Heat flow sensor

Abstract

The present invention relates to a heat exchanger comprising a plurality of exchange tubes (1) mounted joined longitudinally in such a way as to create a front surface portion (4) creating an obstacle to an incident heat flow and at least one heat flow sensor (5) disposed in a support (12) located between two adjacent exchange tubes (1), characterized in that the support (12) of the heat flow sensor (5) is brazed to at least one of the two tubes (1) and is flattened on the side that is to be disposed at the front (4), with reference to the incident heat flow, in such a way as to be able to be inserted between the two adjacent tubes (1) at the location of said local deformations (11).

Claims

1. A heat exchanger comprising at least two exchange tubes (1) contiguously mounted longitudinally so as to create a front surface portion (4) forming, in use, an obstacle to an incident heat flow and at least one heat flow sensor (5) disposed in a support (12) located between the two adjacent exchange tubes (1), wherein: the two adjacent tubes (1) each have, at their contiguous portion, a slight local deformation (11), in such a way as to allow the positioning of the heat flow sensor (5) support (12) by insertion between the two tubes; the heat flow sensor (5) inserted through an opening of the support opposite the front surface portion and is mounted movably in said support (12), said support having the shape of a hollow enclosure made in such a way as to be able to be inserted between the two adjacent tubes (1), at the location of said local deformations (11); and characterized in that the support (12) of the heat flow sensor (5) is brazed to at least one of the two tubes (1) and is thinned longitudinally on the side that is to be disposed at the front surface portion (4), said front surface portion being defined with reference to the incident heat flow existing in use, so as to be able to be inserted between the two adjacent tubes (1) at the location of said local deformations (11).

2. The heat exchanger according to claim 1, characterized in that the heat flow sensor (5) comprises a removable part that is inserted from a rear surface portion (3), said rear surface portion being defined with reference to the incident heat flow existing in use, and is screwed into said support (12) toward the front surface portion (4), thus ensuring thermal contact between the sensor (5) and the support (12).

3. The heat exchanger according to claim 2, characterized in that the heat flow sensor (5) comprises a front tip (6) and a body (7) where the temperature measurements will be respectively done making it possible to obtain, in use, a temperature difference for the measurement of the heat flow.

4. The heat exchanger according to claim 1, characterized in that the slight local deformation (11) is a deformation done by press.

5. A solar power unit with thermodynamic concentration comprising a boiler provided with a heat exchanger according to claim 1.

6. A solar power unit with thermodynamic concentration comprising a boiler provided with a heat exchanger according to claim 2.

7. A solar power unit with thermodynamic concentration comprising a boiler provided with a heat exchanger according to claim 3.

8. A solar power unit with thermodynamic concentration comprising a boiler provided with a heat exchanger according to claim 4.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a perspective view of an exchange panel tube equipped with a through tube designed for the installation of a heat flow sensor, according to the state of the art.

(2) FIG. 2 is a sectional view of a heat flow sensor installed according to the through tube technology of FIG. 1.

(3) FIG. 3 diagrammatically shows the technology for installing thermocouples in a local deformation of an exchange tube with weld deposit overlay, according to the state of the art.

(4) FIG. 4 shows the local stresses resulting from the use of the through tube technology of FIG. 1.

(5) FIGS. 5A and 5B respectively show a cross-sectional view and perspective view of a heat flow sensor in position in its support on the exchange tubes according to one particular embodiment of the present invention.

(6) FIG. 6 is a side schematic view of a solar power unit with thermodynamic concentration comprising a boiler.

DESCRIPTION OF ONE PREFERRED EMBODIMENT OF THE INVENTION

(7) The idea at the base of the present invention consists in installing the heat flow sensor between two tubes of the exchange panel, without seal break, without producing pressurized welds and with as little machining or deformation of the tubes as possible. The invention is in particular directed to a heat exchanger application where the exchange tubes are joined, optionally with slight play, with no junction fin between the tubes.

(8) To that end, as shown in FIGS. 5A and 5B for one example embodiment, a very slight local deformation 11 of the two tubes 1 will be done by press. A sensor support 12, essentially in the form of a tube flattened on one side, will then be installed between the two exchange tubes 1 and brazed to one of the exchange tubes 1 in order to ensure maintenance of the support, but also proper cooling thereof by the fluid flowing in the exchange tube. The sensor 5 will be inserted into the support 12 from the rear, relative to the incident solar flow, and screwed to the support 12. The sensor 5 advantageously comprises a conical part (not shown) adapting to the inside of the support 12, embodying the contact between the sensor 5 and the support 12 cooled by the tube 1 on which the latter is brazed.

(9) As in the technologies of the state of the art, the heat flow will be the image of the temperature difference between the tip of the sensor and the body thereof, which is cooled by the fluid flowing in the tube.

(10) The solution provided by the present invention is non-intrusive, does not cause any risk for the tube and has the advantage of not requiring additional pressurized welding. Furthermore, as in the through tube solution, the sensor can be removed from the rear and can easily be replaced.

REFERENCE SYMBOLS

(11) 1. exchange tube 2. through tube, heat flow sensor support 3. rear part of the exchange tube 4. front part of the exchange tube 5. heat flow sensor 6. sensor tip 7. sensor body 8. local tube deformation 9. weld cladding containing the thermocouples 10. local stress 11. deformation/flat in the exchange tube 12. sensor support