Method and system for automatically adjusting temperature and humidity of bio-oil storage tank

Abstract

The present application belongs to the technical field of adjusting system of oil storage tank, and particularly relates to a kind of biological oil storage tank temperature and humidity automatic regulating method and system, its method includes: obtaining the operation data of storage tank conveying equipment and current oil temperature, and constructing flow resistance index;Establish the integral mechanism with time as the axis, according to the current oil temperature and the preset sampling period, the cumulative thermal stress of oil in the whole life cycle is calculated, and the cumulative thermal stress is used to represent the total heat damage of oil during storage;Based on the flow resistance index and the cumulative thermal stress, the target temperature at the current time is calculated;Collect the relative humidity and the ambient temperature, and the target temperature is corrected according to the relative humidity and the ambient temperature, and the corrected temperature is used as the final set value to carry out closed loop control on the storage tank.The present application can adaptively adjust the heating strategy according to the flow resistance and cumulative thermal stress of oil, and actively prevent in high humidity environment.

Description

Technical Field

[0001] This invention relates to the technical field of temperature and humidity control systems for oil storage tanks. More specifically, this invention relates to an automatic temperature and humidity control method and system for bio-oil storage tanks. Background Technology

[0002] In the field of bioenergy and chemical engineering, bio-oils are important raw materials, and their storage management directly affects the stability of subsequent production and product quality. Current tank temperature control systems mainly employ fixed-value PID control or simple on-off control. This traditional control logic typically relies on operators setting a fixed heating temperature based on experience. When the value detected by a single-point temperature sensor inside the tank is lower than the set value, the heating system is activated; when it is higher than the set value, heating is stopped.

[0003] However, the sources of bio-oil raw materials are complex, and different batches of oil vary greatly in rheological properties such as viscosity and pour point. For low-viscosity oils, conventional temperature settings may lead to overheating and unnecessary waste. For high-viscosity oils, the temperature may not be sufficient to ensure pump flowability, resulting in pipe blockage or pump cavitation. Furthermore, existing technologies often neglect the cumulative loss of thermal life. Bio-oils contain a large amount of unsaturated fatty acids and are quite sensitive to heat. Traditional methods only focus on whether the instantaneous temperature meets the standard, ignoring the storage time of the batch of oil at high temperatures. As the heating time accumulates, the antioxidant capacity of the oil will decrease, and maintaining high temperatures for a long time will accelerate the rancidity of the oil and lead to excessive peroxide value.

[0004] Furthermore, existing control systems generally lack temperature and humidity coupling control mechanisms. During rainy seasons or in high-humidity environments, the air circulation system of storage tanks is prone to absorbing moisture. Without proactive control logic to prevent condensate backflow, condensate can easily form inside the tank, leading to microbial growth and severely impacting the quality of raw materials. Therefore, how to dynamically adjust the storage temperature based on the real-time rheological characteristics and thermal life of the oils, and combine this with defensive control based on ambient humidity, is a pressing technical problem that needs to be solved. Summary of the Invention

[0005] To address the problems existing in the traditional control methods for bio-oil storage tanks, this invention provides an automatic temperature and humidity regulation method and system for bio-oil storage tanks. This system can adaptively adjust the heating strategy based on the rheological resistance and cumulative thermal lifetime of the oil, and proactively defend against high humidity environments.

[0006] In a first aspect, the present invention provides an automatic temperature and humidity regulation method for a bio-oil storage tank, comprising: acquiring operating data of the tank conveying equipment and the current oil temperature; constructing a rheological resistance index based on the operating data and the current oil temperature, wherein the rheological resistance index is used to characterize the real-time viscosity state of the oil; establishing an integral mechanism with time as the axis, calculating the cumulative thermal stress of the oil over its entire life cycle based on the current oil temperature and a preset sampling period, wherein the cumulative thermal stress is used to characterize the total thermal damage suffered by the oil during storage; calculating the target temperature at the current moment using an adaptive target temperature decision model based on the rheological resistance index and the cumulative thermal stress, wherein the adaptive target temperature decision model is used to balance the rheological resistance index and the cumulative thermal stress; collecting ambient relative humidity and ambient temperature, performing environmental coupling correction on the target temperature based on the ambient relative humidity and ambient temperature, and using the corrected temperature as the final set value for closed-loop control of the storage tank.

