ES2541777T3 - Installation and procedure of hot water production - Google Patents

Abstract

Hot water production installation comprising an outer casing (1), an upper closing plate (2), a lower closing plate (3), a burner (4) with injection device (5) and combustion chamber ( 6) comprising smoke pipes (7) arranged in the envelope (1), as well as at least one tank / exchanger or an exchanger disposed inside the envelope (1), the interior space of the envelope consisting of a separation partition (11) that creates in the envelope (1) an upper part (12) and a lower part (13), characterized in that the upper and lower parts (12, 13) are a lower chamber (13) and a upper chamber (12) superimposed, of which the upper chamber (12) is permanently maintained at elevated temperature, because the smoke pipes pass through said upper and lower chambers (12, 13) and the partition wall (11), by that the partition wall (11) consists of a communication device (23) between the upper and lower chambers (12, 13), and because the burner (4) is placed on the upper closing plate (2), so that the course of the fumes is done vertically from top to bottom by means of the pipes of fumes (7) that pass through the two chambers (12, 13) that constitute the two primary circuits of the installation, working the upper chamber (12) at high temperature, while the lower chamber (13) is used at low temperature in the smoke condensation zone.

Description

E04447139

07-07-2015

DESCRIPTION

Installation and procedure of hot water production

5 The object of the present invention is a hot water production installation comprising an outer casing, an upper closing plate, a lower closing plate, a burner with injection device and combustion chamber comprising smoke pipes arranged in the envelope, as well as at least one reservoir / exchanger or an exchanger disposed inside the envelope, the interior space of the envelope consisting of an upper part and a lower part. It refers more particularly to a condensation installation that can be used for central heating and / or the production of hot water for domestic, tertiary, industrial or other use.

Among the usual boilers without condensation, it refers to a first type of boilers in which the steel exchanger tank, which contains the sanitary water, is submerged in the primary circuit with the water of

15 heating. This type of boiler provides multiple advantages:

- Sanitary water is stored at high temperature (> 60 ºC) which increases comfort and avoids any risk of bacterial development, such as legionella;

-the partitions of the sanitary tank are not in direct contact with the hottest parts of the boiler thanks to the presence of the primary circuit; this prevents the formation of limestone in the hottest points, as well as a deterioration of the boiler's performance over time;

-the sanitary deposit is free to deform during pressure variations, which prevents the limestone from being fixed on the walls of the exchanger; -the volume of stored water is reduced and allows only to respond to a peak demand; consequently, losses per stop are very scarce; -the heat exchanger heating surface is important and the system works like an exchanger

Direct in case of high extraction, the recovery time after extraction is very short; -corrosion resistance through the use of stainless steel; -No protection anode and maintenance free.

However, the market demands boilers with an increasingly high yield. This increase in yields translates into the use of condensing boilers in which latent heat contained in the fumes from combustion is recovered. The dew point temperature is around 55 ° C and condensation is therefore impossible in a boiler permanently maintained at a temperature of at

35 minus 60 ° C.

Condensing boilers have been developed to recover a maximum of energy from combustion gases. In fact, when the temperature of the flue gases falls below about 50 ° C, condensation droplets form on the heat exchanger elements and fall by gravity towards the lower part of the boiler. This condensation liquid is very corrosive and, therefore, avoids placing the burner under the boiler due to its rapid deterioration.

Several solutions have been proposed:

A condensation exchanger is provided at the top of the boiler, as described in patent document FR 2 821 924. In this case, this condensation zone is completely separated from the combustion zone by an inclined bottom which guarantees the recovery and evacuation of condensates; -the burner is arranged in the center of the boiler and a condensation zone is provided below the burner, as described and illustrated in GB 2 140 138; -the burner is placed in an inverted position above the boiler, as described in documents DE 33 29 777 or DE 36 25 479. In this way, condensates can be easily recovered, by gravity, at the bottom of the boiler

55 It should be noted, however, that these last two documents do not refer to condensing boilers, but already illustrate the arrangement of the inverted burner.

Experience has shown that a device made according to the submerged tank technique (called “annular tank in tank”), commonly used by the applicant, gives very good results from the point of view of exchange and thermal performance, as already He explained above.

This technique consists in submerging an annular cylindrical tank, which contains the domestic hot water, in a second outer tank that forms the primary circuit. The flue pipes exchange their heat in the primary circuit, which, in turn, exchanges, at a lower temperature, its heat in the domestic hot water by means of

65 tank / exchanger walls. The primary circuit, depending on the case, is used either for a heating circuit, or is closed for strict production of hot water.

