Device and method for monitoring expansion of heat collecting tube of linear Fresnel type photo-thermal power station

Abstract

The invention discloses a photo-thermal power station heat collecting tube expansion monitoring system which comprises a heat collecting tube, an arc-shaped secondary reflector is connected to the outer wall of the heat collecting tube through a steel rod, the secondary reflector is arranged around the side wall of the heat collecting tube and connected with the bottom of a cantilever through a steel rod, supporting rods are vertically connected to the two ends of the cantilever respectively, displacement sensors are installed on the supporting rods, and the displacement sensors are connected with the displacement sensors. The displacement sensor is arranged close to the port of the heat collecting pipe; the heat collecting pipe is provided with a temperature sensor and an electromagnetic sensor; the center of the heat collecting pipe is sleeved with a fixing ring, and the temperature sensor, the displacement sensor and the electromagnetic sensor are all electrically connected with a controller. A photo-thermal power station heat collecting tube expansion monitoring method comprises the steps that data are obtained, and an alarm program is set in a chip; establishing a simulation model to calculate a theoretical expansion value, comparing the data with the theoretical expansion value, displaying the data on a display screen, and triggering an alarm by an abnormal expansion value; the problem that in the prior art, the power generation efficiency is reduced due to the fact that the expansion condition of the heat collecting pipe cannot be monitored in real time and countermeasures cannot be taken in time is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of safety detection methods for photovoltaic power stations, and specifically relates to a device for monitoring the expansion of a collector tube of a linear Fresnel photovoltaic power station. The present invention also relates to a method for monitoring the expansion of a collector tube of a linear Fresnel photovoltaic power station. Background Art

[0002] As one of the main technical routes in the field of solar thermal power generation, linear Fresnel solar thermal power generation technology has been put into operation and is under construction in many power stations around the world. Among them, the vacuum collector tube in the concentrating solar collector system is the core equipment for photothermal conversion and utilization. A single vacuum collector tube is welded in series to form a collector branch with a length of 1200m. It is fixed in the middle and expands freely at both ends. Under the influence of light and the flow of high-temperature molten salt inside, it will produce uneven expansion at both ends. If the expansion encounters resistance, the deflection of the vacuum collector branch will increase, causing accidents such as rupture of the vacuum collector tube and leakage of molten salt, which will have an adverse effect on the normal collection and power generation of the power station.

[0003] The currently operating linear Fresnel CSP plants and the CSP plants under construction are unable to conduct online status monitoring and early warning for the expansion of the suspension structure of the vacuum collector tube collector branch. Summary of the invention

[0004] The purpose of the present invention is to provide a linear Fresnel type solar thermal power station collector tube expansion monitoring device, which solves the problem in the prior art that the collector tube expansion cannot be monitored in real time and timely countermeasures cannot be taken, resulting in reduced power generation efficiency.

[0005] Another object of the present invention is to provide the above-mentioned linear Fresnel type solar thermal power station collector tube expansion monitoring method, which solves the problem of potential safety hazards of the collector tube in the prior art.

[0006] The technical solution adopted by the present invention is a linear Fresnel type solar thermal power station collector tube expansion monitoring device, including a collector tube, an arc-shaped secondary reflector is connected to the outer wall of the collector tube through a steel rod, the secondary reflector is arranged around the side wall of the collector tube, the secondary reflector is connected to the bottom of the suspension beam through the steel rod, the two ends of the suspension beam are respectively vertically connected to support rods, displacement sensors are installed on the support rods, and the displacement sensors are arranged near the port of the collector tube; the collector tube is provided with a temperature sensor and an electromagnetic sensor; a fixing ring is sleeved at the center of the collector tube, and the temperature sensor, the displacement sensor and the electromagnetic sensor are all electrically connected to a controller.

[0007] The present invention is also characterized in that: A chip is arranged inside the controller, and the chip is electrically connected to the temperature sensor, the electromagnetic sensor and the displacement sensor respectively; a display screen and an alarm are arranged on the surface of the controller, and the chip is electrically connected to the display screen and the alarm respectively.