[0007] This invention constructs a rheological resistance index, which can accurately sense the viscosity differences of bio-oils without increasing the cost of online viscometers, and accurately assess the current transport resistance. This avoids overheating of low-viscosity oils, thereby significantly improving average energy efficiency. Furthermore, this invention establishes a thermal life profile for bio-oils by calculating cumulative thermal stress. This measure accurately reflects the gradual aging of bio-oils over storage time, overcoming the shortcomings of existing technologies that only focus on instantaneous temperature and ignore historical thermal damage, providing crucial lifespan data for subsequent temperature control decisions. Moreover, this invention incorporates an environmental coupling correction mechanism. In high-humidity environments, this mechanism actively raises the oil temperature slightly above the ambient temperature, forming a slightly positive pressure hot gas layer within the storage tank, disrupting condensation conditions. This effectively prevents moisture drawn in by the breather valve from condensing into water droplets on the inner wall of the tank top, thereby inhibiting microbial growth and ensuring raw material quality.

[0008] Preferably, the rheological drag index satisfies the following relationship:

[0009]

[0010] in, The rheological drag index; This is the normalized proportionality coefficient; This refers to the real-time operating torque current of the delivery pump motor; The instantaneous flow rate within the pipe; To prevent division by zero constant; This is the current measured oil temperature; This is the reference temperature.

[0011] This invention, by constructing a specific calculation formula for the rheological resistance index, can comprehensively utilize multi-source data such as the real-time operating torque current of the delivery pump motor, the instantaneous flow rate in the pipeline, and the current measured oil temperature to achieve indirect and accurate perception of the real-time viscosity state of bio-oils. The specific calculation formula for the rheological resistance index uses the unit flow energy consumption cost represented by the ratio of current to flow rate as its core element. This core indicator can intuitively characterize the magnitude of resistance encountered during transportation. Simultaneously, the formula introduces a temperature correction factor, which is composed of the ratio of the current measured oil temperature to a reference temperature. This factor allows for dynamic compensation for changes in physical resistance caused by temperature variations, thereby ensuring that the rheological resistance index maintains accuracy and stability under different operating conditions. This invention effectively overcomes the drawbacks of traditional one-size-fits-all temperature control methods caused by the large viscosity differences of bio-oils. The system can automatically identify high-viscosity bio-oils based on the rheological resistance index and specifically strengthen heating measures to ensure smooth transportation; at the same time, it can also accurately identify low-viscosity bio-oils, avoiding energy waste caused by overheating.

[0012] Preferably, the accumulated thermal stress satisfies the following relationship:

[0013]

[0014] in, This represents the total cumulative thermal stress borne by the grease in the storage tank up to time t. This represents the total number of samples taken from the time the data was entered into the database until the current time. The temperature of the oil inside the tank recorded during the k-th sampling; This is the safe reference temperature for oil oxidation. This represents the sampling time interval.

[0015] This invention uses the safe oxidation reference temperature of oils as a benchmark and cleverly employs the square of the temperature ratio to approximate the nonlinear acceleration characteristics of the oxidation reaction rate. This approach achieves a weighted cumulative calculation of thermal damage during high-temperature periods, thereby constructing a time-based integral mechanism. This mechanism can accurately and continuously characterize the total thermal damage suffered by bio-oils due to temperature throughout the entire storage period. During system operation, the accumulated thermal stress value is updated in real time. Based on this continuously updated data, the system can construct dynamic thermal life profiles for different batches of bio-oils. Existing technologies often only focus on instantaneous temperature, neglecting the impact of historical thermal accumulation on bio-oils. This invention provides crucial and accurate data support for subsequent operations such as adaptively adjusting target temperatures, slowing down the aging process of oils, and inhibiting the growth of peroxide value, thus significantly extending the safe storage life of bio-oils and greatly improving the stability of raw material quality.

[0016] Preferably, the target temperature satisfies the following relationship:

[0017]

[0018] in, The target temperature setpoint calculated for the current moment; To maintain the basic insulation temperature to prevent the grease from solidifying; The maximum allowable temperature rise range; The hyperbolic tangent function value of the rheological drag index; The preset thermal life rating; This represents the total accumulated thermal stress at the current moment.

