WO1991000481A1

WO1991000481A1 - Heating boiler

Info

Publication number: WO1991000481A1
Application number: PCT/CH1990/000150
Authority: WO
Inventors: Jörg Füllemann; Heinrich Boner
Original assignee: Füllemann Patent Ag
Priority date: 1989-06-26
Filing date: 1990-06-22
Publication date: 1991-01-10
Also published as: EP0406173A2; EP0406173B1; PL164910B1; EP0406173A3; DD295904A5; CA2033988A1; CZ281126B6; PL285725A1; HU209911B; HUT58410A; ATE75024T1; CS306290A3; AU5832890A; DE59000086D1; HU904743D0

Abstract

A heating boiler comprises a heat-exchange chamber (13) surrounded by a heating jacket (15). Another water jacket (27) arranged concentrically with the latter extends, at the rear of the heating boiler, over approximately half the length of the heating jacket (15). A concentric core body (43) is located inside the water jacket (27). Helical flue gas channels (54, 56) each provided with an outlet (33, 37, respectively), are arranged in the spaces (53, 55, respectively. A flue gas flap (39) is located in the opening region of the outlets (33, 37). In the central position illustrated, the flue gases can escape virtually unhindered from both flue gas channels. This corresponds to full-load operation of the burner (11). At minimal load, the outlet (33) is closed by the flue gas flap. In both cases, however, the flue gas temperature is the same. This prevents the temperature in every part of the heating boiler from descending below the dew point.

Description

boiler

The invention relates to a boiler, in particular for use with a multi-stage or modulating burner, with a heat exchange valve, a water jacket surrounding it, which has an outer wall on an inner wall, and a further water jacket arranged in the heat exchange room, which extends over part extends the length of the heat exchange space and thus forms an intermediate space and encases an interior.

French patent specification 2,154,347 describes a boiler in which two cylindrical water jackets are arranged concentrically to one another. The inner space encased by the inner water jacket forms the burner chamber, while the space between the water jackets serves as a flue gas duct. There is a screw-shaped insert in this flue gas duct. The construction of this boiler is relatively complicated. The manufacture is therefore relatively expensive, and the service work is difficult to carry out and time-consuming. A particular disadvantage is the risk of cold spots, where, with reduced burner output, pollutants from the flue gases can condense, which then leads to corrosion problems. This boiler is therefore unsuitable for operation with a multi-stage burner. The prior art boiler also sees no means for hot water preparation, i.e. for so-called hot water preparation.

It is important that the boiler and burner output are coordinated. Until now, different boiler sizes were required in the lower power range in increments of around 5 KW.

It is therefore an object of the present invention to provide a structurally simple and inexpensive heating boiler with high thermal efficiency. The boiler should also be suitable for use with a multi-stage or modulating burner without the risk of corrosion consists. Furthermore, the boiler should have low standstill losses and, if possible, should also be suitable for treating hot water.

According to the invention, this object is achieved in a boiler of the type mentioned at the outset in that, in addition to the outlet leading from the intermediate space, an outlet leading from the interior for flue gases is provided and that means for regulating a flue gas flow from the outlet of the intermediate space and / or are provided for regulating a flue gas flow from the outlet of the interior. If the means for regulating the flue gas flows permit a flue gas flow both from the intermediate space and from the interior, the boiler can be operated at full load. The flue gases can then flow both through the space between the two water jackets and through the interior of the further water jacket and thereby transfer enough heat to these water jackets that they leave the boiler with a relatively low flue gas temperature. If, however, the boiler is only operated at partial load, which can be, for example, thirty percent of the full load, the outlet from the intermediate space is closed, so that the flue gases can only flow through the interior. There is then no risk that they will cool down too much and that condensation problems occur in the rear part of the boiler. The boiler is therefore well suited for use with a two-stage burner. However, it would also be possible to use a modulating burner which can be regulated continuously from minimum load to full load. In this case, it is expedient to choose a motor drive for the flue gas flap so that it can also be regulated continuously. It is therefore possible to regulate the size of the flue gas flow flowing through the space. The present invention also has the advantage that the same size of donkey can be used for a relatively large power range. When using the heating boiler with a single-stage burner, the same boiler size can be used for a relatively large output range. This means that there are considerably fewer different boiler sizes manufactured and kept in stock than was previously necessary. This enables a considerable reduction in production and storage costs. When installing a boiler with a single-stage burner, it is sufficient to manually set the means for regulating the flue gas flows in accordance with the burner output or the optimum exhaust gas temperature.

