Method for judging maximum temperature of resistance tape by using colorimetric analysis

Abstract

The invention relates to a method for judging the highest temperature of a resistance tape by using colorimetric analysis. The method is characterized by comprising the following steps of: 1, manufacturing an electrothermal alloy sample by using a material which is the same as that of a to-be-analyzed resistance tape; 2, the electrothermal alloy sample is subjected to oxidation operation at multiple set temperatures, and an oxidized sample is obtained; 3, measuring the chromatic value of the oxidized sample; step 4, recording and storing the chromatic values of the plurality of oxidized samples at the plurality of set temperatures; and 5, comparing the chromatic value of the resistance tape to be analyzed with the recorded chromatic value of the oxidized sample to obtain the highest temperature of the resistance tape to be analyzed during working. According to the invention, the highest temperature experienced by the surface state of the resistance tape to be analyzed is analyzed, and test preparation before high temperature is not needed; observation is not needed during working, and the application range is wide; the analysis process is in a non-contact mode, and the surface is not damaged.

Description

Technical Field

[0001] The invention relates to the technical field of locomotive brake resistor testing and analysis, and in particular to a method for judging the maximum temperature of a resistor belt by applying chromaticity analysis. Background Art

[0002] The function realization process of the locomotive brake resistor device is as follows: when the locomotive performs resistance braking, the traction motor changes from the series-excited electric working condition to the separately-excited generating working condition, the kinetic energy of the locomotive is converted into electrical energy, and then converted into heat energy through the resistance belt of the brake resistor device, and the ventilator driven by the DC motor connected in parallel to the brake resistor blows the heat energy into the atmosphere. When the brake resistor device is working, the resistance belt is frequently heated and burned. As the power of the locomotive brake resistor device increases, the problem of high temperature heating and burning of the resistance belt is receiving more and more attention.

[0003] The problem of high temperature heating and burning of the resistor belt usually occurs locally in the resistor belt. This is related to the uneven distribution of cooling airflow in the flow channel and the structure of the resistor belt itself. To make relevant optimization and improvement work, it is necessary to obtain the highest temperature reached locally in the resistor belt. Moreover, the highest temperature reached by the resistor belt during work is also an important parameter of the working state of the brake resistor device.

[0004] The resistance band material of the locomotive brake resistor device is generally selected from high-resistance electric heating alloys such as Ni-Cr alloy and Fe-Cr-Al alloy. These electric heating alloys will oxidize on the surface in an air atmosphere, and the oxidation rate is related to the ambient temperature and time of the material. With different temperatures, the surface of these electric heating alloys will be oxidized to varying degrees, which is manifested as different thicknesses of the oxide film. The oxide film will produce interference colors on the surface of the electric heating alloy. Therefore, the highest temperature it has experienced during operation can be determined by analyzing the interference colors on the surface of the resistance band.

[0005] Currently, in engineering, the working temperature of resistance strips can be obtained by thermocouples, infrared temperature measurement, temperature-indicating paint and other methods, but the temperature measurement process is complicated, costly, and requires the test conditions to be arranged in advance. These methods are not applicable to resistance strips that are inconvenient to place thermocouples and temperature-indicating paint, and cannot be directly observed during operation. Summary of the invention

[0006] One of the objects of the present invention is to provide a method for determining the maximum temperature of a resistor strip using colorimetric analysis so as to provide a method for analyzing the maximum temperature experienced by a resistor strip in an air atmosphere.

[0007] The second purpose of the present invention is to provide a method for determining the maximum temperature of a resistance strip by using colorimetric analysis, which can provide a method for analyzing the maximum temperature experienced by a resistance strip that is inconvenient to place a thermocouple or temperature-indicating paint and cannot be directly observed during operation.

[0008] The third object of the present invention is to provide a method for determining the maximum temperature of a resistor strip by using colorimetric analysis, which can analyze the maximum temperature experienced by the resistor strip through the oxidation color of the surface of the resistor strip.

