distance.

When operating a heating system with the cascade unit 1 the volume flows of the heat transfer medium in the boiler circuits on the one hand and in the heating circuit on the other hand are not balanced, that is not equal, results over the Weichenkernbereich 52 the switch 5 a compensation flow through the passages 58.1 and 58.2 , As a result, for example, a lack of heat transfer medium in the boilers do not occur.

3 shows an embodiment of the cascade unit 1 in a modular design, the cascade unit 1 in 3 is designed for four boilers. Here is the cascade unit 1 from a basic cascade module 10 and a cascade extension module 11 together.

The cascade basic module 10 essentially corresponds to the cascade unit 1 , in the 1 is shown and described. The difference is that in the cascade basic module 10 in 3 at the of the Heizkreisvorlauf- and Heizkreisrücklaufanschlüssen 55 and 56 remote lying ends of boiler flow collector 3 and boiler return manifold 4 a connecting flange 13 is appropriate. With the connecting flange 13 is an arrangement of another boiler flow collector 3 and boiler return manifold 4 that together make up the cascade extension module 11 form, connected. The two boiler flow collectors 3 from basic module 10 and expansion module 11 are about the flange connection 13 Also connected fluidly, as well as the two boiler return manifold 4 from basic module 10 and expansion module 11 , The connecting flanges at the free end of the cascade unit are each equipped with a flange cover 13 ' tightly closed.

The hydraulic switch 5 Here is just part of the basic cascade module 10 ; the cascade extension module 11 does not need its own or additional hydraulic switch.

At the observer facing the front of the boiler flow collector 3 and boiler return manifold 4 are each alternating boiler flow connections 32 and boiler return connections 42 attached, so here a total of four boilers with the cascade unit 1 can be connected.

Bottom are with the cascade unit 1 several feet 7 connected, here under the basic cascade module 10 two feet 7 are provided while under the cascade extension module 11 only one stand 7 is provided. Each symmetrical to the feet 7 are at the top of the cascade basic module 10 and the cascade extension module 11 again mounting brackets 17 provided for the alternative attachment of the feet 7 serve when the cascade unit 1 in a 180 ° around a horizontal, transverse to the longitudinal direction of the cascade unit 1 extending axis of rotation rotated position is used. Again, the rotation of the cascade unit leads 1 only to ensure that the heating circuit flow and the heating circuit return connection 55 . 56 instead of as in 3 shown, after turn left, then turn right.

The 4 and 5 show an embodiment of the cascade unit 1 in which the essential parts are detachable with each other to the cascade unit 1 are connected.

The cascade unit 1 includes in the example according to 4 and 5 again the hydraulic switch 5 , Notwithstanding the previous examples are here with the hydraulic switch 5 two boiler flow collectors 3 and two boiler return manifolds 4 connected. Here are the connections between the boiler flow collectors 3 and the hydraulic switch 5 and between the boiler return manifolds 4 and the hydraulic switch 5 via flange connections 12 prepared, which are solvable if necessary.

The hydraulic switch 5 has seen here in cross section the shape of a flat, upright rectangle. The boiler forerunners 3 and the boiler return manifolds 4 have a substantially square cross-section, again with the sum of the heights of boiler flow collector 3 and boiler return manifold 4 smaller than the height of the hydraulic switch 5 , Thus, here too, the boiler flow collector 3 and the boiler return manifolds 4 have a distance between them without them on the top or bottom side of the hydraulic switch 5 protrude. In addition, and unlike the previous embodiments, in the cascade unit 1 according to the 4 and 5 also a clear distance between the boiler flow collectors 3 and the boiler return manifolds 4 on the one hand and the hydraulic switch 5 provided on the other hand. Thus, there is any unwanted heat exchange between the different parts of the cascade unit 1 practically completely prevented.

