EP1590607A1

EP1590607A1 - Heating plant control device

Info

Publication number: EP1590607A1
Application number: EP03815723A
Authority: EP
Inventors: Umberto Bertolotti
Original assignee: IVAR SpA
Current assignee: IVAR SpA
Priority date: 2003-02-04
Filing date: 2003-02-04
Publication date: 2005-11-02
Anticipated expiration: 2023-02-04
Also published as: HUE030743T2; EP1590607B1; ES2606777T3; CN100441961C; WO2004070280A1; PT1590607T; CN1738994A; AU2003215889A1

Abstract

Regulating device (1) for heating systems comprising a first body (14) defining at least a first path (15) for a fluid, which extends at least from first inlet (15a) to a second outlet (15b), and a second path (16) for the fluid extending at least from a second inlet (16a) to a second outlet (16b), a second body (18) defining at least a third path (19) for the fluid, which extends at least from a third inlet (19a), connected to the first inlet (15b), to a third outlet (19b). It is provided for a re-circulation opening (17) so as to mix the fluid flowing in the second path (16) with the fluid flowing in the first path (15). The first inlet (15a) and the second outlet (16b) can be connected to a boiler or to a heating circuit (2) with high-temperature water, whereas the second inlet (16a) and the third outlet (19b) can be operatively connected to a heating circuit (3) with low-temperature water.

Description

"HEATING PLANT CONTROL DEVICE"

DESCRIPTION The present invention relates to a regulating device for heating systems. In particular, the invention relates to a device for regulating the flow of a fluid, usually hot water, in systems for heating rooms in houses, commercial or other buildings .

It is known that systems for heating buildings are mainly divided into high-temperature and low-temperature sys- terns. High-temperature systems substantially consist of a boiler, a series of heating elements, typically referred to as radiators, arranged in the various rooms of the building, and of a plurality of manifolds and ducts connecting the boiler to the heating elements. On the other hand, low-temperature systems consist of, beyond a boiler, a plurality of heating elements in the form of ducts generally placed under the room floor and of at least a pair of manifolds connecting the heating elements to the boiler. Whereas systems of the first type operate with water at a temperature of around eighty degrees centigrade, systems of the second type must necessarily operate with temperatures of around forty degrees, since higher temperatures might damage floorings. Moreover, it is known about mixed heating systems comprising a high- temperature circuit and a low-temperature circuit, which are suitably connected one to the other.

It is known about devices allowing to regulate in a suitable way the flow of hot water circulating within low- temperature systems, which can be used both when said systems are connected directly to a boiler, and when they are part of a mixed system and are therefore connected to a high-temperature system connected in its turn to the boiler.

Said devices enable to regulate the temperature within the low-temperature circuit and comprise a large number of components. Regulating devices generally comprise an inlet for high-temperature water (for instance from the boiler) , an intake for hot water in the low-temperature circuit, a return for water from the low-temperature circuit and an outlet for water towards the boiler. Said devices can comprise a thermostatic valve controlling the inlet for high-temperature water, a pump for circulating water, one or more outlet taps for water arranged in the lower portions of the ducts so as to empty the system when the latter is shut off for maintenance, and one or more relief valves arranged in the upper portions of the ducts so as to automatically expel air bubbles. Further- more, known regulating devices generally allow to mix a given amount of return water from the low-temperature circuit with hot water from the boiler, so as to suitably determine the temperature of water getting into the low- temperature circuit . In low-temperature systems it is further known about the use of a safety thermostatic switch that stops the system and blocks hot water from the boiler when water temperature within the system is above a pre-established maximum value (of around 50 degrees) .

Known regulating devices as described above have some drawbacks and disadvantages.

As a matter of fact, due to the need to suitably connect an extremely large number of components so as to obtain the desired operation, said devices always have a very complex and bulky structure .

Furthermore, said regulating devices generally consist of an extremely large number of parts, with many fittings and connections crossing each other following quite winding paths .

Such features result first of all in a great complexity of the device and in an increase of production, installation and maintenance costs . Moreover, it should be pointed out that installation and maintenance operations for said regulating devices are particularly complex, long and difficult.

Finally it should be pointed out that said devices are always extremely bulky, thus giving rise to further in- stallation problems, since they have to be housed in suitable casings arranged in the walls together with the manifolds of the heating system.