[0008] Another technical solution adopted by the present invention is a linear Fresnel type solar thermal power station collector tube expansion monitoring method, using a linear Fresnel type solar thermal power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtain the physical data of the heat collecting tube and the secondary reflector, the displacement data at both ends of the heat collecting tube and the environmental data of the heat collecting tube, and set an alarm program in the chip; Step 2: construct a simulation model of the heat collector expansion device in the chip based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm.

[0009] Another technical solution of the present invention is also characterized in that: Physical data include structural parameters, molten salt physical and chemical performance parameters; environmental data include temperature, flow rate, and solar radiation.

[0010] An artificial network algorithm is set in the simulation model, and the artificial network algorithm includes an input layer, a hidden layer and an output layer; a loss function is set in the hidden layer.

[0011] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the theoretical expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0012] The expansion threshold includes the expansion threshold of the input end and the expansion threshold of the output end. The calculation formula of the expansion threshold of the input end is: (3) In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output expansion threshold is: (4) In formula (4), represents the expansion threshold at the output, Represents the displacement of the output end of the collector tube.

[0013] The normal expansion value is that the displacement data is not greater than the theoretical expansion value and the absolute value of the difference between the displacement data and the theoretical expansion value is not greater than the expansion threshold; the abnormal expansion value is that the displacement data is greater than the theoretical expansion value or the absolute value of the difference between the displacement data and the theoretical expansion value is greater than the expansion threshold.

[0014] The beneficial effects of the present invention are as follows: the present invention is provided with a controller, which can monitor the expansion displacement of the heat collecting tube and the temperature and irradiation of the heat collecting tube in real time, construct a simulation model of the heat collecting tube expansion device of a linear Fresnel type solar thermal power station in the chip, calculate the collected expansion displacement of the heat collecting tube and the temperature and irradiation of the heat collecting tube, obtain the theoretical expansion value and the maximum expansion value, compare the expansion data with the theoretical expansion value and the maximum expansion value respectively, obtain the evaluation result, and timely alarm of abnormal situation and real-time display of expansion data can be realized through the analysis of the evaluation result. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the expansion monitoring device for the heat collecting tube of a linear Fresnel type solar thermal power station of the present invention; Figure 2 It is a nonlinear curve diagram in Example 6 of the present invention.

[0016] In the figure, 1. heat collecting tube, 2. secondary reflector, 3. cantilever beam, 4. support rod, 5. displacement sensor, 6. temperature sensor, 7. electromagnetic sensor, 8. fixing ring, 9. controller, 901. chip, 902. display screen, 903. alarm. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The linear Fresnel type solar thermal power station collector tube expansion monitoring device of the present invention is as follows Figure 1As shown, it includes a heat collecting tube 1, the outer wall of the heat collecting tube 1 is connected with an arc-shaped secondary reflector 2 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of the suspension beam 3 through the steel rod, the two ends of the suspension beam 3 are respectively vertically connected with support rods 4, and a displacement sensor 5 is installed on the support rod 4. The displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0019] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0020] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0021] Physical data include structural parameters, molten salt physical and chemical performance parameters; environmental data include temperature, flow rate, and solar radiation.

[0022] An artificial network algorithm is arranged in the simulation model, and the artificial network algorithm comprises an input layer, a hidden layer and an output layer; a loss function is arranged in the hidden layer.

[0023] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the theoretical expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0024] The expansion threshold includes the expansion threshold of the input end and the expansion threshold of the output end. The calculation formula of the expansion threshold of the input end is: (3) In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output expansion threshold is: (4) In formula (4), represents the expansion threshold at the output, Represents the displacement of the output end of the collector tube.

[0025] The normal expansion value is that the displacement data is not greater than the theoretical expansion value and the absolute value of the difference between the displacement data and the theoretical expansion value is not greater than the expansion threshold; the abnormal expansion value is that the displacement data is greater than the theoretical expansion value or the absolute value of the difference between the displacement data and the theoretical expansion value is greater than the expansion threshold.

