U.S. patent application number 13/279757 was filed with the patent office on 2012-04-26 for gas burner for a gas hob, gas cooker, and method for operating a gas hob.
This patent application is currently assigned to E.G.O. Elektro-Geratebau GmbH. Invention is credited to Martin Baier, Norbert Gartner, Michael Riffel, Uwe Schaumann, Wilfried Schilling, Konrad Schonemann.
Application Number | 20120097148 13/279757 |
Document ID | / |
Family ID | 44936185 |
Filed Date | 2012-04-26 |
United States Patent
Application |
20120097148 |
Kind Code |
A1 |
Schonemann; Konrad ; et
al. |
April 26, 2012 |
Gas Burner for a Gas Hob, Gas Cooker, and Method for Operating a
Gas Hob
Abstract
A gas burner for a gas cooktop has a gas burner body with gas
outlet openings. A thermogenerator is arranged above the gas burner
body, advantageously arranged concentrically relative to said gas
burner body and with the same shape and size, wherein the
thermogenerator is heated by said gas burner body. The
thermogenerator bears against a cooler pot base by way of its upper
face. The thermogenerator generates electrical energy which is used
to operate a control of the gas cooktop and which can be
stored.
Inventors: |
Schonemann; Konrad;
(Sulzfeld, DE) ; Riffel; Michael; (Oberderdingen,
DE) ; Schaumann; Uwe; (Oberderdingen, DE) ;
Schilling; Wilfried; (Kraichtal, DE) ; Gartner;
Norbert; (Ettlingen, DE) ; Baier; Martin;
(Ettlingen, DE) |
Assignee: |
E.G.O. Elektro-Geratebau
GmbH
Oberderdingen
DE
|
Family ID: |
44936185 |
Appl. No.: |
13/279757 |
Filed: |
October 24, 2011 |
Current U.S.
Class: |
126/39BA ;
126/39R |
Current CPC
Class: |
F23D 14/06 20130101;
F23M 2900/13003 20130101; F23N 5/00 20130101; F23N 2231/04
20200101; F24C 3/085 20130101; F23D 2900/14062 20130101; F24C 3/126
20130101 |
Class at
Publication: |
126/39BA ;
126/39.R |
International
Class: |
F24C 3/08 20060101
F24C003/08; F24C 7/00 20060101 F24C007/00; F24C 3/10 20060101
F24C003/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 25, 2010 |
DE |
DE102010042872.8 |
Claims
1. A gas burner for a gas cooktop comprising a gas burner body, the
gas burner body comprising gas outlet openings, wherein a
thermogenerator is arranged above said gas burner body.
2. The gas burner as claimed in claim 1, wherein said
thermogenerator is concentric relative to said gas burner.
3. The gas burner as claimed in claim 1, wherein said
thermogenerator has the same shape as said gas burner.
4. The gas burner as claimed in claim 1, wherein said
thermogenerator is in the form of a disk.
5. The gas burner as claimed in claim 1, wherein said
thermogenerator is held above said gas burner body by resilient
holding means and is pushed upward to bear against a lower face of
a pot which is located above said gas burner, wherein said abutment
is subject to an action of a spring force.
6. The gas burner as claimed in claim 1, wherein said gas burner
openings are arranged in one plane, and wherein said
thermogenerator is arranged approximately parallel to said plane of
said gas burner openings.
7. The gas burner as claimed in claim 1, wherein a lower first heat
conduction element is arranged between said gas burner body and
said thermogenerator, wherein said lower first heat conduction
element is in the form of a disk.
8. The gas burner as claimed in claim 7, wherein said lower first
heat conduction element is larger than said gas burner body,
wherein said lower first heat conduction element projects laterally
beyond said gas burner body by at least 10% of a diameter of said
gas burner body.
9. The gas burner as claimed in claim 8, wherein said lower first
heat conduction element has, in its edge region, recesses in the
form of incisions.
10. The gas burner as claimed in claim 1, wherein a further upper
second heat conduction element is provided on an upper face of said
thermogenerator, wherein said upper second heat conduction element
is in the form of a disk and is approximately the same size as said
thermogenerator.
11. The gas burner as claimed in claim 1, wherein said gas burner
is in the form of a single-ring burner with a single gas burner
body and a single ring of gas burner openings in said gas burner
body.
12. The gas burner as claimed in claim 1, wherein said gas burner
is in the form of a two-ring burner with an inner gas burner body
and an outer gas burner body, wherein said thermogenerator is
arranged above said inner gas burner body.
13. The gas burner body as claimed in claim 12, configured so that
a gas flame is formed on the inner gas burner body in a manner
which cannot be regulated but rather always operates with a thermal
power which is designed in such a way that said thermogenerator
generates a required electrical power.