[0019] This invention innovatively introduces an adaptive target temperature decision model. This model uses the base insulation temperature and the maximum allowable temperature rise as core benchmark parameters. In actual operation, it cleverly utilizes the hyperbolic tangent function value of the rheological resistance index to accurately respond to real-time heating demands. This response mechanism can flexibly adjust the heating strategy based on the real-time state of the bio-oil, ensuring that the heating process meets delivery requirements without overheating and causing thermal damage. The saturation characteristics of the hyperbolic tangent function play a crucial role in soft limiting. When the sensor malfunctions, this characteristic effectively prevents the temperature setpoint from going out of control, avoiding irreversible damage to the bio-oil due to abnormal temperature increases, and providing reliable assurance for the quality and safety of the bio-oil. Even in the later stages of bio-oil storage, when the fluidity requirement remains high, the system will automatically lower the target temperature based on this coefficient, prioritizing the protection of already heat-aged bio-oil to prevent further deterioration and extend its effective service life.

[0020] Preferably, the environmental coupling correction of the target temperature based on the relative humidity and ambient temperature includes: determining whether the relative humidity is greater than a high humidity threshold; if the relative humidity is greater than the high humidity threshold and the current measured oil temperature is less than the ambient temperature, then comparing the target temperature with the sum of the ambient temperature and a preset temperature difference, and selecting the larger value as the corrected target temperature to form a slightly positive pressure hot air layer in the tank, thereby disrupting the condensation conditions; if the relative humidity is not greater than the high humidity threshold, or the current measured oil temperature is not less than the ambient temperature, then directly using the target temperature as the final set value.

[0021] This invention introduces an environmental coupling correction mechanism to form a micro-positive pressure hot gas layer inside the bio-oil storage tank and disrupt condensation conditions. This effectively prevents moisture drawn in by the breathing valve from condensing into water droplets on the inner wall of the top of the bio-oil storage tank, thereby achieving the beneficial effects of inhibiting microbial growth and ensuring the quality of bio-oil raw materials.

[0022] Preferably, the closed-loop control of the storage tank includes: increasing the heating output power when the feedback value is lower than the final set value; and reducing or stopping the heating output and relying on the natural heat dissipation of the storage tank when the feedback value is higher than the final set value, so that the temperature of the grease in the storage tank approaches the final set value.

[0023] Preferably, the acquisition of operating data of the tank conveying equipment includes: reading the output torque current of the motor in real time through the frequency converter communication interface of the tank conveying pump; reading the instantaneous flow rate in real time through a mass flow meter or electromagnetic flow meter installed on the pipeline; and reading the current measured oil temperature through a temperature transmitter installed at the bottom of the tank.

[0024] Preferably, the normalization ratio is used to adjust the current-to-flow ratio of pumps with different power to a preset range.

[0025] Preferably, in the adaptive target temperature decision model, the hyperbolic tangent function is used to perform a mathematical soft limiting effect by utilizing its saturation characteristics, so as to prevent the calculated temperature from exceeding the safe range when the rheological drag index becomes infinite due to sensor failure.

[0026] Secondly, the present invention provides an automatic temperature and humidity control system for a bio-oil storage tank, comprising a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the above-mentioned automatic temperature and humidity control method for a bio-oil storage tank is implemented.

[0027] By adopting the above technical solution, a computer program for the above-mentioned method of automatic temperature and humidity regulation of biological oil storage tank is generated and stored in a memory so that it can be loaded and executed by a processor. A terminal device can then be made based on the memory and the processor for convenient use.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention proposes an automatic temperature and humidity control method for bio-oil storage tanks based on rheological resistance feedback and thermal life decay model. This method uses pumping resistance as the driving force for heating and the accumulation of thermal stress as the resistance to heating, thereby finding the optimal real-time temperature control point through the dynamic game between the two.

