Thermal power generation system coupled with fused salt energy storage peak operation

Abstract

The utility model discloses a thermal power generation system coupled with fused salt energy storage peak operation, which comprises a combustion boiler for generating high-temperature and high-pressure main steam; after the main steam enters the steam turbine high-pressure cylinder to do work, the main steam returns to the combustion boiler to be reheated for the first time so as to form reheated steam for the first time; the primary reheat steam enters the molten salt energy storage system to supply heat to the molten salt energy storage system, and after the primary reheat steam stores energy, the primary reheat steam returns to the combustion boiler to be subjected to secondary reheat, so that secondary reheat steam is formed; the secondary reheat steam enters the steam turbine intermediate-pressure cylinder to do work and then enters the steam turbine low-pressure cylinder to do work continuously, and the steam turbine high-pressure cylinder, the steam turbine intermediate-pressure cylinder and the steam turbine low-pressure cylinder coaxially drive a main steam turbine generator unit to generate power; the secondary reheat steam is exhausted through a low-pressure cylinder of the steam turbine and then enters the condenser to form condensed water, and then the condensed water enters the combustion boiler.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal power generation and molten salt energy storage, and in particular to a thermal power generation system coupled with molten salt energy storage peak operation. Background Art

[0002] With the rapid development of new energy, in the emerging power system, thermal power generating units have the functions of flexible operation and peak operation, and their basic security and system regulation needs are prominent. For example, in the photovoltaic power generation base, the photovoltaic generating units operate at high power during the day, and the guaranteed power supply is missing at night. However, due to technical and economic constraints, the cost and safety of the existing large-scale energy storage system cannot meet the demand. Thermal power plants have good peak-shaving capabilities, and how to further increase their peak functions is a major technical problem and practical need currently faced.

[0003] To this end, many units have carried out research on the "extracted steam energy storage" system. The design of the "extracted steam energy storage" system has put forward higher requirements on the original steam turbine generator set. There are technical problems that are difficult to solve in the matching of the extraction steam (main steam) with the molten salt heat exchanger and the original steam turbine generator set system, mainly including temperature matching, pressure matching and a significant increase in cold end losses. Utility Model Content

[0004] The purpose of the utility model is to propose a thermal power generation system coupled with molten salt energy storage peak operation to solve the problems existing in the existing "extracted steam storage" system.

[0005] In order to achieve the above object, the utility model is realized by the following technical solutions:

[0006] The utility model designs a thermal power generation system coupled with molten salt energy storage peak operation, and the thermal power generation system comprises:

[0007] combustion boilers, which generate high-temperature, high-pressure main steam;

[0008] The main steam enters the high-pressure cylinder of the steam turbine to perform work, and then returns to the combustion boiler for reheating to form primary reheat steam;

[0009] Molten salt energy storage system, the primary reheated steam enters the molten salt energy storage system to provide heat for the molten salt energy storage system and store energy, and then returns to the combustion boiler for secondary reheating to form secondary reheated steam;

[0010] The secondary reheated steam enters the intermediate pressure cylinder of the steam turbine to perform work and then enters the low pressure cylinder of the steam turbine to continue to perform work. The high pressure cylinder of the steam turbine, the intermediate pressure cylinder of the steam turbine and the low pressure cylinder of the steam turbine coaxially drive the main steam turbine generator set to generate electricity;

[0011] And a condenser, the secondary reheated steam enters the condenser after being exhausted from the low-pressure cylinder of the steam turbine to form condensed water, and then enters the combustion boiler.

[0012] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: a main steam valve is provided at the inlet of the high-pressure cylinder of the steam turbine.

[0013] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: the molten salt energy storage system comprises the following:

[0014] A steam molten salt heat exchanger, wherein the primary reheated steam enters the steam molten salt heat exchanger as a heat source to provide heat for the steam molten salt heat exchanger, and then returns to the combustion boiler to be heated again to form secondary reheated steam;

[0015] A cold molten salt tank, in which cold molten salt is stored. The cold molten salt is heated and stored in the steam molten salt heat exchanger to become hot molten salt and enter the hot molten salt tank for storage;

[0016] The hot molten salt stored in the hot molten salt tank is used as a heat source to enter the steam generator and the steam turbine generator set to provide heat for them, so that they generate steam and drive the steam turbine generator to generate electricity. After providing heat, the hot molten salt becomes cold molten salt and enters the cold molten salt tank.