[0009] The technical solution of the present invention is: a method for determining the maximum temperature of a resistor band by using chromaticity analysis, which is characterized by comprising the following steps: Step 1: Prepare an electric heating alloy sample using the same material as the resistance band to be analyzed; Step 2, performing oxidation operation on the electrothermal alloy sample at various set temperatures to obtain oxidation samples; Step 3, measuring the chromaticity value of the oxidized sample; Step 4, recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures; Step 5: Compare the chromaticity value of the resistance band to be analyzed with the recorded chromaticity value of the oxidation sample to obtain the highest temperature reached by the resistance band to be analyzed when it is working.

[0010] The step 1 specifically includes the following steps: The electrothermal alloy samples were made into 20mm×20mm square slices using shearing and other non-heat-generating processes. The surfaces of the electrothermal alloy samples were polished, cleaned, degreased, and activated. The purpose of these steps was to remove surface dust, oil, and oxide layer to improve the quality of subsequent oxide films.

[0011] The operation of step 1 also includes polishing the sample using 400, 800, 1200, 1500, and 2000 sandpaper in sequence; Ultrasonic pre-degreasing is performed in acetone and anhydrous ethanol solutions in sequence, and then degreasing is performed in an alkaline solution; Then, activation treatment was performed with 10% H2SO4 at room temperature for 15 min; The step 2 specifically includes the following steps: Place the electrothermal alloy sample in a heating furnace and heat it at the set temperature for more than 20 minutes. After the electrothermal alloy sample cools down naturally, an oxidized sample is obtained. The set temperature range of the heating furnace is 200°C to 800°C, with an interval of 50°C or less. This step will record the highest heating temperature that the corresponding oxidized sample has been subjected to.

[0012] The step 2 may be the following steps: Power is supplied to the electrothermal alloy sample to make it generate heat. The power supply is controlled to heat the electrothermal alloy sample to the set temperature and maintain the temperature for more than 20 minutes. The power is then turned off and an oxidized sample is obtained after the electrothermal alloy sample cools down naturally. When this method is used, chromaticity sampling should be carried out at the point where the oxidized sample current is uniform.

[0013] The step three is specifically as follows: using a spectrophotometer to measure the chromaticity values ​​of the oxidized sample at different positions on the surface, and taking the average value.

[0014] The step 4 specifically includes: recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures.

[0015] The step five is specifically as follows: using a spectrophotometer to measure the chromaticity value of the resistance band to be analyzed, and comparing it with the recorded chromaticity value of the oxidation sample to obtain the maximum temperature reached by the resistance band to be analyzed when it is working.

[0016] The advantages of the present invention are: 1. The present invention uses the highest temperature experienced by the surface state analysis of the resistor strip to be analyzed, and does not require test preparation before experiencing high temperature; 2. The present invention uses the highest temperature experienced by the surface state analysis of the resistor strip to be analyzed, and does not need to be observed during its operation, so it has a wide range of applications; 3. The present invention uses the highest temperature experienced by the surface state analysis of the resistor strip to be analyzed, and the analysis process is non-contact and does not damage its surface; BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the embodiment of the present invention or the existing design method, the following briefly introduces the drawings required in the description of the embodiment or the existing design method: Figure 1 It is a schematic diagram of the process of Example 1 of the present invention.

[0018] Figure 2 It is a schematic diagram of the flow chart of Example 2 of the present invention. DETAILED DESCRIPTION

[0019] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so as to fully understand and implement the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0020] Meanwhile, in the following description, many specific details are set forth for the purpose of explanation to provide a thorough understanding of the embodiments of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the specific details or the specific manner described herein. Example

[0021] like Figure 1 As shown, the present invention relates to a method for determining the maximum temperature of a resistor band by using chromaticity analysis, comprising: Step 1: Prepare an electric heating alloy sample using the same material as the resistance band to be analyzed; Step 2, performing oxidation operation on the electrothermal alloy sample at various set temperatures to obtain oxidation samples; Step 3, measuring the chromaticity value of the oxidized sample; Step 4, recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures; Step 5: Compare the chromaticity value of the resistance band to be analyzed with the recorded chromaticity value of the oxidation sample to obtain the highest temperature reached by the resistance band to be analyzed when it is working.

[0022] The method of the embodiment of the present invention can perform surface colorimetric analysis on the resistor strip to be analyzed to obtain the highest temperature reached when the resistor strip is working. The embodiment of the present invention does not require test preparation before the resistor strip is subjected to high temperature, does not require observation when the resistor strip is working, has a wide range of applications, and the analysis process is non-contact and does not damage the surface of the resistor strip.