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From US-A-4426037, a heating installation is known to produce heating hot water and domestic hot water. The installation consists of an outer casing, an upper closing plate, a lower closing plate, a burner with a combustion chamber, and pipes for the passage of fumes from the combustion chamber, said tubes serving as a heat exchanger. The envelope also consists of a

5 coil through which domestic water runs to reheat it, as well as connections to connect it to a central heating circuit.

The combustion chamber divides the envelope into a lower part located below the combustion chamber, a lower part in which the pipes for the passage of fumes extend, and in an upper part located above the combustion chamber that it forms a reservoir in which no pipe for the passage of smoke extends. The upper part or low volume tank is not heated by the passage of smoke.

The objective of the present invention is to combine the advantages related to the technique called "tank in tank" with the technique of condensing boilers, in order to obtain a thermal installation capable of

15 provide central heating water, as well as sanitary water in any condition and with a performance close to the theoretical maximum performance.

With a view to achieving this objective, the installation object of the present invention is distinguished by the fact that it has the characteristics as specified in the claims appended hereto.

Therefore, the object of the invention is a hot water production installation comprising an outer casing (1), an upper closing plate (2), a lower closing plate (3), a burner (4) with device of injection (5) and combustion chamber (6) comprising smoke tubes (7) arranged in the casing (1), as well as at least one tank / exchanger or an exchanger arranged inside the casing (1 ), the interior space of the envelope consisting of a partition wall (11) that creates in the envelope

(1) an upper part (12) and a lower part (13), characterized in that the upper and lower parts (12, 13) are a lower chamber (13) and an upper chamber (12) superimposed, of which the upper chamber (12) is permanently maintained at elevated temperature, because the smoke pipes pass through said upper and lower chambers (12, 13) and the separation wall (11), because the separation wall (11) consists of a communication device (23) between the upper and lower chambers (12, 13), and because the burner (4) is placed on the upper closing plate (2), so that the course of the fumes is done vertically from top down by means of the smoke pipes (7) that cross the two chambers (12, 13) that constitute the two primary circuits of the installation, working the upper chamber (12) at high

35 temperature, while the lower chamber (13) is used at low temperature in the smoke condensation zone.

In order to make the invention well understood, an example of practical embodiment will be described below, with the help of the attached drawing which represents a vertical sectional view of a boiler according to the invention.

The figure shows a scheme of principle of a boiler device according to the invention.

The boiler comprises an outer envelope 1, generally cylindrical, comprising an upper closure plate 45 and a lower closure plate 3.

In the illustrated example, it is seen that a burner 4 is mounted against the upper plate 2 from which the injection device 5 extends downward on the axis of a combustion chamber 6.

The lower part of this combustion chamber 6 is connected to a series of flue pipes 7 that extend down to the lower closing plate 3. These pipes 7 are configured as heat exchangers, so that they absorb and distribute the maximum heat that comes from combustion gases.

A chamber 8 is mounted below the bottom plate 3 to recover combustion fumes and

55 condensates that are formed on the inner wall of the tubes 7. To this end, the chamber 8 is provided with a flue pipe 9 and a device 10 for recovering and evacuating the condensates.

According to the invention, the boiler, illustrated in the drawing, is constructed in two parts, separated in height by a partition 11, so that an upper chamber 12 and a lower chamber 13 are created; These cameras have different operating temperatures. The upper chamber 12 works at a high temperature and has a large volume of water, the lower chamber 13 is used at a low temperature in the condensation zone.

The burnt gas pipes 7 pass through the two chambers 12, 13 and the separation wall 11. The chambers 12 and

65 13 constitute the primary circuits of the installation containing the water used for central heating. This primary circuit is composed as follows:

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-the return 16 of the heating pipe is connected to the lower chamber 13; - an outlet 17 of this lower chamber 13 is connected through a pipeline 18 to a three-way valve 19;

5 -this valve 19 regulates the temperature of the heating outlet water; for this, it acts on the water flow through the upper chamber 12; the heating outlet pipe 20 is connected via a conduit 21 to an outlet 22 of the upper chamber 12;

-a direct passage of primary water, between chambers 13 and 12, is obtained thanks to a communication device 23 of the two primary circuits; This device, such as a calibrated hole, is provided in the partition 11.

- If necessary, a primary circulation loop can be provided in chamber 12 by means of a pipe (not illustrated) that forwards water, possibly through a circulation pump, from the upper part of chamber 12 towards the bottom of this chamber 12;

15 The return water of the heating system usually enters at a temperature of approximately 30 ° C through the inlet 16 of the lower chamber 13 and overheats a few degrees before leaving, either through the outlet 17 towards the valve 19, either by the device 23 of the partition 11 to the upper chamber 12. In this upper chamber 12 the water is heated between 60 and 90 ° C before leaving through the valve 19, where it is mixed with the water at approximately 32 ° C of the channel 18 for the heating outlet that needs approximately 50 ° C. It is understood, therefore, that the water in the upper chamber 12 will be constantly maintained at temperatures between 60 ° and 80 ° C, while the temperature of the lower chamber 13 will be maintained in a range a few degrees above the temperature of heating return.