14. The gas burner as claimed in claim 13, configured so that a gas
flame is formed on said outer gas burner body in a manner which can
be regulated.
15. The gas burner as claimed in claim 1, wherein said
thermogenerator is part of a pot support for a pot and is arranged
on said gas burner such that the thermogenerator cannot move in the
vertical direction.
16. The gas burner as claimed in claim 1, wherein said
thermogenerator is designed such that the thermogenerator can be
removed from said gas burner body and from said gas burner.
17. A gas cooktop having at least one gas burner comprising a gas
burner body, the gas burner body comprising gas outlet openings,
wherein a thermogenerator is arranged above said gas burner body,
wherein said thermogenerator has an electrical connection to a
power supply of said gas cooktop, wherein said power supply is
connected to a controller of said gas cooktop.
18. The gas cooktop as claimed in claim 17, wherein said power
supply has an energy store comprising a rechargeable battery.
19. The gas cooktop as claimed in claim 17, wherein said gas
cooktop has at least one electrical ignition device for igniting
the at least one gas burner.
20. The gas cooktop as claimed in claim 17, wherein said gas
cooktop is designed without an electrical connection or an option
of being electrically connected to a mains power supply system.
21. The gas cooktop as claimed in claim 17, wherein said electrical
power of said thermogenerator is designed to be higher than an
actual power required by said controller of said gas cooktop in
order to store excess electrical energy from said thermogenerator
in the energy store.
22. The gas cooktop as claimed in claim 17, wherein said gas
cooktop has electronically controlled electrical gas valves for
supplying gas to said gas burners, said electrical gas valves
configured such that at a minimum power setting in a gas burner in
the form of a two-ring burner with an inner gas burner and an outer
gas burner, said inner gas burner is ignited and burns with a
specific thermal power, wherein said specific thermal power is
designed such that said thermogenerator generates a required
electrical power for supplying an electronic controller, wherein
said inner gas burner burns with a higher thermal power when said
gas valve is opened further and then said outer gas burner can be
ignited, and a thermal power of said outer gas burner can be
regulated.
23. A method for operating a gas cooktop comprising a gas burner,
the gas burner comprising a gas burner body which has gas outlet
openings, wherein a thermogenerator is arranged above said gas
burner body, wherein said thermogenerator has an electrical
connection to a power supply of said gas cooktop, wherein said
power supply is connected to a controller of said gas cooktop, the
method comprising: checking whether a pot is placed over said gas
burner and has cooled a cold side of the thermogenerator, wherein
the thermogenerator produces a signal have a thermoelectric
voltage; and evaluating the signal by a controller of the gas
cooktop to determine whether the pot is present.
24. A method for operating a gas cooktop comprising a gas burner,
the gas burner comprising a gas burner body which has gas outlet
openings, wherein a thermogenerator is arranged above said gas
burner body, wherein said thermogenerator has an electrical
connection to a power supply of said gas cooktop, wherein said
power supply is connected to a controller of said gas cooktop, the
method comprising: monitoring a temperature of a pot base of a pot
placed on the gas cooktop using a profile of a thermoelectric
voltage at the thermogenerator; determining a phase of a constant
temperature of the pot base during operation of the gas burner
followed by a subsequent rapid increase in temperature of the pot
base; determining by the controller of the gas cooktop that the pot
placed on the gas cooktop has boiled dry; and outputting by the
controller a signal to turn off the gas burner.
25. A method for operating a gas cooktop comprising a gas burner,
the gas burner comprising a gas burner body which has gas outlet
openings, wherein a thermogenerator is arranged above said gas
burner body, wherein said thermogenerator has an electrical
connection to a power supply of said gas cooktop, wherein said
power supply is connected to a controller of said gas cooktop,
comprising: detecting by the controller a thermal power generated
at the gas burner by a gas throughflow rate to the gas burner by
detecting an open position of the gas value; comparing the thermal
power with the electrical power output by the thermogenerator and
based on a result of the comparison determining a temperature of a
pot base that has been placed on the gas burner.
26. The method as claimed in claim 25, wherein detected measurement
variables comprising the detected thermal power and detected open
position of the valve are used to regulate said cooking processes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of DE 102010042872.8
filed on Oct. 25, 2010, the contents of which are expressly
incorporated herein by reference in its entirety.
FIELD OF APPLICATION
[0002] The invention generally relates to a gas burner for a gas
cooktop, to a gas cooktop which is provided with said gas burner,
and also to a method for operating a gas cooktop of this kind.
BACKGROUND
[0003] Thermogenerators are known per se for generating electrical
energy. To this end, a hot side of the thermogenerator is subjected
to the action of heat or heated, while the heat is drawn or output
on a cold side. However, the degree of efficiency of a
thermogenerator of this kind is usually only 3% to 5%, and
therefore the amount of thermal energy that has to be conducted by
the thermogenerator is considerably more than the amount of
electrical energy obtained. On the other hand, a sufficient amount
of thermal energy is available in many applications.
