DE212017000127U1 - Thermally conductive heater with integrated automatic water mixture to protect against low temperature corrosion - Google Patents

Abstract

A heat-conducting heater with integrated automatic water mixture for protection against low-temperature corrosion, comprising a water inlet (15) opening in the distributor (18), wherein the distributor (18) comprises at least one mixing opening (14), which opens into the water space (2) of the heater, characterized in that the water space (2) of the heater between the water inlet (15) and the water outlet (10) is reduced to at least one flow opening (16) with a water flow regulator (17).

Description

The invention relates to heat-conducting heaters with integrated automatic water mixture for protection against low-temperature corrosion, wherein the heat-transmitting water is automatically mixed inside the heater, so that the temperature of the heat exchange surfaces is higher than the dew point temperature of the exhaust gases, which ensures protection against low temperature corrosion. The invention relates in particular to heat-conducting solid fuel heaters which are connected to a container (accumulation tank).

When operating heat-conducting heaters, especially in boilers or furnaces with heat exchangers, during operation, an undesirable effect occurs - a low-temperature corrosion of the heat exchange surfaces. It is a chemical reaction in which the wall material of the heater reacts with oxygen, making the walls of the heater thinner and thinner. The corrosion of the heat exchange surfaces de facto determines the life of the heater. The ability to withstand low temperature corrosion is therefore the most important feature of the heater.

Exhaust gases that are produced during the combustion of conventional fuels (wood, coal, oil, gas, etc.) contain water vapor. When the water vapor condenses on the heat exchange surfaces of the heater, the corrosion intensity is many times higher.

The water vapor condenses when the temperature of the heat exchange surfaces is lower than the dew point temperature of the exhaust gases. The value of the dew point temperature of the exhaust gases is 40 to 60 ° C depending on the type of fuel. In order to avoid the condensation of steam on the heat exchange surfaces and thus the low temperature corrosion, the heat conducting heaters or the connection of these heaters contain various measures and ways that ensure that the temperature of the heat exchange surfaces is higher than the dew point temperature of the exhaust gases.

Among the known solutions is the connection of a heater with forced short circuit with a water temperature control. This solution is used in most of today's solid fuel heaters. This solution is based on the fact that the output and input line of the heater is connected to a short-circuit line. Through this line, a part of the output water is discharged and mixed with the input water. The water flow in the short-circuit line is ensured by a pump. The amount of water in the short-circuit line is usually controlled by an automatic 3-way mixing valve, so that the temperature of the inlet water is higher than the dew point temperature of the exhaust gases. The most commonly used automatic mixing valve uses a paraffin thermostat, the base of which is a paraffin container and a piston. Upon reaching the desired temperature, for. B. 60 ° C, melts the paraffin, increases its volume and expresses the piston. The piston is connected to a flap, which regulates the amount of water flowing through. The return movement is provided by a spring.

A disadvantage of the solution described is the necessity of installing a short-circuit line, a pump and a mixing valve, which involves investment and operating costs, requires a complicated installation and increases the risk of disturbances. Another disadvantage is the space required and heat losses through the surface of the installed device.

Other disadvantages are with heaters that are connected to a container (accumulation tank). In the event of a power failure, the automatic mixing valve closes the water supply to the heater, thus preventing the remaining power of the heater from being diverted into the tank by gravity circulation. To avoid overheating the heater, another device must be installed. This is z. B. a bypass line of the mixing valve with electronically controlled valve or a cooling loop in the heater, connected via a special thermostatic valve to an independent source of pressurized water or a spare power supply for the pump drive. The need for additional equipment increases the initial cost, complicates the installation and increases the risk of disruption.

