Metal surface anti-corrosion and scale-inhibition synergistic protection process

Abstract

The invention relates to the technical field of physical prevention and removal of common dirt and surface cleaning, and discloses a metal surface corrosion prevention and scale inhibition collaborative protection process, which comprises the following steps of: acquiring a current feedback signal of an electric heating load in a power modulation period in real time, calculating an energy fluctuation value of power spectrum density in the signal, and calculating the power spectrum density of the electric heating load; the frequency compensation amount of the electric energy conversion circuit is determined according to the offset of the fluctuation value relative to the reference, and the electric energy conversion circuit is controlled to output a periodic pulse current with a preset rising edge slope to an electric heating load, so that an unsteady thermal gradient is generated on the surface of the load and a micro-turbulence shear force is excited; the potential hedging circuit is synchronously driven at the power rising section of the pulse current to apply voltage pulses with the same polarity as scale ions, a directive repulsion field is constructed, the load interface state is sensed through electrical parameter inversion, heterogeneous nucleation of solute ions is blocked through the synergistic effect of multi-field energy, and the service life of equipment is effectively prolonged.

Description

Technical Field

[0001] This invention belongs to the field of physical prevention and surface cleaning technology for general dirt, and particularly relates to a synergistic protection process for corrosion prevention and scale inhibition on metal surfaces. Background Technology

[0002] In current surface maintenance and scale prevention systems for industrial heating systems, ensuring the continuity and stability of the cleanliness of mass exchange at the heating interface is a fundamental principle of the power regulation circuit. Conventional solutions employ steady-state control logic, outputting constant power to the heating components to maintain the heat exchange efficiency at the interface. While this power supply mode ensures stable operation of the thermal system, it is difficult to actively suppress the adhesion of deposits to the surface when handling fluids containing impurities. Furthermore, when handling fluids with high mineralization, a physically relatively static thermal boundary layer is generated between the heating wall and the bulk fluid. Due to the lack of effective energy intervention, solute nuclei remain within this thermal boundary layer. The material rapidly reaches a supersaturated state and anchors to the surface of the heating tube. Simultaneously, the constant potential distribution causes electrochemical polarization in the heating tube substrate, inducing local pitting corrosion under high-temperature conditions. The industry commonly intervenes by adding chemical agents or increasing the fluid flow rate, but such methods introduce environmental pollution or increase the system's power consumption. In addition, introducing external mechanical vibration or ultrasonic components increases the hardware complexity of the power distribution system and increases the difficulty of system maintenance. As can be seen from the analysis, the existing solution is difficult to achieve the perception and protection of the interface deposition state by utilizing the power modulation characteristics of the electric heating circuit itself without changing the physical flow channel structure.

[0003] Existing structural improvements primarily focus on hardware layout, resulting in blind spots in the control logic. For example, the utility model patent with authorization announcement number CN207797725U discloses a DC injection-type furnace leakage alarm device that uses embedded probes in conjunction with a voltage separation circuit to determine the furnace leakage status. This type of monitoring emphasizes safety assurance, but its signal analysis dimension is singular, only identifying macroscopic anomalies in the circuit topology and failing to capture microscopic dynamic changes in interface thermal resistance. The injected static DC signal is easily interfered with by the system background charge, making it difficult to provide feedback guidance in the early stages of fouling and unable to link the power modulation circuit to generate multi-field energy counteraction. Existing technologies mainly suffer from the following shortcomings: 1. The power output mode is singular, unable to actively interfere with the physical state of the boundary layer during power transfer; 2. The interface potential distribution lacks dynamic adjustment, making it difficult to effectively suppress electrochemical polarization corrosion during heat exchange; 3. The power regulation process lacks sensing feedback for fouling risk, resulting in an inability to simultaneously achieve energy utilization efficiency and protective energy efficiency.