[0004] DE 10 2007 058 945 A1 discloses installing a thermogenerator
on a gas burner in a gas cooktop. There, the thermal energy which
is conducted by the thermogenerator is diverted away toward the gas
cooktop. The cold side of the thermogenerator therefore faces the
gas cooktop which firstly heats up, this being negative.
Furthermore, this thermal energy is lost to the cooking
process.
SUMMARY
[0005] The disclosure is generally directed to providing a gas
burner, a gas cooktop and also a method for operating a gas burner
of this kind as cited in the introductory part and with which
problems which arise in the prior art can be avoided and, in
particular, an efficient and structurally simple way of generating
electrical energy at a gas burner of a gas cooktop by means of a
thermogenerator is provided.
[0006] Advantageous and preferred refinements of the invention are
the subject matter of the further claims and will be explained in
the text which follows. In the process, some of the features cited
in the text which follows are explained only in respect of the gas
burner, the gas cooktop or one of the methods. However,
irrespective of this, they are intended to be applicable to the gas
burner, the gas cooktop and also the methods. The wording of the
claims is incorporated in the content of the description by express
reference.
[0007] According to one embodiment, a gas burner, which has a gas
burner body which is customary per se and has gas outlet openings,
has a thermogenerator arranged above said gas burner body. The
thermogenerator can be particularly advantageously arranged
concentrically relative to the gas burner body and/or have the same
shape or the same or a similar size. As a result, it is possible
for the hot side of the thermogenerator to be subjected to the
action of thermal energy by the gas burner body itself, this
thermal energy otherwise being introduced at the top into a cooking
vessel which is placed above the gas burner. The cold side of the
thermogenerator is, as it were, cooled by this cooking vessel. This
occurs either due to the emission of heat to the base of the pot
which is located above said thermogenerator or else, in a preferred
refinement of the invention, on account of the cold side of the
thermogenerator bearing against the base of the pot. This can be
achieved in a particularly preferred manner by flexible or
resilient holding means which hold the thermogenerator above the
gas burner body and primarily push said thermogenerator against the
lower face of the cooking vessel.
[0008] These and further features can be gathered not only from the
claims but also from the description and the drawings, where the
individual features can be realized in each case by themselves or
in combination in the form of subcombinations in an embodiment of
the invention and in other fields and can constitute advantageous
and inherently patentable embodiments for which protection is
claimed here. The subdivision of the application into individual
sections and subheadings do not restrict the general validity of
the statements made thereunder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Exemplary embodiments of the invention are schematically
illustrated in the drawings and will be explained in greater detail
in the text which follows. In the drawings:
[0010] FIG. 1 shows a first embodiment of a gas burner in a gas
cooktop as a single-ring burner with a heat conduction element and
a thermogenerator above it,
[0011] FIG. 2 shows a further embodiment of a gas burner with a
thermogenerator which is part of a pot support, and
[0012] FIG. 3 shows a further embodiment of gas burner which is in
the form of a two-ring burner.
DETAILED DESCRIPTION
[0013] It has been found that although a thermogenerator which has
been put in position directly on the upper face of the gas burner
body can absorb the thermal energy very well, it is considered to
be more expedient to use radiant heat for the input of thermal
energy and to design the thermogenerator with its cold side
directly against the lower face of the pot for output purposes
since, under certain circumstances, it is mechanically relatively
difficult to simultaneously achieve abutment against the lower face
of a pot which has been placed on in order to draw away the thermal
energy on the cold side. A spring device may be provided for this
purpose and can be designed in various ways but which, for
temperature resistance purposes, is advantageously composed of
metal and therefore can be, for example, in the form of a plate
spring or helical spring provided on the upper face of the gas
burner body.
[0014] A thermogenerator is advantageously in the form of a disk,
with its diameter being considerably larger than its thickness or
height. The thermogenerator is particularly advantageously arranged
approximately parallel to the plane of the gas burner openings.
This usually also means that it is arranged parallel to a pot base,
this being advantageous primarily for good abutment against said
pot base.
[0015] In one embodiment, provision may be made for the
thermogenerator to be larger than the gas burner body or to
laterally protrude beyond said gas burner body. Therefore, the gas
flames emerging from the gas outlet openings can be used at least
partially to heat up the hot side of the thermogenerator, so that
the thermal energy can be introduced in a very effective manner. If
the hot side of the thermogenerator is located very close to the
upper face of the gas burner body, the transfer of the thermal
energy is likewise very easily possible and it is possible for this
transfer to be achieved even without the gas flame having to
directly reach the thermogenerator.
