LU87177A1 - THERMO-INDUCTION HOT FLUID GENERATOR - Google Patents

Description

• 1 Ç> "7 A“ 7 * 7 GRAND-DUCHY OF LUXEMBOURG BL-4098 / m,. Patent N "Ο ../ I ........... The Mummy"! The Minister of ........... 23 March ....... 1988 ...................._ ϊΨλχί · of the Economy and of Middle Classes - = ¾¾¾ Intellectual Property Service

Book title ..........................-.......— (¾¾ LUXEMBOURG r-

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Request for an Inv ^ çT ^ ty ^ ................... 7 ~ n Z 06 ΓΤΓΊ ^

I. Request Ȕzsichn, I

...... I "a ..... society ..... called ....... r — EMNGE ..... gBAMSEQ" ..... Way ..... ΚοτΜ ^ ηβ ·; ......----------------- (...................... .....................................-............ .................................................. .................................................. .......................-..... LES-METZ ---------- FRINGE ------- ---------------------------------------------------------- ---- ...... E.epx.és.ent.ee „........ p.ar ......; ...... Ernest ..... MEYERS ...... and ~ Ernest .....- T- · ....... EREYLINGIR — Ing * ...... eons * ......... (3) ...... SB ..... own »...... ind.iA ...... 46 ..... rm .... du ..... cemetery * .. .... LUXEMBOURG, ...... agents, .................................... ...........................

deposit (s) this ................. twenty ...... three ..... March ..... mil ...... new. .... one hundred and four ..... twenty-eight ------------------------------------ -------- (4) at ...... 15, QQ ..... hours, at the Ministry of the Economy and the Middle Classes, in Luxembourg: 1. this request for the obtaining a patent for an invention concerning: ........................................ .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ............... (5) "Generator ..... of ...... fluid ..... hot ..... to-therm" ·· ..... indnetion · "..............-........................... .................................................. .......-..............................— 2. description in language ..... .................... French ............................. .....................of the invention in triplicate; 3 .......................... 2 ...................... .................... drawing boards, in triplicate; 4. the receipt of the taxes paid to the Registration Office in Luxembourg, 23 _., March 19.8.8 ........................; 5. the delegation of power, dated kk.8 .............. on ________ 1.6 March 1.9.88 --------; 6. the successor document (authorization); declares (s) assuming responsibility for this declaration, that the inventor (s) is (are): (6) 1, ....... SAC01IE .... Ml.ch.el> . „1.0 .... jDie ._... Ro.s.sin.i, .... Er-5..7.1.2û ..... ROMBAS —-..... FRANGE_______________________________________ .2, ....... CA.CHQ.N ...... Guy., .. „. 3.0_.E.ue.-Jeaii .... Joseph -... Hen.rion · ,. ...... E = .. 5.74.57 — MARL? --------- FRINGE ------------------------ - 3., ...... MS.QJÜEZ ..... Miguel, ...... 1 ..... rue ..... du .- .. p.ré .... .from it ..... lady, ....... SILLYSÜR ..... NIED -...... F-5753G --------------- _______________________________________________________________________________________ XOIIRCELLESrCHAIISSÏ .. — ... 1RANCE_______________________________ claims (nt) for the above patent application the priority of one (s) application (s) of (7) ____________________________________________________ forSYSli ...... dÜflYention ........ filed in (8) ___________________ Exauce_______________________________________________________________________ on (9) ______________ 7 ....... av.riL.19.8.7 ___________________________________________________________________________________________________________________________________ under N ° (10) _____________________ 87 _._ QA9.25 ._______________________________________________________________________________________________________ in the name of (11) _____________________________________________________________________________________________ elect (elect) domicile for him / her and, if designated, for his / her representative, in Luxembourg ------- -------------- ____________LUXEMBOURG___________________________________________________________________________ (12) requestsQnt) the grant of a patent for the invention for the subject described and represented in the abovementioned appendices, with postponement of this grant to ____________________________________________ L --- ---------------------------------------------------------- -------------month. (13)

The depositor / agent: / ______________------------------------------------------- ------------------------------------ (14) 'Π. Deposit Minutes

The above application for a patent for invention has been filed with the Ministry of the Economy and the Middle Classes, Department of Intellectual Property-in Luxembourg, dated: March 23, 1988 .......

