A method and device for decolorizing, dehydrating, and recycling waste transformer oil

Abstract

The present invention relates to the field of transformer oil recovery and treatment, and specifically to a waste transformer oil decolorization, dehydration, and recovery method and apparatus thereof. The method comprises identifying a first impurity characteristic of the waste transformer oil, preliminarily setting operating parameters for a decolorization treatment process, identifying impurity adsorption conditions, and adjusting flow parameters of the waste transformer oil in an adsorbent to ensure sufficient contact between the waste transformer oil and the adsorbent; identifying a second impurity characteristic of the waste transformer oil, replacing the adsorbent, and re-adjusting the operating parameters and flow parameters until the waste transformer oil meets the decolorization requirements, and promptly replacing the adsorbent that is saturated with adsorption to ensure reliable decolorization of the waste transformer oil; and identifying the dehydrating agent form of the waste transformer oil that meets the decolorization requirements in the dehydration treatment process, obtaining the water absorption properties of the dehydrating agent, and adjusting the dehydration process accordingly to maximize dehydration efficiency. The present invention can avoid the generation of secondary pollutants, reduce the cost of waste transformer oil recovery, and improve the decolorization and dehydration treatment efficiency.

Description

Technical Field

[0001] The present invention relates to the field of transformer oil recovery and treatment, and in particular to a method and device for decolorizing, dehydrating and recovering waste transformer oil. Background Art

[0002] Transformer oil is used in electrical equipment such as transformers, low-temperature switches, and transformers, providing insulation and cooling. During daily operation, exposed to oxygen, high temperatures, metal ions, and sunlight, transformer oil undergoes oxidation reactions with the atmosphere. These reactions combine with internal dust, generating acidic impurities. This increases the oil's acidity, lowering its breakdown voltage and causing it to deteriorate. As impurity levels increase, the oil's color changes from clear to turbid. Furthermore, transformer oil readily absorbs moisture from the air during use, increasing its water content and significantly reducing its breakdown voltage, impacting its performance. Regular transformer oil replacement is essential to ensure proper operation of electrical equipment.

[0003] Waste transformer oil generated during electrical equipment maintenance isn't completely useless. Oxidized impurities and water only make up a small portion of the waste, while transformer oil remains the majority. To avoid environmental pollution and increased maintenance costs, the waste transformer oil can be decolorized and dehydrated to remove oxidized impurities and water, enabling its recycling and reuse. For example, patent CN104403775A discloses a waste transformer oil regeneration method. This method involves acid-washing and rinsing the waste transformer oil with alkali to remove acidic and alkaline impurities. The oil is then dried to remove water, ensuring its purity and performance. However, this patent utilizes chemical reactions to remove impurities from the waste transformer oil and thermal evaporation for dehydration, which produces secondary contaminants and fails to significantly reduce its moisture content. Therefore, implementing a controllable and recyclable physical decolorization and dehydration process on the waste transformer oil while avoiding the generation of secondary contaminants is crucial for improving waste transformer oil recovery efficiency and reducing recycling costs. Summary of the Invention

[0004] In order to avoid the generation of secondary pollutants during the recycling of waste transformer oil, increase the cost of recycling waste transformer oil, and reduce the efficiency, controllability and repeatability of the decolorization and dehydration of waste transformer oil, the present invention provides a decolorization and dehydration recycling method for waste transformer oil, which comprises the following steps:

[0005] S100: Identifying a first impurity characteristic of waste transformer oil and preliminarily setting operating parameters for the waste transformer oil in a decolorization process; identifying the impurity adsorption status of an adsorbent in the decolorization process and adjusting flow parameters of the waste transformer oil in the adsorbent;

[0006] S200: identifying the second impurity characteristics of the waste transformer oil after each decolorization process, performing adsorbent replacement, and re-adjusting the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements;

[0007] S300: Identifying the form of a dehydrating agent used in a dehydration process for waste transformer oil that meets decolorization requirements, obtaining water absorption properties of the dehydrating agent used in the dehydration process; and adjusting the dehydration process according to the water absorption properties.

[0008] Preferably, in S100, the first impurity characteristic of the waste transformer oil is identified, and the operating parameters of the waste transformer oil in the decolorization treatment process are preliminarily set, specifically:

[0009] Identify the impurity particle size distribution characteristics of the waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; wherein the impurity particle size distribution characteristics refer to the corresponding relationship between the impurity particle size and the impurity quantity in the waste transformer oil; and the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent;

[0010] According to the impurity particle size distribution characteristics and the microstructure characteristics, the impurity adsorption efficiency corresponding to the waste transformer oil passing through the adsorbent at different flow rates is estimated, thereby preliminarily setting the conveying flow rate of the waste transformer oil in the decolorization process.

