Solar spectrum frequency division combined heat and power generation system and operation method

Abstract

The invention discloses a solar spectrum frequency division combined heat and power generation system and an operation method, and relates to the technical field of renewable energy sources, and the method comprises the following steps: S001, building a coupling analysis baseline among irradiation parameters, heat distribution and optical characteristics, collecting the real-time temperature data and light beam wavefront information of a spectrum frequency divider under the condition of sun illumination, and calculating the real-time temperature data and light beam wavefront information of the spectrum frequency divider; and generating an estimated atlas of refractive index gradient distribution based on a thermally induced refractive index change rule. Through heat, light and force coupling control, accurate prediction, real-time identification and dynamic correction of the thermal lens effect are achieved, a closed-loop feedback mechanism is established, stable alignment of photoelectric and photo-thermal paths is guaranteed, the system energy efficiency and operation reliability are effectively improved, and the problems of deviation, energy efficiency reduction and part damage caused by a thermal lens in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of renewable energy, and in particular to a solar spectrum frequency division cogeneration system and an operation method thereof. Background Art

[0002] Solar spectrum frequency-splitting combined heat and power (CHP) operation refers to a method of operation in which, during the solar energy utilization process, the spectrum of sunlight in different wavelength ranges is separated, the high-energy short-wave portion (primarily visible light and some near-infrared) is used for photovoltaic power generation, and the low-energy long-wave portion (primarily mid- and far-infrared) is used for photothermal conversion to drive thermal energy devices, thereby achieving the simultaneous output and efficient coordinated utilization of electrical and thermal energy. This method achieves directional diversion of solar radiation through spectral frequency-splitting devices (such as multi-layer film filters, prism structures, or selective absorption coatings), and dynamically adjusts the ratio of photovoltaic and photothermal output according to real-time irradiation conditions and system load status. While improving the overall energy conversion efficiency, it also reduces heat loss and energy waste in a single energy path. It is widely used in scenarios such as solar buildings, microgrid energy stations, and off-grid independent energy systems, and is one of the key operating strategies for achieving multi-energy synergy and intelligent energy management.

[0003] The existing technology has the following deficiencies: In existing technologies, spectrum splitting devices are often used in solar cogeneration applications to direct solar radiation energy from different wavelengths to photovoltaic power generation units and photothermal conversion units, thereby improving overall energy utilization efficiency. However, under long-term, high-energy focusing conditions, the splitter structures used in existing technologies generally fail to fully consider the thermal stability of the internal materials under high-intensity irradiation, which can easily form temperature gradients within the device, leading to non-uniform changes in the local refractive index of the material and an optical thermal lensing effect. When thermal lensing occurs, the originally collimated or directed light beam will experience spatial focal drift, causing light from different wavelengths to deviate from the intended receiving area. This can result in the photovoltaic module not receiving sufficient visible light radiation, or the thermal collector being unable to effectively absorb infrared energy. In severe cases, this can cause a sharp drop in the output efficiency of the light energy path. Furthermore, beam deviation can disrupt the dynamic load balance between the photovoltaic and photothermal paths, leading to energy distribution disruption, asynchronous electrothermal output, overload of energy storage equipment, or operational scheduling failure, further inducing safety risks such as unstable operation, delayed response, and even thermal damage to key components.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Summary of the Invention

[0005] The object of the present invention is to provide a solar spectrum frequency division cogeneration system and an operation method thereof to solve the problems in the above-mentioned background technology.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a solar spectrum frequency division cogeneration operation method, comprising the following steps: S001: Establish a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. Collect real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions. Generate an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. S002: Based on the estimated atlas of the refractive index gradient distribution, identify the thermal lens sensitivity factor that causes the spot offset, extract the corresponding spot offset threshold, film stress threshold, and focus tolerance, and use this to establish physical constraints for determining the beam offset state; S003, constructing a focus shift discriminator based on physical constraints, inverting the real-time focus coordinates based on the beam wavefront information, calculating the corresponding energy flux density, and classifying the degree of spot shift into a grade label; S004, dynamically adjusting the spectral splitting path according to the spot offset level label, achieving spectral reconstruction by adjusting the incident angle and bandpass width, and simultaneously driving the flexible microactuator to perform an optical axis correction operation so that the reconstructed light beam is stably projected to the predetermined energy receiving area; S005: Feedback the operating status after optical axis correction and spectral splitting adjustment to the thermal management system. Based on the heat distribution in the energy receiving area, liquid cooling flow pulses are applied and the phase change heat conduction channel is switched. At the same time, the absorptivity of the crossover surface coating is adjusted to achieve a coordinated closed-loop operation of optical path adjustment and thermal management control. S006, based on the energy output data of the collaborative closed-loop operation, evaluate the overall operation effect of the system, adaptively correct the threshold of the thermal lens sensitivity factor according to the evaluation results, and update the parameters of the focus shift discriminator to achieve dynamic optimization of the thermal lens suppression strategy.

[0007] Preferably, step S001 includes: A simulated sunlight irradiation environment with a wavelength output capability of 300nm to 2500nm was constructed, and the output beam was focused using a combination of a quartz collimating lens and a parabolic reflector, projecting the beam onto the surface of a multilayer film spectrum divider sample; Under high-energy irradiation conditions, thermistors and infrared thermometers were used to collect real-time temperature data from the center, edge, and film interlayer of the spectrum divider surface, and the data were transmitted to the host platform at a frequency of 1 Hz. Synchronously collect the wavefront information formed by the light beam after passing through the spectrum divider, use the microlens array wavefront detection device to record the phase distortion of the outgoing light, and form a time-synchronized data pair with the corresponding temperature data; According to the thermally induced refractive index variation coefficient of each film material of the frequency divider, the refractive index variation value at each spatial position is calculated in combination with the temperature measurement data, and the three-dimensional refractive index gradient distribution map is reconstructed. The gradient greater than 0.05 is marked by color mapping. The area is a high-risk area for thermal lensing, so as to form an optical prediction map for subsequent offset judgment.

[0008] Preferably, step S002 includes: Based on the obtained refractive index gradient distribution map, the refractive index change value greater than Each millimeter of heat-sensitive area is regarded as a high-risk area, and the temperature sampling data of the corresponding area is extracted for heat accumulation feature analysis; In the high-risk area mentioned above, the equivalent internal stress change caused by temperature rise was measured in combination with the film structure of the spectrum divider, and the film stress threshold correlated with the spot offset height was extracted. The film stress threshold was set to 65MPa. By measuring the energy distribution of the light spot at different offset positions, it was determined that an offset exceeding 0.6mm would result in a significant decrease in energy reception. Based on this, the focus tolerance was set to within 0.6mm. Based on the spot offset threshold, film stress threshold and focusing tolerance, physical constraints are established to determine the beam offset state. When any position meets the above three physical conditions at the same time, it is determined that focus drift induced by thermal lensing occurs at that position.

[0009] Preferably, step S003 includes: Based on the established physical constraints on spot deviation, a microlens array wavefront sensor was placed on the main axis of the spectral divider's outgoing direction. The sensor collected a two-dimensional wavefront phase diagram of the outgoing beam under sunlight and monitored the optical axis deviation at a frequency of 20 frames per second. When the principal optical axis represented by the wavefront data deviates by more than 0.2 mm in the X or Y direction, the coordinates of the focus in the X, Y, and Z directions in three-dimensional space are calculated based on the relationship between the phase contour density in the wavefront image and the optical path tracing, and the spatial offset distance of the focus relative to the reference position is obtained; A receiving device composed of a high-stability liquid crystal temperature-sensitive film is set at the focal position, and a two-dimensional thermal map of the focal hot zone is measured with an infrared thermal imager. The focal energy flux density distribution is obtained through grayscale inversion, and the degree of focal energy concentration is evaluated. The focal spatial offset distance and the concentration of energy flux density are used as joint criteria. According to the extracted spot offset threshold, film stress threshold and focusing tolerance, the current spot offset state is divided into five levels, marked as level one to level five, which serve as the basis for the subsequent dynamic adjustment of the spectral path and correction of the incident angle.

[0010] Preferably, step S004 includes: Based on the determined spot offset level label, determine whether to trigger the spectral path adjustment operation. If the offset level is level 1, no adjustment is performed. If it is level 2, the incident angle fine-tuning operation is performed. If it is level 3 or above, the incident angle adjustment, bandpass width adjustment and optical axis correction operations are performed simultaneously. The tiltable reflector assembly driven by piezoelectric ceramics is used to adjust the inclination of the reflector in the X and Y directions, controlling the reflection angle within the range of ±3°, changing the main incident angle of the light beam entering the spectrum splitter, and realigning the split light beam to the target energy receiving area. The thickness of the interference filter layer is adjusted using a piezoelectric micro-drive, and the bandpass center wavelength is adjusted within the range of ±50nm, controlling the bandwidth to be compressed to 25nm or 20nm, thereby improving the concentration of spectral energy and reception efficiency. The piezoelectric ceramic drive unit on the flexible hinge platform is used to perform micro-displacement corrections on the optical axis in the X-axis and Y-axis directions, so that the light beam remains perpendicular to the target receiving surface. Ultimately, the landing point offset of the corrected light beam is controlled within ±0.2mm, ensuring stable energy transmission to the photovoltaic or solar thermal unit.

