DE102013114388A1 - Temperature difference measuring device - Google Patents

Abstract

Temperature difference measuring device (1) with a first and a second sensor for determining the temperature, wherein the first and the second sensor are arranged in a common measuring insert (11), wherein the first sensor partially in a first serving as a first measuring tip extension (2 ) of the measuring insert (11) is arranged, and wherein the second sensor is arranged in a second serving as a second measuring tip extension (3) of the measuring insert (11).

Description

The invention relates to a temperature difference measuring device, a use of the temperature difference measuring device, a heating element, a boiler, and to a method for determining temperature difference.

For heat generation burners are nowadays used, which burn, for example, suitable for heat generation fuels. Alternatively, it can generally be a heating element, such as, for example, an electric heating element act. A corresponding technical device is called firing.

For example. is from the patent DE 602005006149 T2 a boiler and a boiler control unit become known. Boilers for heating the premises of a building and / or for providing hot water from a faucet are usually controlled by a thermal relay providing on / off temperature control.

Moreover, from the publication EP 651873 discloses a power stroke delay control unit for heating a boiler, which is equipped with a burner, which burner on and off is controllable.

The publication DE 10057942 discloses a boiler control unit for controlling a heater in a boiler including a power stroke retardation controller to activate or deactivate the heater, wherein the power stroke delay control unit is actuated by a thermal relay that provides a temperature responsive signal and turns on when the temperature in the boiler is high Boiler falls below a lower temperature level, and switches off when the temperature in the boiler exceeds a higher temperature level.

Furthermore, for example, in the patent DE 602005006149 T2 Burner shown on an outer wall through which the burner is separated from the water tank, which is transmitted through this outer wall, the heat generated by the burner to the water tank.

In addition, it has become known from the prior art to attach a thermometer to a stovepipe.

In the present case, however, the problem arises that at the burner, where the heat is generated, for example, lime deposits on the outer wall of the burner. Such deposits lead to a higher burner temperature necessary so that, for example, apply the same steam conditions. Thus, it is not recognized, for example, for a long time that these steam conditions are achieved with an increased energy requirement and thus inefficiently.

This problem is solved by the present invention in the form of a temperature difference measuring device, a heating element, a heating boiler, and a method for temperature difference determination.

With regard to the temperature difference measuring device, the object is achieved by a temperature difference measuring device having a first and a second sensor for determining the temperature, wherein the first and the second sensor are arranged in a common measuring insert, wherein the first sensor partially in a first as the first Measuring tip serving extension of the measuring insert is arranged, and wherein the second sensor is arranged in a second serving as a second measuring tip extension of the measuring insert.

The measuring device thus comprises at least the measuring insert, which contains two sensors. These sensors preferably have a sensor element at one end thereof. This sensor element is then arranged in the respective extension. The remaining connecting lines of the first and second sensors are then arranged in a common, for example. Elongated body of the measuring insert.

For example, the first and second sensors may be partially embedded in a ceramic material.

As a measuring insert while the component of a measuring device is called, which is intended to come into contact with the medium in contact.

Preferably, the first and the second extension may have a certain predetermined distance. This distance can be determined by the geometry, i. H. be determined by the shape of the measuring insert. The measuring insert has for this purpose, for example, a fork, in particular at its end, which fork is formed by the two extensions.

In one embodiment of the measuring device, the surface properties of the first and of the second extension differ from one another, at least in a partial area of the surface of the first and the second extension, in particular with respect to their hydrophobicity.

In a further embodiment of the measuring device, the first and the differ second extension with respect to their geometric shape from each other, wherein in particular the second extension has a conical or wedge-like shape.

In a further embodiment of the measuring device, the second measuring tip is thermally decoupled from the first measuring tip, in particular spaced from the first measuring tip or the first extension.

In a further embodiment of the measuring device, the first and second sensors serve to determine a temperature difference between the first measuring tip and the second measuring tip.

With regard to use, the object is achieved by the use of the temperature difference measuring device for detecting deposits on an outer wall of a heating element, such as a burner, which outer wall is used for heat transfer to a medium to be heated.

