This application is a U.S. national phase application filed under 35 U.S.C. § 371 of International Application PCT/EP2017/065051, filed Jun. 20, 2017, designating the United States, which claims priority from European Application Number 16175278.7, filed Jun. 20, 2016.
The invention relates to a heating system component for heating fluid media in a heating system of a household appliance, in particular, to heating system component comprising at least one temperature sensor.
For many types of domestic appliances or domestic machines, it is necessary to heat up a fluid medium, such as for example water. Heating up can be caused by means of one or more heating systems. To that extent, a medium circuit can be provided, a pump arranged in the circuit causing circulation of the medium in the circuit.
Basic aspects of such heating systems are that, like all other components of the medium circuit, the system is to take up only a small amount of space and is to be inexpensive to produce. Furthermore, the heating system shall be simple to assemble. Reliable safeguarding of the heating system must be guaranteed upon the occurrence of a critical operating condition which can result in plastic components within the domestic appliance melting or catching fire. In case of some domestic appliances, it may further be necessary to prevent the medium to be heated from exceeding a predetermined temperature. For example, in the case of a dishwashing machine, it may be necessary to prevent the washing water from exceeding its boiling temperature.
US patent application 2006/0236999 A1 discloses a heating system for heating fluid media, in particular for domestic appliances, including a carrier unit, a heating unit arranged on the carrier unit and a heat transfer element which is arranged on the carrier unit and comprising a material which is a good conductor of heat. On the heat transfer element, temperature safety devices are mounted by fixing elements via corresponding through apertures.
It is a general object of the manufacture of heating systems and heating system components to provide ever smaller and more compact construction parts, which provide a sufficient heating power (if not the same heating power as before). It is a further object to reduce manufacturing costs.
In addition, when using conventional temperature monitoring and/or control elements (such as, e.g., thermal fuses) with continuous-flow water heaters, there is a problem when the temperature monitoring and/or control elements are fixed with, e.g., one or more screws, to a mounting plate. That is, when the mounting plate is soldered to the heating unit, it may curve. Further, when fastening respective fixing screws on a temperature monitoring and/or control element, the temperature monitoring and/or control element may be lifted from the fixing plate and remain in the air above the hot location. As a consequence, the largest amount of heat in the center of the heating unit cannot be released directly to the temperature monitoring and/or control element, but has to be released via, e.g., the mounting plate, screws, and/or the base plate flange. These effects result in an unacceptable (i.e., too slow) response time of the temperature monitoring and/or control element. Accordingly, it would be advantageous to directly mount a temperature sensor at the position where a certain temperature should be monitored. NTC thermistors are temperature sensors well known in the art. However, the rather inexpensive NTC thermistors may not continuously be exposed to temperatures exceeding 100° C. Since a heating unit of a heating system component usually reaches temperatures above 100° C., inexpensive NTC thermistors are usually not suitable for being directly mounted to or near the heating unit within the heating system component, thus preventing more compact design.
An object of the present invention is therefore to provide a heating system component which avoids the shortcomings of prior-art heating systems.
According to a first aspect of the present invention, there is provided a heating system component for a heating system for heating a fluid medium, said heating system component comprising a carrier unit and a heating unit coupled to said carrier unit. The carrier unit comprises a wet side and a dry side, wherein said wet side corresponds to a surface of said carrier unit configured to be in contact with said fluid medium, wherein said dry side is located on a surface opposite to said wet side; and wherein said heating unit is recessed in a groove provided on said dry side of the carrier unit. The heating system component further comprises at least one temperature sensor, in particular an NTC thermistor, wherein said temperature sensor is effectively in thermal contact with at least a part of an upper surface of said dry side of the carrier unit wherein the part of the upper side of the carrier unit is in contact with said fluid medium at the wet side and wherein the part of the upper side of the carrier unit is effectively thermally insulated from the heating unit.
Being effectively in thermal contact with at least a part of an upper surface of said dry side of the carrier unit does require a direct contact of the temperature sensor with the upper surface of the dry side of the carrier unit. However, the effective thermal contact shall be understood as providing a thermal contact which allows a measurement of the fluid medium circulating at the wet side of the carrier unit. Thus, the thermal contact should ensure a major impact on the measured temperature coming from the fluid medium on the wet side of the carrier unit. The temperature sensor may also measure a mix temperature of the fluid and the heating unit. By providing the temperature sensor, in particular an NTC thermistor, effectively in thermal contact with at least a part of an upper surface of said dry side of the carrier unit, wherein said at least part of the upper side of the carrier unit is effectively thermally insulated from the heating unit, it can be ensured that the temperature sensor is not exposed to temperatures exceeding the maximal temperature of the fluid circulated on the wet side of the carrier unit, which in most common household appliances is 100° C. Within this temperature regime, it is possible to use common cost-effective NTC thermistors which further allow a compact design of the heating system component with reduced material budget.