[0011] Preferably, step S005 includes: After completing the optical axis correction and spectral splitting path adjustment operations, based on the heat redistribution on the receiving surface, a thermocouple array and infrared thermal imaging equipment arranged on the back of the photovoltaic module and behind the heat absorption surface are used to collect a two-dimensional temperature distribution map of the hot surface, and determine whether there is a heat concentration state with a central temperature higher than 50°C and a peripheral temperature lower than 30°C; When the heat concentration state is determined to be established, the liquid cooling plate structure is controlled to apply an instantaneous strong cooling flow pulse, instantly increasing the flow rate from 300mL / min to 450mL / min. The pulse duration is 5 seconds to quickly diffuse the local heat and reduce the temperature rise in the central overheating area. After the liquid cooling pulse operation is completed, the heat conduction paths of the paraffin and indium tin phase change heat conduction structures are switched according to the temperature differences in different areas of the hot surface. When the hot surface temperature is between 45°C and 55°C, the paraffin heat conduction path is activated, and when the temperature is close to 80°C, the indium tin heat conduction path is activated, achieving balanced conduction and release of deep heat. Based on the focus shift level and thermal distribution characteristics, the absorption performance of the multi-layer absorption film composed of chromium oxide black and silicon nitride deposited on the surface of the spectral divider is adjusted, and the surface temperature is fine-tuned to within ±5°C through a graphite heater, thereby achieving an absorption rate increase of no more than 2% in the mid- and far-infrared bands, thereby enhancing energy absorption stability and synergistically alleviating photothermal fluctuations under high shift levels.

[0012] Preferably, step S006 includes: After completing the optical axis correction and thermal management closed-loop operation, collect the DC voltage, current, output power and power fluctuation amplitude of the photovoltaic array, as well as the inlet temperature, outlet temperature, volume flow rate and heat transfer efficiency data of the heat medium at the heat absorption end during the current complete operation cycle, and determine whether there is a total energy drop of more than 10% compared with the previous cycle, coordinated output is out of sync, or power fluctuation is aggravated; If an abnormality is detected, the threshold of each sensitive factor is adjusted proportionally by no more than ±15% based on the five sensitive factors of the current cycle: beam focus offset speed, spot area change rate, film thermal stress growth rate, local refractive index gradient change, and receiving area temperature gradient amplitude, combined with the energy loss ratio. The revised sensitivity factor thresholds were used to update the focus shift discriminator parameter set, including adjusting the spot area expansion rate to 1.4 mm² / min, the film stress growth threshold to 9.2 MPa / min, and the hot spot temperature gradient warning value to 14°C / cm. Simulation sequences were used to verify whether the new parameters could trigger correction instructions before the shift reached the 70% threshold. The updated parameters are encapsulated as the current running version, and the changes in the photothermal output synchronization rate, focus drift response time, focus return speed, and energy loss are monitored in the next two operating cycles. If the energy efficiency improvement is no less than 8% and the misjudgment rate does not exceed 5%, the parameter update is confirmed to be valid and will continue to be used in subsequent control strategies.

[0013] A solar spectrum frequency division cogeneration system includes a coupling modeling and analysis module, an offset criterion extraction module, a focus offset discrimination module, a dynamic spectrum adjustment module, a collaborative closed-loop control module, and a strategy optimization and evaluation module: The coupled modeling and analysis module establishes a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. It collects real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions, and generates an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. The offset criterion extraction module identifies the thermal lens sensitivity factor that causes the spot offset based on the estimated atlas of the refractive index gradient distribution, extracts the corresponding spot offset threshold, film stress threshold, and focus tolerance, and uses this to establish physical constraints for determining the beam offset state; The focus shift discrimination module builds a focus shift discriminator based on physical constraints, inverts the real-time focus coordinates based on the beam wavefront information, calculates the corresponding energy flux density, and classifies the degree of spot shift into a grade label; The dynamic spectrum adjustment module dynamically adjusts the spectrum splitting path according to the spot offset level label, realizes spectrum reconstruction by adjusting the incident angle and bandpass width, and drives the flexible micro-actuator to perform optical axis correction operation, so that the reconstructed light beam is stably projected to the predetermined energy receiving area; The collaborative closed-loop control module feeds back the operating status of the optical axis correction and spectral splitting adjustment to the thermal management system. Based on the heat distribution in the energy receiving area, it applies liquid cooling flow pulses and switches the phase change heat conduction channel. It also adjusts the absorptivity of the crossover surface coating to achieve a collaborative closed-loop operation of optical path adjustment and thermal management control. The strategy optimization and evaluation module evaluates the overall operation effect of the system based on the energy output data of collaborative closed-loop operation, adaptively corrects the threshold of the thermal lens sensitivity factor based on the evaluation results, and updates the parameters of the focus shift discriminator to achieve dynamic optimization of the thermal lens suppression strategy.

[0014] In the above technical solution, the technical effects and advantages provided by the present invention are: The present invention achieves accurate prediction of the thermal lens formation mechanism by establishing a coupling relationship between the beam wavefront, temperature distribution, and refractive index change. It also ensures real-time identification and classification of focus drift states through the extraction of thermal-sensitive factors and the construction of an offset level discriminator. Furthermore, by combining spectral path reconstruction, incident angle adjustment, and flexible optical axis calibration, the beam offset is dynamically corrected to maintain the alignment accuracy of the photoelectric and photothermal paths. At the same time, the adjustment results are fed back to the thermal management operation, combining cooling flow control, thermal path switching, and surface coating adjustment to achieve coordinated stability of the photothermal path. Finally, under a closed-loop evaluation mechanism, parameters are continuously adaptively updated to achieve continuous optimization and self-evolutionary control of the thermal lens suppression strategy. The overall solution runs through the collaborative control path of the three-dimensional physical fields of heat, light, and force, forming a closed loop from source identification, path correction, to terminal feedback. This effectively ensures the energy acquisition stability and output power consistency of the photovoltaic unit and the thermal collector during long-term operation, overcoming the energy efficiency fluctuations, load imbalance, and device damage caused by thermal lens runaway in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction to the drawings required for use in the embodiments will be given below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0016] Figure 1The present invention is a method flow chart of a solar spectrum frequency division cogeneration operation method.

[0017] Figure 2 This is a module schematic diagram of a solar spectrum frequency division cogeneration system of the present invention. DETAILED DESCRIPTION

[0018] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that the description of this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art.

[0019] The present invention provides Figure 1 A solar spectrum frequency division cogeneration operation method is shown, comprising the following steps: S001: Establish a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. Collect real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions. Generate an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. To address the thermal lensing effect of solar spectrum splitting devices under high-energy irradiation conditions, and to quantitatively analyze and predict their thermo-optical behavior, a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties was constructed, and an estimated map of the refractive index gradient distribution was generated based on this. The method includes the following steps: A simulated full-spectrum solar irradiation environment was constructed and an irradiation experiment was conducted on the spectrum divider to obtain its true temperature response under working conditions. Specifically, a xenon lamp solar simulator with an output capability in the wavelength range of 300nm to 2500nm was selected as a stable spectral irradiation source, and the output beam was focused onto the test sample by adding a quartz collimating lens and a coated parabolic reflector combination device. The test sample is a multilayer film spectrum divider with a 12-layer structure, in which the dielectric materials included include high-refractive index material titanium dioxide, low-refractive index material silicon dioxide and zirconium oxide with medium thermal conductivity. The thickness of each film layer is controlled within the range of ±5nm, and the total film thickness is about 2μm, which are deposited on an optical-grade fused quartz substrate. In order to collect the temperature response of the divider under high-power density irradiation conditions, a temperature measurement structure combining a thermistor sheet and a non-contact infrared thermometer is installed in the central area, edge area and internal sandwich structure of its surface. The infrared thermometer uses a high-sensitivity model with a measurement range of 0°C to 300°C and a response time of less than 20ms, ensuring real-time recording of the temperature rise caused by focused radiation. Real-time data from all temperature acquisition nodes is transmitted to the upper processing platform via an acquisition card at a 1Hz frequency, running continuously for at least 30 minutes to obtain dynamic temperature distribution data.

[0020] After acquiring the temperature response, the optical output characteristics of the spectral divider during irradiation were further simultaneously acquired, focusing on recording the changes in the outgoing beam wavefront at different time points. To achieve high-resolution wavefront capture, a wavefront detection device with precise pixel positioning was placed directly opposite the beam transmission path. This device uses a microlens array as the front receiving surface. By imaging the local deflection angle of the transmitted beam in real time, the phase distortion of the beam can be inferred. With a spatial resolution of 5μm and a sampling rate of 30 frames per second, the device can record the curvature, convexity, and tilt distortion of the wavefront at different time points. To ensure the physical authenticity of the sampled wavefront data under high irradiation densities, a heat-blocking filter was installed at the front of the wavefront sensor during the experiment to prevent secondary deformation caused by thermal effects. At the timestamp corresponding to each temperature sampling point, complete wavefront information was synchronously acquired at that moment, forming a temperature-wavefront time series data pair that provides the input for subsequent optical response modeling.