[0011] Preferably, in S100, the impurity adsorption condition of the adsorbent in the decolorization process is identified, and the flow parameters of the waste transformer oil in the adsorbent are adjusted, specifically:

[0012] detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic;

[0013] The flow direction of the waste transformer oil in the adsorbent is adjusted according to the spatial distribution of the first region and the second region in the adsorbent.

[0014] Preferably, in S200, the second impurity characteristic of the waste transformer oil after each decolorization process is identified, and adsorbent replacement is performed; the operating parameters and the flow parameters are readjusted until the waste transformer oil meets the decolorization requirements, specifically:

[0015] Detecting impurity concentration data of the waste transformer oil after each decolorization process to obtain impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size distribution characteristics of impurities that are not removed after the waste transformer oil undergoes several decolorization processes;

[0016] According to the residual impurity characteristics, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size spatial distribution characteristic that matches the impurity particle size characteristics;

[0017] According to the impurity particle size distribution characteristics and the micropore size spatial distribution characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than a preset concentration threshold.

[0018] Preferably, in S300, the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements is identified, and the water absorption performance of the dehydrating agent used in the dehydration process is obtained; and the dehydration process is adjusted according to the water absorption performance, specifically as follows:

[0019] Detecting structural morphological data of dehydrating agents in all fixed beds within a dehydration process for waste transformer oil that meets decolorization conditions; wherein the structural morphological data includes the average pore size of the dehydrating agent's internal structure; and obtaining the water absorption performance of the dehydrating agents in all fixed beds based on the structural morphological data; wherein the water absorption performance refers to the volume of water that the dehydrating agents in the fixed beds can absorb per unit time;

[0020] The residence time of the waste transformer oil in each fixed bed during the dehydration process is adjusted according to the water absorption performance.

[0021] In another aspect, the present invention provides a waste transformer oil decolorization, dehydration and recovery treatment device, the device comprising the following modules:

[0022] a preliminary setting module for identifying a first impurity characteristic of the waste transformer oil and preliminarily setting operating parameters of the waste transformer oil in a decolorization treatment process;

[0023] a flow parameter adjustment module, configured to identify the impurity adsorption condition of the adsorbent in the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent;

[0024] An adsorbent replacement module is used to identify the second impurity characteristics of the waste transformer oil after each decolorization process and implement adsorbent replacement;

[0025] a decolorization adjustment module, configured to readjust the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements;

[0026] The absorption performance determination module is used to identify the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process;

[0027] The dehydration treatment adjustment module is used to adjust the dehydration treatment process according to the water absorption performance.

[0028] Preferably, the preliminary setting module is used to identify the first impurity feature of the waste transformer oil and preliminarily set the operating parameters of the waste transformer oil in the decolorization process, specifically:

[0029] Identify the impurity particle size distribution characteristics of the waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; wherein the impurity particle size distribution characteristics refer to the corresponding relationship between the impurity particle size and the impurity quantity in the waste transformer oil; and the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent;

[0030] According to the impurity particle size distribution characteristics and the microstructure characteristics, the impurity adsorption efficiency corresponding to the waste transformer oil passing through the adsorbent at different flow rates is estimated, thereby preliminarily setting the conveying flow rate of the waste transformer oil in the decolorization process.

[0031] Preferably, the flow parameter adjustment module is used to identify the impurity adsorption condition of the adsorbent in the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent, specifically:

[0032] detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic;

[0033] The flow direction of the waste transformer oil in the adsorbent is adjusted according to the spatial distribution of the first region and the second region in the adsorbent.

[0034] Preferably, the adsorbent replacement module is used to identify the second impurity characteristics of the waste transformer oil after each decolorization process and implement adsorbent replacement, specifically:

[0035] Detecting impurity concentration data of the waste transformer oil after each decolorization process to obtain impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size distribution characteristics of impurities that are not removed after the waste transformer oil undergoes several decolorization processes;

[0036] According to the residual impurity characteristics, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size spatial distribution characteristic that matches the impurity particle size characteristics;

[0037] The decolorization adjustment module is used to readjust the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements, specifically:

[0038] According to the impurity particle size distribution characteristics and the micropore size spatial distribution characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than a preset concentration threshold.

[0039] Preferably, the absorption performance determination module is used to identify the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process, specifically:

[0040] Detecting structural morphological data of dehydrating agents in all fixed beds within a dehydration process for waste transformer oil that meets decolorization conditions; wherein the structural morphological data includes the average pore size of the dehydrating agent's internal structure; and obtaining the water absorption performance of the dehydrating agents in all fixed beds based on the structural morphological data; wherein the water absorption performance refers to the volume of water that the dehydrating agents in the fixed beds can absorb per unit time;

[0041] The dehydration adjustment module is used to adjust the dehydration process according to the water absorption performance, specifically:

[0042] The residence time of the waste transformer oil in each fixed bed during the dehydration process is adjusted according to the water absorption performance.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] Identify the primary impurity characteristics of waste transformer oil and preliminarily set the operating parameters for the waste transformer oil bleaching process. Identify the impurity adsorption of the adsorbent within the bleaching process and adjust the flow parameters of the waste transformer oil within the adsorbent. In the actual bleaching process, given the impurity particle size distribution characteristics of the waste transformer oil and the microstructural characteristics of the adsorbent currently used in the bleaching process, estimate the impurity adsorption efficiency of the waste transformer oil at different flow rates through the adsorbent. The flow rate corresponding to the highest impurity adsorption efficiency is then set as the delivery rate for the waste transformer oil during the bleaching process. This ensures maximum impurity adsorption during a single flow of the waste transformer oil through the adsorbent, improving bleaching efficiency. To fully utilize the adsorbent's impurity adsorption performance, adjust the flow direction of the waste transformer oil within the adsorbent so that the waste transformer oil flows as much as possible through areas with high impurity adsorption performance.

[0045] After each decolorization step, the secondary impurity signature of the waste transformer oil is identified and the adsorbent is replaced. Operating and flow parameters are readjusted until the waste transformer oil meets decolorization requirements. To ensure that the replaced adsorbent effectively absorbs residual impurities in the waste transformer oil, an adsorbent with appropriate microstructural characteristics is selected to replace the adsorbent currently used in the decolorization step. This ensures that the replaced adsorbent efficiently absorbs residual impurities in the waste transformer oil, achieving thorough impurity adsorption and decolorization of the waste transformer oil, restoring the waste transformer oil from its original turbid state to a clear state.

[0046] The dehydrating agent morphology used in the dehydration process for waste transformer oil that meets decolorization requirements is identified to determine the dehydrating agent's water absorption performance. The dehydration process is then adjusted based on this water absorption performance. By examining the dehydrating agent's structural morphology, the real-time dehydration performance of the dehydrating agent can be quantitatively identified. Visual identification of the dehydrating agent in each fixed bed is performed to determine the average pore size of the dehydrating agent's internal microporous structure and the volume of water adsorbed per unit time by the dehydrating agent in each fixed bed. Based on the dehydrating agent's water absorption performance within each dehydration sub-unit, the pumps and valves in each dehydration sub-unit are controlled to adjust the flow of the waste transformer oil within each fixed bed. This adjusts the residence time of the waste transformer oil within each fixed bed during the dehydration process, ensuring sufficient contact between the waste transformer oil and the dehydrating agent and improving water absorption efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive efforts. Among them:

[0048] Figure 1 The present invention provides a flowchart of a method for decolorizing, dehydrating and recycling waste transformer oil.

[0049] Figure 2 This is a diagram of the equipment for the decolorization process.

[0050] Figure 3 It is the microstructure diagram of the adsorbent.

[0051] Figure 4 is a graph of the optical transmission characteristics of the first region within the adsorbent.

[0052] Figure 5 This is a color comparison chart of waste transformer oil after decolorization process.

[0053] Figure 6 This is a diagram of the equipment for the dehydration process.

[0054] Figure 7 It is a structural diagram of a waste transformer oil decolorization, dehydration and recovery treatment device provided by the present invention. DETAILED DESCRIPTION

[0055] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It will be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0056] The terms "comprise," "comprising," and "having," and any variations thereof, as used herein, are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product, or device comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or device.

[0057] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate 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.

[0058] See also Figure 1 As shown, the present invention provides a method for decolorizing, dehydrating and recycling waste transformer oil, which comprises the following steps:

[0059] S100, identifying the first impurity characteristics of the waste transformer oil and preliminarily setting the operating parameters of the waste transformer oil in the decolorization process; identifying the impurity adsorption status of the adsorbent in the decolorization process and adjusting the flow parameters of the waste transformer oil in the adsorbent.

[0060] Furthermore, the first impurity characteristics of the waste transformer oil are identified, and the operating parameters of the waste transformer oil in the decolorization process are preliminarily set, specifically:

[0061] Identify the impurity particle size distribution characteristics of waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; the impurity particle size distribution characteristics refer to the correspondence between the impurity particle size and the impurity quantity in the waste transformer oil; the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent;

[0062] According to the impurity particle size distribution characteristics and microstructural characteristics, the impurity adsorption efficiency corresponding to the waste transformer oil passing through the adsorbent at different flow rates is estimated, so as to preliminarily set the conveying flow rate of the waste transformer oil in the decolorization process.