[0023] The step 1 specifically includes the following steps: The electrothermal alloy samples were made into 20mm×20mm square slices using shearing and other non-heat-generating processes. The surfaces of the electrothermal alloy samples were polished, cleaned, degreased, and activated. The purpose of these steps was to remove surface dust, oil, and oxide layer to improve the quality of subsequent oxide films.

[0024] In the operation of the above step 1 in the embodiment of the present invention, the sample is polished using 400, 800, 1200, 1500, and 2000 sandpapers in sequence.

[0025] Ultrasonic pre-degreasing is carried out in acetone and anhydrous ethanol solutions in sequence, and then degreasing is carried out in an alkaline solution.

[0026] Then activation treatment was carried out with 10% H2SO4 at room temperature for 15 minutes.

[0027] The step 2 specifically includes the following steps: Place the electrothermal alloy sample in a heating furnace and heat it at the set temperature for more than 20 minutes. After the electrothermal alloy sample cools down naturally, an oxidized sample is obtained. The set temperature range of the heating furnace is 200℃~800℃, with an interval of 50℃ or less. This step will record the highest heating temperature that the corresponding oxidized sample has been subjected to.

[0028] The step 2 may be the following steps: Power is supplied to the electrothermal alloy sample to make it generate heat. The power supply is controlled to heat the electrothermal alloy sample to the set temperature and maintain the temperature for more than 20 minutes. The power is then turned off and an oxidized sample is obtained after the electrothermal alloy sample cools down naturally. When this method is used, chromaticity sampling should be carried out at the point where the oxidized sample current is uniform.

[0029] The step three is specifically as follows: using a spectrophotometer to measure the chromaticity values ​​of the oxidized sample at different positions on the surface, and taking the average value.

[0030] The step 4 specifically includes: recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures.

[0031] The step five is specifically as follows: using a spectrophotometer to measure the chromaticity value of the resistance band to be analyzed, and comparing it with the recorded chromaticity value of the oxidation sample to obtain the maximum temperature reached by the resistance band to be analyzed when it is working. Example

[0032] like Figure 2 As shown, an embodiment of the present invention provides a method for determining the maximum temperature of a resistor band by applying chromaticity analysis, comprising: Step 1: Prepare an electric heating alloy sample using the same material as the resistance band to be analyzed; Step 2, performing oxidation operation on the electrothermal alloy sample at various set temperatures to obtain oxidation samples; Step 3: Make a color card using the oxidation sample itself; Step 4: Use a color card made of an oxidized sample to compare the resistance band to be analyzed to obtain the highest temperature reached by the resistance band to be analyzed when it is working.

[0033] The method of the embodiment of the present invention can perform surface chromaticity analysis on the resistor strip to be analyzed to obtain the highest temperature reached when it is working; the embodiment of the present invention does not require test preparation before the resistor strip is subjected to high temperature, does not require observation when it is working, has a wide range of applications, and the analysis process is non-contact and does not damage the surface of the resistor strip.

[0034] Step one also includes: making the electrothermal alloy sample into a square sheet of 20mm×20mm, preferably by shearing or other non-heat-generating processing, and grinding, polishing, cleaning, degreasing, and activating the surface of the electrothermal alloy sample; the purpose of step one is to remove surface dust, oil and oxide layer to improve the quality of subsequent oxide film.

[0035] In the operation of the above step 1 in the embodiment of the present invention, the sample is polished with 400, 800, 1200, 1500, and 2000 water sandpaper in sequence; ultrasonic pre-degreasing is carried out in acetone and anhydrous ethanol solutions in sequence, and then degreasing is carried out in an alkaline solution, and activation treatment is carried out with 10% H2SO4, the temperature is room temperature, and the time is 15 minutes.

[0036] Step 2 is as follows: put the electrothermal alloy sample into a heating furnace and heat it at the set temperature for more than 20 minutes, and then obtain an oxidized sample after the electrothermal alloy sample cools down naturally. The set temperature range of the heating furnace is 200℃~800℃, with an interval of 50℃ or less. In this step, the highest heating temperature that the corresponding oxidized sample has to bear should be recorded.

