Patent Application
20250151174
Infrared (IR) thermal radiation may transfer and distribute energy more efficiently and effectively compared to thermal conduction and convection. For example, IR thermal radiation can efficiently and effectively spread within a space and become at least partly absorbed by any object in the space. Additionally, air only slightly absorbs infrared radiation, although water vapor absorbs near IR radiation. As such, the objects within the space can increase in temperature before the air within the space increases in temperature. Especially IR-radiation having wavelength between 8-13 dm, or 16-25 dm (atmospheric window) is not absorbed by normal air including carbon dioxide and water vapor. Cellulose, and some related materials emit radiation in this window (Xinxian Yu, Chun Chen, A Simulation study comparing the cooling performance of different daytime radiative cooling materials, Solar Energy Materials and Solar Cells, 209, 2020, Article 110459).
Infrared thermal radiation can be particularly desirable for heating since human skin can efficiently and effectively absorb IR thermal radiation. Therefore, human skin can allow a person to efficiently experience a warmer sensation compared to surrounding temperatures. This can allow room temperatures to be set lower, e.g., approximately 2-5 degrees Celsius lower, without compromising heating comfort. Infrared heating is generally viewed as energy efficient heating, and some currently available IR heaters have provided a cost and/or energy savings of at least 30 percent compared to some other conventional heating methods.
In addition to providing warm sensation, IR may penetrate quite deep (about 2 cm) into a tissue without any observable harmful effects, or overdue heating of the tissue. Actually, the effects of the far IR have been extensively studied. Review articles Fatma Vatansever and Michael R. Hamblin, “Far infrared radiation (FIR): its biological effects and medical applications”, Photonics Lasers Med. 2012 Nov. 1; 4:255-266, R. Shemilt, et al., “Potential mechanisms for the effects of far infrared on the cardiovascular system—a review”, Vasa, 2019 July; 48 (4): 303-312, Tsagkaris, Christos et al. (2022) “Infrared Radiation in the Management of Musculoskeletal Conditions and Chronic Pain: A Systematic Review”, European Journal of Investigation in Health, Psychology and Education, 12, 334-343, and Wang Y Et al., “Molecular Mechanism of Far-infrared Therapy and Its Applications in Biomedicine”, Science & Technology Review, 2014, 32 (30): 80-84, provided as a reference in their entirety) summarize multiple studies in the field. Increasing evidence indicates that far IR may improve health of the patients with cardiovascular disease, diabetes, and chronic kidney disease among others. Thus, the present teaching may provide real positive health effects in addition to comfortable sensation.
Some current infrared heating elements operate at high temperature with a surface temperature of 100 degrees Celsius, and require use of at least 110V power sources. For example, the infrared radiation can be produced by metal and other filaments in some infrared heaters at temperatures of 1,000 degrees Celsius or more. Such high surface and internal temperatures require specific safety features and may not be effectively powered by low-voltage power sources, such as batteries, solar panels, and/or wind power.
At least some currently available electric heaters are exclusively accomplished by resistive wires, which involves drawbacks. For example, electric heating of a space may not be uniform because a relatively small area of the space may receive most of the heat from the electric heater. The resistive wires may also operate at high temperatures, and electric heaters may need to be covered with metals to reduce risk of fires, as well as to distribute heat more evenly.
Currently used heating elements are often clumsy and not decorative. Glass, stone, and especially marble, can provide a more desirable surface. However, unless heating temperature is fairly modest, many kinds of stones and marble tend to crack or deform. This applies especially to marble. The present teaching provides lower-temperature heating solution, and can employ decorative heating elements of different shapes and sizes, and solves the cracking and deforming problems associated with high heat of earlier IR heating elements. Thereby the present teaching enables heating objects, which are multidimensional, irregular in shape and size, and not only two-dimensional panels. As an example, a decorative sculpture can be a heating element.
The present teaching can serve as a black body radiator, or near a black body radiator, while many other heaters are gray body heaters. The significantly better emissivity of black body infrared heaters, such as the present teaching, means that the present teaching's surface temperature can be significantly lower. It is 36 degrees Celsius to produce radiative power of 100 watts per m2 at an ambient temperature of 20 degrees Celsius (68 F), while a gray body heater needs to have a surface temperature of 50 degrees Celsius to produce the same amount of radiated power of 100 watts per m2. When the demand of radiated power is increased from 100 watts per m2 to 1,000 watts per m2, the conventional gray body heaters surface temperature would need to be 180 degrees Celsius, while the present black body heater's surface temperature would be 125 degrees Celsius, assuming ambient temperature of 20 degrees Celsius (68 F).
