A maintenance method for maintenance equipment of a trough type solar thermal power station heat collection circuit

Abstract

The present invention discloses a maintenance method for maintenance equipment of a heat collection circuit of a trough-type solar thermal power station, the maintenance equipment comprising: an oil tank and an antioxidant device. The oil tank is used to store heat transfer oil, and the antioxidant device is used to output antioxidant gas. The maintenance method comprises a circuit oil withdrawal step: closing both ends of the heat collection circuit, connecting the inlet of the oil tank to one end of the heat collection circuit, connecting the antioxidant device to the other end of the heat collection circuit, utilizing the internal pressure of the heat collection circuit and the antioxidant gas to purge, recovering the heat transfer oil in the heat collection circuit into the oil tank, and then performing maintenance operations on the heat collection circuit. The present invention can achieve rapid oil discharge of the heat collection circuit through the circuit oil withdrawal step, with high efficiency, and isolate the heat transfer oil from air throughout the operation to avoid oxidation of the heat transfer oil. After draining the oil, the entire process of heat collection circuit maintenance work can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of trough type solar thermal power plants, and in particular to a maintenance method for heat collection circuit maintenance equipment of a trough type solar thermal power plant. Background Art

[0002] The primary collector equipment in a parabolic trough solar power plant is the collector array. A typical 50MW parabolic trough plant is equipped with approximately 650 rows of collectors, each 150 meters long. Each collector circuit consists of four rows of collectors connected in series, for a total of approximately 150 collector circuits. Over the long term, collector circuits can experience problems such as blockages in the collector pipes, leaking rotary joints, and damaged collector pipes. To address these issues, the thermal oil in the collector circuit must be recovered. After repairs are complete, the circuit must undergo a tightness test and pass the test before oil filling and commissioning. Before oil filling, the collector circuit must be nitrogen-filled to isolate the air. During oil filling, the temperature difference between the collector pipe and the thermal oil must be kept within a certain range. After oil filling, the oil must be circulated and heated to a temperature close to that of the return oil main before it is incorporated into the collector circuit. Existing technologies suffer from low efficiency and poor safety. They lack anti-oxidation measures for the thermal oil, cannot perform tightness testing, cannot flexibly adjust the oil filling temperature difference, cannot measure heat loss in the collector circuit, and lack circuit dredging capabilities. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a maintenance method for the thermal collection circuit maintenance equipment of a trough-type solar thermal power station in response to at least one defect of the related technology mentioned in the above background technology: low efficiency in recovering the thermal oil in the thermal collection circuit.

[0004] The technical solution adopted by the present invention to solve the technical problem is to construct a maintenance method for the heat collecting circuit maintenance equipment of a trough type solar thermal power station.

[0005] Maintenance equipment includes:

[0006] An oil tank, wherein the oil tank is used to store thermal oil;

[0007] an anti-oxidation device, the anti-oxidation device being used to output anti-oxidation gas;

[0008] The maintenance method comprises the following steps:

[0009] Loop oil withdrawal steps: close both ends of the heat collection loop, connect the inlet of the oil tank to one end of the heat collection loop, connect the anti-oxidation device to the other end of the heat collection loop, use the internal pressure of the heat collection loop and the anti-oxidation gas to purge, recover the heat transfer oil in the heat collection loop into the oil tank, and then perform maintenance on the heat collection loop.

[0010] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0011] The maintenance equipment also includes:

[0012] a first pressure measuring element, the first pressure measuring element being provided on the tightness test loop and being used to measure the loop pressure;

[0013] The maintenance method further comprises:

[0014] Tightness test steps: After the heat collection circuit is overhauled, the anti-oxidation device is connected to the heat collection circuit to form a tightness test circuit, and the tightness of the heat collection circuit is tested according to the pressure value of the first pressure measuring element.

[0015] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0016] The maintenance equipment also includes:

[0017] A circulating pump, which is provided at the outlet end of the oil tank and is used for circulating the heat transfer oil;

[0018] The maintenance method further comprises:

[0019] Loop oil filling step: After the tightness test of the heat collection loop is passed, the inlet of the oil tank is connected to one end of the heat collection loop, and the outlet of the circulation pump is connected to the other end of the heat collection loop to form an oil filling loop, and the circulation pump is started to fill the heat collection loop with oil.

[0020] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0021] The maintenance equipment also includes:

[0022] A circulating pump, which is provided at the outlet end of the oil tank and is used to transport the thermal oil;

[0023] A heater is provided in the oil tank and is used to heat the thermal oil;

[0024] a second temperature measuring element, the second temperature measuring element being provided on the heat loss measurement circuit and being used to measure the temperature of the heat transfer oil in the circuit;

[0025] The maintenance method further comprises:

[0026] Heat dissipation loss measurement steps: After the heat collection circuit is filled with oil, the inlet of the oil tank is connected to one end of the heat collection circuit, and the outlet of the circulation pump is connected to the other end of the heat collection circuit to form a heat dissipation loss measurement circuit. The circulation pump is kept running, and the heater is turned on to heat the heat transfer oil in the heat collection circuit. The preset time is continuously collected through the second temperature measuring element, and the heat dissipation loss is evaluated according to the temperature drop value of the heat transfer oil.

[0027] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0028] The maintenance equipment also includes:

[0029] A dredging pump, which is provided at the outlet end of the oil tank and is used to transport thermal oil for dredging;

[0030] a first oil drain tank, the first oil drain tank being used to connect to one end of the heat collection circuit;

[0031] a second oil drain tank, the second oil drain tank being used to connect to the other end of the heat collection loop;

[0032] The maintenance method further comprises:

[0033] Full circuit dredging step: after the oil in the circuit is drained, the outlet of the dredging pump is connected to one end of the heat collection circuit, and the inlet of the oil tank is connected to the other end of the heat collection circuit to form a dredging circuit, and the dredging pump is started to dredge the heat collection circuit;

[0034] Alternatively, the segmented circuit unclogging step: after the oil is drained from the circuit, one end of the heat collection circuit is connected to the first oil drain barrel, the other end of the heat collection circuit is connected to the second oil drain barrel, the outlet of the unclogging pump is connected to the segmentation point of the heat collection circuit, and the unclogging pump is started to unblock the segments on the heat collection circuit.