In an embodiment, said heating system further comprises a heat conducting plate covering at least a part of the groove, wherein the heat conducting plate comprises a detached portion at a circumferential part detached from the heating unit recessed in the groove, the detached portion has a projecting part extending beyond the groove of the carrier unit, the projecting part is in direct contact with the dry side of the carrier unit; and the temperature sensor is mounted at the projecting part, and wherein the detached portion of the heat conducting plate preferably comprises trenches in radial direction of respective peripheral edges of the projecting part. Preferably, the heating system component may further comprise a second temperature sensor, in particular an NTC thermistor, wherein said second temperature sensor is in thermal contact with an upper surface of the heat conducting plate covering the heating unit inside the groove.
In a further embodiment, said heating system component the temperature sensor is provided inside the groove of the carrier unit shielded from the heating unit by a shielding unit. Preferably, the shielding unit is made of stainless steel or aluminum oxide. In a further preferable implementation, a second temperature sensor is provided inside the groove shielded from the heating unit by a shielding unit, wherein the resulting temperature is derived from an average temperature measured by the first and second temperature sensors. In a yet further preferable implementation the first and second temperature sensors are NTC thermistor pills cast in epoxy resin between the dry side of the carrier unit and the shielding unit. The compact, yet cost-efficient design provided by this embodiment allows a reliably measurement of the fluid temperature on the wet side of the carrier unit while providing an easy assemble of the heating system component within a respective household appliance. Since the temperature measurement components are provided inside the groove, the risk of damages during assembly is significantly reduced.
In an embodiment, the heating system component further comprises a heat conducting plate covering at least a part of the groove, wherein the heat conducting plate comprises a projecting part extending beyond the groove of the carrier unit, the projecting part being in direct contact with the dry side of the carrier unit; and wherein the temperature sensor is provided at a ceramic pad fixed at a projection part of the carrier unit. Preferably, a second temperature sensor is positioned on a second ceramic pad, wherein the second ceramic pad is fixed at a position of the heat conduction plate covering the groove. In a further preferable implementation one or more conductor paths are provided along the heat conduction plate to connect the one or more temperature sensors, wherein the conductor paths are insulated from the heat conduction plate by an insulating layer, preferable comprising a polyimide, such as—but not limited to—Kapton, a polyamide or a polyester.
In a further embodiment, the heating system component further comprises a heat conducting plate covering at least a part of the groove, wherein the heat conducting plate comprises a projecting part extending beyond the groove of the carrier unit, the projecting part being in direct contact with the dry side of the carrier unit; wherein at least a part of the heat conducting plate is covered with an insulating layer on top of which the temperature sensor and conductor paths connected to the temperature sensor are formed. Preferably, the heating system component comprises a plug with pins to be connected to the conductor paths wherein the plug also provides electric connections for the heating unit. Preferably, the temperature sensor, the conductor paths and the insulating layer are formed at the heat conducting plate by printing or thermal spraying. Alternatively, the insulating layer may also be attached directly to a portion of the dry side of the carrier unit. Preferably, the temperature sensor and the conductor paths are formed at the insulating layer before being attached to the carrier unit. The insulating layer may be connected to a respective plug and afterwards being glued to the carrier unit, wherein the plug may be welded to the heating unit connection pins and or the carrier unit.
In a further embodiment, the carrier unit comprises an undercut portion which is covered with a thermoplastic layer doped with a metal-plastic additive directly sprayed at the undercut portion and subsequently metalized at respective portions of an upper surface of the thermoplastic layer; wherein the temperature sensor and conductor paths connected to the temperature sensor are formed at the metalized thermoplastic layer by laser cutting. Preferably, the heating system component comprises a transparent plug comprising the electrical contacts to be connected with the conductor paths leading to the temperature sensor wherein the transparent plug is coupled with the thermoplastic layer via laser welding.
In an embodiment, the heating system component further comprises a heat conducting plate covering at least a part of the groove, wherein the heat conducting plate comprises a projecting part extending beyond the groove of the carrier unit, the projecting part being in direct contact with the dry side of the carrier unit; wherein at least a part of the heat conducting plate is covered with a thermoplastic layer doped with a metal-plastic additive directly sprayed at least at a part of the projecting part and subsequently metalized at respective portions of an upper surface of the thermoplastic layer; wherein the temperature sensor and conductor paths connected to the temperature sensor are formed at the metalized thermoplastic layer by laser cutting. Preferably, the heating system component comprises a transparent plug comprising the electrical contacts to be connected with the conductor paths leading to the temperature sensor wherein the transparent plug is coupled with the thermoplastic layer via laser welding.
It shall be understood that a preferred embodiment of the invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
In the following drawings:
Heating system component 100 may be connected to, e.g., a conveyor pump of a domestic appliance such as—but not limited to—a dishwashing machine. Heating system component 100 can be attached to the conveyor pump or to a conveyor pump housing during assembly of the domestic appliance. In another example, heating system component 100 can form a pre-assembled structural unit together with the conveyor pump.