The aspects of the present teaching have generally a low surface temperature between 40-65° C., which permits the use of fabrics and many other materials as heating elements. Many conventional infrared heaters can have a surface temperature of 100° C. or higher, and the filament temperature as high as 1,500° C. to produce desired infrared radiation. Such conventional infrared heaters cannot be operated at low voltage, require specific safety solutions for their use, and cannot be incorporated in fabrics or marble and many other materials, which can crack or deform at higher temperature, or which are flammable. The present teaching permits the use of fabrics, plastics and such other materials of various shapes and sizes as the heating element.
The radiated power density of the present teaching is highest between 5-35 μm. This is the range in which water and other molecules in ambient air and water vapor do not generally absorb infrared radiation. Thereby the present teaching emits infrared radiation at such spectral wavelength, that the radiation penetrates ambient air without impacting and being hindered by the water and other molecules in the air. Therefore, the infrared and thermal radiation becomes strong enough to provide heating to spaces such as rooms, lecture, and industrial halls and car interiors. When in addition to the narrowband infrared radiation the heater, such as the present teaching, can be powered with low voltage power sources like a battery or a solar panel, the infrared heating solution becomes widely applicable to a large number of conditions, where heating is needed, such as locations, which have no or limited access to electricity grid. Currently available battery-powered or low voltage infrared heaters have had limited use, due to the limited strength of the thermal radiation provided by such infrared heaters.
There are specific applications in which infrared thermal radiation is especially desirable, if such infrared radiation can be produced at a low voltage and preferably using batteries and renewable energy sources. Such examples are boats and vehicles and other means of transportation, which are currently heated either by specifically built heaters and heater cores using the heat provided by internal combustion engines. In the case of electric vehicles, the heating is currently done with battery-powered heating, which consumes a significant amount of battery power and capacity, and reduces the range of the electric vehicle by up to 50%. This is a limitation to the usability of electric vehicles in colder climates or in cold weather.
Vehicles, boats, vessels and other means of transportation with conventional internal combustion engines can use battery-powered infrared heating. As an example, conventional solution for parking heating is to heat a vehicle interior by using dedicated gasoline or diesel powered engines and/or heaters, when the vehicle is parked, and prior to driving the vehicle. These fossil fuel based heaters emit harmful gases and particles. The present teaching permits replacement of such heaters with heaters that are more efficient. An additional benefit from the present teaching is the reduction of weight of the heater. This provides additional fuel consumption and energy use benefits to such vehicles, while using the present teaching.
Heat transfer can also be made more efficient with the present teaching, where a liquid such as water is used as a heat transmitting material. The nanocomposite absorbs thermal radiation energy in such lambda range in which the water or other liquid does not. This allows efficient heat absorption of thermal radiation in the water or other liquid, while keeping the good heat transfer properties of the water or other liquid. The heat transfer properties of the properties of the present teaching can thereby be used also for cooling.
In addition to providing space heaters, the present teaching may be used to direct IR directly to a certain part of a body in order to gain some medical benefit. The present teaching describes heaters that are in direct contact with the skin or separated a certain distance.
Aspects of the current subject matter include various aspects of a heating element that emits IR thermal radiation. The following clauses summarize the present teaching:
The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings.
The accompanying drawings, which are incorporated in and constitute a part of this specification, show certain aspects of the subject matter disclosed herein and, together with the description, help explain some of the principles associated with the disclosed implementations. In the drawings,
When practical, similar reference numbers denote similar structures, features, or elements.
Definition: Nanocomposite is a mixture of at least two different nanocomposites A and B, in which the materials interact with each other at a molecular scale so that each nanocomposite molecule A interacts with at least one molecule of B, and vice versa. This is a fundamental difference from many composites, in which both A and B form large homogeneous clusters, and these clusters are mixed without breaking them. An example of conventional composite would be CNT-cellulose composite, in which CNTs are still large clusters, and cellulose is in its fibrous form, i.e., the CNTs are mostly in contact with other CNTs, and cellulose molecules are mostly in contact with other cellulose molecules. In a nanocomposite, each CNT is wrapped with cellulose molecules that are separated from each other. These two kinds of composites have widely different physical properties. The nanocomposite has much better electrical conductivity and IR radiance, both of which are utilized by the present teaching. A first direction is perpendicular, and away from the front surface, but may include other directions that are within about 90° from the perpendicular.
