A sand bath standard test piece and a detection method for heat transfer performance of a center heating smoking set

Abstract

The present application belongs to the technical field of heating smoking set, and particularly relates to a sand bath standard test piece and a detection method for heat transfer performance of a center heating smoking set. The sand bath standard test piece comprises a tubular piece, the upper end of the tubular piece is open, the lower end has a bottom wall, the tubular piece is filled with sand particles, and a thermocouple insertion hole is arranged on the side wall or the bottom wall of the tubular piece; and a thermocouple is movably inserted into or withdrawn from the thermocouple insertion hole. The present application first proposes a method of using a test standard piece to detect the heat transfer performance of a center heating smoking set. The test standard piece does not use a cigarette, but selects sand particles, the specific heat of the sand particles is known, the sand particles can be uniformly filled, the gap can be controlled, the sand particles are not easy to wear and bond, the physical and chemical properties of the sand particles are stable, and the cost is low. The gap between the sand particles also well simulates the gap between tobacco. Therefore, the sand bath standard test piece is made of sand particles, which is simpler and more convenient for batch detection.

Description

Technical Field

[0001] This invention belongs to the field of heated smoke equipment technology, specifically relating to a standard test piece for sand baths and a method for testing the heat transfer performance of centrally heated smoke equipment. Background Technology

[0002] Traditional cigarettes release nicotine and flavor through direct combustion of tobacco to satisfy consumer demand. However, with increasing health awareness in recent years, heated tobacco products (HTPs) have emerged. HTPs utilize a heating device to heat tobacco products without combustion, thus releasing nicotine and flavor. While satisfying consumer smoking needs, they offer the advantage of reduced tar and harm compared to traditional cigarettes. Therefore, HTPs consist of both the device and the tobacco product, with the quality of the device directly determining the consumer's smoking experience. Many factors influence device quality, but the most crucial is the heat transfer performance during the heating process, which directly affects the release of substances from the tobacco product.

[0003] Currently, the main methods for measuring the heat transfer performance of heated tobacco products are infrared thermography and direct thermocouple measurement. Infrared thermography can only measure the temperature field distribution at equilibrium and cannot measure temperature fluctuations (heat transfer performance) during the heating process of tobacco products. Furthermore, infrared thermography is greatly affected by environmental factors; it requires penetrating the tobacco product shell for measurement, necessitating the use of new tobacco products (standard test pieces) for each measurement, significantly impacting the results. Direct thermocouple measurement of the heating element's temperature is convenient and has a fast response, but thermocouples can only measure the surface temperature, not the temperature outside the surface, and cannot measure the temperature field. Additionally, the confined space of the heating cavity makes thermocouple installation difficult, hindering large-scale batch testing. Moreover, thermocouples directly measure temperature rather than total heat generation, requiring conversion, which is not easy.

[0004] Therefore, neither of these two commonly used measurement methods can satisfy the judgment of the heat transfer performance of smoking devices.

[0005] To address the above problems, this invention is proposed. Summary of the Invention

[0006] The first aspect of this invention provides a standard test specimen for sand bathing, the standard test specimen for sand bathing comprising:

[0007] A tubular component 1, which has an opening at the upper end and a bottom wall at the lower end, is filled with sand, and has a thermocouple insertion hole 1-1 on its side wall or bottom wall.

[0008] Thermocouple 2, which can be movably inserted into or removed from the thermocouple insertion hole 1-1.

[0009] Preferably, the sand bath standard test piece includes a base 3, which is used to support and accommodate the tubular component 1. The outer wall of the tubular component 1 is provided with a cavity 6, which serves as a housing for the heating pipe wall of the smoking device.

[0010] Preferably, the sand bath standard test piece includes: a sealing cap 4 located at the upper end of the tubular component 1, the sealing cap 4 having a heating element insertion hole 4-1 at its center, the heating element insertion hole 4-1 being used to insert the central heating element of the heating device to be tested.

[0011] Preferably, the sand bath standard test piece includes: a heat insulation device 5 located below the tubular component 1, the heat insulation device 5 being used to insulate and maintain the heat of the tubular component 1.

[0012] Preferably, the particle size of the sand grains is 0.2~0.6mm. The sand grains of this invention are sand.

