Thermal power unit coupled with molten salt energy storage system, monitoring system and regulation method

Abstract

The present application relates to the field of thermal power unit coupling energy storage, and discloses a thermal power unit coupling molten salt energy storage system, a monitoring system and a regulation and control method. In the system, the outlet of the steam output pipeline of the thermal power unit is communicated with the steam inlet of the first heat exchanger, and the steam outlet of the first heat exchanger is communicated with the steam inlet of the second heat exchanger. The outlet of the low-temperature molten salt tank is communicated with the molten salt inlet of the second heat exchanger, the molten salt outlet of the second heat exchanger is communicated with the molten salt inlet of the first heat exchanger, and the molten salt outlet of the first heat exchanger is communicated with the inlet of the high-temperature molten salt tank. Through the segmented heat exchange arrangement, the first heat exchanger and the second heat exchanger are arranged to progressively utilize the heat energy of the high-temperature and high-pressure steam, so that the heat transfer temperature difference in the heat exchange process can be reduced, thereby the heat loss in the heat transfer process can be reduced, and the utilization rate of the high-temperature and high-pressure steam heat energy can be improved. Moreover, by arranging the monitoring system and the regulation and control method, the safety and reliability and the economy of the system operation can be ensured.

Description

Technical Field

[0001] This invention relates to the field of thermal power unit coupled energy storage technology, specifically to a thermal power unit coupled molten salt energy storage system, a monitoring system, and a control method. Background Technology

[0002] Molten salt energy storage has great application potential in the field of energy storage coupled with thermal power units due to its advantages such as low saturated vapor pressure, low viscosity, and high specific heat capacity. Coupled with thermal power units, molten salt energy storage can solve the problem of insufficient power peak-shaving capacity in power plants.

[0003] However, current schemes for coupling thermal power units with molten salt energy storage mostly utilize the high-temperature, high-pressure steam output from the thermal power unit to directly heat the low-temperature molten salt output from the cryogenic molten salt tank. The large temperature difference between the high-temperature, high-pressure steam and the low-temperature molten salt results in significant heat loss during the heat transfer process, leading to low thermal energy utilization of the high-temperature, high-pressure steam. Furthermore, due to the large temperature difference, the operating conditions change frequently, drastically, and complexly, posing a severe challenge to the system's process safety and stability. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of existing technologies that use high-temperature and high-pressure steam output from thermal power units to directly heat low-temperature molten salt output from low-temperature molten salt tanks, resulting in large heat loss and low thermal utilization rate of high-temperature and high-pressure steam. The invention provides a thermal power unit coupled with molten salt energy storage system, a monitoring system, and a control method.

[0005] To achieve the above objectives, the first aspect of the present invention provides a thermal power unit coupled with molten salt energy storage system, the thermal power unit coupled with molten salt energy storage system comprising a thermal power unit steam output pipeline, a first heat exchanger, a second heat exchanger, a low-temperature molten salt tank and a high-temperature molten salt tank;

[0006] The outlet of the steam output pipeline of the thermal power unit is connected to the steam inlet of the first heat exchanger, and the steam outlet of the first heat exchanger is connected to the steam inlet of the second heat exchanger.

[0007] The outlet of the low-temperature molten salt tank is connected to the molten salt inlet of the second heat exchanger, the molten salt outlet of the second heat exchanger is connected to the molten salt inlet of the first heat exchanger, and the molten salt outlet of the first heat exchanger is connected to the inlet of the high-temperature molten salt tank.

[0008] In this embodiment of the application, the thermal power unit coupled molten salt energy storage system further includes a de-cooling and pressure reducing device, which is installed on the steam output pipeline of the thermal power unit.

[0009] In the embodiment of the present application, the thermal power unit coupled molten salt energy storage system further comprises a condensate water output pipeline; an inlet of the condensate water output pipeline is in communication with a condensate water outlet of the second heat exchanger.

[0010] The second aspect of the present application provides a monitoring system for monitoring the thermal power unit coupled molten salt energy storage system of the first aspect;

[0011] The monitoring system comprises a controller and an operation performance detection device and a safety performance detection device arranged in the thermal power unit coupled molten salt energy storage system, and the operation performance detection device and the safety performance detection device are connected with the controller.

[0012] In the embodiment of the present application, the operation performance detection device comprises a first temperature detection device, a second temperature detection device, a third temperature detection device, a fourth temperature detection device, a fifth temperature detection device and a sixth temperature detection device;

[0013] The first temperature detection device is arranged on the steam output pipeline of the thermal power unit, the second temperature detection device is arranged on a pipeline for communicating a steam outlet of the first heat exchanger with a steam inlet of the second heat exchanger, the third temperature detection device is arranged on the condensate water output pipeline, the fourth temperature detection device is arranged on a pipeline for communicating an outlet of the low-temperature molten salt tank with a molten salt inlet of the second heat exchanger, the fifth temperature detection device is arranged on a pipeline for communicating a molten salt outlet of the second heat exchanger with a molten salt inlet of the first heat exchanger, and the sixth temperature detection device is arranged on a pipeline for communicating a molten salt outlet of the first heat exchanger with an inlet of the high-temperature molten salt tank.

