DE6901693U - HEAT EXCHANGER - Google Patents

Description

Registration date: Stuttgart, January 7, 1969

Haytheon Company P1909 S / kg

iöxington, Mass., V.St.A.

Heat exchanger

The invention relates to a heat exchanger L.

ι »for two flowing media with one between the two {Γ

Media arranged thermally conductive separating layer and I one provided on one side of the separation layer - Ig

Passage for the one medium « m

The effective transfer of heat as well as the effective |

and economic exchange of thermal energy between \

flowing media, one of which is to be heated or i

is to cool down is very important for today's technology *

t »
ir

The areas of interest are, for example, in the household with cooking and heating and in industry with numerous industrial processes such as condensation, distillation and heating. With the technology of heat exchange is the complete transfer of thermal energy from a heated flowing medium to one other medium the most important parameter. For example, with normal burners that have limited heat- _ Transition surface have the exhaust gas temperature some

\ £> a hundred degrees, suggesting that a considerable

The amount of thermal energy contained in the fuel is not used and is discharged with the flue gases Therefore, with today's heat exchange devices, efficiencies between $ 0 and 60? S are common

An increase in the transfer area between the hot and the medium to be heated with the help of baffles, plates and other obstacles

, was with the known arrangements

not accompanied by success with regard to an improvement in the efficiency of heat transfer An expression,

Q which is often used in technology to

To describe transmission properties is the "power density ¹¹ , which indicates the heat energy which flows per unit of time through a unit of area of a body to be heated observed · This dating shows that high with the help of numerous "sources available thermal energy, such as: - for example, a direct j lasae, the ability to?

♦ /.

690169a

has to deliver a heat output of 7 kW, higher efficiencies can be achieved if the Power density of the transmission structure in a suitable Way can be improved.

The invention is based on the object of a heat exchanger to create, in which much higher power densities are possible, and which is therefore through is characterized by a significantly better degree of efficiency. This object is achieved according to the invention by that in the passage for one Meölua there is a tiel count thermally conductive body is arranged, which form an optically dense grid matrix in the passage and their average size is substantially equal to the maximum that the optical diameter in the la. essential causes the shortest dimension along the passage and one or more paths for the? lm of the corresponding Medium through the grid matrix "

The heat exchanger according to the invention thus has a compact structure for rapid transfer of thermal energy to it and it is made possible by the arrangement of a A large number of thermally conductive bodies in a connected »porous lattice matrix represents a significant increase the power density achieved · In fact, power densities can be achieved by the arrangement according to the invention that are 10 to 100 times the power density in the previously known heat exchangers is achieved.

In the heat exchanger according to the invention, the spaces between the adjacent surfaces of the bodies of the matrix form a winding path for a flowing heating or cooling medium. The heat-conducting separating layer adjoining the lattice matrix enables the flow of a second medium which has a higher or lower temperature than the medium flowing through the lattice matrix. The porosity and density of the lattice matrix, which is composed of individual heat-conducting bodies, is nothing ZosstruktioBparaiieterj der su the effective heat exchange between the media leads »According to the invention, an optimal promotion for the depth and the porosity of the grid matrix is that * that the average size of the thermally conductive body is essentially equal to the size ₄ that an optically dense path is essentially in the shortest distance along a passage / for a flowing medium results · For the purpose of describing the invention, the expression "optically tight ¹ · in relation to the packing of the individual heat-conducting bodies , is defined in such a way that a light beam _i the

'is aimed at the resulting structure, not

is directly visible, but that traces of light are noticed in the spaces between the individual bodies which can be traced back to internal reflections and light scattering. The heat transfer— matrix can be produced by turning the thermally conductive body by conventional hard or soft soldering, Sintering or coating of the individual bodies with substances that are suitable for such metallogical processes are to be put together.