[0017] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: the molten salt energy storage system also includes a cold molten salt pump and a hot molten salt pump; the cold molten salt pump is used to pump the cold molten salt into the steam molten salt heat exchanger for heating and energy storage and into the hot molten salt tank for storage; the hot molten salt pump is used to pump the hot molten salt into the steam generator and steam turbine generator set to provide heat and release energy for them and into the cold molten salt tank.

[0018] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: the thermal power generation system also includes a bypass valve; the bypass valve is arranged in parallel with the steam molten salt heat exchanger to divert the primary reheat steam entering the steam molten salt heat exchanger.

[0019] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: the low-pressure cylinder of the steam turbine is arranged in two groups and arranged in parallel.

[0020] Furthermore, a thermal power generation system coupled with molten salt energy storage peak operation: the thermal power generation system also includes a condensate pump and a feed water heat recovery system; the condensate formed in the condenser is pumped into the feed water heat recovery system through the condensate pump, and then enters the combustion boiler through the high-pressure feed water of the feed water heat recovery system.

[0021] The purpose of the thermal power generation system coupled with molten salt energy storage peak operation designed by the utility model is to meet the requirements of future coal-fired power peak operation. The utility model uses the molten salt energy storage system to extract part of the energy when the combustion boiler unit is running and send it to the molten salt energy storage system for storage. When peak operation is required, the molten salt energy storage system is equipped with a steam generator (SGS) and an independent steam turbine generator set to increase the power plant's peak power generation capacity. The utility model uses the basic principle of a single reheat steam turbine unit (such as Figure 1 As shown), boilers with secondary reheat (such as Figure 2 As shown), that is, another reheat system is set between the primary intermediate reheat and the main steam system, and the absorbed heat is used to heat the molten salt, and the energy is stored in the molten salt system; when peak operation is required, the high-temperature molten salt is used to heat the steam-water medium to generate high-temperature, high-pressure steam, which drives the peak-operation steam turbine generator set to realize the peak operation function of the power plant.

[0022] Explanation of terminology: A steam turbine generator set refers to a generator driven by a steam turbine. The superheated steam generated by the boiler enters the steam turbine and expands to do work, causing the blades to rotate, thereby driving the generator to generate electricity. The waste steam after work is sent back to the boiler for recycling through the condenser, circulating water pump, condensate pump, feed water heating device, etc.

[0023] Beneficial effects of the utility model:

[0024] The thermal power generation system coupled with molten salt energy storage peak operation designed by the utility model utilizes the principle of the molten salt energy storage system. The original steam turbine generator set and the thermal system are not changed, only the boiler system is changed. The current secondary reheat boiler principle is utilized, and the added reheat system is used to heat the molten salt energy storage system and store energy. The steam pressure and temperature at the inlet of the steam molten salt heat exchanger can be fully matched, there is no temperature reduction or pressure reduction loss, and there is no need to increase the cold end loss of the steam turbine generator set, which has obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is the principle flow chart of the existing single reheat steam turbine unit system;

[0027] Figure 2 It is the principle flow chart of the existing double reheat steam turbine unit system;

[0028] Figure 3This is the principle flow chart of the existing "extracted steam storage" system;

[0029] Figure 4 A principle flow chart of a thermal power generation system coupled with molten salt energy storage peak operation designed for Example 1 of the utility model.

[0030] The following are marked in the figure:

[0031] 1-combustion boiler, 2-steam turbine high-pressure cylinder, 3-steam molten salt heat exchanger, 4-cold molten salt tank, 5-hot molten salt tank, 6-steam generator and steam turbine generator set, 7-cold molten salt pump, 8-hot molten salt pump, 9-bypass valve, 10-steam turbine intermediate-pressure cylinder, 11-steam turbine low-pressure cylinder, 12-main steam turbine generator set, 13-condenser, 14-main steam valve, 15-condensate pump, 16-feedwater heat recovery system, 17-primary reheater, 18-secondary reheater, 19-steam turbine ultra-high-pressure cylinder. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] In the description of the present utility model, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom" and the like indicate positions or positional relationships, which are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Moreover, the terms "first", "second" and the like are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein.