[0014] In the embodiment of the present application, the operation performance detection device further comprises a flow detection device, and the flow detection device is arranged on the condensate water output pipeline.

[0015] In the embodiment of the present application, the safety performance detection device comprises a first stress detection device, a second stress detection device, a third stress detection device and a fourth stress detection device;

[0016] The first stress detection device is arranged at a steam inlet of the first heat exchanger, the second stress detection device is arranged at a molten salt outlet of the first heat exchanger, the third stress detection device is arranged at a steam inlet of the second heat exchanger, and the fourth stress detection device is arranged at a molten salt outlet of the first heat exchanger.

[0017] The third aspect of the present application provides a regulation method for regulating the thermal power unit coupled molten salt energy storage system of the first aspect based on the monitoring system of the second aspect, and the regulation method comprises:

[0018] determine an operation state of the thermal power generating unit coupled with the molten salt energy storage system based on the target parameters monitored by the monitoring system; the target parameters include parameters related to operation performance of the thermal power generating unit coupled with the molten salt energy storage system and parameters related to safety performance of the thermal power generating unit coupled with the molten salt energy storage system;

[0019] determine a control strategy according to the operation state and a preset index, and control the operation of the thermal power generating unit coupled with the molten salt energy storage system based on the control strategy.

[0020] In the embodiments of the present application, the operation state of the thermal power generating unit coupled with the molten salt energy storage system is determined based on the target parameters monitored by the monitoring system, and the operation state of the thermal power generating unit coupled with the molten salt energy storage system includes:

[0021] a first operation state of the thermal power generating unit coupled with the molten salt energy storage system is determined based on the parameters related to operation performance of the thermal power generating unit coupled with the molten salt energy storage system in the target parameters;

[0022] a second operation state of the thermal power generating unit coupled with the molten salt energy storage system is determined based on the parameters related to safety performance of the thermal power generating unit coupled with the molten salt energy storage system in the target parameters;

[0023] a target operation state is determined from the first operation state and the second operation state as the operation state of the thermal power generating unit coupled with the molten salt energy storage system.

[0024] In the embodiments of the present application, the first operation state of the thermal power generating unit coupled with the molten salt energy storage system is determined based on the parameters related to operation performance of the thermal power generating unit coupled with the molten salt energy storage system in the target parameters, and the first operation state of the thermal power generating unit coupled with the molten salt energy storage system includes:

[0025] the first operation state of the thermal power generating unit coupled with the molten salt energy storage system is determined based on the upper end temperature difference of the first heat exchanger, the lower end temperature difference of the first heat exchanger, the lower end temperature difference of the second heat exchanger, the flow rate, and the operating current of the molten salt pump.

[0026] By the technical scheme, the thermal power generating unit coupled molten salt energy storage system comprises a thermal power generating unit steam output pipeline, a first heat exchanger, a second heat exchanger, a low-temperature molten salt tank and a high-temperature molten salt tank; an outlet of the thermal power generating unit steam output pipeline is in communication with a steam inlet of the first heat exchanger, a steam outlet of the first heat exchanger is in communication with a steam inlet of the second heat exchanger; an outlet of the low-temperature molten salt tank is in communication with a molten salt inlet of the second heat exchanger, a molten salt outlet of the second heat exchanger is in communication with a molten salt inlet of the first heat exchanger, and a molten salt outlet of the first heat exchanger is in communication with an inlet of the high-temperature molten salt tank. By arranging the first heat exchanger and the second heat exchanger, the heat energy of the high-temperature and high-pressure steam is progressively utilized, so that the heat transfer temperature difference in the heat exchange process can be reduced, and thus the heat loss in the heat transfer process can be reduced, and the utilization rate of the high-temperature and high-pressure steam heat energy can be improved. Moreover, by arranging the monitoring system and the control method, the safety and reliability and the economy of the system operation can be ensured.

[0027] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation part to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0029] Figure 1 A structure schematic diagram of a thermal power generating unit coupled molten salt energy storage system according to an embodiment of the present application is schematically shown;

[0030] Figure 2 A flow schematic diagram of a control method according to an embodiment of the present application is schematically shown.