[0037] Step two may also be: power on the electrothermal alloy sample to generate heat, control the power supply to heat the electrothermal alloy sample according to the set temperature, maintain the temperature for more than 20 minutes, cut off the power supply, and obtain the oxidation sample after the electrothermal alloy sample cools down naturally. When using this method, chromaticity sampling should be carried out at the point where the oxidation sample current is uniform.

[0038] Step three is as follows: a color card is made with the oxidation sample itself, and the specific color oxidation sample is matched with its highest heating temperature.

[0039] Step 4 is specifically as follows: compare the resistance band to be analyzed with the color card made of the oxidized sample, and the highest heating temperature corresponding to the color card with the closest color is the highest temperature reached by the resistance band to be analyzed when it is working.

[0040] The working principle of the present invention is: when the resistance belt of the locomotive brake resistor device is in a high temperature environment during operation, an extremely thin and dense oxide film will be generated on the surface. The higher the temperature, the faster the oxidation rate and the thicker the oxide film. Under the condition that the environmental conditions remain unchanged, when the thickness of the oxide film reaches a certain level, the metal elements cannot penetrate this thick oxide film, the oxidation reaction rate tends to stagnate, and the film layer no longer grows thicker. Therefore, after the oxidation process reaches a certain period of time, the thickness of the oxide film on the surface of the resistance belt is related to the temperature of the environment in which it is located.

[0041] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in the field without departing from the concept and principle of the present invention, as well as applications to fields not mentioned in the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A method for determining the maximum temperature of a resistor band using chromaticity analysis, characterized in that: The steps include: Step 1: Prepare an electric heating alloy sample using the same material as the resistance band to be analyzed; Step 2, performing oxidation operation on the electrothermal alloy sample at various set temperatures to obtain oxidation samples; Step 3, measuring the chromaticity value of the oxidized sample; Step 4, recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures; Step 5: Compare the chromaticity value of the resistance band to be analyzed with the recorded chromaticity value of the oxidation sample to obtain the highest temperature reached by the resistance band to be analyzed when it is working.

2. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, wherein: The step 1 specifically includes the following steps: The electrothermal alloy sample was made into a 20mm×20mm square sheet by a non-heat-generating process such as shearing. The surface of the electrothermal alloy sample was polished, cleaned, degreased, and activated. The purpose of the above steps is to remove surface dust, oil and oxide layer to improve the quality of subsequent oxide film.

3. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, wherein: The operation of step 1 also includes polishing the sample using 400, 800, 1200, 1500, and 2000 sandpaper in sequence; Ultrasonic pre-degreasing is performed in acetone and anhydrous ethanol solutions in sequence, and then degreasing is performed in an alkaline solution; Then, activation treatment was performed with 10% H2SO4 at room temperature for 15 min; The step 2 specifically includes the following steps: Place the electrothermal alloy sample in a heating furnace and heat it at the set temperature for more than 20 minutes. After the electrothermal alloy sample cools down naturally, an oxidized sample is obtained. The set temperature range of the heating furnace is 200℃~800℃, with an interval of 50℃ or less. This step will record the highest heating temperature that the corresponding oxidized sample has been subjected to.

4. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, wherein: The step 2 may be the following steps: Power is supplied to the electrothermal alloy sample to make it generate heat. The power supply is controlled to heat the electrothermal alloy sample to the set temperature and maintain the temperature for more than 20 minutes. The power is then turned off and an oxidized sample is obtained after the electrothermal alloy sample cools down naturally. When this method is used, chromaticity sampling should be carried out at the point where the oxidized sample current is uniform.

5. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, wherein: The step three is specifically as follows: using a spectrophotometer to measure the chromaticity values ​​of the oxidized sample at different positions on the surface, and taking the average value.

6. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, characterized in that: The step 4 specifically includes: recording and storing the chromaticity values ​​of multiple oxidation samples at multiple set temperatures.

7. The method for determining the maximum temperature of a resistor band by using chromaticity analysis according to claim 1, characterized in that: The step five is specifically as follows: using a spectrophotometer to measure the chromaticity value of the resistance band to be analyzed, and comparing it with the recorded chromaticity value of the oxidation sample to obtain the maximum temperature reached by the resistance band to be analyzed when it is working.

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