[0004] Therefore, how to induce micro-turbulence at the interface by modulating the power output curve and realize closed-loop adjustment of the protection strength by utilizing the electrical feedback characteristics has become the technical problem to be solved by this invention. Summary of the Invention

[0005] This invention provides a synergistic protection process for corrosion and scale inhibition on metal surfaces, comprising the following steps: Step S101: Real-time acquisition of the instantaneous current feedback signal output from the power conversion circuit to the electric heating load; Step S102: Discretely sample the instantaneous current feedback signal to calculate the broadband energy fluctuation value of its power spectral density, and calculate the output frequency compensation amount of the power conversion circuit in real time based on the degree of deviation of the broadband energy fluctuation value relative to the preset reference, so as to form a closed-loop power supply modulation rule. Step S103: Drive the power conversion circuit to output a periodic pulse current with a preset rise slope to the electric heating load according to the power supply modulation rule, and induce an unsteady thermal gradient on the surface of the electric heating load to excite a spontaneous buoyancy plume with microscopic shear force. Step S104: Monitor the phase state of the periodic pulse current, and synchronously drive the potential counter-current circuit to apply a voltage pulse to the electric heating load within the time interval corresponding to the power rise segment of the periodic pulse current, so as to build a directional repulsive field for scale precursor ions on the surface of the electric heating load. Through the temporal overlap of physical thermal expansion perturbation and Coulomb repulsion, the heterogeneous nucleation of scale precursor ions on the surface of the electric heating load is suppressed.

[0006] Preferably, in step S103, the preset rising edge slope is limited to enable the electric heating load to complete the transition of output power from initial power to peak power within 5ms to 15ms; the modulation frequency of the periodic pulse current is set to 10Hz to 500Hz; in step S104, the start time of the voltage pulse lags behind the starting point of the rising edge of the periodic pulse current by 10μs to 50μs.

[0007] Preferably, in step S101, the instantaneous current feedback signal is obtained by: applying a probe narrow pulse to the electric heating load during the power off gap of the periodic pulse current, collecting the feedback voltage sequence generated by the electric heating load in response to the probe narrow pulse, and calculating the equivalent damping parameter characterizing the thermal resistance state of the electric heating load interface.

[0008] Preferably, in step S102, the output frequency of the periodic pulse current is... Dynamic correction should be performed according to the following rules: ,in, The corrected output frequency; β is the preset base switching frequency; β is the preset frequency adjustment operator; ΔE is the real-time change in broadband energy fluctuation value. This is the preset standard spectral energy reference value.

[0009] Preferably, in step S104, the peak voltage of the voltage pulse is nonlinearly compensated according to the fluid flow rate of the environment in which the electric heating load is located; when the fluid flow rate is detected to decrease, the amplitude of the voltage pulse is increased to enhance the strength of the directional repulsive field, thereby compensating for the risk of ion deposition caused by the increase in diffusion resistance in the dead zone of the flow channel.

[0010] Preferably, the pulse width of the voltage pulse is limited to 2% to 8% of the periodic pulse current period, and the potential polarity of the voltage pulse is set to be the same as the charge polarity of the scale ions in the fluid to be treated inside the electric heating load.

[0011] Preferably, the method further includes step S105: during the standby period when the electric heating load is in a non-heating state, the power conversion circuit is switched to enter the polarization mode to output a constant current lower than the hydrogen evolution potential to the electric heating load, and during the maintenance period of the constant current, the potential counteracting circuit outputs a low-frequency maintenance potential to construct a dynamic electrochemical passivation environment on the surface of the electric heating load.

[0012] Preferably, the electric heating load includes multiple heating branches configured in parallel; in step S103, by adjusting the time delay phase of the pulse output between the multiple heating branches, periodic pressure pulsation is induced inside the heat exchange container, and the pressure pulsation is used to enhance the peeling efficiency of the spontaneous buoyancy plume on the surface of the electric heating load.