[0034] like Figure 1As shown, it shows a principle flow chart of an existing single-reheat steam turbine unit system. A single-reheat steam turbine refers to sending the medium-temperature steam discharged from the high-pressure cylinder 2 of the steam turbine to the boiler for reheating once and then sending it to the intermediate-pressure cylinder 10 of the steam turbine. The exhaust steam of the intermediate-pressure cylinder 10 of the steam turbine enters the low-pressure cylinder 11 of the steam turbine to do work and then is discharged into the condenser.

[0035] like Figure 2 As shown, it shows a principle flow chart of an existing secondary reheat steam turbine unit system. The secondary reheat power generation technology is currently an effective way to improve the thermal efficiency of thermal power units. After the main steam enters the ultra-high pressure cylinder 19 to do work, it is sent to the boiler's primary reheat system for heating, and then enters the high pressure cylinder 2 to do work. The high pressure cylinder exhaust steam is sent back to the boiler's secondary reheat system for heating, enters the medium pressure cylinder 10 to do work, and finally enters the low pressure cylinder 11 to do work and then is discharged into the condenser. The secondary reheat unit can reduce the coal consumption for power supply compared to the single reheat unit.

[0036] Example 1

[0037] like Figure 4 As shown, this embodiment 1 designs a thermal power generation system coupled with molten salt energy storage peak operation, the system comprising:

[0038] A combustion boiler 1, which generates high-temperature, high-pressure main steam;

[0039] The main steam enters the high-pressure cylinder 2 of the steam turbine, expands and does work, and then returns to the combustion boiler 1 to be reheated once through the primary reheater 17 to form primary reheated steam. A main steam valve 14 is provided at the inlet of the high-pressure cylinder 2 of the steam turbine;

[0040] The steam molten salt heat exchanger 3, the primary reheated steam enters the steam molten salt heat exchanger 3 as a heat source to provide heat for the steam molten salt heat exchanger 3, and then returns to the combustion boiler 1 to be reheated for the second time through the secondary reheater 18 to form secondary reheated steam;

[0041] The cold molten salt tank 4 stores cold molten salt, which is pumped into the steam molten salt heat exchanger 3 by the cold molten salt pump 7 for heating and energy storage to become hot molten salt and then enter the hot molten salt tank 5 for storage;

[0042] The steam generator and steam turbine generator set 6 use the hot molten salt stored in the hot molten salt tank 5 as a heat source and pump it into the steam generator (SGS) and steam turbine generator set 6 through the hot molten salt pump 8 to provide heat for them, so that the steam-water medium is heated to generate high-temperature, high-pressure steam and drive the independent steam turbine generator set 6 to generate electricity. After the hot molten salt provides heat for the steam generator and steam turbine generator set 6, it becomes cold molten salt and enters the cold molten salt tank 4;

[0043] A bypass valve 9, which is arranged in parallel with the steam molten salt heat exchanger 3 and is used to divert the primary reheat steam entering the steam molten salt heat exchanger 3;

[0044] The secondary reheated steam enters the steam turbine intermediate pressure cylinder 10, expands and performs work, and then enters two sets of steam turbine low pressure cylinders 11 arranged in parallel to continue to expand and perform work. The steam turbine high pressure cylinder 2, the steam turbine intermediate pressure cylinder 10 and the steam turbine low pressure cylinder 11 coaxially drive the main steam turbine generator set 11 to generate electricity;

[0045] And the condenser 13, the secondary reheated steam enters the condenser 13 after being exhausted by the two sets of turbine low-pressure cylinders 11 to form condensed water, and then the condensed water is pumped into the feed water heat recovery system 16 through the condensate pump 15, and finally enters the combustion boiler 1 through the feed water heat recovery system 16 high-pressure feed water for recycling.

[0046] The above-mentioned steam molten salt heat exchanger 3, cold molten salt tank 4, hot molten salt tank 5, steam generator and steam turbine generator set 6 constitute a molten salt energy storage system, which uses primary reheated steam to heat the system and store energy, and stores energy in the molten salt system; when peak operation is required, high-temperature hot molten salt is used to heat the steam-water medium to generate high-temperature and high-pressure steam, which drives the independent steam turbine generator set for peak operation, thereby realizing the peak operation function of the power plant.

