WO2025167523A1 - Aerosol generating apparatus - Google Patents

Abstract

Provided in the present application is an aerosol generating apparatus, comprising: a heating tube, wherein an insertion port is provided at an upper end of the heating tube, an aerosol generating substrate of an aerosol generating article can be inserted into the heating tube by means of the insertion port, and the heating tube comprises a heat generating layer and a tube body, the heat generating layer covering at least part of a heating area of the tube body, so that the heating tube can heat the aerosol generating substrate; and an induction coil, which surrounds the periphery of the heating tube and is used for generating a changing magnetic field. A susceptor capable of generating heat in the changing magnetic field is further arranged in the aerosol generating apparatus or the aerosol generating article, and is used for heating the aerosol generating substrate from the inside. The aerosol generating apparatus is configured such that the induction coil and the heating tube output energy independently of each other.

Description

Aerosol generating device

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese patent application number 202410163166.9, entitled “Aerosol Generating Device,” filed with the Patent Office of China on February 5, 2024, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates to the technical field of heat-without-combustion aerosol generation, and in particular to an aerosol generating device.

Background Art

Smoking articles (eg, cigarettes, cigars, etc.) burn tobacco during use to produce tobacco smoke. Attempts have been made to replace these tobacco-burning articles by creating products that release compounds without combustion.

Examples of such products are heating devices, which release compounds by heating rather than burning a material. For example, the material may be an aerosol-generating article containing tobacco or other non-tobacco products, which may or may not contain nicotine.

A known heating device includes a central heating element and a circumferential heating element. The central heating element is used to heat the tobacco product from the inside, and the circumferential heating element is used to heat the tobacco product from the outside. The heating device reduces the temperature difference between the center and the surface of the tobacco product by generating heat through the central heating element and the circumferential heating element.

However, in the current heating device, the energy output of the central heating element and the circumferential heating element are linked. If the energy output of one of the central heating element and the circumferential heating element changes, the energy output of the other also changes. As a result, the heating of the tobacco product cannot meet the user's demand for a higher experience of the tobacco product.

Application Contents

The present application provides an aerosol generating device, whose induction coil and heating tube can output energy independently of each other, meeting the user's higher-level experience requirements.

One aspect of the present application provides an aerosol generating device comprising:

a heating tube having an insertion opening through which an aerosol-generating substrate of an aerosol-generating article can be inserted, the heating tube comprising a heat-generating layer and a tube substrate, the heat-generating layer covering at least a portion of a heating zone of the tube substrate so that the heating tube can heat the aerosol-generating substrate; and

an induction coil, surrounding the periphery of the heating tube, for generating a changing magnetic field;

The aerosol generating device or the aerosol generating article is further provided with a susceptor capable of generating heat in a changing magnetic field, the susceptor being used to heat the aerosol generating substrate from the inside;

Wherein, the aerosol generating device is configured so that the induction coil and the heating tube output energy independently of each other.

Another aspect of the present application provides an aerosol generating device comprising:

a heating tube capable of accommodating at least an aerosol-generating substrate of the aerosol-generating article, the heating tube comprising a heat-generating layer; and

an induction coil, surrounding the periphery of the heating tube, for generating a changing magnetic field;

The aerosol generating device or the aerosol generating article is further provided with a susceptor capable of generating heat in a changing magnetic field, and the susceptor is used to heat the aerosol generating substrate from the inside;

The aerosol generating device is configured such that, in the changing magnetic field provided by the induction coil, the conversion efficiency of the heating layer to electromagnetic energy is no higher than 30%.

The above-mentioned aerosol generating device includes a heating tube and an induction coil surrounding the periphery of the heating tube. The induction coil is used to generate a changing magnetic field. The aerosol generating matrix of the aerosol generating product can be inserted into the heating tube. The heating tube includes a heating layer and a tube substrate having a heating area. The heating layer covers at least a part of the heating area of the tube substrate, so that the heating tube can heat the aerosol generating matrix. The sensor in the aerosol generating device or the aerosol generating product can heat the aerosol generating matrix from the inside under a changing magnetic field. The aerosol generating device is configured so that the induction coil and the heating tube output energy independently of each other, so that the induction coil and the heating tube have independent energy output strategies, thereby being able to meet the user's higher-level experience requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

FIG1 is a schematic diagram of an aerosol generating device provided in one embodiment of the present application;

FIG2 is a partial cross-sectional view of an aerosol generating device provided in one embodiment of the present application;

FIG3 is a schematic diagram of a combination of a heating tube and an induction coil provided in one embodiment of the present application;

FIG4 is an exploded schematic diagram of a heating tube and an induction coil provided in one embodiment of the present application;

FIG5 is a schematic diagram of a heating tube provided in one embodiment of the present application;

FIG6 is a schematic diagram of a heating tube provided in another embodiment of the present application;

FIG7 is a schematic diagram of a heating tube provided in yet another embodiment of the present application;

FIG8 is a schematic diagram showing the positional relationship between the heating tube and the induction coil assembly provided in one embodiment of the present application;

FIG9 is a schematic diagram showing the positional relationship between a heating tube and an induction coil assembly provided in another embodiment of the present application;

FIG10 is a schematic diagram showing the positional relationship between a heating tube and an induction coil assembly according to another embodiment of the present application;

In the picture:
1. Aerosol-generating product; 11. Aerosol-forming substrate;
2. Power supply assembly; 21. Power supply; 22. Circuit board;
3. Heating tube; 31. Insertion port; 32. Heating layer; 33. Tube base; 34. Electrode layer;
35. Fast rising zone; 36. Slow rising zone;
4. Induction coil;
5. Receptor;
6. Thermal insulation layer.

DETAILED DESCRIPTION

The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiment is only a regional embodiment of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

The terms "first", "second" and "third" in this application are only used for descriptive purposes and cannot be understood as indicating or suggesting relative importance or implicitly indicating the quantity or order of the indicated technical features. In the embodiments of the present application, all directional indications (such as up, down, left, right, front, back ...) are only used to explain the relative position relationship or movement situation between the various components under a certain posture (as shown in the accompanying drawings). If the posture changes, the directional indication also changes accordingly. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or equipment comprising a series of steps or units is not limited to the steps or units listed, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or equipment.

