Conductive heat flow density test method

Abstract

The application discloses a conduction type heat flow density test method, comprising the following steps: according to a preset heating element, different heat flow densities and cooling water flow rates are given to determine an inlet and outlet water temperature difference; according to different heat flow densities and corresponding inlet and outlet water temperature differences, corresponding correction coefficients are determined, and a database corresponding to heat flow densities, cooling water flow rates, inlet and outlet water temperature differences and correction coefficients is established; according to a maximum cooling water flow rate and the database, a final cooling water flow rate and corresponding inlet and outlet water temperature difference are determined through iteration; and according to the final cooling water flow rate and corresponding inlet and outlet water temperature difference and the database, a corresponding heat flow density is determined. The method has the advantages of being capable of accurately measuring a high heat flow density heating element under the action of a matched cooling device, and having the advantages of simple measurement, a large measurement range and a long continuous test time.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a conductive heat flux density testing method. Background Technology

[0002] Currently, most heat flux density testing instruments on the market measure radiative heat flux density. Conductive heat flux density testing instruments are relatively small and have limited testing ranges, making it difficult to improve their performance. They cannot test heating elements with heat flux densities greater than 500 W / cm². Furthermore, high heat flux densities cause temperatures to rise rapidly, exceeding the instrument's tolerance temperature, making it impossible to measure heat flux density under steady-state conditions. In addition, heating elements are typically equipped with cooling devices in actual use. The placement of these cooling devices affects the heat flux density on various surfaces of the heating element. Therefore, existing heat flux density testing instruments that measure the heat flux density at the contact surface of the heating element using a flat plate contact method do not accurately measure the heat flux density at the contact surface after the addition of a cooling device, failing to accurately quantify the heat flux density of a particular surface of the heating element. Summary of the Invention

[0003] In view of the above-mentioned defects or improvement needs of the existing technology, the purpose of this invention is to provide a conductive heat flux density testing method.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A method for testing conductive heat flux density includes the following steps:

[0006] Based on the preset heating element, different heat flux densities and cooling water flow rates are given to determine the inlet and outlet water temperature difference;

[0007] Based on the different heat flux densities and the corresponding inlet and outlet water temperature differences, the corresponding correction coefficients are determined, and a database is established that corresponds one-to-one with heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficients.

[0008] Based on the maximum cooling water flow rate and the database, the final cooling water flow rate and the corresponding inlet and outlet water temperature difference are determined iteratively.

[0009] Based on the final cooling water flow rate, the corresponding inlet and outlet water temperature difference, and the database, the corresponding heat flux density is determined.

[0010] In one embodiment, the step of determining the inlet and outlet water temperature difference based on a preset heating element, given different heat flux densities and cooling water flow rates, includes:

[0011] Determine the thermal contact area of ​​the preset heating element.

[0012] In one embodiment, the step of determining the corresponding correction coefficient based on different heat flux densities and the corresponding inlet and outlet water temperature differences includes:

[0013]

[0014] Where f represents the correction coefficient, q represents the heat flux density, A represents the thermal contact area of ​​the preset heating element, Q represents the cooling water flow rate, Cp represents the specific heat capacity of the cooling water, and ΔT represents the temperature difference between the inlet and outlet water.

[0015] In one embodiment, the step of establishing a database with one-to-one correspondence between heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient includes:

[0016] Based on the assumed initial cooling water flow rate, the corresponding first simulated inlet and outlet water temperature difference is calculated through simulation.

[0017] Based on the assumed initial cooling water flow rate, the first simulated inlet and outlet water temperature difference, and the standard temperature difference, the adjusted cooling water flow rate is determined;

[0018] Based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within a preset range, a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

[0019] In one embodiment, if the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within a preset range and is lower than a preset value, the cooling water flow rate is reduced, and then the process returns to the step of calculating the corresponding second simulated inlet and outlet water temperature difference based on the adjusted cooling water flow rate. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within a preset range, a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

[0020] In one embodiment, if the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within a preset range and is higher than a preset value, the cooling water flow rate is increased. Then, based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within a preset range, a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

[0021] In one embodiment, the standard for both reducing and increasing the cooling water flow rate is 0.01 L / min.

[0022] In one embodiment, the step of iteratively determining the final cooling water flow rate and the corresponding inlet and outlet water temperature difference based on the maximum cooling water flow rate and the database includes:

[0023] The maximum value of the cooling water flow rate is determined from the database, and the first inlet and outlet temperature difference corresponding to the maximum cooling water flow rate is tested.

[0024] A first ratio is determined based on the first inlet / outlet temperature difference and the standard temperature difference, and a second cooling water flow rate is determined based on the first ratio and the maximum cooling water flow rate.