Infrared (IR) heating can have several benefits over other heating methods, such as conventional electric heating. For example, IR thermal radiation can be readily absorbed by human skin. As such, IR heating can be felt more quickly compared to other heating methods. Furthermore, a person being heated with IR thermal radiation can experience greater temperatures compared to surrounding temperatures (e.g., air temperature). Such heating can allow room temperatures to be set at lower temperatures than what may be generally considered as desired indoor temperatures, such as in a home or office. As such, one benefit associated with IR heating includes improved efficiency and potential energy savings since IR heating can allow people occupying a room to be efficiently and effectively heated to a comfortable temperature without having to first heat the air in the heated space.
Other benefits of IR heating may include a reduction in dust and other particle movement in the heated space since IR heating does not heat the air and therefore does not force the movement of heated air in the heated space. Traditional electric heaters may provide a limited amount of IR radiation (e.g., approximately 5% to 15% of the thermal energy). In comparison, IR heating provided by the present heating element may radiate at least approximately 80 percent of thermal energy as IR radiation.
Various aspects of an IR heating element that provides IR heating are described herein. For example, some aspects of the IR panel heating element can include a first panel that is covered in a nanocomposite, such as a second side of the first panel being at least partly covered with the nanocomposite, the first side being the outer side that is in contact the air. The IR heating element may further include a power transmitting element that provides power (e.g., electricity) to the nanocomposite for generating the IR thermal radiation. The IR panel heating element can further include a back panel extending over the nanocomposite such that the nanocomposite is positioned between the first panel and the back panel. The IR heating element may also include an insulating sheet that is a part of the back panel, either in contact with the nanocomposite, or on the backside of the back panel. The back panel can be configured to direct infrared radiation released from the nanocomposite in a first direction by including a reflective layer as a part of the back panel. In addition, the present teaching enables heating elements, which are multidimensional and irregular in shape and size such as sculptures, decorative items, and other multidimensional objects. Various other aspects of the IR heating element are described in detail below. Additionally, various benefits associated with the IR heating elements are also described herein and are within the scope of this disclosure.
In some aspects, the first panel or the object can be made out of stone, plastic, mineral, fabric, glass, and/or other material. In some aspects, the nanocomposite can be applied to at least a part of a second side of the first panel or the object. A second side of the first panel, which opposes the first side, may be uncoated and configured for radiating the IR thermal radiation generated from the nanocomposite. The first panel can have a variety of shapes and sizes, including a variety of thicknesses (e.g., distance between the first side and second side) and shapes. For example, the first panel can have a thickness of approximately 5 mm. However, other thicknesses are within the scope of this disclosure, such as a thickness greater than or less than 5 mm. In some aspects, the first panel or an object can include a glass panel having low iron and metallic content. For example, the glass panel can include an amount of iron and/or metallic materials such that the thermal transmissivity of the glass panel is maximized. In some aspects, the first panel can be tempered glass. In some aspects, the first panel or the object can be made out of a plastic material, a stone material, and/or a fabric. In some aspects, the first panel or the object can include a curved shape and/or various surface features.
The nanocomposite can be conductive and configured to assist with generating the IR thermal radiation. For example, the nanocomposite can include one or more materials, such as graphite and/or carbon nanotubes. Furthermore, the nanocomposite can be formed into a film. In some aspects, the nanocomposite is made by adding graphite and/or carbon nanotubes into a binder to formulate a paint-like product. In some aspects, the nanocomposite is within a liquid and as a liquid, including the nanocomposite molecules in the paint-like product, to adjust the heat absorption and heat transfer ability of such liquid. In some aspects, the nanocomposite can include wrapping graphitic material into a molecular layer of one or more other materials, such as cellulose and/or polysaccharide, which can coat the graphitic material with a hydrophilic layer. When the solvent evaporates, the conductive layers can first be connected and stay connected. Coated polymer particles can coalesce into a uniform coating, and good electrical conductivity and other desired properties can be obtained and maintained.