[0013] Preferably, in step S102, the specific process of extracting the broadband energy fluctuation value includes: performing a fast Fourier transform on the instantaneous current feedback signal to obtain its characteristic power spectrum in the frequency band of 1kHz to 10kHz, calculating the energy integral value of the characteristic power spectrum, and determining the change of the energy integral value over time as a characteristic parameter reflecting the thickness of the interface scale layer.

[0014] Preferably, the method further includes step S106: calculating the slope of the broadband energy fluctuation value in real time, and when the slope exceeds the preset safety threshold for three consecutive detection cycles, forcibly increasing the instantaneous duty cycle of the periodic pulse current to more than 80% by the control terminal, so as to generate alternating thermal stress on the surface of the electrically heated load that is sufficient to destroy the hard scale structure.

[0015] Compared with existing technologies, the synergistic protection process for corrosion prevention and scale inhibition on metal surfaces of this invention has the following advantages: 1. In the synergistic protection of scale and corrosion on metal surfaces, an asymmetric periodic power output characteristic consisting of a rapid power increase segment and a slow power decrease segment is adopted. The electrothermal inertia of the heating component itself directly drives the fluid to generate micro-dynamic instability at the heating interface, thereby achieving dynamic physical peeling of the interface deposits. The rapid power increase segment induces instantaneous thermal expansion of the laminar fluid adjacent to the heating surface, and under the action of gravity, it excites micron-level spontaneous buoyancy plumes. The continuous micro-shear force formed at the interface destroys the anchoring conditions of solute crystal nuclei. This endogenous shear force generated by the modulation of the energy input curve transforms the heating interface from a passive defense state under steady-state heat transfer to an active immune state with the property of repelling deposits, effectively eliminating the risk of crystallization caused by solute supersaturation in the thermal boundary layer.

[0016] 2. By monitoring the instantaneous current signal of the heating component during the power modulation cycle, the thermoelectric feedback component reflecting the interface thermal resistance characteristics is extracted. This enables the heating component to perform interface state sensing functions while performing heating tasks. The thermoelectric feedback component can sensitively capture the change in thermal diffusion rate caused by the accumulation of micro-scale deposits at the interface and map it into an interface damping characteristic parameter that characterizes the degree of solute accumulation. This drives the controller to perform closed-loop correction on the peak value or frequency of subsequent power pulses, ensuring that the shear strength of micro-turbulence always matches the real-time scale inhibition risk, maintaining the stability of protection efficiency under variable flow conditions, and avoiding material fatigue loss caused by excessive energy pulses.

[0017] 3. The electrochemical potential energy counteraction step and the phase synchronization lock of the thermal pulse power waveform are executed. By utilizing the precise overlap of the mechanical repulsion force generated by physical expansion and the electrostatic repulsion force of the same polarity within the microsecond time sequence, a vector resultant force window for scale precursor ions is constructed. During the repulsion period corresponding to the rapid power increase segment, a transient potential of the same polarity as the scale ions is applied simultaneously to push the charged ions in the pre-adsorption state away from the heating interface and guide them to the main flow region. This reduces the chemical affinity of the heating surface to the deposits at the molecular level, solves the boundary effect of single physical flushing in extreme high-salt environments, and keeps the interface in a clean state with near-zero adsorption for a long time. Attached Figure Description

[0018] Figure 1 This is a process flow diagram of the synergistic protection process for metal surface corrosion prevention and scale inhibition according to the present invention; Figure 2 This is a schematic diagram of the system composition and multi-field energy coupling control principle of the collaborative protection process of this invention. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0020] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0021] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood in conjunction with the specific circumstances.

