CZ138193A3 - Apparatus for the preparation of hot water - Google Patents

Abstract

In catalytic combustion, a fuel gas/air mixture burns when it comes into contact with a catalytic layer. Combustion takes places without flames at temperatures of between 800 and 1000 DEG C. To initiate the reaction, a stand-by temperature of about 300 to 350 DEG C must be achieved. For this purpose, the fuel gas/air mixture should be preheated. Preheating is effected either by means of a gas burner (8), the combustion chamber (7) of which is arranged underneath the distribution chamber (6) of the catalytic burner (2), or by means of a premix burner (14, 15), which is mounted in an internal pipe (3) of a catalytic pyrolysis burner (2). After preheating, it is possible, for relatively low output requirements, to operate the pyrolysis burner (4) alone or, for higher requirements, to operate the premix burner (14, 15) as well. <IMAGE>

Description

Technical field

The invention is in the field of hot water supply systems. Heat for heating is obtained by catalytic combustion. Preheating and self-heating are solved.

BACKGROUND OF THE INVENTION

A water heating device of this kind is German Patent DE-PS 251 5 7. Catalytic burners are located in the water space to allow flame-free combustion on the catalyst bed. The combustion there occurs in such burners, at relatively low temperatures between 800 and 1000 ° C, and? S which avoids the formation of nitrogen oxides _ΝΟ χ · The burners described in this patent, the glasses can be of porous burner tubes which are on the outer side with a catalyst layer through which the fuel gas is forced from the inside out. On the surface, they combine with the combustion air flowing around them and burn * without burning as soon as the ignition temperature is exceeded. The burner itself serves as a preheating device in which the fuel gas first flowing is burned by an open flame. When the catalyst is sufficiently heated, the gas supply is briefly interrupted and the catalytic combustion process is subsequently introduced.

[0007] The previously unpublished patent application P 42 2 711.913 also discloses a catalytic burner with a preheating device which is itself maintained in operation by fuel gas.

In this case, the catalytic burner is designed as a bug burner between the hollow body and the water jacket. The preheating device comprises a gas burner arranged at the inlet end of the catalytic burner. Its combustion gases flow through the inner hollow body until it reaches a temperature of approximately 3 ° - 350 ° C. Then the fuel gas / air mixture is switched to a catalytic burner.

Summary of the Invention _#

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus for the preparation of hot water 3 by a catalytic burner in which efficient preheating takes place and which responds flexibly to various performance requirements.

The inventive principle of the water heater is that the preheating device comprises a gas burner arranged at the inlet end of the burner or a premix burner arranged in the burner, where the combustion gases transfer their heat through the heat exchanger wall to the mixture of fuel gas and air in the catalytic combustion space.

The known serial connection of the preheating burner and the catalytic burner could not be completely excluded from DE-PS 251 5 57 because of the combustion in both cases taking place on the same side. According to the invention, however, the two regions are deliberately separated by the wall of the heat exchanger. In particular, the use of a premix burner not only leads to optimum low-emission combustion which would damage the environment, but also ensures that the desired operating temperatures of the catalytic burner are achieved very quickly. Indeed, the premix burner comprises a straight hollow burner body serving as a combustion chamber and thus brings it to the desired temperature in the shortest possible time.

The gas burner or premix burner can only be used to preheat the catalytic burner in a known manner. For this purpose, it can be automatically blocked by a change-over valve from the fuel-gas mixture supply when an operating temperature of about 300 to 350 C has been reached.

A particular advantage, however, is that, in particular, the premix burner is operated together with the catalytic burner at an increased power requirement. In this case, the catalytic burner can, in a modulated mode of operation, cover the basic heat demand of a house with low energy consumption. However, as soon as peak heat demand occurs, a pre-mixing burner is additionally connected to, for example, the tap water. The premix burner has a dual function. It is used to start the catalytic burner and to cover peak loads.

It is recommended to use a catalytic burner in a modulated manner. Thus, for example, between 6 and 12 kW, the basic heat demand of the house could be met continuously, and a pre-mixing burner of, for example, 13 kW can be additionally connected to the domestic water supply, while the catalytic burner can be modulated way. In this way, the entire power range can be covered continuously up to the peak load.

In a practical embodiment, it is recommended to construct the burner and the two interposed tubes to create combustion acx gaps. In one premix burner, which preheater device the inner tube serves as the combustion chamber of the preheating burner. For a certain pressure equalization, it is recommended that the pipe be made of porous material.

When using a gas burner as a preheating device, a distribution chamber of the fuel gas / air mixture leading to the combustion gap of the catalytic burner is arranged below the water space and a combustion chamber of the gas burner is located beneath the distribution chamber. The mixture of fuel gas and air enters the manifold chamber and from there the gaps or gaps of the catalytic burner. It can be fed to the combustion chamber of the gas burner via a pre-changeover valve. Here it ignites and carries out burning by visible flame. The heating gases produced here heat up the separation wall, which is also the support of the catalyst layer.

When the reaction temperature is reached, the supply to the gas burner is closed. In this case, the inner tube serves as a gas channel for the heating gases of the gas burner.

Summary of drawings in drawings

Two embodiments of the invention are shown in the drawings.