[0026] When the linear Fresnel type CSP collector tube expansion monitoring device is in operation, the displacement sensor 5 collects the axial expansion displacement at both ends of the collector tube 1. The expansion displacement at the input end of the collector tube 1 is , the expansion displacement at the output end of the collector tube 1 is .

[0027] The simulation model of the expansion device of the collector tube of a linear Fresnel solar thermal power station is edited by Python language. The input temperature, flow rate, solar radiation and expansion displacement are input into the simulation model. The theoretical expansion values ​​of the input and output ends of the collector tube 1 are calculated. If the expansion displacement is not greater than the theoretical expansion value and the expansion displacement is not greater than the absolute value of the difference between the expansion displacement and the theoretical expansion value, the expansion displacement is a normal expansion value; if the expansion displacement is greater than the theoretical expansion value or the expansion displacement is greater than the absolute value of the difference between the expansion displacement and the theoretical expansion value, the expansion displacement is an abnormal expansion value. The abnormal expansion value and the normal expansion value are simultaneously transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program in the chip 901, and the alarm 903 sounds an alarm.

[0028] Example 1 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0029] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0030] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0031] The simulation model contains an artificial neural network algorithm, which includes an input layer, a hidden layer, and an output layer. After repeated experiments, the number of neurons is determined to be 5; the weight of the input hidden layer =6, implicit threshold 5, the weight of the hidden output layer 5, output threshold is 1, the number of artificial neural network training iterations is T=100, and the learning rate .

[0032] The collected temperature, flow and irradiance data of a certain solar collector circuit and the actual monitoring values ​​at the same time are used as training data samples to train the artificial neural network algorithm. The goal is to minimize the deviation between the output value and the actual displacement data, determine the optimal initial weights and thresholds of the artificial neural network, and complete the model construction.

[0033] The model is used to simulate the theoretical expansion of the collector branch. After a period of data sample accumulation, a comprehensive analysis is performed with the actual displacement data to determine the expansion deviation thresholds at the inlet and outlet ends. The inlet operating temperature range is generally 20°C, and the outlet operating temperature range is 20°C.

[0034] Example 2 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0035] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0036] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0037] The model is used to simulate the theoretical expansion of the collector branch. After a period of data sample accumulation, a comprehensive analysis is performed with the actual displacement data to determine the expansion deviation thresholds at the inlet and outlet ends. The inlet operating temperature range is generally 450°C, and the outlet operating temperature range is 550°C.

[0038] Physical data include structural parameters, molten salt physical and chemical performance parameters; environmental data include temperature, flow rate, and solar radiation.

[0039] An artificial network algorithm is arranged in the simulation model, and the artificial network algorithm comprises an input layer, a hidden layer and an output layer; a loss function is arranged in the hidden layer.

[0040] Example 3 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0041] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0042] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0043] The simulation model uses a black box model of big data. The model uses neural network and other algorithms to solve the model. After a period of data sample accumulation, it is comprehensively analyzed with the actual displacement data to determine the expansion deviation thresholds of the inlet and outlet ends. , different values ​​can be determined according to the molten salt operating temperature zone: [260, 360], [360, 460] or [460, 560].

[0044] The model is used to simulate the theoretical expansion of the collector branch. After a period of data sample accumulation, a comprehensive analysis is performed with the actual displacement data to determine the expansion deviation thresholds at the inlet and outlet ends. The inlet operating temperature range is generally 350℃, and the outlet operating temperature range is 250℃.

[0045] Physical data include structural parameters, molten salt physical and chemical performance parameters; environmental data include temperature, flow rate, and solar radiation.

[0046] An artificial network algorithm is arranged in the simulation model, and the artificial network algorithm comprises an input layer, a hidden layer and an output layer; a loss function is arranged in the hidden layer.

[0047] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0048] Example 4 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0049] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0050] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0051] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0052] The expansion threshold includes the expansion threshold of the input end and the expansion threshold of the output end. The calculation formula of the expansion threshold of the input end is: (3) In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output expansion threshold is: (4) Example 5 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0053] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0054] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0055] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the theoretical expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0056] The expansion threshold includes the expansion threshold of the input end and the expansion threshold of the output end. The calculation formula of the expansion threshold of the input end is: (3) In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output expansion threshold is: (4) The model is used to simulate the theoretical expansion of the collector branch. After a period of data sample accumulation, a comprehensive analysis is performed with the actual displacement data to determine the expansion deviation thresholds at the inlet and outlet ends. The inlet operating temperature range is generally 430℃, and the outlet operating temperature range is 450℃.