[0016] As an alternative embodiment to the above-described options,
a lower first heat conduction element can be arranged between the
gas burner or the gas burner body and the thermogenerator. This
heat conduction element is advantageously likewise in the form of a
disk and arranged such that it is approximately parallel to the
plane of the gas burner openings, that is to say, preferably also
parallel to the thermogenerator, and at a distance therefrom. The
first heat conduction element is intended to bear directly against
the hot side of the thermogenerator for the best possible
introduction of thermal energy. The first heat conduction element
can also be larger than the gas burner body, for example as was
described above, for a possible design of the thermogenerator, and
therefore the gas flames directly heat the heat conduction element.
To this end, said heat conduction element can project laterally
beyond the gas burner body by at least 10% of the diameter of the
gas burner body or of a ring of the gas burner openings, preferably
by a maximum of 20%. Therefore, the lower first heat conduction
element can, as it were, capture a portion of the thermal energy
and pass it to the thermogenerator, this thermal energy being
generated by the gas burner by means of the gas flames in order to
thus heat the pot, which is placed on, via its pot base.
[0017] In another, provision can be made for the lower first heat
conduction element to have, in its edge region, holes and/or
recesses in the form of incisions with projections located between
them. An edge of this kind of the first heat conduction element can
be substantially in the form of a toothed wheel. This can serve to
heat the projecting projections, as it were, to a particularly
pronounced extent by the gas flames running beneath them. Depending
on the power configuration, the holes or recesses can be situated
over the gas flames, and therefore these flames can burn through
substantially between the projections and, as a secondary effect,
heat up the projections. This ensures that a large portion of the
thermal energy which is generated by the gas burner is introduced
into the pot base. As an alternative, provision can be made for the
projections to be situated directly over the gas flames or the gas
burner openings which form said gas flames. However, said
projections are intended to protrude laterally beyond the gas
burner body only to such an extent that the projections are heated
to a pronounced extent for introducing thermal energy into the
thermogenerator at a level which is sufficient at a low power level
only when the gas flames are small in accordance with this low
power level. If a higher power level is selected, the gas flames
burn more vigorously or are longer and extend far beyond the
projections which then continue to be heated. However, a large
portion of the thermal energy which is generated by the gas flames
is then passed, as desired, to the pot base.
[0018] In a yet further embodiment, a further upper second heat
conduction element can be provided above or on the upper face of
the thermogenerator, that is to say on the cold side. The heat
conduction element is particularly advantageously likewise in the
form of a disk, as are the thermogenerator and the above-described
first heat conduction element. The heat conduction element can
advantageously also be approximately the same size as the
thermogenerator itself, or alternatively also somewhat larger
again, similarly to the first heat conduction element. Therefore,
the thermal energy can be transferred particularly effectively from
the cold side of the thermogenerator to the pot base. However, the
upper second heat conduction element should not be excessively
large, so that the gas flames which are generated by the gas burner
can continue to ensure sufficiently effective and rapid heating of
the pot base. The second heat conduction element also serves for
the improved conduction of heat, in this case away from the
thermogenerator to the pot base.
[0019] In another embodiment of a gas burner, said gas burner is a
so-called single-ring burner with a single gas burner body and a
single group of gas burner openings in said gas burner body, said
gas burner openings being provided on the outer circumference of
said gas burner body in the form of a ring, as is customary.
[0020] A spring device can advantageously also be provided on a
removable cover of a gas burner body, for example also equally as a
unit together with the thermogenerator itself. This unit may
comprise a cover for the gas burner body, possibly with a spring
and the thermogenerator and also possibly including the
above-described heat conduction elements, and can therefore be
fitted and removed. This is advantageous when only one single such
unit is intended to be provided for the gas cooktop according to
the invention for cost reasons, and therefore said unit is then
used in each case on the gas burner which is to be operated.
[0021] In another embodiment, the gas burner is in the form of a
two-ring burner. The gas burner has an inner gas burner body and an
outer gas burner body. In this case, the thermogenerator is
arranged above the inner gas burner body since this is usually
always in operation when the gas burner is operating. A gas flame
is advantageously formed at the inner gas burner body in a manner
which cannot be regulated, but rather which always operates with a
thermal power which is designed in such a way that the
thermogenerator generates a required electrical power. A gas flame
is formed at the outer gas burner body in a manner which can be
regulated, and therefore, if the intention is to operate with a
power which goes beyond the thermal power of the first inner gas
burner body, the second outer gas burner body is, as it were,
switched on. This can ensure that, during operation of this
two-ring burner, the required thermal energy is always present at
the thermogenerator and therefore the required electrical power is
generated. Operation with a minimum thermal power at the gas burner
body is also applicable for the above-described single-ring burner
in any case.