"or a narrow path

■ κ ce ·

Sin another term necessary for the understanding of the invention "and the description of the parameters of the individual Tssr Governing Body and the way of the ! maximum heat flow is useful is that "characteristic dimension". This term is intended to mean the distance between "adjacent thermally conductive." Designate separation layers of a Durciilasse that of the optically dense grid matrix is filled and through which one of the media flows. In a circle-

w ith arrangement, "in which the matrix is inside,

"is located is the characteristic dimension of the Diameter of the banal * of the flowing medium contains * for flat or level arrangements * the Im Distance from one another, parallel, thermally conductive separating layers have, between which the grids matrix "is located," the term denotes the distance between de ^. parallel separating layers for arrangements * the lines embedded in an outer grid matrix for a medium, this expression is intended to mean the distance between adjacent 2 separating layers of the lines denote «If circular lines are used,

ji. then can the characteristic dimension through HittoLung

the distances can be determined at certain points

Several exemplary embodiments are described below with reference to the drawing of the invention, including one embedded in an optically dense grating matrix, helical snake * Such an arrangement makes an effective source of hot water for the home

fAHQ

· E. e «e

· · Es · β

• ·

-and can be used advantageously at any desired consumption

place to be attached · Another embodiment

§ the invention makes the arrangement more thermally conductive

"Body both within a medium line as well outside of this line use to establish thermal power densities absorb up to 1500 W / cm, like it for example - for the boiler of combustion systems is of interest «The efficiency that can be achieved with the invention has a significant reduction in space requirements and costs € 1) for the heat exchanger 2ur? olge ·

Further details and refinements of the invention can be found in the following description »In ά & ΐ: the invention is described and explained in more detail with the aid of the exemplary embodiments shown in the drawing can be applied to several in any combination It shows:

Pig * 1 shows a vertical cross section through one embodiment of the invention for heating a flowing liquid with the help of a outer matrix arrangement,

FIG. 2 shows the detail 2-2 of the arrangement according to FIG. 1 on an enlarged scale,

Fig. 3 is a section along the line 3-3 through the Arrangement according to Fig. 1,

V ä * i \

0 y υ10 y

C ( m <κ mm mm

Fig. 4 is a schematic representation for illustration the main parameters of the invention Matrix,

5 shows a schematic representation of a heat exchanger with flat surfaces _t

6 shows a schematic representation of the embedding of medium lines in an outer matrix »

Fig. 7 is a schematic representation of a complete system that incorporates the arrangement of the
Fig. 1 to 5 contains,

8 shows a vertical section through a further embodiment the invention,

Fig. 9 a horizontal section through the embodiment of Fig. 8 taken along line 9-9 ₅

Fig, 10 is a vertical section through a further training Γ> guide die of the invention for a very

high power density is set up,

11 is a vertical section along the line 11-11
by the arrangement according to FIG. 10 and

12 shows a partial section through a further embodiment the invention.

8901693

-S-

the preferred Äusrührungsbeispiel according to FIGS. 1 to 5 is described in detail, it is appropriate to explain the principle of the invention with reference to FIGS. 4 to 6. Figure 4 illustrates a heat transfer arrangement which has a high rate of heat transfer and which makes use of a structure that allows for optimum power density along the path of the heat flow. In this structure, thermally conductive bodies are metallurgically connected to one another on adjacent surfaces and form an optically dense barrier matrix along the length of the medium flow. The spaces between the bodies define a tortuous degree of heat transfer.In the drawing, spherical bodies such as shot or bearing balls are shown, although similar results can also be achieved with other, similarly arranged bodies, the shape and dimensions of which meet the requirements of the invention. Suitable thermally conductive materials are, for example, copper, brass, stainless steel, carbon steel and aluminum, as well as plastics in which metal particles are embedded. Iron or copper-containing particles can be coated with a eutectic copper-silver solder and the entire matrix arrangement can be connected to form a conglomerate by a known method, for example by soldering, sintering or welding. For conductive bodies consisting of Αΐτπτηττίητη with an iüauchlöttechnik are used.

One of the design features »that of the application of the invention "must be observed is compliance with the mean liaximal size for the body particles, so that one optically dense matrix with the shortest possible length in the direction the medium flow is achieved. A medium flowing along the path indicated by arrow 13 hits onto the optically dense structure which is connected to a surface of a conductive separating layer 12. By the attachment of a number of body particles 10 arranged to be optically dense in the Grid matrix forming a tortuous heat transfer path increases the overall efficiency of the heat exchanger improved. The path of the flow of thermal energy from the medium flowing through the matrix 11 and the surface the separating layer 12 is indicated by an arrow 14 and results in heat transfer to the medium, that contacts the opposite surface 15 of the release layer 12.