A flue gas flap is expediently provided as a means for regulating the flue gas flow. It can be provided that the. Outlets open into a common smoke pipe and that the flue gas flap is arranged so that when the outlet leading from the intermediate space is closed, it opens the outlet leading from the interior. For maximum burner output, the flue gas flap can thus be brought into a central position and the outlet from the intermediate space is closed for minimum burner output. In the middle position, the flue gas flap has practically no throttling effect for the two outlets. With a motor drive, however, it is also possible to bring the flue gas flap into a position in which it exerts a throttling effect on one of the outlets.

The water jacket surrounding the heat exchange space is advantageously a double jacket with an inner and an outer jacket space, which are separated from one another by a central wall. In this embodiment, the water in the inner jacket space is heated faster than the water in the outer jacket area when the boiler is started up. As a result, there is only a risk of condensate formation for a very short time during a cold start. Furthermore, the relatively cool return water flowing back during operation of the heating boiler cannot act on the inner wall. Rather, the water contained in the inner jacket space acts as a buffer against excessive cooling of the inner wall. This is particularly advantageous in low-temperature heating systems, where the return temperature is relatively low. As a result, there is no risk of the formation of undesirable condensates, which can result in corrosion. Another important advantage of the described One implementation is that standstill losses are greatly reduced. The water in the inner jacket space acts as insulation for the outer jacket room when the burner is at a standstill.

It has proven to be particularly advantageous to keep the distance between the inner wall and the central wall of the double jacket relatively small, preferably 5 to 15 mm. Thereby, temperature stratification of the water in the inner jacket space is avoided. So there is a good temperature distribution. Boiling noises are also avoided. The water content of the inner jacket space is relatively small. This has the advantage that, during operation, the water in the inner jacket space is rapidly heated, which on the one hand prevents corrosion problems and on the other hand can be used to charge a boiler quickly if necessary. This boiler can therefore be of relatively small dimensions because, when there is a large demand for hot water, it can give off hot water practically like a water heater.

Since the water content of the inner jacket space is small, the cooling of this water after the boiler has been charged means that relatively little heat is lost due to loss of standstill. The hot water is therefore also »processed in summer with a very high overall efficiency. This is in marked contrast to known boilers, whose overall efficiency is notoriously low in summer, so that electric heating is generally suggested for summer.

The distance between the middle wall and the outer wall of the double jacket is expediently substantially greater than the distance between the inner wall and the middle wall. This results in a sufficient volume for the boiler water required, for example, for space heating.

The boiler is advantageously designed such that the further water jacket is approximately half as long as the first-mentioned water jacket. This creates a combustion chamber with a large diameter on the burner side, which is especially suitable for modern ones Gasification burner with a rapidly expanding flame is suitable. Strongly expanding flames have a favorable flame temperature at which the formation of nitrogen oxides is very low.

The further water jacket is advantageously attached to the rear wall of the heat exchange space. This results in a simple construction of the boiler, in which the interior is easily accessible in order to carry out cleaning work.