[0035] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0036] One end of the heat collection loop is provided with a first switch valve and a first oil drain valve, and the other end of the heat collection loop is provided with a second switch valve and a second oil drain valve; the lowest point of the heat collection loop is provided with a third oil drain valve;

[0037] The anti-oxidation device comprises: at least one gas tank, a gas outlet valve provided at the outlet end of the gas tank, and a second pressure measuring element provided at the outlet end of the gas outlet valve;

[0038] The maintenance equipment also includes:

[0039] an oil level measuring element, the oil level measuring element being disposed in the oil tank and being used to measure the oil level in the oil tank;

[0040] an oil drain pipe, the oil drain pipe being used to connect the first oil drain valve and the inlet of the oil tank;

[0041] a gas pipeline, the gas pipeline being used to connect the second oil discharge valve and the gas outlet valve;

[0042] The circuit oil withdrawal step includes:

[0043] S11: closing the first on-off valve and the second on-off valve;

[0044] S12: connecting the first oil drain valve and the inlet of the oil tank through the oil drain pipe, and connecting the second oil drain valve and the gas outlet valve through the gas pipe;

[0045] S13: slowly opening the first oil drain valve to recover the thermal oil to the oil tank using the internal pressure of the heat collection circuit;

[0046] S14: When the oil level in the oil tank stops rising after being checked by the oil level measuring element, slowly opening the gas outlet valve, checking the second pressure measuring element, and maintaining the pressure of the pipeline from the gas tank to the second oil drain valve at a first preset pressure value;

[0047] S15: slowly opening the second oil drain valve and using anti-oxygen gas to purge the remaining thermal oil in the heat collection circuit into the oil tank;

[0048] S16: When the oil level in the oil tank stops rising by checking through the oil level measuring element and the third oil drain valve is opened to check that no thermal oil flows out, it is confirmed that all the thermal oil in the heat collection circuit has been drained, the gas outlet valve is closed, the oil drain pipe and the gas pipe are disassembled, and the heat collection circuit is inspected and maintained.

[0049] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0050] One end of the heat collection loop is provided with a first switch valve and a first oil drain valve, and the other end of the heat collection loop is provided with a second switch valve and a second oil drain valve; the lowest point of the heat collection loop is provided with a third oil drain valve;

[0051] The anti-oxidation device comprises: at least one gas tank, a gas outlet valve provided at the outlet end of the gas tank, and a second pressure measuring element provided between the outlet of the gas tank and the gas outlet valve;

[0052] The maintenance equipment also includes:

[0053] a gas pipeline, the gas pipeline being used to connect the second oil discharge valve and the gas outlet valve;

[0054] The tightness test steps include:

[0055] S21: After the heat collection circuit maintenance is completed and the status of each valve is confirmed to be normal, check whether the first on-off valve, the second on-off valve, the first oil drain valve and the second oil drain valve are in the closed state;

[0056] S22: Connect the second oil drain valve and the gas outlet valve via the gas pipeline to form a tightness test loop;

[0057] S23: Open the gas outlet valve, slowly open the second oil drain valve, and when the pressure of the heat collection circuit is checked by the first pressure measuring element to be a second preset pressure value, close the gas outlet valve;

[0058] S24: when the pressure value of the first pressure measuring element stops decreasing, opening the gas outlet valve, continuing to slowly open the second oil drain valve, and when the pressure of the heat collection circuit is detected by the first pressure measuring element to be a third preset pressure value, closing the gas outlet valve; wherein the third preset pressure value is greater than the second preset pressure value;

[0059] S25: when the pressure value of the first pressure measuring element stops decreasing, opening the gas outlet valve, continuing to slowly open the second oil drain valve, and when the pressure of the heat collection circuit is detected by the first pressure measuring element to be a fourth preset pressure value, closing the gas outlet valve; wherein the fourth preset pressure value is greater than the third preset pressure value;

[0060] S26: When the pressure value of the first pressure measuring element does not drop, the test is passed.

[0061] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0062] One end of the heat collection loop is provided with a first switch valve and a first oil drain valve, and the other end of the heat collection loop is provided with a second switch valve and a second oil drain valve; the lowest point of the heat collection loop is provided with a third oil drain valve;

[0063] The maintenance equipment also includes:

[0064] an oil level measuring element, the oil level measuring element being disposed in the oil tank and being used to measure the oil level in the oil tank;

[0065] an oil filling pipe, the oil filling pipe being used to connect the outlet of the circulation pump and the second oil drain valve;

[0066] an oil return pipe, the oil return pipe being used to connect the inlet of the oil tank and the first oil drain valve;

[0067] a first flow measuring element, the first flow measuring element being provided on the oil injection circuit and being used to measure the flow rate of the thermal oil in the circuit;

[0068] The circuit oil filling step comprises:

[0069] S31: After the tightness test of the heat collection circuit is passed, check whether the first on-off valve, the second on-off valve, the first oil drain valve, the second oil drain valve, and the third oil drain valve are in a closed state;

[0070] S32: connecting the outlet of the circulation pump and the second oil drain valve through the oil filling pipe, and connecting the inlet of the oil tank and the first oil drain valve through the oil return pipe to form an oil filling circuit;

[0071] S33: Open the first oil drain valve and the second oil drain valve, and start the circulation pump to fill oil into the heat collection circuit;

[0072] S34: After checking that the oil in the heat collection circuit is continuously flowing through the first flow measuring element and that the oil level in the oil tank is stable through the oil level measuring element, the circulation pump is stopped, and the first and second oil drain valves are closed, and the oil filling is completed.

[0073] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0074] One end of the heat collection circuit is provided with a first switch valve and a first oil drain valve, and the other end of the heat collection circuit is provided with a second switch valve and a second oil drain valve;

[0075] The maintenance equipment also includes:

[0076] a first temperature measuring element, the first temperature measuring element being disposed in the oil tank and being used to measure the temperature of the thermal oil in the oil tank;

[0077] a first flow measuring element, the first flow measuring element being provided on the heat loss measurement circuit and being used to measure the flow of the thermal oil in the circuit;

[0078] a second temperature measuring element, the second temperature measuring element being provided on the heat loss measurement circuit and being used to measure the temperature of the heat transfer oil in the circuit;

[0079] an oil filling pipe, the oil filling pipe being used to connect the outlet of the circulation pump and the second oil drain valve;

[0080] an oil return pipe, the oil return pipe being used to connect the inlet of the oil tank and the first oil drain valve;

[0081] The heat loss measurement step comprises:

[0082] S41: After the heat collection circuit is filled with oil, the oil filling pipe is connected to the outlet of the circulation pump and the second oil drain valve, and the oil return pipe is connected to the inlet of the oil tank and the first oil drain valve, forming a heat loss measurement circuit. The circulation pump is kept running, the first oil drain valve and the second oil drain valve are opened, and the first on-off valve and the second on-off valve are closed. The heater is started to heat the heat transfer oil in the heat collection circuit.

[0083] S42: When the temperature of the heat transfer oil in the heat collection circuit is detected by the first temperature measuring element to rise to a preset temperature value, the heater is stopped, the circulation pump is kept running, and the flow rate of the heat transfer oil in the heat collection circuit is controlled to a preset flow rate value by the first flow measuring element;

[0084] S43: Continuously collecting data from the heat collection circuit for a preset time through the second temperature measuring element, and evaluating the heat dissipation loss according to the temperature drop value of the thermal oil.