Another requirement for an effective arrangement for heat transfer along the shortest possible lengthways of the amount of heat flow relates to the number of times

or branches
bonding points / in each direction from the point of thermal contact along the thermal path to the closest conductive separating layer. In FIG. 5, a matrix arrangement 16 is provided between the surfaces of separating layers 17 and 18 which are arranged at a distance from one another. Such areas can arise, for example, between the walls within a pipe or between the outer walls of pipes arranged at a distance from one another. The path of the medium flow is through

- 10 -

an arrow 19 indicated. It was found that optically dense arrangements achieve optimum results when the connections are adjacent to one another Areas in a desired direction of the thermal path on the order of two such connections lies · The matrix structure shown in 'J-'ig · 5 is an internal arrangement and can be in circular or rectangular conduits as well as between flat, level plates can be used.

The “remaining requirement” defined above is the characteristic dimension represented in FIG. 5 by the Arrow GD c ^ ls the distance between the parallel interfaces 17 and 18 are indicated. For the highest warmth— The transition rate in the case of an optically dense grating matrix can be the heat path to the next interfaces for a flowing medium directed along the path 19 by the perpendicular arrows 20 and illustrated. The maximum length of the heat path through the matrix from one medium to the next The interface is then half of the characteristic Dimension of the arrangement. For lattice arrangements [which make use of discrete bodies, the

yy. :. 3 medium size of the. Body preferably about

a third of the characteristic dimension of the

- I ₁ order. Bodies with much larger [dimensions, for example with more than half

[the characteristic dimension, were not together

form a sufficiently optically dense arrangement. such an arrangement for the upper trans-

f supply of additional amounts of thermal energy ineffective,

f At the other end of the area hurt theraisc &

conductive body, their diameter

€ I Ii I t

C * · ItI »ft · *

is smaller than one sixth of the characteristic dimension "the requirement" with regard to the A-ny-ani , the connection points and thereby reduces the effectiveness of the thermal conductivity of the device for heat transfer.

Pig. 6 illustrates an embodiment of the invention in which lines for a flowing medium, which are arranged at a distance from one another, are embedded in a grid matrix xuid a second flowing medium aizf the area, a ^ rischsn dsn. Lines is specified ^ as indicated by the part 22 · This structure is referred to as an external type and there are also. "Here again the design criteria referring to the A-ngani of the connection points and the optical density of the matrix can be used« Bine line 23 with circular cross-section j which may consist of an a-ngafoi rectilinear parallel portions, or a helical coil, conductive bodies is in the G-itter matrix 24 of thermally embedded _t after, the invention is constructed. the characteristic dimension of this structure is between calculated from the wall surfaces of the line and is derived by taking the mean value from dimension A and dimension B, which indicates the greatest distance between the lines are · As in the example shown in Pig »5 is again the maximum of the W ärmepfades preferably equal to half the characteristic dimension

6Α

■ e- »e -> it e »

- 12 -

or half the mean distance between the in Line walls arranged at a distance from one another. That of the soldered connection points, from the point of impact counted out is of the order of size or two, and it is the mean size of the bodies between half and one sixth of the characteristic dimension at the required density.

The high heat transfer rate or the increased J-eistungs- density, which is achieved by the invention, Va-np well dex ^ large number of surfaces to be attributed to the matrix is formed from the conductive region of each of the corpuscles "The flowing medium, therefore kozamt with a larger "heat-absorbing surface in contact than would be possible without the winding"! heat transfer path through the grid matrix arrangement according to the invention Square centimeters of the area of the body to be heated and per unit of time can be · When compared with known arrangements, ■ in which only power densities of about 15 watts per square centimeter and per unit of time can be achieved, it becomes clear that an improvement of several orders of magnitude is possible with the invention · One to determine the design criteria for ei An equation useful according to the invention is the following:

(Temperature drop) (thermal conductivity (1) thermal path L = of the material;

Heat flow

The term "heat flow" refers to the heat energy supplied and can be expressed in kilocalories per hour and

• · · · ■ * ci

C · ■ S

- 13 -

Square centimeters of the surface of the separating layer through which the "heat is to be transferred. The" thermal conductivity of the material is a constant that can easily be taken from corresponding tables. when the temperature gradient has a unit value. As indicated above, the thermal path then gives half of the characteristic dimension of the arrangement. The dimensions <L & v body particles of the matrix can then easily be calculated according to this who * of the characteristic prostitutes. = Sion * The application of this equation is demonstrated in the following with reference to one of the exemplary embodiments described,

Zn the Pig. 1-3, there is illustrated a highly effective form of practice of the invention which will now be discussed. The helical snake 30 is embedded in an internally disposed sintered mesh matrix 31 so that the matrix surrounds the snake. The iäatrix 3Ί consists of individual therEJiscl- conductive bodies ^ s the geaaß the teachings of the Srfindung as