A core body is advantageously arranged in the interior enclosed by the further water jacket, forming an intermediate space. This intermediate space allows the smoke gases to be guided to promote heat transfer. The various components of the boiler are advantageously designed to be cylindrical. This enables a rational and inexpensive manufacture of the boiler, in particular if the various elements are arranged coaxially with one another. The boiler can be implemented, for example, as a welded steel structure. The further water jacket and the core body can also be surrounded by an approximately helical flue gas duct. Such flue gas channels represent a relatively long way for the flue gases, so that an optimal heat exchange takes place. All heat exchange surfaces are smeared evenly by the flue gases. This also has the advantage that the risk of condensation from the flue gases is reduced even further. The flue gas ducts are expediently dimensioned such that the boiler works with an overpressure in the combustion chamber of about 0.5 As 6 mm mercury column, preferably 2 mm. This presupposes the use of means for generating the excess pressure, for example a fan burner. Such a combination works very quietly. The flue gas ducts can be formed by an insert from a helically wound sheet metal strip. This enables the flue gas ducts to be designed extremely cheaply. This version also has the advantage that the boiler can be cleaned using a screw insert can easily be pulled out.

The cross section of the flue gas ducts advantageously decreases from front to back. Because the flue gases cool down on the way back, their volume decreases so that the cross-section at the back can be made smaller than at the front. This reduction in cross-section has the advantage that the length of the flue gas duct can be made longer. It is particularly advantageous that the smoke gas duct provides strong noise reduction. The changing cross section prevents the formation of resonant vibrations. The progressive reduction of the cross section can be achieved, for example, by the fact that the pitch of the helically wound sheet metal strip decreases from the front to the rear. Since a helically wound sheet metal strip is relatively unstable, the turns of the sheet metal strip are expediently connected to one another with spacers. This allows the desired distance between two turns to be defined.

The core body is advantageously hollow. For example, openings can be provided in the jacket. The cavity in the core body dampens vibrations. In particular, the gas volume in the core body can absorb pressure differences which arise from the so-called start-up shock when the flame is ignited. The core body thus acts as a silencer. Particularly good sound damping properties are achieved if the cavity is loosely filled with mineral fibers, e.g. Rock wool, is filled. This filling also largely prevents undesired heat transfer.

The further water jacket is advantageously connected in series with the inner jacket space of the double jacket. This causes hot water to flow from the inner jacket space into the further water jacket, so that it is brought quickly over the dew point area, where no more condensation can take place. It is expedient between the further Water jacket and the inner jacket space arranged a pump. This ensures good circulation, which in turn causes a good temperature distribution. Since the volume of water is relatively small and can therefore be circulated quickly, the heat is dissipated quickly and boiling noises are avoided. A valve can also be provided in order to charge a boiler.

The flow and return of the heating circuit are expediently connected to the outer jacket space of the double jacket. It is advantageous if the flow is connected to one end of the double jacket and the return to the other end of the double jacket.

The invention also relates to a boiler with a heat exchange space and a water jacket surrounding it, which has an outer wall and an inner wall. According to the invention, this boiler is characterized in that the water jacket is a double jacket which has an inner and an outer jacket space, which are separated from one another by a central wall. This boiler represents a simplification of the boiler described above. It is essential that the same components can be used for the most part for both types of boiler. It proves to be advantageous to arrange a core body in the jacket space to form an intermediate space. This in turn brings the advantages of an inexpensive flue gas duct, wherein a helical flue gas duct can also be used, as was described above.

The invention will now be described with reference to the drawing. It shows:

Fig. 1 shows schematically a boiler and its use in a heating system with a two-stage or a modulating burner and

Fig. 2 shows a simplified version of the boiler, the Particularly suitable for a heating system with a single-stage burner.

The heating system of Fig. 1 shows a boiler 10 which consists of a multi-stage, e.g. two-stage, or a modulating burner 11 is fired. The heat exchange space 13 is surrounded by a water jacket 15. The water jacket 15 is designed as a double jacket with an inner jacket space 17 and an outer jacket space 19. The inner casing space 17 is separated from the outer casing space 19 by a central wall 21. The distance between the inner wall 23 and the middle wall 21 is relatively small, e.g. 10 to 15 mm. In a 25 KW boiler, the water volume in the inner jacket space is kept at about five liters. The distance between the middle wall 21 and the outer wall 25 is, depending on requirements, much greater than the distance between the inner wall 23 and the middle wall 21. Since the pollutant emissions are greatest at the start and when parking,