References to "embodiments" herein mean that the features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be one or more intermediate elements in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

With reference to FIG. 1 , one embodiment of the present application provides an aerosol generating device, which is a device that engages or interacts with an aerosol generating article 1 to form an inhalable aerosol.

As used herein, the term "aerosol-generating article" refers to an article comprising an aerosol-forming substrate 11 that, when heated, releases volatile aerosol-forming compounds to form an aerosol. In some embodiments, the aerosol-generating article 1 is removably coupled to an aerosol-generating device. The aerosol-generating article 1 may be disposable or reusable.

The aerosol-forming substrate 11 may comprise a solid aerosol-forming substrate. The solid aerosol-forming substrate may comprise a tobacco-containing material containing volatile tobacco flavour compounds that are released from the aerosol-forming substrate upon heating. The solid aerosol-forming substrate may comprise a non-tobacco material. The solid aerosol-forming substrate may comprise a tobacco-containing material as well as a non-tobacco material.

Aerosol forming matrix 11 can comprise liquid aerosol forming matrix. Liquid aerosol forming matrix can comprise liquid containing tobacco material containing volatile tobacco flavor components, can also be the liquid comprising non-tobacco material. Liquid aerosol forming matrix can comprise water, solvent, ethanol, plant extract, spices, flavoring agent or vitamin mixture etc., spices can comprise betel nut extract, menthol, peppermint, spearmint oil, various fruity fragrance components etc., but is not limited to this. Flavoring agent can comprise the component that can provide various fragrance or local flavor to the user. Vitamin mixture can be the mixture that is mixed with at least one of vitamin A, vitamin B, vitamin C and vitamin E, but is not limited to this.

The aerosol generating device may be an electrically operated device comprising a power supply assembly 2 and a heating assembly.

The power supply assembly 2 includes a power supply 21 and a circuit board 22. The power supply 21 can include any suitable battery or battery cell. The circuit board 22 has one or more controllers. The one or more controllers can control the power output of the power supply 21, such as controlling the sensory prompter in the aerosol generating device to generate sensory signals such as sound, light or vibration, or controlling other operations of the aerosol generating device.

Based on the power output by the power supply assembly 2, the heating assembly releases heat to heat the aerosol-forming substrate 11, causing the aerosol-forming substrate 11 to generate aerosol. The circuit board 22 controls the power output by the power supply 21, thereby controlling the temperature and rate at which the heating assembly heats the aerosol-forming substrate 11. The circuit board 22 controls the power output by the power supply 21, thereby controlling the temperature and rate at which the heating assembly heats the aerosol-forming substrate 11. The circuit board 22 controls the power output from the power supply 21, thereby operating various components.

Referring to Figures 1 and 2 , the heating assembly includes a heating tube 3, which is capable of generating heat based on the power provided by the power supply assembly 2 and outputting thermal energy. When the aerosol-generating article 1 is coupled to the aerosol-generating device, at least a portion of the aerosol-generating article 1 is located within the heating tube 3. For example, at least a portion of the aerosol-forming substrate 11 is located within the heating tube 3. The heating tube 3 is configured to heat the aerosol-forming substrate 11 from the outside. Specifically, the upper end of the heating tube 3 is open, forming an insertion opening 31, through which at least a portion of the aerosol-forming substrate 11 is inserted into the heating tube 3.

In some embodiments, referring to FIG. 3 and FIG. 4 , the heating tube 3 includes a tube base 33 and a heating layer 32 disposed on the tube base 33 . The tube base 33 is used to hold the heating layer 32 .

The heating layer 32 may include a resistive material so that Joule heat can be generated when current flows through it. Suitable resistive materials include, but are not limited to, semiconductors such as doped ceramics, conductive ceramics (e.g., molybdenum disilicide), carbon, graphite, metals, metal alloys, and composite materials made of ceramic materials and metal materials. Such composite materials may include doped or undoped ceramics. Examples of suitable doped ceramics include doped silicon carbide. Examples of suitable metals include titanium, zirconium, tantalum, and platinum group metals. Examples of suitable metal alloys include stainless steel, Constantan, nickel-containing alloys, cobalt-containing alloys, chromium-containing alloys, aluminum-containing alloys, titanium-containing alloys, zirconium-containing alloys, hafnium-containing alloys, niobium-containing alloys, molybdenum-containing alloys, tantalum-containing alloys, tungsten-containing alloys, tin-containing alloys, gallium-containing alloys, manganese-containing alloys, and iron-containing alloys, as well as superalloys based on nickel, iron, and cobalt, stainless steel, iron-aluminum-based alloys, and iron-manganese-aluminum-based alloys.

The heating layer 32 may comprise an infrared radiation material that, when excited, generates infrared radiation of a certain wavelength, for example, infrared radiation in the range of 0.75 μm to 1000 μm. In some embodiments, the infrared radiation includes far-infrared radiation in the range of 1.5 μm to 400 μm, or far-infrared radiation in the range of 8 μm to 15 μm. When the wavelength of the infrared radiation matches the wavelength required to be absorbed by a component in the aerosol-forming substrate 11, the energy of the infrared radiation is easily absorbed by the component in the aerosol-forming substrate 11. The infrared radiation material can be prepared by mixing tin tetrachloride, tin oxide, antimony trichloride, titanium tetrachloride, and anhydrous copper sulfate in a certain proportion and then coating the mixture on the surface of the tube substrate 33. Alternatively, the infrared radiation material can include one of a silicon carbide ceramic layer, a carbon fiber composite layer, a zirconium-titanium oxide ceramic layer, a zirconium-titanium nitride ceramic layer, a zirconium-titanium boride ceramic layer, a zirconium-titanium carbide ceramic layer, an iron oxide ceramic layer, an iron nitride ceramic layer, an iron boride ceramic layer, an iron carbide ceramic layer, a rare earth oxide ceramic layer, a rare earth nitride ceramic layer, a rare earth boride ceramic layer, a rare earth carbide ceramic layer, a nickel-cobalt oxide ceramic layer, a nickel-cobalt nitride ceramic layer, a nickel-cobalt boride ceramic layer, a nickel-cobalt carbide ceramic layer, or a high-silicon molecular sieve ceramic layer. The infrared radiation material can be prepared by thoroughly mixing far-infrared electrothermal ink, ceramic powder, and an inorganic binder, then coating the mixture on the surface of the tube substrate 33 and drying and curing the mixture for a certain period of time.