; X 'Pr. The Minister of Economy and the Middle Classes, at 1.5.,. Q.Q. hours g ^ p.d.

i? \ -i'i The Head of Intellectual Property, \ v 'A68007_' -, '·· »* __ U \ L EXPLANATIONS RELATING TO THE DEPOSIT FORM.

'(1) if applicable "Application for certificate of addition to the main patent, to the main patent application No ............ of ......... ... ”- (2) enter the surname, first name, profession, address of the applicant, when the applicant is an individual or company name, legal form, address of the head office, when the applicant is a legal person - (3 ) enter the surname, first name, address of the professional representative, industrial property attorney, with special powers, if applicable: "represented by ............ acting as representative "- - (4) date of filing in full - (5) title of invention - (6) enter the names, first names, addresses of the inventors or the indication" (see) separate designation (will follow) ", when the designation is made or will be made in a separate document, or the indication "not to be mentioned", when the inventor signs or signs a non-mention document to be attached to a designation

BL-409 8 / ML

Claim of the priority of the patent application for invention filed in France, April 07, 1987 under the number 87 04925 Descriptive brief filed in support of the patent application for:

THERMO-INDUCTION HOT FLUID GENERATOR

FRANCE TRANSFO Roman Way

F-57210 MAIZIERES LES METZ

THERMO-INDUCTION HOT FLUID GENERATOR.

The present invention relates to an inductive generator of hot fluids in which electrical energy is consumed to produce the heating of any heat transfer fluid, such as water or air, for example.

5 The generators to be considered here are of the “electrical transformer” type comprising a primary winding supplied with electric current by the network and coupled by a magnetic circuit to a secondary winding which has the double characteristic of being tubular and short-circuited The secondary winding is internally traversed 10 by a heat transfer fluid, which heats up in contact with the wall of the tube, itself being brought to temperature by the induced currents which develop there the variable magnetic flux produced in the magnetic circuit by the electric current of the primary winding 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Known inductive generators of this type are described, for example, in documents FR-B-527697 or EP-A-3 0193843.

4

Compared with other known electric heaters 5, these pre-6 thermo-induction generators have, in particular in terms of safety for the user, 7 the advantage of completely dissociating the electric circuit 8 proper (l 'primary winding) of the heating circuit ~ 9 fage represented by the secondary winding.

10

Furthermore, the transformation ratio, specific to 11 electrical transformers, can be used to 12 leave the secondary winding at low voltage while 13 ensuring high power transmitted by the primary, if 14 desired.

15

An essential aspect, not yet fully resolved 16 it seems, remains however the regulation which must make it possible to adjust the heating of the fluid as required.

t '.. · 2

The first document cited above (FR-A-527697) suggests, for this purpose, to use a rheostat placed in series with the secondary winding.

The second document mentioned (EP-A-0193843) proposes a solution 5 more concerned with the energy efficiency of the device consisting in providing the secondary winding with thyristors in cascade pex-putting to vary the number of turns in short circuit, A thyristor per turn acts as an "all or nothing" valve with respect to this turn. 10 The relatively complex assembly thus formed is therefore akin to a multitude of electronically controlled switches, which allow only discrete (non-continuous) regulation of heating by elementary jumps corresponding to the heating power. of a turn of the secondary winding 15.

In this document, reference is also made to an analogous device, known from document GB-A-2105159, in which the regulation is carried out by means of thyristors placed at the primary. Such an embodiment requires that the primary voltage be low enough to be compatible with the load acceptable by the thyristors, which limits the power of these devices.

The object of the present invention is to provide a simple and reliable solution for continuous regulation of the heating, without the disadvantages of the known solutions mentioned above.

To this end, the subject of the invention is a hot fluid generator with thermo-induction of the “electric transformer” type comprising a primary winding intended to be connected to the network and coupled, by a magnetic circuit, to a secondary winding constituted by a tubular coil in short circuit in which circulates a heat transfer fluid to be heated, generator characterized in that primary regulation means of the heating power are provided 35 in the primary which are constituted by a saturable inductor connected in series with the winding primary and by an annoying "rector of direct electrical current - or rectified - controlling said inductance so as to modify the state of its magnetic circuit.

3 'I, * * *.