[0031] Explanation of reference signs

[0032] 101 - steam output pipeline of steam turbine; 102 - first heat exchanger; 103 - second heat exchanger; 104 - low-temperature molten salt tank; 105 - high-temperature molten salt tank; 106 - manual regulating valve; 107 - electric regulating valve; 108 - condensate water output pipeline; 109 - pressure reducing valve; 110 - desuperheating water pipeline; 111 - low-temperature molten salt pump; 112 - high-temperature molten salt pump; 113 - low-temperature molten salt input pipeline; 201 - first temperature detecting device; 202 - second temperature detecting device; 203 - third temperature detecting device; 204 - fourth temperature detecting device; 205 - fifth temperature detecting device; 206 - sixth temperature detecting device; 207 - first pressure detecting device; 208 - second pressure detecting device; 209 - flow detecting device; 210 - first stress detecting device; 211 - second stress detecting device; 212 - third stress detecting device; 213 - fourth stress detecting device; 214 - fifth stress detecting device; 215 - sixth stress detecting device; 216 - high-temperature molten salt sampling port; 217 - low-temperature molten salt sampling port; 218 - first optical fiber type liquid level monitoring device; 219 - second optical fiber type liquid level monitoring device. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain and illustrate the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0034] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0035] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0036] As described in the background section, current solutions for coupling thermal power units with molten salt energy storage mostly involve using the high-temperature, high-pressure steam output from the thermal power unit to directly heat the low-temperature molten salt output from the low-temperature molten salt tank. The large temperature difference between the high-temperature, high-pressure steam and the low-temperature molten salt results in significant heat loss during the heat transfer process, leading to low thermal utilization of the high-temperature, high-pressure steam.

[0037] To address this, one embodiment of this application provides a thermal power unit coupled with molten salt energy storage system, such as... Figure 1 As shown, the system may include a steam output pipeline 101 of a thermal power unit, a first heat exchanger 102, a second heat exchanger 103, a low-temperature molten salt tank 104, and a high-temperature molten salt tank 105; the outlet of the steam output pipeline 101 of the thermal power unit is connected to the steam inlet of the first heat exchanger 102, and the steam outlet of the first heat exchanger 102 is connected to the steam inlet of the second heat exchanger 103; the outlet of the low-temperature molten salt tank 104 is connected to the molten salt inlet of the second heat exchanger 103, the molten salt outlet of the second heat exchanger 103 is connected to the molten salt inlet of the first heat exchanger 102, and the molten salt outlet of the first heat exchanger 102 is connected to the inlet of the high-temperature molten salt tank 105.

[0038] The steam output pipeline 101 of the thermal power unit can be used to output high-temperature and high-pressure steam, also known as superheated steam, to the first heat exchanger 102. This high-temperature and high-pressure steam can be either main steam or reheat steam from the unit. To facilitate control of the output of high-temperature and high-pressure steam to the first heat exchanger 102, a manual regulating valve 106 and an electric regulating valve 107 can be installed on the steam output pipeline 101 of the thermal power unit.

[0039] In this embodiment, the first heat exchanger 102 can also be referred to as a high-temperature heat exchanger. During the heat exchange process, high-temperature, high-pressure steam enters the heat transfer tubes inside the first heat exchanger 102 through the steam inlet, and molten salt enters the shell of the first heat exchanger 102 through the molten salt inlet. The high-temperature, high-pressure steam transfers heat to the molten salt. After the heat exchange is completed, the cooled steam (also referred to as saturated steam) flows out from the steam outlet of the first heat exchanger 102 and flows into the high-temperature molten salt tank 105; the heated molten salt flows out from the molten salt outlet of the first heat exchanger 102 and flows into the second heat exchanger 103.

[0040] The second heat exchanger 103 can also be referred to as a low-temperature heat exchanger, and the definition of low temperature is relative to the high-temperature heat exchanger described above. In the heat exchange process, the saturated steam enters the heat transfer pipe in the second heat exchanger 103 from the steam inlet of the second heat exchanger 103, and the molten salt enters the shell of the second heat exchanger 103 from the molten salt inlet of the second heat exchanger 103, and the saturated steam transfers heat to the molten salt. After the heat exchange is completed, the saturated steam becomes condensed water (which can also be referred to as drain water) and flows out from the condensed water outlet of the second heat exchanger 103, and the molten salt with a higher temperature flows out from the molten salt outlet of the second heat exchanger 103 and flows into the first heat exchanger 102. In a specific implementation, the thermal power generating unit coupled with the molten salt energy storage system can further include a condensed water output pipeline 108, an inlet of the condensed water output pipeline 108 is in communication with the condensed water outlet of the second heat exchanger 103, and an outlet of the condensed water output pipeline 108 is connected to the thermal system of the unit. In this way, the condensed water output by the second heat exchanger 103 can be introduced into the thermal system of the unit for reuse, for example, the condensed water can be introduced into a deaerator in the thermal system of the unit.

[0041] In other words, in the embodiment of the present application, the low-temperature molten salt output by the low-temperature molten salt tank 104 is first subjected to heat exchange with the saturated steam with a lower temperature in the second heat exchanger 103, to obtain molten salt with a higher temperature. The molten salt with a higher temperature is further subjected to heat exchange with the superheated steam with a higher temperature in the first heat exchanger 102, to obtain molten salt with a higher temperature, and is input into the high-temperature molten salt tank 105 for storage.