In some aspects, the nanocomposite can include a conductive paint including one or more of a carbon nanotubes (CNT), polysaccharides, and latex, or similar binders of carbon nanotubes. Dry paint can include a CNT-cellulose nanocomposite that has good electrical conductivity. This CNT cellulose nanocomposite can radiate thermal energy as IR radiation. In CNT-cellulose nanocomposite, each CNT is in contact with at least one cellulose molecule. This is important, because graphitic materials have high symmetry, and consequently their infrared activity is limited. In a nanocomposite the heat generated in the CNTs is effectively transferred to the polysaccharide, such as cellulose that is able to radiate desired IR-radiation. This can allow heat to spread evenly into a space that is being heated. Some stones, ceramics, plastics, fabric, and glass can be used as conduits to permit and emit IR radiation from the heating element. For example, in some aspects, the transmitting material can have a thickness of less than approximately 5 mm or 10 mm or more than one inch. Other size ranges are within the scope of this disclosure.
The nanocomposite can be electrically conductive and the heating element can serve as a black body radiator. Black body radiation can include a wavelength between 5 micrometers and 35 micrometers, such as when the temperature is from approximately 100 degrees Celsius to 20 degrees Celsius. For example, this can be a comfortable temperature range for a person to receive energy. In addition, IR can penetrate air efficiently at such specific wavelengths. In some aspects, the nanocomposite includes a resistance of less than or equal to 100 Ohms/square. In some aspects, the nanocomposite includes a resistance of less than or equal to 10 Ohms/square. In some aspects, the nanocomposite includes a resistance of less than or equal to 1 Ohm/square.
As discussed above, in some aspects, the nanocomposite can include a film and/or paint (e.g., graphitic paint). Thermal radiation created by the nanocomposite can be adjusted by altering the size, thickness, and/or shape of the nanocomposite (e.g., paint and/or film). Additionally, the strength of the thermal radiation created by the nanocomposite can be adjusted by altering the thickness of the paint or film. Furthermore, the direction of the thermal radiation created by the nanocomposite can be adjusted by altering the size and/or shape of the IR heating element. As an example, a curved IR heating element emits IR more widely than a flat heating element. Both the thickness of the paint, the shape and size of the painted surface, and/or the underlying material can be altered and adjusted, such as to achieve desired strength and direction of IR thermal radiation.
In some aspects, the power transmitting element can include an electrical wire. The power transmitting element can be made out of at least one electrically conductive material, such as copper. In some aspects, the power transmitting element can contact and extend from the nanocomposite. Additionally, the power transmitting element can advantageously be in communication with a power source, such as a battery, solar panel, or another power source. As such, the power transmitting element can provide electrical energy to the nanocomposite for assisting with creating IR thermal radiation, as will be discussed further below. One benefit of the IR heating elements described herein includes the ability to power the IR heating elements with a lower voltage, which can be provided by one or more batteries and/or solar panels (or similar lower energy providing sources). Some currently available battery-powered or low voltage infrared heaters can have limited use due to the limited strength of thermal radiation provided by such infrared heaters.
Some infrared heaters can operate at high temperatures and require use of 110V or higher voltage power sources. The high temperature can require specific safety features, and such infrared heating elements may not be directly powered by batteries or solar panels. In contrast, the IR heating elements described herein can be operated at lower voltages, such as from approximately 4 V to 50 V, although higher voltages are possible. For example, heating elements described herein may be operated by using batteries that may be charged, such as when electricity is most economical, or they may be charged or powered using solar or wind power.
The ability to use low voltage power sources may allow the present heating elements to use various power sources, such as solar-power, wind-power, battery-power, and/or power sources that are outside of an electricity grid. For example, 24 V electricity can be obtained directly from batteries, solar panels, or wind turbines, or from batteries that are charged with solar panels. Such batteries may not require an inverter to convert the low voltage into higher voltages, which can reduce energy losses and provide energy savings.