Advantageously, the saturable magnetic circuit is closed. Advantageously also, the saturable inductor comprises a magnetic circuit comprising three legs, the outer legs each being provided with a power winding, these two windings are mounted in parallel with one another in the primary circuit and the middle leg is provided with '' a control winding connected to the DC generator. The power windings are wound in opposite directions so as to create in the middle leg 10 symmetrical magnetomotor forces which oppose each other at all times.

As will be understood, the regulation according to the invention is based on the following principle: for a given voltage at the terminals of the heating coil, the secondary current is a function of the short-circuit voltage of However, the instantaneous heating power is directly linked to the intensity of the current in the secondary If the voltage across the terminals of the primary winding is varied, the current in the secon is varied in relation " 20 daire and, consequently, the heating power also.

For this, an electromotive force is induced in the primary circuit induced by that of the power source itself, which is opposed to the latter and which is variable so that, for a constant supply voltage , the voltage across the primary winding varies correlatively.

This variable counter-electromotive force is produced by a saturable inductance, the magnetic permeability of the core “at no load” (that is to say in the absence of current at the primary) depends on an applied magnetic field. , created for this purpose by a direct current - or rectified - whose intensity is regulated.

Λ 4 '* t f Thus, the adjustment of the heating power takes place entirely in static, that is to say without any part of the appliance being moved. In addition, the intensity of the direct (or rectified) current intended to control the saturable inductance can advantageously be controlled by a parameter for adjusting the heating, for example the temperature of the water after heating, or that of the room. to be heated, thanks to a regulator to which a set value is given.

The invention will be well understood and other aspects and advantages will appear more clearly in the light of the following description of an embodiment with reference to the plates of attached drawings, in which: - Figure 1 is a representation schematic 15 of a generator according to the invention; - Figure 2 is an enlarged view showing in detail the part of Figure 1 showing the heating control means; - Figure 3 is a diagram illustrating the regrou "20 pement of three generators according to Figure 1 in a single device supplied with three-phase current.

We recognize on FIGFE 1 a conventional structure of electric transformer comprising a primary winding 25 coupled to a secondary winding 2 by a magnetic circuit 3 on which they are both wound.

The primary winding 1, made of copper (or aluminum) is embedded in a mass of epoxy resin 4, according to a provision which is not compulsory here, but typical of transformers "30 mateurs, called" dry ", including the means of cooling by circulation of air have not been shown so as not to "unnecessarily load the figure.

The secondary winding 2 is formed by a tube, preferably metallic, since it is desired to give it good electro- and heat-conducting properties. This tube 2 is connected at its ends to a heating circuit (or more generally to a use circuit) through which a heat-transfer fluid passes, which will be assumed to be water.

5 #

The tube 2 is short-circuited on itself by the electrical connection 5 which connects its two ends. An earthing 6 of the secondary circuit is provided beyond the bridging 5 for safety reasons.

5. The primary winding l is, in turn, connected to the live terminals of an alternating power supply 7 which may advantageously be that of the network.

As can be seen, a saturable inductor 8, controlled by a generator 9 with direct current le, is mounted in series 10 with the winding 1 between points A and B of the pri ~ mayor circuit thus produced. A capacity 19 has advantageously been provided in parallel with the inductor 8 and the primary winding 1 to improve the cos. of the installation. A switch 10 is also provided to allow quick opening of this circuit when necessary.

An exemplary embodiment of the saturable inductor 8 is shown in detail in FIG. 2, to which reference is now made.

This inductance comprises a closed magnetic circuit 11, formed by three parallel legs 12a, 12b, 12c, interconnected at their ends by two rectilinear yokes, respectively upper 13a and lower 13b.

The outer legs 12a and 12b serve as sup "I> ort for electric windings of power 14a and 14b 25 constituting two branches in parallel placed between points A and B of the primary circuit. These windings have the same number of turns and are wound in opposite directions so that the magnetomotor forces they each create in their respective legs are, at the same instant, of equal intensity, but oriented in opposite directions so that their sum is zero in the middle leg for reasons of symmetry.