In some embodiments, the heating layer 32 includes an infrared radiation layer, and the thickness of the infrared radiation layer may be no greater than 50 μm, but is not limited thereto. In some embodiments, the infrared radiation layer includes the aforementioned infrared radiation material. In order to excite the infrared radiation material, the heating layer 32 further includes a heating element. The infrared radiation layer is excited by absorbing the heat released by the heating element and radiates infrared rays. In this embodiment, the heating element included in the heating layer 32 may be a resistive heating element that can generate Joule heat when current flows through it. In some embodiments, the infrared radiation layer includes both a resistive material and an infrared radiation material. The resistive material and the infrared radiation material are mixed to form a slurry or coating. The slurry or coating is disposed on the tube substrate 31 to form an infrared radiation layer. The infrared radiation layer can form a conductive circuit with the power supply component, so that the infrared radiation layer can both generate Joule heat and radiate at least part of the Joule heat to the aerosol generating substrate 11 in the form of infrared rays.

Furthermore, the heat generating layer 32 or the infrared radiation layer has a resistance of not less than 0.8Ω. The heat generating layer 32 or the infrared radiation layer may also have a resistance of not less than 1.2Ω, 1.5Ω, 2.3Ω or 4Ω.

In some embodiments, the heating layer 32 is disposed on the surface of the tube substrate 33 by spraying, printing, chemical deposition, physical deposition, ion implantation, particle sputtering, or vacuum evaporation. In this regard, referring to FIG5 , the heating assembly may further include an electrode layer 34. The electrode layer 34 may be disposed on the surface of the tube substrate 33 or on the heating layer 32 by spraying, printing, chemical deposition, physical deposition, ion implantation, particle sputtering, or vacuum evaporation, and is electrically connected to the heating layer 32. The resistivity of the electrode layer 34 is much lower than that of the heating layer 32. The heating layer 32 is electrically connected to the power supply assembly 2 via the electrode layer 34.

Referring to Figure 1 , the heating assembly includes a magnetic field generator electrically connected to a power supply assembly 2 . The magnetic field generator generates a varying magnetic field based on the varying current supplied by the power supply assembly 2 , and outputs electromagnetic energy. The varying magnetic field generated by the induction coil 4 generates heat in the susceptor 5 .

In some embodiments, the magnetic field generator includes an induction coil 4. The induction coil 4 can be formed into a spiral shape by winding a conductive wire. In the embodiments shown in Figures 1 and 2, the induction coil 4 is a densely wound spiral, with adjacent turns of the coil close together. It should be noted that in other embodiments, the induction coil 4 is a sparsely wound spiral, with adjacent turns of the coil spaced apart, or in other embodiments, the induction coil 4 is a coil with uneven winding density.

The conductor wound around the induction coil 4 may be a round wire, ie, the cross section of the conductor is approximately circular. The conductor wound around the induction coil 4 may be a flat wire, ie, the cross section of the conductor is approximately rectangular.

In some embodiments, the heating assembly includes a susceptor 5, at least a portion of which extends in the heating tube 3, so that when the aerosol-generating article 1 is engaged with the heating tube 3, at least a portion of the susceptor 5 can be inserted into the interior of the aerosol-generating article 1 and heat the aerosol-forming substrate 11 therein.

It should be noted that, as used herein, the term "susceptor" refers to a material that can convert electromagnetic energy into heat. When placed within a changing electromagnetic field, eddy currents and/or magnetic hysteresis induced in the susceptor 5 cause the susceptor 5 to generate heat. The susceptor 5 can be in the form of a sheet, rod, needle, or tube; the specific shape of the susceptor 5 is not limited in this application.

In some embodiments, the susceptor 5 may comprise a receptive material, for example, a metal or carbon. In some embodiments, the receptive material may comprise a ferromagnetic material, such as at least one of ferrite, ferromagnetic steel, or stainless steel. In some embodiments, the receptive material comprises at least one of a nickel-iron alloy or a permalloy. In some embodiments, the receptive material comprises 400 series stainless steel, including 410, 420, or 430 grade stainless steel, among others.

In embodiments where the heating assembly includes a susceptor 5, when at least a portion of the susceptor 5 is inserted into the aerosol-generating article 1, the end of the susceptor 5 may be located in the aerosol-generating substrate 11 and spaced from the downstream end of the aerosol-generating substrate 11, or the end of the susceptor 5 may be flush with the downstream end of the aerosol-generating substrate 11, or the end of the susceptor 5 may pass through the aerosol-generating substrate 11.

In some embodiments, the aerosol-generating article 1 adapted for use with the aerosol-generating device includes a susceptor 5, i.e., the susceptor 5 is an integral component of the aerosol-generating article 1. In this embodiment, at least a portion of the susceptor 5 is disposed within the aerosol-generating substrate 11. The length of the susceptor 5 may be greater than or equal to the length of the aerosol-generating substrate 11, or may be less than the length of the aerosol-generating substrate 11. The susceptor 5 may be closer to the downstream end of the aerosol-generating substrate 11. The susceptor 5 may be closer to the upstream end of the aerosol-generating substrate 11. The susceptor 5 may be located between the upstream and downstream ends of the aerosol-generating substrate 11, and may be equidistant from the upstream and downstream ends of the aerosol-generating substrate 11.

It should be noted that at least one of the aerosol generating device and the aerosol generating product 1 only needs to include the receptor 5 .

In the aerosol generating device provided in some embodiments of the present application, the induction coil 4 and the heating tube 3 are configured to output energy independently of each other. Changes in the energy output of one of the induction coil 4 and the heating tube 3 do not affect the energy output of the other. The other can continue to maintain the original energy output state, or the energy output per unit time of the other can increase or decrease, but the increase or decrease is independent.

Based on this, in some embodiments where the aerosol generating device does not have a susceptor 5 , the aerosol generating device can heat aerosol-generating products 1 with susceptors 5 and can also heat aerosol-generating products 1 without susceptors 5 .