[0013] Preferably, the height of the sand grains is 2 / 3 to 49 / 50 of the height of the inner cavity of the tubular component 1, at which point the resistance is small when the heating element is inserted.

[0014] Of course, the solution of the present invention can also be achieved if the height of the sand grains is equal to the height of the inner cavity of the tubular component 1. However, the resistance is greater when the heating element is inserted, and it is also required that the space above the sand grains in the sealing cap 4 is greater than or equal to the volume of the heating element.

[0015] Preferably, the volume of the space not occupied by sand particles within the space jointly defined by the inner cavity of the tubular component 1 and the sealing cap 4 is greater than or equal to the volume of the heating element of the centrally heated smoke device to be tested.

[0016] A second aspect of the present invention provides a method for testing the heat transfer performance of a centrally heated smoke appliance, which uses the sand bath standard test specimen described in any one of the first aspects for testing, and the testing method includes the following steps:

[0017] Step 1: Insert the central heating element of the same batch of central heating smoke appliances upside down into the sand grains inside the tubular part 1 of the sand bath standard test piece described in any of the first aspects and fix it in place. The tubular part 1 is housed inside the heating tube of the central heating smoke appliance, and the heating tube wall of the central heating smoke appliance is located on the outer periphery of the tubular part 1.

[0018] Step 2: Insert the thermocouple 2 through the thermocouple insertion hole 1-1 into a specific position in the sand grains inside the tubular component 1;

[0019] Step 3: Start the central heating fume, collect the temperature change curve through the thermocouple 2, then turn off the central heating fume and remove the thermocouple 2 from the thermocouple insertion hole 1-1;

[0020] Step 4: Using heating fume hoods from the same batch but with different centers, repeat steps 1-3 multiple times to obtain the standard temperature curve range;

[0021] Step 5: Collect temperature change curves for the same batch of center-heated smoke appliances to be tested according to steps 1 to 3. If the temperature change curve falls within the range of the standard temperature curve in step 4, the heat transfer performance of this center-heated smoke appliance meets the requirements. If the temperature change curve is not within the range of the standard temperature curve in step 4, the heat transfer performance of this center-heated smoke appliance does not meet the requirements.

[0022] The data collection in step 4 above is repeated 3 to 10 times.

[0023] Each time the temperature change curve is collected in step 5 according to steps 1 to 3, it is necessary to wait until the sand in the tubular component 1 has completely cooled down.

[0024] Preferably, in step 3, when the thermocouple 2 is removed from the thermocouple insertion hole 1-1, the front end of the thermocouple 2 abuts against the outside of the thermocouple insertion hole 1-1 to prevent sand particles from leaking out of the tubular component 1.

[0025] Preferably, in step 3, before starting the central heating smoke appliance, the air inlet of the central heating smoke appliance is blocked to prevent heat loss.

[0026] Preferably, when the result of step 5 is that the heat transfer performance of this centrally heated smoke set meets the requirements, the following operation is performed:

[0027] Step 6: Using heating appliances from the same batch but with different centers, repeat steps 1-3 multiple times to obtain the fluctuation range of the standard temperature curve as the standard range;

[0028] If the temperature change curve of the same batch of centrally heated smoke appliances to be tested is within the above standard range, then the heat transfer performance of this centrally heated smoke appliance meets the requirements of the fluctuation range.

[0029] If the fluctuation range of the sand bath temperature change curve of the same batch of centrally heated smoke appliances to be tested is not within the above standard range, then the heat transfer performance of this centrally heated smoke appliance does not meet the requirements of the fluctuation range.

[0030] Preferably, in step 6, the fluctuation range of the standard temperature curve is the maximum or average value of the fluctuation range of the standard temperature curves of different center heating smoke appliances in the same batch.

[0031] Preferably, the heat transfer performance of the central heating fume is considered qualified only when it meets both the requirements of step 5 and the requirements of step 6.

[0032] The above technical solutions can be freely combined, provided they do not contradict each other.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. This invention is the first to propose a method using test standard components to test the heat transfer performance of center-heated smoking devices. Furthermore, the test standard component of this invention is not a cigarette but sand grains, preferably sand grains with a uniform particle size and a diameter of 0.2~0.6mm. Sand grains have a known specific heat, can be uniformly filled, have controllable gaps, are not easily worn, do not easily stick, have stable physicochemical properties, and are low in cost.