[0063] Waste transformer oil undergoes oxidation reactions and combines with internal dust to produce impurities of corresponding particle sizes. These impurities diffuse and distribute within the waste transformer oil, making it appear turbid. The higher the impurity content in the waste transformer oil, the darker the color. The purpose of the decolorization process is to absorb the impurities in the waste transformer oil, reducing the impurity concentration to an acceptable value, and changing the waste transformer oil from turbid to clear. Figure 2 To implement a continuous decolorization process for waste transformer oil, equipment is used to absorb impurities within the waste transformer oil. Specifically, the decolorization equipment primarily includes a feed tank, a pump, valves, a fixed bed, and corresponding pipelines. The feed tank is loaded with waste transformer oil, which is pumped through the pipeline at a specific flow rate. The pump can be, but is not limited to, a double-plunger micropump, capable of precisely controlling the flow rate. A valve is also located downstream of the pump to control the flow state (e.g., flow rate) of the waste transformer oil within the pipeline. The fixed bed, the core component of the decolorization process, contains an adsorbent. The adsorbent's primary component can be, but is not limited to, activated clay, and its porous microstructure effectively absorbs impurities within the waste transformer oil. As the waste transformer oil flows into the fixed bed, it passes through the adsorbent, where it absorbs impurities, achieving decolorization.

[0064] Adsorbents rely on their internal porous microstructure to absorb impurities within waste transformer oil. The size of the adsorbent's porous microstructure directly influences its adsorption efficiency. Generally speaking, if the pore size (pore diameter) of the adsorbent's porous microstructure is smaller than the impurity particle size, the porous structure will not effectively adsorb impurities. Consequently, when the waste transformer oil flows through the adsorbent, the impurities will not be effectively filtered and adsorbed. Furthermore, the flow rate of the waste transformer oil through the adsorbent also affects the adsorbent's adsorption efficiency. The greater the flow rate, the shorter the contact time between impurities in the waste transformer oil and the adsorbent's porous microstructure, resulting in a loss of effective adsorption.

[0065] In order to ensure that the internal impurities of the waste transformer oil can be fully and quickly adsorbed into the porous microstructure when the waste transformer oil flows through the adsorbent, it is necessary to predict the adsorption of impurities by the porous microstructure under different flow rate conditions when the waste transformer oil flows through the adsorbent. To this end, the impurity particle size distribution characteristics of the waste transformer oil and the microstructural characteristics of the adsorbent currently used in the fixed bed of the decolorization process are first identified. Preferably, the laser scattering method can be used to detect the correspondence between the impurity particle size and the amount of impurities in the waste transformer oil, so as to obtain the impurity particle size distribution characteristics of the waste transformer oil; wherein, the correspondence between the impurity particle size and the amount of impurities refers to the amount of impurities in each impurity particle size range (such as 0.1-0.2μm, 0.2-0.3μm, 0.3-0.4μm, 0.4-0.5μm and other impurity particle size ranges). Preferably, the porous microstructure of the adsorbent can be detected by SEM (see Figure 3 ) and analyzed the SEM images of the adsorbent to obtain the spatial distribution characteristics of the micropore size within the adsorbent (i.e., the spatial distribution characteristics of the micropore size within the adsorbent). Analysis of the adsorbent's porous microstructure in the adsorption of impurities in waste transformer oil revealed that the adsorption efficiency of the porous microstructure is related to the impurity particle size distribution, the adsorbent's microstructural characteristics, and the flow rate of the waste transformer oil through the adsorbent. In an actual decolorization process, given the impurity particle size distribution characteristics of the waste transformer oil and the microstructural characteristics of the adsorbent currently used in the decolorization process, the corresponding impurity adsorption efficiency for waste transformer oil passing through the adsorbent at different flow rates is estimated. In other words, the corresponding adsorption ratio for waste transformer oil passing through the adsorbent at different flow rates is obtained. The flow rate corresponding to the highest impurity adsorption efficiency is then set as the delivery rate for the waste transformer oil in the decolorization process, ensuring maximum impurity adsorption during a single flow of waste transformer oil through the adsorbent and improving decolorization efficiency.

[0066] Furthermore, the impurity adsorption of the adsorbent in the decolorization process is identified, and the flow parameters of the waste transformer oil in the adsorbent are adjusted, specifically:

[0067] detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic;

[0068] The flow direction of the waste transformer oil in the adsorbent is adjusted according to the spatial distribution of the first area and the second area in the adsorbent.

[0069] As waste transformer oil is continuously pumped through the adsorbent, its porous microstructure continuously absorbs impurities, causing its adsorption performance to reach saturation and its efficiency in adsorbing impurities within the waste transformer oil to decrease. Given the three-dimensional shape of the adsorbent and the variable flow path of waste transformer oil within it, the adsorbent's regions with a greater probability of waste transformer oil flowing through them are more likely to absorb impurities, and their adsorption performance reaches saturation more quickly. This results in different regions within the adsorbent exhibiting varying impurity adsorption efficiencies. For example, after the same decolorization treatment duration, some regions within the adsorbent are saturated with impurities (i.e., no longer able to adsorb impurities), while other regions are not (i.e., still able to adsorb impurities).