[0030] Furthermore, by introducing a life decay mechanism, the upper limit of the storage tank temperature automatically decreases with storage time, thereby effectively reducing the growth rate of peroxide value of bio-oils and extending the storage life of bio-oils. At the same time, by constructing a rheological resistance index, the present invention achieves accurate viscosity sensing in the absence of an online viscometer and achieves the best balance between energy consumption and transportation efficiency. Attached Figure Description

[0031] Figure 1This is a flowchart illustrating an automatic temperature and humidity control method for a bio-oil storage tank according to the present invention;

[0032] Figure 2 This is a schematic diagram showing a comparison curve between the prior art and the temperature control strategy of the present invention in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram illustrating the dynamic relationship between the cumulative thermal stress value and the upper limit of temperature control in an embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0035] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] This invention discloses an automatic temperature and humidity control method for bio-oil storage tanks, referring to... Figure 1 This includes steps S1-S4:

[0037] S1. Obtain the operating data and current oil temperature of the storage tank conveying equipment. Construct a rheological resistance index based on the operating data and current oil temperature. The rheological resistance index is used to characterize the real-time viscosity of the oil.

[0038] In an optional embodiment, when it is necessary to obtain the operating data and current oil temperature of the tank conveying equipment, the output torque current of the motor is read in real time through the inverter communication interface of the tank conveying pump. Instantaneous flow rate is read by a flow meter on the pipeline. The current oil temperature is read by a temperature transmitter installed at the bottom of the storage tank. Under ideal low viscosity conditions, a relatively small current can drive the grease to flow and generate a large flow rate. However, under high viscosity conditions, a larger torque current is required to drive the grease to flow at the same flow rate. Therefore, the ratio of the motor's output torque current to the instantaneous flow rate in the pipeline is used as the basic characterization of physical resistance.

[0039] To further assess the true rheological properties of oils and fats by combining thermodynamic state, a rheological drag index calculation model including a temperature correction term is constructed. The rheological drag index satisfies the following relationship:

[0040]

[0041] in, This is a dimensionless rheological resistance index. The larger the value, the worse the oil's fluidity and the more urgent the heating requirement under the current operating conditions. It is a normalization proportional coefficient used to adjust the current-to-flow ratio of pumps with different power to a preset range to match the input requirements of the control algorithm. This refers to the real-time operating torque current of the delivery pump motor; The instantaneous flow rate within the pipe; To prevent the division by zero constant, its design aims to prevent calculation errors where the denominator is 0 when the pump starts up or when a complete blockage occurs, resulting in a flow rate of 0, thereby ensuring the stability of the mathematical operations of the control system. This is the current measured oil temperature; This is the reference temperature.

[0042] Specifically, the logical relationship in the rheological drag index calculation model is as follows: the first term of the formula... The ratio of current to flow rate directly characterizes the energy cost per unit flow rate, intuitively reflecting the real-time physical transport resistance of grease in the pipeline; a temperature correction factor with temperature as the variable is introduced in the latter part of the formula. Its physical significance lies in establishing a dynamic evaluation benchmark under thermal operating conditions. During normal heating and transportation, the increase in oil temperature naturally leads to a decrease in the physical viscosity of the grease, which in turn significantly reduces the current-to-flow ratio. At this time, the introduction of a temperature correction factor can provide a weighted correction for the decrease in resistance value caused solely by the increase in temperature, preventing the rheological resistance index from falling too quickly and causing the control system to prematurely determine that the oil meets the standard and interrupt heating. When the system is in an abnormal state, that is, the oil temperature has increased but the viscosity of the grease in the storage tank remains high, the increased temperature correction factor will be superimposed on the high current-to-flow ratio to calculate a higher rheological resistance index to highlight the abnormal state.

[0043] In this way, by constructing this rheological resistance index, the system can keenly sense the inherent viscosity differences of different batches of raw materials without increasing the cost of online viscometers, accurately assess the current conveying resistance, and formulate appropriate heating strategies, thereby avoiding overheating of low-viscosity oils and significantly improving average energy-saving efficiency.

[0044] S2. Establish an integral mechanism based on time, calculate the cumulative thermal stress of the oil throughout its entire life cycle according to the current oil temperature and the preset sampling period. The cumulative thermal stress is used to characterize the total thermal damage suffered by the oil during storage.

[0045] In an optional embodiment, the system establishes a time-based integration mechanism and creates a thermal life profile for the batch of oil. Starting from the time the oil enters the tank, the system calculates the thermal damage increment at the current temperature every fixed sampling period and adds it to the cumulative thermal stress. The cumulative thermal stress satisfies the following relationship:

[0046]

[0047] in, This represents the cumulative thermal stress borne by the grease in the container up to the current time t. This represents the total number of samples taken from the time the data was entered into the database until the current time. The temperature of the oil inside the tank recorded during the k-th sampling; This is the safe reference temperature for oil oxidation; below this temperature, oxidation is extremely slow. This represents the sampling time interval.