[0035] Furthermore, sand particles have stable bulk density and specific heat, do not decompose, and do not produce pollutants, making them ideal as test standards for batch testing of smoking devices. The gaps between sand particles also accurately simulate the gaps between tobacco shreds. Using sand particles to create sand bath standard test specimens is simpler and more convenient for batch testing.

[0036] If real cigarettes are used as standard test pieces for heating measurements, the following problems exist: 1. The specific heat and filling density of tobacco shreds vary, making them difficult to control. When using them as standard test pieces to batch test smoking devices, the comparability of the results is poor. Furthermore, cigarettes are easily damaged after repeated use, making them unsuitable for long-term repeated use as standard test pieces. 2. During the measurement process, condensate, local charred matter, residue, etc., will contaminate the smoking device being tested. 3. The properties of cigarettes change after thermal decomposition, making them unusable for repeated use.

[0037] 2. The sand bath standard test piece of the present invention is applicable to the testing of centrally heated smoke appliances. After the heating element is assembled into the smoke appliance, it is inserted upside down into the sand bath standard test piece. Since hot air flows from bottom to top, the heat insulation measures of the centrally heated smoke appliance can be used to prevent heat loss. In addition, the heat insulation device 5 of the sand bath standard test piece can also prevent the influence of heat loss.

[0038] 3. The method of the present invention facilitates batch testing.

[0039] 4. The method of inserting the heating element upside down into the sand bath standard test according to the present invention can also avoid sand leakage when the test standard is inserted into the smoking device. Attached Figure Description

[0040] Figure 1 This represents the range of the standard temperature variation curve for the smoking device in the first embodiment.

[0041] Figure 2 This is the temperature change curve of prototype 1 in the first embodiment.

[0042] Figure 3 This is the temperature change curve of prototype 2 in the first embodiment.

[0043] Figure 4This is a cross-sectional view of the sand bath standard test specimen when the thermocouple 2 is inserted into the tubular component 1 in the first embodiment.

[0044] Figure 5 This is a cross-sectional view of the sand bath standard test specimen when the thermocouple 2 is inserted into the tubular component 1, in the first embodiment. Figure 4 The cross-sectional angles differ by 90 degrees.

[0045] Figure 6 This is a cross-sectional view taken when the central heating element is inserted into a standard sand bath test piece during the heat transfer performance testing of a centrally heated smoke appliance.

[0046] Figure 7 This is a cross-sectional view taken when the central heating element is inserted into a standard sand bath test piece during the heat transfer performance testing of centrally heated smoke appliances. Figure 6 The cross-sectional angles differ by 90 degrees.

[0047] List of reference numerals in the attached diagram:

[0048] 1. Tubular component; 1-1. Thermocouple insertion hole; 2. Thermocouple; 3. Base; 4. Sealing cap; 4-1. Heating element insertion hole; 5. Heat insulation device; 6. Cavity. Detailed Implementation

[0049] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product instructions. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0050] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “coupled” to another element, it can be directly coupled to the other element, or there may be intermediate elements. Furthermore, the term “coupled” as used herein can include wireless coupling.

[0051] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. The terms "inner," "upper," "lower," etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0054] like Figure 1 A standard test specimen for sand baths, the standard test specimen for sand baths comprising:

[0055] A tubular component 1, which has an opening at the upper end and a bottom wall at the lower end, is filled with sand and has a thermocouple insertion hole 1-1 on the bottom wall of the tubular component.

[0056] Thermocouple 2 is connected to a telescopic device, which can be movably inserted into or removed from the thermocouple insertion hole 1-1.

[0057] The sand bath standard test piece includes a base 3, which is used to support and accommodate the tubular component 1. The outer wall of the tubular component 1 is provided with a cavity 6, which serves as a housing for the heating pipe wall of the smoking device.

[0058] The sand bath standard test piece includes: a sealing cap 4 located at the upper end of the tubular part 1, and a heating element insertion hole 4-1 is provided in the center of the sealing cap 4, which is used to insert the central heating element of the heating smoke device to be tested.

[0059] The sealing cap 4 is connected to the tubular component 1 by snapping the sealing cap 4 into the inner wall of the tubular component 1.

[0060] The sand bath standard test piece includes: a heat insulation device 5, which is located below the tubular component 1, and the heat insulation device 5 is used to insulate and keep the tubular component 1 warm.