[0085] Preferably, in the maintenance method of the parabolic trough solar thermal power station collector circuit maintenance equipment of the present invention,

[0086] One end of the heat collection loop is provided with a first switch valve and a first oil drain valve, and the other end of the heat collection loop is provided with a second switch valve and a second oil drain valve; the lowest point of the heat collection loop is provided with a third oil drain valve;

[0087] The maintenance equipment also includes:

[0088] an oil filling pipe, the oil filling pipe being used to connect the outlet of the dredging pump and the second oil drain valve or the third oil drain valve;

[0089] an oil return pipe, the oil return pipe being used to connect the inlet of the oil tank and the first oil drain valve;

[0090] a first flow measuring element, the first flow measuring element being provided on the dredging circuit and being used to measure the flow of the thermal oil in the circuit;

[0091] a third oil drain tank, the third oil drain tank being used to connect to the lowest point of the heat collection loop;

[0092] The full circuit dredging step includes:

[0093] S51: After the oil in the circuit is drained, check whether the first on-off valve, the second on-off valve, the first oil drain valve, the second oil drain valve, and the third oil drain valve are in a closed state;

[0094] S52: connecting the outlet of the dredging pump and the second oil drain valve via the oil filling pipe, and connecting the inlet of the oil tank and the first oil drain valve via the oil return pipe to form a dredging circuit;

[0095] S53: Open the first oil drain valve and the second oil drain valve, and start the dredging pump;

[0096] S54: checking the flow rate change of the heat collection circuit by using the first flow measurement element, and adjusting the power of the dredging pump until the flow rate of the heat collection circuit reaches a preset normal value;

[0097] The segmented circuit dredging step includes:

[0098] S61: After the oil in the circuit is drained, check whether the first on-off valve, the second on-off valve, the first oil drain valve, the second oil drain valve, and the third oil drain valve are in a closed state;

[0099] S62: The outlet of the dredging pump is connected to the third oil drain valve, the first oil drain valve is connected to the first oil drain barrel, and the second oil drain valve is connected to the second oil drain barrel;

[0100] S63: After opening the first oil drain valve, the second oil drain valve, and the third oil drain valve, start the dredging pump;

[0101] S64: Check the first oil drain valve and the second oil drain valve, close the oil drain valve with oil flowing out first, and stop the dredging pump after the section from the third oil drain valve to the first oil drain valve and the section from the third oil drain valve to the second oil drain valve are unblocked.

[0102] By implementing the present invention, the following beneficial effects are achieved:

[0103] The present invention can realize rapid oil discharge of the heat collection circuit through the circuit oil withdrawal step with high efficiency, and isolate the heat transfer oil from air throughout the operation to avoid oxidation of the heat transfer oil. After the oil is discharged, the entire process of heat collection circuit maintenance work can be realized.

[0104] Through rigorous test procedures, the maintenance quality of the solar collector circuit can be effectively tested, improving efficiency while also enhancing safety and economy.

[0105] Through the loop oil filling step, the heat collection loop can be quickly filled with oil with high efficiency.

[0106] Through the heat loss measurement steps, the temperature of the heat transfer oil can be flexibly controlled to rise and fall, the vacuum performance of the collector in the heat collection circuit and the circuit insulation performance can be effectively evaluated, unqualified collectors can be replaced, and circuits with poor insulation performance can be strengthened and improved.

[0107] Through the full or segmented circuit dredging steps, the blockage problem of the solar collector circuit can be dredged online and efficiently, avoiding pipe cutting and disassembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0109] Figure 1 Schematic diagram of the composition of the heat collection circuit of the present invention;

[0110] Figure 2 This is a schematic diagram of the components of the parabolic trough solar thermal power station heat collection circuit maintenance equipment of the present invention. Figure 1 ;

[0111] Figure 3 This is a schematic diagram of the components of the parabolic trough solar thermal power station heat collection circuit maintenance equipment of the present invention. Figure 2 ;

[0112] Figure 4 Schematic diagram of the composition of the antioxidant device of the present invention;

[0113] Figure 5 1 is a schematic diagram of the composition of the control panel of the present invention;

[0114] Figure 6 It is a schematic diagram of the oil withdrawal of the circuit of the present invention;

[0115] Figure 7 It is a schematic diagram of the tightness test of the present invention;

[0116] Figure 8 It is a schematic diagram of the circuit oil filling and heat loss measurement of the present invention;

[0117] Figure 9 This is a schematic diagram of the forward full-section circuit dredging of the present invention;

[0118] Figure 10 This is a schematic diagram of the reverse full-segment circuit dredging of the present invention;

[0119] Figure 11 It is a schematic diagram of the segmented circuit dredging of the present invention. DETAILED DESCRIPTION

[0120] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0121] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0122] In the description of the invention, it should be noted that the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "plurality" means two or more.

[0123] The terms "mounted," "connected," "connected," "located at," and "located at" should be interpreted broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or chemical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0124] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0125] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0126] Traditional solar trough solar thermal power generation system technology uses thermal oil as a heat carrier, utilizing the optical principle of parabolas to concentrate solar energy. This energy is then directed to a collector, where the oil absorbs the sun's energy. As it flows through the solar field, its temperature gradually heats from 290°C to 390°C before exiting the field. A portion of the heated oil flows into a steam generator to exchange heat with water, then flows back to the field. The water, after exchange, becomes 375°C steam, driving a steam turbine to generate electricity. The remaining portion of the oil then exchanges heat with molten salt through a heat exchanger and flows back to the field. The molten salt is stored in a high-temperature salt tank and used to exchange heat with the oil at night, when there's no sunlight, for use in steam turbine power generation.

[0127] like Figure 1As shown, one embodiment of the present invention discloses a trough-type solar thermal power station heat collection circuit maintenance equipment, which is used to repair the trough-type solar thermal power station heat collection circuit. The heat collection circuit includes collectors LOC1-4 connected in series. The inlet of the heat collection circuit is connected to the oil mother pipe, which is a cold oil mother pipe. The outlet of the heat collection circuit is connected to the return oil mother pipe, which is a hot oil mother pipe.

[0128] A first on-off valve 11 and a first oil drain valve 12 are provided at one end of the heat collection circuit, and a second on-off valve 13 and a second oil drain valve 15 are provided at the other end. A third oil drain valve 16 is provided at the lowest point of the heat collection circuit. Preferably, one end of the heat collection circuit is the inlet and the other is the outlet. The first oil drain valve 12 is located at the outlet of the first on-off valve 11, and the second oil drain valve 15 is located at the inlet of the second on-off valve 13. A third on-off valve 14 is also provided at the outlet of the heat collection circuit, located between the second on-off valve 13 and the second oil drain valve 15.

[0129] In some other embodiments, one end of the heat collection circuit is the outlet end and the other end is the inlet end, the first oil drain valve 12 is located at the inlet end of the first switch valve 11, the second oil drain valve 15 is located at the outlet end of the second switch valve 13, and a third switch valve 14 is also provided at the outlet end of the heat collection circuit, and the third switch valve 14 is located between the first switch valve 11 and the first oil drain valve 12.