When the aerosol generating product 1 connected to the aerosol generating device does not have the sensor 5, the heating layer 32 is electrically connected to the power supply component 2, and the aerosol generating device can use the heating tube 3 to heat the aerosol generating matrix 11 of the aerosol generating product 1. The power supply component 2 can be controlled to disconnect the electrical connection between the magnetic field generator or the induction coil 4, so as to be unable to provide power for the magnetic field generator or the induction coil 4 to output electromagnetic energy, or the power supply component 2 can be controlled to prohibit providing power to the magnetic field generator or the induction coil 4.

When the aerosol-generating article 1 coupled to the aerosol-generating device includes a susceptor 5, the heat-generating layer 32 is electrically connected to the power supply assembly 2, and the magnetic field generator or induction coil 4 is also electrically connected to the power supply assembly 2. The heat-generating layer 32 can generate heat by converting the electricity provided by the power supply assembly 2, thereby externally heating the aerosol-generating article 1. The susceptor 5 can generate heat by converting the electromagnetic energy provided by the magnetic field generator or induction coil 4, thereby internally heating the aerosol-generating article 1.

When the heating layer 32 on the heating tube 3 comprises a receptive material or a receptive heating element and also comprises a resistive material or an infrared radiation layer, but the aerosol-generating article 1 coupled to the aerosol-generating device does not include a receptor 5, the heating layer 32 is electrically connected to the power supply assembly 2, and the magnetic field generator or induction coil 4 may also be electrically connected to the power supply assembly 2. The heating layer 32 can convert the electricity directly provided by the power supply assembly 2 into thermal energy, and can also convert at least a portion of the electromagnetic energy generated by the magnetic field generator or induction coil 4 in response to the power provided by the power supply assembly 2 into thermal energy. This means that the heating layer 32 generates a portion of its thermal energy from its conversion of the power provided by the power supply assembly 2, and a portion of its thermal energy from its conversion of the electromagnetic energy provided by the magnetic field generator or induction coil 4.

Therefore, when the aerosol generating device does not include the sensor 5, the aerosol generating device provided in the present application, which has both the heating tube 3 and the magnetic field heater, can heat both the aerosol generating product 1 with the sensor 5 and the aerosol generating product 1 without the sensor 5, because the induction coil 4 and the heating tube 3 are configured to output energy independently of each other.

When the susceptor 5 is part of the aerosol generating device, the heating layer 32 is electrically connected to the power supply assembly 2, and the magnetic field generator or induction coil 4 is also electrically connected to the power supply assembly 2. The heating layer 32 can generate heat primarily by converting electricity provided by the power supply assembly 2, while the susceptor 5 can generate heat primarily through electromagnetic energy provided by the magnetic field generator or induction coil 4. Furthermore, because the induction coil 4 and the heating tube 3 are configured to output energy independently, their operation can be independently controlled.

Based on this, in some embodiments, the controller first controls the induction coil 4 to work so that the induction coil 4 outputs electromagnetic energy, and then controls the heating tube 3 to work so that the heating tube 3 outputs heat energy.

Specifically, in some embodiments, the aerosol-generating device's heating of the aerosol-generating article 1 includes a preheating phase and a puffing phase. The preheating phase is used to rapidly heat the aerosol-generating article 1 from an initial temperature or room temperature to a first preset temperature, so that the aerosol-generating article 1 quickly provides the user with a first aerosol for inhalation. The user's inhalation of the aerosol-generating article 1 primarily occurs during the puffing phase, and the temperature during the inhalation phase generally needs to be maintained within a second preset temperature range, which is lower than the first preset temperature.

Since the heating tube 3 is relatively heavy, power consumption is high and heating is slow, and it takes a long time to heat the aerosol generating product 1 from the initial temperature or room temperature to the first preset temperature. Moreover, since the heating tube 3 has a relatively large heating area for the aerosol generating product 1, more water vapor is baked out of the aerosol generating product 1, which easily makes the temperature of the first few puffs of aerosol high, and it is easy to burn the mouth.

The receptor 5 is a low-power, high-efficiency heating element that rapidly heats up under the influence of electromagnetic energy, helping the aerosol-generating article 1 quickly produce the first puff of aerosol that meets the user's needs. Furthermore, the receptor 5 has a small heating area for the aerosol-generating article 1, which reduces the amount of water vapor released from the aerosol-generating article 1. This effectively reduces the temperature of the first few puffs of aerosol, thereby preventing mouth burns.

Therefore, the induction coil 4 and the heating tube 3 can output energy independently of each other. During the preheating stage, the induction coil 4 can be controlled to output electromagnetic energy, causing the sensor 5 to heat up, thereby quickly generating the first aerosol and preventing the first aerosol from being too hot and burning the mouth.

Since the temperature of the sensor 5 is high and the heating area of the aerosol-generating product 1 is small, it is easy to cause uneven heating of the aerosol-generating product 1, which not only makes the aerosol-forming matrix 11 unable to be fully utilized, but also causes local areas of the aerosol-forming matrix 11 to produce harmful substances due to excessive temperature.

The heating tube 3 has a relatively large heating area for the aerosol-generating product 1, which can fully bake the aerosol-forming substrate 11, thereby helping to fully utilize the aerosol-forming substrate 11 and prevent the aerosol-forming substrate 11 from generating harmful substances.

Therefore, in some embodiments, the induction coil 4 and the heating tube 3 can output energy independently of each other. During the inhalation stage, the power supply component 2 is controlled to stop providing power to the induction coil 4, and at the same time, the power supply component 2 is controlled to provide power to the heating layer 32 on the heating tube 3, so that the heating tube 3 heats the aerosol generating product 1.

Alternatively, in some embodiments, during the inhalation phase, the power supply component 2 is controlled to reduce the power provided by the power supply component 2 to the induction coil 4 to reduce the heating temperature of the sensor 5, and at the same time, the power supply component 2 is controlled to provide power to the heating layer 32 on the heating tube 3, so that the heating tube 3 heats the aerosol generating product 1.