[0025] Test the second inlet and outlet temperature difference corresponding to the second cooling water flow rate, determine the database second temperature difference corresponding to the second cooling water flow rate according to the database, and if the difference between the second inlet and outlet temperature difference and the database second temperature difference is within a preset range, then determine the second cooling water flow rate as the final cooling water flow rate, and the second inlet and outlet temperature difference as the corresponding inlet and outlet water temperature difference.

[0026] The beneficial effects of this invention are as follows: Based on a preset heating element, different heat flux densities and cooling water flow rates are given to determine the inlet and outlet water temperature difference; based on different heat flux densities and corresponding inlet and outlet water temperature differences, corresponding correction coefficients are determined, and a database with one-to-one correspondence between heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficients is established; based on the maximum cooling water flow rate and the database, the final cooling water flow rate and corresponding inlet and outlet water temperature difference are iteratively determined; based on the final cooling water flow rate, corresponding inlet and outlet water temperature difference, and the database, the corresponding heat flux density is determined. This allows for accurate measurement of heating elements with high heat flux density under the action of a matching cooling device, and has the advantages of simple measurement, large measurement range, and long continuous testing time.

[0027] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0028] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a schematic diagram of the test environment. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0031] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in the specification of this application 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 combinations thereof.

[0033] 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 application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as in the embodiments of this application.

[0034] This invention provides a conductive heat flux density testing method, applicable to... Figure 1 The test environment shown.

[0035] like Figure 1 As shown, the test environment includes a heating element 1, an internal cooling device 2, a flow meter (not shown), and a thermometer (not shown).

[0036] The internal design of the cavity cooling device 2 features a surrounding flow channel. The bottom of the flow channel can be densely designed according to the thermal power characteristics of the heating element 1. A flow meter and a thermometer are installed at the inlet of the flow channel, and a thermometer is also installed at the outlet of the flow channel. A cover plate (not shown) is installed on the top of the flow channel. The cover plate can seal the entire cavity cooling device 2. It can be understood that the upper end of the cavity cooling device 2 is open, and a connector is installed on the cover plate for the power cord of the heating element 1 to enter and exit. It should be noted that the heating element 1 is placed in the cavity cooling device 2 and is tightly attached by thermal grease.

[0037] Since most of the heat from heating element 1 is carried away by the cooling water in the flow channel, and a small portion is conducted to the cooling device, causing the temperature to rise, calculating the heat flux density solely based on the heat carried away by the cooling water will result in an underestimation of the value, which needs to be corrected in advance.

[0038] The conductive heat flux density testing method provided in this embodiment includes steps S10-S40.

[0039] Step S10: Based on the preset heating element, give different heat flux densities and cooling water flow rates, and determine the inlet and outlet water temperature difference.

[0040] Numerical simulation requires coupling heat transfer and fluid mechanics modules for calculation. First, a heating element is preset, and its bottom surface contact area A is determined. Then, the heat flux density q and cooling water flow rate Q are given. Finally, the temperature difference between the inlet and outlet water is calculated through simulation.

[0041] Step S20: Determine the corresponding correction coefficients based on different heat flux densities and the corresponding inlet and outlet water temperature differences, and establish a database that corresponds one-to-one with heat flux density, cooling water flow rate, inlet and outlet water temperature differences, and correction coefficients.

[0042] Step S20, the step of determining the corresponding correction coefficient based on different heat flux densities and the corresponding inlet and outlet water temperature differences, includes:

[0043]

[0044] Where f represents the correction coefficient, q represents the heat flux density, A represents the thermal contact area of ​​the preset heating element, Q represents the cooling water flow rate, Cp represents the specific heat capacity of the cooling water, and ΔT represents the temperature difference between the inlet and outlet water.

[0045] Step S20, which involves establishing a database that corresponds one-to-one with heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficients, includes:

[0046] S201. Based on the assumed initial cooling water flow rate, calculate the corresponding first simulated inlet and outlet water temperature difference through simulation.

[0047] S202. Based on the assumed initial cooling water flow rate, the first simulated inlet and outlet water temperature difference, and the standard temperature difference (in this embodiment, the standard temperature difference is set to 3℃), determine the adjusted cooling water flow rate;

[0048] S203. Based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within the preset range (the preset range temperature range is [0℃, 0.1℃]), then a set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference and correction coefficient are obtained.

[0049] If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within the preset range and is lower than the preset value (i.e., the absolute value is less than 2.9℃), then the cooling water flow rate is reduced, and then the process returns to step S203.

[0050] If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within the preset range and is higher than the preset value (i.e., the absolute value is greater than 3.1℃), then increase the cooling water flow rate and return to step S203.

[0051] In this embodiment, the standard for both reducing and increasing the cooling water flow rate is 0.01 L / min.