[0130] like Figure 2 and Figure 3 As shown, the maintenance equipment includes a mobile device 20, such as Figure 5 The control panel 21, oil tank 22, circulation pump 23, dredging pump 24, heater 25, oil level measuring element 26, first temperature measuring element 27, exhaust valve 28, stirrer 29, anti-oxidation device 30, first pressure measuring element, first flow measuring element, second temperature measuring element, oil drain pipe 42, air supply pipe 43, oil filling pipe 44, oil return pipe 45, quick connector 46, first oil drain barrel 47, second oil drain barrel 48 and third oil drain barrel 49 are shown in detail as follows:

[0131] The mobile device 20 is a loading vehicle. The oil tank 22 is provided on the mobile device 20 and is used to store thermal oil. The circulating pump 23 is provided at the outlet end of the oil tank 22 and is used to circulate the thermal oil. For example, the circulating pump 23 is a magnetic shielded pump, which is not limited here. The dredging pump 24 is provided at the outlet end of the oil tank 22. The circulating pump 23 can also be replaced by the dredging pump 24 when dredging is required. The dredging pump 24 is used to transport thermal oil for dredging. For example, the dredging pump 24 is a high-pressure pulsating pump, which is not limited here. The heater 25 is provided in the oil tank 22 and is used to heat the thermal oil. The oil level measuring element 26 is provided in the oil tank 22 and is used to measure the oil level in the oil tank 22. For example, the oil level measuring element 26 is an oil level gauge, which is not limited here. The first temperature measuring element 27 is provided in the oil tank 22 and is used to measure the temperature of the thermal oil in the oil tank 22. For example, the first temperature measuring element 27 is a thermometer, which is not limited here. An exhaust valve 28 is provided on the oil tank 22 for exhausting the gas in the oil tank 22. For example, the exhaust valve 28 is an automatic exhaust valve 28, which is not limited here. An agitator 29 is provided in the oil tank 22 for stirring the thermal oil uniformly.

[0132] like Figure 4 As shown, the anti-oxidation device 30 is provided on the mobile device 20 and is used to output anti-oxidation gas. The device 30 includes at least one gas tank 301, a gas outlet valve 302 provided at the outlet end of the gas tank 301, and a second pressure measuring element 303, a second flow measuring element 304, and a gas outlet regulating valve 305 provided at the outlet end of the gas outlet valve 302. For example, the gas tank 301 is a nitrogen tank 301, i.e., the anti-oxidation gas is nitrogen, the second pressure measuring element 303 is a pressure gauge, and the second flow measuring element 304 is a flow meter, but these are not limited here.

[0133] The first pressure measuring element is provided on the tightness test circuit to measure the circuit pressure. The first flow measuring element is provided on the oil filling circuit, the heat loss measurement circuit and the dredging circuit to measure the flow of thermal oil in the circuit. The second temperature measuring element is provided on the heat loss measurement circuit to measure the temperature of the thermal oil in the circuit. Preferably, the functions of the first pressure measuring element, the first flow measuring element and the second temperature measuring element are integrated into the combined measuring element 41. Among them, the tightness test circuit includes an air supply pipe 43 and a heat collecting pipe LOC4-1. The oil filling circuit, the heat loss measurement circuit and the dredging circuit include an oil filling pipe 44, a heat collecting pipe LOC4-1 and an oil return pipe 45.

[0134] The oil drain pipe 42 connects the first oil drain valve 12 to the inlet of the fuel tank 22. The gas pipe 43 connects the second oil drain valve 15 to the gas outlet valve 302. The oil filling pipe 44 connects the outlet of the circulation pump 23 to the second oil drain valve 15, the outlet of the dredging pump 24 to the second oil drain valve 15, and the outlet of the dredging pump 24 to the third oil drain valve 16. The oil return pipe 45 connects the inlet of the fuel tank 22 to the first oil drain valve 12. For example, the oil drain pipe 42, gas pipe 43, oil filling pipe 44, and oil return pipe 45 are all flexible pipes and are not limited to these.

[0135] The first oil drain barrel 47 is used to connect one end of the heat collection loop, the second oil drain barrel 48 is used to connect the other end of the heat collection loop, and the third oil drain barrel 49 is used to connect the lowest point of the heat collection loop.

[0136] And, as Figure 5 As shown, a control panel 21 is further provided at the rear of the loader, which includes a gas pressure display unit 210 for displaying the pressure value of the second pressure measuring element 303, a return oil pressure display unit 211 for displaying the pressure value of the first pressure measuring element during oil return, an injection pressure display unit 212 for displaying the pressure value of the first pressure measuring element during oil injection, an dredging pressure display unit 213 for displaying the pressure value of the first pressure measuring element during dredging, a heating control unit 214 for controlling the operation or stop of the heater 25, a circulation control unit 215 for controlling the operation or stop of the circulation pump 23, a dredging control unit 216 for controlling the operation or stop of the dredging pump 24, and an emergency control unit for emergency stopping of all electrical components. A stop control unit 217, a first operating unit 218 for manually operating the gas outlet valve 302, a second operating unit 219 for manually operating the first oil drain valve 12, a third operating unit 220 for manually operating the second oil drain valve 15, a fourth operating unit 221 for manually operating the third oil drain valve 16, a gas interface 222 for connecting the outlet of the gas outlet valve 302 to the gas pipe 43, an oil return interface 223 for connecting the inlet of the oil tank 22 to the return oil pipe 45 or the oil drain pipe 42, an oil filling interface 224 for connecting the outlet of the circulation pump 23 to the oil filling pipe 44, a dredging interface 225 for connecting the outlet of the dredging pump 24 to the oil filling pipe 44, and a touch screen 226.

[0137] A complete set of special maintenance equipment is designed based on the maintenance requirements and site characteristics of the parabolic trough solar thermal power station's collector circuit, which greatly improves the maintenance efficiency and safety. The centralized control function is designed to realize the control statistics of the circuit oil injection and oil withdrawal flow, monitor the oil temperature in each link throughout the process, and control, collect and analyze the circuit oil withdrawal, tightness test, oil injection, heat loss measurement and circuit blockage unblocking.

[0138] One embodiment of the present invention discloses a maintenance method for the solar trough power station collector circuit maintenance equipment based on the above-mentioned embodiment, comprising a circuit oil removal step, a tightness test step, a circuit oil filling step, a heat dissipation loss measurement step, a full circuit dredging step, and a segmented circuit dredging step, specifically as follows:

[0139] like Figure 6 As shown, the oil withdrawal steps of the circuit are: close both ends of the heat collection circuit, connect the inlet of the oil tank 22 to one end of the heat collection circuit, connect the anti-oxidation device 30 to the other end of the heat collection circuit, use the internal pressure of the heat collection circuit and the anti-oxidation gas to purge, recover the heat transfer oil in the heat collection circuit into the oil tank 22, and then perform maintenance on the heat collection circuit.