Also known is the solution with an optimized supply of the input water. The basis of this solution is that the water supply to the heater is not directed into the bottom part, but for example in the middle or in the upper part. The input water is thus mixed with the water in the heater, which is already heated, so that the heat exchange surfaces do not come into contact with the cold input water. Many heaters still have channels of the rails in their water rooms, so that the most exposed surfaces come in contact with the already preheated water. Some variants of the mentioned solution use 10 to 20% of the current heaters. The disadvantage of this solution is that it is not always able to ensure a sufficient water temperature in the heater and thus does not ensure adequate protection against low temperature corrosion. About that In addition, this solution more or less restricts the function of gravity circulation, especially when connected to an accumulation tank at a height level with the heater. This solution is therefore used only as a supporting solution and combined with other measures.

Another known solution is the solution with optimized inlet water distribution, for example according to EP 0693 661 , In this solution, the inlet water opens in a manifold containing one or more mixing ports, the mixing ports open into the water chamber of the heater. The water flowing through these openings is mixed with the water in the water space of the boiler. The cooling of the heat exchange surfaces is thus minimized. The disadvantage of this solution is that the degree of protection does not work at every flow and at every water temperature. It is suitable in combination with other measures for gas or oil heating systems. In solid fuel boilers, this solution is inadequate and is not known to be used.

Another known solution is the temperature increase of the input water by external measures. The essence of this measure is that the heater is not connected with short circuit and mixer, but a measure is applied, which ensures that the temperature does not fall below the dew point temperature of the exhaust gases. For example, the circulation pump with thermostat does not switch until the water temperature at the outlet reaches 60 ° C or when the radiators are dimensioned and the capacity is maintained so that the temperature of the return water during operation is above 40 to 50 ° C. The common disadvantage of these solutions is that they do not ensure a sufficient temperature of the heat exchange surfaces in all operating conditions and not for all surfaces of the heaters. The protection against low temperature corrosion is therefore only possible with these solutions.

Another known solution is the use of a heater with multilayer heat exchange surfaces. The basis of this solution is that the water-cooled heat exchange surfaces are protected by another wall, usually made of sheet steel, and are not in direct contact with the exhaust gases. The additional wall is heated by the exhaust gases or the flame to a much higher temperature than the dew point temperature of the exhaust gases. Another wall transmits the heat predominantly by radiation into the water-cooled walls. The area between the walls is usually filled with combustion air. Multilayer heat exchange surfaces are used by most carburettor boilers to protect the filling chamber (so-called warm chamber system). It is not used for other heat exchange surfaces because its ability to cool flue gases is significantly reduced. Therefore, no complete protection is guaranteed, which is the main disadvantage of this solution.

• - dass sie bei jeder Temperatur und bei jedem Rückflusswasser funktioniert,
• - dass sie die Schwerkraftzirkulation des Wassers mit platziertem Behälter auf einem Höhenniveau mit dem Heizgerät ermöglicht,
• - dass sie keine Stromzuleitung benötigt,
• - dass sie keine Installation von Kurzschlusskreislauf mit Mischventil usw. erfordert und
• - dass sie einfach, kostengünstig und zuverlässig ist.

Each of the known solutions has its advantages and disadvantages. However, no solution is known that meets all of the following requirements:

• - that it works at any temperature and at any reflux water,
• that it allows the gravity circulation of the water with the container placed at a height level with the heater,
• - that it does not require power supply,
• - that it does not require installation of short circuit with mixing valve, etc. and
• - that it is simple, inexpensive and reliable.

It is an object of the invention to eliminate the disadvantages of the solutions described above.

The stated object is solved by the features of claim 1.

The basis of the invention is based on the water space of the heater is reduced based on the water temperature between the water inlet and the water outlet at least to a flow opening with a water flow regulator.

According to the first preferred embodiment of the invention, the water space of the heater comprises a partition having at least one flow opening with water flow regulator based on the water temperature.

It is advantageous if the water flow regulator consists of a container with paraffin, in which there is a piston which is connected to a flap, wherein the container is arranged with paraffin in the water space of the heater.