[0057] When the material of the heat collecting tube 1 is stainless steel, the thermal expansion coefficient at 20°C to 425°C is specifically shown in Table 1: Table 1 Thermal expansion coefficient of stainless steel

[0058] The fitted theoretical expansion rate formula is: ( ).

[0059] Example 6 The linear Fresnel type solar thermal power station heat collecting tube expansion monitoring device of the present invention comprises a heat collecting tube 1, an arc-shaped secondary reflector 2 is connected to the outer wall of the heat collecting tube 1 through a steel rod, the secondary reflector 2 is arranged around the side wall of the heat collecting tube 1, the secondary reflector 2 is connected to the bottom of a suspension beam 3 through a steel rod, both ends of the suspension beam 3 are vertically connected to support rods 4, a displacement sensor 5 is installed on the support rod 4, and the displacement sensor 5 is arranged near the port of the heat collecting tube 1; the heat collecting tube 1 is provided with a temperature sensor 6 and an electromagnetic sensor 7; a fixing ring 8 is sleeved at the center of the heat collecting tube 1, and the temperature sensor 6, the displacement sensor 5 and the electromagnetic sensor 7 are all electrically connected to a controller 9.

[0060] A chip 901 is provided inside the controller 9, and the chip 901 is electrically connected to the temperature sensor 6, the electromagnetic sensor 7 and the displacement sensor 5 respectively; a display screen 902 and an alarm 903 are provided on the surface of the controller 9, and the chip 901 is electrically connected to the display screen 902 and the alarm 903 respectively.

[0061] The linear Fresnel type CSP power station collector tube expansion monitoring method of the present invention uses a linear Fresnel type CSP power station collector tube expansion monitoring device, and the specific operating steps are as follows: Step 1, respectively obtaining the physical data of the heat collecting tube 1 and the secondary reflector 2, the displacement data at both ends of the heat collecting tube 1 and the environmental data of the heat collecting tube 1, and setting an alarm program in the chip 901; Step 2: construct a simulation model of the heat collecting tube expansion device in the chip 901 based on the physical data; Step 3: Input the environmental data into the simulation model to obtain the theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen 902 for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm device 903.

[0062] The calculation formula of theoretical expansion value is: (1) In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the expansion rate; (2) In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature, and obtaining a nonlinear curve such as Figure 2 As shown; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

[0063] The expansion threshold includes the expansion threshold of the input end and the expansion threshold of the output end. The calculation formula of the expansion threshold of the input end is: (3) In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output expansion threshold is: (4) The normal expansion value is that the displacement data is not greater than the theoretical expansion value and the absolute value of the difference between the displacement data and the theoretical expansion value is not greater than the expansion threshold; the abnormal expansion value is that the displacement data is greater than the theoretical expansion value or the absolute value of the difference between the displacement data and the theoretical expansion value is greater than the expansion threshold.

Claims

1. A linear Fresnel type solar thermal power station collector tube expansion monitoring device, characterized in that: The invention comprises a heat collecting tube (1), wherein an arc-shaped secondary reflector (2) is connected to the outer wall of the heat collecting tube (1) through a steel rod, the secondary reflector (2) is arranged around the side wall of the heat collecting tube (1), the secondary reflector (2) is connected to the bottom of a suspension beam (3) through a steel rod, the two ends of the suspension beam (3) are respectively vertically connected to support rods (4), a displacement sensor (5) is installed on the support rod (4), and the displacement sensor (5) is arranged near the end of the heat collecting tube (1); the heat collecting tube (1) is provided with a temperature sensor (6) and an electromagnetic sensor (7); a fixing ring (8) is sleeved at the center of the heat collecting tube (1), and the temperature sensor (6), the displacement sensor (5) and the electromagnetic sensor (7) are all electrically connected to a controller (9).