Under these circumstances the technical task underlying the present invention is to conceive a regulating device for heating systems that can substantially obviate the aforesaid drawbacks. Within said technical task an important aim is to conceive a regulating device for heating systems that has a simple and rational structure. Another aim of the present invention is to conceive a regulating device for heating systems that has a particularly small size and a compact structure. A further aim of the present invention is to provide for a regulating device for heating systems that can be easily carried out. Still another aim is to conceive a regulating device for heating systems that can be rapidly and easily installed. Another aim of the present invention is to provide for a regulating device for heating systems that is reliable and effi- cient . A further aim of the present invention is to conceive a regulating device for heating systems that has a high operating safety also in case of failure of some of its components. A still further aim of the present invention is to conceive a regulating device for heating sys- terns that enables an optimal temperature regulation in single domestic systems also in case of heating systems connected to a central or district heating. Further aims consist in carrying out a regulating device for heating systems that has particularly low manufacturing, instal- lation and maintenance costs. The technical task and the aims referred to above are achieved by means of a regulating device for heating systems having the characteristics described in the enclosed claims. The following contains by way of merely indicative and non-limiting example the description of a preferred though not exclusive embodiment of a regulating device for heating systems according to the invention, as shown in the enclosed drawings, in which: Figure 1 shows a detail of a heating system for rooms with a device according to the invention associated thereto;

Figure 2 is a side view of the system of Figure 1; - Figure 3 shows a perspective view of a regulating device for heating systems according to the present invention;

Figure 4 shows a front view of the device of Figure 3 ; Figure 5 shows a side view of the device of Figure 3 ; - Figure 6 shows a section of the device of Figure 3 along lines VI-VI;

Figure 7 shows a second section of the device of Figure 3 along lines VII-VII;

Figure 8 shows a view from below of the device of Fig- ure 3 ;

Figure 9 shows a third section of the device of Figure 3 along lines IX-IX;

Figure 10 shows a fourth section of the device of Figure 3 along lines X-X. In the present text, in accordance with the terminology used in the field, "low-temperature water" means water for heating rooms that is at a temperature of about 30-50 degrees, and more precisely of about 35-42 degrees, whereas "high-temperature water" means water supplied by a boiler or similar or circulating in a high-temperature system, which is at a temperature of about 80 degrees centigrade . With reference to the figures mentioned, a regulating de- vice for heating systems according to the invention is globally referred to with reference numeral 1. As can be seen in Figures 1 and 2, the device 1 is associated to a system for heating rooms, and in particular the device 1 is arranged between a high-temperature circuit 2 and a low-temperature circuit 3. The high- temperature circuit 2 comprises at least an intake manifold 4 and a return manifold 5 for hot water, to which a series of connecting ducts 6 are connected, connecting the manifolds 4, 5 to the single heating elements. In order to simplify the connection with the ducts 6 the manifolds 4, 5 are preferably arranged on two different levels . Figure 1 shows some conventional elements for heating circuits, such as brackets 7 for fastening the manifolds 4, 5 to a wall, outlet taps 8 for emptying the circuit 2 when the latter is shut off for maintenance, automatic relief valves 9 for removing air bubbles built within the circuit 2, and a pair of fittings 10 provided with clos- ing valves with corresponding manually operated taps. The high-temperature circuit 2 is connected to a boiler or other source of hot water (not shown in the figures) by means of such fittings 10. It should be pointed out that the device 1 could alternatively be connected directly in a wholly similar way to the boiler or other source of hot water, in case no high-temperature circuit 2 is present. Also the low-temperature circuit 3 comprises a water intake manifold 11 and a return manifold 12, operatively connected one to the other and to which corresponding heating elements are connected, typically pipes 13, which lead low-temperature water to the room to be heated and are typically arranged under the room floor. The circuit 3 is provided with a water intake point and with an outlet point for low-temperature water, which are connected to the regulating device 1.

Also said manifolds 11, 12 are fastened to a wall by means of brackets 7. The low-temperature circuit 3 is generally provided with suitable regulating elements 13a for the water flow introduced into each duct, which can be for instance manual, electric or thermostatic heads. The regulating device 1 is placed between the low- temperature circuit 3 and the high-temperature circuit 2, or the boiler, so as to suitably regulate the intake of high-temperature hot water into the low-temperature circuit 3. The regulating device 1 further enables to pre- ix high-temperature water coming from the boiler with a pre-established amount of low-temperature water taken from the low-temperature circuit 3.