[0022] In a further embodiment, it is possible to design the
thermogenerator itself as a pot support or as part of a pot support
of this kind. To this end, the thermogenerator can be arranged on
the gas burner such that it cannot move in the vertical direction,
so that it is also stable, in order to be able to place a pot on
it. The thermogenerator is advantageously arranged centrally over
the gas burner body and has outwardly leading connections to
support means on the gas cooktop beneath it, advantageously three
to provide standing stability. Therefore, yet further bearing
points for the pot are provided in an outer region around the
thermogenerator, so that said pot does not bear only on the
thermogenerator. In this case, the thermogenerator is intended to
be thermally insulated as well as possible from the other parts of
the pot support, so that the thermal energy which is to be drawn
from the cold side is introduced into the pot as far as possible.
The situation of too much thermal energy being drawn from the
heating process of the pot can be avoided as a result.
[0023] As has already been described, the thermogenerator can
advantageously be designed in a removable manner on its own or as a
unit together with part of the gas burner body, for example the
cover of the gas burner body. This is possible, firstly, for a case
in which it is not required at all, for example because the gas
cooktop is connected to a mains power supply (e.g., household
power) system. Furthermore, this can result primarily in a
thermogenerator of this kind not being provided on each gas burner
of a gas cooktop but rather fewer or, particularly advantageously,
only one single thermogenerator being provided.
[0024] In the case of a gas cooktop according to one, provision is
made for the thermogenerator to have an electrical connection to a
power supply means of the gas cooktop. This electrical connection
is intended to exhibit sufficient thermal resistance to
advantageously be routed laterally away from the thermogenerator,
downward, to the gas cooktop. Since it is inevitably also acted on
by the gas flames from the gas burner in the process, care should
be taken that it also has sufficient thermal insulation in this
respect. Firstly, said electrical connection is intended to cross
the gas flame as far as possible above said gas flame. Secondly,
electrical and thermal insulation means can have a glass fiber
fabric, and plastic or the like can be dispensed with, or have only
plastic with a high thermal resistance, such as silicone or the
like.
[0025] The controller of the gas cooktop is advantageously an
electronic controller which has, for example, in addition to
program sequences which can be stored, touch-operated switches
which are electronically triggered and evaluated. Furthermore,
energy store in the form of a rechargeable battery is
advantageously contained in the power supply or said power supply
has a rechargeable battery. Therefore, any excess electrical energy
from the thermogenerator which may have been generated can be
stored for starting operation of the gas burner or of the gas
cooktop, this being required, on account of there being an
electronic controller, before the thermogenerator can actually
generate electrical energy.
[0026] In an advantageous embodiment, the gas cooktop can have
electrical ignition devices for igniting the gas burners.
Furthermore, devices such as flame monitoring means or the like can
be provided.
[0027] In another advantageous embodiment, a gas cooktop can have
both single-ring burners and two-ring burners, in particular as
have been described above.
[0028] In a yet further embodiment, the gas cooktop can be designed
such that it can be operated completely without an electrical
connection to a mains power supply system. Under certain
circumstances, it can even be designed entirely without the option
of being electrically connected or without a connection cable. In
this case, the electrical energy for operating the abovementioned
control means and possibly also the gas valves or other functional
devices is drawn solely from said rechargeable battery. In this
case, the rechargeable battery also has to be kept charged as far
as possible. A gas cooktop of this kind can advantageously also be
operated in locations or in an environment which have/has a gas
supply, for example by gas cylinders, but are/is not connected to
the mains power supply system. Therefore, the concepts disclosed
herein are also suitable for portable gas cooktops, for example for
camping.
[0029] It may be advantageous, specifically for charging the
above-mentioned rechargeable battery, to design the electrical
power of the thermogenerator to be higher than the power actually
acutely required in each case by the controller of the gas cooktop
or electrical gas valves or the like. In this way, excess
electrical energy from the thermogenerator can be stored in the
energy storage means for a further operation.
[0030] As has been discussed above, electrically or electronically
controlled gas valves are advantageously provided in the gas
cooktop. These gas valves can be designed such that, in the case of
an above-described two-ring burner, only the inner gas burner is
ignited and burns with a specific thermal power at a minimum power
setting. This thermal power is designed such that the
thermogenerator operates effectively and can advantageously
generate the required electrical power for supplying the electronic
controller or operates with as high a degree of efficiency as
possible. Therefore, in addition to power being supplied to the gas
cooktop itself, said energy storage means can also be charged. When
the gas valve of the inner gas burner is opened further, said inner
gas burner burns with a higher thermal power, with the outer gas
burner then being ignited with the further increase and it
therefore being possible for the thermal power of said outer gas
burner to be fully regulated.