[0021] Based on the above temperature data and wavefront data, the refractive index changes of each layer of the frequency divider under the corresponding temperature conditions are calculated layer by layer, and its spatial refractive index distribution spectrum is reconstructed. Taking titanium dioxide as an example, its thermo-optical coefficient range is , silicon dioxide is , zirconium oxide is , combined with the actual measured temperature of each temperature sampling point, the total refractive index change value at different spatial positions after the multilayer film is stacked is obtained by layer-by-layer superposition. The refractive index change values ​​corresponding to all temperature points are spatially mapped to construct a refractive index gradient field in a three-dimensional coordinate system. The coordinate axes are the horizontal X direction, vertical Y direction and thickness direction Z of the divider. By directly expanding the corresponding relationship between the refractive index change value and time at each coordinate point, it can be observed that near the center of the high-energy irradiation area, the refractive index change shows an obvious nonlinear distribution, and it is highly overlapped with the wavefront distortion area, verifying that heat accumulation has a substantial impact on the optical output. This step does not rely on computational approximation or empirical simplification. All deductions are based on physical constants and measured temperature values ​​to ensure that the results are engineering reliable.

[0022] Based on the refractive index gradient data, the spatial variation trend is further visualized and a highly recognizable atlas is constructed to assist in the subsequent thermal lens risk assessment. By projecting the three-dimensional refractive index variation data along the Z axis, multiple isosurface maps are generated, and different gradient intervals are marked by piecewise linear color mapping to form a distribution map that intuitively displays the refractive index variation. The area is marked as a high-risk area. This threshold is set based on experimental observations that in actual systems, focus drift exceeding 0.5 mm may cause the light spot to deviate from the preset receiving position. The atlas not only provides the distribution of spatial thermo-optical properties, but also provides an intuitive physical reference for determining the initial conditions and risk areas for thermal lens formation, facilitating subsequent identification methods to accurately locate the source of the offset. While forming the atlas, it is spatially aligned with the wavefront distortion data to determine whether the atlas prediction area matches the actual beam distortion area, in order to verify the accuracy and applicability of the modeling method.

[0023] This step aims to provide a quantifiable, verifiable, and traceable physical analysis basis for the thermally induced optical distortion (TIOD) problem in solar spectrum frequency-splitting cogeneration. By establishing a coupled analysis baseline between irradiation parameters, heat distribution, and optical output characteristics, it enables early identification and risk assessment of potential non-uniform refractive index variations in the spectral frequency divider under high-intensity irradiation conditions. Specifically, under concentrated solar irradiation, the spectral frequency divider absorbs light energy from different wavelengths, generating non-uniform temperature rises within its structure. This is particularly true in multilayer coating structures, where significant differences in thermal conductivity, thermal expansion coefficient, and thermo-optical constants among different materials can easily lead to temperature gradients perpendicular to the film layers and in-plane directions. This further triggers nonlinear variations in the refractive index at various locations, causing beam propagation path deflection and the so-called thermal lensing effect. If this phenomenon is not predicted and controlled, it can lead to offsets in the photoelectric and photothermal conversion paths, resulting in reduced reception efficiency, unstable energy utilization, and even system safety hazards.

[0024] The refractive index gradient distribution map established by this step can not only accurately locate high-risk areas for thermal distortion, but also provide a spatial prediction basis for optical offset, serving as an important reference parameter for subsequent identification of light spot drift, adjustment of the spectroscopic path, and execution of optical axis correction. At the same time, as an intermediate variable with physical significance, the map establishes a causal chain from irradiation energy input to beam output offset, which helps to improve the controllability and robustness of the entire cogeneration system in the design, control, and operation stages. Therefore, this step plays a fundamental role in connecting the preceding and following stages in the present invention. It is a key prerequisite for the effective operation of a series of mechanisms such as subsequent thermal lens sensitivity factor identification, offset state discrimination, and dynamic control execution. It is also an important construction link for realizing a quantitative suppression strategy for thermal lens problems.

[0025] S002: Based on the estimated atlas of the refractive index gradient distribution, identify the thermal lens sensitivity factor that causes the spot offset, extract the corresponding spot offset threshold, film stress threshold, and focus tolerance, and use this to establish physical constraints for determining the beam offset state; Based on the previously constructed refractive index gradient distribution map, in order to further identify the main thermal mechanism causing the spot shift, a multi-dimensional physical parameter extraction method was used to carry out the determination process of the thermal lens sensitivity factor. Combined with the measured thermal-optical coupling characteristics, physical judgment criteria including the spot shift threshold, film stress threshold, and focus tolerance were proposed. The specific steps include: Based on the spatial area with obvious non-uniform refractive index changes in the refractive index gradient distribution map, the heat-sensitive positions that may cause beam distortion are screened. In the above map, the positions that appear in the central irradiation area and the edge transition area, where the refractive index gradient change value exceeds per millimeter. This threshold is set after comparison with the actual wavefront detection data, that is, when the rate of change of the refractive index at a certain position is greater than the threshold, it usually corresponds to a sudden change in curvature in the wavefront diagram, indicating that the beam propagation path is deflected in this area. After identifying the area, the temperature sampling point data that coincides with it in space are extracted, and the temperature evolution trends of these points in the initial, middle and stable stages of irradiation are compared and analyzed. The results show that the temperature peaks of these areas in the stable stage of illumination are generally higher than the average temperature of the device by about 15°C to 25°C, and the temperature difference of some high points exceeds 30°C, indicating that heat has accumulated significantly at these locations. These characteristics show that the areas with large refractive index changes are the sensitive sections in the beam propagation trajectory that are prone to deflection, and are an important physical basis for judging the risk of thermal lensing.

[0026] Within the identified heat-sensitive region, the material structural parameters of the spectrum divider film layers were extracted, and the internal stress distribution induced by temperature rise was calculated to determine the critical stress range that causes spot shift. For example, the 12-layer spectrum divider used in the experiment consists of alternating deposits of titanium dioxide and silicon dioxide, with each layer thickness controlled between 110nm and 180nm, for a total film thickness of 1.8μm. In the central irradiated area, the temperature rise causes in-plane tensile stress in the titanium dioxide layer, while the silicon dioxide layer exhibits compressive stress due to its smaller thermal expansion coefficient. Using high-precision strain gauges and non-contact digital image correlation, the sample surface microdisplacement was measured before and after illumination. Combined with the Young's modulus and Poisson's ratio of the material, the equivalent stress range within the film layers was inferred. The measured stress range for the central film layer was 52MPa to 115MPa. Stress values ​​exceeding 65MPa clearly correlate with spot shift observed in the wavefront distortion image. Further repeated experiments were carried out under different power density irradiation conditions, and the spot center offset was paired with the stress value for analysis. It was concluded that 65MPa was the lower limit of stress that caused significant spot offset, and thus the film stress threshold was established as 65MPa.

[0027] While obtaining the stress threshold of the film layer, the energy concentration distribution during the beam focusing process is analyzed to clarify the allowable deviation range of focusing and determine the geometric tolerance that the system can tolerate. To this end, the energy of the spot shape after thermal offset is measured at different receiving plane positions. The light intensity distribution is measured at the center of the optical axis and at different offset distances using a laser power meter and a thermal receiving plate. The light intensity changes at each point are recorded at 0.1mm, 0.3mm, 0.5mm, 0.7mm and 1.0mm from the center under the condition of a focusing distance of 800mm. The experimental results show that when the offset distance exceeds 0.6mm, the received energy density decreases by more than 17%, which has affected the synchronous matching of photovoltaic conversion efficiency and thermal energy reception. Therefore, the focusing tolerance is set to within 0.6mm. This focusing tolerance defines the acceptable degree of deviation of the center position of the light spot and is an important boundary parameter for subsequently judging whether the light beam deviates from the predetermined trajectory.

[0028] Combining the light spot offset threshold, film stress threshold, and focusing tolerance obtained above, a set of physical constraints was established to determine the beam offset state. In this process, a composite judgment criterion was selected that required two criteria to be met simultaneously to determine that the offset state was established: first, the light spot center offset distance exceeded 0.6mm; second, the equivalent stress of the film layer in the corresponding area was greater than or equal to 65MPa. At the same time, it was required that this judgment must occur within the aforementioned thermal sensitive area and be displayed as a change value greater than 0.6mm in the refractive index gradient map. A triple verification mechanism ensures that the offset determination results are physically interpretable and structurally consistent. In specific applications, when any position in the collected real-time operating data simultaneously meets the above three physical conditions, it can be determined that the beam has experienced focus drift induced by thermal lensing. This identification result can be used as a trigger for subsequent path reconstruction and optical adjustment.