[0048] Specifically, the logical relationship of the cumulative thermal stress calculation model is as follows: Although the oxidation rate of oils exhibits a complex nonlinear acceleration characteristic with increasing temperature, this model utilizes the square term of the temperature ratio. This formula effectively approximates this nonlinear damage trend, using the safe reference temperature for oil oxidation as a normalization point. When the actual oil temperature is close to this reference temperature, the cumulative thermal stress increases relatively slowly. However, when the actual oil temperature exceeds this reference temperature, the temperature ratio is greater than 1 and amplified by the square term, resulting in a significant superlinear increase in thermal damage. This calculation method scientifically assigns a greater penalty weight to high-temperature periods, which on the one hand can fully record the baseline thermal accumulation caused by long-term storage, and on the other hand, focuses on capturing the severe thermal shock caused by short-term overheating.

[0049] To more clearly illustrate the effect and calculation method of accumulated thermal stress, a calculation example is given:

[0050] Assume the system performs one sampling, and the sampling time interval is... The oil temperature recorded during this sampling period was 1 hour. 70 degrees Celsius is the safe reference temperature for oil oxidation. The temperature is 35 degrees Celsius.

[0051] Calculate the thermal damage increment for this sampling period. :

[0052]

[0053] If the previously accumulated thermal stress was 100, then the updated .

[0054] In this way, by updating the accumulated thermal stress value in real time, the system can digitally couple the physical storage time of oil with its chemical thermal history, thereby making up for the shortcomings of existing technologies that only focus on instantaneous temperature and ignore historical thermal damage, and providing key life dimension data for subsequent adaptive reduction of target temperature to delay aging.

[0055] S3. Based on the rheological drag index and cumulative thermal stress, the target temperature at the current moment is calculated using an adaptive target temperature decision model. The adaptive target temperature decision model is used to balance the rheological drag index and cumulative thermal stress.

[0056] In an optional embodiment, the system no longer uses a fixed setpoint, but instead calculates the optimal target temperature at the current moment by combining the rheological drag index and accumulated thermal stress. The optimal target temperature at the current moment satisfies the following relationship:

[0057]

[0058] in, The calculated target temperature setpoint is output to the PLC for temperature control. To maintain the basic insulation temperature to prevent the grease from solidifying; The maximum allowable temperature rise range; The hyperbolic tangent function of the rheological drag index has a range of values. ; The preset thermal life rating; This represents the total accumulated thermal stress at the current moment. This is the lifetime decay coefficient.

[0059] When calculating the target temperature, the hyperbolic tangent function term responds to thermodynamics. As the rheological resistance exponent increases, the function value tends towards 1, thus increasing the target temperature. The purpose of using the hyperbolic tangent function is to leverage its saturation characteristics to provide a mathematical soft limit, preventing the calculated temperature from exceeding the safe range when the rheological resistance exponent becomes infinitely large due to sensor malfunction. The lifetime decay coefficient term responds to heating resistance. In the early stages of grease storage, the accumulated thermal stress is small, and this coefficient is close to 1, allowing the system to fully heat the grease to ensure efficient transport. In the later stages of storage, the accumulated thermal stress increases, and this coefficient is significantly less than 1. At this point, even if the rheological resistance exponent is large, the calculated target temperature will be lowered, thus meeting the full heating requirements of new grease and protecting older grease.

[0060] To more clearly illustrate the role and calculation method of the target temperature at the current moment, a calculation example is given:

[0061] Assuming basic insulation temperature The maximum allowable temperature rise is 30 degrees Celsius. 25 degrees Celsius, rated thermal life It is 1000.

[0062] Under the condition that the oil in the storage tank is new oil, i.e., the rheological resistance index The value is 1, representing the accumulated thermal stress at the current moment. If the value is extremely small and negligible, the target temperature is calculated as follows:

[0063]

[0064] When the oil in the storage tank is old oil, i.e., the rheological resistance index It remains at 1, but the accumulated thermal stress at the current moment If the temperature has reached 1000, the target temperature is calculated as follows:

[0065]

[0066] It can be seen that, under the same grease viscosity and resistance, due to the accumulation of thermal stress, the target temperature automatically decreased from 49.04 degrees Celsius to 39.52 degrees Celsius, thus protecting the aged grease.