[0070] Considering that the impurities in waste transformer oil have a specific color, after the adsorbent absorbs the impurities, the impurity accumulation area inside the adsorbent will also show a specific color. The change in the color of the adsorbent will simultaneously change the transmittance to light. Generally speaking, the more impurities adsorbed and accumulated in a certain area of the adsorbent, the smaller the transmittance to light of the corresponding area; the fewer impurities adsorbed and accumulated in a certain area of the adsorbent, the greater the transmittance to light of the corresponding area. Based on the relationship between the amount of impurities accumulated inside the adsorbent and the transmittance to light, the global optical transmittance characteristics of the adsorbent are synchronously detected during the implementation of the decolorization process, and the light transmittance change characteristics of all areas inside the adsorbent are obtained, thereby identifying and distinguishing the first area in the adsorbent that is in a saturated state of impurity adsorption and the second area that is not in a saturated state of impurity adsorption. Please refer to Figure 4 , it can be seen that the light transmittance of the first region within the adsorbent decreases over time. When a sufficient amount of impurities accumulate in the first region, the light transmittance of the first region drops to a minimum. Therefore, by analyzing the temporal variations in the light transmittance of all regions within the adsorbent, the first and second regions can be distinguished and calibrated. This analysis shows that the second region is not saturated with impurities and can continue to adsorb impurities from the waste transformer oil flowing through it. To fully utilize the adsorbent's impurity adsorption performance, the spatial distribution of the first and second regions within the adsorbent is used to determine the locations of all second regions within the adsorbent. This allows the flow direction of the waste transformer oil within the adsorbent to be adjusted, allowing as much waste transformer oil as possible to flow through the second regions, ensuring sufficient and rapid impurity adsorption. Preferably, multiple induced draft fans can be arranged within the fixed bed. By adjusting the on / off status and output speed of each induced draft fan, the flow path of the waste transformer oil within the adsorbent can be altered, ensuring that as much waste transformer oil as possible flows through the second regions, maximizing the impurity adsorption performance of the second regions.

[0071] S200, identifying the second impurity characteristics of the waste transformer oil after each decolorization process, performing adsorbent replacement, and re-adjusting operating parameters and flow parameters until the waste transformer oil meets the decolorization requirements.

[0072] Furthermore, the second impurity characteristics of the waste transformer oil after each decolorization process are identified, and the adsorbent is replaced; the operating parameters and flow parameters are readjusted until the waste transformer oil meets the decolorization requirements, specifically:

[0073] Detect impurity concentration data of the waste transformer oil after each decolorization process to obtain the impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size distribution characteristics of impurities that remain after the waste transformer oil has undergone several decolorization processes;

[0074] According to the characteristics of the impurity residues, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size spatial distribution characteristic that matches the impurity particle size characteristics;

[0075] According to the impurity particle size distribution characteristics and the micropore size spatial distribution characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than the preset concentration threshold.

[0076] Given the high impurity content in waste transformer oil and the limited impurity adsorption capacity of adsorbents, a single decolorization step cannot guarantee that the impurity content will be reduced to an acceptable level. To ensure the quality of recycled waste transformer oil, multiple decolorization steps are required. The above analysis shows that the adsorbent's adsorption performance for impurities is related to the pore size of the porous microstructure within the adsorbent and the impurity particle size. The adsorbent currently used in decolorization processes only effectively adsorbs impurities within a certain particle size range and is ineffective for impurities in other size ranges, resulting in impurities in other size ranges remaining in the waste transformer oil. Furthermore, after a single decolorization step, the adsorbent reaches adsorption saturation and is unable to adsorb further impurities, necessitating replacement of the adsorbent in the fixed bed.

[0077] To ensure that the replaced adsorbent effectively absorbs impurities remaining in the waste transformer oil, the impurity concentration data for the waste transformer oil after each decolorization step is output. The particle size distribution characteristics of impurities remaining in the waste transformer oil after several decolorization steps (i.e., the corresponding relationship between impurity particle size and impurity quantity) are then determined. This impurity particle size distribution, along with the relationship between the adsorption efficiency of the porous microstructure, the impurity particle size distribution, and the adsorbent's microstructural characteristics, are then combined to select an adsorbent with appropriate microstructural characteristics (i.e., the spatial distribution of micropore size within the adsorbent) to replace the adsorbent currently used in the decolorization step, ensuring that the replaced adsorbent effectively absorbs impurities remaining in the waste transformer oil. Furthermore, according to the process of step S100, after replacing the new adsorbent, the conveying flow rate of the waste transformer oil in the decolorization process is reset and adjusted, and the impurity adsorption of the adsorbent is identified during the decolorization process to readjust the flow direction of the waste transformer oil in the adsorbent. By repeatedly replacing the adsorbent and readjusting the conveying flow rate and flow direction of the waste transformer oil, until the impurity concentration of the waste transformer oil is lower than the preset concentration threshold, the waste transformer oil is thoroughly adsorbed and decolorized, and the waste transformer oil is restored from its original turbid state to a clear state (see Figure 5 ).