[0022] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0023] A synergistic protection process for corrosion and scale inhibition on metal surfaces includes the following steps: Step S101: Real-time acquisition of the instantaneous current feedback signal output from the power conversion circuit to the electric heating load; Step S102: Discretely sample the instantaneous current feedback signal to calculate the broadband energy fluctuation value of its power spectral density, and calculate the output frequency compensation amount of the power conversion circuit in real time based on the degree of deviation of the broadband energy fluctuation value relative to the preset reference, so as to form a closed-loop power supply modulation rule. Step S103: Drive the power conversion circuit to output a periodic pulse current with a preset rise slope to the electric heating load according to the power supply modulation rule, and induce an unsteady thermal gradient on the surface of the electric heating load to excite a spontaneous buoyancy plume with microscopic shear force. Step S104: Monitor the phase state of the periodic pulse current, and synchronously drive the potential counter-current circuit to apply a voltage pulse to the electric heating load within the time interval corresponding to the power rise segment of the periodic pulse current, so as to build a directional repulsive field for scale precursor ions on the surface of the electric heating load. Through the temporal overlap of physical thermal expansion perturbation and Coulomb repulsion, the heterogeneous nucleation of scale precursor ions on the surface of the electric heating load is suppressed.

[0024] Preferably, in step S103, the preset rising edge slope is limited to enable the electric heating load to complete the transition of output power from initial power to peak power within 5ms to 15ms; the modulation frequency of the periodic pulse current is set to 10Hz to 500Hz; in step S104, the start time of the voltage pulse lags behind the starting point of the rising edge of the periodic pulse current by 10μs to 50μs.

[0025] Preferably, in step S101, the instantaneous current feedback signal is obtained by: applying a probe narrow pulse to the electric heating load during the power off gap of the periodic pulse current, collecting the feedback voltage sequence generated by the electric heating load in response to the probe narrow pulse, and calculating the equivalent damping parameter characterizing the thermal resistance state of the electric heating load interface.

[0026] Preferably, in step S102, the output frequency of the periodic pulse current is... Dynamic correction should be performed according to the following rules: ,in, The corrected output frequency; β is the preset base switching frequency; β is the preset frequency adjustment operator; ΔE is the real-time change in broadband energy fluctuation value. This is the preset standard spectral energy reference value.

[0027] Preferably, in step S104, the peak voltage of the voltage pulse is nonlinearly compensated according to the fluid flow rate of the environment in which the electric heating load is located; when the fluid flow rate is detected to decrease, the amplitude of the voltage pulse is increased to enhance the strength of the directional repulsive field, thereby compensating for the risk of ion deposition caused by the increase in diffusion resistance in the dead zone of the flow channel.

[0028] Preferably, the pulse width of the voltage pulse is limited to 2% to 8% of the periodic pulse current period, and the potential polarity of the voltage pulse is set to be the same as the charge polarity of the scale ions in the fluid to be treated inside the electric heating load.

[0029] Preferably, the method further includes step S105: during the standby period when the electric heating load is in a non-heating state, the power conversion circuit is switched to enter the polarization mode to output a constant current lower than the hydrogen evolution potential to the electric heating load, and during the maintenance period of the constant current, the potential counteracting circuit outputs a low-frequency maintenance potential to construct a dynamic electrochemical passivation environment on the surface of the electric heating load.

[0030] Preferably, the electric heating load includes multiple heating branches configured in parallel; in step S103, by adjusting the time delay phase of the pulse output between the multiple heating branches, periodic pressure pulsation is induced inside the heat exchange container, and the pressure pulsation is used to enhance the peeling efficiency of the spontaneous buoyancy plume on the surface of the electric heating load.

[0031] Preferably, in step S102, the specific process of extracting the broadband energy fluctuation value includes: performing a fast Fourier transform on the instantaneous current feedback signal to obtain its characteristic power spectrum in the frequency band of 1kHz to 10kHz, calculating the energy integral value of the characteristic power spectrum, and determining the change of the energy integral value over time as a characteristic parameter reflecting the thickness of the interface scale layer.

[0032] Preferably, the method further includes step S106: calculating the slope of the broadband energy fluctuation value in real time, and when the slope exceeds the preset safety threshold for three consecutive detection cycles, forcibly increasing the instantaneous duty cycle of the periodic pulse current to more than 80% by the control terminal, so as to generate alternating thermal stress on the surface of the electrically heated load that is sufficient to destroy the hard scale structure.

