WO2018182417A1

WO2018182417A1 - Heat exchanger

Info

Publication number: WO2018182417A1
Application number: PCT/NL2018/050200
Authority: WO
Inventors: Wilhelmus Josephus Maria SCHOTTMAN
Original assignee: Schottman Wilhelmus Josephus Maria
Priority date: 2017-03-29
Filing date: 2018-03-29
Publication date: 2018-10-04
Also published as: NL2018604B1; EP3601897A1

Abstract

The invention relates to a heat exchanger, comprising: - a closed reservoir filled with a first medium; - at least one channel which is arranged in the reservoir and through which a second medium flows from an inlet to an outlet; - at least one light source arranged in the first medium in the reservoir, such as a spiral lamp; and - reflection means, comprising a layer such as a mirror or metal layer, arranged on at least one of the inner wall of the reservoir and an at least one partition arranged in the first medium.

Description

Heat exchanger

The invention relates to a heat exchanger.

There is a traditional reliance on gas, in particular natural gas, for heating spaces. Carbon dioxide is released during the combustion of natural gas, this being associated with damage to the environment, in particular climate change. The extraction of natural gas is also

associated with damage, in particular subsidence. Alternatives for heating are for this reason being sought.

An example of such an alternative is described in the Netherlands patent NL 2011831. This describes a device with a circuit carrying cooling agent, used for instance in supermarket refrigeration, and a circuit carrying heating agent, used for instance to heat the same supermarket, wherein both circuits are in heat-exchanging contact so as to thus produce energy savings.

Such a system produces savings in the quantity of natural gas required, although a significant dependence on natural gas still remains here.

The object of the invention is to reduce or even obviate the above stated problems.

This object is achieved using a heat exchanger, comprising :

- a closed reservoir filled with a first medium;

- at least one channel which is arranged in the reservoir and through which a second medium flows from an inlet to an outlet;

- at least one light source arranged in the first medium in the reservoir, such as a spiral lamp; and

- reflection means, comprising a layer such as a mirror or metal layer, arranged on at least one of the inner wall of the reservoir and an at least one partition arranged in the first medium.

Light and heat are generated with the light source in the heat exchanger according to the invention. The resulting energy is transferred via the first medium to the channel which is in heat-exchanging contact with the first medium and to the second medium which flows therethrough and is separated from the first medium and which hereby heats up. The energy from the light source is reflected, and possibly as it were magnified, by providing reflection means.

The reflection means can consist of a layer arranged on the inner wall of the reservoir and/or one or more partitions optionally placed in the first medium, although this inner wall or optional partitions can also consist wholly of these materials. A metal layer is particularly also

understood to mean a silver foil or an alloy such as stainless steel. The partitions are preferably provided with the layer on both sides so that reflection means are present in both of the compartments separated by the partition. It is preferable that the partitions are wholly covered with the layer in order to maximize efficiency.

The use of a spiral lamp as light source has had favourable results, in particular an 800-Watt spiral lamp. When one or more partitions are provided, at least one such light source is then preferably received in each compartment created by these partitions. The lamps preferably have a core temperature of at least 400 degrees Celsius for sufficient heat transfer. The lamps preferably have a heat-up time of 3 seconds or less in order to be able to ensure a sufficiently rapid activation. It has been found that placing at least three such lamps produces a sufficient supply of heat for most applications .

For good heat transfer the wall of the channel is preferably made of a material suitable for the purpose and preferably a suitable metal, such as for instance copper.

The first medium can be or comprise for

instance air or water. The second medium comprises and is preferably composed substantially of water.

The heat exchanger can be connected via the outlet to a device demanding heat, such as for instance a radiator, in which (a part of) the heat transferred to the second medium in the heat exchanger is consumed. Should heat still remain after passage through the device demanding heat (for instance because the second medium is still hotter than 120 degrees Celsius), a device which converts this heat to energy, such as for instance a turbine, can then be placed further downstream of the device demanding heat.

The heat exchanger according to the invention is used particularly advantageously with the device from NL 2011831 as described above, wherein the heat exchanger

according to the invention can be arranged for instance in the circuit carrying heating agent, or can replace this circuit.

The heat exchanger preferably also comprises at least one of a pressure gauge and a protection against

overheating, which ensures deactivation of the heat exchanger when it is determined using a thermometer that a preset temperature has been reached, for instance in the second medium.

It is possible that one channel is arranged in the reservoir, although there is the possibility of

accommodating a plurality of channels in parallel in the reservoir. In the case of for instance two channels it is preferred here to use a first channel with a large contact surface area connected to a heat-demanding device with a relatively high heat requirement, together with a second channel with a smaller contact surface area connected to a heat-demanding device with a lower heat requirement, in order to hereby distribute the heat produced as required. The second channel can for instance be connected from the outlet to a device for heating tap water.