[0061] The particle size of the sand is 0.2~0.6mm.

[0062] The height of the sand grains is 2 / 3 to 49 / 50 of the height of the inner cavity of the tubular component 1, so that the height of the sand grains increases slightly after the heating element is inserted. When the heating element is inserted, the slightly increased height of the sand grains will fill the space defined by the inner cavity of the tubular component 1 and the sealing cap 4.

[0063] The present invention discloses a method for testing the heat transfer performance of a centrally heated smoke appliance, using the aforementioned sand bath standard test specimen. The testing method includes the following steps:

[0064] Step 1: Insert the central heating element of the same batch of central heating smoke appliances upside down into the sand grains inside the tubular part 1 of the sand bath standard test piece described in any of the first aspects through the heating element insertion hole 4-1 and fix it in position. The tubular part 1 is housed in the heating tube of the central heating smoke appliance, and the heating tube wall of the central heating smoke appliance is located on the outer periphery of the tubular part 1.

[0065] Step 2: Insert the thermocouple 2 through the thermocouple insertion hole 1-1 into a specific position in the sand grains inside the tubular component 1;

[0066] Step 3: Start the central heating fume, collect the temperature change curve through the thermocouple 2, then turn off the central heating fume and remove the thermocouple 2 from the thermocouple insertion hole 1-1;

[0067] Step 4: For each test, use heating appliances from the same batch but with different centers, and repeat steps 1 to 3 multiple times to obtain the standard temperature curve range. The standard temperature curve range is defined by the upper limit temperature change curve and the lower limit temperature change curve.

[0068] Step 5: Collect temperature change curves for the same batch of center-heated smoke appliances to be tested according to steps 1 to 3. If the temperature change curve falls within the range of the standard temperature curve in step 4, the heat transfer performance of this center-heated smoke appliance meets the requirements. If the temperature change curve is not within the range of the standard temperature curve in step 4, the heat transfer performance of this center-heated smoke appliance does not meet the requirements.

[0069] In step 3, when the thermocouple 2 is removed from the thermocouple insertion hole 1-1, the front end of the thermocouple 2 abuts against the outside of the thermocouple insertion hole 1-1 to prevent sand particles from leaking out of the tubular component 1.

[0070] In step 3, before starting the central heating smoke appliance, the air inlet of the central heating smoke appliance is blocked to prevent heat loss.

[0071] The following are the specific test experiments:

[0072] The first implementation method is as follows:

[0073] In this experiment, sand grains with a diameter of approximately 0.2 mm were filled into the tubular component 1 to form a sand bath. The theoretical heating temperature of the smoking device is 278 degrees Celsius. The heating element was inserted into the sand bath, and thermocouple 2 was inserted into a sand grain 3 mm from the center of the heating element, with an insertion depth of 10 mm. Heating of the smoking device was then started. For each test, smoking devices from the same batch but with different heating centers were used. Ten measurements were taken to obtain the standard temperature change curve range of the temperature measured by thermocouple 2 as a function of heating time. Figure 1 ,:

[0074] The temperature change curve of the sample smoking device 1 to be tested was collected according to steps 1-3. The temperature change curve of sample 1 is as follows: Figure 2 As shown, the temperature change curve of prototype 1 is not... Figure 1 The upper and lower limit curves are within the range, thus proving that the heat transfer performance of the tested smoking device prototype 1 is unqualified.

[0075] Collect temperature change curves for sample 2 of the smoking device to be tested according to steps 1-3. The temperature change curves of sample 2 are as follows: Figure 3 As shown in the figure, the temperature change curve of prototype 2 is in Figure 1 The heat transfer performance of the tested smoking device prototype 2 is within the range of the upper and lower limit curves, thus proving that the heat transfer performance of the prototype is qualified.

[0076] Figure 4 This is a cross-sectional view of the sand bath standard test specimen when the thermocouple 2 is inserted into the tubular component 1 in the first embodiment.

[0077] Figure 5 This is a cross-sectional view of the sand bath standard test specimen when the thermocouple 2 is inserted into the tubular component 1, in the first embodiment. Figure 4 The cross-sectional angles differ by 90 degrees.