The middle leg 12c comprises, for its part, a control winding 15 connected to the generator 9 with direct current. 35 It is also provided with a few short-circuit turns 16. These turns make it possible, by a pure self-effect, to avoid the return to the DC generator 9 of the residual alternating magnetic flux resulting from the dissipation of the forces. opposite alternative magnetomotive units in the middle leg when the is not zero.

- · y t. · 6 The direct current winding 15 on the middle leg makes it possible to create a stationary magnetic field which modifies the magnetic state of the outer legs 12a and 12b and, consequently, makes the power current more quickly saturating in one legs in an alternation and more quickly saturating, symmetrically, in the other leg in the following alternation. In order not to harm this greater speed of reaching the saturation threshold of the magnetic circuit 11, the latter is of the "closed" type structure.

10 In this way, when no direct current flows (lc = 0), the inductance effect of the inductor 8 is maximum (“iron inductor”) and, therefore, the effective voltage across the terminals of the husk " elementary 1 is minimal. On the other hand, when the intensity of the direct current is high enough to saturate the magnetic circuit alone, the self effect becomes minimum (“self in air”), and the effective voltage across the terminals of the primary winding 1 therefore becomes maximum Between these two operating limit points, the choice of the intensity of the direct current allows a fine adjustment of the intensity of the current in the primary circuit and therefore of the amplitude of the voltage alternative to the terminals of the primary winding 1.

Reference is now again made to FIG. 1 to complete the description of the operating principle of the thermo-inductive generator according to the invention.

Because the coil 2 of the secondary circuit is short-circuited by construction, an alternating electric current flows there and causes a release of heat · by Joule effect which, essentially, is evacuated by the heat transfer fluid, during from its passage in contact with the internal wall of the coil. This heat release directly depends on the effective intensity of the current in the secondary (of the square of this intensity exactly).

However, this intensity is determined by the voltage 35 induced at the terminals of the coil 2, which depends on the voltage maintained at the terminals of the primary winding 1 and 7 * which we have just seen how it can be regulated by the current. continue it. Thus, the power regulation of the device is obtained by modifying the voltage across the terminals of the primary winding 1 using the saturable inductor 5 controlled by the direct current generator 9.

The regulation can be easily automated, if desired, for example using a regulator 18 controlling the generator 9 so as to keep below a certain desired threshold the temperature difference between a value of con ~ 10 sign Vc and that which it receives from a sensor 17 locating the temperature of the water at the outlet of the secondary winding

Of course, the voltage induced at the terminals of the secondary winding 2 depends on the transformation ratio ”" tion, namely the ratio between the numbers of the coded turns "15 titutive of the heating coil 2 and the in ~ ductive winding 1 respectively. It will therefore be advantageous, in order to obtain high heating powers, to make the device work in step-down voltage by providing a number of turns greater than the primary 1 and by connecting the latter to a power source 7 at high or medium voltage.

It is thus possible to produce heating generators in a very wide range of powers, going from 100 Kw to 10 Mw approximately from a three-phase supply of the medium-voltage network, each phase supplying a heating unit, such as the device illustrated in Figure 1.

Regulation according to the invention is possible between 100% of the nominal power of the device and approximately 10% of this power. Depending on the regulation point, the cos. φ evolves between 0.85 "front" and 0.85 "rear" thanks to 30 the presence of capacities 19.

The metal from which the secondary winding 2 is formed may advantageously be stainless steel, or any other metal having a high resistivity, which makes it possible to work with a low current density (of the order of 35 6 A / mm 2 ). In addition, in the case of stainless steel, the resistance against hot corrosion is entirely satisfactory. The usual dispo ~ sitions are also advantageously taken to improve the heating efficiency, such as the calori ~ fugging of the coil 2 in particular.

t * 8

As for the saturable inductance 8, numerous alternative embodiments, other than that described with reference to FIG. 2, can be retained. However, whatever the structure retained for the saturable magnetic circuit 11, it is important that "it can be saturated by the static field created by the direct current le, when this one is set to its maximum value. We will provide for this purpose a sufficient number of turns for the winding 15, so as not to have to call at intensities that are too high, for example greater than 10 A.

Likewise, due to the fact that the direct adjustment current has the effect of modifying, on the magnetization curve giving the magnetic induction as a function of the field, the position in height of the saturation level as well as 15 l location of the start of this bearing on the abscissa axis, it may be advantageous to size the magnetic circuit 11 so that, for a given nominal power available in the primary, we are already in the vicinity of the beginning of the bearing le = 0.