Alternatively, in some embodiments, during the preheating phase, the susceptor 5 primarily heats the aerosol-generating article 1, with the heating tube 3 providing a supplementary heating function. During the inhalation phase, the susceptor 5 provides a supplementary heating function, with the heating tube 3 providing the primary heating function. For example, during the preheating phase, the power supply assembly 2 is controlled to simultaneously supply power to the induction coil 4 and the heating tube 3, but the amount of heat released per unit time by the susceptor 5 is greater than that released by the heating tube 3. During the inhalation phase, the power supply assembly 2 is controlled to continue to simultaneously supply power to the induction coil 4 and the heating tube 3. Compared to the preheating phase, during the inhalation phase, the power supplied by the power supply assembly 2 to the induction coil 4 is reduced, causing the temperature of the susceptor 5 to decrease. During the inhalation phase, the power supplied by the power supply assembly 2 to the heating tube 3 is increased, causing the temperature of the heating tube 3 to increase. This allows the temperature of the heating tube 3 to be approximately the same as the temperature of the susceptor 5, or to be slightly higher than the temperature of the susceptor 5, thereby achieving a uniform temperature distribution from the surface to the center of the aerosol-forming substrate 11.

In some embodiments, part of the heating zone of the tube substrate 33 is a fast-rising zone 35 , and part of the heating zone is a slow-rising zone 36 , wherein the heating rate of the fast-rising zone 35 is greater than the heating rate of the slow-rising zone 36 .

By having at least two heating zones of the tube base 33 have different heating rates, the aerosol-generating matrix 11 is heated in a layered manner, allowing the aerosol-generating matrix 11 to release aerosol in a layered manner. This helps the same and/or different components in the aerosol-generating matrix 11 volatilize at different temperatures, thereby enriching the flavor of the aerosol and providing the user with a better mouthfeel. Furthermore, the release amount of the aerosol-generating matrix 11 can be balanced by reducing the amount of aerosol released in the early stages and increasing the amount of aerosol released in the later stages, thereby ensuring consistency in each puff and extending the time the aerosol-generating matrix 11 releases aerosol, thereby improving the user experience.

Because the slow-rise zone 36 heats up at a slower rate than the fast-rise zone 35, at least during the initial stages of operation of the heating tube 33, the temperature of the slow-rise zone 36 is lower than that of the fast-rise zone 35. As the fast-rise zone 35 heats up, the temperature of the slow-rise zone 36 also rises. One reason for the temperature increase in the slow-rise zone 36 may be that the tube substrate 33 in the slow-rise zone 36 absorbs some of the heat from the tube substrate 33 in the fast-rise zone 35. Ultimately, the temperature of the slow-rise zone 36 reaches a dynamic equilibrium with that of the fast-rise zone 35.

In some embodiments, the temperature of the slow rise zone 36 can eventually be substantially equal to the temperature of the fast rise zone 35 , but the present invention is not limited thereto.

In some embodiments, during the process of heating the aerosol-generating product 1 by the heating tube 33, at least in one time period, the slow-rise zone 36 can heat the corresponding aerosol-generating product 1 by releasing at least part of the heat absorbed from the fast-rise zone 35; the heating of the aerosol-generating product 1 by the slow-rise zone 36 can be: preheating the corresponding aerosol-generating substrate 11 in the early stage, and smoke-baking the corresponding aerosol-generating substrate 11 in the middle and/or late stages, that is, in the middle and/or late stages, the heat provided by the slow-rise zone 36 to the aerosol-generating substrate 11 can cause at least one component in the aerosol-generating substrate 11 to volatilize and generate an aerosol.

It should be noted that the heating zone of the tube base 33 is the area of the tube base 33 primarily used for heating the aerosol-generating article 1 or the aerosol-generating substrate 11. In some embodiments, the heating zone may include an infrared-transmissive area, or may be a region of the tube base 33 corresponding to the aerosol-generating substrate 11. The fast-rise zone 35 and slow-rise zone 36 on the tube base 33 are both part of the heating zone. The upper and lower ends of the tube base 33 are primarily used for assembly, rather than for heating the aerosol-generating article 1. Therefore, in this application, even if the assembly areas at the upper and lower ends of the tube base 33 are not covered by the heating layer 32, they are still not considered slow-rise zones.

In some embodiments, along the axial direction of the heating tube 3, the area up to 3 mm downward from the upper end surface of the tube base 33 is the assembly area of the upper end of the tube base 33, and the area up to 3 mm upward from the lower end surface of the tube base 33 is the assembly area of the lower end of the tube base 33.

In some embodiments, a heat-conducting layer is provided on the surface of the tube substrate 33. The heat-conducting layer has a higher thermal conductivity than the tube substrate 33. At least a portion of the heat-generating layer 32 covers a portion of the heat-conducting layer, or a portion of the heat-conducting layer covers at least a portion of the heat-generating layer 32, while the remaining heat-conducting layer constitutes at least a portion of the slow-rise zone 36. The heat-conducting layer can transfer heat from the fast-rise zone 35 to the slow-rise zone 36 more quickly, thereby increasing the heating rate of the slow-rise zone 36. The heat-conducting layer can include a material with high thermal conductivity, such as graphite, graphite alloy, aluminum, or aluminum alloy. It should be emphasized that the heat-conducting layer is optional and not required.

The present application will now describe in more detail the solution for making at least two locations of the tube substrate 33 have different heating rates from at least three aspects.

First, there are one or more heating layers 32, and the total length of the one or more heating layers 32 is shorter than the length of the heating zone of the tube base 33, so that the heating layer 32 does not completely cover the heating zone of the tube base 33. Specifically, the fast-rise zone 35 includes the area of the heating zone covered by the heating layer, and the slow-rise zone 36 includes the area of the heating zone not covered by the heating layer 32. As a result, the temperature rise rate of the fast-rise zone 35 is faster than that of the slow-rise zone 36.