[0042] In actual application, in order to control the temperature of the high-temperature molten salt input into the high-temperature molten salt tank 105, so that the temperature of the high-temperature molten salt meets a preset condition, and in order to ensure the safety of the heat exchange process, the thermal power generating unit coupled with the molten salt energy storage system can further include a temperature and pressure reducing device, which is arranged on the steam output pipeline 101 of the thermal power generating unit. Specifically, the temperature and pressure reducing device can include a pressure reducing valve 109 and a desuperheating water pipeline 110, an outlet of the desuperheating water pipeline 110 is in communication with a first position A of the steam output pipeline 101 of the thermal power generating unit, the pressure reducing valve 109 is located downstream of the first position A, and the manual adjusting valve 106 and the electric adjusting valve 107 are located upstream of the first position A. By arranging the desuperheating water pipeline 110, the high-temperature and high-pressure steam can be cooled to a certain extent, and by arranging the pressure reducing valve 109, the pressure of the high-temperature and high-pressure steam can be reduced to a certain extent. In this way, the pressure of the high-temperature and high-pressure steam entering the first heat exchanger 102 is not too high, which affects the safety; and after the heat exchange in the first heat exchanger 102, the temperature of the high-temperature molten salt output by the first heat exchanger 102 is not too high.

[0043] Further, the thermal power unit coupled molten salt energy storage system can further comprise a low-temperature molten salt pump 111 and a high-temperature molten salt pump 112. The low-temperature molten salt pump 111 is arranged on a pipe through which the low-temperature molten salt tank 104 outputs the low-temperature molten salt to the second heat exchanger 103, and the high-temperature molten salt pump 112 is arranged on a molten salt output pipe of the high-temperature molten salt tank 105. When the molten salt needs to be used for heat absorption and energy storage, the low-temperature molten salt pump 111 is started to pump the low-temperature molten salt into the second heat exchanger 103. When the molten salt needs to be used for heat release, the high-temperature molten salt pump 112 is started to pump the high-temperature molten salt to the corresponding heat release system. The low-temperature molten salt obtained by cooling the high-temperature molten salt after heat release can be stored in the low-temperature molten salt tank 104 from the low-temperature molten salt input pipe 113. In a specific implementation, two low-temperature molten salt pumps 111 can be arranged in parallel on the pipe through which the low-temperature molten salt tank 104 outputs the low-temperature molten salt to the second heat exchanger 103, and frequency conversion adjustment can be performed. Similarly, two high-temperature molten salt pumps 112 can be arranged in parallel on the molten salt output pipe of the high-temperature molten salt tank 105, and frequency conversion adjustment can be performed.

[0044] It can be understood that the thermal power unit coupled molten salt energy storage system provided by the above-mentioned embodiments of the present application comprises a thermal power unit steam output pipe 101, a first heat exchanger 102, a second heat exchanger 103, a low-temperature molten salt tank 104, and a high-temperature molten salt tank 105. The outlet of the thermal power unit steam output pipe 101 is in communication with the steam inlet of the first heat exchanger 102, the steam outlet of the first heat exchanger 102 is in communication with the steam inlet of the second heat exchanger 103, the outlet of the low-temperature molten salt tank 104 is in communication with the molten salt inlet of the second heat exchanger 103, the molten salt outlet of the second heat exchanger 103 is in communication with the molten salt inlet of the first heat exchanger 102, and the molten salt outlet of the first heat exchanger 102 is in communication with the inlet of the high-temperature molten salt tank 105. By arranging the first heat exchanger 102 and the second heat exchanger 103, the heat energy of the high-temperature and high-pressure steam can be progressively utilized, so that the temperature difference of the heat transfer in the heat exchange process can be reduced, thereby the heat loss of the heat transfer process can be reduced, and the utilization rate of the heat energy of the high-temperature and high-pressure steam can be improved.

[0045] On the other hand, in the heat exchange process, the temperature difference of the heat transfer is small, and the temperature variation range of the material of the heat exchanger can also be reduced, so that the operation safety of the heat exchanger can be improved.

[0046] In an embodiment of the present application, a monitoring system is also provided to monitor the operation of the thermal power unit coupled with the molten salt energy storage system provided in the above embodiments. The monitoring system can include a controller (not shown in the figure, which can be similar to the data-driven control strategy database) and an operation performance detection device and a safety performance detection device arranged in the thermal power unit coupled with the molten salt energy storage system, both of which are connected to the controller. The operation performance detection device can detect parameters related to the operation performance of the thermal power unit coupled with the molten salt energy storage system, and the safety performance detection device can detect parameters related to the safety performance of the thermal power unit coupled with the molten salt energy storage system. The controller is connected to the operation performance detection device and the safety performance detection device, and can obtain in real time the parameters related to the operation performance of the thermal power unit coupled with the molten salt energy storage system and the parameters related to the safety performance of the thermal power unit coupled with the molten salt energy storage system, and then perform some related regulation and control on the thermal power unit coupled with the molten salt energy storage system.