[0031] Therefore, in a method disclosed herein for operating an
above-described gas cooktop, it is not only possible to obtain
electrical energy by means of the thermogenerator, without an
excessive amount of thermal energy for heating the pot being drawn,
but rather, further functions can also be achieved by the
thermogenerator. For example, for a pot identification function, a
check can be made as to whether a pot is placed over the gas burner
by the thermoelectric voltage being monitored. If the cold side of
the thermogenerator is specifically not cooled by a pot base which
has been placed on or put in position when the gas burner is
operating, no thermoelectric voltage or only a very low
thermoelectric voltage is produced at the thermogenerator. Since a
controller can check whether the gas burner is operating and, with
reference to the position of the gas valve, it can also check the
gas throughflow rate and the thermal power at which said gas burner
is operating. This information can be used to identify that no pot
has even been placed on. This can be evaluated by the controller as
a pot being missing and possibly be output in the form of a signal
or the like.
[0032] In a further embodiment of a method for operating an
above-described gas cooktop, the thermoelectric voltage at the
thermogenerator can again be monitored and therefore the
temperature of the pot base of the pot which has been placed on can
be monitored. This temperature determines, specifically, the
temperature on the cold side of the thermogenerator and therefore
the thermoelectric voltage generated. In this case, provision can
be made, after a relatively long phase of an approximately constant
temperature of the pot base owing to an approximately constant
thermoelectric voltage during operation of the gas burner, for the
control means to draw the conclusion that the pot which has been
placed on has boiled dry if there is a subsequent rapid increase in
temperature due to an increase in the thermoelectric voltage.
Therefore, the temperature of its pot base increases to a great
extent. The controller can then output a corresponding signal and,
for example, switch off the gas burner.
[0033] In the case of a yet further method disclosed herein for
operating a gas cooktop with a two-ring burner, provision may be
made for the control means to detect the thermal power at the gas
burner. To this end, the gas throughflow rate to the gas burner can
be monitored advantageously by detecting the passage or an open
position of the gas valve. This can, in turn, be compared with the
electrical power which is output by the thermogenerator or the
thermoelectric voltage. The result of this comparison can be used
to at least approximately determine the temperature of a pot base,
in particular the relative profile of said temperature. The
measurement variables or the detected and determined values can
advantageously be used to regulate cooking processes.
[0034] Turning now to the figures, FIG. 1 illustrates a gas cooktop
11 with a cooktop plate 12. According to one embodiment, said gas
cooktop has a gas burner 14 which comprises a gas burner body 15
with gas outlet openings 16 which are arranged in said gas burner
body in the form of a ring, as is customary. The gas burner 14 is
supplied with gas by means of a gas feed line 18, the passage of
gas through said gas feed line being regulated by an electrically
controllable gas valve 19. The gas valve 19 is controlled by a
controller 20 of the gas cooktop 11. This controller 20 can be
designed either only for this gas burner 14 alone or else for all
the gas burners or, advantageously, for the entire gas cooktop
11.
[0035] A heat conduction element 23 is held above the gas burner 14
on the upper face of the gas burner 14 or the gas burner body 15,
which upper face can be formed, for example, by a removable cover
(not illustrated here) or the like, by means of a spring 21 which
is illustrated here only schematically as a helical spring. The
heat conduction element 23 is in the form of a disk and is somewhat
larger than the gas burner body 15, but not by too much. The heat
conduction element is composed of a material which conducts heat
well, for example aluminum or copper, and under certain
circumstances die-cast metal.
[0036] A thermogenerator 25 is arranged on the upper face of the
heat conduction element 23 such that it bears flat on said upper
face, specifically such that it sits centrally on said upper face
and therefore is concentric relative to the gas burner body 15. The
thermogenerator 25 is in the form of a disk and is considerably
thicker than the heat conduction element 23, but this does not
necessarily have to be the case. Connection lines 27 of the
thermogenerator are schematically illustrated and emerge from the
side of said thermogenerator and are routed to an energy store 29
of the gas cooktop 11. The energy store 29 in turn is connected to
the controller 20. The energy store has a rechargeable battery (not
illustrated) or some other energy storage means which can be
charged. Furthermore, the controller 20 can be supplied with energy
not only by the energy store 29, but also directly by the
thermoelectric voltage or electrical energy which is generated by
the thermogenerator 25.
[0037] In order to ensure that the connection lines 27 which, as
can be seen, are clearly laterally routed past the gas flames 17
have a sufficient degree of thermal resistance to said gas flames,
the connection lines can have a temperature-resistant insulation.
This temperature-resistant insulation can be, on the one hand, an
oxide surface on a metal, which oxide surface is not electrically
conductive or exhibits poor electrical conductivity, so that two
metal lines or metal wires emerge from the thermogenerator 25 as
connection lines 27. As an alternative, said temperature-resistant
insulation can also comprise customary metal wires with a
sufficiently good degree of electrical and thermal insulation due
to a surrounding glass fiber fabric or the like. As an alternative,
high-temperature-resistant silicone mixtures can also be added or
used.