Based on the first aspect, in some embodiments, as shown in FIG5 , a single heating layer 32 is provided, and the heating layer 32 is positioned toward the upper end of the tube base 33, such that the fast-rise zone 35 is located above the slow-rise zone 36. This embodiment facilitates rapid entry of the aerosol generated by the aerosol-generating substrate 11 into the mouthpiece of the aerosol-generating article 1, facilitating a quick inhalation of the first aerosol. In some embodiments, as shown in FIG6 , a single heating layer 32 is provided, and the heating layer 32 is positioned toward the lower end of the tube base 33, such that the fast-rise zone 35 is located below the slow-rise zone 36. This embodiment facilitates lowering the temperature of the aerosol, particularly the first aerosol, and prevents the aerosol from burning the user's mouth upon entering the mouthpiece. In some embodiments, referring to Figure 7, there is one heating layer 32, and the heating layer 32 is arranged toward the middle of the tube base 33, so that the fast-rise zone 35 is located in the middle area of the tube base 33, and there are two slow-rise zones 36, which are respectively located above and below the fast-rise zone 35. This embodiment can quickly generate the first aerosol and prevent the aerosol from burning the mouth.

Based on the first aspect, in some embodiments, there are at least two heating layers 32, and multiple heating layers 32 are arranged along the axial direction of the heating tube 3, and there is a gap between two adjacent heating layers 32, and at least part of the slow rise zone 36 is formed between the two spaced heating layers 32.

Secondly, the heating layer 32 includes a fast heating layer and a slow heating layer. The resistivity of the fast heating layer is greater than that of the slow heating layer. Therefore, the resistance per unit area or unit length of the fast heating layer is greater than that of the slow heating layer. Therefore, under the same current, the heating efficiency of the fast heating layer is greater than that of the slow heating layer. Specifically, the fast heating zone 35 includes the area on the heating zone covered by the fast heating layer, and the slow heating zone 36 includes the area on the heating zone covered by the slow heating layer. As a result, the heating rate of the fast heating zone is greater than that of the slow heating zone.

In some embodiments, there is one fast heating layer and one slow heating layer. The fast heating layer can be positioned closer to the upper end of the tube base 33, thereby being located above the slow heating layer, such that the fast-rise zone 35 is located above the slow-rise zone 36; the fast heating layer can be positioned closer to the lower end of the tube base 33, thereby being located below the slow heating layer, such that the fast-rise zone 35 is located below the slow-rise zone 36.

In some embodiments, there are at least two fast-heating layers, with two adjacent fast-heating layers separated by a slow-heating layer. Therefore, there are at least two fast-rise zones 35, and two adjacent fast-rise zones 25 are located above and below a slow-rise zone, respectively. In some embodiments, there are at least two slow-heating layers, with two adjacent slow-heating layers separated by a fast-heating layer. Therefore, there are at least two slow-rise zones 36, and two adjacent slow-rise zones 36 are located above and below a fast-rise zone, respectively.

It should be noted that in other embodiments, the resistance of the fast heating layer per unit area or unit length can be made greater than the resistance of the slow heating layer by making the current passing through the fast heating layer thinner than the current passing through the slow heating layer, thereby making the heating efficiency of the fast heating layer greater than that of the slow heating layer under the same current.

It should be noted that, in the first aspect and the second aspect, the energy output of the induction coil 4 and the heating tube 3 can be linked or independent.

Third, part of the material that makes up the heating layer 32 is a sensitive material, enabling the heating layer 32 to convert and utilize electromagnetic energy and generate eddy currents to generate heat. Based on this, part of the heating layer 32 is located within the surrounding range of the induction coil 4, so that this part of the heating layer 32 can convert part of the electromagnetic energy generated by the induction coil 4 into thermal energy; part of the heating layer 32 is located outside the surrounding range of the induction coil 4, so that this part of the heating layer 32 cannot convert part of the electromagnetic energy generated by the induction coil 4 into thermal energy, or can only convert a small amount of the electromagnetic energy generated by the induction coil 4 into thermal energy. Specifically, the fast-rise zone 35 includes the area on the heating zone that is covered by the heating layer 32 and located within the surrounding range of the induction coil 4, and the slow-rise zone 36 includes the area on the heating zone that is covered by the heating layer 32 and located outside the surrounding range of the induction coil 4. As a result, the heating rate of the fast-rise zone 35 is greater than the heating rate of the slow-rise zone 36.

In the embodiment shown in FIG8 , there is a single heating layer 32, and the portion of the heating layer 32 toward the lower end of the heating tube 3 is surrounded by the induction coil 4, while the portion of the heating layer 32 toward the upper end of the heating tube 3 is outside the surrounding range of the induction coil 4. Consequently, the fast-rise zone 35 is located below the slow-rise zone 36. In the embodiment shown in FIG9 , there is a single heating layer 32, and the portion of the heating layer 32 toward the upper end of the heating tube 3 is surrounded by the induction coil 4, while the portion of the heating layer 32 toward the lower end of the heating tube 4 is outside the surrounding range of the induction coil 4. Consequently, the fast-rise zone 35 is located above the slow-rise zone 36. In the embodiment shown in FIG10 , there is a single heating layer 32, and the middle region of the heating layer 32 is surrounded by the induction coil 4. Both the portion of the heating layer 32 toward the upper end and the portion toward the lower end of the heating tube 3 are outside the surrounding range of the induction coil 4. Consequently, there are two slow-rise zones 36, with the fast-rise zone 35 located between the two slow-rise zones 35.

In the embodiments shown in Figures 8-10, the length of the heating layer 32 is greater than or equal to the length of the induction coil 4, so that at least a portion of the heating layer 32 is necessarily located outside the surrounding range of the induction coil 4. In some embodiments, there are multiple induction coils 4, and the multiple induction coils 4 are arranged along the axial direction of the heating tube 3, with a gap between adjacent induction coils 4, and at least a portion of the slow-rise zone 36 is formed between the two spaced-apart induction coils 4.

However, based on the third aspect of the present application, it is optional and not mandatory for the length of the heating layer 32 to be greater than or equal to the length of the induction coil 4. In other embodiments of the third aspect, the length of the heating layer 32 may be less than the length of the induction coil 4. In some embodiments, a portion of the heating layer 32 and a portion of the induction coil 4 may be staggered in the axial direction of the heating tube 3, rather than corresponding to each other, so that the orthographic projection of the portion of the heating layer 32 in the direction of the induction coil 4 overlaps with the induction coil 4, and the orthographic projection of the portion of the heating layer 32 in the direction of the induction coil 4 does not overlap with the induction coil 4.