[0140] Specifically, the circuit oil withdrawal steps include:

[0141] S11: Close the first on-off valve 11 and the second on-off valve 13;

[0142] S12: Connect the first oil drain valve 12 and the inlet of the oil tank 22 via the oil drain pipe 42, and connect the second oil drain valve 15 and the gas outlet valve 302 via the gas pipe 43. For example, a quick connector 46 can be installed on the lower sides of the first oil drain valve 12 and the second oil drain valve 15, and connect the oil drain pipe 42 and the gas pipe 43 via the quick connector 46.

[0143] S13: Slowly open the first oil drain valve 12, control the oil drain speed, and use the internal pressure of the heat collection circuit to recover the thermal oil to the oil tank 22;

[0144] S14: When the oil level in the oil tank 22 stops rising, the gas outlet valve 302 is slowly opened and the second pressure measuring element 303 is checked. The pressure in the pipeline from the gas tank 301 to the second oil drain valve 15 is maintained at a first preset pressure value, for example, 0.5 kPa, which is not limited here.

[0145] S15: Slowly open the second oil drain valve 15 and use the anti-oxidation gas to purge the remaining thermal oil in the heat collection circuit into the oil tank 22;

[0146] S16: When the oil level in the oil tank 22 stops rising by checking through the oil level measuring element 26 and the third oil drain valve 16 is opened to check that no thermal oil flows out from the lowest point of the heat collection circuit, it is confirmed that all the thermal oil in the heat collection circuit has been drained, the gas outlet valve 302 is closed, the oil drain pipe 42 and the gas pipe 43 are removed, and the heat collection circuit is inspected and maintained.

[0147] Through the circuit oil withdrawal step, the heat collection circuit can be quickly drained with high efficiency, and the heat transfer oil is isolated from the air throughout the operation to avoid heat transfer oil oxidation. After draining the oil, the entire process of heat collection circuit maintenance work can be realized.

[0148] like Figure 7 As shown, the tightness test procedure is as follows: After the heat collection circuit maintenance is completed, the anti-oxidation device 30 is connected to the heat collection circuit to form a tightness test circuit. The tightness of the heat collection circuit is tested based on the pressure value of the first pressure measuring element (combined measuring element 41). It should be noted that the heat collection circuit maintenance can be the maintenance after the circuit oil removal step described above, or other maintenance, and is not limited here.

[0149] Specifically, the rigorous test steps include:

[0150] S21: After the heat collection circuit maintenance is completed and the status of each valve is confirmed to be normal, check whether the first switch valve 11, the second switch valve 13, the first oil drain valve 12 and the second oil drain valve 15 are in the closed state;

[0151] S22: Connect the second oil drain valve 15 and the gas outlet valve 302 via the gas pipe 43 to form a tightness test circuit;

[0152] S23: Open the gas outlet valve 302 and slowly open the second oil drain valve 15. The pressure of the heat collection circuit slowly rises. When the pressure of the heat collection circuit is checked by the first pressure measuring element (combined measuring element 41) to be a second preset pressure value, the gas outlet valve 302 is closed. The second preset pressure value is, for example, 0.2 kPa, which is not limited here.

[0153] S24: When the pressure value of the first pressure measuring element (combined measuring element 41) stops decreasing, for example, after maintaining no decrease for 1 hour, the gas outlet valve 302 is opened, and the second oil drain valve 15 is slowly opened. When the pressure of the heat collection circuit is checked by the first pressure measuring element to be a third preset pressure value, the gas outlet valve 302 is closed. The third preset pressure value is greater than the second preset pressure value, for example, 1 MPa, which is not limited here.

[0154] S25: When the pressure value of the first pressure measuring element (combined measuring element 41) stops decreasing, for example, after maintaining no decrease for one hour, the gas outlet valve 302 is opened, and the second oil drain valve 15 is slowly opened. When the pressure of the heat collection circuit is checked by the first pressure measuring element to be a fourth preset pressure value, the gas outlet valve 302 is closed. The fourth preset pressure value is greater than the third preset pressure value, for example, 3 MPa, which is not limited herein.

[0155] S26: When the pressure value of the first pressure measuring element (combined measuring element 41 ) stops decreasing, the test is passed. For example, the pressure value of the first pressure measuring element (combined measuring element 41 ) stops decreasing for 1 hour, which is not limited here.

[0156] Through rigorous test procedures, the maintenance quality of the solar collector circuit can be effectively tested, improving efficiency while also enhancing safety and economy.

[0157] like Figure 8 As shown, the circuit oil filling step: After the thermal collector circuit passes the tightness test, the inlet of the oil tank 22 is connected to one end of the thermal collector circuit, and the outlet of the circulation pump 23 is connected to the other end of the thermal collector circuit, forming an oil filling circuit. Circulating pump 23 is then started to fill the thermal collector circuit with oil. It should be noted that the tightness test of the thermal collector circuit can be the tightness test step described above or another tightness test, which is not limited here.

[0158] Specifically, the circuit oil filling steps include:

[0159] S31: After the tightness test of the heat collection circuit is passed, check that the first on-off valve 11, the second on-off valve 13, the first oil drain valve 12, the second oil drain valve 15 and the third oil drain valve 16 are in the closed state;

[0160] S32: Connect the outlet of the circulation pump 23 and the second oil drain valve 15 through the oil filling pipe 44, and connect the inlet of the oil tank 22 and the first oil drain valve 12 through the oil return pipe 45 to form an oil filling circuit;

[0161] S33: Open the first oil drain valve 12 and the second oil drain valve 15, and start the circulation pump 23 to fill the heat collection circuit with oil;

[0162] S34: After checking that the oil in the heat collection circuit is continuously flowing through the first flow measuring element (combined measuring element 41) and that the oil level in the oil tank 22 is stable through the oil level measuring element 26, the circulation pump 23 is stopped, the first oil drain valve 12 and the second oil drain valve 15 are closed, and the oil filling is completed.

[0163] In some other embodiments, it is not necessary to check whether the second switch valve 13 is in the closed state, but it is possible to check whether the third switch valve 14 is in the closed state.

[0164] Through the loop oil filling step, the heat collection loop can be quickly filled with oil with high efficiency.

[0165] like Figure 8 As shown, the heat loss measurement steps are as follows: After the heat collection circuit is filled with oil, the inlet of the oil tank 22 is connected to one end of the heat collection circuit, and the outlet of the circulation pump 23 is connected to the other end of the heat collection circuit, forming a heat loss measurement circuit. The circulation pump 23 is kept running, and the heater 25 is turned on to increase the temperature of the thermal oil in the heat collection circuit. The second temperature measuring element (combined measuring element 41) continuously collects temperature data for a preset period of time, and the heat loss is evaluated based on the temperature drop of the thermal oil. It should be noted that the heat collection circuit can be filled with oil in the circuit as described above, or in other circuits, and this is not limited here.