The regulating device 3 comprises a first body 14 defining at least a first path 15, for instance a duct, for a fluid, typically water, which extends at least from a first inlet 15a, connected to the intake manifold 4 of the circuit 2 for high-temperature water or to the boiler, to a first outlet 15b. Said body 14 further comprises a second path 16 for the fluid extending at least from a second inlet 16a, connected to the return manifold 12 of the low-temperature circuit 3, to a second outlet 16b. The first path 15 is operatively connected to the second path 16 by means of a re-circulation opening 17, which allow to pre-mix a pre-established amount of low- temperature return water flowing within the second path 16 with the high-temperature inlet water flowing within the first path 15. Advantageously, the second outlet 16b is placed between the second inlet 16a and the re- circulation opening 17. The device 1 further comprises a second body 18 defining at least a third path 19 for the fluid, which extends at least from a third inlet 19a, operatively connected to the first outlet 15b, to a third outlet 19b, connected to the intake manifold 11 of the low-temperature heating circuit 3.

Furthermore, the second body 18 advantageously defines a fourth path 20 for the fluid, which path extends at least from a fourth inlet 20a, operatively connected to the second outlet 16b, to a fourth outlet 20b operatively connected to the return manifold 5 of the heating circuit 2 with high-temperature water or to the return line of the boiler. The fourth inlet 20a is connected to the second outlet 16b by means of a connecting duct 21. Alternatively, the second body 18 might comprise only the third path 19 and the second outlet 16b might be operatively connected directly to the high-temperature circuit 2 or to the boiler. Advantageously, the first inlet 15a and the second inlet 16a are placed in an opposed position with respect to the first body 14 and are substantially lined up. Preferably, the first outlet 15b has a longitudinal axis substantially perpendicular with respect to the axes of the first inlet 15a and of the second inlet 16a. Also the third outlet 19b and the fourth outlet 20b are advantageously placed in opposed position with respect to the second body 18 and are substantially lined up, and the third inlet 19a has a longitudinal axis substantially perpendicular with respect to the axes of the third 19b and of the fourth outlet 20b. The first 14 and the second body 18 are preferably carried out each as one piece, for instance as cast metal, but might also be carried out as several parts mounted together. The device 1 further comprises a pump 22 for circulating water, which is operatively arranged between the first outlet 15b and the third inlet 19a. It should be pointed out that the pump is schematically shown in sectioned view in Figures 6, 9 and 10 as a whole body, since it is known per se. Obviously, the pump is provided with a connection for the fluid between the first outlet 15b and the third inlet 19a, and with known means for pushing the fluid in the desired direction. As can be seen in Figures 3, 5 and 6, the first body 14 and the second body 18 are suitably arranged on different levels, the first body 14 correspond- ing to the level of the intake manifold 4 of the high- temperature circuit 2 and of the return manifold 12 of the low-temperature circuit 3, and the second body 18 corresponding to the level of the return manifold 5 of the high-temperature circuit 2 and of the intake manifold 11 of the low-temperature circuit 3. The first outlet 15b and the third inlet 19a are advantageously coplanar and therefore protrude from their respective bodies 14, 18, so as that the pump 22 can be easily mounted. The device 1 further comprises means 23 for varying the amount of water flowing from the second path 16 to the first path 15, which are operatively associated to the first body 14 on the re-circulation opening 17. Said means 23 are ad- vantageously adjustable so as to vary the flow rate of the return low-temperature water to be mixed with the high-temperature water coming from the first inlet 15a, so as to send to the third path 19 of the second body 18 and to the intake manifold 11 of the low-temperature cir- cuit 3 water suitably pre-mixed according to heating needs .