Some currently available infrared heaters may use relatively high voltages of 110 volts or higher and may not be black body infrared heaters. For example, black body heaters can have an emissivity of 1, while grey body emissivity can be 0.5. The improved emissivity of IR heating elements described herein can allow for lower surface temperatures to achieve the same watts of radiative power compared to a gray body heater. This can allow for more efficient heat generation, as well as allow for additional options for placing the IR heating elements. For example, in some aspects of the IR heating elements, the surface temperature can be approximately 40 degrees Celsius to approximately 65 degrees Celsius. The low temperature of the IR heating elements described herein can allow fabrics and other materials to be included in the IR heating elements. This provides for a safe and less costly application for various heating purposes. The low temperature of the present IR heating element aspects can also allow for the use of decorative marble and other natural stones, which can crack or deform in higher temperatures. The surface temperature of the IR heating elements described herein can be low, such as approximately 40-65 degrees Celsius. Conventional infrared heaters can have higher surface temperatures, such as approximately 70-100 degrees Celsius and higher.
In some aspects, the IR heating element can further include at least one insulating sheet that can be applied over or covering the nanocomposite. For example, such insulating sheet can be made out of a plastic material (e.g., UVA, Akalight ECS 385 material) and/or other heat-insulating material.
In some aspects, the heating element can further include a conductive sheet, such as a sheet of aluminum foil, that can intentionally direct IR thermal radiation in a specific direction (e.g., through the first panel). In some aspects, insulating and protective sheets can be applied on both sides of the aluminum foil. In some aspects, a back panel or sheet can be coupled to an end layer of the insulating sheet. For example, the back panel can prevent IR radiation from traveling therethrough. Additionally, the back panel can direct the IR thermal radiation away from the back panel to thereby direct and/or control the direction of IR thermal radiation being emitted from the IR heating element. Various other IR heating element layers and aspects are within the scope of this disclosure.
The IR heating elements described herein are configured to provide IR heating, have a compact configuration, and can be powered at a lower voltage. In some aspects, the IR heating element can be configured such that the IR radiation is delivered at a wavelength such that water and/or other molecules in the air do not absorb or obstruct the IR radiation. This can allow the IR and thermal radiation to be effectively transmitted to and absorbed by objects, including people, instead of the surrounding air. For example, the wavelength of an aspect of the IR heating element can be a range between approximately 5-35 μm, which can include a range in which water molecules in ambient air and water vapor do not absorb such infrared radiation. This can allow thermal radiation to transfer freely to surrounding surfaces, and allow the surrounding surfaces and objects to become more efficient infrared radiators themselves.
In some aspects, methods and devices for heating and for the manufacture of IR heating elements are described. More specifically, an IR heating element can include a thin layer of nanocomposite, such as electrically conducting graphitic material, that is sandwiched between a first layer of glass, stone, plastic, or other material, and a second layer that is plastic and/or heat insulating material. At least one benefit of the IR heating elements described herein include the ability to program the IR heating element to heat a room to a lower temperature compared to typical room temperatures, such as approximately 2-5 degrees Celsius lower, without compromising heating comfort.
In some aspects the IR heating element is incorporated in vehicle interior, objects, and panels, which can be shaped and irregular in size and shape. At least one benefit of the IR heating element is the reduction of battery usage compared with traditional vehicle heating solutions, when the temperature can be programmed to a lower temperature without compromising heating comfort, and when the IR heating can be directed to passengers as opposed to all of the inside space of the vehicle. Another benefit of the IR heating element in vehicles is the extension of battery range in colder temperatures.
In some aspects the nanocomposite can be used as a heat transfer and absorption solution in liquids. Such liquids include the nanocomposite, which as particles or molecules absorb heat more efficiently within the liquid than the liquid itself. Liquids have an intrinsic ability to absorb heat, which impacts their ability to transfer heat, and such heat transfer ability can be adjusted with the use of the nanocomposite. At least one benefit of the heat transfer solution is the ability to shorten the pipe in which the heat transfer liquid occurs. Another benefit of the heat transfer solution is the reduced heat losses, which results from the reduced surface area of the pipe, which transfers the heat. Another benefit of the heat transfer solution is the ability to adjust the heat transfer so that the heat transfer pipe operates as a cooling solution.
For example, the nanocomposite 14 can be made from a graphitic material and a cellulosic material. In some aspects, the graphitic material can include carbon nanotubes and/or functionalized carbon nanotubes. In some aspects, the carbon nanotubes can include single, double, or multiple walled carbon nanotubes and/or functionalized single, double, or multiple walled carbon nanotubes. The nanocomposite can include any of the nanocomposite aspects described herein and can be included in various forms, such as a paint or film.