[0166] Specifically, the heat loss measurement steps include:

[0167] S41: After the heat collection circuit is filled with oil, the oil filling pipe 44 is connected to the outlet of the circulation pump 23 and the second oil drain valve 15, and the oil return pipe 45 is connected to the inlet of the oil tank 22 and the first oil drain valve 12, forming a heat loss measurement circuit. The circulation pump 23 is kept running, the first oil drain valve 12 is opened, the second oil drain valve 15 is opened, the first on-off valve 11 is closed, and the second on-off valve 13 is closed. The heater 25 is started to heat the heat transfer oil in the heat collection circuit.

[0168] S42: When the temperature of the heat transfer oil in the heat collection circuit rises to a preset temperature value through the first temperature measuring element 27, the heater 25 is stopped, the circulation pump 23 is kept running, and the flow rate of the heat transfer oil in the heat collection circuit is controlled to a preset flow rate value through the first flow measuring element (combined measuring element 41). For example, the preset temperature value is 100°C and the preset flow rate value is 25T / hour, which is not limited here.

[0169] S43: Continuously collect the preset time of the heat collection circuit through the second temperature measuring element (combined measuring element 41), and evaluate the heat dissipation loss according to the temperature drop value of the heat transfer oil. The smaller the temperature drop value, the smaller the heat dissipation loss, indicating that the heat collection circuit has good performance and good insulation effect. For example, the preset time is 4 hours, which is not limited here.

[0170] By designing the thermal insulation heating oil tank 22, the heat transfer oil temperature can be flexibly controlled to rise and fall through the heat loss measurement step, and the vacuum performance of the collector in the heat collection circuit and the circuit insulation performance can be effectively evaluated. Unqualified collectors can be replaced, and circuits with poor insulation performance can be strengthened and improved.

[0171] like Figure 9 and Figure 10 As shown, the heat collection circuit can sometimes become clogged with oil sludge, necessitating dredging. The full circuit dredging steps are as follows: After the circuit is de-oiled, the outlet of the dredging pump 24 is connected to one end of the heat collection circuit, and the inlet of the oil tank 22 is connected to the other end of the heat collection circuit, forming a dredging circuit. The dredging pump 24 is then started to dredge the heat collection circuit. It should be noted that the circuit de-oiling can be performed in the aforementioned circuit de-oiling step or in other circuit de-oiling steps, and this is not limited here. Preferably, the dredging pump 24 is a high-pressure pulsating pump.

[0172] Specifically, if Figure 10 As shown, the steps for clearing the entire circuit include:

[0173] S51: After the oil in the circuit is drained, check that the first on-off valve 11, the second on-off valve 13, the first oil drain valve 12, the second oil drain valve 15 and the third oil drain valve 16 are in the closed state;

[0174] S52: Connect the outlet of the dredging pump 24 to the second oil drain valve 15 through the oil filling pipe 44, and connect the inlet of the oil tank 22 to the first oil drain valve 12 through the oil return pipe 45 to form a dredging circuit;

[0175] S53: Open the first oil drain valve 12 and the second oil drain valve 15, and start the dredging pump 24;

[0176] S54: Check the flow change of the heat collection circuit through the first flow measuring element (combined measuring element 41), and adjust the power of the dredging pump 24 until the flow of the heat collection circuit reaches a preset normal value, for example, the preset normal value is 25T / hour, which is not limited here.

[0177] In addition, the third oil drain valve 16 can be connected to the third oil drain barrel 49. When the section from the first oil drain valve 12 to the third oil drain valve 16 or the section from the second oil drain valve 15 to the third oil drain valve 16 is blocked, the third oil drain valve 16 can be opened to narrow the dredging range.

[0178] In some other embodiments, it is not necessary to check whether the second switch valve 13 is in the closed state, but it is possible to check whether the third switch valve 14 is in the closed state.

[0179] Among them, when the first switch valve 11 and the first oil drain valve 12 are set at the outlet end of the heat collection circuit, and the second switch valve 13 and the second oil drain valve 15 are set at the inlet end of the heat collection circuit, the steps for clearing the entire circuit are as follows: Figure 9 When the first switch valve 11 and the first oil drain valve 12 are located at the inlet of the heat collection circuit, and the second switch valve 13 and the second oil drain valve 15 are located at the outlet of the heat collection circuit, the steps for unclogging the entire circuit are as follows: Figure 10 The reverse full-section circuit shown is unblocked.

[0180] like Figure 11 As shown, when both forward and reverse directions are unable to clear the circuit, a segmented circuit clearing procedure can be used: after the circuit oil is drained, one end of the heat collection circuit is connected to the first oil drain barrel 47, and the other end of the heat collection circuit is connected to the second oil drain barrel 48. The outlet of the clearing pump 24 is connected to the segmented point of the heat collection circuit. The clearing pump 24 is then started to clear the segments of the heat collection circuit. It should be noted that the circuit oil draining procedure described above can be used, or other circuit oil draining procedures are not limited here. Preferably, the clearing pump 24 is a high-pressure pulsating pump.

[0181] Specifically, the steps for dredging the segmented circuit include:

[0182] S61: After the oil in the circuit is drained, check that the first on-off valve 11, the second on-off valve 13, the first oil drain valve 12, the second oil drain valve 15 and the third oil drain valve 16 are in the closed state;

[0183] S62: The outlet of the dredging pump 24 is connected to the third oil drain valve 16, the first oil drain valve 12 is connected to the first oil drain barrel 47, and the second oil drain valve 15 is connected to the second oil drain barrel 48;

[0184] S63: After opening the first oil drain valve 12, the second oil drain valve 15 and the third oil drain valve 16, the dredging pump 24 is started;

[0185] S64: Check the first oil drain valve 12 and the second oil drain valve 15, first close the oil drain valve with oil flowing out, and stop the dredging pump 24 after the section from the third oil drain valve 16 to the first oil drain valve 12 and the section from the third oil drain valve 16 to the second oil drain valve 15 are unblocked.

[0186] In some other embodiments, it is not necessary to check whether the second switch valve 13 is in the closed state, but it is possible to check whether the third switch valve 14 is in the closed state.

[0187] Through the full or segmented circuit dredging steps, the blockage problem of the solar collector circuit can be dredged online and efficiently, avoiding pipe cutting and disassembly.