In the 4 each lying on the right front ends of each pair of boiler flow collector 3 and boiler return manifold 4 are with a connecting flange 13 equipped to modularly design one or more cascade expansion modules that are incorporated in 4 not shown to be able to start.

5 shows in a rotated perspective view of the cut end portion of the cascade unit 1 out 4 , reducing the location of the fluid connections 63 and 64 becomes clear. The fluid connections 63 connect the hydraulic switch 5 with the boiler flow collectors 3 and the connections 64 connect the hydraulic switch 5 with the boiler return manifolds 4 , The fluid connections 63 and 64 lie respectively inside the flange connections 12 ,

The 6 and 7 show a cascade unit 1 in two different perspective views showing the symmetry of this cascade unit 1 clarify.

The cascade unit 1 also has a hydraulic switch here 5 , which consists of a cross-sectionally flat-rectangular and upright pipe section. At the first front end 50.1 are the heating circuit supply connection 55 and the heating circuit return connection 56 arranged one above the other. On the top of the hydraulic switch 5 is a single boiler forerunner 3 with four top boiler inlet connections. With the lower edge of the hydraulic switch 5 Two boiler return manifolds are flush on their front and back 4 arranged, each having only two boiler return connections.

Like a comparison of 6 and 7 clarified, the cascade unit can 1 by rotating about a vertical, transverse to the longitudinal direction of the cascade unit 1 extending axis of rotation 19 from a version with left-side heating circuit connections 55 and 56 ( 6 ) in a version with heating circuit connections on the right side 55 and 56 (please refer 7 ). The boiler flow connections to the boiler flow collector 3 and the boiler return connections on the two boiler return manifolds 4 are arranged so that even after rotation about the axis of rotation 19 180 ° results in an identical connection diagram.

The hydraulic switch 5 is built inside according to the examples described above.

8th shows a modified embodiment of the hydraulic switch as a single part of a cascade unit in a perspective view. In this example of the switch 5 is at the first front end 50.1 only the heating circuit return connection 56 appropriate. The heating circuit supply connection 55 here goes from the viewer facing away, rear flat side of the hydraulic switch 5 off and then over a 90 ° bend in a direction parallel to the heating circuit return connection 56 guided. In this version, so the heating circuit flow connection 55 and the heating circuit return connection 56 not vertically over each other, but with a small vertical offset next to each other.

Further shows the example of the switch 5 in 8th a possible embodiment of the fluid connections 63 and 64 to the boiler flow collector, not shown here 3 or boiler return manifold 4 , The fluid connections 63 and 64 are here each as rectangular openings in the viewer facing side of the switch 5 executed and of a frame-like Surrounded by jetty. With this frame-like bridge the turnout attacks 5 in the collectors not shown here 3 and distributors 4 a, which in addition to the flow connection and a mechanical connection is created. For sealing is useful a weld.

The 9 and 10 show a further embodiment of the cascade unit 1 , which is again designed for two boilers. The hydraulic switch 5 Here, too, consists of a pipe section with a flat-rectangular cross-section, but now the two flat sides of the hydraulic switch 5 are aligned horizontally. Again, at the first end facing the viewer 50.1 the switch 5 the heating circuit supply connection 55 and the heating circuit return connection 56 appropriate. At the bottom of the switch 5 are two feet 7 appropriate.

On the top of the hydraulic switch 5 lie parallel and at a distance from each other, the boiler flow collector 3 and the boiler return manifold 4 , both of which are each designed as a rectangular tube section with approximately square cross-section.

The horizontal transverse to the longitudinal direction of the cascade unit 1 measured width B5 of the hydraulic switch 5 is greater than the sum of the horizontal and transverse to the longitudinal direction of the cascade unit 1 measured widths B3 of collectors 3 and B4 from distributor 4 , Thus, there is a side edge flush arrangement of collector 3 and distributors 4 on the hydraulic switch 5 between collectors 3 and distributors 4 a free distance.