[0047] As shown in Figure 1 In the embodiments of the present application, the operation performance detection device can include a first temperature detection device 201, a second temperature detection device 202, a third temperature detection device 203, a fourth temperature detection device 204, a fifth temperature detection device 205, and a sixth temperature detection device 206. The first temperature detection device 201 is arranged on the steam output pipeline 101 of the thermal power unit, the second temperature detection device 202 is arranged on a pipeline for connecting the steam outlet of the first heat exchanger 102 and the steam inlet of the second heat exchanger 103, the third temperature detection device 203 is arranged on the condensate output pipeline 108, the fourth temperature detection device 204 is arranged on a pipeline for connecting the outlet of the low-temperature molten salt tank 104 and the molten salt inlet of the second heat exchanger 103, the fifth temperature detection device 205 is arranged on a pipeline for connecting the molten salt outlet of the second heat exchanger 103 and the molten salt inlet of the first heat exchanger 102, and the sixth temperature detection device 206 is arranged on a pipeline for connecting the molten salt outlet of the first heat exchanger 102 and the inlet of the high-temperature molten salt tank 105.

[0048] The first temperature detection device 201 is arranged on the steam output pipeline 101 of the thermal power unit, and can be arranged at a position close to the steam inlet of the first heat exchanger 102 to detect the steam temperature at the steam inlet of the first heat exchanger 102.

[0049] To reduce the heat loss of steam, the pipeline for connecting the steam outlet of the first heat exchanger 102 and the steam inlet of the second heat exchanger 103 is generally short, and the second temperature detection device 202 is arranged on the pipeline to detect the steam temperature at the steam outlet of the first heat exchanger 102 and the steam temperature at the steam inlet of the second heat exchanger 103.

[0050] The third temperature detecting device 203 is arranged on the condensate water output pipeline 108, and can be arranged near the condensate water outlet of the second heat exchanger 103, for detecting the condensate water temperature of the condensate water outlet of the second heat exchanger 103.

[0051] The fourth temperature detecting device 204 is arranged on the pipeline for connecting the outlet of the low-temperature molten salt tank 104 and the molten salt inlet of the second heat exchanger 103, and can be arranged near the molten salt inlet of the second heat exchanger 103, for detecting the molten salt temperature of the molten salt inlet of the second heat exchanger 103.

[0052] In order to reduce the steam heat loss, the pipeline for connecting the molten salt outlet of the second heat exchanger 103 and the molten salt inlet of the first heat exchanger 102 is generally short, and the fifth temperature detecting device 205 is arranged on the pipeline, which can detect the molten salt temperature of the molten salt outlet of the second heat exchanger 103 and the molten salt temperature of the molten salt inlet of the first heat exchanger 102.

[0053] The sixth temperature detecting device 206 is arranged on the pipeline for connecting the molten salt outlet of the first heat exchanger 102 and the inlet of the high-temperature molten salt tank 105, and can be arranged near the molten salt outlet of the first heat exchanger 102, for detecting the molten salt temperature of the molten salt outlet of the first heat exchanger 102.

[0054] In an embodiment, the operation performance detecting device can further include a first pressure detecting device 207 and a second pressure detecting device 208, the first pressure detecting device 207 is arranged on the steam output pipeline 101 of the thermal power generating unit, and the second pressure detecting device 208 is arranged on the condensate water output pipeline 108.

[0055] The first pressure detecting device 207 is arranged on the steam output pipeline 101 of the thermal power generating unit, and can be arranged near the steam inlet of the first heat exchanger 102, for detecting the steam pressure of the steam inlet of the first heat exchanger 102.

[0056] The second pressure detecting device 208 is arranged on the condensate water output pipeline 108, and can be arranged near the condensate water outlet of the second heat exchanger 103, for detecting the condensate water pressure of the condensate water outlet of the second heat exchanger 103.

[0057] Further, the operation performance detecting device can further include a flow detecting device 209, which is arranged on the condensate water output pipeline 108, and can be a standard flow orifice plate.

[0058] In actual application, the controller can also be connected with the low-temperature molten salt pump 111 and the high-temperature molten salt pump 112 to obtain the operating current of the low-temperature molten salt pump 111 and the operating current of the high-temperature molten salt pump 112. The operating current of the low-temperature molten salt pump 111 and the operating current of the high-temperature molten salt pump 112 can also be regarded as parameters related to the operating performance of the thermal power unit coupled molten salt energy storage system. The operating currents of the low-temperature molten salt pump 111 and the high-temperature molten salt pump 112 can be used to represent the operating flow and resistance of the system.

[0059] In the embodiment of the present application, the safety performance detection device can include a first stress detection device 210, a second stress detection device 211, a third stress detection device 212, and a fourth stress detection device 213. The first stress detection device 210 is arranged at the steam inlet of the first heat exchanger 102, the second stress detection device 211 is arranged at the molten salt outlet of the first heat exchanger 102, the third stress detection device 212 is arranged at the steam inlet of the second heat exchanger 103, and the fourth stress detection device 213 is arranged at the molten salt outlet of the first heat exchanger 103.