In a first preferred embodiment of the heat exchanger according to the invention the heat exchanger comprises an elongate element arranged in the first medium, wherein the at least one partition extends between the inner wall of the reservoir and the elongate element for the purpose of dividing the reservoir into a number of compartments.

The elongate element is arranged in the first medium and the partitions extend between the elongate element and the inner wall of the reservoir and are preferably

attached to the elongate element and/or the inner wall. The reservoir is hereby subdivided into compartments or preferably separate chambers. The channel preferably runs through each of these compartments and a light source is arranged in

preferably every compartment in order to increase the

efficiency.

The elongate element and the partitions are preferably arranged in the reservoir such that compartments of substantially the same volume are created.

When a plurality of channels extend through the reservoir, wherein this plurality of channels each comprise an elongate part, these elongate parts then preferably run parallel and lie against each other in order to give the channels a compact form without obstructing the lamps.

In a second preferred embodiment of the heat exchanger according to the invention the channel comprises an elongate tube which extends through the first medium.

An elongate tube is inexpensive to produce and requires few specific operations and can be used to connect another part of the channel to or in the direction toward the inlet or outlet.

In a third preferred embodiment of the heat exchanger according to the invention the elongate element is the elongate tube.

The number of elements in the first medium is reduced when the elongate element is the elongate tube. This reduces the production costs of the heat exchanger and can moreover improve the heat transfer to the second medium as compared to a situation in which the elongate element is not the elongate tube, in which case a situation could occur where heat is lost via the elongate element.

In a fourth preferred embodiment of the heat exchanger according to the invention the channel comprises a spiral-shaped part with a number of turns extending one above another.

The use of a spiral-shaped or, in other words, helical part has the advantage that a large area of the channel within the reservoir is in heat-exchanging contact with the first medium, and that the efficiency is therefore increased, while a spiral-shaped part moreover has an

organized and regular structure whereby maintenance such as cleaning is easier. In addition to a spiral with round turns, a spiral is also understood to mean a spiral with other types of turn (for instance polygonal turns) .

When a plurality of channels are arranged in the reservoir, the spiral connected to the heat-demanding device with the lowest consumption then preferably has a smaller radius than the spiral connected to the heat-demanding device with a higher consumption, in order to thus distribute the available heat in uniform manner according to consumption.

In a fifth preferred embodiment of the heat exchanger according to the invention the turns are pressed onto each other and preferably attached to each other with adhering means such as tin solder.

The quantity of second medium in the reservoir is increased by pressing the mutually overlying turns onto each other, this increasing the heat transfer. Adhering these turns to each other with adhering means such as tin solder ensures that the turns remain in this configuration, this enhancing the operational continuity of the heat exchanger.

In a sixth preferred embodiment of the heat exchanger according to the invention the spiral-shaped part extends along the inner wall of the reservoir.

When the spiral-shaped part extends along the inner wall of the reservoir, or more particularly when the centre of the turns of the spiral-shaped part substantially coincides with the centre of the reservoir and the spiral- shaped part therefore runs substantially along the inner wall of the reservoir, a good heat transfer from first medium to second medium is then achieved.

The shape of the spiral-shaped part preferably matches the shape of the inner wall of the reservoir in order to achieve a good heat transfer.

In a seventh preferred embodiment of the heat exchanger according to the invention the heat exchanger comprises a bottom, a cover and a peripheral wall arranged between the bottom and cover, and the peripheral wall is preferably cylindrical.

Although other shapes of the reservoir are also possible, a reservoir with a flat and parallel bottom and cover and a peripheral wall extending therebetween is

preferred, because such a heat exchanger has a more regular form and is thereby easier to place without dead spaces being created .

A cylindrical reservoir is preferred here because it is possible here to have the elongate element run from close to the centre of the round bottom to the round cover, wherein the partitions are arranged in a regular distribution around the elongate element. This increases efficiency.

In an eighth preferred embodiment of the heat exchanger according to the invention the at least one

partition extends from the bottom to the cover.

When the partitions extend from the bottom to the cover, this also being understood to mean extending over a substantial part between bottom and cover, the first medium is then subdivided in large part into compartments, this

increasing efficiency.

In a ninth preferred embodiment of the heat exchanger according to the invention the elongate tube lies at a right angle to the cover and the channel extends from close to the edge of the cover via the spiral-shaped part to a position close to the bottom and from close to the bottom via the elongate tube to a position close to the centre of the cover .

Such an embodiment has been found to produce a good efficiency while still requiring only 2.5 to 2.8 kWh of energy to obtain a quantity of heat equal to the heat produced from 1 m3 of gas, compared to about 8.7 kWh for a traditional electrical central heating.

In a tenth preferred embodiment of the heat exchanger according to the invention a valve with a controller is arranged close to the outlet.