[0052] Step S30: Based on the maximum cooling water flow rate and the database, iteratively determine the final cooling water flow rate and the corresponding inlet and outlet water temperature difference.

[0053] Specifically, step S30 includes:

[0054] S301. Determine the maximum value of the cooling water flow rate from the database and test the first inlet and outlet temperature difference corresponding to the maximum cooling water flow rate.

[0055] S302. Determine the first ratio based on the first inlet and outlet temperature difference and the standard temperature difference, and determine the second cooling water flow rate based on the first ratio and the maximum cooling water flow rate.

[0056] S303. Test the second inlet and outlet temperature difference corresponding to the second cooling water flow rate. Determine the database second temperature difference corresponding to the second cooling water flow rate based on the database. If the difference between the second inlet and outlet temperature difference and the database second temperature difference is within the preset range (less than 0.1℃), then determine the second cooling water flow rate as the final cooling water flow rate and the second inlet and outlet temperature difference as the corresponding inlet and outlet water temperature difference.

[0057] Understandably, in each iteration, the cooling water flow rate is adjusted to be the product of the previous cooling water flow rate, the previous inlet and outlet temperature difference, and the database temperature difference corresponding to the previous cooling water flow rate, until the difference between the inlet and outlet temperature difference and the corresponding database temperature difference is within a preset range, at which point the heat flux density can be determined.

[0058] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0059] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for testing conductive heat flux density, characterized in that, Includes the following steps: Based on the preset heating element, different heat flux densities and cooling water flow rates are given to determine the inlet and outlet water temperature difference; Based on the different heat flux densities and the corresponding inlet and outlet water temperature differences, the corresponding correction coefficients are determined, and a database is established that corresponds one-to-one with heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficients. Based on the maximum cooling water flow rate and the database, the final cooling water flow rate and the corresponding inlet and outlet water temperature difference are determined iteratively. Based on the final cooling water flow rate, the corresponding inlet and outlet water temperature difference, and the database, the corresponding heat flux density is determined. The step of determining the inlet and outlet water temperature difference based on a preset heating element, given different heat flux densities and cooling water flow rates, includes: Determine the thermal contact area of ​​the preset heating element; The step of determining the corresponding correction coefficient based on different heat flux densities and the corresponding inlet and outlet water temperature differences includes: f= ； in, Here, A represents the correction factor, q represents the heat flux density, A represents the pre-defined thermal contact area of ​​the heating element, and Q represents the cooling water flow rate. This indicates the specific heat capacity of cooling water. Indicates the temperature difference between the inlet and outlet water; The steps for establishing a database with one-to-one correspondences between heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficients include: Based on the assumed initial cooling water flow rate, the corresponding first simulated inlet and outlet water temperature difference is calculated through simulation. Based on the assumed initial cooling water flow rate, the first simulated inlet and outlet water temperature difference, and the standard temperature difference, the adjusted cooling water flow rate is determined; Based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within a preset range, a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

2. The conductive heat flux density testing method according to claim 1, characterized in that, If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within the preset range and is lower than the preset value, then the cooling water flow rate is reduced. Then, based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within the preset range, then a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

3. The conductive heat flux density testing method according to claim 2, characterized in that, If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is not within the preset range and is higher than the preset value, then the cooling water flow rate is increased. Then, based on the adjusted cooling water flow rate, the corresponding second simulated inlet and outlet water temperature difference is calculated through simulation. If the absolute value of the difference between the second simulated inlet and outlet water temperature difference and the standard temperature difference is within the preset range, then a corresponding set of heat flux density, cooling water flow rate, inlet and outlet water temperature difference, and correction coefficient are obtained.

4. The conductive heat flux density testing method according to claim 3, characterized in that, The standard for both reducing and increasing the cooling water flow rate is 0.01 L / min.

5. The conductive heat flux density testing method according to claim 1, characterized in that, The step of iteratively determining the final cooling water flow rate and the corresponding inlet and outlet water temperature difference based on the maximum cooling water flow rate and the database includes: The maximum value of the cooling water flow rate is determined from the database, and the first inlet and outlet water temperature difference corresponding to the maximum cooling water flow rate is tested. A first ratio is determined based on the first inlet and outlet water temperature difference and the standard temperature difference; a second cooling water flow rate is determined based on the first ratio and the maximum cooling water flow rate. Test the second inlet and outlet water temperature difference corresponding to the second cooling water flow rate, determine the database second temperature difference corresponding to the second cooling water flow rate according to the database, and if the difference between the second inlet and outlet water temperature difference and the database second temperature difference is within a preset range, then determine the second cooling water flow rate as the final cooling water flow rate, and the second inlet and outlet water temperature difference as the corresponding inlet and outlet water temperature difference.

Images