[0060] Since the thermal power unit coupled molten salt energy storage system is frequently started and stopped, and the working conditions of the first heat exchanger 102 and the second heat exchanger 103 change greatly, the reliability of the first heat exchanger 102 and the second heat exchanger 103 is required to be high. By arranging the corresponding stress detection devices at the steam inlet of the first heat exchanger 102, the molten salt outlet of the first heat exchanger 102, the steam inlet of the second heat exchanger 103, and the molten salt outlet of the first heat exchanger 103 which are frequently subjected to fatigue-creep, the safety and reliability of the first heat exchanger 102 and the second heat exchanger 103 can be monitored.

[0061] In specific implementation, each stress detection device can include two sub stress detection devices, and the two sub stress detection devices are arranged at 90° along the inlet or outlet. Taking the two sub stress detection devices included in the first stress detection device 210 as an example, the sub stress detection device B and the sub stress detection device C can be arranged at 90° at the pipe opening of the steam inlet of the first heat exchanger 102, that is, the line connecting the sub stress detection device B and the center of the pipe section and the line connecting the sub stress detection device C and the center of the pipe section form a 90° angle. Therefore, based on the stress values detected by the sub stress detection device B and the sub stress detection device C, the stress condition of the high-temperature steam heat transfer pipe side of the first heat exchanger 102 can be more accurately judged. When the remaining stress detection devices include two sub stress detection devices, the arrangement positions of the two sub stress detection devices can refer to the arrangement positions of the sub stress detection device B and the sub stress detection device C, which will not be described here.

[0062] In an embodiment, the safety performance detection device further comprises a fifth stress detection device 214 and a sixth stress detection device 215; the fifth stress detection device 214 is arranged on the high-temperature molten salt tank 105 and is used to detect the stress of the typical position of the weld of the tank body of the high-temperature molten salt tank 105; the sixth stress detection device 215 is arranged on the low-temperature molten salt tank 104 and is used to detect the stress of the typical position of the weld of the tank body of the low-temperature molten salt tank 104.

[0063] Further, the safety performance detection device further comprises a high-temperature molten salt sampling port 216 and a low-temperature molten salt sampling port 217. The low-temperature molten salt tank 104 and the high-temperature molten salt tank 105 are in a situation of alternating cold and heat for a long time during the operation of the system, which is easy to cause the instability of the properties of the molten salt. Especially, if water is analyzed out, it will cause adverse effects on the safety of the operation of the system. By arranging the high-temperature molten salt sampling port 216 and the low-temperature molten salt sampling port 217, the sampling of the molten salt can be carried out regularly, and the change of the properties of the molten salt can be obtained.

[0064] The safety performance detection device further comprises a first optical fiber type liquid level monitoring device 218 and a second optical fiber type liquid level monitoring device 219; the first optical fiber type liquid level monitoring device 218 is arranged in the high-temperature molten salt tank 105, and the second optical fiber type liquid level monitoring device 219 is arranged in the low-temperature molten salt tank 104. The first optical fiber type liquid level monitoring device 218 and the second optical fiber type liquid level monitoring device 219 have high corrosion resistance and high sensitivity. In addition, the first optical fiber type liquid level monitoring device 218 and the second optical fiber type liquid level monitoring device 219 further have an optical fiber temperature layer, which can obtain the temperature of the molten salt. By the distribution of the temperature of the molten salt in the tank and the uniformity of the temperature, the flow state of the molten salt in the tank can be determined, and the solidification of the molten salt can be prevented.

[0065] In actual application, the safety performance detection device further comprises some devices capable of measuring the thickness of the tank body and the pipeline, so as to obtain the corrosion condition of the tank body and the pipeline.

[0066] In an embodiment of the present application, a regulation method is also provided. The regulation method can regulate the operation of the thermal power unit coupled molten salt energy storage system by using the conditions monitored by the monitoring system provided in the above embodiments. As shown in the figure, the regulation method can comprise the following steps: Figure 2

[0067] Step 301: determining the operation state of the thermal power unit coupled molten salt energy storage system based on the target parameters monitored by the monitoring system.

[0068] The target parameters can comprise the parameters related to the operation performance of the thermal power unit coupled molten salt energy storage system and the parameters related to the safety performance of the thermal power unit coupled molten salt energy storage system.

[0069] ​So, step 301 can specifically include steps one, two and three, specifically as follows:

[0070] Step one, based on the parameters in the target parameters related to the operation performance of the thermal power unit coupled with the molten salt energy storage system, determine the first running state of the thermal power unit coupled with the molten salt energy storage system.

[0071] In actual application, the upper end temperature difference of the first heat exchanger, the lower end temperature difference of the first heat exchanger, and the lower end temperature difference of the second heat exchanger can be calculated first, and then based on the upper end temperature difference of the first heat exchanger, the lower end temperature difference of the first heat exchanger, the lower end temperature difference of the second heat exchanger, the flow, the operating current of the low-temperature molten salt pump and the operating current of the high-temperature molten salt pump and other parameters related to the operation performance of the thermal power unit coupled with the molten salt energy storage system, the first running state of the thermal power unit coupled with the molten salt energy storage system is determined. Wherein, the upper end temperature difference of the first heat exchanger is the steam temperature of the steam inlet of the first heat exchanger minus the molten salt temperature of the molten salt outlet of the first heat exchanger; the lower end temperature difference of the first heat exchanger is the steam temperature of the steam outlet of the first heat exchanger minus the molten salt temperature of the molten salt inlet of the first heat exchanger; the lower end temperature difference of the second heat exchanger is the condensate water temperature of the condensate water outlet of the second heat exchanger minus the molten salt temperature of the molten salt inlet of the second heat exchanger.