The boiler supply connections 32 are here on top of the boiler forerunner 3 appropriate; with longitudinal offset are the boiler return connections 42 on the top of the boiler return manifold 42 arranged.

Because in 10 the left end of the cascade unit 1 Here is the view into the interior of the cascade unit 1 free. Here it becomes visible that, as already described above, the hydraulic switch 5 in its interior through the partition 51 in a flow area 53 and a return area 54 is divided. In the here not visible rear, that is right part of the hydraulic switch 5 ends the partition 51 , whereby here the Weichenkernbereich 52 is formed.

Furthermore, the shows 10 a part of the fluid connection 63 between the boiler forerunner 3 and the lead-in area 53 the switch 5 ,

11 shows a hydraulic switch 5 as part of a cascade unit in a perspective, partially broken-away representation. The hydraulic switch 5 Here again consists of a flat-rectangular tube section, whose flat sides are aligned horizontally. At the left front end 50.1 are again the heating circuit supply connection 55 and the heating circuit return connection 56 arranged side by side.

Again, the interior of the hydraulic switch 5 in a flow area 53 , a return area 54 and a soft core area 52 divided. However, this subdivision is not done here by the previously described partition, but by a pipe socket 51 ' , The pipe socket 51 ' goes from the first front end 50.1 from the heating circuit return connection 56 extends and extends this far into the interior of the switch 5 into until close to the second, in 11 right front end 50.2 the switch 5 ,

In addition to the pipe socket 51 ' is inside the switch 5 a panel 57 ' arranged substantially the upper half of the cross section of the interior of the switch 5 covered. This will be below the aperture 57 ' a passage 58 ' educated. The area to the left of the panel 57 ' is thus the lead area 53 the switch 5 , The area right from the free end of the pipe socket 51 ' is the return area 54 the switch 5 and in the longitudinal direction of the switch 5 The central area seen is the soft core area 52 ,

In the top of the switch 5 are still the two fluid connections 63 and 64 to the boiler flow collector and boiler return manifold not shown here visible. The connection 63 goes thereby from the Vorlaufbereich 53 out; the connection 64 lies in the return area 54 the switch 5 ,

On the underside are again two feet 7 with the switch 5 connected.

The boiler forerunner 3 and the boiler return manifold 4 are used to complete the cascade unit in the same way as in 9 and 10 on top of the switch 5 arranged.

The 12 and 13 show two further embodiments of the cascade unit, for which it is characteristic that two side walls facing each other 31 and 41 from boiler forerunner 3 and boiler return manifold 4 are each wavy and parallel to each other and spaced executed. This creates the possibility of the boiler flow connections 32 and the boiler return connections 42 on a common straight line on top of the cascade unit 1 to arrange.

The hydraulic switch 5 forms the lower part of the cascade unit 1 , The soft 5 is formed by a flat-rectangular pipe section, the flat sides are horizontal. The heating circuit supply connection 55 and the heating circuit return connection 56 are at the first front end 50.1 the switch 5 appropriate. The collector 4 and the distributor 4 lie side by side on top of the switch 5 and point to each other in the area of their undulating walls 31 and 41 a clear distance.

In the example in 12 can have four boilers with the cascade unit 1 get connected. The hydraulic switch 5 has in the longitudinal direction of the cascade unit 1 seen the same length as the boiler forerunner 3 and the boiler return manifold 4 , Thus lies the second front end 50.2 the wheat 5 flush with the ends of collectors 3 and distributors 4 ,

In the example below 13 has the hydraulic switch 5 a length that is less than the length of boiler feed header 3 and boiler return manifold 4 in the example shown about 50%. Thus lies the right front end 50.2 the switch 5 approximately in the area of the longitudinal center of the collector 3 and distributors 4 Under these.

Also in the example in 13 is the cascade unit 1 designed for four boilers. By using the shorter hydraulic switch 5 Material and manufacturing costs are saved, without the function of the hydraulic switch 5 Smears have to be made.