• - funktioniert bei jeder Temperatur und bei jedem Rückflusswasser,
• - ermöglicht Schwerkraftzirkulation des Wassers mit platziertem Behälter auf einem Höhenniveau mit dem Heizgerät,
• - erfordert keine Stromzuleitung,
• - erfordert keine Installation von Kurzschlusskreislauf mit Mischventil usw. und
• - die Lösung ist einfach, kostengünstig und zuverlässig.

An advantage of the heater according to the invention is that the heat transfer surfaces that are in contact with exhaust gases have a higher temperature than the dew point temperature of the exhaust gases, which prevents low temperature corrosion. At the same time it has the following advantages:

• - works at any temperature and at any reflux water,
• - allows gravity circulation of the water with the container placed at a height level with the heater,
• - requires no power supply,
• - requires no installation of short circuit with mixing valve, etc. and
• - The solution is simple, inexpensive and reliable.

• 1 eine Seitenansicht im Schnitt des Heizgeräts mit Trennwand im Wasserraum und Wasserflussregler in dieser Trennwand,
• 2 eine Frontansicht im Schnitt des Heizgeräts mit Trennwand im Wasserraum und Wasserflussregler in dieser Trennwand,
• 3 ein Detail des Reglers von 1,
• 4 eine Seitenansicht im Schnitt des Heizgeräts mit Wasserflussregler am Eingang zum Heizgerät,
• 5 eine Frontansicht im Schnitt des Heizgeräts mit Wasserflussregler am Eingang zum Heizgerät und
• 6 ein Detail des Reglers von 4.

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

• 1 a side view in section of the heater with partition in the water chamber and water flow regulator in this partition,
• 2 a front view in section of the heater with partition in the water room and water flow regulator in this partition,
• 3 a detail of the regulator of 1 .
• 4 a side view in section of the heater with water flow regulator at the entrance to the heater,
• 5 a front view in section of the heater with water flow control at the entrance to the heater and
• 6 a detail of the regulator of 4 ,

Embodiment of the heater - carburettor boiler for firewood with a partition in the water space and a water flow regulator in this partition wall, Fig. 1 to 3

The boiler includes in the upper part of the filling chamber 11 whose walls are covered with an inner shell 12 provided in the lower part with a ceramic lining 19 is designed. Between the inner jacket 12 and the heat exchange surfaces is an air gap 13 , In the lower part of the boiler is the afterburning chamber 9 surrounded by a ceramic lining 19 , The filling chamber 11 and the afterburning chamber 9 are with an opening - nozzle 3 - connected. The afterburning chamber 9 is with an exhaust gas exchanger 5 Some vertical channels form in the upper part of the flue 1 lead.

The water room 2 of the boiler includes a distributor at approximately 1/4 of the boiler height 18 What is the room with a rectangular base, bounded in the lower part with the sheet metal 8th , in the upper part with the ground 4 the filling chamber 11 and in the vertical direction with side walls 7 , In one of the side walls 7 of the distributor 18 the water inlet opens 15 , The side walls 7 and the bottom sheet 8th of the distributor 18 include mixing holes 14 standing in the water room 2 of the boiler. In the described embodiment, all mixing ports 14 equal and circular with a diameter of 7 mm. Their total number is about 100. The arrangement of the individual mixing openings 14 corresponds to the intensity distribution of the heat output. The densest are the mixing holes 14 in the lower plate 8th of the distributor 18 in the vicinity of the opening - nozzle 3 - arranged because they are in the part of the water space 2 with heat exchange surfaces of the post-combustion chamber 9 open, where the heat output is the most intense.

