EP1834134A2

EP1834134A2 - Integrated hydraulic unit

Info

Publication number: EP1834134A2
Application number: EP05826383A
Authority: EP
Inventors: Renato Vaiani
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-12-28
Filing date: 2005-12-19
Publication date: 2007-09-19
Also published as: WO2006070282A3; ITBO20040821A1; WO2006070282A2

Abstract

An integrated hydraulic unit comprising a thermal circuit (2) which can be connected to heating means for heating an operating fluid and for sending the operating fluid heated by the heating means to at least one user device; a sanitary circuit (4) for heating a fluid and an expansion tank for the operating fluid.

Description

Integrated hydraulic unit

Technical Field

The present invention relates to an integrated hydraulic unit. In particular, the present invention relates to an integrated hydraulic unit comprising a thermal circuit which can be connected to heating means (a boiler) for heating an operating fluid and for sending the heated operating fluid to at least one user device, such as one or more radiators, and/or a sanitary circuit for heating a fluid by means of a heat exchanger.

Background Art

Hydraulic units are known which heat a fluid for sanitary use, for example water from the water supply system, using the heat of the thermal circuit fluid which will supply the radiators or heaters. In the prior art, said heating is generally achieved using a heat exchanger which is activated at the moment when the supply of hot water is required. More particularly, when the supply of hot water is required, which is normally supplied at temperatures not higher than 55°C, the water in the sanitary circuit is heated by the heat exchanger which is temporarily supplied, and therefore activated, with the thermal circuit heated operating^" fluid, which is usually at a temperature of around 8O⁰C.

The thermal, or primary, circuit also comprises a separate expansion tank, which must be connected with the system circuitry to provide the necessary capacity for volumetric expansion in the presence of the thermal expansions of the fluid.

The hydraulic units in the prior art have the disadvantage of installation that is normally complex, which must be planned in each case depending, for example, on the boiler used and the expansion tank available and they have a thermal circuit fluid flow rate of around 0.6 - 0.8 mVh, not enough for the new generation of condensing boilers.

Moreover, the hydraulic units in the prior art are not able to promptly and immediately supply hot water to the sanitary circuit. This disadvantage is due to the fact that a predetermined initial transient is needed to be able to overcome the thermal lag of the heat exchanger and bring the heat exchanger up to temperature with the thermal circuit heated operating fluid.

The heat exchanger is activated at the moment when the supply of hot water from the sanitary circuit is required, therefore, necessitating an interval of time to reach the operating temperature and be able to heat the water supply system water.

Said interval of time is directly proportional to the time which elapses between one request for hot water and the next request.

Disclosure of the Invention

In this context, the main technical need of the present invention is to propose an integrated hydraulic unit which is free of the above-mentioned disadvantages.

In particular, the aim of the present invention is to provide an integrated hydraulic unit which allows immediate installation, a thermal fluid flow rate of 2 mVh and preferably a prompt and immediate supply of sanitary circuit heated fluid.

Another aim of the present invention is to propose an integrated hydraulic unit able to supply sanitary circuit heated fluid each time it is required, irrespective of the time which elapses between one request and the next. The technical need indicated and the aims specified are substantially achieved by an integrated hydraulic unit comprising the technical features described in one or more of the claims herein.

Brief Description of the Drawings

Further features and advantages of the present invention are more apparent in the detailed description below, with reference to a preferred, non-limiting, embodiment of an integrated hydraulic unit, illustrated in the accompanying drawings, in which:

Figure 1 is a front view of an integrated hydraulic unit in accordance with the present invention; Figure 2 is a cross-section according to plane II - II of the integrated hydraulic unit illustrated in Figure 1;

Figure 3 is a perspective view of a boiler to which the integrated hydraulic unit illustrated in Figure 1 can be connected; Figure 4 is a cross-section according to plane IV - IV of the boiler illustrated in Figure 3.

Detailed Description of the Preferred Embodiments of the Invention With reference to Figures 1 and 2, the numeral 1 denotes as a whole an integrated hydraulic unit according to the present invention.

The function of the hydraulic unit 1 is to heat the water arriving from a water supply system (not illustrated) drawing energy, in the form of heat, from an operating fluid which supplies one or more radiators which heat one or more rooms.

The hydraulic unit 1 comprises a thermal circuit 2 which can be connected to heating means (not illustrated) for heating an operating fluid and for sending the operating fluid heated by the heating means to at least one user device (not illustrated) ; at least one heat exchanger 3 acting on a section 2a of the thermal circuit 2 and a sanitary circuit 4 for heating a sanitary circuit 4 fluid by means of the heat exchanger 3.

It should be noticed that the sanitary circuit fluid consists of water from a sanitary water supply system or of any fluid which must be heated before being supplied for sanitary or food use.