[0067] Thus, through the adaptive target temperature decision model, the system implements a phased process strategy. When the oil ages, the system automatically lowers the upper limit of the target temperature to prevent the oil with existing heat damage from being subjected to high temperatures. This sacrifices part of the delivery rate within the range allowed by physical rheology in exchange for the safety of the oil's chemical properties, effectively extending the storage life of bio-oils and improving the inherent safety of the system.

[0068] S4. Collect ambient relative humidity and ambient temperature, perform environmental coupling correction on the target temperature based on the ambient relative humidity and ambient temperature, and use the corrected temperature as the final set value to perform closed-loop control on the storage tank.

[0069] In an optional embodiment, the system performs defensive corrections for ambient humidity and then completes final control. Specifically, the system first collects the ambient relative humidity using sensors installed in the tank area. and ambient temperature Then, it is determined whether the relative humidity of the environment is greater than the preset high humidity threshold, such as greater than 80%. At this time, if the actual oil temperature in the storage tank is... Lower than the ambient temperature The hot, humid air drawn in through the breather valve easily condenses into water droplets on the cooler inner wall of the tank top and falls back onto the oil surface, potentially leading to microbial growth and raw material rancidity. Therefore, the system incorporates an environmental coupling correction mechanism to adjust the calculated target temperature... With ambient temperature Plus preset temperature difference The two anti-condensation critical values ​​are compared, and the larger value is taken as the final set value after correction. The final set value satisfies the following relationship:

[0070]

[0071] in, By setting a pre-defined temperature difference, such as 2 degrees Celsius, this correction strategy ensures that, regardless of the process heating requirements calculated based on rheological resistance and thermal life, the final tank control temperature in a high-humidity environment is always higher than the ambient temperature by a certain value. This effectively increases the temperature of the tank wall and the vapor space above the dew point, disrupting the condensation conditions of the humid air. When the measured oil temperature is lower than the final set value, the controller increases the heating output power to raise the oil temperature; when the measured oil temperature is higher than the final set value, the controller reduces or stops the heating output power and relies on the tank's natural heat dissipation to lower the oil temperature, thus achieving closed-loop control.

[0072] To more clearly illustrate the function and calculation method of the final temperature setpoint, a calculation example is provided:

[0073] Assuming the target temperature calculated in the preceding steps The temperature is 25 degrees Celsius, and the current environmental monitoring shows... 90%, ambient temperature The current oil temperature is 28 degrees Celsius. If the temperature is 25 degrees Celsius, the correction logic will be triggered:

[0074]

[0075] The system will force the oil to heat to 30 degrees Celsius, making the oil temperature higher than the ambient temperature to prevent condensation.

[0076] In this way, through environmental coupling correction, the system can actively raise the oil temperature to be slightly higher than the ambient temperature in a high humidity environment, forming a slightly positive pressure hot gas layer inside the tank and disrupting the condensation conditions. This effectively reduces the probability of the moisture drawn in by the breather valve condensing into water droplets on the inner wall of the tank top, thereby inhibiting the growth of microorganisms and ensuring the quality of raw materials.

[0077] Combination Figure 2 and Figure 3 The effects of the present invention will be further explained, such as... Figure 2 As shown, the dashed line representing the prior art remains at a fixed 50 degrees Celsius, without changing with time or operating conditions. The curve of the automatic temperature and humidity adjustment method for bio-oil storage tanks of the present invention shows an overall step-like downward trend, reflecting the logic of the target temperature upper limit decay caused by the cumulative thermal stress in the hyperbolic tangent function of the rheological resistance index. A convex peak appears in the middle of the curve, reflecting the automatic compensation heating logic triggered by the increase of the rheological resistance index in the rheological resistance index and the adaptive target temperature decision model.

[0078] like Figure 3 As shown, the curve representing accumulated thermal stress increases monotonically over time, while the other solid line represents the maximum allowable heating temperature, which is determined by the lifetime decay coefficient in the adaptive target temperature decision model. Figure 3This intuitively reflects how the maximum allowable heating temperature is forced to decrease as accumulated thermal stress increases, demonstrating a control strategy that trades lifespan for safety.