Also with the two examples after the 12 and 13 are at the bottom of the cascade unit 1 two feet each 7 intended for installation in a boiler room.

The 14 and 15 show an embodiment of the cascade unit 1 to which associated boilers can be supported.

14 initially only shows the cascade unit 1 , which has a structure here, essentially the structure of the cascade unit 1 according to 4 and 5 equivalent. The only difference is that in the cascade unit 1 to 14 the two boiler forerunners 3 and the two boiler return manifolds 4 each fixed, so not on connecting flanges, with the hydraulic switch 5 are connected.

Near the two ends of the cascade unit 1 are on this top two mounting brackets 18 attached to the attachment of a boiler support frame 8th according to 15 serve. At the boiler support frame 8th can in the example after 15 all in all 4 Heating boilers are attached hanging, with two pairs of boilers are arranged back to back. Accordingly, at the cascade unit 1 at the two collectors 3 and the two distributors 4 a total of four pairs of boiler feed connections 32 and boiler return connections 42 intended. The hydraulic switch 5 corresponds in structure and function to the basis of 2 described switch 5 ,

To set up in a boiler room serve here again two feet 7 that under the cascade unit 1 are attached.

16 Finally, an example of a cascade unit is shown 1 , where not only the boiler flow collector 3 and the boiler return manifold 4 each have a clearance, but these also each to the hydraulic switch 5 are spaced. In this embodiment of the cascade unit 1 Heat loss through heat conduction is largely avoided. The hydraulic switch 5 the cascade unit 1 according to 16 can the hydraulic switch 5 correspond in the 11 was shown and explained. The fluid connections 63 and 64 between the hydraulic switch 5 on the one hand and the boiler forerunner 3 and the boiler return manifold 4 On the other hand, they are designed so that they simultaneously assume a distance function. At each of the fluid connection 63 respectively. 64 opposite end of collector 3 and distributors 4 will be the desired distance to the hydraulic switch 5 by means of a spacer 59 causes, which also forms a mechanical connection.

Under the cascade unit 1 are again two feet 7 attached to the installation.

Due to the clear distances between collectors 3 and distributors 4 and soft 5 can with a thermal insulation of the cascade unit 1 Also, the interstices filled with insulating material, resulting in both a very good thermal separation of collector 3 , Distributor 4 and soft 5 can be reached from each other and a good thermal insulation to the outside with a simple shaping of the insulation.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20211303 U1 [0002]

Claims (31)

