EP2942583B1

EP2942583B1 - Enbloc support body for a hydraulic valve group for use in a wall-mounted boiler

Info

Publication number: EP2942583B1
Application number: EP15166662.5A
Authority: EP
Inventors: Remo Spaggiari; Mirko Bacchini
Original assignee: Otma SNC Di Spaggiari & C
Current assignee: Otma SNC Di Spaggiari & C
Priority date: 2014-05-06
Filing date: 2015-05-06
Publication date: 2017-08-23
Anticipated expiration: 2035-05-06
Also published as: EP2942583A1; DK2942583T3

Description

The present invention mainly relates to an enbloc support body for a hydraulic valve group for use in a wall-mounted boiler.
The present invention relates, furthermore, to a hydraulic valve group that uses an enbloc support body made according to the teachings of the present invention.
Moreover, a further object of the present invention is to provide a wall-mounted boiler provided with at least one hydraulic valve group comprising at least one enbloc support body according to the teachings of the present invention.
As known, the hydraulic groups for wall-mounted combined boilers developed in recent years have undergone considerable rationalization of the hydraulic components with the progressive abandonment of individual single-function components mutually connected by means of pipes, in favor of ever more compact multifunctional control and safety devices, which have been designed to perform all the hydraulic functions of the boiler.
Currently, with the use of only three valve devices, in combination with a secondary plate heat exchanger, substantially the hydraulic lay-out of the boiler is defined. The three valve devices are:

a centrifugal pump valve device
a delivery valve device; and
a return valve device.

The valve device of the centrifugal pump substantially comprises an inlet connection arranged on a degassing chamber, an outlet connection arranged on a body volute casing that contains the centrifugal impeller and an electric motor.
In turn, the delivery valve device substantially comprises a rear double connection for the secondary heat exchanger and two connections, respectively, for the primary circuit (delivery) and for the secondary circuit (sanitary hot water outlet).
And finally, the return valve device substantially comprises a rear double connection for the secondary heat exchanger and two connections, respectively, for the primary circuit (return) and for the secondary circuit (sanitary cold water inlet). The secondary plate heat exchanger for the production of conventional type sanitary hot water also used as hydraulic bar, comprises two separate circuits in countercurrent with four terminal connections arranged on the same plane defining the inlet and the outlet of the primary circuit and of the secondary circuit respectively; supply and return valve devices are assembled on these four connections.
On the valve device of the centrifugal pump the air vent valve, the three-way-valve-diverter, the safety valve, the connection for connecting with the expansion tank and the connection for the manometer can be integrated.
Normally, on the delivery valve device, the three-way-valve-diverter, the differential bypass valve, and the pressure switch can be integrated.
In ordinary use, on the return valve body the flow sensor (flow switch) for controlling the sanitary withdrawal, the plant feeding tap and the plant drainage tap can be integrated.
These additions on the valve bodies typically involve the development of custom designs.
The continuous research aimed at reducing the production cost of boilers and to reduce the overall dimensions of the same (configuring the latter more and more like household appliances) has also introduced the use of composite materials (polymers) instead of brass parts used previously.
It has been noted, however, that the arrangement of the various control and security components as described above requires high investments in equipment and molds, with amortization times rather long and not very compatible with the product lifecycles that tend to be increasingly shorter.
The need, therefore, to limit investment with an important reduction of the overall cost for making the product, has lead to seek constructive solutions that would imply in a further reduction of the boiler hydraulic group thus obtaining only one multifunctional body that would integrate all the hydraulic functions of the boiler by using a single valve body in association with the conventional type plate heat exchangers and with a conventional type centrifugal pump.
Document EP-A1-0 652 408 (BERETTA A ING SPA) discloses an enbloc support body for a hydraulic valve group for use in wall-mounted combined boilers according to the preamble portion of claim 1.
Therefore, main object of the present invention is to provide a hydraulic valve for extremely compact wall-mounted boilers and whose constituent elements are reduced to a single multifunction valve body integrating all the preset control and safety devices, by means of rapid connections, for coupling with a conventional type secondary plate heat exchanger and for coupling with a conventional type centrifugal circulation pump both being easily available on the market.
The present invention will now be described with reference to the accompanying drawings, which illustrate examples of nonlimiting embodiments with the notice that, given the particular complexity of the drawings and the high number of details, not all elements have been numbered; wherein:

Figure 1 illustrates a tentative hydraulic diagram of a gas wall-mounted boiler in which an enbloc support body is used according to the teachings of the present invention;
Figure 2 schematically shows an enlargement of a first embodiment of the enbloc support body inserted in a hydraulic valve group for wall-mounted boilers;
Figure 3 schematically illustrates an enlargement of a second embodiment of the enbloc support body inserted in a hydraulic valve group for wall-mounted boilers;
Figure 4 shows a rear isometric view of an assembly comprising an innovative type hydraulic valve group combined with a respective centrifugal pump and with a respective plate heat exchanger;
Figure 5 illustrates a front axonometric view of an assembly comprising an innovative type hydraulic valve group (with some elements removed) combined with a respective centrifugal pump and with a respective plate heat exchanger;
Figure 6 shows a rear view in orthographic projection of the assembly of Figure 5;
Figure 6A illustrates a SECTION AA performed on the assembly of Figure 6;
Figure 6B illustrates a SECTION BB performed on the assembly of Figure 6;
Figure 6C illustrates a SECTION CC performed on the section shown in Figure 6B;
Figure 7 shows an exploded three-dimensional assembly of Figures 5, 6;
Figure 8 illustrates an axonometric view of an enbloc support body made according to the teachings of the present invention;
Figure 9 shows a rear front view of the enbloc support body of figure 8;
Figure 10 illustrates a top plan view of the enbloc support body of figure 8;
Figure 11 shows a bottom view of the enbloc support body of figure 8;
Figure 12 illustrates a right side view of the enbloc support body of figure 8;
Figure 13 shows a left side view of the enbloc support body of figure 8; and
Figure 14 illustrates a front frontal view of the enbloc support body of figure 8.

In figure 1, 10 denotes, as a whole, a combined autonomous plant for room heating and for producing sanitary hot water.
As we will see, in this autonomous plant 10 an enbloc support body for a hydraulic valve group made according to the teachings of the present invention is integrated.
Plant 10 comprises a wall-mounted boiler 11 and a hydraulic network 12 hydraulically connected one with the other.
The hydraulic network 12, in turn, comprises, in a known manner, a primary heating circuit (C1) and a secondary circuit (C2) wherein the hot water flows.
The primary circuit (C1) comprises a hot water delivery duct 50 towards at least one heating element (ER), and a cold water return duct 51 towards the wall-mounted boiler 11.
Associated to the secondary circuit (C2) is instead at least one dispenser body (tap or mixer) (RB) of hot water.
As shown in Figure 1, gas wall-mounted boiler 11 comprises:

an atmospheric gas burner 13 (to which a gas supply line (LG) controlled by a safety gas valve (VV) is associated);
one main heat exchanger 14;
a chimney (CHM), provided with a fan (VT), to evacuate the fumes produced by the gas combustion;
a cold water delivery duct 15 towards the main heat exchanger 14 for heating cold water;
a return duct 16 from the main heat exchanger 14 of the heated hot water;
a secondary heat exchanger 17, of the "plate" type; take note that, while the water circulating in main heat exchanger 14 is heated directly by the heat produced by the atmospheric gas burner 13, in the secondary heat exchanger 17 a heat exchange between the hot water coming from the main heat exchanger 14 and the sanitary cold water coming from the water supply (AQ) through a duct 18 occurs; the secondary heat exchanger 17 is activated by a request for sanitary hot water, detected by a flow switch 19, by a user who has opened the withdrawal tap (RB);
a hydraulic valve group 20 hydraulically connected with the secondary heat exchanger 17; and
a centrifugal pump group 21 hydraulically connected with the hydraulic valve group 20.

In a first embodiment illustrated in Figure 1 (and in the enlargement of figure 2), the centrifugal pump group 21 comprises, in turn, an electric motor 22 which rotates a rotor 23 in turn enclosed in a pump body 24.
The pump body 24 is in hydraulic communication with a degassing chamber 25 provided with a respective air vent 26. Instead, in a second embodiment shown in Figure 3, a hydraulic valve group 20*, in addition to comprising all the above mentioned elements in the first embodiment (Figures 1, 2), also integrates a degassing chamber 25* provided with a respective air vent 26*.
Therefore, in the configuration of Figure 3 a traditional centrifugal pump group 21* is used, i.e. provided with an electric motor 22* and with a pump body 24* containing the impeller 23* only, without degassing chamber 25* and air vent valve 26* (which now, as we said, are integrated in the hydraulic valve group 20*).
In both embodiments illustrated in Figures 2, 3, the hydraulic valve group 20, 20* comprises, in addition to a respective enbloc support body 27, 27* the following devices:

an expansion vessel 28;
a high pressure switch 29 of the primary heating circuit (C1);
a three-way-valve-diverter 30 (in which an electric motor 31 is provided, which in turn drives a respective shutter (OTT) also subjected to the action of a helical spring (ML)); take note that, at least partially, the three-way-valve-diverter 30 is integrated in the enbloc support body 27, 27*;
the flow switch 19 for sanitary cold water, which is also at least partially integrated in the enbloc support body 27, 27*;
a feeding tap 32 of the primary heating circuit (C1);
a safety valve 33 of the primary circuit (C1) which, when needed, sends the drainage water through a drainage duct 34;
a drainage tap 35 for the plant always through the aforementioned drainage duct 34;
a manometer 37; and
a by-pass valve 38.

It can be seen how the hydraulic valve group 20, 20* is used as an apparatus for the regulation of the water flow to/from the wall-mounted boiler 11, in which the hydraulic valve group 20, 20* itself is inserted.
In greater detail, and in particular with reference to the accompanying figures 8-14, the enbloc support body 27 comprises a main body 27A, obtained in one piece, in which the following elements are integrated:

a joint 27B for the above mentioned expansion tank 28;
a joint 27C for the maximum pressure switch 29 of the primary heating circuit (C1);
a seat 27D for the three-way-valve 30; as known, the three-way-valve 30 (sanitary water priority) is used to activate the sanitary water step of the boiler by diverting the flow on the path 60 of the secondary heat exchanger 17;
a seat 27E for the sanitary cold water flow switch (19);
two joints 27F*, 27F** for the feeding tap 32 of the primary heating circuit (C1);
a joint 27G for the safety valve 33 of the primary heating circuit (C1);
a joint 27H for the drainage tap 35 of the plant;
a joint 27I for the centrifugal pump group 21;
a joint 27L with the water supply (AQ); by observing Figure 6 it can be understood that said joint 27L is also adapted to house a filter 40 and a flow rate limiter 41;
a joint 27M with the primary heating circuit (C1);
two joints 27N, 27P for the connection with the plate heat exchanger 17 (Figures 1 and 5);
a seat 27Q (Figure 6B) for the bypass valve 38;
a joint 27R for the manometer 37; and
a duct 27S (Figure 6C) for the hydraulic connection of the secondary heat exchanger 17 (in particular of the joint 27N) with the seat 27D of the three-way-valve 30.

To structurally reinforce the enbloc support body 27 a consolidation plate 27T is used (Figures 6 and 6C) obtained in one piece with the rest of the elements forming the enbloc support body 27 itself.
As shown in more detail in Figures 2, 6C, 7, the three-way-valve 30 comprises a diverter plug (OTT), which, actuated by the electric motor 31 in contrast with the spring (ML), is adapted to alternately close either a way 27M* relative to the joint 27M (Figure 6C) (sanitary hot water priority), or a way 27M** (room heating step, Figure 2), while leaving open the way 27M*** of hydraulic communication with the suction duct 27I of the centrifugal pump group 21 (Figure 2).
Take note also (figure 7) that the three-way-valve 30 is completed by a motor-holder cartridge 30A which supports the electric motor 31 for actuating the three-way-valve 30 itself. In actual use, inside the motor-holder cartridge 30A the rod 30B of the shutter (OTT) has entered.
In Figure 6A the application of the feeding tap 32 of the water (coming from the water supply (AQ)) to the enbloc support body 27 has been shown.
In particular, as illustrated for instance in Figure 6A the feeding tap 32 comprises a knob 32A by means of which it is possible to operate the rod with the respective shutter 32B.
Shutter 32B is astride two ducts 32C and 32D obtained in the body of the feeding tap 32. Each duct 32C, 32D is hydraulically connected to a respective joint 27F*, 27F**.
When it is necessary to fill the primary circuit (C1) with water coming from the water supply (AQ) it is sufficient to unscrew the knob 32A, so that the downward displacement of the shutter 32B enables hydraulic communication of the two ducts 32C, 32D. After loading the primary circuit (C1) with the water of the water supply (AQ) the tap 32 may then be closed by tightening the knob 32A.
As illustrated in Figure 1, 2, 3, in a known manner, in the hydraulic network 12, in addition to the delivery duct 15 and to the return duct 16 also the following ducts are provided:

the cited delivery duct 50 (of the primary heating circuit (C1)) of the hot water towards the heating element (ER); the delivery duct 50 is provided with a zone valve (VZ) which is arranged in the vicinity of the heating element (ER);
a return duct 51 (of the primary heating circuit (C1)) of the cold water from the heating element (ER); and
an outlet duct 52 of the sanitary hot water from the plate heat exchanger 17; by means of the duct 52 is fed to the tap (RB).

Take note, also, that inside the secondary plate heat exchanger 17 it is possible to distinguish a path 60 of the heating water in the sanitary step, and a countercurrent path 70 of the sanitary water when the withdrawal from the dispensing tap (RB) is activated (Figure 1).
When the three-way-valve 30 is closed on way 27M** (heating step), if circulation blockage occurs in the primary circuit (C1) for the intervention of the zone valve (VZ), the bypass valve 38 is opened to ensure a minimum amount of recirculating water in the main exchanger 13 of the boiler 11 to safeguard the main exchanger 13 itself.
The operation of the plant 10 is fairly intuitive.
In the presence of a request for sanitary hot water (sanitary hot water priority step) due to the opening of the dispensing tap (RB), the electric motor 31 of the three-way-valve 30 pushes the shutter (OTT) closing against the way 27M* momentarily excluding the primary heating circuit (C1). The hot water produced in the main heat exchanger 13 is all directed through the secondary heat exchanger 17 to heat the sanitary cold water coming from the water supply (AQ) passing through it in the opposite direction.
At the end of the sanitary water withdrawal the room heating step is restored with the shutter (OTT) which reopens the way 27M*, and therefore the heating water is able to cover the entire primary circuit (C1).
The extreme compactness of the enbloc hydraulic valve body has as a corollary the possibility of using a single composite material, where for composite material it is meant a thermoplastic material, also called "polymer", that guarantees a good resistance to high operating temperatures conjugated to a low permeability of the absorption of water (hydrolysis).
The main advantage of the enbloc support body object of the present invention consists in providing rational provisions of the functional elements, with two rear connections for a plate heat exchanger and with two connections for connecting the return of the primary circuit and the cold water inlet of the secondary circuit.
All this translates into a significant reduction of the investment costs in molds and equipment in addition to a substantial reduction of the overall dimensions and a consequent reduction of production costs.

Claims

An enbloc support body (27, 27*) for a hydraulic valve group (20) for use in wall-mounted combined boilers (11) for room heating and sanitary hot water; said enbloc support body (27, 27*) integrating in a main body (27A), obtained in one piece, the following elements:
- a joint (20B) for an expansion vessel (28);

- a joint (27C) for a high pressure switch (29) of a primary heating circuit (C1);

- a seat (27D) for a three-way valve (30);

- a seat (27E) for a flow switch (19) of sanitary cold water (FS);

- a joint (27G) for a safety valve (33) of the primary heating circuit (C1);

- a joint (27I) for a centrifugal pump group (21);

- a joint (27L) for connection with a water supply (AQ);

- a joint (27M) for connection with said primary heating circuit (C12);

- two joints (27N, 27P) for a direct connection with a secondary plate heat exchanger (17);

- a seat (27Q) for a bypass valve (38);

- a joint (27R) for a manometer (37); and

- a hydraulic connection duct (27S) connecting one of said two joints (27N) for direct connection with said secondary plate heat exchanger (17) with said seat (27D) for said three-way valve (30);
said enbloc support body (27, 27*) being characterized in that it further integrates the following elements:
- two joints (27F*, 27F**) for a feeding tap (32) of the primary heating circuit (C1); and

- a joint (27H) for a plant drainage tap (35);
Enbloc support body (27, 27*), according to Claim 1, characterized in that it comprises a degassing chamber (25*) integrated with said remaining elements.
Hydraulic valve group (20) for use in a wall-mounted boiler (11) characterized in that it is provided with at least an enbloc support body (27, 27*) according to any one of Claims 1-2.
Wall-mounted boiler (11) characterized in that it is provided with at least a hydraulic valve group (20) according to Claim 3.