The water room 2 is about 1/4 of the height, just above the distributor 18 through a partition 6 separated. The water room 2 below the partition 6 is of heat exchange surfaces of the afterburner 9 with high power intensity and the first part of the flue gas exchanger 5 surround. The water room 2 above the partition 6 is, however, of heat exchange surfaces of the filling chamber 11 and the middle and upper part of the exhaust gas exchanger 5 surrounded, which are heat exchange surfaces with low power intensity. On the front wall of the boiler is located in the partition 6 a flow opening 16 with water flow regulator 17 based on the water temperature in the water space below the dividing wall 6 , The water flow regulator 17 In the exemplary embodiment, a paraffin thermostat with an opening temperature of 60 ° C., which consists of a container with paraffin 24 consists of a piston 23 is with one stone 22 connected is. The flap 22 is (down) by a spring 21 pressed. The paraffin container 24 is in the water room 2 below the partition 6 in a bed 25 arranged.

The function of the example embodiment described is as follows:

Combustion air is fed into the boiler. This flows through the air gap 13 and enters the fuel layer in the filling chamber 11 where the primary combustion (gasification) takes place. The resulting gases flow through the opening - nozzle 3 - Where the combustion air is supplied, causing their combustion. The gases flow into the afterburning chamber 9 where they burn. The resulting exhaust gases flow behind the ceramic lining 19 in the Abgasaustau shear 5 and from there into the exhaust vent 1 , By the primary combustion in the filling chamber 11 Heat is released, which is the inner shell 12 heated and this heated, mainly by heat dissipation, the heat exchange surfaces, the filling chamber 11 surround. The flame and the exhaust gases transfer the heat to the heat exchange surfaces that make up the afterburning chamber 9 and the exhaust gas exchanger 5 surrounded, and the heat exchange surfaces transfer the heat to the water in the water space 2 of the boiler.

The heat transfer medium - the water, z. B. with a temperature of 20 ° C - flows through the water inlet 15 in the distributor 18 and from there enters the mixing holes 14 in the water room 2 below the partition 6 where the water temperature is approx. 60 ° C. Because the mixing holes 14 are small, the water flowing from them mixes quickly with the water in the water 2 below the partition 6 , Because the arrangement density of the mixing holes 14 the power intensity of individual parts of the water space 2 below the partition 6 corresponds, the water temperature is in the entire volume of the water space 2 below the partition 6 about the same. The water continues to flow through the flow opening and flushes the container with paraffin 24 and the water flow regulator 17 from. If z. B. the burning power and thus the performance of the heat exchange surfaces increases, the water temperature rises in the water 2 of the boiler, and the temperature of the water, which is the water flow regulator 17 rinses above 60 ° C. As a result, the paraffin melts, increases its volume and pushes the piston 23 out, the flap up 22 opens. This increases the water flow through the flow opening 16 and thus also the supply of the cold input water from the distributor 18 in the water room 2 below the partition 6 , which reduces the water temperature in the boiler. Conversely, when the burning power decreases, the water temperature in the water chamber drops 2 the boiler, the paraffin gets stuck, the piston 23 is due to the pressure of the spring 21 in the container 24 pressed with paraffin and closes the flap 22 in the direction down. This reduces the flow of water through the flow opening 16 and thus also the supply of cold input water from the manifold 18 in the water room 2 , which increases the water temperature in the boiler. By the above described operation keeps the water flow regulator 17 the temperature at the flow opening 16 and therefore also in the water area 2 below the dividing wall 6 at the value of 60 ° C.

The water flowing through the flow opening 16 flows, continues through the water 2 the boiler above the partition 6 and is through the heat exchange surfaces of the filling chamber 11 and the middle and upper parts of the exhaust gas exchanger 5 to the value of z. B. 75 ° C heated. So heated water then flows through the water outlet 10 from the kettle.

The water room 2 below the partition 6 surrounds the heat exchange surfaces, through which about 70% of the total heat output is transferred to the water. Therefore, the water is heated here, for example, from 20 ° C to 60 ° C, ie by 40 ° C. Above the dividing wall 6 Surround heat exchange surfaces with lower power intensity, which transfers about 30% of the total power to the water, the water space 2 , Therefore, here is the water z. B. heated to about 15 ° C, which is from 60 ° C to 75 ° C. If the boiler water with a temperature of z. B. 40 ° C, it is in the water 2 below the partition 6 warmed again to 60 ° C, ie around 20 ° C. In the water room 2 above the partition 6 it is then heated to about 5 ° C to 65 ° C.