[0078] S300, identifying the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, obtaining the water absorption performance of the dehydrating agent used in the dehydration process; and adjusting the dehydration process according to the water absorption performance.

[0079] Furthermore, the dehydrating agent form of the waste transformer oil that meets the decolorization requirements in the dehydration process is identified, and the water absorption performance of the dehydrating agent used in the dehydration process is obtained; according to the water absorption performance, the dehydration process is adjusted, specifically as follows:

[0080] Detecting the structural morphology data of the dehydrating agents in all fixed beds within the dehydration process for waste transformer oil that meets decolorization requirements; the structural morphology data includes the average pore size of the dehydrating agent's internal structure; and obtaining the water absorption performance of the dehydrating agents in all fixed beds based on the structural morphology data; the water absorption performance refers to the volume of water that the dehydrating agent in the fixed bed can absorb per unit time.

[0081] According to the water absorption performance, the residence time of the waste transformer oil in each fixed bed during the dehydration process is adjusted.

[0082] Waste transformer oil absorbs atmospheric moisture, causing its own moisture content to increase. The purpose of the dehydration process is to absorb the moisture in the waste transformer oil, reduce the moisture content to an acceptable value, and restore the waste transformer oil to good insulation performance. Figure 6To dehydrate waste transformer oil, equipment is used to absorb moisture from the oil. Specifically, the dehydration process includes several serially connected dehydration sub-equipment. After decolorization, the waste transformer oil flows sequentially through all of the dehydration sub-equipment. Each dehydration sub-equipment absorbs moisture from the oil, effectively reducing its moisture content. Preferably, each dehydration sub-equipment includes a pump, a valve, and a fixed bed along the flow direction of the waste transformer oil. The pump can be, but is not limited to, a double-plunger micropump capable of precisely controlling the flow rate. The valve controls the flow state (e.g., flow rate) of the waste transformer oil within the pipeline. The fixed bed, the core component of the dehydration sub-equipment, contains a dehydrating agent. The dehydrating agent's primary components can be, but are not limited to, calcium oxide, bentonite, and resin. The dehydrating agent has a porous microstructure capable of absorbing moisture from the waste transformer oil. As the waste transformer oil flows into the fixed bed, it passes through the dehydrating agent, where it absorbs moisture, effectively dehydrating the waste transformer oil.

[0083] Dehydrating agents utilize their internal porous microstructure and their inherent water absorption and expansion properties to absorb moisture from waste transformer oil. The size of the dehydrating agent's porous microstructure directly influences its water absorption efficiency. Generally speaking, the greater the number of micropores within the dehydrating agent, the larger its specific surface area, and the higher its water absorption efficiency. Furthermore, the longer the waste transformer oil resides within the dehydrating agent as it flows through it, the more thorough its contact with the dehydrating agent, resulting in a greater amount of water absorbed. After absorbing moisture from the waste transformer oil, the dehydrating agent expands, causing its internal micropore structure to contract. This results in a decrease in the number of micropores and specific surface area, and a corresponding decrease in its water absorption performance. By examining the dehydrating agent's structural morphology, it is possible to quantitatively identify the dehydrating agent's real-time dehydration performance. To this end, visual inspection was performed on the dehydrating agents in each fixed bed to determine the average pore size of the dehydrating agent's internal micropores. This was used to determine the volume of water adsorbed per unit time by each dehydrating agent in each fixed bed. The greater the volume of water that the dehydrating agent can absorb per unit time, the higher the water absorption performance of the dehydrating agent.

[0084] Each dehydration sub-unit within the dehydration process operates independently, utilizing its own pumps and valves to adjust the flow rate and volume of the waste transformer oil. This results in differences in the water absorption performance of the dehydrating agents within each dehydration sub-unit, resulting in some dehydrating agents having higher water absorption performance, while others have lower performance. Generally speaking, the water absorption performance of dehydrating agents in dehydration sub-units located closer to the upstream end decreases more rapidly, while that of dehydrating agents located closer to the downstream end decreases more slowly. To maximize water absorption across all dehydrating sub-units, the pumps and valves within each dehydration sub-unit are controlled based on the dehydrating agent's water absorption performance, altering the flow pattern of the waste transformer oil within each fixed bed. This, in turn, adjusts the residence time of the waste transformer oil within each fixed bed during the dehydration process, ensuring sufficient contact between the waste transformer oil and the dehydrating agent and improving water absorption efficiency.

[0085] See also Figure 7 As shown, the present invention provides a waste transformer oil decolorization, dehydration and recovery treatment device, which includes the following modules:

[0086] A preliminary setting module, used to identify the first impurity characteristics of the waste transformer oil and preliminarily set the operating parameters of the waste transformer oil in the decolorization process;

[0087] The flow parameter adjustment module is used to identify the impurity adsorption status of the adsorbent during the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent;

[0088] Adsorbent replacement module, used to identify the secondary impurity characteristics of waste transformer oil after each decolorization process and implement adsorbent replacement;

[0089] Decolorization treatment adjustment module, used to readjust operating parameters and flow parameters until the waste transformer oil meets the decolorization requirements;

[0090] The absorption performance determination module is used to identify the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process;

[0091] The dehydration treatment adjustment module is used to adjust the dehydration treatment process according to the water absorption performance.