By arranging a valve in or close to the outlet it is possible to close off the outlet, and more particularly to alternately move the valve over a period of time in the direction of the closed position and to subsequently open it (further) again over a (possibly different) period of time. By moving the valve in the outlet in the direction of the closed position over a period of time the contact time of the second medium in the heat exchanger is increased and the temperature of the second medium therefore increases. By subsequently opening the valve over a period of time it is then possible to discharge the second medium for further use. It is recommended to control this closure with a controller in order to thus achieve an optimal temperature. Such a combination can for instance comprise a magnetic valve with a pulse counter.

It can be advantageous in any case to not close the valve fully since the passage of second medium through the outlet hereby comes to a temporary standstill.

In an eleventh preferred embodiment of the heat exchanger according to the invention the controller is set to open and close the valve at intervals of between 10 and 40 seconds.

It has been found that selecting the above described period of time at between 10 and 40 seconds

contributes toward a sufficient rise in the temperature at the outlet without this resulting in a shortage of heated second medium in the most commonly occurring cases.

In a twelfth preferred embodiment of the heat exchanger according to the invention the heat exchanger further comprises an outer wall arranged around the reservoir at a distance from the reservoir.

By also arranging, in addition to the wall, an outer wall around the reservoir with an intermediate space under underpressure therebetween the chance of dissipation of heat that has been developed is reduced.

In a thirteenth preferred embodiment of the heat exchanger according to the invention an underpressure, preferably of at least about 1 bar, prevails in at least one of the reservoir and the space between the reservoir and the outer wall. The efficiency of the transfer is further increased by lowering the pressure in one of these spaces, but preferably both spaces. The chance of dissipation of heat is also reduced in the case of underpressure in the reservoir since long waves are broken down by the underpressure. The chance of overheating of the lamp wiring is moreover reduced.

The reservoir and/or the outer wall of the heat exchanger are preferably constructed from a plurality of parts so that they can be easily assembled and disassembled, this simplifying maintenance such as replacing the lamps. When underpressure prevails in any space in the heat exchanger, it is then advantageous to apply a seal such as O-rings for this purpose .

In a fourteenth preferred embodiment of the heat exchanger according to the invention the light source comprises :

- a first chamber filled with optionally inert gases which preferably comprise iodine and/or argon;

- a second chamber extending along and

preferably around the first chamber and filled with a gas which preferably comprises phosphorus and/or boron; and

- a filament which preferably comprises

tungsten extending through the first chamber, which filament comprises two connecting ends for connection to an electrical power source.

The gases in the first chamber here adhere to the filament in a zone around the filament, such as with strong preference the tungsten filament. Inert gas is

preferred because it displaces oxygen and thereby prevents oxidation of tungsten. Underpressure preferably prevails in the second chamber, i.e. a space with a lower pressure than the pressure of the outside air. Such a light source shows favourable yields. These and other aspects of the invention are further elucidated with reference to the accompanying figures.

Figure 1 shows a cross-sectional perspective view of a heat exchanger according to the invention.

Figure 2 shows a schematic top view of the heat exchanger according to figure 1 with cover omitted.

Figure 3 shows a flow diagram for the heat exchanger according to figure 1.

Figure 4 shows the development of the

temperature at the outlet in relation to time during use of the valve with controller.

Figure 5 shows a cross-section of a variant of a heat exchanger according to the invention.

Figure 6 shows a schematic view of a light source according to the invention.

Figure 1 shows a half of a heat exchanger 1. Heat exchanger 1 comprises a reservoir 2 with a bottom 3, a cover 4 and a peripheral wall 5 which extends therebetween and which is covered toward the interior with silver foil. Light sources (not shown) are arranged in reservoir 2. Running from an inlet 6 to outlet 7 is a channel 8 which is separated from the content of reservoir 2 and which is in heat-exchanging contact with the content of reservoir 2. The channel comprises from inlet 6 first a spiral-shaped part 9 with windings 10 which are pressed onto each other and adhered to each other using tin solder 11. Spiral-shaped part 9 runs from cover 4 in the direction of bottom 3, and from there connects via

connection 12 to elongate tube 13 which debouches into outlet 7. Arranged in regular distribution around elongate tube 13 are a number of partitions, of which partitions 14, 15 are shown, so that a number of compartments 16, 17, 18 with a similar volume are formed in reservoir 2. An outer wall 19 is further arranged around peripheral wall 5, with an insulating layer 20 between peripheral wall 5 and outer wall 19.

Figure 2 shows a top view of heat exchanger 1 with peripheral wall 5, outer wall 19 and insulating layer 20, elongate tube 13, and partitions 14, 15, 21, 22 which extend between tube 13 and peripheral wall 5. Compartments 16, 17, 18, 23 are formed by the partitions. Spiral lamps 24, 25, 26, 27 are arranged in compartments 16, 17, 18, 23.