[0029] This step aims to identify the key thermal lens sensitivity factors that directly cause beam spot deviation in the spectral splitter through in-depth analysis of the spatial distribution of thermally induced refractive index variations. Based on this, a series of physical boundary parameters with engineering constraints are extracted, establishing a stable and quantifiable basis for subsequent beam deviation state identification and path correction mechanisms. In solar spectral splitting cogeneration systems, beam deviation is not caused by a single factor but rather by the combined effects of multiple thermal, mechanical, and optical factors. Among these, film stress response, refractive index gradient variation, and focus deviation are the three most significant variables. This step addresses this coupling issue. Through field measurement and analysis, it identifies the locations, material layers, and thermal conditions within the spectral splitter that are most likely to produce refractive index anomalies sufficient to alter the optical path under actual high-power irradiation conditions. Furthermore, it defines the extent of thermal stress within the film, the extent of beam spot deviation, and the degree of focus loss within these regions that trigger the system to enter an abnormal state of optical path deviation. By setting clear "spot offset thresholds," "film stress thresholds," and "focus tolerances," the fuzzy "offset phenomenon" is transformed into an objective physical state that can be measured, identified, and determined, establishing a complete chain of physical criteria for beam offset. This criterion not only serves as a basis for subsequent real-time state recognition and control decision-making, but more importantly, it enhances the system's ability to predict and accurately respond to abnormal conditions. This significantly differs from existing technologies that rely on subjective mechanisms based on empirical settings or image change judgments, achieving an engineering closed loop from thermally induced changes to offset control. It serves as a crucial intermediate link and basis for determination in the entire thermal lensing effect suppression mechanism.

[0030] S003, constructing a focus shift discriminator based on physical constraints, inverting the real-time focus coordinates based on the beam wavefront information, calculating the corresponding energy flux density, and classifying the degree of spot shift into a grade label; Based on the established physical constraints of spot shift, by collecting and analyzing the wavefront information of the light beam, a focus shift discrimination method is further established to determine whether the focus has spatially shifted. Combined with the energy flux density measurement results, the spot shift state is graded, thus providing a basic judgment basis for the subsequent spectral diversion adjustment strategy. The method includes the following steps: A wavefront information acquisition device is arranged on the exit path of the spectral frequency divider to obtain the wavefront variation of the exit light beam under the solar irradiation condition. The wavefront detection of the light beam uses a microlens array type wavefront sensor, which is composed of square microlens units with a size of 150 μm. The overall detection surface size is 15 mm x 15 mm, and the spatial resolution is 100 sample points per millimeter. The wavefront sensor is placed on the main axis in the exit direction of the spectral frequency divider, about 300 mm away from the frequency divider, so as to accurately collect the wavefront distortion pattern of the exit light beam after the frequency divider. After the irradiation process starts, the solar simulator continuously outputs simulated light with a power density of 800 W / m². The wavefront sensor collects the two-dimensional phase distribution map of the current light beam at a frequency of 20 frames per second. By analyzing the concave-convex curvature, main optical axis twist and phase discontinuous area in the wavefront, it can be identified whether the light beam has occurred deflection caused by thermal induced refractive index inhomogeneity. When the main optical axis deviates more than 0.2 mm in the X or Y direction, it is preliminarily determined that the focal point has spatial drift, and the next step of accurate focal point positioning is needed.

[0031] After confirming the possible deviation of the light beam, the actual focal point spatial coordinates of the light beam are derived according to the wavefront data, and the physical light path backtracking method is used to calculate the positions of the focal point in the X, Y and Z directions in the three-dimensional space. The specific implementation is as follows: through the density and distribution trend of the phase contour in the wavefront map, combined with the focal length parameter (the initial focusing distance used in this embodiment is 800 mm), according to the geometric optical imaging principle, the relationship between the light beam exit angle and the focal length is physically mapped to obtain the actual deviation distance between the current focal point position and the theoretical reference focal point. For example, when the equal phase surface at the center of the wavefront changes from a spherical surface to an asymmetric ellipsoid, it indicates that the focal point has a displacement in the Z axis direction. When the wavefront center deviates from the geometric center of the detection surface by more than 0.4 mm, it indicates that there is a focal point translation in the X or Y direction. This process does not depend on mathematical inversion formula, but is completely based on the relationship between wavefront map physical feature extraction and light path tracking to realize the real restoration of the focal point spatial coordinates.

[0032] After obtaining the focal position, a receiving device is arranged on the plane where the focal point is located to make a spatial measurement of the energy flux density at the position. The receiving device uses a planar receiving plate with a thermal response layer, which is a high-stability liquid crystal temperature-sensitive film with a thickness of 100 pm, an operating response range of 30°C to 90°C, a temperature measurement accuracy of ±0.2°C, and a response time of less than 300 ms. The thermal response film is matched with a high-resolution infrared thermal imager to record the two-dimensional thermal distribution of the light beam at the focal point in the X-Y plane. The energy flux density distribution is obtained by pixel gray scale inversion, and the influence of the spot shift on the focusing quality is judged according to the energy concentration degree. For example, when the energy is concentrated in an area with a diameter of less than 1.2 mm and the maximum heat flux density is higher than 400 W / m2, it indicates that the focusing is good; if the heat zone spreads outward and the concentration degree decreases to below 70% and the focal point diameter expands to more than 2.0 mm, it indicates that the thermal lens causes the focusing performance to decrease. The data will be used as basic parameters to evaluate the degree of influence of the focal point shift, and together with the focal point coordinate data, it will form the basis for the next step of grade division.

[0033] The focal point shift distance and the energy flux density concentration degree are used as joint criteria to divide the spot shift grade under the current state according to the aforementioned physical constraints of spot shift. In this embodiment, the spot shift degree is divided into five grades, each corresponding to a specific optical axis deviation distance, focal point diffusion radius, and energy flux density loss ratio. The specific division is as follows: the first grade is the normal focusing state, the focal point shift is less than 0.2 mm, the focal point radius is less than 1.2 mm, and the energy concentration degree is higher than 90%; the second grade is the slight shift state, the focal point shift is between 0.2 mm and 0.4 mm, the focal point radius is between 1.2 mm and 1.5 mm, and the concentration degree is between 85% and 90%; the third grade is the moderate shift, the shift is between 0.4 mm and 0.6 mm, the focal point radius is between 1.5 mm and 1.8 mm, and the concentration degree is between 80% and 85%; the fourth grade is the severe shift, the shift exceeds 0.6 mm, the focal point radius is between 1.8 mm and 2.5 mm, and the concentration degree is lower than 80%; the fifth grade is the extreme shift, the shift exceeds 1.0 mm, the focal point appears double focal points or a twisted ring structure, and the energy flux density distribution is discontinuous. The grade label is used to identify the running deviation state of the current light beam and serves as a direct basis for triggering subsequent dynamic light path adjustment, incident angle correction, and thermal management linkage operations.

[0034] The role of this step is to provide a real-time discrimination method based on physical measurement and thermal-optical coupling behavior identification for the possible focal point drift and energy flow offset problems caused by uneven heating and internal refractive index distribution changes of the spectral frequency divider during the operation of the solar spectrum frequency division combined heat and power device, thereby achieving effective identification and quantitative division of the light spot offset state. Specifically, when sunlight passes through the multi-layer film spectral frequency divider, due to the differences in the thermal expansion coefficient, refractive index thermal sensitivity coefficient and structure thickness of different film layers, local refractive index abnormalities are easily caused under high-intensity irradiation conditions, forming thermal lens effect, and then changing the light beam propagation path and distorting the wavefront structure, so that the originally precisely focused light beam is offset in space. If this offset cannot be identified in time, not only will the photovoltaic cell not receive enough visible light radiation, but also the thermal energy conversion unit will not be able to obtain high-density infrared energy, thereby causing the imbalance of the electric and thermal output and reducing the overall system efficiency.

[0035] Therefore, based on physical light path analysis, this step first accurately measures the phase distortion of the light beam in space through the wavefront sensor, and then deduces the actual coordinate position of the focal point, and further quantitatively analyzes the focusing deviation of the light beam in combination with the energy flow density distribution at the focal point. By setting physical judgment thresholds such as focal point offset distance, energy flow density drop ratio, and focusing area expansion degree, the offset level label of the light spot is further divided, so that different degrees of offset state can be clearly identified and used as the trigger basis for subsequent control actions. Unlike the existing technology which relies on image recognition or empirical parameters for fuzzy judgment, this step constructs a complete and repeatable physical criterion chain, ensuring that each offset identification has clear data support and physical background, improving the accuracy, stability and response efficiency of the system operation.

[0036] More importantly, the offset discrimination process is not limited to theoretical modeling or software simulation, but realizes a full-process closed loop through the wavefront data collected by the real sensor and the thermal response image, which has strong engineering feasibility. Finally, this step not only provides a decision basis for dynamically adjusting the spectral flow path, performing optical axis correction and focal point reconstruction, but also realizes a closed loop chain from state perception, offset judgment to response control through the coordination of the offset level label and the subsequent thermal management control strategy, which is one of the key links for the invention to realize active inhibition of thermal lens effect.