[0047] The thermal power generation system coupled with molten salt energy storage peak operation designed in the above-mentioned embodiment 1 is provided with a molten salt energy storage system and an independent steam turbine generator set 6 of the molten salt energy storage system on the basis of the original thermal power generation unit, which can realize the peak operation function of the unit. In this embodiment 1, the pressure of the main steam system increases, and the increase value matches the increase in the loss of the reheat system, the molten salt steam heat exchanger and its pipeline system, and the inlet and outlet pressure of the high-pressure cylinder or ultra-high-pressure cylinder of the corresponding steam turbine generator set increases. In this embodiment 1, the exhaust steam of the high-pressure cylinder 2 of the steam turbine is not sent to the medium-pressure cylinder 10 of the steam turbine to do work after being heated by the combustion boiler 1, but is first used to heat the molten salt energy storage system, and the primary reheated steam after the molten salt energy storage system releases energy (cooling) is sent to the combustion boiler 1 for continued reheating (secondary reheater), and the secondary reheated steam after reheating is sent to the medium-pressure cylinder 10 of the steam turbine to do work. In this embodiment 1, the steam molten salt heat exchanger 3, the newly added boiler secondary reheater 18, and the turbine intermediate pressure cylinder 10 are a series system, and the primary reheated steam can also be partially bypassed through the bypass valve 9 to adjust the heat absorption of the molten salt heat exchanger 3, or to increase the steam inlet temperature of the turbine low-pressure cylinder 11 under low-load conditions to improve the unit efficiency. The steam generated by the molten salt energy storage system in this embodiment 1 can also be supplied as industrial steam. The molten salt in this embodiment 1 can be solar salt (40% potassium nitrate + 60% sodium nitrate) or other molten salts.

[0048] like Figure 3As shown in the prior art "Study on Deep Peak Shaving Technology of Steam Extraction Energy Storage in Thermal Power Plants" proposes a steam extraction energy storage system design, which adopts a structural design of extracting main steam and high-temperature reheated steam at the same time, and only uses their sensible heat to heat the molten salt. After the pressure drops, they are respectively merged into the high-pressure cylinder exhaust steam and the medium-pressure cylinder exhaust steam, and returned to the original thermal system. The principle of this system is as follows Figure 3 shown.

[0049] However, in Figure 3 In the design shown, there is a large pressure difference between the main steam pressure and the high-pressure cylinder exhaust pressure. The main steam pressure is about 29.3MPa, and the high-pressure cylinder exhaust pressure is only about 6.178MPa. This system design has a huge pressure drop loss during the heating process, that is, Loss (useful work capacity loss), generally the medium pressure cylinder pressure is about 0.5MPa, from the high temperature reheat steam (pressure 5.978MPa), back to the middle row there is also a large pressure loss ( At the same time, this method of directly extracting main steam (main steam temperature is about 605℃) to heat the molten salt energy storage system, because the temperature of the main steam is relatively high, close to the decomposition temperature of the commonly used molten salt (i.e. solar salt, composed of 40% potassium nitrate + 60% sodium nitrate), the molten salt in the steam molten salt heat exchanger will be at risk of decomposition, and the main steam needs to be cooled and decompressed before being sent to the steam molten salt heat exchange system to heat the cold molten salt. In addition, since a large amount of high-quality main steam is extracted to heat the molten salt, it becomes low-quality steam after heating and returns to the high-pressure cylinder exhaust steam and the medium-pressure cylinder exhaust steam, and then returns to the original thermal system, so Figure 3 In order to keep the output of the original steam turbine generator set unchanged, the system design shown must significantly increase the flow of main steam and reheat steam, which are ultimately sent to the condenser as waste steam. This significantly increases the heat loss rate at the cold end, causing a significant drop in the efficiency of the steam turbine generator set.