[0033] Example 1: In a large-scale circulating cooling water treatment process, the electrically heated load is surrounded by a fluid medium with high salinity and fluctuating flow rate. During the steady-state heat transfer process at the heating interface, a relatively static thermal boundary layer is generated near the wall. Scale precursors such as calcium and magnesium ions within this layer rapidly reach supersaturation and tend to nucleate heterogeneously on the heating surface. Simultaneously, the constant potential distribution on the heating surface induces electrochemical polarization in the base metal, leading to pitting corrosion damage under high temperature and high salinity conditions. The protection process acquires the instantaneous current feedback signal output from the power conversion circuit to the electrically heated load in real time. This signal is sampled, and its broadband energy fluctuation value of the power spectral density is calculated to reflect the change in thermal resistance at the interface caused by the accumulation of micro-deposit. The real-time change ΔE of the broadband energy fluctuation value is compared with a preset standard spectral energy reference value. Perform a comparison and calculate the output frequency compensation amount according to the following formula: ;in, The corrected output frequency, β is the preset base switching frequency, β is the preset frequency adjustment operator, and ΔE is the real-time change in broadband energy fluctuation value. The preset standard spectrum energy reference value is used to form a closed-loop perception of the risk of interface crystallization. The controller drives the power conversion circuit to output a periodic pulse current with a preset rising edge slope to the electric heating load according to the output frequency compensation amount. The preset rising edge slope enables the electric heating load to complete the transition of output power from the initial power to the peak power within 10ms. This rapid electrothermal power input uses the electrothermal inertia of the heating component itself to induce instantaneous thermal expansion of the heating surface, thereby exciting the generation of micron-level spontaneous buoyancy plumes under the action of gravity. The spontaneous buoyancy plumes form microscopic shear forces at the interface, which physically destroy the anchoring conditions of scale precursors on the heating surface.

[0034] The system monitors the phase state of the periodic pulse current and synchronously drives the potential counter-current circuit to apply a voltage pulse with the same polarity as the scale ions to the electrically heated load within the time interval corresponding to the power rise of the periodic pulse current. The start time of the voltage pulse is set to lag the start of the rise edge of the periodic pulse current by 30μs. By utilizing the precise overlap of the mechanical repulsive force generated by thermal expansion and the Coulomb repulsive force of the same polarity within the microsecond time interval, a directional repulsive field for scale precursor ions is constructed on the heated surface to suppress the heterogeneous nucleation of scale precursor ions on the surface of the electrically heated load. During the power off gap of the periodic pulse current, a narrow detection pulse is applied to the electrically heated load and the feedback voltage sequence is collected to calculate the equivalent damping parameter characterizing the thermal resistance state of the interface. When the system detects that the fluid flow rate decreases and the diffusion resistance increases, the system increases the amplitude of the voltage pulse to strengthen the intensity of the directional repulsive field. By utilizing the radial backflow inertia generated by the fluid contraction during the slow cooling section, the ions that have been shaken away from the interface are further carried away from the thermal boundary layer. The metal surface remains clean throughout the continuous operation test.