[0188] It can be understood that the above embodiments only express some implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above embodiments or technical features can be freely combined, and several deformations and improvements can be made, which all fall within the scope of protection of the present invention, that is, the embodiments described in "some embodiments" can be freely combined with any of the above and below embodiments; therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A maintenance method for a parabolic trough solar thermal power station collector circuit maintenance equipment, characterized in that: Maintenance equipment includes: An oil tank (22), wherein the oil tank (22) is used to store heat transfer oil; an anti-oxidation device (30), the anti-oxidation device (30) being used to output anti-oxidation gas; a first pressure measuring element, the first pressure measuring element being provided on the tightness test loop and being used to measure the loop pressure; A dredging pump (24), the dredging pump (24) being arranged at the outlet end of the oil tank (22) and being used for conveying heat transfer oil for dredging; A first oil drain barrel (47) and a second oil drain barrel (48); The maintenance method comprises the following steps: Loop oil withdrawal step: closing both ends of the heat collection loop, connecting the inlet of the oil tank (22) to one end of the heat collection loop, and connecting the anti-oxidation device (30) to the other end of the heat collection loop, utilizing the internal pressure of the heat collection loop and the anti-oxidation gas to purge, recovering the heat transfer oil in the heat collection loop into the oil tank (22), and then performing maintenance on the heat collection loop; Tightness test step: after the heat collection circuit is overhauled, the anti-oxidation device (30) is connected to the heat collection circuit to form a tightness test circuit, and the tightness of the heat collection circuit is tested according to the pressure value of the first pressure measuring element; The whole circuit unclogging step: after the oil in the circuit is drained, the outlet of the unclogging pump (24) is connected to one end of the heat collection circuit, and the inlet of the oil tank (22) is connected to the other end of the heat collection circuit to form an unclogging circuit, and the unclogging pump (24) is started to unclog the heat collection circuit; or, the segmented circuit unclogging step: after the oil in the circuit is drained, one end of the heat collection circuit is connected to the first oil drain barrel (47), and the other end of the heat collection circuit is connected to the second oil drain barrel (48), and the outlet of the unclogging pump (24) is connected to the segmentation point of the heat collection circuit, and the unclogging pump (24) is started to unclog the segments on the heat collection circuit.

2. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 1, characterized in that: The maintenance equipment also includes: A circulation pump (23), the circulation pump (23) being arranged at the outlet end of the oil tank (22) and being used for circulating the heat transfer oil; The maintenance method further comprises: Loop oil filling step: After the tightness test of the heat collection loop is passed, the inlet of the oil tank (22) is connected to one end of the heat collection loop, and the outlet of the circulation pump (23) is connected to the other end of the heat collection loop to form an oil filling loop, and the circulation pump (23) is started to fill the heat collection loop with oil.

3. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 1, characterized in that: The maintenance equipment also includes: a circulation pump (23), the circulation pump (23) being arranged at the outlet end of the oil tank (22) and being used for conveying heat transfer oil; a heater (25), the heater (25) being disposed in the oil tank (22) and being used for heating the thermal oil; a second temperature measuring element, the second temperature measuring element being provided on the heat loss measurement circuit and being used to measure the temperature of the heat transfer oil in the circuit; The maintenance method further comprises: Heat loss measurement steps: After the heat collection circuit is filled with oil, the inlet of the oil tank (22) is connected to one end of the heat collection circuit, and the outlet of the circulation pump (23) is connected to the other end of the heat collection circuit to form a heat loss measurement circuit, the circulation pump (23) is kept running, the heater (25) is turned on to heat the heat transfer oil in the heat collection circuit, and the second temperature measuring element is used to continuously collect the preset time, and the heat loss is evaluated according to the temperature drop value of the heat transfer oil.

4. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 1, characterized in that: A first on-off valve (11) and a first oil drain valve (12) are provided at one end of the heat collection loop, and a second on-off valve (13) and a second oil drain valve (15) are provided at the other end of the heat collection loop; a third oil drain valve (16) is provided at the lowest point of the heat collection loop; The anti-oxidation device (30) comprises: at least one gas tank (301), a gas outlet valve (302) provided at the outlet end of the gas tank (301), and a second pressure measuring element (303) provided at the outlet end of the gas outlet valve (302); The maintenance equipment also includes: an oil level measuring element (26), the oil level measuring element (26) being disposed in the oil tank (22) and being used to measure the oil level in the oil tank (22); an oil drain pipe (42), the oil drain pipe (42) being used to connect the first oil drain valve (12) and the inlet of the oil tank (22); an air delivery pipe (43), the air delivery pipe (43) being used to connect the second oil discharge valve (15) and the gas outlet valve (302); The circuit oil withdrawal step includes: S11: closing the first on-off valve (11) and the second on-off valve (13); S12: connecting the first oil drain valve (12) and the inlet of the oil tank (22) via the oil drain pipe (42), and connecting the second oil drain valve (15) and the gas outlet valve (302) via the gas pipe (43); S13: slowly opening the first oil drain valve (12) and utilizing the internal pressure of the heat collection circuit to recover the heat transfer oil to the oil tank (22); S14: When the oil level in the oil tank (22) stops rising after checking with the oil level measuring element (26), slowly open the gas outlet valve (302), check the second pressure measuring element (303), and maintain the pressure of the pipeline from the gas tank (301) to the second oil drain valve (15) at a first preset pressure value; S15: slowly opening the second oil drain valve (15) and using the anti-oxidation gas to purge the remaining heat transfer oil in the heat collection circuit into the oil tank (22); S16: When the oil level in the oil tank (22) stops rising by checking with the oil level measuring element (26) and the third oil drain valve (16) is opened to check that no heat transfer oil flows out, it is confirmed that all the heat transfer oil in the heat collection circuit has been drained, the gas outlet valve (302) is closed, the oil drain pipe (42) and the gas supply pipe (43) are disassembled, and the heat collection circuit is repaired.

5. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 1, characterized in that: A first on-off valve (11) and a first oil drain valve (12) are provided at one end of the heat collection loop, and a second on-off valve (13) and a second oil drain valve (15) are provided at the other end of the heat collection loop; a third oil drain valve (16) is provided at the lowest point of the heat collection loop; The anti-oxidation device (30) comprises: at least one gas tank (301), a gas outlet valve (302) provided at the outlet end of the gas tank (301), and a second pressure measuring element (303) provided between the outlet of the gas tank (301) and the gas outlet valve (302); The maintenance equipment also includes: an air delivery pipe (43), the air delivery pipe (43) being used to connect the second oil discharge valve (15) and the gas outlet valve (302); The tightness test steps include: S21: After the heat collection circuit is overhauled and the status of each valve is confirmed to be normal, check whether the first on-off valve (11), the second on-off valve (13), the first oil drain valve (12) and the second oil drain valve (15) are in a closed state; S22: Connecting the second oil discharge valve (15) and the gas outlet valve (302) via the gas transmission pipe (43) to form a tightness test circuit; S23: Open the gas outlet valve (302), slowly open the second oil drain valve (15), and when the pressure of the heat collection circuit is checked to be a second preset pressure value by the first pressure measuring element, close the gas outlet valve (302); S24: when the pressure value of the first pressure measuring element stops decreasing, the gas outlet valve (302) is opened, the second oil drain valve (15) is continued to be slowly opened, and when the pressure of the heat collection circuit is checked by the first pressure measuring element to be a third preset pressure value, the gas outlet valve (302) is closed; wherein the third preset pressure value is greater than the second preset pressure value; S25: when the pressure value of the first pressure measuring element stops decreasing, the gas outlet valve (302) is opened, the second oil drain valve (15) is continued to be slowly opened, and when the pressure of the heat collection circuit is checked by the first pressure measuring element to be a fourth preset pressure value, the gas outlet valve (302) is closed; wherein the fourth preset pressure value is greater than the third preset pressure value; S26: When the pressure value of the first pressure measuring element does not drop, the test is passed.

6. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 2, characterized in that: A first on-off valve (11) and a first oil drain valve (12) are provided at one end of the heat collection loop, and a second on-off valve (13) and a second oil drain valve (15) are provided at the other end of the heat collection loop; a third oil drain valve (16) is provided at the lowest point of the heat collection loop; The maintenance equipment also includes: an oil level measuring element (26), the oil level measuring element (26) being disposed in the oil tank (22) and being used to measure the oil level in the oil tank (22); an oil filling pipe (44), the oil filling pipe (44) being used to connect the outlet of the circulation pump (23) and the second oil drain valve (15); an oil return pipe (45), the oil return pipe (45) being used to connect the inlet of the oil tank (22) and the first oil drain valve (12); a first flow measuring element, the first flow measuring element being provided on the oil injection circuit and being used to measure the flow rate of the thermal oil in the circuit; The circuit oil filling step comprises: S31: After the tightness test of the heat collection circuit is passed, check that the first on-off valve (11), the second on-off valve (13), the first oil drain valve (12), the second oil drain valve (15) and the third oil drain valve (16) are in a closed state; S32: connecting the outlet of the circulation pump (23) and the second oil drain valve (15) via the oil filling pipe (44), and connecting the inlet of the oil tank (22) and the first oil drain valve (12) via the oil return pipe (45), thereby forming an oil filling circuit; S33: opening the first oil drain valve (12) and the second oil drain valve (15), and starting the circulation pump (23) to fill the heat collection circuit with oil; S34: After checking that the oil in the heat collection circuit is continuously flowing through the first flow measuring element and that the oil level in the oil tank (22) is stable through the oil level measuring element (26), the circulation pump (23) is stopped, the first oil drain valve (12) and the second oil drain valve (15) are closed, and the oil filling is completed.

7. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 3, characterized in that: A first switch valve (11) and a first oil drain valve (12) are provided at one end of the heat collection circuit, and a second switch valve (13) and a second oil drain valve (15) are provided at the other end of the heat collection circuit. The maintenance equipment also includes: a first temperature measuring element (27), the first temperature measuring element (27) being disposed in the oil tank (22) and being used to measure the temperature of the heat transfer oil in the oil tank (22); a first flow measuring element, the first flow measuring element being provided on the heat loss measurement circuit and being used to measure the flow of the thermal oil in the circuit; a second temperature measuring element, the second temperature measuring element being provided on the heat loss measurement circuit and being used to measure the temperature of the heat transfer oil in the circuit; an oil filling pipe (44), the oil filling pipe (44) being used to connect the outlet of the circulation pump (23) and the second oil drain valve (15); an oil return pipe (45), the oil return pipe (45) being used to connect the inlet of the oil tank (22) and the first oil drain valve (12); The heat loss measurement step comprises: S41: After the oil filling of the heat collection circuit is completed, the oil filling pipe (44) is connected to the outlet of the circulation pump (23) and the second oil drain valve (15), and the oil return pipe (45) is connected to the inlet of the oil tank (22) and the first oil drain valve (12), forming a heat loss measurement circuit, keeping the circulation pump (23) running, the first oil drain valve (12) open, the second oil drain valve (15) open, the first on-off valve (11) closed, and the second on-off valve (13) closed, and starting the heater (25) to heat the heat transfer oil in the heat collection circuit; S42: When the temperature of the heat transfer oil in the heat collection circuit is detected to rise to a preset temperature value by the first temperature measuring element (27), the heater (25) is stopped, the circulation pump (23) is kept running, and the flow rate of the heat transfer oil in the heat collection circuit is controlled to a preset flow rate value by the first flow measuring element; S43: Continuously collecting data from the heat collection circuit for a preset time through the second temperature measuring element, and evaluating the heat dissipation loss according to the temperature drop value of the thermal oil.

8. The maintenance method of the parabolic trough power station heat collection circuit maintenance equipment according to claim 1, characterized in that: A first on-off valve (11) and a first oil drain valve (12) are provided at one end of the heat collection loop, and a second on-off valve (13) and a second oil drain valve (15) are provided at the other end of the heat collection loop; a third oil drain valve (16) is provided at the lowest point of the heat collection loop; The maintenance equipment also includes: an oil filling pipe (44), the oil filling pipe (44) being used to connect the outlet of the dredging pump (24) and the second oil discharge valve (15) or the third oil discharge valve (16); an oil return pipe (45), the oil return pipe (45) being used to connect the inlet of the oil tank (22) and the first oil drain valve (12); a first flow measuring element, the first flow measuring element being provided on the dredging circuit and being used to measure the flow of the thermal oil in the circuit; a third oil drain barrel (49), the third oil drain barrel (49) being used to connect to the lowest point of the heat collection circuit; The full circuit dredging step includes: S51: After the oil in the circuit is drained, check that the first on-off valve (11), the second on-off valve (13), the first oil drain valve (12), the second oil drain valve (15) and the third oil drain valve (16) are in a closed state; S52: Connecting the outlet of the dredging pump (24) and the second oil drain valve (15) via the oil filling pipe (44), and connecting the inlet of the oil tank (22) and the first oil drain valve (12) via the oil return pipe (45) to form a dredging circuit; S53: opening the first oil drain valve (12) and the second oil drain valve (15), and starting the dredging pump (24); S54: checking the flow change of the heat collection circuit through the first flow measuring element, and adjusting the power of the dredging pump (24) until the flow of the heat collection circuit reaches a preset normal value; The segmented circuit dredging step includes: S61: After the oil in the circuit is drained, check that the first on-off valve (11), the second on-off valve (13), the first oil drain valve (12), the second oil drain valve (15) and the third oil drain valve (16) are in a closed state; S62: The outlet of the dredging pump (24) is connected to the third oil drain valve (16), the first oil drain valve (12) is connected to the first oil drain barrel (47), and the second oil drain valve (15) is connected to the second oil drain barrel (48); S63: After opening the first oil drain valve (12), the second oil drain valve (15), and the third oil drain valve (16), the dredging pump (24) is started; S64: Check the first oil drain valve (12) and the second oil drain valve (15), first close the oil drain valve with oil flowing out, and stop the dredging pump (24) after the section from the third oil drain valve (16) to the first oil drain valve (12) and the section from the third oil drain valve (16) to the second oil drain valve (15) are dredged.

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