2. The linear Fresnel type solar thermal power station collector expansion monitoring device according to claim 1, characterized in that: The controller (9) is provided with a chip (901) therein, and the chip (901) is electrically connected to the temperature sensor (6), the electromagnetic sensor (7) and the displacement sensor (5) respectively; the surface of the controller (9) is provided with a display screen (902) and an alarm (903), and the chip (901) is electrically connected to the display screen (902) and the alarm (903) respectively.

3. A method for monitoring the expansion of a collector tube in a linear Fresnel CSP power station, characterized in that: Using the linear Fresnel type solar thermal power station collector expansion monitoring device described in claim 2, the specific operating steps are as follows: Step 1, respectively obtaining physical data of the heat collecting tube (1) and the secondary reflector (2), displacement data at both ends of the heat collecting tube (1) and environmental data of the heat collecting tube (1), and setting an alarm program in the chip (901); Step 2: constructing a simulation model of a heat collecting tube expansion device in the chip (901) based on the physical data; Step 3: inputting the environmental data into a simulation model to obtain a theoretical expansion value; Step 4: Calculate the expansion threshold value according to the displacement data, and compare the displacement data with the theoretical expansion value and the expansion threshold value respectively to obtain a normal expansion value and an abnormal expansion value; Step 5: The normal expansion value and the abnormal expansion value are transmitted to the display screen (902) for display, and the abnormal expansion value triggers the alarm program to issue an alarm through the alarm (903).

4. The method for monitoring the expansion of a collector tube of a linear Fresnel CSP power station according to claim 3, characterized in that: The physical data include structural parameters, physical and chemical performance parameters of molten salt; the environmental data include temperature, flow rate, and solar radiation.

5. The monitoring method of the solar thermal power station collector expansion monitoring system according to claim 4, characterized in that: An artificial network algorithm is arranged in the simulation model, and the artificial network algorithm comprises an input layer, a hidden layer and an output layer; a loss function is arranged in the hidden layer.

6. The monitoring method of the expansion monitoring system of the solar thermal power station collector according to claim 5, characterized in that: The calculation formula of the theoretical expansion value is: （1） In formula (1), It indicates the theoretical expansion value of the input or output end of the collector tube / m. When i=1, it indicates the input end, and when i=2, it indicates the output end. Indicates the displacement length of the input or output end of the collector tube / m, represents the theoretical expansion rate ( ); （2） In formula (2), Indicates the temperature of the output or input end of the heat collector. When i=1, it indicates the input end, and when i=2, it indicates the output end. A indicates the first temperature coefficient, B indicates the second temperature coefficient, and C indicates the displacement reference coefficient. The process of confirming the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C is as follows: obtaining the displacement data of the heat collecting tube and the temperature corresponding to the displacement data, calculating the parameter expansion rate of the heat collecting tube at different temperatures, standardizing the parameter expansion rate to obtain the optimized expansion rate, performing binary nonlinear regression fitting on the optimized expansion rate and temperature to obtain a nonlinear curve; the coefficients of the nonlinear curve are the first temperature coefficient A, the second temperature coefficient B and the displacement reference coefficient C.

7. The monitoring method of the expansion monitoring system of the solar thermal power station collector tube according to claim 6, characterized in that: The expansion threshold includes an input expansion threshold and an output expansion threshold. The calculation formula of the input expansion threshold is: （3） In formula (3), represents the expansion threshold at the input, represents the displacement of the input end of the collector tube; The calculation formula of the output end expansion threshold is: （4） In formula (4), represents the expansion threshold at the output, Represents the displacement of the output end of the collector tube.

8. The monitoring method of the solar thermal power station collector expansion monitoring system according to claim 7, characterized in that: The normal expansion value is that the displacement data is not greater than the theoretical expansion value and the absolute value of the difference between the displacement data and the theoretical expansion value is not greater than the expansion threshold; the abnormal expansion value is that the displacement data is greater than the theoretical expansion value or the absolute value of the difference between the displacement data and the theoretical expansion value is greater than the expansion threshold.

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