[0035] Example 2: In a test simulating high-mineralization industrial circulating water, the performance of the synergistic protection process for metal surface corrosion prevention and scale inhibition was verified. The test platform consisted of a multi-channel electric heating test circuit, an instantaneous current sampling unit, and an interface temperature field monitoring system. The sampling frequency of the instantaneous current sampling unit was set to 50kHz, and the quantization resolution was 16bit. The test medium was a water sample with a total hardness of 850mg / L, a calcium ion concentration of 480.5mg / L, and a magnesium ion concentration of 125.6mg / L. Gaussian white noise with a signal-to-noise ratio of 25dB was superimposed at the signal input. A control group was established, with a constant electric power of 150kW / m² applied. After 120 hours of operation, the average temperature of the heated surface increased from the initial 85.2℃ to 112.6℃, and the average scale thickness was measured to be 1.42mm. To verify the synergistic effect of the technical features, a first comparative sample group was established, using only periodic pulse current modulation with a rise time of 10ms, without applying a voltage pulse. The broadband energy fluctuation value ΔE was compared with the standard spectrum energy reference value. The offset ranged from 12.5% ​​to 15.8%, and the average thickness of the scale layer after 120 hours of operation was 0.65 mm, reflecting that a single physical disturbance could not completely block the deposition process. In the sample group of this invention, a complete synergistic protection process was adopted, and the voltage pulse start time was set to lag the rise edge of the periodic pulse current by 30 μs. The broadband energy fluctuation value ΔE was observed to converge to below 4.2%, and the risk of interface crystallization was maintained at a low level.

[0036] The system calculates the output frequency compensation amount according to the following formula: ;in, The corrected output frequency, β is the preset base switching frequency, β is the frequency adjustment operator, and ΔE is the real-time change in broadband energy fluctuation value. The preset standard spectral energy reference value; the obtained The frequency was set to 55.4 Hz, thus filtering out frequency jitter caused by signal noise. A second control group was established, with the rise time extended to 25 ms. The test results showed that the average scale thickness increased to 1.12 mm. The reason for this trend was that the power rise slope decreased, which made it impossible to generate a spontaneous buoyancy plume. When the voltage pulse lag time increased to 100 μs, the Coulomb repulsion and thermal expansion physical disturbance were misaligned in the time domain, and the rate of increase in interface thermal resistance accelerated. The microscopic characterization of the interface after 120 h of operation showed that there was no calcium carbonate crystal accumulation and no pitting on the heated load surface of the sample group of the present invention, which confirmed that the synergistic effect of multiple fields effectively blocked the risk of scale inhibition and corrosion.

[0037] Example 3: In the initial calibration phase of industrial heat exchange system deployment or electric heating load replacement, the heating interface is in a clean state and the fluid medium is static. The system executes an adaptive parameter generation process to establish the logical starting point of the protection process. The power conversion circuit outputs a small-signal excitation current with an amplitude of 10% of the rated operating current. The instantaneous current sampling unit collects the instantaneous current feedback signal at a sampling frequency of 50kHz for 50 consecutive cycles. The controller performs a fast Fourier transform on the collected signal sequence and calculates the power spectral density. By integrating the power spectral components in the frequency domain range of 10kHz to 25kHz, a standard spectral energy reference value is generated. ;in, Using the reference energy value, the system applies a narrow probe pulse with a pulse width of 5 μs to the electrically heated load during the power off interval, and calculates the initial characteristic entropy based on the feedback voltage sequence. .

[0038] To determine the dynamic threshold for micron-sized scale nuclei, crystallization inducers at concentrations ranging from 100 mg / L to 500 mg / L were added to the fluid medium in a gradient manner. The feedback voltage sequence was monitored, and the real-time characteristic entropy H was calculated. The formula for calculating the characteristic entropy H is as follows: Where H is the feature entropy; n is the number of samples, which takes the value 512; The probability density of the feedback voltage amplitude distribution is used; when the formation of a primary crystal nucleus with a thickness of 8.5 μm is detected on the heated surface, the characteristic entropy H at this time is recorded. The difference and determine the critical trigger threshold ;in, The critical trigger threshold; the obtained and The data is written to the controller's internal non-volatile memory; after parameter calibration, the system enters a protection loop, and the controller acquires the broadband energy fluctuation value ΔE in real time and compares it with the stored data. For comparison, when the fluid conductivity fluctuates within the range of 2.5 mS / cm to 3.0 mS / cm, the system uses the formula... Dynamically correct output frequency ;in, The corrected output frequency, The base switching frequency is 50Hz; β is the frequency adjustment operator with a value of 0.8; the calculated... The command drives the power conversion circuit to adjust the output frequency of the periodic pulse current. Under the condition of a 20% change in fluid conductivity, the system's error in identifying deposition risk remains within 2.8%.