This allows not to introduce directly into the low- temperature circuit 3 high-temperature water, which might damage the system by causing sudden temperature rises in the circuit 3. Furthermore, it is thus possible to improve the efficiency of the system by re-circulating in the low-temperature circuit 3 a given amount of low- temperature water and adding only high-temperature water as strictly necessary. Said means 23 can for instance comprise a manually adjustable holder 23 so as to define the maximum potentiality of the low-temperature heating circuit 3. The device 1 further comprises means for regulating the water flow through the first inlet 15a, which are associated to the first body 14 within the first path 15. Said flow-regulating means 24 comprise a thermostatic head 24a, operatively active so as to actuate a shutter 24b placed in the first path 15 so as to vary the flow of high-temperature water entering the device 1. Said regulating means further comprise a sensor 24c placed within the third path 19 and operatively connected to the thermostatic head 14a, which can suitably regulate the amount of high-temperature hot water which is introduced into the device 1 and therefore into the low-temperature circuit 3 according to the temperature detected in the pre- mixed water entering the low-temperature circuit 3. As an alternative said flow-regulating means 24 can comprise an electric motor provided with suitable sensors and opera- tively active so as to actuate a holder arranged within the first path 15 so as to vary the flow of intake high- temperature water. The device, 1 can further comprise means for controlling the working of the device 1 (not shown in the figures because of their conventional shape) , operatively connected to the means 24 for regulating the intake flow. Such means can be conventional electromechanical or electronic control systems and can be connected to suitable means for controlling the working of the general heating system. Advantageously, the device 1 further comprises at least a bypass duct 25, as can be seen in Figures 5 and 7, connecting the second path 16 and the third path 19, which houses a bypass valve 26 allowing water to flow from the third to the second path 16 when water pressure in the device 1 is above a pre-established value. Such bypass duct 25 enables for instance to prevent the system and the pump from being damaged in case the circulation of water within the low-temperature circuit 3 should be prevented, for instance due to the temporary shutting of all regulating heads 13a for the various heating elements 13. As an alternative it can be provided for a stop of the pump 22 controlled by a global control system of the de- vice 1. The device 1 further comprises at least a safety thermostatic switch (not shown in the figures) operatively connected to said device 1 and in particular to the flow-regulating means 24 so as to stop the flow of high-temperature water in the first inlet 15a when the temperature within the third path 19 is above a pre- established threshold level, for instance 50 degrees centigrade. Such thermostatic switch is a further safety device against the damage of the low-temperature circuit 3 and of the structures in contact with the latter. The de- vice 1 is further provided with thermometers 27 placed in some water paths so as to indicate water temperature in the concerned path. The device 1 further comprises at least an adjustable closing element 28, for instance a holder or a ball valve, so as to block the flow of fluid in the device 1, and at least an outlet tap 8 so as to empty the device 1. In particular, stopping elements are provided on the first outlet 15b and on the third inlet 19a, so as to insulate the pump 22, and on the fourth outlet 20b. The device 1 further comprises at least some automatic relief valves 9 expelling air bubbles that might form in the system.

The heating system is further equipped with known means for controlling the working of said system, which comprise a system for regulating temperature in the room, either with manual or automatic control and controlling the intake of high-temperature water into the device 1 when room temperature detected in the room . is below a pre-established value.

The working of a regulating device for heating system according to the present invention, as described above mainly from a structural point of view, is the following. The adjustable holder 23 on the re-circulation opening 17 is adjusted while installing the device 1, so as to obtain the maximum potentiality of the low—temperature heating circuit 3. Accordingly, the thermostatic head 24a automatically regulates on the basis of the temperatures detected by the sensor 24c placed in the third path 19, the flow of high-temperature water, which is introduced into the device 1 and mixed with a given amount of low- temperature return water in the second path 16. Such mixed water then goes out of the first outlet 15b and is pushed by the pump 22 through the third path 19 of the second body 18, and then into the intake manifold 11 of the low-temperature circuit 3. The water coming back from the low-temperature circuit 3 gets into the second inlet 16a and is partly sent through the re-circulation opening 17 and partly gets out of the second outlet 16b and reaches the fourth path 20 of the second body 18, from where it is re-introduced into the high-temperature circuit 2 through the fourth outlet 20b. Obviously, since these are closed circuits, given a certain flow of high- temperature water entering the device 1, there is a corresponding flow of low-temperature water getting out of the second outlet 16b and then from the fourth outlet 20b. When the thermostatic head 24a wholly closes the first inlet 15a, all low-temperature water is recirculated in the low-temperature circuit 3. Reference values for water operating temperatures in the various parts of the device 1 can be for instance the following: in the first inlet 15a water is at about 70-80°C, in the first outlet 15b, after pre-mixing, at about 40-42°C, as in the third outlet 19b and therefore in the low- temperature intake manifold 11, whereas in the second inlet 16a and in the low-temperature return manifold 12 water is at about 30-32°C. Obviously, several changes and variants can be made to a device according to the present invention and to its components without leaving its characterizing inventive idea. It should be pointed out that all details can be replaced by other technically equivalent elements, and in practice all materials and sizes can be used according to needs.

The invention has important advantages. First of all, it should be pointed out that a regulating device for heating systems according to the invention has a highly si - ple and rational structure. Moreover, it should be pointed out that such. regulating device has a very small size and a global compact structure. Furthermore, the invention can be easily carried out and rapidly and easily installed. A device according to the invention is further reliable and efficient and ensures a high operating safety. Said device enables an optimal regulation of temperature both in single domestic systems and in central heating systems. Finally, it should be noted that a regu- lating device according to the present invention has extremely low manufacturing, installation and maintenance costs .