As can be seen from
Heating unit 120 is arranged on the dry side 102 of carrier unit 110 as shown in
Carrier unit 110 may comprise a composite material. The composite material comprises at least an aluminum layer and a stainless steel layer. The stainless steel layer is arranged on the wet side 101 of carrier unit 110. The aluminum layer is arranged on the dry side 102 of carrier unit 110. In an example, the composite material may be produced by means of a cold roll bonding process.
In the embodiment illustrated in
In the embodiment illustrated in
Another possibility for addressing problems associated with an occurrence of voids between carrier unit 110 and heating unit 120 is to arrange a phase change compound between carrier unit 110 and heating unit 120. Such a compound changes its phase state above its phase change temperature and is thereby able to fill cracks, voids, slits, etc. In an embodiment, the phase change compound is applied to the surfaces of carrier unit 110 and/or heating unit 120 by means of a dispensing step. Dispensing typically implies that the phase change compound dries within a short period of time.
In the embodiment illustrated in
Optionally, a second NCT thermistors may be provided, either at a further detached portion 142 in order to determine the fluid temperature, such that the first and second NTC thermistor measurements can be averaged in order to increase the liability. Alternatively, the second NTC thermistor 170b may be mounted at the non-detached portion 144 of the heat conducting plate 140 in order to determine the temperature of the heating unit 120 itself for preventing for instance that the pump is running dry. In the latter case, an NTC thermistor sustaining the resulting temperatures reachable by the heating unit must be chosen.
In the embodiment schematically illustrated in
The embodiment schematically illustrated in
An example application of the invention generally relates to situations where a fluid medium needs to be heated in an efficient manner, for example in household appliances such as dishwashers, dryers, and washing machines, small electrical appliances such as coffeemakers, irons, steam generators etc. or in water heaters. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality.
A single unit or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Determinations like measuring a temperature performed by one or several units or devices can be performed by any other number of units or devices. For example, measuring a temperature can be performed by a single temperature sensor or by any other number of different units. The determinations and/or the control of the heating system for heating fluid media can be implemented as program code means of a computer program and/or as dedicated hardware.
A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium, supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. The term “computer program” may also refer to embedded software.
Any reference signs in the claims should not be construed as limiting the scope.
Number | Date | Country | Kind |
---|---|---|---|
16175278 | Jun 2016 | EP | regional |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/EP2017/065051 | 6/20/2017 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2017/220554 | 12/28/2017 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1418011 | Mehn | May 1922 | A |
1838680 | Hudson | Dec 1931 | A |
2420175 | Johnstone | May 1947 | A |
3782456 | Gusmer | Jan 1974 | A |
4255646 | Dragoy | Mar 1981 | A |
4356381 | Flaherty, Jr. | Oct 1982 | A |
4460819 | Eugster | Jul 1984 | A |
4558205 | Bleckmann | Dec 1985 | A |
4778977 | Bleckman | Oct 1988 | A |
4825042 | Hauslein | Apr 1989 | A |
4992690 | Baker | Feb 1991 | A |
6442341 | Wu | Aug 2002 | B1 |
7293958 | Kraffzik | Nov 2007 | B2 |
7455065 | Schrott | Nov 2008 | B2 |
7538301 | Teufl | May 2009 | B2 |
7560672 | Pleschinger | Jul 2009 | B2 |
9371841 | Verma | Jun 2016 | B2 |
9631835 | De Mango | Apr 2017 | B2 |
10641521 | Wedam | May 2020 | B2 |
10724547 | Zoppas | Jul 2020 | B2 |
20040026411 | Mucke | Feb 2004 | A1 |
20070012685 | Gourand | Jan 2007 | A1 |
20070228032 | Reiter | Oct 2007 | A1 |
20080283094 | Nagel | Nov 2008 | A1 |
20090135882 | Kloíber et al. | May 2009 | A1 |
20100119360 | Bredl | May 2010 | A1 |
20100126534 | Busing | May 2010 | A1 |
20130055902 | Berto | Mar 2013 | A1 |
20130202279 | Reichl | Aug 2013 | A1 |
20150233573 | Ke | Aug 2015 | A1 |
20160109152 | Teufl | Apr 2016 | A1 |
20190335540 | Hofer | Oct 2019 | A1 |
20210145208 | Zhang | May 2021 | A1 |
Number | Date | Country |
---|---|---|
102297506 | Dec 2011 | CN |
102297506 | Apr 2013 | CN |
203478587 | Mar 2014 | CN |
102012013347 | Jan 2014 | DE |
1152639 | Nov 2001 | EP |
2905534 | Dec 2015 | EP |
Entry |
---|
EPO; Application No. PCT/EP2017/065051; International Search Report dated Sep. 4, 2017. |
EPO; Application No. 19165000.1; Extended European Search Report dated Jun. 27, 2019. |
KIPO; Application No. 10-2019-7000347; Office Action dated Jul. 19, 2021. |
Number | Date | Country | |
---|---|---|---|
20190346175 A1 | Nov 2019 | US |