[0039] Example 4: In the commissioning scenario of deploying a new system or replacing different batches of electric heating loads, the current sampling signal may experience zero-point offset due to differences in manufacturing tolerances and the initial background conductivity of the fluid. The system performs zero-point calibration, and the controller drives the power conversion circuit to output a preset signal with an amplitude of 5% of the rated operating current at a frequency of 100Hz within 5 seconds. The instantaneous current sampling unit collects the current sequence and calculates the initial power spectral density distribution, smooths the power spectral components of 100 consecutive sampling periods, extracts the energy integral value in the frequency band from 10kHz to 25kHz, and assigns it to the standard spectral energy reference value. Establish an energy baseline point for the heating interface under clean conditions, while simultaneously monitoring the feedback voltage sequence and calculating the initial characteristic entropy. The critical trigger threshold is determined based on the background conductivity of the fluid under static conditions. .

[0040] When the protection system operates in a fluid medium containing dissolved oxygen and chloride ions and detects uneven surface potential distribution of the heated load, online calibration is performed using the power off-state gap of a periodic pulse current. Physical parameters of the interface are acquired by applying a narrow probe pulse with a 1% duty cycle to the electrically heated load. The controller updates the value of the characteristic entropy H based on the real-time acquired feedback voltage sequence; where H is the real-time characteristic entropy; when the change in characteristic entropy... Deviation from critical trigger threshold When; where ΔH is the real-time change of characteristic entropy; the controller drives the potential counteracting circuit to adjust the pulse width of the voltage pulse, and positions the start time of the voltage pulse at 30μs after the start of the rising edge of the periodic pulse current. The overlap of Coulomb repulsion and microscopic shear force generated by thermal expansion in the boundary layer inhibits the germination of pitting nuclei, so that the potential of the heated load surface is maintained within the preset electrochemical window.

[0041] Example 5: In the installation scenario of a multi-tube bundle heat exchanger, the system performs parameter calibration for the spatial orientation of the heat exchange interface, determines the angle α between the axis of the electric heating load and the vertical direction, and selects the value of the angle α within the range of 30° to 60°. This is used to adjust the tangential component of the spontaneous buoyancy plume on the surface of the electric heating load, and the stripping energy is calculated using the following formula. Verify the intensity of the physical disturbance: ;in, γ is the stripping energy value, γ is the interface coupling coefficient; ΔT is the instantaneous temperature rise of the interface corresponding to the rising segment of the periodic pulse current, and α is the angle between the axis of the electric heating load and the vertical direction; the calculation results are used to determine whether the generated microscopic shear force is sufficient to strip the scale precursor crystal nuclei under the current conductivity environment.

[0042] The system adjusts the radial transport characteristics of the fluid medium by controlling the shape of the power drop-off phase during the heating protection cycle, and determines the slow cooling slope σ of the periodic pulse current before power shutdown. The formula for calculating the slow cooling slope σ is as follows: Where σ is the slope of the slow cooling process, Peak power, For initial power, To control the cooling time, σ is controlled within the range of 1.5W / ms to 3.5W / ms. This induces a volumetric displacement of the fluid towards the axis of the electrically heated load due to the temperature drop. When the equivalent damping parameter of the narrow pulse feedback is nonlinearly deflected, the power cut-off gap is extended. The inertial flow field generated by the fluid contraction carries the ions that have been shaken off the interface away from the thermal boundary layer. The fouling rate on the surface of the electrically heated load is always lower than the corrosion rate of the substrate material.