Also according to the invention, in each of these chambers 12, 13 a tank / exchanger or a

25 internal exchanger, completely submerged in their respective chambers. In this way, an annular and coaxial reservoir / exchanger 14 is disposed in the upper chamber 12 with respect to the smoke pipe assembly 7 and the outer cylindrical shell 1.

In the lower chamber 13 there is a tank / exchanger or an exchanger 15 of smaller dimensions with respect to the tank 14. This tank / exchanger 15 is also annular and coaxial with respect to the whole of the smoke pipes 7 and the outer cylindrical shell one.

The water contained in these tanks / exchangers 14, 15 is intended for the use of domestic hot water. The circuit of this water is carried out in the following manner: 35 - the cold water inlet is made through the pipeline 24 that carries this water to the tank / exchanger 15 of the lower chamber 13;

-this cold water is reheated by the exchange of heat with the flue gases through the primary water circuit before leaving the tank / exchanger 15 through a duct 25 that conducts the water to the tank / exchanger 14 of the upper chamber 12;

-through the contact of this tank / exchanger 14 with the primary water of the chamber 12, the domestic water is reheated to a temperature higher than 60 ° C before leaving via the sanitary hot water supply pipe 26.

The temperature of the upper chamber 12 is maintained at a homogeneous temperature, possibly thanks to a primary circulation loop. In heating operation, different water flows irrigate the two chambers 12, 13 thanks to the action of the three-way valve 19; the flow rate is maximum in the lower part to favor condensation and limit the temperature increase. The flow rate in the upper chamber 12 is defined by the position of the three-way valve 19.

The smoke circuit only comprises a single passage through the tubes 7, which simplifies the construction and reduces the necessary space.

The upper part with the chamber 12 is maintained at a homogeneous temperature higher than 60 ° C by means of a regulating device that acts on the three-way valve 19.

The volume of the lower chamber 13 (low temperature) is limited, which allows reducing inertia during the transition from a high temperature mode of operation to a low temperature mode of operation.

In order to demonstrate the real advantages in practical operation, some tests have resulted in the following findings:

a) High temperature heating operation:

65 -The temperature of the return water is 60 ºC. -The temperature of the outlet water is 80 ºC.

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-The temperature increase in the lower part is scarce.

-The temperature of the primary water in the upper chamber is homogeneous and equal to or greater than 60 ºC (therefore, domestic hot water is available at any time). Test result:

5 Nominal load (Qn) = 39 kW Water yield (above pci) = 99.0% (pci = lower calorific value) Temp. chamber mean 12: 77 ° C.

b) Low temperature heating operation:

-The return water temperature is 30 ºC. -The outlet water temperature is 50 ° C. -The temperature increase in the lower chamber 13 is low. -The water temperature in the upper chamber 12 is homogeneous and equal to the desired water temperature

15 sanitary hot (over 60 ºC). -The outlet temperature of 50 ° C is achieved thanks to the mixing in the three-way valve 19 of a part of the water that comes from the lower chamber 13 and a part of the water that comes from the upper chamber

12.

Test results: Nominal load (Qn) = 39 kW Water yield (above pci) = 107.5% Temp. chamber average 12: 85 ºC 30% load, T return = 30 ºC (directive 92/42 / EEC) Water performance (above pci) = 108.6%

25 Temp. chamber mean 12: 72 ° C.

c) Mode operation: domestic hot water only:

-The temperature of the cold water is 10 ºC. -The temperature increase in the lower chamber 13 is low. - The sanitary water passes from the lower exchanger tank 15 to the upper exchanger tank 14

which is maintained at the desired temperature of domestic hot water.

Test results: Nominal load (Qn) = 39.0 kW

35 Continuous flow, ΔT = 30 K Water yield (over pci) = 105.9% Nominal load (Qn) = 39.0 kW Continuous flow, ΔT = 50 K Water performance (over pci) = 105%

It follows that the hot water production facility according to the invention comes to solve the problems raised and propose a multi-purpose boiler, which combines the following advantages: condensation in heating mode and in domestic hot water mode, storage of sanitary water at high temperature (> 60 ºC) integrated, high production of domestic hot water.

45 The condensation regime is achieved both in heating mode and in sanitary mode, but also in mixed operation (sanitary + heating).

Consequently, heating operation at a very low temperature becomes possible, while maintaining the storage of domestic hot water at a very high temperature.