With regard to the heating element, the object is achieved by a heating element, in particular a burner, for firing on heating or steam boilers with a temperature difference measuring device according to one of the previous embodiments, wherein the heating element has an outer wall, which serves for heat transfer to a medium to be heated wherein the first measuring tip is disposed on the outer wall, and wherein the second measuring tip is spaced from the outer wall.

In a further embodiment of the heating element, the second measuring tip is arranged and / or shaped and / or at least a part of the surface of the second measuring tip is such that the second measuring tip remains substantially free of deposition by the action of gravity, the deposition For example, by precipitation of a substance from the means of the burner to be heated medium.

With regard to the boiler, the object is achieved by a boiler for heating a medium with a heating element according to one of the previous embodiments.

With regard to the method, the object is achieved by a method for temperature difference determination, in particular for detecting deposits on the outer wall of a heating element, in particular a burner, wherein a first temperature at a first measuring tip is determined by means of a first sensor, wherein by means of a second sensor a second temperature is determined at a second measuring tip, wherein the first and the second sensor are arranged in a common measuring insert, and wherein the first and the second temperature are compared and wherein in the case of a deviation is above a predetermined threshold, a corresponding message, the Specifically indicates a deposit on the outer wall of a heating element is generated.

In one embodiment of the method, a detection of a deposit on an outer wall of a heating element takes place independently of other, in particular detected at another location, temperature, in particular of the heated medium.

The invention will be explained in more detail with reference to the following drawings.

It shows:

1 an embodiment of the temperature difference measuring device with a measuring insert having a first and a second extension, in each of which a sensor is arranged, and

2 : a connection head connected to the measuring insert.

1 shows a temperature difference measuring device 1 in which a first sensor in the form of a skin thermometer in thermal contact on a wall 4 , as, for example, the inside of a heating tube, is attached. The first sensor is partially in a first extension 2 of the elongated measuring insert 11 arranged. Thus, a part of the first sensor, in particular its sensor element or measuring point, is located within the first extension 2 , while, for example, connecting lines of the first sensor in the elongated body of the measuring insert 1 are arranged.

Furthermore, the temperature difference measuring device 1 a second sensor, in a second extension 3 of the elongated body of the measuring insert 1 is arranged.

The temperature difference measuring device shown 1 or the measuring insert 11 is particularly advantageous because metallic surfaces, ie steels with metallic oxide layers, which are used as surfaces of heating elements in

Waters of a certain medium to high degree of hardness protrude, ie German hardness dH = 14 - 21 ia experience in the heating operation lime deposition. The local heating of a lime-containing, ie calcium bicarbonate-containing water ia carbon dioxide is released from the thermally shifted hydrolysis equilibrium of calcium bicarbonate, resulting in a Calcification by precipitating calcium carbonate leads. If the metal surface is already covered with calcium carbonate deposits, further limescale deposits can lead to calcification in the centimeter range. Such encrustations should be recognized independently of temperature differences within a Heizwasserkreislaufes.

The outer wall shown here 4 can serve, for example, as a heat exchanger to the heat of a burner gas flow (in the interior of the wall 4 ) to a medium to be heated (outside the wall 4 ) transferred to. The skin thermometer - as the first extension 2 of the measuring insert - may consist of a material with similar lime-settling properties as the outer wall, so be, for example, metallic.

In addition to the first temperature measurement by means of the first sensor, such as the o. G. Skin thermometers, a second is now in the medium to be heated, such as. Hot water protruding sensor used.

The second sensor is thermally decoupled from the first sensor, ie the skin thermometer, and is, for example, at least six times the diameter of the second extension 3 from the first extension 2 , here in the form of the skin thermometer, spaced and protrudes in the installed state into the medium to be heated.

The surface of the second extension 3 consists, at least partially, for example, of a nonpolar preferably hydrophobic material such as, for example, fluoropolymer, which have no deposition affinities against lime.

Should there be limescale precipitations despite the thermal decoupling of the second sensor, the lime that is just precipitating will not be on the surface of the second extension 3 stick to it, but slide into the ground.

The evaluation of the temperature difference between the first sensor and the second sensor provides a benchmark, eg. Depending on the known heating rate, for the detection of limescale independent of any temperature differences within the Heizwasserkreislaufes whose temperature is detected, for example. At a third location, the place the first and second thermometer device is distinguished.