. Wordisa is explained above, the desired optical appearance j cause density · the thermal conductivity, the

permissible pressure drop and determine the power density the pitch, diameter and total length of the Snake »from which the naxisially admissible Vräaeweg is derived results. This again is characteristic

Dimension determined. The demands for training the matrix will then be of the characteristic value

ß UfH

- 14 -

I dimension derived; · Sin ~ sH-m: =? A 52 and an outlet

j of the snake 31 are seat of the water source or one

I Device for using the liquid medium

1 tied · Embedding the snake in the grid matrix

1 can be done by pulling the helical snake 30

I is inserted into a cylindrical outlet that is made of

j two concentrically arranged, tubular 3-shaped parts

I is limited from a material »that you don't ax

S - ^ connects the parts of the body, the dimensions of which become dea

I W value of the characteristic dimension in relation

I st @ h £ n · The ^ oxsrteile ^ abea. vex-aeiixedeiieiSicciiAesser

I and it can de? annular construction between this. Pora

I share with the individual Xoxper parts rolled out

I will shake, shake and vibrate the whole

I order can be, the desired distribution of the Xfields

f around the coils of the snake achieve * you Gesast—

I arrangement will then be at the required temperature

? metallogically, treated and then the?

I removed · those from the outer grid and the

I serpentine ^ esant structure is then in the

I 'illustrated embodiment of the invention assembled

ί and it becomes a central one of the heat transfer matrix

Combustion kaiamer 38 defined

Typically, a burner plate 3 ^ - can be provided

I will have a plurality of channels 35 to the inlet of a

I air gas mixture under pressure in the combustion chamber

", 38, which is connected by a line 36 and the

I pitting 37 connected source is supplied ·. In the

ι ßrennerplatte 34- is laterally and at an angle eiae J & ünd—

ι device 4-0 of known construction arranged, with-

\ f ν \ f I Kf if

For example, a spark gap that provides the required Causes ignition of the gaseous fuel mixture. An outer wall 41 surrounds the arrangement serving for heat transfer and a smoke pipe 42 for it leads the exhaust gases to a normal chimney, not shown in detail. A cover plate 43 is with the assembly for heat transfer and conduction, for example with the help of nuts and bolts, which are partially embedded in the matrix.

A practical embodiment of a Y / arm transfer unit, as it has been described with reference to FIGS to generate l / m. The burner for heat transfer unit as well as all electrical control devices, including a thermostat, an air filter and safety devices have been combined to form a device that .of a height of about 15 cm, a width of about 27 _S 5 cm and a total length of about 45 cm up pointed. Such a heat transfer module can replace conventional hot water heaters of the storage type as are common today and have diameters of about 60 cm and heights of about 180 cm. The new improved device can be conveniently mounted near the point of consumption. In view of the extremely low cost, many such devices can also be built in, resulting in significant cost savings in terms of installation, such as are incurred in today's centralized domestic hot water systems «

In the Asorunimg mica Fig y., The embodiment of the invention is according to the Fig. 1 Ms 3, including the associated components, in their entirety as V / äraeübertragungsnodul 50 denotes. A blower 51 is connected by means of the fitting 37 and conveys the air and gas mixture in the combustion chamber 38 "from a source 53 'of each commercial urban, Erdoder can provide bottled gas, the gas is a magnet teuerven-sii * & ■ and a regulator 55 led to the inlet Ks of the fan 51. Sufficient for most purposes

a fan of small dimensions and cheaper design. The flue 42 protruding laterally from the new transfer module 5Q enables the combustion gases to escape to a conventional outlet. In contrast to the effectiveness of the heat transfer and the fact that the flue gas temperature is extremely low, a small outlet opening in a wall, such as is used for household tumble dryers, is sufficient . There is no need for a chimney with a natural draft, which also results in savings in construction costs. The water supply is indicated by the reference number 5 *> and the heated water is fed through line 57 to a tap 58 for immediate use. A safety valve 59 responsive to temperature and pressure can be arranged in line 57. It follows that large storage tanks or boilers, as they are used today as Warisa water sources, can be completely avoided. Instead, a compact and unitary source has been disclosed which can easily be installed immediately where it is needed, for example in the bathroom or in the kitchen.

.A

The associated circuit for controlling the fan as well as the thermostat and ignition monitoring together with the solenoid valve for the gas source were not specifically described because they are commercially available Components and the installation of these gowns takes place according to the known technology.