[0092] Furthermore, the preliminary setting module is used to identify the first impurity feature of the waste transformer oil and preliminarily set the operating parameters of the waste transformer oil in the decolorization process, specifically:

[0093] Identify the impurity particle size distribution characteristics of waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; the impurity particle size distribution characteristics refer to the correspondence between the impurity particle size and the impurity quantity in the waste transformer oil; the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent;

[0094] According to the impurity particle size distribution characteristics and microstructural characteristics, the impurity adsorption efficiency corresponding to the waste transformer oil passing through the adsorbent at different flow rates is estimated, so as to preliminarily set the conveying flow rate of the waste transformer oil in the decolorization process.

[0095] Furthermore, the flow parameter adjustment module is used to identify the impurity adsorption status of the adsorbent in the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent, specifically:

[0096] detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic;

[0097] The flow direction of the waste transformer oil in the adsorbent is adjusted according to the spatial distribution of the first area and the second area in the adsorbent.

[0098] Furthermore, the adsorbent replacement module is used to identify the second impurity characteristics of the waste transformer oil after each decolorization process and implement adsorbent replacement, specifically:

[0099] Detect impurity concentration data of the waste transformer oil after each decolorization process to obtain the impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size distribution characteristics of impurities that remain after the waste transformer oil has undergone several decolorization processes;

[0100] According to the characteristics of the impurity residues, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size spatial distribution characteristic that matches the impurity particle size characteristics;

[0101] The decolorization treatment adjustment module is used to readjust the operating parameters and flow parameters until the waste transformer oil meets the decolorization requirements. Specifically:

[0102] According to the impurity particle size distribution characteristics and the micropore size spatial distribution characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than the preset concentration threshold.

[0103] Furthermore, the absorption performance determination module is used to identify the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process, specifically:

[0104] Detecting the structural morphology data of the dehydrating agents in all fixed beds within the dehydration process for waste transformer oil that meets decolorization requirements; the structural morphology data includes the average pore size of the dehydrating agent's internal structure; and obtaining the water absorption performance of the dehydrating agents in all fixed beds based on the structural morphology data; the water absorption performance refers to the volume of water that the dehydrating agent in the fixed bed can absorb per unit time.

[0105] The dehydration adjustment module is used to adjust the dehydration process according to the water absorption performance, specifically:

[0106] According to the water absorption performance, the residence time of the waste transformer oil in each fixed bed during the dehydration process is adjusted.

[0107] The operation and effect of the waste transformer oil decolorization, dehydration and recovery treatment device of the present invention are corresponding to and consistent with the above-mentioned waste transformer oil decolorization, dehydration and recovery treatment method, and the waste transformer oil decolorization, dehydration and recovery treatment device will not be repeated here.

[0108] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by adding the necessary general-purpose hardware platform, or of course, by combining hardware and software. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a computer product. The present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it, and other embodiments may also be used. Although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for decolorizing, dehydrating and recycling waste transformer oil, characterized in that: The method comprises the following steps: S100: Identify the first impurity characteristics of the waste transformer oil and preliminarily set the operating parameters of the waste transformer oil in the decolorization process, which are specifically: Identify the impurity particle size distribution characteristics of the waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; wherein the impurity particle size distribution characteristics refer to the corresponding relationship between the impurity particle size and the impurity quantity in the waste transformer oil; and the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent; According to the impurity particle size distribution characteristics and the microstructural characteristics, the impurity adsorption efficiency corresponding to each of the waste transformer oil passing through the adsorbent at different flow rates is estimated, thereby preliminarily setting the conveying flow rate of the waste transformer oil in the decolorization process; Identify the impurity adsorption condition of the adsorbent in the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent, which is specifically: detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic; adjusting the flow direction of the waste transformer oil in the adsorbent according to the spatial distribution of the first and second regions in the adsorbent, and changing the flow path of the waste transformer oil in the adsorbent by adjusting the on / off state and output wind speed of the induced draft fan to ensure that the waste transformer oil flows through the second region; S200: identifying the second impurity characteristics of the waste transformer oil after each decolorization process, performing adsorbent replacement, and re-adjusting the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements; S300: Identify the form of the dehydrating agent used in the dehydration process of the waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process; adjust the dehydration process according to the water absorption performance, which is specifically as follows: Detecting structural morphology data of dehydrating agents in all fixed beds within a dehydration process for waste transformer oil that meets decolorization conditions; wherein the structural morphology data includes an average pore size of the dehydrating agent's internal structure; and obtaining water absorption performance of the dehydrating agents in all fixed beds based on the structural morphology data; wherein the water absorption performance refers to the volume of water that can be absorbed per unit time by the dehydrating agents in the fixed beds; According to the water absorption performance of the dehydrating agent in each dehydration treatment sub-equipment, the pump and valve of each dehydration treatment sub-equipment are controlled to change the flow state of the waste transformer oil in each fixed bed, thereby adjusting the residence time of the waste transformer oil in each fixed bed during the dehydration treatment process.