The IR heating element 10 can further include at least one insulating sheet 16 positioned adjacent to and covering at least a part of the nanocomposite 14. The insulating sheet 16 can be made out of a UV-stable and hydrolytic resistant material. For example, the insulating sheet 16 can be made out of a plastic material.
The IR heating element 10 can also include a sheet of aluminum foil or other metallic and/or material formed as a sheet. Such metallic or conductive sheet can be positioned between two insulating sheets 16′ to thereby adjust the direction of emitted IR thermal radiation. The IR heating element 10 can also include a back sheet 18 positioned adjacent one of the insulating sheets 16′, to insulate electrically conductive films and layers from one another.
Surface resistance of the nanocomposite 14 can be less than 100Ω. The surface resistance can be adjusted, for example, by varying the thickness of the nanocomposite layer. For example, if the surface resistance is approximately 10Ω, then the IR heating element 10 can have a specific heating power independent of the size of the square area of the IR heating element 10. For example, the IR heating element 10 can have a square shape, however, other shapes are within the scope of this disclosure. The IR heating elements can be aligned and combined to form various shapes and configurations.
For example, a plurality of IR heating elements can be aligned to form a rectangle having a long side that is ten times longer compared to the short side. Additionally, the power output can be 2300 W. The size and shape of the IR heating element (including IR heating element configurations where more than one IR heating element are coupled together or positioned adjacent to each other) can be adjusted so that the surface temperature can be maintained at a desired temperature (e.g., the temperature does not get too hot for its surroundings). For example, at least one IR heating element can cover a part of a wall, or even the entire wall or part of an object, or the whole object.
As shown in
Significant amount of the heat may be radiated as IR thermal radiation 103. Although all surfaces can radiate IR radiation, the material of the IR heating element may include a black body radiator, e.g., the IR heating element 101 can radiate a maximum amount of energy as IR radiation. This can enable more efficient and even heating of surrounding objects at a minimum energy loss. Some currently available heating elements heat surrounding air that raises up towards a ceiling, and a significant part of heat can escape before it spreads into other and lower parts of a room. Thus, the present IR heating elements can save heating energy.
An example manufacturing of an aspect of an IR heating element can include painting a granite plate (e.g., having dimensions of approximately 25 mm×400 mm×1600 mm) with a nanocellulose-MWNT-acrylic latex paint (e.g., 2 w/w % MWNT, provided by Xynac Inc., Ohio). Copper or other electrically conductive tape can be attached or sprayed to both sides of the painted surface. A glass plate (e.g., having dimensions of 4 mm×300 mm×100 mm) can be adhered (e.g., glued with superglue, such as acrylonitrile) on the painted surface. Electrical contacts can be attached to the granite plate and/or paint with copper or other conducting tape or wire along the painted surface or film. Additional layers can be added to the IR heating element, such as one or more insulating layers.
For example, as shown in
The thermal radiation of the present teaching and heating element heats opposing concrete walls at a distance of up to 15 feet by several degrees Celsius, and floors, walls and ceilings by 1.5-2.0 degrees Celsius, in 60 minutes or less with a heater that consumes 330 watts or less.
The principal causes for the high efficiency of the present teaching are the thermal efficiency of carbon nanotubes when manipulated as in the present teaching, and the efficient dispersion of carbon nanotubes in the used nanocomposite.
The thermal efficiency of carbon nanotubes is due to their sub-wavelength nanostructure. Carbon nanotubes have a very small diameter of 1-10 nanometers. The emitted heat radiation wavelength is therefore higher than or equal to the diameter of carbon nanotubes. Research suggests that such heat emission is not based on conventional plate heating theory as advanced by Max Planck and Stefan Boltzmann. Instead, the heat emission can be up to 100 times stronger than what the conventional theory of thermal radiation suggests (Golyk et al, Heat radiation from long cylindrical objects, Phys. Rev. E 85, 046603 (2012)).
A major challenge in developing carbon nanotube-based thermal solutions is the manipulation of carbon nanotubes so that they are both dispersed evenly in the nanocomposite, and so that the interfaces of carbon nanotubes with other carbon nanotubes are optimized to eliminate the thermal resistance in the interfaces between carbon nanotubes. The presence of interfaces between individual carbon nanotubes as found widely in nanocomposites, nanoelectronics, and nanodevices severely limits their performance for larger scale applications. Carbon nanotubes have a huge therman resistance, which needs to be solved by modifying the molecular structure of the interfaces between carbon nanotubes. (Zhiping Xu, Markus J. Buehler, Nanoengineering Heat Transfer Performance at Carbon Nanotube Interfaces, September 2009, ACS Nano 3 (9): 2767-75)).