Usually, the first sensor with the attached second sensor is arranged on the side of the heating tube around which hot water flows, preferably at a point filled with hot water directly above the burner or oven chamber or via the electrical resistance or electro-inductive heated oven device.

Like in the 1 the measuring device can be attached to the wall of the heating element at least along part of the circumference of the wall or, depending on the piping arrangement, to the side of a heating tube or to other vessels or boiler devices serving for water heating.

2 shows one to the in 1 subsequent part of the temperature difference measuring device 1 or the measuring insert 11 , The measuring insert has at least one turn to compensate for heat-related changes in length.

The measuring insert 11 is through a process connection 7 guided and over a neck piece 8th on a connection head 9 outside the tank, for example a boiler, connected. The temperature difference measuring device 1 So it can be next to the measuring insert 11 also a process connection 7 , a throat piece 8th and / or a connection head 9 or have head transmitter.

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

• DE 602005006149 T2 [0003, 0006]
• EP 651873 [0004]
• DE 10057942 [0005]

Claims (11)

Temperature difference measuring device ( 1 ) with a first and a second sensor for determining the temperature, wherein the first and the second sensor in a common measuring insert ( 11 ) are arranged, wherein the first sensor partially in a first serving as a first measuring tip extension ( 2 ) of the measuring insert ( 11 ), and wherein the second sensor is used in a second extension (FIG. 3 ) of the measuring insert ( 11 ) is arranged. Measuring device ( 1 ) according to the preceding claim, wherein the surface condition of the first and the second extension ( 2 . 3 ) at least in a partial region of the surface of the first and the second extension ( 2 . 3 ), in particular with regard to their hydrophobicity. Measuring device ( 1 ) according to one of the preceding claims, wherein the first and the second extension ( 2 . 3 ) in terms of their geometric shape, in particular, the second extension has a conical or wedge-like shape. Measuring device ( 1 ) according to one of the preceding claims, wherein the second measuring tip is thermally decoupled from the first measuring tip, in particular from the first measuring tip or the first extension ( 2 ) is spaced. Measuring device ( 1 ) according to one of the preceding claims, wherein the first and the second sensor serve to determine a temperature difference between the first measuring tip and the second measuring tip. Use of the temperature difference measuring device ( 1 ) for the detection of deposits on an outer wall ( 4 ) of a heating element ( 5 ), eg. a burner, which outer wall ( 4 ) is used for heat transfer to a medium to be heated. Heating element ( 5 ), in particular burners, for firing on heating or steam boilers with a temperature difference measuring device ( 1 ) according to one of claims 1 to 5, wherein the heating element ( 5 ) an outer wall ( 4 ), which serves for heat transfer to a medium to be heated, wherein the first measuring tip is arranged on the outer wall, and wherein the second measuring tip is arranged at a distance from the outer wall. Heating element ( 5 ) according to the preceding claim, wherein the second measuring tip is arranged and / or shaped and / or the at least part of the surface of the second measuring tip is such that the second measuring tip remains substantially free of deposition by the action of gravity, wherein the deposit, for example, comes from precipitation of a substance from the medium to be heated by means of the heating element. Heating boiler for heating a medium with a heating element ( 5 ) according to one of claims 7 and / or 8. Method for temperature difference determination, in particular for the detection of deposits on the outer wall ( 4 ) of a heating element ( 5 ), in particular a burner, wherein a first temperature at a first measuring tip is determined by means of a first measuring transducer, wherein a second sensor is used to determine a second temperature at a second measuring tip by means of a second sensor, wherein the first and the second sensor in a common measuring insert ( 1 ) are arranged, and wherein the first and the second temperature are compared and wherein in the case of a deviation which is above a predetermined threshold, a corresponding message, in particular a deposit on the outer wall ( 4 ) of a heating element ( 5 ) is generated. Method according to the preceding claim, wherein a detection of a deposit on an outer wall ( 4 ) of a heating element ( 5 ) is carried out independently of other, in particular detected at another point, temperature, in particular of the heated medium occurs.

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