short fuel run times must be avoided. Accordingly, the water volume of the outer jacket space is to be measured. The relatively small water volume of the inner jacket space 17 can quickly be brought to operating temperature. A further cylindrical water jacket 27 is arranged concentrically with the preferably cylindrical double jacket 15. The inner jacket space 17 is connected in series with the water jacket 27 via a line 28 in order to avoid condensation and corrosion problems. The water jacket 27 is fastened to the rear wall 29 of the heat exchange space 13 and extends only over part of the length, for example half, of the heat exchange space 13. The front part 31 of the heat exchange space 13 therefore represents a combustion chamber with a relatively large size Diameter which is particularly suitable for modern gasification burners with a strongly expanding flame. The space between the double jacket 15 and the further water jacket 27 has a flue gas outlet 33 at the rear, which can be closed by a flue gas flap 39. The interior 35 surrounded by the further water jacket 27 has a flue gas outlet 37. The flue gas flap 39 is driven to drive the flue gas flap 39 Solenoid or a motor 41. When using the boiler with a single-stage burner, a drive is unnecessary. The flue gas damper is then manually brought into the position in which the exhaust gas temperature has the optimum value. A hollow cylindrical core body 43 is arranged concentrically with the further water jacket 27. This is closed at the front by a plate 45 made of refractory material. In the case of an atomizing burner, the plate 45 serves as a combustion aid. Any oil droplets that hit it can evaporate on the hot surface, whereupon the resulting gas burns practically without the formation of pollutants. The rear part is also advantageously closed off by a disk 47. In the coat

49 there is a large number of openings 51. In the cavity

50 there is a filling 52 made of rock wool or the like. Sound attenuation is thereby achieved and undesired heat transfer to the outlet 33 is largely prevented. A helical flue gas duct 54 or 56 is formed both in the intermediate space 53 and in the intermediate space 55. These flue gas channels 54, 56 consist of a helically wound sheet metal strip, which has the shape of an insert. The slope of the helically wound sheet metal strip decreases from the front to the rear, so that the cross section of the flue gas duct also decreases from the front to the rear. The turns of the sheet metal strip are with spacers, e.g. Rods (not drawn), connected together.

The use of the boiler 10 in a heating system can also be seen from FIG. The flow 59 leads from the front end of the outer casing space 19 to a mixing valve 61 and from there via the circulation pump 63 to the consumers 65. The return flow 67 is fed to the outer casing space 19 at the rear end of the boiler. A bypass 70 leads from the return 67 to the mixing valve 61.

A feed line 71 leads from the further water jacket 27 to the heat exchanger coil 73 of the boiler 75. The return line 77 from the heat exchanger coil 73 leads via the valve 79 and the pump 81 to the inner jacket space 17. A bypass 83 to the valve 79 is provided from the feed line 71.

The reference numeral 85 schematically shows a control device which controls the heating system.

The simplified embodiment of the boiler according to FIG. 2 differs from that of FIG. 1 in that a further water jacket and a further flue gas outlet with a flue gas flap are missing. For this purpose, the core body 43 has a larger diameter. This diameter corresponds to the diameter of the further water jacket 27 of FIG. 1. The boiler of FIG. 2 can therefore be built with practically the same parts as the boiler of FIG. 1, which has a favorable effect on the production costs and the spare parts inventory. Since the further water jacket 27 has been left out of FIG. 1, in the embodiment of FIG. 2 the flow line 71 leads from the inner jacket space 17 to the heat exchanger coil 73. Otherwise, the heating system is configured in the same way as in FIG. so that reference can be made to the relevant description.

Various changes are possible without deviating from the inventive concept. For example, a boiler construction with a vertical construction is also possible.