[0037] S004, according to the light spot offset level label, dynamically adjusting the spectral flow path, realizing spectral reconstruction by adjusting the incident angle and the band width, and driving the flexible micro-actuator to perform optical axis correction operation, so that the reconstructed light beam is stably projected to the predetermined energy receiving area; Based on the spot offset level label obtained through the aforementioned beam wavefront inversion and energy flux density calculation, in order to achieve adaptive reconstruction of the spectral splitting path under the influence of thermal lensing, three methods are further used to work together: incident angle fine-tuning, spectral bandpass width adjustment, and optical axis position correction to ensure that the adjusted beam can still accurately fall into the target energy receiving area. The entire implementation process includes the following steps: The light spot offset level label is used to determine whether spectral path adjustment is required and what type of adjustment instruction needs to be executed. In this embodiment, the light spot offset is divided into five levels, where level one is the normal operating state and does not trigger any adjustment operation; level two is a slight offset state and only triggers the incident angle fine-tuning operation; level three and above indicate that the focus has shifted significantly and the incident angle adjustment, bandpass width adjustment and optical axis correction operations need to be performed simultaneously. For example, when the focus offset distance is greater than 0.6mm, the focus diameter is expanded to more than 1.8mm, and the energy flux density loss exceeds 15%, it can be determined as a level four offset and the comprehensive adjustment process is immediately initiated. After determining the adjustment level, the preset adjustment parameter group is called to determine the incident angle change value to be applied, the filter film thickness adjustment range, and the optical axis rotation angle range.

[0038] The incident angle adjustment is performed to adjust the angle of the incident light before it enters the spectral splitter, thereby controlling the projection direction of the beams of different wavelengths. The incident angle control device used is a tiltable reflector composed of a high-reflectivity silver-coated aluminum layer with an anti-oxidation protective layer. The reflector measures 50 mm x 50 mm and is 3 mm thick. It is mounted on a three-dimensional adjustment bracket. The bracket houses two piezoelectric ceramic drive units, which control the mirror's tilt in the X and Y directions, respectively. The angle can be fine-tuned by 0.05° per step, with a maximum adjustment range of ±3°. For example, when the offset level is set to level three, the angle adjustment is ±0.5°; when the offset level is set to level four, the angle adjustment is ±1.2°. By adjusting the reflector's tilt, the direction of the solar simulator's output beam is slightly altered, thereby adjusting the main angle of incidence of the beam received by the spectral splitter, allowing the originally deflected light to fall back onto the photovoltaic or solar thermal receiving surface.

[0039] In addition to adjusting the angle of incidence, the passband width is further adjusted to optimize spectral selectivity and prevent overlap or mismatch of energy across different wavelengths at the receiving location. This embodiment utilizes an adjustable interference filter structure. The filter is constructed from multiple dielectric layers, consisting of alternating deposits of titanium dioxide (high refractive index) and silicon dioxide (low refractive index), with a total film thickness of 2.5 μm. The filter is attached to a quartz glass substrate and mounted on a slide support. A piezoelectric micro-actuator can be used to control the film thickness within a ±50 nm range, enabling a ±10 nm adjustment range for the passband center wavelength and a ±5 nm adjustment range for the bandwidth. When the offset level reaches level three or above, the passband bandwidth is reduced, for example, from the original 30 nm to 25 nm or 20 nm. This prevents focus shift from causing partial spectral spillover into non-target areas, resulting in energy waste or interference. This adjustment refocuses some off-center spectral energy within the controllable wavelength range, improving diversion efficiency.

[0040] After adjusting the incident angle and controlling the spectral bandwidth, a micro-scale position correction along the optical axis is performed to return the deflected beam path to the designed optical path in terms of spatial geometry. The optical axis correction structure used consists of a set of flexible micro-displacement actuators. The core structure consists of a 30 mm × 30 mm metal platform supported by four flexible hinges and made of aluminum alloy with an anodized surface. Two piezoelectric ceramic actuators are positioned beneath the platform, controlling micro-displacement adjustments in the X and Y axes, respectively. Each adjustment step is 2 μm, with a maximum adjustment range of ±100 μm. When the deviation level is determined to be level three or above, the actuators perform proportional angle adjustments, for example, a ±1° angle correction for level three and a ±2° angle correction for level four. This angle correction ensures that the beam is perpendicular to the receiving surface in the outgoing direction, ensuring that the reconstructed beam is projected at the optimal angle onto the photovoltaic array or thermal absorber. The corrected beam landing offset is controlled within ±0.2 mm, ensuring continued stable system operation.

[0041] The role of this step is to quickly and accurately adjust the spectral splitting path based on the determined spot offset level when the light beam is spatially offset, the focal point drifts or the spectral energy is misaligned due to thermal lens effect during the operation of spectral frequency heat and power cogeneration, to ensure that the light beams of different wavebands can still be effectively projected to the photovoltaic power generation unit and the light-thermal conversion unit, thereby maintaining the continuity, stability and efficiency of the electric-thermal collaborative output. Under the condition of concentrated solar radiation, the spectral frequency divider is easily offset due to the non-uniform change of the internal refractive index after being subjected to high-intensity thermal excitation. This offset not only changes the propagation direction of the light beam, but also causes the different waveband light energy to not accurately fall into the target receiving area, thereby destroying the energy distribution strategy of photoelectric and photothermal in the system design and reducing the overall energy utilization efficiency.

[0042] To solve this problem, this step realizes the dynamic reconstruction of the spectral path through three specific operations: first, the incident light direction is changed by the incident angle adjusting device, so that the offset light beam can re-enter the optimal working area of the spectral frequency divider; second, the spectral bandwidth and center wavelength of the band-pass filter layer are adjusted to redivide the energy wavebands in the transmission and reflection paths, avoiding spectral energy leakage or misplacement due to waveband diffusion or offset; finally, the optical axis direction is finely adjusted by the flexible micro-displacement actuator, so that the adjusted light beam is re-aligned with the photovoltaic cell array or the heat energy absorption plate in space, realizing high-density and high-precision light energy projection. The three operations cooperate with each other to actively compensate for the offset state from the three dimensions of light incidence, spectral selection and optical axis spatial direction, ensuring that the system can maintain the light beam alignment accuracy and spectral splitting efficiency under the influence of thermal lens.

[0043] Compared with the way of dealing with offset problems in the prior art by passive structure adjustment or optical tolerance design, the present application establishes a dynamic adjustment mechanism with fast response speed, high adjustment accuracy and clear control logic by combining active sensing with physical action, not only realizes real-time reconstruction of the spectral splitting path, but also significantly improves the robustness and intelligent level of the system in complex operating environment. Therefore, this step plays an important role in the whole thermal lens suppression technology path and is a key control bridge connecting the offset identification result and the subsequent thermal and optical regulation operation.

[0044] S005, the operating state after the optical axis correction and spectral splitting adjustment is fed back to the thermal management system, the liquid cooling flow pulse is applied and the phase change heat conduction channel is switched based on the heat distribution of the energy receiving area, and the absorptivity of the frequency divider surface coating is adjusted to realize the collaborative closed-loop operation of optical path adjustment and thermal management control; To further enhance the operational stability and energy scheduling accuracy of the solar spectrum splitting combined heat and power device in the focal point offset state, after completing the optical axis correction and spectral splitting path adjustment, the energy flow distribution, offset response amplitude, and focal point position change information in the current operating state are fed back to the heat management control link. According to the distribution of the actual heat landing area, a closed-loop control mechanism is constructed by executing liquid cooling flow pulse control, phase change heat conduction path switching, and absorption coating absorption rate adjustment operations, which coordinates the optical adjustment and heat load adjustment. The process includes the following steps: After the optical axis correction and spectral path reconstruction are completed, the heat change detection process of the receiving surface is immediately started to obtain the heat load distribution after energy refocusing. The detection process is completed by a thermocouple array and an infrared thermal imaging device arranged behind the photovoltaic module back and the heat absorbing surface. The thermocouple uses K-type wire with a diameter of 0.3mm and an installation spacing of 10mm, which is connected to a high-precision temperature acquisition module with a sampling period of 500ms. The infrared thermal imaging device is FLIRA615, with an infrared resolution of 640x480, a thermal sensitivity of 0.05°C, and an acquisition frequency of 10 frames per second. After each optical axis adjustment cycle is completed, the infrared image and temperature acquisition value are uploaded synchronously, spatial matching is performed, and the two-dimensional temperature distribution map and temperature rise trend of the receiving surface are obtained. When it is detected that the focal point is focused too much on the photovoltaic receiving surface, the center temperature continuously exceeds 50°C, and the peripheral temperature remains within 30°C, it indicates that the energy landing point has formed a local heat concentration state, which is used as a signal to trigger the subsequent thermal response action.