The advantage of this design is that thanks to the partition 6 the use of a simple water flow regulator 17 with temperature sensor (container 24 with paraffin) in the same place as the flow opening 16 allows. Another advantage of this design is that it has two water inlets 15 structurally simple, for example, on the right and left side of the boiler, which increases the connection variability.

Embodiment of the heater - carburettor boiler for firewood with a water flow regulator at the boiler inlet, 4 to 6 ,

This design is the same as the previous version, except that the water room 2 the boiler no partition 6 contains and the flow opening 16 with water flow regulator 17 behind the water entrance 15 located. In this embodiment was as a water flow regulator 17 also used paraffin thermostat, but with the difference that the paraffin container 24 in the water room 2 so below the distributor 18 is that the piston 23 through the bottom sheet 8th of the distributor 18 comes through.

The function of the second embodiment is practically identical to that of the first embodiment.

The advantage of this design is that it does not have a partition 6 must contain. However, it requires a water flow regulator 17 with temperature sensor - container 24 with paraffin - which is not at the flow opening 16 is arranged. The piston 23 must therefore move through the wall, which is the water flow regulator 17 technically demanding. Another limitation of this design is that the boiler has only one water inlet 15 Has.

The designs of the heaters may differ depending on the type of heater used. The solutions can be used with virtually any type of heater that heats the water, such as boilers, stoves or ovens with water heat exchangers, etc.

The shape and arrangement of the distributor may be different 18 be. For example, it may have the shape of a torus, arch, etc., depending on the design of the heater.

Also the mixing holes 14 can be different, they can have the shape of a rectangle or oblong slot.

In different solutions, there may be more flow openings 16 not all give the water flow regulator 17 must contain. Openings without water flow regulator 17 can ensure a minimum constant flow, z. B. to dissipate the residual heat after the fuel combustion (if no risk of corrosion), etc.

On the other hand, also the water flow regulator 17 contained, if instead of the paraffin thermostat z. As an oil or bimetallic thermostat or another automatically controlled valve or a flap can be used.

The partition 6 may be in another part of the water space 2 of the heater depending on the design of the heater.

It is also a version without partition 6 possible, being as a flow opening 16 the water outlet 10 or the water entrance 15 can be used.

The controller may contain a detector element (sensor) and an active element (drive the flap) separately, for. B. capillary thermostat.

LIST OF REFERENCE NUMBERS

1

exhaust hood

2

water space

3

Opening - nozzle

4

ground

5

exhaust gas exchanger

6

partition wall

7

Side wall

8th

Lower sheet

9

afterburner chamber

10

water output

11

filling chamber

12

inner sheath

13

air gap

14

mixed opening

15

water input

16

Flow opening

17

Water flow regulator

18

distributor

19

Ceramic lining

20

thermal insulation

21

compression spring

22

flap

23

piston

24

Container with paraffin

25

bed

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0693661 [0009]

Claims (3)

A heat-conducting heater with integrated automatic water mixture for protection against low-temperature corrosion, comprising a water inlet (15) opening in the distributor (18), wherein the distributor (18) comprises at least one mixing opening (14), which opens into the water space (2) of the heater, characterized in that the water space (2) of the heater between the water inlet (15) and the water outlet (10) is reduced to at least one flow opening (16) with a water flow regulator (17). Heat conducting heater after Claim 1 characterized in that the water space (2) of the heater comprises a partition wall (6) with at least one flow opening (16) with water flow regulator (17). Heat conducting heater after Claim 1 or 2 , characterized in that the water flow regulator (17) consists of a container (24) with paraffin in which there is a piston (23) connected to a flap (22), the container (24) containing paraffin in the Water room (2) is located

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