[0072] Specifically, the first running state of the thermal power unit coupled with the molten salt energy storage system can be determined as normal state, abnormal state or dangerous state by comparing the parameter size of the typical working condition.

[0073] For example: the upper end temperature difference or the lower end temperature difference of the heat exchanger can be compared with the design reference value, when the deviation ratio between the two is ≤30%, the first running state of the system can be determined as normal state. When the deviation ratio between the two is greater than 30% and less than 80%, the first running state of the system can be determined as abnormal state. When the deviation ratio between the two is ≥80%, the first running state of the system can be determined as dangerous state. It should be understood that the deviation ratio threshold values of 30% and 80% are only specific examples, and do not represent improper limitation of the present application. The specific value of the deviation ratio threshold can be dynamically set according to the equipment, system operation, etc.

[0074] Step two, based on the parameters in the target parameters related to the safety performance of the thermal power unit coupled with the molten salt energy storage system, determine the second running state of the thermal power unit coupled with the molten salt energy storage system.

[0075] In specific implementation, the design allowable stress value of various parts can be compared to determine whether the second running state of the thermal power unit coupled with the molten salt energy storage system is normal state, abnormal state or dangerous state.

[0076] For example, the stress value detected at a certain part can be compared with the design allowable stress value of the part, when the deviation ratio between the two is less than or equal to 110%, it can be determined that the second operating state of the system is a normal state. When the deviation ratio between the two is greater than 110% and less than 160%, it can be determined that the second operating state of the system is an abnormal state. When the deviation ratio between the two is greater than or equal to 160%, it can be determined that the second operating state of the system is a dangerous state.

[0077] Step three, determining a target operating state from the first operating state and the second operating state.

[0078] In specific implementation, priority can be set for the parameters related to the operating performance of the molten salt energy storage system coupled with the thermal power generating unit and the parameters related to the safety performance of the molten salt energy storage system coupled with the thermal power generating unit, when the first operating state and the second operating state are different, the operating state corresponding to the parameter with higher priority is taken as the target operating state, that is, the operating state of the molten salt energy storage system coupled with the thermal power generating unit. When the first operating state and the second operating state are the same, either of the first operating state and the second operating state can be taken as the target operating state.

[0079] Step 302, determining a control strategy according to the operating state and the preset index, and controlling the operation of the molten salt energy storage system coupled with the thermal power generating unit based on the control strategy.

[0080] The preset index can include a safety index and an economic index.

[0081] In actual application, the control strategy as a whole follows the principle of "safety first", that is, on the basis of ensuring that the safety value index of the key equipment of the system is controllable, the system scheduling and optimization adjustment are carried out.

[0082] For example, when the system is in a small flow working condition or a large load working condition, if the end temperature difference of the heat exchanger has deviated from the design normal allowable value range, and the system operating state is determined to be an abnormal state, timely adjustment of the operating condition can be carried out to avoid frequent over-limit operation and make the system return to normal state operation. When the system operating state is determined to be a dangerous state, the system can be arranged to stop running, and detection, inspection and elimination of unsafe factors can be arranged.

[0083] It can be understood that by using the control method provided in the above embodiments of the present application, the operating state of the molten salt energy storage system coupled with the thermal power generating unit is determined based on the target parameters monitored by the monitoring system, the control strategy is determined according to the operating state and the preset index, and the operation of the molten salt energy storage system coupled with the thermal power generating unit is controlled based on the control strategy, so that the safety and reliability and the economy of the operation of the molten salt energy storage system coupled with the thermal power generating unit can be ensured.

[0084] Those skilled in the art will appreciate that embodiments of the application can be readily used as software, hardware, or a combination of software and hardware. In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0085] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0086] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0087] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0088] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0089] The memory can include non-persistent memory and / or persistent memory, such as flash memory, read-only memory (ROM), and / or volatile or non-volatile random access memory (RAM), among others. The memory is an example of computer-readable media.

[0090] Computer-readable media includes permanent and non-permanent, movable and non-movable media, which can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible by a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.

[0091] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusions, so that processes, methods, articles or devices that include a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0092] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the scope of claims of the present application.