The following is also noted regarding the mode of operation of the heating system from FIG. 1:

When charging the boiler, the burner runs at full load. Relatively cool water is pumped into the inner jacket space 17 by the pump 81 and distributed fairly quickly and uniformly over the entire jacket space. Rapid preheating takes place, whereupon the water flows into the inner water jacket 27, is further heated there and flows back to the heat exchanger coil 73 of the boiler 75. In the boiler 75, heat exchange is used to heat the process water. When the controller 85 requests heat generation for space heating, the pump runs 81 even if the boiler 75 does not need to be charged. However, since the water heated in the inner water jacket flows through the bypass 83, it reaches the inner jacket room 17 without any noticeable heat loss. From there, the heat which originates from the inner jacket room 17 or is transferred from the heat exchange room 13 directly to the inner wall 23 , transferred via the middle wall 21 to the outer jacket space 19, in which there is circulation due to the operation of the circulation pump 63, which favors the heat exchange.

Claims

1. A boiler, in particular for use with a multi-stage or modulating burner, with a heat exchange space (13), a water jacket (15) surrounding it, which has an outer wall (25) and an inner wall (23), and one in the heat exchange space (13) arranged further water jacket (27), which extends over part of the length of the heat exchange space (13) and thus forms an intermediate space (53) and encases an inner space, and one from the intermediate space (53) leading outlet (33) for flue gases, characterized in that in addition to the outlet leading from the intermediate space, an outlet (37) leading from the interior for smoke gases is provided and that means for regulating a flue gas flow from the outlet of the intermediate space and / or are provided to regulate a flue gas flow from the outlet of the interior.

2. Boiler according to claim 1, characterized in that a flue gas flap is provided as means for regulating the flue gas flow.

3. Boiler according to claim 2, characterized in that the outlets open into a common smoke pipe and that the flue gas flap is arranged so that when the outlet leading from the intermediate space is closed, it opens the outlet leading from the interior.

4. Boiler according to one of claims 1 to 4, characterized ge indicates that a motor drive for the Rauchgasklap¬ pe is provided.

5. Boiler according to one of claims 1 to 4, characterized ge indicates that the heat exchange space (13) surrounding water jacket (15) is a double jacket with an inner and an outer jacket space (17, 19) through a central wall (21 ) are separated from each other.

6. A boiler according to claim 5, characterized in that the distance between the inner wall (23) and the central wall (21) of the double jacket (15) is relatively small, preferably 5 to 15 mm.

7. Boiler according to claim 6, characterized in that the distance between the central wall (21) and the outer wall (25) of the double jacket (15) is substantially larger than the distance between the inner wall (23) and the central wall ( 21).

8. Boiler according to one of claims 1 to 7, characterized ge indicates that the further water jacket (27) is about half as long as the first-mentioned water jacket (15).

9. Boiler according to one of claims 1 to 8, characterized ge indicates that the further water jacket (27) on the rear wall of the Wärmetauschraumε (13) is attached.

10. Boiler according to one of claims 1 to 9, characterized ge indicates that in the interior of the further water jacket (27) enclosed (50) a core body (43) is arranged to form an intermediate space (53).

11. Boiler according to one of claims 1 to 10, characterized ge indicates that the heat exchange space (13) is cylindrical.

12. Boiler according to one of claims 1 to 11, characterized ge indicates that the further water jacket (27) is cylindrical.

13. Boiler according to one of claims 1 to 12, characterized ge indicates that the core body (43) is cylindrical.

14. Boiler according to one of claims 1 to 13, characterized ge indicates that the further water jacket (27) is arranged coaxially in the heat exchange space (13).

15. Boiler according to one of claims 1 to 14, characterized ge indicates that the core body (43) is arranged coaxially in the further water jacket (27).

16. Boiler according to one of claims 1 to 15, characterized ge indicates that the further water jacket (27) is surrounded by an approximately helical flue gas duct (54).

17. Boiler according to one of claims 1 to 16, characterized ge indicates that the core body (43) is surrounded by an approximately helical flue gas duct (56).

18. Boiler according to claim 16 or 17, characterized gekennzeich¬ net that the respective helical flue gas channel (54, 56) is formed by an insert from a helically wound sheet metal strip.

19. Boiler according to one of claims 16 to 18, characterized in that the cross section of the respective Rauch¬ gas channel (54, 56) decreases from front to back.

20. Boiler according to one of claims 16 to 19, characterized in that the slope of the helically wound sheet metal strip decreases from the front to the rear.