The present teaching uses a nanocomposite, which has solved the above problem and scientific challenges. The present teaching uses a nanocomposite, in which carbon nanotubes are both dispersed evenly in the nanocomposite, and the interfaces of carbon nanotubes with other carbon nanotubes are optimized to eliminate the thermal resistance of the interfaces between carbon nanotubes. The nanocomposite was originally developed by one of the inventors, prof. Jorma Virtanen, and was developed and manipulated by the present inventors for purposes of the present teaching.
The efficiency of the thermal radiation of the present teaching can also be attributed to the medium infrared frequencies emitted. When the emitted frequencies are between 7-13 μm, infrared heat radiation spreads through air practically without restrictions (Ene et. al, Studies in Infrared Radiation Heating for Increasing Thermal Comfort, Sci Bulletin, Automotive Series, no. 24 (2013).
The present teaching can produce such infrared radiation in medium infrared frequencies with a safe heating element, whose surface temperature is 60 degrees Celsius or less. The conventional method has been the use of metal filaments, whose temperature is approx. 1,000 degrees Celsius (Ene et. al, Studies in Infrared Radiation Heating for Increasing Thermal Comfort, Sci Bulletin, Automotive Series, no. 24 (2013). Such traditional infrared heating in midinfrared frequencies uses thus tungsten and other metal compounds. However, their challenge is the high temperature of such core metals, and the resulting high surface temperature of commonly 100 degrees Celsius of the heater itself.
Generally infrared heating is significantly more efficient and approx. 50% or more efficient than electric baseboard or traditional heat pump heating (Dept of Energy, DOE/NAHB Project No. 4159 May 31, 1994). Even higher efficiency gains of 100% from infrared heating in comparison with other heating solutions has been noticed in other studies (Enabling Technologies & Innovation Competences Challenge Project, Project Nr. 01R18PO2312, Oct. 12, 2021, Aston University).
The energy savings of the present teaching are thereby significant, due to infrared radiation alone, compared with electric baseboard heating or traditional heat pumps.
In addition, the present heating can use low voltage power sources, and the above research (Golyk et al) proves that the use of such nanofilm, which is based on carbon nanotubes, can provide heat radiation that is up to 100 times more than the conventional laws of Max Planck and Stefan Boltzmann suggest. The present teaching uses all of these elements to achieve energy savings, which can be 80% compared with conventional central heating.
In the descriptions above and in the claims, phrases such as “at least one of” or “one or more of” may occur followed by a conjunctive list of elements or features. The term “and/or” may also occur in a list of two or more elements or features. Unless otherwise implicitly or explicitly contradicted by the context in which it is used, such a phrase is intended to mean any of the listed elements or features individually or any of the recited elements or features in combination with any of the other recited elements or features. For example, the phrases “at least one of A and B;” “one or more of A and B;” and “A and/or B” are each intended to mean “A alone, B alone, or A and B together.” A similar interpretation is also intended for lists including three or more items. For example, the phrases “at least one of A, B, and C;” “one or more of A, B, and C;” and “A, B, and/or C” are each intended to mean “A alone, B alone, C alone, A and B together, A and C together, Band C together, or A and Band C together.” Use of the term “based on,” above and in the claims is intended to mean, “based at least in part on,” such that an unrecited feature or element is also permissible.
The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail herein, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and/or combinations and sub-combinations of one or more features further to those disclosed herein. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. The scope of the following claims may include other implementations or aspects.
This application is a continuation-in-part of U.S. Ser. No. 18/552,276, filed Sep. 25, 2023, now U.S. Pat. No. 12,200,829, which is a national phase of PCT/US2022/07314, filed Mar. 24, 2022, which claims priority to provisional patent application Ser. No. 63/207,820, filed Mar. 25, 2021, all of which are incorporated herein by reference. The subject matter described herein relates to various methods and aspects of a heating and heat transfer element that emits infrared and thermal radiation, and the manufacture of such heating and infrared radiation elements.
| Number | Date | Country | |
|---|---|---|---|
| 63207820 | Mar 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18552276 | Sep 2023 | US |
| Child | 19020429 | US |