In particular, as illustrated in Figure 1, the sanitary circuit 4 comprises at least a first connection 5 for connecting to a water supply system, connected, as is better described below, to a second connection 6 for connecting to one or more user devices (not illustrated) and the supply of heated water.

As illustrated in Figure 1, the thermal circuit 2 comprises a delivery connection 8 which sends the operating fluid heated by the heating means to the user device or devices, for example radiators or heaters, for heating one or more rooms, connected to the heating means in the known way to receive heated operating fluid from them.

A first pipe 9 extends from the delivery connection 8 and reaches an outlet 10 to connect the circuit 2 to the end user devices.

Moreover, the thermal circuit 2 comprises return means 11 which receive the operating fluid that returns from the user devices and will be heated again by the heating means. The return means 11 also comprise a pipe 13 which carries the operating fluid towards the heating means or boiler.

According to the invention, circulation of the operating fluid in the thermal circuit 2 and in the heat exchanger 3 is guaranteed by circulating means 23 located, in the preferred embodiment illustrated in Figure 1, on the return means 11/13. The circulating means 23 comprise at least a hydraulic pump 24, preferably electric, located on the return means 11 pipe 13. As illustrated in Figure 2, the circulating means 23 also comprise an expansion tank 25, operatively located upstream and physically below the hydraulic pump 24, comprising a tank 26 which acts as a compartment for the primary waters and connection with the operating fluid returning from the user devices and travelling to the heating means. The tank 26 is pressurised by an inert gas, for example nitrogen, which is kept physically separate from the operating fluid by a diaphragm or membrane 27. The function of the expansion tank is to compensate for variations in the volume of the operating fluid due to increases and reduction in the temperature of the circuit and of the user system, so that the pressure in the thermal circuit 2 remains almost constant.

Advantageously, with the technical solution described, the thermal and sanitary circuits and the expansion tank of the hydraulic unit 1 are integrated in a single containment body 28. Moreover, in a preferred embodiment, the hydraulic unit 1 comprises storage means 15 for preheating a quantity of the sanitary circuit 4 fluid. In particular, the storage means 15 are connected to the sanitary circuit 4 to store heated fluid. Advantageously, for this purpose, the heat exchanger 3 acts on the storage means 15.

More specifically, the storage means 15 comprise a tank 16 made of a metal material which is in direct contact with the heat exchanger 3. The tank 16 is connected to the second connection 6 of the sanitary circuit 4 so that it can promptly supply sanitary circuit 4 heated fluid. In this way, the heat exchanger 3, which is selectively activated, keeps the water in the metal tank 16 at a predetermined temperature, at least when the heat exchanger 3 is activated.

The sanitary circuit 4 water reaches the predetermined temperature by passing, before it fills the tank 16, in contact with the hot parts of the exchanger 3, for example of the plate type.

The latter, which as indicated can be selectively activated, can be switched between an activated condition, in which it is supplied with the thermal circuit 2 heated operating fluid and a deactivated condition in which it is not supplied. In particular, the heat exchanger 3 is selectively supplied by diverter means 18 located on the delivery means 7, which divert at least part of the heated operating fluid flowing through the delivery means 7. As illustrated in Figure 1, the diverter means consist for example of a diverter valve, connected between the primary pipe 9 of the delivery means 7 and a heat exchanger 3 inlet 20, for supplying the heat exchanger 3 with thermal circuit 2 heated operating fluid and introducing it into a pipe 21 connected between a heat exchanger 3 outlet 22 and the recirculation pump 24.

The diverter valve 18 is preferably controlled by a control unit (not illustrated) for switching the heat exchanger 3 between the activated and deactivated positions.

In practice, when the hydraulic unit 1 is started up, the thermal circuit 2 sends heated operating fluid, through the delivery means 7, at a temperature of between 50 and 8O⁰C to the user devices (radiators or heaters) .

Advantageously, the first time the system is started up the diverter valve 18 is switched so that at least part of the heated operating fluid passes through the heat exchanger 3. The latter heats the fluid present in the sanitary circuit 4 and in particular in the storage means 15 to a temperature of between 40 and 55°C. The fluid contained in the storage means 15 is therefore at a working temperature which allows it to be promptly supplied if required by a user device.

When the fluid contained in the storage means 15 reaches the required temperature, if no water is required from the sanitary circuit, the diverter valve 18 is switched so that it inhibits the passage of heated operating fluid through the heat exchanger 3 and optimises (primary) heating system efficiency.

It must be emphasised that the fluid contained in the storage means 15 remains at a temperature of between 40 and 55°C, that is to say at a temperature ready for its supply, even if its supply is not required for a lengthy period.