[0038] FIG. 1 also shows that the upper face of the thermogenerator
25 bears flat and directly against the lower face of a pot base 31
of a pot 30. In order to ensure effective abutment, the spring 21
is also provided. As has already been explained above, the hot side
of the thermogenerator 25 is therefore also at the bottom. In this
case, thermal energy is passed from the gas burner 14 or from the
gas flames 17 via the heat conduction element 23 to the hot side
and into the thermogenerator 25. The thermal energy is again output
to the pot base 31 on the cold side which bears, on account of the
spring 21, in a resilient manner and flat against the pot base 31
of the pot 30. Therefore, the thermogenerator 25 is firstly cooled
by the pot base 31 to achieve the temperature difference which is
required for operation. At the same time, the thermal energy is not
lost to the heating process, but is actually input into the actual
target, specifically the pot base 31 or the pot 30, via the
diversion through the thermogenerator 25.
[0039] Similarly to the lower heat conduction element 23, a further
heat conduction element can also be provided on the upper face of
the thermogenerator 25, specifically in order to improve the output
of the thermal energy from the thermogenerator 25 to the pot base
31. However, this actually makes sense only if this heat conduction
element were considerably larger than the thermogenerator, in order
to distribute the thermal energy which is output by said heat
conduction element over a larger surface area of the pot base 31.
Although this would improve the output of thermal energy from the
thermogenerator 25 and therefore improve the degree of efficiency
of said thermogenerator, it also simultaneously has an adverse
effect on the input of heat from the gas burner 14 or the gas
flames 17 into the pot base 31, and therefore this is actually
inadvisable. Instead, the thermogenerator 25 should have a size
such that it has, as is illustrated, a diameter which is somewhat
smaller than the gas burner body 15 and therefore the ring of gas
outlet openings 16.
[0040] The main improvement in the degree of efficiency of the
thermogenerator 25 or increase in the electrical power which is
generated by said thermogenerator takes place via the lower heat
conduction element 23 which is, as it were, heated to a greater
extent by the gas burner 14 or the gas flames 17 on account of its
relatively large diameter than would be the case for the
thermogenerator 25 alone. To this end, the heat conduction element
23 can, as has been described in the introductory part, have a
shape which differs from a round disk in line with the ring of gas
outlet openings 16. By way of example, projections and recesses in
the form of a toothed wheel can be provided, with said projections
and recesses advantageously being matched to the gas outlet
openings 16. The gas outlet openings 16 determine, specifically,
the profile of the gas flame 17. The projections can be situated
exactly above the gas outlet opening 16 and therefore above the gas
flames 17 in order to achieve particularly good heating. As an
alternative, they can extend between said gas flames in order to be
heated by them somewhat for sufficiently good introduction of
thermal energy into the thermogenerator 25. At the same time, they
draw some, but not too much, energy from the heating process of the
pot base 31 as a result.
[0041] The spring 21, the heat conduction element 23 and the
thermogenerator 25 advantageously form, together with the
connection lines 27, an independent unit. Each gas burner of the
gas cooktop 11 has a unit of this kind, and therefore electrical
power for the energy store 29 is also generated each time a gas
burner is operation, with all the thermogenerators obviously being
connected to the same energy store 29 in this case.
[0042] However, in order to save on this expenditure, it is also
possible to make provision for this unit to be removed from the gas
burner 14 or the gas burner body 15, for example from the removable
cover of said gas burner body, or else to be integrally formed with
the cover. Furthermore, the connection lines 27 can be long enough
to reach each gas burner of the gas cooktop. As an alternative, the
connection lines 27 can be inserted and removed via detachable plug
connections on the gas cooktop 11 or on the cooktop plate 12 as
electrical connections.
[0043] This unit with the thermogenerator 25 is then fitted
precisely to that gas burner which is intended to be operated. As a
result, it is possible to ensure that electrical energy is also
always generated when any gas burner of the gas cooktop 11 is
burning. The electrical energy from the energy store 29 can also be
used to operate the gas valve 19 which is controlled by the
controller 20.
[0044] A simpler embodiment of the described gas cooktop is a
refinement without a heat conduction element or a heat conduction
plate. Although this may be less effective because the
thermogenerator is only partially and additional non-uniformly
heated, a considerably lower-cost design can be achieved on account
of the saving on the heat conduction plate.
[0045] In a further alternative embodiment of a gas cooktop 111,
FIG. 2 once again illustrates a gas burner 114 similar to that from
FIG. 1 with a gas burner body 115, gas outlet openings 116 and gas
flames 117. The gas cooktop 111 also has a thermogenerator 125
which, however, is in the form of a ring, that is to say with an
opening in the middle, but this does not necessarily have to be the
case. However, the thermogenerator 125 is primarily connected,
radially on the outside, to the pot support arms 133, it being
possible, for example as is customary, for four of these pot
support arms 133 to be provided in the form of a star and form a
cross together with the thermogenerator 125. The pot 130 can be
placed on said thermogenerator by way of its pot base 131.