[0043] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A synergistic protective process for corrosion prevention and scale inhibition on metal surfaces, characterized in that, Includes the following steps: Step S101: Real-time acquisition of the instantaneous current feedback signal output from the power conversion circuit to the electric heating load; Step S102: Discretely sample the instantaneous current feedback signal to calculate the broadband energy fluctuation value of its power spectral density, and calculate the output frequency compensation amount of the power conversion circuit in real time based on the degree of deviation of the broadband energy fluctuation value relative to the preset reference, so as to form a closed-loop power supply modulation rule. Step S103: Drive the power conversion circuit to output a periodic pulse current with a preset rise slope to the electric heating load according to the power supply modulation rule, and induce an unsteady thermal gradient on the surface of the electric heating load to excite a spontaneous buoyancy plume with microscopic shear force. Step S104: Monitor the phase state of the periodic pulse current, and synchronously drive the potential counter-current circuit to apply a voltage pulse to the electric heating load within the time interval corresponding to the power rise segment of the periodic pulse current, so as to build a directional repulsive field for scale precursor ions on the surface of the electric heating load. Through the temporal overlap of physical thermal expansion perturbation and Coulomb repulsion, the heterogeneous nucleation of scale precursor ions on the surface of the electric heating load is suppressed.

2. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, In step S103, the preset rising edge slope is limited to enable the electric heating load to complete the transition of output power from initial power to peak power within 5ms to 15ms; the modulation frequency of the periodic pulse current is set to 10Hz to 500Hz; in step S104, the start time of the voltage pulse lags behind the starting point of the rising edge of the periodic pulse current by 10μs to 50μs.

3. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, In step S101, the instantaneous current feedback signal is obtained by applying a narrow detection pulse to the electric heating load during the power off gap of the periodic pulse current, collecting the feedback voltage sequence generated by the electric heating load in response to the narrow detection pulse, and calculating the equivalent damping parameter characterizing the thermal resistance state of the electric heating load interface.

4. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, In step S102, the output frequency of the periodic pulse current Dynamic correction should be performed according to the following rules: ,in, The corrected output frequency; β is the preset base switching frequency; β is the preset frequency adjustment operator; ΔE is the real-time change in broadband energy fluctuation value. This is the preset standard spectral energy reference value.

5. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, In step S104, the peak voltage of the voltage pulse is nonlinearly compensated according to the fluid flow rate of the environment in which the electric heating load is located; when the fluid flow rate decreases, the amplitude of the voltage pulse is increased to enhance the strength of the directional repulsive field, thereby compensating for the risk of ion deposition caused by the increased diffusion resistance in the dead zone of the flow channel.

6. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, The pulse width of the voltage pulse is limited to 2% to 8% of the periodic pulse current period, and the potential polarity of the voltage pulse is set to be the same as the charge polarity of the scale ions in the fluid to be treated inside the electrically heated load.

7. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, It also includes step S105: during the standby period when the electric heating load is in a non-heating state, the power conversion circuit is switched to enter the polarization mode, and a constant current lower than the hydrogen evolution potential is output to the electric heating load. During the maintenance period of the constant current, a low-frequency maintenance potential is output by the potential counteracting circuit to build a dynamic electrochemical passivation environment on the surface of the electric heating load.

8. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, The electric heating load includes multiple heating branches configured in parallel; in step S103, by adjusting the time delay phase of the pulse output between the multiple heating branches, periodic pressure pulsation is induced inside the heat exchange container, and the pressure pulsation is used to enhance the peeling efficiency of the spontaneous buoyancy plume on the surface of the electric heating load.

9. The synergistic protection process for corrosion prevention and scale inhibition on metal surfaces according to claim 1, characterized in that, In step S102, the specific process of extracting broadband energy fluctuation values ​​includes: performing a fast Fourier transform on the instantaneous current feedback signal to obtain its characteristic power spectrum in the 1kHz to 10kHz frequency band, calculating the energy integral value of the characteristic power spectrum, and determining the change of the energy integral value over time as a characteristic parameter reflecting the thickness of the interface scale layer.

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