Based on the first, second or third aspects, the stronger the ability of the heating layer 32 to convert and utilize electromagnetic energy, the stronger its magnetic shielding ability, the more it can prevent the electromagnetic energy generated by the induction coil 4 from being received by the sensor 5 located inside the heating tube 3, or the more it can reduce the magnetic field strength or magnetic field energy received by the sensor 5 located inside the heating tube 3, thereby more it can affect the speed of temperature increase of the sensor 5 and the heating temperature of the sensor 5.

In order to reduce the effect of the heating layer 32 on the heating temperature and heating rate of the sensor 5, the heating layer 32 can be configured by adjusting the material and thickness of the heating layer 32 so that the heating layer 32 is configured to have a conversion efficiency of less than 30% for the magnetic energy provided by the induction coil 4. For example, the heating layer 32 is configured to have a conversion efficiency of less than 25% for the magnetic energy provided by the induction coil 4; for example, the heating layer 32 is configured to have a conversion efficiency of less than 20% for the magnetic energy provided by the induction coil 4; for example, the heating layer 32 is configured to have a conversion efficiency of less than 15% for the magnetic energy provided by the induction coil 4; for example, the heating layer 32 is configured to have a conversion efficiency of less than 10% for the magnetic energy provided by the induction coil 4; for example, the heating layer 32 is configured to have a conversion efficiency of less than 5% for the magnetic energy provided by the induction coil 4.

As a result, most of the magnetic field energy provided by the induction coil 4 can pass through the heating layer 32 and be received and utilized by the susceptor 5. In some embodiments, the susceptor 5 can be made of a material with a higher magnetic permeability to improve the susceptor 5's ability to receive and convert and utilize magnetic field energy. For example, the susceptor 5 can have a higher efficiency in converting the magnetic energy provided by the induction coil 4 than the heating layer 32 does. Alternatively, the susceptor 5 can have a higher magnetic permeability than the heating layer 32.

The induction coil 4 can generate a variable magnetic field between 1 Hz and 30 MHz, for example, between 2 Hz and 10 MHz, for example, between 5 Hz and 7 MHz, and further, between 2 kHz and 20 MHz. In some embodiments, the induction coil 4 can generate a variable magnetic field having a field strength (H field) between 1 A/m and 5 kA/m, for example, between 2 A/m and 3 kA/m, for example, about 2.5 kA/m.

In some embodiments, the conversion efficiency of the electromagnetic energy provided by the heating layer 32 to the induction coil 4 is reduced by setting the frequency of the magnetic field generated by the induction coil 4. Thus, the induction coil 4 can generate a varying magnetic field of less than or equal to 10 MHz; further, the induction coil 4 can generate a varying magnetic field of less than or equal to 6.78 MHz; and further, the induction coil 4 can generate a varying magnetic field of less than or equal to 2.5 MHz.

In some embodiments, the induction coil 4 generates a variable magnetic field between 500 KHz and 2.5 MHz, so as to reduce the conversion efficiency of the electromagnetic energy provided by the heating layer 32 to the induction coil 4 while ensuring that the temperature of the susceptor 5 increases at a higher rate.

Please refer to Table 1, which shows the conversion efficiency of electromagnetic energy provided by the heating tube 3 to the induction coil 4 and the conversion efficiency of electromagnetic energy provided by the sensor 5 to the induction coil under the changing magnetic fields of different frequencies generated by the induction coil 4, for the aerosol generating device provided in one embodiment of the present application.

Table 1: Comparison of the conversion efficiency of the heating tube and the susceptor to the electromagnetic energy provided by the induction coil

The data in Table 1 are obtained by impedance analyzer. The following briefly describes the specific detection and calculation method of the conversion efficiency of the heating tube to electromagnetic energy, taking the electromagnetic frequency of 1.6MHz as an example:

First, a 1.6 MHz changing magnetic field is provided to the induction coil 4 . Without the heating tube 3 and the sensor 5 , the AC resistance Rs1 of the induction coil 4 is detected when no load is applied. Rs1 is 16.74 mΩ.

Then, the heating tube 3 is placed in the sensing coil 4, and the AC resistance Rs2 of the sensing coil 4 is detected. Rs2 = 22.14 mΩ.

Afterwards, at least a portion of the sensor 5 is placed inside the heating tube 3 , and the AC resistance Rs3 of the induction coil 4 is measured at this time, where Rs3 = 222.17 mΩ.

Then, the conversion efficiency η1 of the 1.6 MHz changing magnetic field provided by the heating tube 3 to the induction coil 4 is:
eta1=100%*(Rs2-Rs1)/Rs3=100%*(22.14-16.74)/222.17=2.4%.

The conversion efficiency η2 of the 1.6 MHz changing magnetic field provided by the induction coil 4 to the sensor 5 is:
eta2=100%*(Rs3-Rs2)/Rs3=100%*(222.17-22.14)/222.17=90.0%.

In some embodiments, the heating layer 32 does not contain ferromagnetic metal or an alloy of ferromagnetic metal, or even does not contain sensitive materials, so as to minimize the conversion efficiency of the heating layer 32 to electromagnetic energy.

In some embodiments, the thickness of the heating layer 32 is between 400nm and 900nm. By making the heating layer 3 have a smaller thickness, the heating layer 32 has a larger resistance and heating efficiency while significantly reducing the conversion efficiency of the heating layer 32 to electromagnetic energy.

Under the premise that the conversion efficiency of electromagnetic energy of the heating layer 32 is low, or the heating layer 32 has no conversion efficiency for electromagnetic energy, or the magnetic permeability of the heating layer 32 is low, in order to make the fast-rise zone 35 have a higher temperature or a faster heating rate, in some embodiments, the power supply component 2 is electrically connected to the heating layer 32 to provide electrical energy to the heating layer 32. Therefore, the energy of the heating layer 32 mainly comes from the conversion and utilization of the electrical energy provided by the power supply component 2.

Based on the first aspect or the second aspect of the present application, in some embodiments, the length of the heating layer 32 is less than the length of the induction coil 4, or the length of the heating layer 32 is greater than or equal to the length of the induction coil 4; in some embodiments, the heating layer 32 is completely outside the surrounding range of the induction coil 4, or is completely within the surrounding range of the induction coil 4.