20 Beyond this, the circuit would be undersized, because a fraction of the alternating magnetic field created by the coils 14a and 14b would propagate in the air and we would then lose the width of the regulation range of the trans power "set secondary, range which can go (as already indicated) 25 from 10% to 100% of the nominal power of the device. Below this the circuit would be oversized, which, in itself, would be a factor of additional cost which, in moreover, contributes to tightening this time the range 10-100%, and therefore imposes a more difficult precise adjustment of the power in this range.

30 One could, of course, achieve a similar result by adapting to a circuit 11 of given size the number of ampere-turns of, or the windings 12a, 12b.

The invention is entirely usable with a usual three-phase supply from the medium or high voltage network for the distribution of electricity. In this case, the ap ~ similar shown in Figure 1 becomes a unit of a more complex assembly which contains three.

* 9

Such an assembly is shown electrically in FIG. 3. Each phase, denoted U, V, W, of the medium voltage network at 20,000 volts between phases, supplies, via a saturable inductor 8, 8 ′, 8 ", a winding primary 1, l ', l ".

5 These three windings are mounted here in a star and each of them induced, by means of a magnetic circuit not shown, in a secondary short-circuit winding constituted by the coil 2, 2 ', 2 ". Each coil is mounted on a branch of a hydraulic heating circuit 10 which contains three in parallel. More generally, this type of device can be multi-phase and therefore include a number of elementary heating units, in accordance with the thermo-inductive generator described, equal to the number of phases of the supply 1 2 3 4 5 6 7 8 9 10 11 It goes without saying that the invention cannot be limited 2 to the exemplary embodiments which come from 'be described, but 3 extends to multiple variants or equivalents, to the extent that the characteristics set out in 5 the claims below are met.

6

It will be noted that the field of application of the invention "7 tion includes the manufacture of hot water for heating 8 buildings, or integration with industrial processes. From 9 meme, the invention applies to heating of fluids calo ~ 10 carriers other than water, for example oil or even 11 of sulfur or liquid sodium, intended to be used as such, or to generate high temperature steam in exchangers.

Claims (8)

10 * 1. Hot fluid generator with thermo-induction of the “electric transformer” type, comprising a primary winding (1) intended to be connected to the electricity distribution network (7) and being coupled, by a magnetic circuit ~ 5 ticks (3), to a secondary winding (2) constituted by a tubular coil in short circuit (5) in which circulates a heat transfer fluid to be heated, generator characterized in that primary heat regulation means are provided , which 10 consist of a saturable inductor (8,11) connected in series with the primary winding and by a generator (9) of direct current - or rectified - controlling said inductor so as to modify the magnetic state of its circuit saturable magnetic (11) 15 2. Hot fluid generator according to claim 1, characterized in that the saturable magnetic circuit (11) is a closed circuit. 3. Generator of hot fluid as claimed ~ tion 1 or 2, characterized in that the saturable magnetic circuit 20 (11) comprises three legs (12a, 12b, 12c), in that the outer legs (12a, 12b) have each a power winding (14a, 14b), these windings being mounted in parallel in the electrical circuit connecting the primary winding (1) to the network (7), in that the middle leg (12c) comprises a control winding (15) connected to the direct current generator - or rectified - (9), and in that said power windings are wound in opposite directions so that the alternating magnetic fluxes they create in the saturable magnetic circuit (11) oppose 30 at all times in the middle leg (12c). * V * 9 11 4. Generator of hot fluid according to CLAIMS "tion 3 characterized in that the middle leg (12c) also has eourt-eircuit turns (16). 5. Hot fluid generator according to claims "5 tion 1, characterized in that it is equipped with means (17,18) for automatic regulation of the heating power. 6. Generator of hot fluid according to the claims "/ · tion 1, characterized in that the tubular coil (2) is made of stainless steel. 10 7. Hot fluid generator according to claim 1, characterized in that a capacity (19) is mounted in parallel on the primary circuit. 8. Polyphase electric heating device consisting of as many elementary heating units as there are phases of the electrical supply to which it is intended to be connected, each elementary heating unit conforming to the hot-induction thermo-fluid generator according to claim 1.