Therefore, the boiler according to the invention comprises two primary circuits that are used at different temperatures. The upper part operates at high temperature and comprises a tank / exchanger for the production of domestic hot water.

55 The burner is placed in the upper part of the boiler and the fumes run vertically from top to bottom in an exchanger that crosses the two primary circuits.

Water flows in each of the primary circuits are regulated according to the desired outlet temperature.

Legends:

1 outer cylindrical shell 65 2 upper closure plate 3 lower closure plate

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4

burner

5

burner injection device

6

combustion chamber

7

smoke pipes

5

8 smoke chamber

9

flue outlet pipe

10

condensate drain line

eleven

partition wall

12

upper chamber

10

13 lower chamber

14

upper tank / exchanger

fifteen

lower tank / exchanger

16

heating input / return

17

lower chamber output

fifteen

18 output pipe

19

Valve of three paths

twenty

heating outlet pipe

twenty-one

conduit

22

upper chamber output

twenty

2. 3 primary circuit communication device

24

sanitary cold water inlet

25

sanitary water pipe

26

domestic hot water outlet

Claims (14)

1. Hot water production installation comprising an outer casing (1), an upper closing plate (2), a lower closing plate (3), a burner (4) with injection device (5) and a chamber 5 combustion (6) comprising smoke pipes (7) arranged in the casing (1), as well as at least one tank / exchanger or an exchanger disposed inside the casing (1), the interior space of the envelope of a partition wall (11) that creates in the envelope (1) an upper part (12) and a lower part (13), characterized in that the upper and lower parts (12, 13) are a lower chamber (13 ) and a superimposed upper chamber (12), of which the upper chamber (12) is permanently maintained at elevated temperature, because the flue pipes pass through said upper and lower chambers (12, 13) and the partition wall (11 ), because the partition wall (11) consists of a communication device (23) between the upper and lower chambers (12, 13), and why the burner (4) is placed on the upper closing plate (2 ), so that the course of the fumes 15 is done vertically from top to bottom by means of the smoke pipes (7) that cross the two chambers (12, 13) that constitute the two primary circuits of the installation, working the upper chamber (12) at high temperature, while the Lower chamber (13) is used at low temperature in the smoke condensation zone.

2.

Installation according to claim 1 for water heating of a primary circuit, characterized in that the lower chamber (13) and the upper chamber (12) each have an outlet (17, 22) for the primary circuit.

3.

Installation according to any one of the preceding claims, characterized in that the chamber

lower (13) contains a tank / exchanger or a lower heat exchanger (15) and because the upper chamber (12), of high temperature, contains a tank / upper heat exchanger (14).

Four.

Installation according to claim 3, characterized in that the tank / exchanger or the lower exchanger (15) and the tank / upper exchanger (14) are joined together by a pipe (25).

5.

Installation according to claim 4, characterized in that the lower tank / exchanger (15) has an inlet (24) for carrying domestic cold water and the upper tank / exchanger (14) has an outlet (26) for evacuating domestic hot water .

6.

Installation according to any one of the preceding claims, characterized in that the tube (s) of

35 fumes (7) join the combustion chamber (6) and extend to the lower closing plate (3), crossing the separation wall (11).

7.

Installation according to any one of the preceding claims, characterized in that the lower chamber (13) consists of a return input (16) of the primary circuit.

8.

Installation according to any one of the preceding claims, characterized in that it comprises a three-way valve (19) connected by a pipe to the lower chamber (13) and by a pipe (21) to the upper chamber (12).

Installation according to any one of the preceding claims, characterized in that the separation partition (11) consists of a passage device (26) of an appropriate water flow of the primary circuit of the lower chamber (13) to that of the upper chamber (12). 10. Installation according to any one of the preceding claims, characterized in that the upper chamber (12) is provided with a circulation loop that joins an outlet in the upper part of this chamber to an input in the lower part of this chamber (12). 11. Installation according to any one of the preceding claims, characterized in that the closing plate bottom (3) is provided on its bottom side of a smoke chamber (8) into which the smoke pipes 55 (7) flow.

12.

Installation according to claim 11, characterized in that the smoke chamber (8) is provided with a flue outlet pipe (9) and a condensate recovery and evacuation pipe (10).

13.

Production process for heating hot water for a primary circuit and / or for domestic hot water by means of an installation according to any one of the preceding claims.

14.

Method according to claim 13, characterized in that the temperature of the water in the upper chamber

(12) is heated between 60 ° C and 90 ° C. 65 15. Method according to claim 13 by means of an installation according to claim 2 for the 7 water heating of a primary circuit, characterized in that the return water of the primary circuit is returned to the lower chamber (13) to overheat in it, and that the two chambers (12, 13) are irrigated with water flows different. 8