21. Boiler according to one of claims 18 to 20, characterized in that the turns of the sheet metal strip are connected to one another with spacers.

22. Boiler according to one of claims 10 to 21, characterized in that the core body (43) has a cavity (50).

23. A boiler according to claim 22, characterized in that the core body (43) has openings (51).

24. A boiler according to claim 22 or 23, characterized net that the cavity (50) is filled with mineral fibers, such as rock wool (52).

25. Boiler according to one of claims 5 to 24, characterized in that the further water jacket (27) with the inner jacket space (17) of the double jacket (15) is connected in series.

26. A boiler according to one of claims 1 to 25, characterized in that a pump (81) is arranged between the further water jacket (27) and the inner jacket space (17).

27. A boiler according to claim 26 with a boiler, characterized in that a valve (79) for charging a boiler (75) with the pump (81) is provided.

28. Boiler according to one of claims 25 to 27, characterized in that the flow (59) and the return (67) of the heating circuit (65) to the outer jacket space (19) of the double jacket (15) are connected.

29. A boiler according to claim 28, characterized in that the flow (59) is connected at the bottom at one end of the double jacket (15) and the return (67) is connected at the top at the other end of the double jacket (15).

30. A boiler with a heat exchange space (13) and a water jacket (15) surrounding it, which has an outer wall (25) and an inner wall (23), characterized in that the water jacket (15) is a double jacket that has an inner and an outer jacket space (17, 19) which are separated from one another by a central wall (21).

31. A boiler according to claim 30, characterized in that a core body (43) is arranged in the heat exchange space to form an intermediate space (54, 13).

32. A boiler according to claim 31, characterized in that the distance between the inner wall and the central wall of the double jacket is relatively small, preferably

5 to 15 mm.

33. A boiler according to claim 32, characterized in that the distance between the central wall (21) and the outer wall (25) is substantially larger, preferably three to ten times, than the distance between the inner wall (23) and the central wall ( 21).

34. Boiler according to one of claims 31 to 33, characterized in that the core body (43) is approximately half as long as the water jacket (15).

35. Boiler according to one of claims 31 to 34, characterized in that the core body (43) is cylindrical.

36. A boiler according to claim 35, characterized in that the core body (43) is arranged coaxially in the water jacket (15).

37. A boiler according to claim 36, characterized in that the core body (43) is surrounded by an approximately helical flue gas duct (54).

38. A boiler according to claim 37, characterized in that the helical flue gas duct (54) is formed by an insert from a helically wound sheet metal strip.

39. Boiler according to one of claims 37 to 38, characterized in that the cross section of the flue gas duct (54) decreases from front to back.

40. A boiler according to claim 38 or 39, characterized gekennzeich¬ net that the slope of the helically wound sheet metal strip decreases from front to back.

41. Boiler according to one of claims 38 to 40, characterized in that the turns of the sheet metal strip are connected to one another with spacers.

42. Boiler according to one of claims 31 to 41, characterized in that the core body (43) has a cavity (50).

43. A boiler according to claim 42, characterized in that the core body (43) has openings (51) in its jacket.

44. Boiler according to claim 42 or 43, characterized gekennzeich¬ net that the cavity (50) with mineral fibers, e.g. Rock wool (52), is filled.

45. Boiler according to one of claims 30 to 44 with a boiler (75), characterized in that a section of the inner jacket space (17) is connected to another section of the inner jacket space (17) via a pump (81).

46. A boiler according to claim 45, characterized in that the lower section of the inner casing space (17) is connected to the upper section of the inner casing space (17) via the pump (81).

47. A boiler according to claim 46 with a boiler, characterized in that a valve (79) for charging the boiler (75) with the pump (81) is provided.

48. Boiler according to one of claims 45 to 47, characterized in that the flow (59) and the return (67) of the heating circuit (65) are connected to the outer jacket space (19) of the double jacket (15).

49. Boiler according to claim 48, characterized in that the flow (59) at one end of the double jacket (15) below and the return (67) at the other end of the double jacket (15) are connected above.