[0045] According to the identification result of the heat concentration area, a short-time high-flow pulse is applied to the liquid cooling structure to quickly remove the locally accumulated heat and prevent the generation of hot spots or the secondary induction of thermal lenses. The liquid cooling structure uses a straight-through type multi-tube liquid cooling plate with 18 parallel arranged micro-channel copper pipes embedded inside, with an inner diameter of 1.5mm and a flow channel spacing of 12mm. The cooling medium is deionized water with an inlet temperature controlled at 18°C. The cooling plate inlet is connected to an electric diaphragm pump with a maximum flow rate of 600mL / min. The pump control circuit receives the area and temperature rise value calculation results from the thermal center position in the thermal imaging image analysis results, and automatically triggers the pulse cooling instruction when the center area temperature rise amplitude exceeds 10°C. When executing cooling, the original set flow rate is instantaneously increased from 300mL / min to 450mL / min, and the pulse duration is 5 seconds. The flow pulse forms a transient heat exchange enhancement zone through impingement convection mechanism, effectively diffuses the focal point heat to a larger area, improves the overall heat dissipation rate, and avoids local thermal expansion and contraction induced material distortion.

[0046] After completing the liquid cooling pulse operation, the heat distribution differences in different areas of the hot surface are analyzed, and the heat conduction path switching of the phase change heat conduction structure is controlled accordingly to further improve the thermal conductivity balance of the deep structure. The heat conduction structure used in this embodiment includes two types of phase change units. The first type is a paraffin-based material encapsulated in an aluminum cavity with a melting point of 46°C and a latent heat of 210kJ / kg; the second type is an indium tin alloy block with a melting point of 78°C and a latent heat of 88kJ / kg. Both types of materials are laid in rectangular blocks at the rear of the heat absorption surface and are in direct contact with the copper base plate. The switching operation is controlled by a thermal switch, which is set as follows: when the temperature of the monitoring area fluctuates between 45 and 55°C, the paraffin heat conduction block channel is activated; when the temperature continues to rise and approaches 80°C, the indium tin channel is activated to achieve higher heat flux release. The switching of the heat conduction path is completed in no more than 8 seconds. It relies on a two-way temperature difference excitation reaction to ensure timely transfer of the heat conduction path when the heat load suddenly changes, maintain a balanced thermal stress distribution of the overall structure, and reduce local thermal deformation caused by excessive transient thermal gradients.

[0047] After the thermal load management operation is completed, the performance of the selective absorption coating on the surface of the spectrum divider is adjusted based on the feedback of the focus offset level and the thermal distribution of the receiving surface to enhance the beam path stability and reflection interference suppression capabilities. The coating used in this embodiment is a multilayer absorption film composed of a chromium oxide black layer and a silicon nitride control layer. The chromium oxide layer is 90nm thick and the silicon nitride layer is 130nm thick. Its absorption rate is 88%-91% in the visible light band and 68%-73% in the near-infrared band. The coating is deposited on the substrate glass on the front surface of the spectrum divider and fine-tuned by a temperature-controlled heater. The heater is located on the back of the coating and is composed of a graphite film, which can achieve a surface temperature control accuracy of ±5°C. If the temperature in the center of the receiving thermal focus area rises too quickly, the coating surface temperature is moderately increased to fine-tune the lattice constant of the silicon nitride layer, thereby changing the surface microstructure and improving the absorption rate by less than 2%. This absorbs more mid- and far-infrared radiation and reduces the amount of light energy that is not fully converted and reflected back into the optical path. In addition, when the offset level is level four or five, the increased absorption rate and thermal conductivity adjustment work together to effectively maintain focus stability and buffer energy fluctuations during the offset process.

[0048] The purpose of this step is to establish a closed-loop synergistic relationship between optical path adjustment and thermal management control in a solar spectrum-splitting cogeneration system. This allows the operating state after optical axis correction and spectral splitting reconstruction to effectively reverse the heat scheduling mechanism, achieving dynamic response and elimination of local heat load accumulation, ultimately maintaining the system's photothermal balance and stable operation under high-irradiance and focus-shift environments. Under high-intensity sunlight conditions, the thermal lensing effect can easily cause beam focus shift. Even if the beam path is realigned in the previous steps through means such as incident angle adjustment, bandpass width control, and optical axis micro-displacement adjustment, the refocusing of light energy on the target receiving area often causes a rapid increase in local temperature rise, forming a new hot spot. If this heat concentration state is not promptly responded to and dynamically intervened, it may cause thermal stress deformation of optical components, degradation of material properties, and even induce secondary refractive index perturbations, which in turn interfere with optical axis stability and spectroscopic accuracy, undermining the system's closed-loop control effect.

[0049] Therefore, this step constructs a complete feedback logic pathway of "optical behavior → thermal distribution change → thermal control response." Liquid-cooled flow pulses precisely reduce the thermal peak at the center of the spot, preventing damage to the receiving components from transient thermal shock. By switching between different types of phase-change thermal conductive materials, heat flux adaptation for different temperature ranges is achieved, effectively alleviating local thermal deformation caused by excessive thermal gradients. By fine-tuning the selective absorption coating on the surface of the spectrum divider, energy reflection interference and heat retention are further controlled, thereby achieving a rebalance between active dissipation in high-energy-density areas and the stability of the optical-thermal path. Throughout the entire process, each operation is based on the focal position, offset level, and thermal distribution state obtained after correction in the previous step, ensuring precise thermal management, fast response, limited and efficient adjustment, and no additional disturbance to the optical path.

[0050] Compared to the isolated operation of thermal management and optical path regulation in traditional cogeneration systems, this step achieves real-time linkage between physical energy path adjustments and thermal regulation through feedback-based collaborative construction, forming an intelligently responsive and self-adaptive multi-energy coupling control mechanism. This mechanism not only improves the overall energy efficiency of the system but also significantly enhances the device's operational robustness in dynamic climates and complex load conditions. It is a key step in achieving the dynamic suppression of thermal lensing and the stable operation of synergistic photothermal output.

[0051] S006: Based on the energy output data of the collaborative closed-loop operation, the overall operation effect of the system is evaluated. Based on the evaluation results, the threshold of the thermal lens sensitivity factor is adaptively corrected and the parameters of the focus shift discriminator are updated to achieve dynamic optimization of the thermal lens suppression strategy. In order to improve the adaptive control capability of the solar spectrum frequency division cogeneration device in complex operating environments, after completing the aforementioned spot focus adjustment, spectral path reconstruction and thermal management coordinated closed-loop control, a comprehensive evaluation of the overall operating effect is conducted based on the power and thermal energy output data during the operating cycle, and then the dominant influencing factors of the thermal lens effect are identified. Based on this, the relevant parameters are adaptively corrected and the focus offset judgment conditions are updated, thereby achieving dynamic optimization of the thermal lens suppression strategy and improving the control accuracy of the photothermal path stability under high temperature and strong light interference. The whole process includes the following steps: Collect and process photovoltaic and thermal output data for a complete operating cycle to evaluate the current energy conversion efficiency and focus offset control effectiveness. An operating cycle is defined as a 30-minute data collection period during which the system operates continuously and stably. Photovoltaic output data includes the DC voltage (V), current (A), output power (W), and power fluctuation amplitude of the photovoltaic array output. Thermal output data includes the inlet and outlet temperatures, volume flow rate (L / min), and heat transfer efficiency (calculated as thermal power, in Watts) of the heat medium (such as water or thermal oil) flowing through the heat absorber. During data collection, measurement errors must be maintained within ±0.5% for voltage, ±0.3°C for temperature, and ±3 mL / min for flow rate. After data collection is completed, the total photovoltaic and thermal output for the current cycle is compared with the previous cycle. If the total energy decreases by more than 10%, the thermal and electrical output is out of sync, or the output power fluctuation increases significantly, it indicates that the thermal lensing effect may not be fully identified and suppressed during the current cycle, and the discriminant model needs to be updated.

[0052] The current operating data is cross-analyzed with the thermal lens identification indicators from the previous cycle to identify the dominant thermal lens sensitivity factor and adjust its discrimination threshold based on the actual measured values. These sensitivity factors include five: beam focus drift rate (in mm / min), spot area change rate (in square mm / min), film thermal stress growth rate (in MPa / min), local refractive index gradient change (dimensionless), and receiving area temperature gradient amplitude (in °C / cm). For example, if the beam focus drift rate in the current cycle is detected to reach 0.42 mm / min in the X-axis direction, and the original discriminator threshold is set at 0.30 mm / min, and the overall system energy efficiency decreases by 13% under this drift state, the drift rate threshold should be increased to above 0.35 mm / min to improve the discriminator's response sensitivity. The thresholds of other sensitive factors should also be proportionally adjusted based on the actual energy loss caused by the drift, with a correction limit of no more than ±15% introduced to ensure convergence.

[0053] Based on the revised sensitivity factor threshold, the parameters within the focus shift discriminator were updated, enabling proactive intervention in thermal lens identification and spot correction during future operation cycles. The focus shift discriminator relies on a set of thresholds compared with real-time sensor data to determine the presence and severity of focus drift. The update included increasing the "spot area expansion rate" from the original setting of 1.2mm² / min to 1.4mm² / min; adjusting the "film stress growth threshold" from 8MPa / min to 9.2MPa / min; and adjusting the "hot spot area temperature gradient" warning value from 12°C / cm to 14°C / cm. After the update was completed, verification was performed by loading a simulation data sequence, simulating the dynamic process of focus shifting from the center to the edge. The discriminator was tested to see if it issued an adjustment signal before the shift reached the 70% threshold. If the optical axis correction and incident angle adjustment instructions were triggered in advance, the parameter update was effective.