[0078] Figure 6 This is a cross-sectional view taken when the central heating element is inserted into a standard sand bath test piece during the heat transfer performance testing of a centrally heated smoke appliance.

[0079] Figure 7 This is a cross-sectional view taken when the central heating element is inserted into a standard sand bath test piece during the heat transfer performance testing of centrally heated smoke appliances. Figure 6 The cross-sectional angles differ by 90 degrees.

[0080] Thermocouple 2 is inserted into tubular component 1 through insulation device 5.

Claims

1. A method for testing the heat transfer performance of a centrally heated smoke appliance, characterized in that, The following sand bath standard test specimens were used for testing. The sand bath standard test specimens include: A tubular component (1) has an open upper end and a bottom wall at the lower end. The tubular component (1) is filled with sand. A thermocouple insertion hole (1-1) is provided on the side wall or bottom wall of the tubular component. Thermocouple (2), which can be movably inserted into or removed from the thermocouple insertion hole (1-1); The sand bath standard test piece includes a base (3), which is used to support and accommodate the tubular component (1). The outer wall of the tubular component (1) is provided with a cavity (6), which serves as a heating pipe wall accommodating part of the smoking device. The detection method includes the following steps: Step 1: Insert the central heating element of the same batch of central heating smoke set upside down into the sand grains inside the tubular part (1) of the sand bath standard test piece and fix it in place. The tubular part (1) is housed in the heating tube of the central heating smoke set, and the heating tube wall of the central heating smoke set is located on the outer periphery of the tubular part (1). Step 2: Insert the thermocouple (2) through the thermocouple insertion hole (1-1) into the sand grains inside the tubular component (1); Step 3: Start the central heating fume, collect the temperature change curve through the thermocouple (2), then turn off the central heating fume and remove the thermocouple (2) from the thermocouple insertion hole (1-1). Step 4: Using heating fume hoods from the same batch but with different centers, repeat steps 1-3 multiple times to obtain the standard temperature curve range; Step 5: Collect temperature change curves for the same batch of centrally heated smoke appliances to be tested, following steps 1-3; If the temperature change curve falls within the range of the standard temperature curve in step 4, then the heat transfer performance of this center-heated smoke appliance meets the requirements; if the temperature change curve does not fall within the range of the standard temperature curve in step 4, then the heat transfer performance of this center-heated smoke appliance does not meet the requirements.

2. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, In step 3, when the thermocouple (2) is removed from the thermocouple insertion hole (1-1), the front end of the thermocouple (2) abuts against the outside of the thermocouple insertion hole (1-1) to prevent sand particles from leaking out of the tubular part (1).

3. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, In step 3, before starting the central heating smoke appliance, the air inlet of the central heating smoke appliance is blocked to prevent heat loss.

4. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, When the result of step 5 is that the heat transfer performance of this central heating fume meets the requirements, the following operations are performed: Step 6: Using heating appliances from the same batch but with different centers, repeat steps 1-3 multiple times to obtain the fluctuation range of the standard temperature curve as the standard range; If the temperature change curve of the same batch of centrally heated smoke appliances to be tested is within the above standard range, then the heat transfer performance of this centrally heated smoke appliance meets the requirements of the fluctuation range. If the fluctuation range of the sand bath temperature change curve of the same batch of centrally heated smoke appliances to be tested is not within the above standard range, then the heat transfer performance of this centrally heated smoke appliance does not meet the requirements of the fluctuation range.

5. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, The sand bath standard test piece includes: a sealing cap (4) located at the upper end of the tubular piece (1), and a heating element insertion hole (4-1) is provided in the center of the sealing cap (4), and the central heating element of the heating smoke device to be tested is inserted into the heating element insertion hole (4-1).

6. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, The sand bath standard test piece includes: a heat insulation device (5) located below the tubular component (1), the heat insulation device (5) for heat insulation of the tubular component (1).

7. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 1, characterized in that, The sand grains have a diameter of 0.2 to 0.6 mm and a height of 2 / 3 to 49 / 50 of the height of the inner cavity of the tubular component (1).

8. The method for testing the heat transfer performance of a centrally heated smoke set according to claim 5, characterized in that, Within the space jointly defined by the inner cavity of the tubular component (1) and the sealing cap (4), the volume not occupied by sand particles is greater than or equal to the volume of the heating element of the central heating device to be tested.

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