Cascade unit ( 1 ) for a heating system with two or more boilers, the cascade unit ( 1 ) at least one each in the operating state horizontally extending boiler flow collector ( 3 ) and boiler return manifold ( 4 ), the boiler forerunner ( 3 ) and the boiler return manifold ( 4 ) each with prepared boiler connections fitted for a group of two or more boilers ( 32 . 42 ) for connecting the boiler feeders and the boiler returns, the cascade unit ( 1 ), a hydraulic switch ( 5 ), which on the one hand with the boiler flow collector ( 3 ) and boiler return manifold ( 4 ) and on the other hand with at least one heating circuit flow connection ( 55 ) and heating circuit return connection ( 56 ) is fluidly connected, and wherein the collector ( 3 ) and the distributor ( 4 ) and the hydraulic switch ( 5 ) are mechanically connected to a prefabricated unit, characterized in that - the hydraulic switch ( 5 ) in the operating state horizontally and parallel to the boiler flow collector ( 3 ) and boiler return manifold ( 4 ) and - that the boiler forerunner ( 3 ) and the boiler return manifold ( 4 ) spaced apart and with the hydraulic switch ( 5 ) are mechanically connected. Cascade unit according to claim 1, characterized in that the heating circuit supply connection ( 55 ) and the heating circuit return connection ( 56 ) both at a first end ( 50.1 ) of the hydraulic switch ( 5 ) are arranged. Cascade unit according to claim 1 or 2, characterized in that the or each boiler flow collector ( 3 ) and the or each boiler return distributor ( 4 ) and the hydraulic switch ( 5 ) are each formed by a rectangular tube section. Cascade unit according to claim 3, characterized in that it includes a boiler feed collector ( 3 ) and boiler return manifold ( 4 ) that the hydraulic switch ( 5 ) has a height (H5) which is greater than the added heights (H3 and H4) of boiler flow collectors ( 3 ) and boiler return manifold ( 4 ), and that the boiler forerunner ( 3 ) and the boiler return manifold ( 4 ), preferably on the outside edge, at the front or the rear of the hydraulic separator ( 5 ) are arranged. Cascade unit according to claim 3, characterized in that it includes a boiler feed collector ( 3 ) and boiler return manifold ( 4 ) that the hydraulic switch ( 5 ) rectangular tube section has a width (B5) which is greater than the added widths (B3 and B4) of boiler flow collector ( 3 ) and boiler return manifold ( 4 ), and that the boiler forerunner ( 3 ) and the boiler return manifold ( 4 ), preferably on the outside edge, at the top or the bottom of the hydraulic switch ( 5 ) are arranged. Cascade unit according to claim 3, characterized in that it includes a boiler feed collector ( 3 ) and boiler return manifold ( 4 ) that the hydraulic switch ( 5 ) rectangular tube section has a height (H5) equal to or greater than the height (H4) of the boiler return manifold ( 4 ) is that the boiler return manifold ( 4 ), preferably flush with the lower edge, at the front or rear of the hydraulic separator ( 5 ) and that the boiler forerunner ( 3 ), preferably flush-edged, at the top of the hydraulic switch ( 5 ) is arranged. Cascade unit according to claim 3, characterized in that it comprises a boiler feed collector ( 3 ) and two boiler return manifolds ( 4 ) that the hydraulic switch ( 5 ) has a height (H5) equal to or greater than the height (H4) of each boiler return manifold ( 4 ) is that the boiler return manifold ( 4 ), preferably at the edge of the recess, at the front and the rear of the hydraulic switch ( 5 ) and that the boiler feed collector ( 3 ), preferably flush-edged, at the top of the hydraulic switch ( 5 ) is arranged. Cascade unit according to claim 3, characterized in that it comprises two boiler feed collectors ( 3 ) and boiler return manifold ( 4 ) that the hydraulic switch ( 5 ) rectangular tube section has a width (B5) which is greater than the added widths (B3 and B4) per a boiler lead collector ( 3 ) and boiler return manifold ( 4 ), that the boiler forerunners ( 3 ) in each case, preferably on the outside edge, at the top or the bottom of the hydraulic separator ( 5 ) and that the boiler return manifolds ( 4 ) in each case, preferably flush with the outer edge, on the underside or the upper side of the hydraulic separator ( 5 ) are arranged. Cascade unit according to claim 3, characterized in that it comprises two boiler feed collectors ( 3 ) and boiler return manifold ( 4 ), that the rectangle pipe section forming the hydraulic separator has a height (H5) which is greater than the added heights (H3 and H4) of each one boiler advance collector ( 3 ) and boiler return manifold ( 4 ), that the boiler forerunners ( 3 ), preferably flush with the top or bottom edges, laterally on both sides of the hydraulic switch ( 5 ) are arranged and that the boiler return manifolds ( 4 ), preferably lower or upper edge flush, laterally on both sides of the hydraulic switch ( 5 ) are arranged. Cascade unit according to claim 1 or 2, characterized in that the hydraulic switch ( 5 ) is formed by a rectangular tube section and that the boiler forerunner ( 3 ) and the boiler return manifold ( 4 ) are formed by two parallel pipe sections, whose sides facing each other by a wave or zigzag wall ( 31 . 41 ) are formed, wherein the two wave or zigzag walls ( 31 . 41 ) parallel and spaced apart. Cascade unit according to one of claims 1 to 10, characterized in that the boiler feed collector ( 3 ) and the hydraulic switch ( 5 ) are mechanically connected to each other mechanically and that the boiler return manifold ( 4 ) and the hydraulic switch ( 5 ) are connected to one another in a planar manner against each other mechanically. Cascade unit according to one of claims 1 to 10, characterized in that the boiler feed collector ( 3 ) and the hydraulic switch ( 5 ) are mechanically connected to one another at a distance between their mutually facing surfaces and that the boiler return manifold ( 4 ) and the hydraulic switch ( 5 ) are mechanically interconnected at a distance between their facing surfaces. Cascade unit according to one of claims 1 to 12, characterized in that the boiler connections ( 32 . 42 ) for connecting the boiler feeders and the boiler returns to the cascade unit ( 1 ) are arranged symmetrically in such a way that after a rotation of the cascade unit ( 1 180 ° about a transverse to the longitudinal direction of the cascade unit ( 1 ) horizontal or vertical axis of rotation ( 19 ) is an identical arrangement to the output arrangement of the boiler connections ( 32 . 42 ), but the heating circuit supply connection ( 55 ) and the heating circuit return connection ( 56 ) at the other end of the cascade unit ( 1 ) come to rest. Cascade unit according to one of claims 1 to 13, characterized in that the hydraulic switch ( 5 ) a lead area ( 53 ), a return area ( 54 ) and a soft core region ( 52 ), these areas ( 52 . 53 . 54 ) are fluidly connected to each other, wherein the core core region ( 52 ) fluidly between flow area ( 53 ) and return area ( 54 ) and where the lead-in area ( 53 ) in terms of flow with the boiler flow collector ( 3 ) and the return area ( 54 ) in terms of flow with the boiler return manifold ( 4 ) connected is. Cascade unit according to claim 14, characterized in that the subdivision of the hydraulic switch ( 5 ) by a partition wall ( 51 ) formed from the first front end ( 50.1 ) of the hydraulic switch ( 5 ) between heating circuit supply connection ( 55 ) and heating circuit return connection ( 56 ) starting in the direction of the second front end ( 50.2 ) of the hydraulic switch ( 5 ) and at a distance from the second front end ( 50.2 ) of the hydraulic switch ( 5 ) ends. Cascade unit according to claim 15, characterized in that at or close to the second end ( 50.2 ) of the hydraulic switch ( 5 ) facing end of the partition ( 51 ) an aperture ( 57 ) with a passage ( 58.1 ) between the lead area ( 53 ) and the soft core region ( 52 ) is arranged. Cascade unit according to claim 14, characterized in that the subdivision of the hydraulic switch ( 5 ) through a pipe socket ( 51 ' ) formed from the first front end ( 51 ) of the hydraulic switch ( 5 ) either from the heating circuit supply connection ( 55 ) or from the heating circuit return connection ( 56 ) starting in the direction of the second front end ( 50.2 ) of the hydraulic switch ( 5 ) and at a distance from the second front end ( 50.2 ) ends. Cascade unit according to claim 17, characterized in that at a distance from the first end ( 50.1 ) of the hydraulic switch ( 5 ) an aperture ( 57 ' ) with a passage located in a lower course area ( 58 ' ) between the lead area ( 53 ) and the soft core region ( 52 ) is arranged. Cascade unit according to one of claims 1 to 18, characterized in that