[0050] The system designed in this embodiment 1 adds a first-stage reheating system to the boiler, and the pressure is basically the original first reheating pressure, the pressure is moderate, and the heat exchanger has good matching. The temperature of the first reheated steam after the first heating is about 575°C, which matches the temperature of the steam molten salt heat exchanger 3, and there is no risk of cooling loss or molten salt decomposition. The thermal power generation system designed in this embodiment 1, which is coupled with the peak operation of molten salt energy storage, only needs to consider the steam resistance loss of the steam molten salt heat exchanger, the boiler reheater and the pipeline (the pressure loss is about 1.0MPa), does not need to be reduced, and there is no throttling loss. Most importantly, compared with the original steam turbine generator set steam inlet system, in order to offset the above-mentioned steam resistance loss, only the inlet and outlet pressure of the steam turbine high-pressure cylinder 2 is increased by 1.0MPa, the steam flow rate remains unchanged, there is no increase in the cold section loss of the condenser 13, and the energy-saving benefit is obvious.

[0051] The thermal power generation system coupled with molten salt energy storage peak operation designed in this embodiment 1 increases the pressure of the inlet and outlet of the steam turbine high-pressure cylinder 2 by 1.0 MPa on the basis of a conventional primary reheat unit, and at the same time, the exhaust steam of the conventional steam turbine high-pressure cylinder 2 is sent to the combustion boiler 1 for reheating through the primary reheater 17 to form primary reheat steam, which is reheated to the steam temperature required by the steam molten salt heat exchanger 3, and then the primary reheat steam is sent to the steam molten salt heat exchanger 3 to complete heat exchange with the cold molten salt, and the cooled primary reheat steam (about 320°C) is then sent to the combustion boiler 1 for further reheating through the secondary reheater 18 to form secondary reheat steam, that is, a reheat system is added to the boiler 1, which is similar to the principle of the secondary reheat boiler, and the secondary reheat steam after the secondary reheating is sent to the steam turbine intermediate pressure cylinder 10 to continue to expand and do work.

[0052] For the molten salt energy storage system, a dual tank system of cold and hot molten salt tanks is set. In the energy storage condition, the cold molten salt (temperature of about 290°C) in the cold molten salt tank 4 is sent to the steam molten salt heat exchanger 3 through the cold molten salt pump 7, and the hot molten salt (temperature of about 565°C) is formed after heat exchange with the primary reheat steam, and then the hot molten salt is sent to the hot molten salt tank 5 for storage. In the peak power generation operation condition, the hot molten salt in the hot molten salt tank 5 is sent to the steam generator 6 through the hot molten salt pump 8, and the high-temperature molten salt is used to heat the steam-water medium to generate high-temperature and high-pressure steam, which is then sent to the independent steam turbine generator set 6 for power generation. The heated hot molten salt becomes low-temperature molten salt and is then sent to the cold molten salt tank 4, so as to be recycled. The above temperature is the typical system design temperature using commonly used molten salt (40% potassium nitrate + 60% sodium nitrate). Other molten salts can also be used as energy storage media, and their temperatures need to be designed and calculated according to the characteristics of the molten salt.

[0053] For conventional steam turbine generator sets, from the perspective of heat utilization (the first law of thermodynamics: the principle of energy conservation), there is a large amount of heat loss in the condenser 13, and a large amount of waste heat is taken away by the condensed water; and from the perspective of energy quality (the second law of thermodynamics: the principle of entropy increase), a large amount of heat loss exists on the boiler side, because the end difference between the high-temperature flue gas of more than 1000°C generated by the combustion of coal and the steam heat exchange process causes Therefore, the conventional steam extraction storage solution causes a large amount of loss due to the pressure reduction. The loss is manifested in that under the same power generation conditions, the steam flow rate is greatly increased due to the reduction in steam quality, which increases the cold end loss of the condenser.

[0054] The utility model adds a first-stage reheating system, which substantially reduces the average end difference between the flue gas side and the steam side during the boiler heat exchange process and reduces In the steam molten salt heat exchanger 3, the temperature and pressure parameters match each other, and the heat exchange loss is small. This is reflected in the unchanged steam flow of the original steam turbine generator set, the cold end loss in the condenser remains basically unchanged, and the energy in the heat storage and heat exchange process is basically effectively utilized.

[0055] Specifically, according to the conventional 660MW unit, the set unit parameters are shown in the following table:

[0056] Table 1 is a comparison of the thermal parameters of a 660MW unit and the system after adopting this embodiment 1

[0057]

[0058]

[0059] Note: The heat exchangers described in No. 14 to No. 16 in Table 1 refer to the steam molten salt heat exchanger 3; the steam at the inlet of the intermediate pressure cylinder No. 17 to No. 19 is equivalent to the primary hot steam formed by the steam exhausted from the high pressure cylinder and heated once by the boiler in the conventional single reheat unit, while in the unit of this embodiment 1 it refers to the secondary reheat steam.