[0079] This invention also discloses an automatic temperature and humidity control system for a bio-oil storage tank, comprising a processor and a memory. The memory stores computer program instructions, which, when executed by the processor, implement an automatic temperature and humidity control method for a bio-oil storage tank according to the present invention.

[0080] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

[0081] In the description of this specification, "multiple" or "several" means at least two, such as two, three or more, unless otherwise expressly and specifically defined.

Claims

1. A method for automatic temperature and humidity regulation in a bio-oil storage tank, characterized in that, include: The operating data and current oil temperature of the storage tank conveying equipment are acquired. Based on this data, a rheological resistance index is constructed. This rheological resistance index characterizes the real-time viscosity of the oil. satisfy: This is the normalized proportionality coefficient; This refers to the real-time operating torque current of the delivery pump motor; The instantaneous flow rate within the pipe; To prevent division by zero constant; This is the current measured oil temperature; Reference temperature; An integral mechanism based on time is established to calculate the cumulative thermal stress of the oil over its entire life cycle based on the current oil temperature and a preset sampling period. The cumulative thermal stress is used to characterize the total thermal damage suffered by the oil during storage. Based on the rheological drag index and the accumulated thermal stress, the target temperature at the current moment is calculated using an adaptive target temperature decision model, which is used to balance the rheological drag index and the accumulated thermal stress. Target temperature satisfy: To maintain the basic insulation temperature to prevent the grease from solidifying; The maximum allowable temperature rise range; The hyperbolic tangent function value of the rheological drag index; The preset thermal life rating; This represents the total accumulated thermal stress at the current moment. The system collects ambient relative humidity and ambient temperature, performs environmental coupling correction on the target temperature based on the ambient relative humidity and ambient temperature, and uses the corrected temperature as the final set value to perform closed-loop control of the storage tank.

2. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, The accumulated thermal stress satisfies the following relationship: in, This represents the total cumulative thermal stress borne by the grease in the storage tank up to time t. This represents the total number of samples taken from the time the data was entered into the database until the current time. The temperature of the oil inside the tank recorded during the k-th sampling; This is the safe reference temperature for oil oxidation. This represents the sampling time interval.

3. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, The environmental coupling correction of the target temperature based on relative humidity and ambient temperature includes: Determine whether the relative humidity of the environment is greater than the high humidity threshold; If the relative humidity of the environment is greater than the high humidity threshold and the current measured oil temperature is lower than the ambient temperature, then the target temperature is compared with the sum of the ambient temperature and the preset temperature difference. The larger value is selected as the corrected target temperature so as to form a micro-positive pressure hot gas layer in the tank and destroy the condensation conditions. If the relative humidity of the environment is not greater than the high humidity threshold, or the current measured oil temperature is not less than the ambient temperature, then the target temperature is directly used as the final set value.

4. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, The closed-loop control of the storage tank includes: When the current oil temperature is lower than the final set value, the heating output power is increased; when the current oil temperature is higher than the final set value, the heating output is reduced or stopped and the oil is allowed to cool naturally in the storage tank, so that the oil temperature in the storage tank approaches the final set value.

5. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, The acquisition of operational data for the storage tank conveying equipment includes: The output torque and current of the motor can be read in real time through the inverter communication interface of the tank transfer pump. Instantaneous flow rate is read in real time by a mass flow meter or electromagnetic flow meter installed on the pipeline; The current measured oil temperature is read by a temperature transmitter installed at the bottom of the storage tank.

6. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, The normalization proportional coefficient is used to adjust the current-to-flow ratio of pumps with different power to a preset range.

7. The method for automatic temperature and humidity control of a bio-oil storage tank according to claim 1, characterized in that, In the adaptive target temperature decision model, the hyperbolic tangent function is used to perform a mathematical soft limiting effect by utilizing its saturation characteristics, preventing the calculated temperature from exceeding the safe range when the rheological drag index becomes infinite due to sensor failure.

8. An automatic temperature and humidity control system for a bio-oil storage tank, characterized in that, include: The processor and memory, wherein the memory stores computer program instructions that, when executed by the processor, implement the automatic temperature and humidity adjustment method for bio-oil storage tanks according to any one of claims 1-7.

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