'*

They show:

OBB. 1: Vertical section of a water heater with a J ^3ic0 gas burner preheater.

OBB7 2: Enlarged viewport of FIG7 1,

9BR, 3ϊ Vertical section of water heater with premix burner as preheater

4: The cutout of FIG. 3 with a surface premix burner

The combustion chamber 11 is formed in the space 1, which has a larger number of burners 2 with concentrically arranged tubes 4. In the tubes, a combustion gap 11 is formed in which the mixture of fuel gas and air flows catalytically at temperatures between 800 and 1000 ° C. flame burns ·

To achieve this reaction, a catalyst layer is preferably applied to the inner tube 2. Through the outer tube 4, heat is transferred to the surrounding water in the science space 1.

To initiate the reaction at about 300 ° C - podle according to OBB. 1 and FIG. Z is below the distribution chamber 6 of the cleavage catalytic burner Z, the space 2 of the gas burner burners 8 with the distribution grid 2, the ignition electrode 10 and the flame monitoring device 11. The gas burner 8 is supplied with a mixture of heating gas and air through the supply line 12 after the valve 13 has been switched. The gas produced is flowing through the inner pipe 2 and heated. This inner tube 2 forms the wall of the heat exchanger towards the catalytic space of the burners. Once the reaction temperature was reached, the liner burner was disconnected for 2 ^seconds .

Referring to FIG. 3 and 4, a cylindrical premix burner 14 or a flat premix burner 15 is disposed in the inner tube 2 of the cleavage catalytic burner 2. The inner space of the inner tube 2 forms the firing chamber of the premix burner and the wall of the heat exchanger to the catalytic space of the burners ^{. With} both tubes 3 and

4. Valve 13 with inlet 1? air and gas inlet 13 can only operate a pre-mix burner 14 or 15 or a cleavage catalytic burner 2 ^{and a} burner 14 or 15 or 2 at peak demand. »to předraísícxho burner flue gas cylinder 14 does not accumulate in the front zone, it is recommended to make the inner tube 2 ^of porous materiálu.Vznikne of that pressure compensation above the flow channel of .štšpící catalytic burner ⁱⁿ the second

Industrial applicability

The method of industrial applicability follows from the preceding parts of the invention.

Claims (7)

PATENT O N S Ο Κ ϊ 1. Equipment for preparation; hot water, the water space of which has at least one catalytic burner (?) for combustion of the gas-air staircase to the catalytic trstr. a burner (8) disposed at the inlet end of the catalytic burner (2) or a cylindrical premix burner (14) or a surface transfer burner (15) disposed in the catalytic burner (2), their combustion gases transfer their heat through the exchanger wall r- . · ·· on the mixture of fuel gas and air in the catalytic combustion space. Hot water preparation device according to claim 1, characterized in that the gas burner (8) or the cylindrical pre-burner (14) or the flat premix burner (15) is supplied with a mixture of fuel gas and air of the catalytic burner (2). the inlet of the mixture is automatically blocked when the operating temperature - preheating - of about J00 - 550 ° C has been reached, which is sufficient for catalytic combustion of the mixture of fuel gas and air. Device for preparing hot water according to claim 1, characterized in that the gas burner (8) and in particular the cylindrical pre-mix burner (14) or the flat pre-mix burner (15) is supplied with a mixture of fuel gas and air of the catalytic burner (2). the increased power demand is operated together by a catalytic burner (2) to cover peak load. 4 »Hot water preparation device according to claim 5, characterized in that the catalytic burner (2), after preheating in modulating operation, covers the basic heat demand and that the cylindrical displacement burner (14 / 5i flat-burner / 15) is additionally connected at increased heat demand as for domestic water consumption. A hot water preparation device according to claim 4, characterized in that the catalytic burner (2) is also modulating in order to achieve a continuous adaptation of the output, even with an additionally connected cylindrical pre-burner (15) or a flat pre-burner (15). way. The hot-water preparation device according to claim 1, characterized in that the catalytic burner (2) for the formation of a combustion lake (5) consists of two tubes (3, 4) inserted into each other, wherein the inner tube (3). it serves as a combustion chamber of a cylindrical premix burner (14) or a flat premix burner (15) and is made of a porous combustion gas permeable material of a cylindrical premix burner (14) or a flat premix burner (15). The hot water preparation device according to claim 6, characterized in that the cylindrical premix burner (14) or the flat premix burner (15) is formed as a longitudinally extending burner tube in the inner tube (3) of the catalytic burner (2). A hot water preparation device according to claim 6, characterized in that the cylindrical premix burner (14) or the flat premix burner (15) is configured as a flat burner arranged at the inlet of the inner tube (3) of the catalytic burner (2). Device for hot water preparation according to claim 1, characterized in that a distribution chamber leading to the combustion gap (5) of the catalytic burner (6) is arranged below the water space (1) and is disposed therein by means of this distribution chamber (6). space / gas burner burners / 8 /. 1Ó. A water supply device according to claim 9, characterized in that the catalytic burner (2) for forming the combustion gap (5) consists of two tubes (3, 4) inserted, the inner pipe (3) serves as the gas channel of the gas burner (8) and is led through the manifold chamber (6) to the burner space (7) and the outer pipe (4) extends from the water space (1) up to the manifold chambers (6). --—-