Claims

1. Regulating device for heating systems comprising: a first body (14) defining at least a first path (15) for a fluid, which extends at least from a first inlet (15a) to a first outlet (15b) , and a second path (16) for the fluid extending at least from a second inlet (16a) to a second outlet 16b; and a second body (18) defining at least a third path (19) for the fluid, which extends at least from a third inlet (19a) , operatively connected to said first outlet (15b) , to a third outlet (19b) , said first path (15) being operatively connected to said second path (16) by means of a re-circulation opening (17) so as to mix a pre- established amount of the fluid flowing in the second path (16) with the fluid flowing in the first path (16) .

2. Device according to claim 1, characterized in that said second outlet (16b) is placed between said second inlet (16a) and said re-circulation opening (17) .

3. Device according to claims 1 or 2 , characterized in that said first inlet (15a) and said second outlet (16b) are operatively connectable to a boiler or to a heating circuit (2) with high-temperature water, and in that said second inlet (16a) and said third outlet (19b) are operatively connectable to a heating circuit (3) with low- temperature water.

4. Device according to claim 3, characterized in that said second body (18) further defines a fourth path (20) for the fluid extending at least from a fourth inlet (20a) , operatively connected to said second outlet (16b) , to a fourth outlet (20b) operatively connectable to the boiler or to the heating circuit (2) with high- temperature water.

5. Device according to any of the preceding claims, characterized in that it further comprises a pump (22) for circulating fluid, which is operatively arranged between said first outlet (15b) and said third inlet (19a) .

6. Device according to any of the preceding claims, characterized in that it further comprises means (23) for varying the amount of fluid flowing from said second path (16) to said first path (15) , which are operatively associated to the first body (14) on said re-circulation opening (17) .

7. Device according to claim 6, characterized in that said varying means (23) comprise an adjustable holder.

8. Device according to any of the preceding claims, characterized in that said first body (14) and/or said second body (18) are carried out each as one piece.

9. Device according to any of the preceding claims, characterized in that said first body (14) and/or said second body (18) consist of several parts mounted together.

10. Device according to any of the preceding claims, characterized in that said first inlet (15a) and said second inlet (16a) are placed in opposed positions with respect to the first body (14) and are substantially lined up.

11. Device according to claim 10, characterized in that said first outlet (15b) has a longitudinal axis substantially perpendicular to the axes of said first inlet (15a) and said second inlet (16a) .

12. Device according to any of the claims 4 to 11, characterized in that said third outlet (19b) and said fourth outlet (20b) are placed in opposed positions with respect to the second body (18) and are substantially lined up.

13. Device according to claim 12, characterized in that said third inlet (19a) has a longitudinal axis substantially perpendicular to the axes of said third (19b) and said fourth outlet (20b) .

14. Device according to any of the preceding claims, characterized in that it further comprises means (24) for regulating the flow of fluid through said first inlet (15a) , which are associated to said first body (14) in said first path (15) .

15. Device according to claim 14, characterized in that said flow-regulating means (24) comprise a thermostatic head (24a) operatively active so as to actuate a shutter (24b) placed in the first path (15) so as to vary the flow of intake liquid, and a sensor (24c) placed in said third path (19) and operatively connected to said thermostatic head (24a) .

16. Device according to claim 14, characterized in that said flow-regulating means (24) comprise an electric motor operatively active so as to actuate a holder placed in the first path (15) so as to vary the flow of intake liquid .

17. Device according to claims 14, 15 or 16, characterized in that it comprises means for controlling the working of the device (1) operatively connected to said flow- regulating means (24) .

18. Device according to any of the preceding claims, characterized in that it further comprises at least a bypass duct (25) connecting said second path (16) and said third path (19) , and a bypass valve (26) placed in the bypass duct (25) so as to enable the flow of fluid from the third (19) to the second path (16) when the pressure of the fluid in the device (1) is above a pre-established value .

19. Device according to any of the preceding claims, characterized in that it further comprises at least a safety thermostatic switch operatively connected to the device (1) so as to block the flow of fluid in the first ■inlet (15a) when the temperature in the third path (19) is above a pre-established threshold value.

20. Device according to any of the preceding claims, characterized in that it further comprises at least a thermometer (27) placed in at least one of said fluid paths so as to indicate the temperature of the fluid in its respective path.

21. Device according to any of the preceding claims, characterized in that it further comprises at least an adjustable closing element (28) for blocking the flow of fluid in the device, and at least an outlet tap (8) for emptying the device (1) .

22. Device according to any of the preceding claims, characterized in that it further comprises at least an automatic air relief valve (9) .

23. Heating system for rooms characterized in that it comprises a device (1) according to any of the preceding claims .