Insulating parts can be provided between the thermogenerator 125
and the pot support arms 133, said insulating parts preventing
thermal short-circuiting of the outer limbs of the thermogenerator
by the pot support arms.
[0046] The pot support arms 133 are placed radially on the outside
on pot support connection pieces 134, with insulating parts 136
being arranged between these two components. The intended result of
this is that not too much thermal energy is output to the pot
support connection pieces 134, and therefore to the cooktop plate
112, laterally on the outside via the pot support arms 133. The
thermal energy would specifically firstly only result in
interference or could cause damage in said cooktop plate.
Furthermore, it would fail to heat the pot 130.
[0047] Connection lines of the thermogenerator 125, and the gas
valve, the controller and the energy store according to FIG. 1 are
not illustrated in FIG. 2. However, they could be provided in the
same way, as can be easily imagined. Connection lines for the
thermogenerator 125 can run either very close to the pot support
arms 133 and the pot support connection pieces 134 and therefore
also slightly removed from the gas flames 117. As an alternative,
they can also run in said pot support arms and pot support
connection pieces if said pot support arms and pot support
connection pieces are hollow, and said connection lines are
therefore very well protected.
[0048] One advantage of the arrangement in FIG. 2 is that no
mechanically movable parts are necessary. However, the construction
of the pot support is may be actually more complicated and a
dedicated thermogenerator 125 is provided for each gas burner
114.
[0049] Furthermore, the thermogenerator 125 could also be in the
form of a continuous closed disk, similarly to in FIG. 1. In a
further embodiment, a heat conduction element could also be
provided on the lower face again, and possibly also on the upper
face, as illustrated and described in FIG. 1. It would be
advantageous to provide a heat conduction element of this kind
primarily on the lower face of the thermogenerator 125, that is to
say, on the hot side.
[0050] FIG. 3 illustrates a further embodiment in the case of a gas
cooktop 211; specifically a gas burner 214 is in the form of
so-called two-ring burner in this case. The gas burner therefore
has an inner gas burner 214a and an outer gas burner 214b, as is
known in principle. The smaller inner gas burner 214a with a gas
burner body 215a and gas outlet openings 216a is arranged above the
larger outer gas burner 214b. However, this does not have to be the
case; they could also be arranged approximately on the same plane
such that they are situated concentrically one in the other.
[0051] A thermogenerator 225 with a lower heat conduction element
223a, which is somewhat smaller and is in the form of a downwardly
sloping disk, is arranged at the top of the inner gas burner 214a
or the gas burner body 215a. The upper face, that is to say the
cold side, of the thermogenerator 225 again bears flat and directly
against the lower face of a pot base 231 of a pot 230 which is
intended to be heated. In this case, the pot 230 is situated on the
pot support connection pieces 234 which are illustrated on the
outside.
[0052] The second outer gas burner 214b has a gas burner 215b with
gas outlet openings 216b from which large and long gas flames 217b
emerge. While the smaller gas flames 217a of the inner gas burner
214a at least partially act on the heat conduction element 223 or
the thermogenerator 225, the outer gas flames 217b of the outer gas
burner 214b reach only the pot base 231 or introduce thermal energy
only to said pot base. The thermogenerator 225 is therefore
supplied or heated only by the inner gas burner 214a.
[0053] Similarly to FIG. 2, FIG. 3 does not illustrate the gas
valves for supplying gas to the two gas burners 214a and 214b, the
controller, the energy store and the electrical connection lines
for the thermogenerator 225 either. However, they can likewise be
provided as in FIG. 1. Furthermore, the thermogenerator 225 can
also be arranged such that it can be either fixed to or removed
from the gas burner 214a in FIG. 3.
[0054] The operating options in respect of the two gas burners 214a
and 214b as two-ring burners according to FIG. 3 have already been
adequately discussed in the introductory part. Like the gas burners
in FIGS. 1 and 2, the inner gas burner 214a is also always intended
to burn with a thermal power such that enough energy is generated
for operating a control means according to FIG. 1, as far as
possible also an electrically operated gas valve, in an illustrated
configuration of the thermogenerator 225. However, in a two-ring
burner as in FIG. 3, the major portion of the thermal energy is
usually generated by the outer gas burner, and therefore the low
thermal power loss due to the provision of the thermogenerator 225
is not negative.
[0055] Possible evaluation methods at the thermogenerators by the
control means for temperature measurement and for pot
identification have likewise already been discussed in detail
above.
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