the fluid connection ( 63 ) between the hydraulic switch ( 5 ) and the boiler forerunner ( 3 ) and the fluid connection ( 64 ) between the hydraulic switch ( 5 ) and the boiler return manifold ( 4 ) in each case by outwardly sealed congruent openings in abutting or facing surface areas of hydraulic switch ( 5 ) on the one hand and boiler flow collectors ( 3 ) and boiler return manifold ( 4 ) are formed on the other hand. Cascade unit according to one of claims 1 to 19, characterized in that the heating circuit flow connection ( 55 ) has a smaller cross-section than the boiler feed header ( 3 ) and that the heating circuit return connection ( 56 ) has a smaller cross section than the boiler return manifold ( 4 ) having. Cascade unit according to one of the claims 1 to 20, characterized in that the fluid connection ( 63 ) between the hydraulic switch ( 5 ) and the boiler forerunner ( 3 ) has a smaller cross-section than the boiler feed header ( 3 ) and that the fluid connection ( 64 ) between the hydraulic switch ( 5 ) and the boiler return manifold ( 4 ) has a smaller cross section than the boiler return manifold ( 4 ) having. Cascade unit according to claim 16 or 18, characterized in that the fluid connection ( 63 ) between the hydraulic switch ( 5 ) and the boiler forerunner ( 3 ) has a cross section which is greater than or as large as the cross section of the passage ( 58.1 . 58 ' ) between the lead area ( 53 ) and the soft core region ( 52 ) of the hydraulic switch ( 5 ) and that the fluid connection ( 64 ) between the hydraulic switch ( 5 ) and the boiler return manifold ( 4 ) has a cross section which is greater than or as large as the cross section of the passage ( 58.2 ) between the return area ( 54 ) and the soft core region ( 52 ) of the hydraulic switch ( 5 ). Cascade unit according to one of claims 1 to 22, characterized in that the mechanical connections between the or each boiler flow collector ( 3 ) and the or each boiler return manifold ( 4 ) on the one hand and the hydraulic switch ( 5 ) On the other hand are welded joints. Cascade unit according to one of claims 1 to 22, characterized in that the mechanical connections between the or each boiler flow collector ( 3 ) and the or each boiler return manifold ( 4 ) on the one hand and the hydraulic switch ( 5 ) on the other hand flange connections ( 12 ) are. Cascade unit according to one of claims 1 to 24, characterized in that the boiler feed collector ( 3 ) and the boiler return manifold ( 4 ) have the same length and that the hydraulic switch ( 5 ) has a length which is less than or equal to the length of boiler feeders ( 3 ) and boiler return manifold ( 4 ). Cascade unit according to one of claims 1 to 25, characterized in that the hydraulic switch ( 5 ), the boiler forerunner (s) ( 3 ) and the boiler return manifold (s) ( 4 ) Are profile or bending parts made of steel or coated steel or stainless steel. Cascade unit according to one of Claims 1 to 26, characterized in that the cascade unit ( 1 ) underside or top and bottom mounting brackets ( 17 ) for feet ( 7 ) having. Cascade unit according to one of Claims 1 to 27, characterized in that the cascade unit ( 1 ) top or top and bottom mounting brackets ( 18 ) for one or more boiler presses ( 8th ) having. Cascade unit according to one of Claims 2 to 28, characterized in that it has a modular design from a cascade basic module ( 10 ) with a hydraulic switch ( 5 ) and with at least one boiler advance collector ( 3 ) and boiler return manifold ( 4 ) and that the basic cascade module ( 10 ) at its from heating circuit supply connection ( 55 ) and heating circuit return connection ( 56 ) facing away from the front end ( 50.2 ) at least one connecting flange ( 13 ) with which the cascade basic module ( 10 ) a cascade expansion module ( 11 ), which at least one each boiler lead collector ( 3 ) and boiler return manifold ( 4 ), but no hydraulic switch. Cascade unit according to claim 29, characterized in that the cascade extension module ( 11 ) two front ends, each with at least one connecting flange ( 13 ) having. Use of the cascade unit ( 1 ) according to one of claims 1 to 27 as a heating circuit manifold for a heating system with two or more heating circuits, wherein the boiler connections ( 32 . 42 ) are used as Heizkreisanschlüsse and the Heizkreisanschlüsse ( 55 . 56 ) can be used as boiler connections.