Indeed, because the hydraulic unit is integrated in the containment body 28, the delivery means 7, in which the thermal circuit heated operating fluid flows, allow the temperature of the storage means 15 to be kept at the temperature ready for supply, by means of conduction.

Moreover, the operating fluid returning from the user devices enters the return means 11 at a temperature of between 40 and 60⁰C, contributing, for the reasons indicated above, to maintaining the fluid contained in the storage means 15 at the temperature ready for supply.

The unit 1 may also comprise:

- a pressure switch 30 for the water arriving at the primary circuit;

- one or more water heating probes 31 for the primary and secondary circuits;

- a valve 32 for loading nitrogen in the tank 25;

- an air relief valve 33;

- a selector 34 for manual/automatic supply;

- a connection 35 for safety valves; - a sanitary circuit flow regulator 36;

- a bypass 37 on the primary circuit; a thermostatic valve with flow rate limiter in the sanitary circuit.

In operation, the primary circuit water enters through the return delivery means 11, floods the expansion tank 26, in which the membrane 27 elastically follows the expansion of the fluid countered by the opposing pressure of the nitrogen, is recalled through the suction hole by the circulation pump 24 and sent to the boiler through the outlet 13.

From the boiler heated water arrives at the inlet 8 which, in the heating mode, exits the outlet 10, follows the heating system circuit and returns (obviously less hot than when it came out of the boiler) through the inlet 11.

Otherwise, in the mode for production of water for the sanitary circuit, part or all of the water passes through the heat exchanger 3 and returns to the pump 24 through the pipes 22, 21. In the sanitary circuit, the water enters through the connection 5, passes through the heat exchanger 3 and exits through the connection 6 passing through the thermostatic valve

(which contributes to system energy saving, by minimising the outflow of sanitary water when the temperature is too low for use) , the flow rate regulator (whose function is to stabilise the flow rate of the sanitary water, making it independent of the inlet pressure available) creating the storage in the metal tank

16 in contact with the exchanger.

With reference to Figures 3 and 4, an example of a boiler 100 to which the hydraulic unit 1 may be applied is described, although it shall be understood that different types of boilers may also be used.

The boiler 100 is preferably a condensing boiler, that is to say, a boiler which also uses the latent heat from condensation of the water vapour contained in the combustion products to heat an operating fluid.

The boiler 100 comprises a cylindrical body 101, having an outer surface 101a and an inner surface 101b, into which a burner, not illustrated, fixed to the upper closure sends combustion fumes. It should be noticed that, in the trade, the term combustion fumes refers to the products in the gaseous phase of the redox process carried out by the burner. The cylindrical body 101 comprises, inside it and transversalIy to its longitudinal axis, a separator plate 102 for separating the combustion chamber and the outlet for the fumes.

The cylindrical body 101 also comprises a plurality of ring- shaped chambers 103 positioned on the outer surface 101a and communicating with one another through channels 104. One ring- shaped chamber 103a of the plurality of ring-shaped chambers 103 comprises an inlet section 105 which can be connected to a return pipe (not illustrated) for the operating fluid arriving from the plurality of radiators (not illustrated) . The ring-shaped chamber 103a comprising the inlet section 105 is located in a lower portion 101c of the cylindrical body 101.

In the inner surface 101b, the cylindrical body 101 has a helical pipe 106 communicating with a ring-shaped chamber 103b at the top of the plurality of ring-shaped chambers 103.

The helical pipe 106 comprises an outlet section 107 located close to the lower portion 101c of the cylindrical body 101. The outlet section 107 can be connected to a pipe for delivering a heated operating fluid to a plurality of radiators. According to this configuration, the return means 13, described above, of the hydraulic unit 1 may be connected to the inlet section 105 of the pipe in the ring-shaped chambers 103 to heat the thermal circuit fluid.

The delivery means 7 may be connected to the outlet section 107 to send the thermal circuit heated operating fluid to the user devices and/or to the heat exchanger 3.

The boiler 100 also comprises a cup-shaped body 108 connected with a snap-lock fit to the lower portion 101c of the cylindrical body 101 and an upper closure again connected with a snap-lock fit to the upper portion 101b.

The cup-shaped body 108 comprises an exhaust pipe 109 for the combustion fumes and a discharge pipe or tap 110 for emptying out condensation from the combustion fumes.

In particular, the exhaust pipe 109 is located on the side of the cup-shaped body 108 and the discharge pipe 110 which can be angled as required is located at the centre of a lower portion emptied out by gravity.

The upper closure comprises a central hole where the combustion unit not illustrated is fixed.