Claims

1. A control method, characterized in that, The control method is used to control the thermal power unit coupled with the molten salt energy storage system based on the monitoring system; the thermal power unit coupled with the molten salt energy storage system includes a thermal power unit steam output pipeline, a first heat exchanger, a second heat exchanger, a low-temperature molten salt tank, a high-temperature molten salt tank, and a condensate output pipeline; The outlet of the steam output pipeline of the thermal power unit is connected to the steam inlet of the first heat exchanger, the steam outlet of the first heat exchanger is connected to the steam inlet of the second heat exchanger, and the inlet of the condensate output pipeline is connected to the condensate outlet of the second heat exchanger. The outlet of the low-temperature molten salt tank is connected to the molten salt inlet of the second heat exchanger, the molten salt outlet of the second heat exchanger is connected to the molten salt inlet of the first heat exchanger, and the molten salt outlet of the first heat exchanger is connected to the inlet of the high-temperature molten salt tank. The monitoring system includes a controller and an operational performance testing device and a safety performance testing device installed in the coupled molten salt energy storage system of the thermal power unit. Both the operational performance testing device and the safety performance testing device are connected to the controller. The operational performance testing device includes a first temperature detection device, a second temperature detection device, a third temperature detection device, a fourth temperature detection device, a fifth temperature detection device, and a sixth temperature detection device. The first temperature detection device is installed on the steam output pipeline of the thermal power unit; the second temperature detection device is installed on the pipeline connecting the steam outlet of the first heat exchanger and the steam inlet of the second heat exchanger; the third temperature detection device is installed on the condensate output pipeline; the fourth temperature detection device is installed on the pipeline connecting the outlet of the low-temperature molten salt tank and the molten salt inlet of the second heat exchanger; the fifth temperature detection device is installed on the pipeline connecting the molten salt outlet of the second heat exchanger and the molten salt inlet of the first heat exchanger; and the sixth temperature detection device is installed on the pipeline connecting the molten salt outlet of the first heat exchanger and the inlet of the high-temperature molten salt tank. The temperatures detected by the first temperature detection device and the sixth temperature detection device are used to calculate the temperature difference between the steam inlet and the molten salt outlet of the first heat exchanger; the temperatures detected by the second temperature detection device and the fifth temperature detection device are used to calculate the temperature difference between the steam outlet and the molten salt inlet of the first heat exchanger; and the temperatures detected by the third temperature detection device and the fourth temperature detection device are used to calculate the temperature difference between the condensate outlet and the molten salt inlet of the second heat exchanger. The safety performance testing device includes a first stress testing device, a second stress testing device, a third stress testing device, and a fourth stress testing device. The first stress detection device is installed at the steam inlet of the first heat exchanger, the second stress detection device is installed at the molten salt outlet of the first heat exchanger, the third stress detection device is installed at the steam inlet of the second heat exchanger, and the fourth stress detection device is installed at the molten salt outlet of the second heat exchanger. In the first stress detection device, the second stress detection device, the third stress detection device and the fourth stress detection device, each stress detection device includes two sub-stress detection devices, and the two sub-stress detection devices are arranged at 90° along the inlet or outlet. The control method includes: The temperature difference at the upper end of the first heat exchanger, the temperature difference at the lower end of the first heat exchanger, and the temperature difference at the lower end of the second heat exchanger are compared with their respective design reference values. If the deviation ratio between the upper or lower temperature difference of any of the first or second heat exchangers and the corresponding design reference value is ≤30%, the first operating state of the thermal power unit coupled with molten salt energy storage system is determined to be a normal state. If the deviation ratio between the upper or lower temperature difference of any heat exchanger and the corresponding design reference value is greater than 30% but less than 80%, the first operating state of the thermal power unit coupled with molten salt energy storage system is determined to be an abnormal state. If the deviation ratio between the upper or lower temperature difference of any heat exchanger and the corresponding design reference value is ≥80%, the first operating state of the thermal power unit coupled with molten salt energy storage system is determined to be a dangerous state. The stress values ​​detected at the steam inlet, molten salt outlet, steam inlet, and molten salt outlet of the first heat exchanger, the second heat exchanger, and the second heat exchanger are compared with their respective design allowable stress values. If the deviation ratio between the stress value detected at any of these locations and the corresponding design allowable stress value is ≤110%, the second operating state of the thermal power unit coupled with the molten salt energy storage system is determined to be a normal state. If the deviation ratio between the stress value detected at any location and the corresponding design allowable stress value is greater than 110% and less than 160%, the second operating state of the thermal power unit coupled with the molten salt energy storage system is determined to be an abnormal state. If the deviation ratio between the stress value detected at any location and the corresponding design allowable stress value is ≥160%, the second operating state of the thermal power unit coupled with the molten salt energy storage system is determined to be a dangerous state. Based on the priority of the deviation between the temperature difference and the design reference value and the deviation between the stress value and the design allowable stress value, a target operating state is determined from the first operating state and the second operating state as the operating state of the thermal power unit coupled molten salt energy storage system. Based on the operating status and preset indicators, a control strategy is determined, and the operation of the thermal power unit coupled with the molten salt energy storage system is controlled based on the control strategy.

2. The control method according to claim 1, characterized in that, The thermal power unit coupled molten salt energy storage system also includes a desuperheating and pressure reducing device, which is installed on the steam output pipeline of the thermal power unit.

3. The control method according to claim 1, characterized in that, The performance testing device also includes a flow detection device, which is installed on the condensate output pipeline.

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