Based on the first, second, or third aspects of the present application, in some embodiments, with reference to FIG. 2 , a thermal insulation layer 6 is provided between the heating tube 3 and the induction coil 4 . The thermal insulation layer 6 may be a gas insulation layer or a negative pressure layer, or may be aerogel, felt, fiberglass, or the like. The thermal insulation layer 6 insulates and retains heat from the heating tube 3 , thereby reducing power consumption of the heating tube 3 and reducing heat release from the heating tube 3 toward the induction coil 4 , thereby preventing the induction coil 4 from overheating.

It should be noted that any two aspects of the first aspect, the second aspect and the third aspect of the present application can be combined with each other, and the first aspect, the second aspect and the third aspect of the present application can be combined with each other.

It should be noted that the specification and drawings of this application provide preferred embodiments of the present application, but are not limited to the embodiments described in this specification. Furthermore, it is possible for a person skilled in the art to make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims (18)

An aerosol generating device, characterized by comprising: a heating tube having an insertion opening through which an aerosol-generating substrate of an aerosol-generating article can be inserted, the heating tube comprising a heat-generating layer and a tube substrate, the heat-generating layer covering at least a portion of a heating zone of the tube substrate so that the heating tube can heat the aerosol-generating substrate; and an induction coil, surrounding the periphery of the heating tube, for generating a changing magnetic field; The aerosol generating device or the aerosol generating article is further provided with a susceptor capable of generating heat in a changing magnetic field, the susceptor being used to heat the aerosol generating substrate from the inside; Wherein, the aerosol generating device is configured so that the induction coil and the heating tube output energy independently of each other. The aerosol generating device according to claim 1, wherein the heating layer is configured so that the conversion efficiency of the electromagnetic energy provided by the induction coil satisfies one of the following conditions: Less than 30%; Less than 25%; Less than 20%; less than 10%; and Less than 5%. The aerosol generating device according to claim 2, wherein the induction coil is configured to generate a varying magnetic field of less than or equal to 10 MHz; or The induction coil is configured to generate a varying magnetic field less than or equal to 6.78 MHz; or The induction coil is configured to generate a varying magnetic field less than or equal to 2.5 MHz. The aerosol generating device according to claim 1, 2 or 3, wherein the heating layer does not contain ferromagnetic metal or an alloy of ferromagnetic metal. The aerosol generating device according to claim 1, 2 or 3, wherein the heating layer has a resistance of not less than 0.8Ω. The aerosol generating device according to claim 1 is characterized in that a portion of the heating zone is a fast-rise zone and a portion is a slow-rise zone, and the heating rate of the fast-rise zone is greater than the heating rate of the slow-rise zone. The aerosol generating device according to claim 6, wherein the heating layer has one or more heating layers, and the total length of the one or more heating layers is less than the length of the heating zone; The fast-rising zone includes an area on the heating zone covered by the heating layer, and the slow-rising zone includes an area on the heating zone not covered by the heating layer. The aerosol generating device according to claim 6, wherein the heating layer comprises a fast heating layer and a slow heating layer, and the resistivity of the fast heating layer is greater than the resistivity of the slow heating layer; The fast-rising zone includes an area on the heating zone covered by the fast-heating layer, and the slow-rising zone includes an area on the heating zone covered by the slow-heating layer. The aerosol generating device according to claim 6, wherein a portion of the heating layer is located within the surrounding range of the induction coil, and a portion of the heating layer is located outside the surrounding range of the induction coil; The fast-rising zone includes an area on the heating zone that is covered by the heating layer and is located within the surrounding range of the induction coil, and the slow-rising zone includes an area on the heating zone that is covered by the heating layer and is located outside the surrounding range of the induction coil. An aerosol-generating device according to claim 6, wherein the slow rise zone is configured to heat the aerosol-generating article by releasing at least part of the heat absorbed from the fast rise zone. The aerosol generating device according to any one of claims 6 to 10, wherein the insertion port is located at the upper end of the heating tube, and the fast-rise zone and the slow-rise zone meet one of the following conditions: The fast-rising zone is located above the slow-rising zone; The fast-rising zone is located below the slow-rising zone; There are at least two slow-rise zones, and two adjacent slow-rise zones are respectively located above and below one fast-rise zone; and There are at least two fast-rising zones, and two adjacent fast-rising zones are respectively located above and below one slow-rising zone. The aerosol generating device according to any one of claims 6 to 10, wherein the heating layer comprises an infrared radiation layer. The aerosol generating device according to any one of claims 6 to 9, wherein the heating layer is completely located within the surrounding range of the induction coil; or The heating layer is completely located outside the surrounding range of the induction coil. The aerosol generating device according to any one of claims 6 to 10, wherein the length of the heating layer is greater than or equal to the length of the induction coil; or The length of the heating layer is smaller than the length of the induction coil. The aerosol generating device according to claim 1, wherein the conversion efficiency of the electromagnetic energy provided by the heating layer to the induction coil is lower than the conversion efficiency of the electromagnetic energy provided by the susceptor to the induction coil. The aerosol generating device as described in claim 1 is characterized in that the aerosol generating device also includes a power supply component, the heating tube is electrically connected to the power supply component, and the energy of the heating layer mainly comes from the conversion and utilization of electrical energy provided by the power supply component. The aerosol generating device according to claim 1 is characterized in that the aerosol generating device further includes a power supply and a controller, the power supply being electrically connected to the induction coil and the heating tube, and the controller being electrically connected to the power supply for controlling the power supply to first provide power to the induction coil and then to provide power to the heating tube. An aerosol generating device, characterized by comprising: a heating tube capable of accommodating at least an aerosol-generating substrate of the aerosol-generating article, the heating tube comprising a heat-generating layer; and an induction coil, surrounding the periphery of the heating tube, for generating a changing magnetic field; The aerosol generating device or the aerosol generating article is further provided with a susceptor capable of generating heat in a changing magnetic field, and the susceptor is used to heat the aerosol generating substrate from the inside; The aerosol generating device is configured such that, in the changing magnetic field provided by the induction coil, the conversion efficiency of the heating layer to electromagnetic energy is no higher than 30%.