Advantageously, the relative angle between the cylindrical body 101, the cup-shaped body 108 and the upper closure with the combustion unit may be varied as required during boiler assembly through 360° independently of one another, to allow easy connection of the delivery, return and fume exhaust pipes to the boiler 100. Advantageously, as illustrated in Figures 3 and 4, the boiler 100 also comprises a helical tube 111 inserted coaxially inside the helical pipe 106 and held in the required position with a spacer. The helical tube 111 comprises an inlet section 112 coaxial with the outlet section 107 of the helical pipe for receiving sanitary circuit fluid. The helical tube 111 also comprises an outlet section 113 located close to the top ring- shaped chamber 103b, for supplying sanitary circuit heated fluid. In this configuration, the heat exchanger 3 does not have to be present as described above, in the integrated hydraulic unit 1. In this case, the function of the heat exchanger 3 is performed by the helical tube 111. In practice, the boiler 100 heats the thermal circuit operating fluid which enters through the inlet section 105 of the ring-shaped chambers 103, passing along the longitudinal extension of the boiler as far as the ring-shaped chamber 103b, where it is connected to the helical pipe 106. The helical tube 111, held in place by the spacer coaxial with the helical pipe 106, is also heated to the same temperature, bringing the sanitary circuit fluid to the temperature ready for supply. Moreover, since the helical tube 111 extends over the entire longitudinal extension of the cylindrical body 101, it has a capacity such that it can act as storage means for the heated fluid. The sanitary circuit heated fluid is then supplied when required through the outlet section 113 of the helical tube 111.

It should be noticed that in this case the sanitary circuit heated fluid remains at the above-mentioned temperature because the helical pipe 106, inside which the helical tube 111 is present, continues to receive heat from the combustion fumes to continue supplying the radiators.

The invention is described with reference to preferred embodiments, although equivalent modifications may be made without it thereby departing from the scope of the inventive concept.

Claims

1. A hydraulic unit comprising a thermal circuit (2) which can be connected to heating means for heating an operating fluid and for sending the operating fluid heated by the heating means to at least one user device; a sanitary circuit (4) for sending a heated fluid to at least one user device; an expansion tank (25) located in the thermal circuit (2), wherein the thermal and sanitary circuits (2, 4) and the expansion tank (25) are integrated in a single body (28) .

2. The hydraulic unit according to claim 1, comprising at least a heat exchanger (3) which can be switched, on command, to perform a heat exchange between the operating fluid and the sanitary fluid.

3. The hydraulic unit according to claim 1 or 2, comprising sanitary fluid storage means (15) .

4. The hydraulic unit according to claim 3, wherein the heat exchanger (3) acts on the storage means (15) .

5. The hydraulic unit according to claim 3 or 4, wherein the storage means (15) comprise a tank (16) made of a metal material which is in thermal contact with the heat exchanger (3) .

6. The hydraulic unit according to one or more of the foregoing claims, comprising circulating means (23, 24) for the operating fluid.

7. The hydraulic unit according to claim 6, comprising diverter means (18, 20, 22, 21) for supplying the heat exchanger (3) by diverting at least part of the heated operating fluid towards the circulating means (23, 24) .

8. The hydraulic unit according to claim 7, wherein the diverter means comprise a diverter valve (18) connected to a heat exchanger (3) inlet (20) and a pipe (21) connected between a heat exchanger (3) outlet (22) and the circulating means (23) .

9. The hydraulic unit according to claim 8, wherein the diverter valve (18) is controlled by a control unit for switching the heat exchanger (3) between the activated position and the deactivated position.

10. The hydraulic unit according to claim 6, wherein the circulating means (23) comprise a hydraulic pump (24) .

11. The hydraulic unit according to one or more of the foregoing claims, wherein the expansion tank (25) comprises a tank (26) for the operating fluid and a separation membrane (27) .

12. A condensing boiler, comprising a cylindrical body (101), having an outer surface (101a) and an inner surface (101b) for condensing fumes, inside which there extends a helical pipe (106) for the passage of an operating fluid subject to heat exchange with the flame of a burner, the boiler being characterised in that the cylindrical body (101) also comprises a plurality of ring- shaped chambers (103) located on the outer surface (101a), being connected with the pipe (106) and communicating with one another through channels (104) for the passage of the operating fluid subject to heat exchange with the condensing fumes.

13. The boiler according to claim 12, also comprising a second helical pipe (111) with an inlet and outlet (112, 113) outside the boiler, the pipe being inserted coaxially inside the helical pipe (106) for the passage of a second operating fluid subject to heat exchange with the first operating fluid.

14. The boiler according to claim 12 or 13, also comprising a cup-shaped body (108) connected in such a way that it can be angled to the lower portion of the cylindrical body (101) and an upper closure also connected in such a way that it can be angled with a snap-lock fit to the upper portion (101b) of the cylinder (101) .

15. The boiler according to claim 14, comprising a discharge pipe (110) for emptying out the condensation from the combustion fumes, being connected to the cup-shaped body (108) in such a way that it can be angled as required.