[0054] The results of this parameter correction and discriminator update are encapsulated as the current running version, and its control effect in at least two subsequent complete operating cycles is monitored to verify whether it brings about improved system energy efficiency and response stability. Subsequent monitoring includes indicators such as the synchronization rate of light and thermal synergy output (convergence of output change curves), focus drift response time, energy flux density center of gravity return time after focus recovery, and energy loss reduction (in kilowatt-hours). If it is found that the optimized threshold setting significantly improves energy utilization efficiency (the improvement is not less than 8%), reduces the frequency of adjustment and does not cause misjudgment, it means that this dynamic update strategy is effective and will continue to be used as the basic parameter for subsequent operation. If it is found that the discrimination sensitivity is too high after adjustment, resulting in frequent system adjustments, or the misjudgment rate increases by more than 5%, the previous stable version will be restored according to the data rollback mechanism to avoid a negative feedback loop.

[0055] The purpose of this step is to use the photovoltaic and thermal energy output data generated by the coordinated closed-loop operation as the basis for evaluating the operating status of the system, and to build a dynamic thermal lens suppression strategy optimization mechanism based on measured performance feedback, so as to continuously improve the intelligent response capability, adaptive control capability and stable output capability of the solar spectrum frequency division cogeneration device during actual operation. Traditional solar thermal power coordinated systems usually rely on preset static parameters to determine whether the light spot is offset, such as a fixed focus drift threshold, film stress warning value, thermal gradient warning line, etc. However, in a complex operating environment, these static parameters are difficult to cover all scenarios, and are prone to misjudgment, missed judgment or adjustment hysteresis, thereby affecting the coordinated efficiency of photovoltaic and photothermal output, and even inducing thermal damage to components.

[0056] This step quantitatively analyzes the photovoltaic and thermal energy output data in each operating cycle to identify the main physical factors affecting the current energy efficiency fluctuations, and then adaptively adjusts the judgment threshold of the thermal lens sensitivity factor (such as focus drift rate, refractive index change amplitude, temperature gradient change value, etc.), and simultaneously updates the internal parameters of the focus offset discriminator. This process not only improves the accuracy of the system in identifying thermal lens anomalies, but also ensures the timeliness and pertinence of subsequent correction operations, avoiding the problem of continued spread of spot offset and further attenuation of system energy efficiency due to response lag. At the same time, by solidifying the parameter adjustment results into a new version and continuously tracking the operating results, the mechanism also establishes an evolutionary path for the thermal lens control strategy, enabling the system to have the ability to continuously learn and gradually optimize.

[0057] This step constitutes the core of the self-closed-loop feedback of the entire thermal lens suppression system and is the key link in realizing the full-chain control logic of "identification-response-optimization-feedback". It opens up the logical relationship between physical signals, energy efficiency evaluation and parameter updates, so that the thermal lens suppression strategy no longer relies on single physical modeling and offline configuration, but instead turns to an online optimization path based on real operating data. Ultimately, this mechanism can significantly improve the stable operation performance of the system under long-term, high-intensity and variable climate conditions, and is the technical foundation and core support for realizing truly intelligent solar thermal and photovoltaic coordinated control.

[0058] The solar spectrum frequency division cogeneration operation method proposed above can realize the full process, dynamic, closed-loop identification, response and optimization control of the focus drift problem caused by the thermal lens effect, significantly improving the optical stability and energy conversion efficiency of the spectrum divider under long-term high-energy focusing operation conditions. The present invention realizes the accurate prediction of the thermal lens formation mechanism by establishing the coupling relationship between the beam wavefront, temperature distribution and refractive index change; it also ensures the real-time identification and classification of the focus drift state by extracting the thermal sensitive factor and constructing the offset level discriminator; and then combines the spectral path reconstruction, incident angle adjustment and flexible optical axis calibration means to dynamically correct the beam offset and maintain the alignment accuracy of the photoelectric and photothermal paths; at the same time, the adjustment results are fed back to the thermal management operation, combined with cooling flow control, heat conduction path switching and surface coating adjustment to achieve the coordinated stability of the photothermal path; finally, under the closed-loop evaluation mechanism, the parameters are continuously adaptively updated to achieve the continuous optimization and self-evolution control of the thermal lens suppression strategy. The overall solution runs through the collaborative control path of the three-dimensional physical fields of heat, light, and force, forming a closed loop from source identification, path correction to terminal feedback, effectively ensuring the energy acquisition stability and output power consistency of photovoltaic units and thermal collectors in long-term operation, and overcoming the energy efficiency fluctuations, load imbalance and device damage caused by thermal lens out of control in existing technologies.

[0059] The present invention provides Figure 2The solar spectrum frequency division cogeneration system shown in FIG. 1 includes a coupled modeling and analysis module, an offset criterion extraction module, a focus offset discrimination module, a dynamic spectrum adjustment module, a collaborative closed-loop control module, and a strategy optimization and evaluation module. The coupled modeling and analysis module establishes a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. It collects real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions, and generates an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. The offset criterion extraction module identifies the thermal lens sensitivity factor that causes the spot offset based on the estimated atlas of the refractive index gradient distribution, extracts the corresponding spot offset threshold, film stress threshold, and focus tolerance, and uses this to establish physical constraints for determining the beam offset state; The focus shift discrimination module builds a focus shift discriminator based on physical constraints, inverts the real-time focus coordinates based on the beam wavefront information, calculates the corresponding energy flux density, and classifies the degree of spot shift into a grade label; The dynamic spectrum adjustment module dynamically adjusts the spectrum splitting path according to the spot offset level label, realizes spectrum reconstruction by adjusting the incident angle and bandpass width, and drives the flexible micro-actuator to perform optical axis correction operation, so that the reconstructed light beam is stably projected to the predetermined energy receiving area; The collaborative closed-loop control module feeds back the operating status of the optical axis correction and spectral splitting adjustment to the thermal management system. Based on the heat distribution in the energy receiving area, it applies liquid cooling flow pulses and switches the phase change heat conduction channel. It also adjusts the absorptivity of the crossover surface coating to achieve a collaborative closed-loop operation of optical path adjustment and thermal management control. The strategy optimization and evaluation module evaluates the overall operation effect of the system based on the energy output data of collaborative closed-loop operation, adaptively corrects the threshold of the thermal lens sensitivity factor based on the evaluation results, and updates the parameters of the focus shift discriminator to achieve dynamic optimization of the thermal lens suppression strategy.

[0060] A solar spectrum frequency division cogeneration operation method provided in an embodiment of the present invention is realized by the above-mentioned solar spectrum frequency division cogeneration system. The specific method and process of a solar spectrum frequency division cogeneration system are detailed in the embodiment of the above-mentioned solar spectrum frequency division cogeneration operation method, which will not be repeated here.

[0061] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A solar spectrum frequency division cogeneration method, characterized in that: The following steps are involved: S001: Establish a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. Collect real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions. Generate an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. S002: Based on the estimated atlas of the refractive index gradient distribution, identify the thermal lens sensitivity factor that causes the spot offset, extract the corresponding spot offset threshold, film stress threshold, and focus tolerance, and use this to establish physical constraints for determining the beam offset state; S003, constructing a focus shift discriminator based on physical constraints, inverting the real-time focus coordinates based on the beam wavefront information, calculating the corresponding energy flux density, and classifying the degree of spot shift into a grade label; S004, dynamically adjusting the spectral splitting path according to the spot offset level label, achieving spectral reconstruction by adjusting the incident angle and bandpass width, and simultaneously driving the flexible microactuator to perform an optical axis correction operation so that the reconstructed light beam is stably projected to the predetermined energy receiving area; S005: Feedback the operating status after optical axis correction and spectral splitting adjustment to the thermal management system. Based on the heat distribution in the energy receiving area, liquid cooling flow pulses are applied and the phase change heat conduction channel is switched. At the same time, the absorptivity of the crossover surface coating is adjusted to achieve a coordinated closed-loop operation of optical path adjustment and thermal management control. S006, based on the energy output data of the collaborative closed-loop operation, evaluate the overall operation effect of the system, adaptively correct the threshold of the thermal lens sensitivity factor according to the evaluation results, and update the parameters of the focus shift discriminator to achieve dynamic optimization of the thermal lens suppression strategy.

2. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S001 includes: A simulated sunlight irradiation environment with a wavelength output capability of 300nm to 2500nm was constructed, and the output beam was focused using a combination of a quartz collimating lens and a parabolic reflector, projecting the beam onto the surface of a multilayer film spectrum divider sample; Under high-energy irradiation conditions, thermistors and infrared thermometers were used to collect real-time temperature data from the center, edge, and film interlayer of the spectrum divider surface, and the data were transmitted to the host platform at a frequency of 1 Hz. Synchronously collect the wavefront information formed by the light beam after passing through the spectrum divider, use the microlens array wavefront detection device to record the phase distortion of the outgoing light, and form a time-synchronized data pair with the corresponding temperature data; According to the thermally induced refractive index variation coefficient of each film material of the frequency divider, the refractive index variation value at each spatial position is calculated in combination with the temperature measurement data, and the three-dimensional refractive index gradient distribution map is reconstructed. The gradient greater than 0.05 is marked by color mapping. The area is a high-risk area for thermal lensing, so as to form an optical prediction map for subsequent offset judgment.

3. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S002 includes: Based on the obtained refractive index gradient distribution map, the refractive index change value greater than Each millimeter of heat-sensitive area is regarded as a high-risk area, and the temperature sampling data of the corresponding area is extracted for heat accumulation feature analysis; In the high-risk area mentioned above, the equivalent internal stress change caused by temperature rise was measured in combination with the film structure of the spectrum divider, and the film stress threshold correlated with the spot offset height was extracted. The film stress threshold was set to 65MPa. By measuring the energy distribution of the light spot at different offset positions, it was determined that an offset exceeding 0.6mm would result in a significant decrease in energy reception. Based on this, the focus tolerance was set to within 0.6mm. Based on the spot offset threshold, film stress threshold and focusing tolerance, physical constraints are established to determine the beam offset state. When any position meets the above three physical conditions at the same time, it is determined that focus drift induced by thermal lensing occurs at that position.

4. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S003 includes: Based on the established physical constraints on spot deviation, a microlens array wavefront sensor was placed on the main axis of the spectral divider's outgoing direction. The sensor collected a two-dimensional wavefront phase diagram of the outgoing beam under sunlight and monitored the optical axis deviation at a frequency of 20 frames per second. When the principal optical axis represented by the wavefront data deviates by more than 0.2 mm in the X or Y direction, the coordinates of the focus in the X, Y, and Z directions in three-dimensional space are calculated based on the relationship between the phase contour density in the wavefront image and the optical path tracing, and the spatial offset distance of the focus relative to the reference position is obtained; A receiving device composed of a high-stability liquid crystal temperature-sensitive film is set at the focal position, and a two-dimensional thermal map of the focal hot zone is measured with an infrared thermal imager. The focal energy flux density distribution is obtained through grayscale inversion, and the degree of focal energy concentration is evaluated. The focal spatial offset distance and the concentration of energy flux density are used as joint criteria. According to the extracted spot offset threshold, film stress threshold and focusing tolerance, the current spot offset state is divided into five levels, marked as level one to level five, which serve as the basis for the subsequent dynamic adjustment of the spectral path and correction of the incident angle.

5. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S004 includes: Based on the determined spot offset level label, determine whether to trigger the spectral path adjustment operation. If the offset level is level 1, no adjustment is performed. If it is level 2, the incident angle fine-tuning operation is performed. If it is level 3 or above, the incident angle adjustment, bandpass width adjustment and optical axis correction operations are performed simultaneously. The tiltable reflector assembly driven by piezoelectric ceramics is used to adjust the inclination of the reflector in the X and Y directions, controlling the reflection angle within the range of ±3°, changing the main incident angle of the light beam entering the spectrum splitter, and realigning the split light beam to the target energy receiving area. The thickness of the interference filter layer is adjusted using a piezoelectric micro-drive, and the bandpass center wavelength is adjusted within the range of ±50nm, controlling the bandwidth to be compressed to 25nm or 20nm, thereby improving the concentration of spectral energy and reception efficiency. The piezoelectric ceramic drive unit on the flexible hinge platform is used to perform micro-displacement corrections on the optical axis in the X-axis and Y-axis directions, so that the light beam remains perpendicular to the target receiving surface. Ultimately, the landing point offset of the corrected light beam is controlled within ±0.2mm, ensuring stable energy transmission to the photovoltaic or solar thermal unit.

6. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S005 includes: After completing the optical axis correction and spectral splitting path adjustment operations, based on the heat redistribution on the receiving surface, a thermocouple array and infrared thermal imaging equipment arranged on the back of the photovoltaic module and behind the heat absorption surface are used to collect a two-dimensional temperature distribution map of the hot surface, and determine whether there is a heat concentration state with a central temperature higher than 50°C and a peripheral temperature lower than 30°C; When the heat concentration state is determined to be established, the liquid cooling plate structure is controlled to apply an instantaneous strong cooling flow pulse, instantly increasing the flow rate from 300mL / min to 450mL / min. The pulse duration is 5 seconds to quickly diffuse the local heat and reduce the temperature rise in the central overheating area. After the liquid cooling pulse operation is completed, the heat conduction paths of the paraffin and indium tin phase change heat conduction structures are switched according to the temperature differences in different areas of the hot surface. When the hot surface temperature is between 45°C and 55°C, the paraffin heat conduction path is activated, and when the temperature is close to 80°C, the indium tin heat conduction path is activated, achieving balanced conduction and release of deep heat. Based on the focus shift level and thermal distribution characteristics, the absorption performance of the multi-layer absorption film composed of chromium oxide black and silicon nitride deposited on the surface of the spectral divider is adjusted, and the surface temperature is fine-tuned to within ±5°C through a graphite heater, thereby achieving an absorption rate increase of no more than 2% in the mid- and far-infrared bands, thereby enhancing energy absorption stability and synergistically alleviating photothermal fluctuations under high shift levels.

7. The solar spectrum frequency division cogeneration operation method according to claim 1, characterized in that: Step S006 includes: After completing the optical axis correction and thermal management closed-loop operation, collect the DC voltage, current, output power and power fluctuation amplitude of the photovoltaic array, as well as the inlet temperature, outlet temperature, volume flow rate and heat transfer efficiency data of the heat medium at the heat absorption end during the current complete operation cycle, and determine whether there is a total energy drop of more than 10% compared with the previous cycle, coordinated output is out of sync, or power fluctuation is aggravated; If an abnormality is detected, the threshold of each sensitive factor is adjusted proportionally by no more than ±15% based on the five sensitive factors of the current cycle: beam focus offset speed, spot area change rate, film thermal stress growth rate, local refractive index gradient change, and receiving area temperature gradient amplitude, combined with the energy loss ratio. The revised sensitivity factor thresholds were used to update the focus shift discriminator parameter set, including adjusting the spot area expansion rate to 1.4 mm² / min, the film stress growth threshold to 9.2 MPa / min, and the hot spot temperature gradient warning value to 14°C / cm. Simulation sequences were used to verify whether the new parameters could trigger correction instructions before the shift reached the 70% threshold. The updated parameters are encapsulated as the current running version, and the changes in the photothermal output synchronization rate, focus drift response time, focus return speed, and energy loss are monitored in the next two operating cycles. If the energy efficiency improvement is no less than 8% and the misjudgment rate does not exceed 5%, the parameter update is confirmed to be valid and will continue to be used in subsequent control strategies.

8. A solar spectrum frequency division cogeneration system, used to implement the solar spectrum frequency division cogeneration operation method according to any one of claims 1 to 7, characterized in that: It includes coupling modeling and analysis module, offset criterion extraction module, focus offset discrimination module, dynamic spectrum adjustment module, collaborative closed-loop control module and strategy optimization and evaluation module: The coupled modeling and analysis module establishes a coupled analysis baseline between irradiation parameters, heat distribution, and optical properties. It collects real-time temperature data and beam wavefront information of the spectrum splitter under solar illumination conditions, and generates an estimated map of the refractive index gradient distribution based on the law of thermally induced refractive index changes. The offset criterion extraction module identifies the thermal lens sensitivity factor that causes the spot offset based on the estimated atlas of the refractive index gradient distribution, extracts the corresponding spot offset threshold, film stress threshold, and focus tolerance, and uses this to establish physical constraints for determining the beam offset state; The focus shift discrimination module builds a focus shift discriminator based on physical constraints, inverts the real-time focus coordinates based on the beam wavefront information, calculates the corresponding energy flux density, and classifies the degree of spot shift into a grade label; The dynamic spectrum adjustment module dynamically adjusts the spectrum splitting path according to the spot offset level label, realizes spectrum reconstruction by adjusting the incident angle and bandpass width, and drives the flexible micro-actuator to perform optical axis correction operation, so that the reconstructed light beam is stably projected to the predetermined energy receiving area; The collaborative closed-loop control module feeds back the operating status of the optical axis correction and spectral splitting adjustment to the thermal management system. Based on the heat distribution in the energy receiving area, it applies liquid cooling flow pulses and switches the phase change heat conduction channel. It also adjusts the absorptivity of the crossover surface coating to achieve a collaborative closed-loop operation of optical path adjustment and thermal management control. The strategy optimization and evaluation module evaluates the overall operation effect of the system based on the energy output data of collaborative closed-loop operation, adaptively corrects the threshold of the thermal lens sensitivity factor based on the evaluation results, and updates the parameters of the focus shift discriminator to achieve dynamic optimization of the thermal lens suppression strategy.

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