2. The method according to claim 1, characterized in that In S200, the second impurity characteristic of the waste transformer oil after each decolorization process is identified, and adsorbent replacement is performed; the operating parameters and the flow parameters are readjusted until the waste transformer oil meets the decolorization requirements, specifically: Detecting impurity concentration data of the waste transformer oil after each decolorization process to obtain impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size characteristics of impurities that are not removed after the waste transformer oil undergoes several decolorization processes; According to the residual impurity characteristics, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size characteristic that matches the impurity particle size characteristics; According to the impurity particle size characteristics and the micropore size characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than a preset concentration threshold.

3. A waste transformer oil decolorization, dehydration and recovery treatment device, characterized in that: The device comprises the following modules: The preliminary setting module is used to identify the first impurity characteristics of the waste transformer oil and preliminarily set the operating parameters of the waste transformer oil in the decolorization process, which are specifically: Identify the impurity particle size distribution characteristics of the waste transformer oil and the microstructure characteristics of the adsorbent currently used in the decolorization process; wherein the impurity particle size distribution characteristics refer to the corresponding relationship between the impurity particle size and the impurity quantity in the waste transformer oil; and the microstructure characteristics refer to the spatial distribution characteristics of the micropore size in the adsorbent; According to the impurity particle size distribution characteristics and the microstructural characteristics, the impurity adsorption efficiency corresponding to each of the waste transformer oil passing through the adsorbent at different flow rates is estimated, thereby preliminarily setting the conveying flow rate of the waste transformer oil in the decolorization process; The flow parameter adjustment module is used to identify the impurity adsorption condition of the adsorbent in the decolorization process and adjust the flow parameters of the waste transformer oil in the adsorbent, which is specifically: detecting a global optical transmission characteristic of the adsorbent during the decolorization process, and identifying a first region in the adsorbent that is saturated with impurities and a second region that is not saturated with impurities based on the global optical transmission characteristic; adjusting the flow direction of the waste transformer oil in the adsorbent according to the spatial distribution of the first and second regions in the adsorbent, and changing the flow path of the waste transformer oil in the adsorbent by adjusting the on / off state and output wind speed of the induced draft fan to ensure that the waste transformer oil flows through the second region; An adsorbent replacement module is used to identify the second impurity characteristics of the waste transformer oil after each decolorization process and implement adsorbent replacement; a decolorization adjustment module, configured to readjust the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements; The absorption performance determination module is used to identify the dehydrating agent form in the dehydration process of waste transformer oil that meets the decolorization requirements, and obtain the water absorption performance of the dehydrating agent used in the dehydration process, which is specifically: Detecting structural morphology data of dehydrating agents in all fixed beds within a dehydration process for waste transformer oil that meets decolorization conditions; wherein the structural morphology data includes an average pore size of the dehydrating agent's internal structure; and obtaining water absorption performance of the dehydrating agents in all fixed beds based on the structural morphology data; wherein the water absorption performance refers to the volume of water that can be absorbed per unit time by the dehydrating agents in the fixed beds; The dehydration treatment adjustment module is used to adjust the dehydration treatment process according to the water absorption performance. Specifically, the module controls the pump and valve of each dehydration treatment sub-equipment according to the water absorption performance of the dehydrating agent in each dehydration treatment sub-equipment to change the flow state of the waste transformer oil in each fixed bed, thereby adjusting the residence time of the waste transformer oil in each fixed bed during the dehydration treatment process.

4. The device according to claim 3, characterized in that The adsorbent replacement module is used to identify the second impurity characteristics of the waste transformer oil after each decolorization process and implement adsorbent replacement, specifically: Detecting impurity concentration data of the waste transformer oil after each decolorization process to obtain impurity residual characteristics of the waste transformer oil; wherein the impurity residual characteristics refer to the particle size characteristics of impurities that are not removed after the waste transformer oil undergoes several decolorization processes; According to the residual impurity characteristics, the adsorbent used in the decolorization process is replaced so that the replaced adsorbent has a micropore size characteristic that matches the impurity particle size characteristics; The decolorization adjustment module is used to readjust the operating parameters and the flow parameters until the waste transformer oil meets the decolorization requirements, specifically: According to the impurity particle size characteristics and the micropore size characteristics, the conveying flow rate of the waste transformer oil in the next decolorization treatment process and the flow direction in the adsorbent are readjusted until the impurity concentration of the waste transformer oil is lower than a preset concentration threshold.

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