In the embodiment according to the Pig. 8 and 9 is ejjae Group of straight bores 61 in its grid matrix 62

($ Embedded, which consists of thermally conductive bodies,

as described above. An upper end plate 63 is provided with a medium inlet 64 and is fastened by means of nuts 65 to screws 66 which are let into a ring 67. The optically dense matrix 62 surrounds the straight tubes 61 which are embedded therein · The ends of these tubes and the inlet 64 · stand with a channel 68 on the inside of the ring 6? in connection. A similar arrangement is on the opposite. set end of the matrix and includes a lower end plate 71 and an adjacent ring 70? which is provided with an inner channel 68a into which the ends of the tubes 61 open. A medium outlet 72 is attached to the lower ring 70. The lower end plate 71 further has a number of channels 73 for a gas-air G ^OT aisch, which in the assembly through. .ν - '* "ν,: a conduit 74- is inserted. The ignition of the fuel -.-' - 'material within the chamber 75 is effected by a spark plug 76 which is carried by the upper end plate 63.

The embodiment according to FIGS. 10 and 11 is intended for applications with very high power densities.

6901698

In this embodiment the lines are 77 and 78 concentric, arranged about a common axis. The outer line 77 is closed at both ends by conductive plates 79 and 80 "Ein Inlet 81 allows a liquid medium to enter, while an outlet 82 allows the . Medium in heated or vaporous state allows. The inner conduit 78 is at its ends

"OffSE, SO cLcuj SjLZL 5Χϊτ £ ϋ2ΐοβ5 MedJLtZiü, like example—

wise the gases of a direct. Oxygen gas flame, can flow through the interior of this tube »

The direction of romanization is indicated by arrow 84. An optically dense matrix arrangement 85 consists of a large number of thermally conductive spherical ones Bodies that are connected to one another according to the I teach the invention the heat transfer path

I make up. The matrix assembly 85 takes the main part

I of the cross section of the line 78 and it is the

% characteristic dimension of this link equal

I of the inner diameter of the circular conveyor. Management,

| l 'as it is by, the arrow 86 and the designation CD an-I is interpreted

A lattice matrix 87 of the same type fills the cross-section

I of the external line 77. Since the inner Gittenaatrix

ρ 85 acid a rope the total length of the interior

I. occupies for the concentration of the hot medium,

The heat transfer area between the

S media in the. corresponding lines essentially

! j in the construction indicated by bracket 88. This

I structure, enables use at very high power

I poetry.

f -Λ

An example of the application of the above equation (1) "in the transfer of heat from an intense heat source is given for the design of FIGS. 10 and 11. Using a direct flame, it is assumed that in the flaina - Xlacke a Leistuzxgsdielite of about I5OO W / ce is achieved ι »^ trotsdes sit silver ^ τ _ copper particles can be used It is also assumed that the Temperaturabfall- should be 55 ° C, copper has a thermal conductivity of about..?. 3 kcal / h, cm. ⁰ C * In the final structure, however, only a lower conductivity is achieved due to the soldered joints and the optical density of the heat paths the length of the heat path L is calculated as follows:

55 ° C χ 1.5 kcal / h.cm. ° C '

L = * = 0.635 cm

130 kcal / h.cm

The characteristic dimension is twice the length of the heat path and is therefore 1.27 cm. A thermally conductive body with a mean size of around 2 - 6 mm is therefore required to optimally to achieve optical density. For most applications, the thermally conductive body size becomes 1/3 the characteristic dimension, i.e. here a size of 4 = mn, is preferred.

- 20 -

In the further embodiment of the invention shown in Pig * 12, a helical snake with a plurality of turns 90 is embedded in an outer matrix 9 "i. If the correct design values have been chosen for the matrix bodies surrounding the snake ? be filled eilcxien the inside of the snake with other conductive 5, which do not need to meet the same critical requirements. 3) in greater detail can in steam generators or capacitors particles -they braids * wires, chips, chips and flggglftl CHFM zrRTm e> n && itz w & Da & TLf ~ & ί. & they are indicated at 92 »Bine such a structure for filling out the pipe is of particular importance for the industrial application of the invention *

The representational models have the advantages of Zoapaktheit and Uirksaakeit shown that disclosed WärmeübertragungsanoiidEung that lie in the fact that the optically liatrixstruktur density significantly increased power densities allows "You Sonstruktionskriterien regarding the Arigafoi the Verbindtsngsstellen along the heat path, and the average size of the thermally conductive body in bszug on the characteristic dimension for achieving the desired optical density has been dealt with in detail; The above discussion and exemplary application of the equation facilitates the application of the invention in practice. In addition to the exemplary embodiments, numerous other designs can be thought of for other purposes. For example, the theraisch conductive bodies that are in the

: ι - to be.