Figure 3 shows heat exchanger 1 with inlet 6 and outlet 7 and, arranged close to outlet 7, magnetic valve 28, the position of which is controlled by a controller 29 which is connected to the valve and which invariably closes or opens valve 28 for an equal interval chosen from the range between 10 and 40 seconds.

It can be seen in figure 4 how the temperature of the second medium develops through this control of valve 28 by controller 29 at point 30. During a time period tl, in which valve 28 is gradually closed from the fully open

position, the temperature increases, while in time period t2, in which the valve is moved from a substantially closed position to the fully open position, the temperature falls.

Figure 5 shows a cross-section from the top side of a variant 50 of a heat exchanger according to the invention. Heat exchanger 50 comprises an outer wall 51, an inner wall 52, a space 53 which extends therebetween and which is under underpressure. Two channels extend inside inner wall 52. The first channel is constructed from a spiral-shaped part 54 and elongate part 55 connected to spiral-shaped part 54. The second channel is constructed from a spiral-shaped part 56 and an elongate part 57 connected to spiral-shaped part 56. The radius R2 of spiral-shaped part 56 is smaller than the radius Rl of spiral-shaped part 54. Underpressure prevails around channel parts 54, 55, 56, 57, 58 in reservoir 59.

Arranged in reservoir 59 are partitions 60 through which spiral-shaped parts 54, 56 pass in similar manner as shown in figure 1. This embodiment 50 is hereby almost the same as embodiment 1, although it has two channels here instead of one. In embodiment 50 the lamps are likewise placed between partitions 60 as described with reference to figure 2.

Figure 6 shows schematically a light source 100 used in heat exchanger 1. Light source 100 comprises a first closed chamber 101 and closed second chamber 102 extending around first chamber 101. Running through first chamber 101 and second chamber 102 is a tungsten filament 103 with two ends 104, 105 which can be connected to the respective poles of an electrical power source (not shown) . Where filament 103 does not extend through first chamber 101, the filament is provided with a protective layer 106. The gases present within first chamber 101 adhere to filament 103 in a zone 107 around filament 103.

Claims

1. Heat exchanger, comprising:

- a closed reservoir filled with a first medium;

least one channel which is arranged in the reservoir and through which a second medium flows from an inlet to an outlet;

least one light source arranged in the first medium in the reservoir, such as a spiral lamp; and

2. Heat exchanger as claimed in claim 1, wherein the heat exchanger comprises an elongate element arranged in the first medium, wherein the at least one

partition extends between the inner wall of the reservoir and the elongate element for the purpose of dividing the reservoir into a number of compartments.

3. Heat exchanger as claimed in claim 1 or 2, wherein the channel comprises an elongate tube which extends through the first medium.

4. Heat exchanger as claimed in claims 2 and 3, wherein the elongate element is the elongate tube.

5. Heat exchanger as claimed in any of the foregoing claims, wherein the channel comprises a spiral shaped part with a number of turns extending one above

another .

Heat exchanger as claimed in claim

wherein the turns are pressed onto each other and preferably attached to each other with adhering means such as tin solder.

7. Heat exchanger as claimed in claim 5 or 6, wherein the spiral-shaped part extends along the inner wall of the reservoir.

8. Heat exchanger as claimed in any of the foregoing claims, wherein the heat exchanger comprises a bottom, a cover and a peripheral wall arranged between the bottom and cover, and wherein the peripheral wall is

preferably cylindrical.

9. Heat exchanger as claimed in claim 8, wherein the at least one partition extends from the bottom to the cover.

10. Heat exchanger as claimed in claim 4, any of the claims 5 to 7 and claim 8 or 9, wherein the elongate tube lies at a right angle to the cover and wherein the channel extends from close to the edge of the cover via the spiral-shaped part to a position close to the bottom and from close to the bottom via the elongate tube to a position close to the centre of the cover.

11. Heat exchanger as claimed in any of the foregoing claims, wherein a valve with a controller is

arranged close to the outlet.

12. Heat exchanger as claimed in claim 11, wherein the controller is set to open and close the valve at intervals of between 10 and 40 seconds.

13. Heat exchanger as claimed in any of the foregoing claims, further comprising an outer wall arranged around the reservoir at a distance from the reservoir.

14. Heat exchanger as claimed in any of the foregoing claims, wherein an underpressure, preferably of at least about 1 bar, prevails in at least one of the reservoir and the space between the reservoir and the outer wall.

15. Heat exchanger as claimed in any of the foregoing claims, wherein the light source comprises: - a first chamber filled with optionally inert gases which preferably comprise iodine and/or argon;

- a second chamber extending along and

- a filament which preferably comprises tungsten extending through the first chamber, which filament comprises two connecting ends for connection to an electrical power source.