From: fii ^ -rungscebeispielen according to Figo 1 and 8 with; the outer wall surfaces of the ear are in contact, omitted "? e2? the _s so that this constriction of the longitudinal walls forming the Treimsch ± oh-t free £ rc. The secondary transfer path within the matrix between the lines, which are generally arranged at a distance, is pathways of the current of ideas

s2i all dem

AüsfüiLrungsbeispiele described ζσοσ to Erläu- -fcerung the STiindung serve j without the Sr £ indung ia any limiting a manner xmß. that deviations from these exemplary embodiments are possible without departing from the scope of the invention *

691) 1693

Claims (1)

• ttil - 22 - Payment claims 1. Heat exchanger for two flowing media with a thermal barrier layer arranged on the two media and one on top of one Side of the iDrennschicht provided passage for the one medium, characterized in that in this passage a plurality of heat-conducting body (10) is arranged in the passage a Form £ 1 ^f optically dense grid matrix (11) and their <iu? eii3eii2i / & süelie GröSs? ^ a substantially equal to the maxiisus is "which effects the optical density in the substantially shortest dimension along the passage and forms one or more space for the flow of the corresponding hedium through the lattice matrix (11) * 2 * War.asaustauscher according to claim 1, dadujpch characterized, that the body (10) "conducts each other and preferably also ax of the srena class (12) are connected. 5 · Heat exchanger according to claims 1 and 2, characterized characterized in that the bodies (10) with each other and optionally with the separation layer (12) are metallogically connected " 4. Heat exchanger according to one of the preceding claims, characterized in that the average number of junctions between adjoining surfaces along the transition path in the direction (14) in which the next 1693 - 23 - reached surface of the separating layer (12) is on the order of two 5. Heat exchanger according to one of the preceding claims, characterized in that the separating layer forms a wall structure (17 * 18) delimiting the passage for the medium and the average size of the heat-conducting bodies (16) is about half to one sixth and preferably about one Third of the characteristic, ^ dimension (CD) of the wall structure is 6 * Heat exchanger according to one of the preceding * claims, characterized in that the partition wall is formed by the wall of a line (23) for one of the media and the heat-conducting bodies (24) are arranged on the outside of the line (23) and form a winding path on which the second medium can flow through the optically dense grating matrix (24) 7 · Heat exchanger according to claim 6, characterized in that shows that the line (30; 61) has several turns or several parallel sections and the with the outside of the line ($ 0; 61) connected grid matrix (31 or · 62) one or more paths for the flow of the second medium between the spaced turns or line sections through it. • Λ so ι 8. Warmth from fans rather according to claims 6 and 7. characterized in that the grid matrix (31; 62) forms a cylindrical hollow body with a central passage (38 or 75). 9 * Heat exchanger according to one of the preceding claims, characterized in that the partition formed by the wall of a conduit (78) for one of the media; becomes and the optically dense matrix (85) substantially fills the inner cross section of the line (78). 10. Heat exchanger according to claim% characterized / characterized, that concentric to the line (78) one second line (77) is arranged, with which the other medium on a path in the immediate vicinity the outer wall surface of the first line (78) to be led. 11. Heat exchanger according to claims 9 ^ n- 10, characterized characterized in that a grid matrix (87) is arranged in the second line (77) which is im has essentially the same structure as the matrix (85) in the first line (78) 12. water heater with a heat exchanger according to claim 8, characterized in that it has a Means for heating the second medium in the passage (38). Instantaneous heater according to claim Ί2, characterized in that the device j from Srv / ärnen of the second medium to a burner (57, 35) which is indexed with the fuel in the passage (3β). Instantaneous water heater according to claims 12 and dadtirch g ^ indicates that the device for. Heating the second medium has a fan (5Ό. 15 · Instantaneous water heater according to one of the claims i2 to 14, characterized in that the device aaass Heating the second medium comprises an ignition device (40). 16. Water heater according to one of claims 12 to, characterized in that one end of the passage (38) is locked I ?. Flow heater according to one of claims 12 to characterized in that in the line (90) one Variety of thermally conductive body (92) is included. 690169a