[0060] As can be seen from Table 1 above, the thermal power generation system coupled with molten salt energy storage peak operation designed by the utility model has a feed water pressure and a main steam pressure increased by 1.0 MPa compared with the existing conventional thermal power plant compared with the conventional single reheat unit, and the flow rate and temperature are consistent with the existing single reheat unit; the steam temperature at the outlet section of the high-pressure cylinder is consistent with the original unit, the flow rate is the same, and the pressure is also increased by 1.0 MPa, and the single reheat steam (about 575°C) after the single heating by the combustion boiler 1 is sent to the steam molten salt heat exchanger 3 to heat the cold molten salt; the single reheat steam after heating the cold molten salt is cooled into low-temperature steam (about 320°C) and is continuously sent to the combustion boiler 1 for secondary heat absorption to form secondary reheat steam (about 605°C), and then the secondary reheat steam is sent to the original steam turbine intermediate pressure cylinder 10 to do work, and the secondary reheat steam is also consistent with the steam parameters at the inlet of the intermediate pressure cylinder of the original steam turbine generator set.

[0061] Therefore, in general, for the steam turbine generator set, the system designed by the utility model, except for the main steam pressure, feed water pressure and high-pressure cylinder outlet section pressure increased by 1.0MPa, all other including the thermal system remain unchanged; it becomes secondary reheating on the boiler side, which is the same as the principle of a conventional secondary reheat boiler, wherein the temperature of the primary reheat steam is about 575°C, which is used to heat the cold molten salt. After heating the cold molten salt, it becomes steam at about 320°C and is sent back to the boiler for secondary reheating.

[0062] Compared with the original conventional single-reheat unit, the system of this embodiment 1 has a total boiler heat absorption storage increased by about 21%. Based on this calculation, keeping the original steam turbine generator set processing unchanged, and calculating by converting the boiler into full-load operation for 20 hours, the thermal power generation system coupled with molten salt energy storage peak operation designed in this embodiment 1 has the ability to increase the peak operation of 300MW units for 8 hours, which is equivalent to adding a 300MW×8-hour energy storage power station. The energy storage effect is excellent and the thermal efficiency is basically unchanged. It is equivalent to directly using the energy generated by coal burning in the boiler to directly heat the molten salt storage, reducing the energy loss of the system.

[0063] The above preferred embodiments of the utility model are only used to explain the utility model, and are not used to limit the utility model. Any obvious changes or modifications derived from the technical solution of the utility model are still within the protection scope of the utility model.

Claims

1. A thermal power generation system coupled with molten salt energy storage peak operation, characterized in that: The thermal power generation system comprises: A combustion boiler (1) which generates high-temperature, high-pressure main steam; The main steam enters the high-pressure cylinder (2) of the steam turbine to perform work, and then returns to the combustion boiler (1) to be reheated once, so as to form primary reheated steam; Molten salt energy storage system, the primary reheated steam enters the molten salt energy storage system to provide heat for the molten salt energy storage system and store energy, and then returns to the combustion boiler (1) for secondary reheating to form secondary reheated steam; The secondary reheated steam enters the steam turbine intermediate pressure cylinder (10) to perform work and then enters the steam turbine low pressure cylinder (11) to continue to perform work. The steam turbine high pressure cylinder (2), the steam turbine intermediate pressure cylinder (10) and the steam turbine low pressure cylinder (11) coaxially drive the main steam turbine generator set (12) to generate electricity; and a condenser (13), wherein the secondary reheated steam enters the condenser (13) after being exhausted from the low-pressure cylinder (11) of the steam turbine to form condensed water, and then enters the combustion boiler (1).

2. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 1, characterized in that: A main steam valve (14) is provided at the inlet of the high-pressure cylinder (2) of the steam turbine.

3. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 1, characterized in that: The molten salt energy storage system includes the following: A steam molten salt heat exchanger (3), wherein the primary reheated steam enters the steam molten salt heat exchanger (3) as a heat source to provide heat thereto, and then returns to the combustion boiler (1) to be heated again to form secondary reheated steam; A cold molten salt tank (4) storing cold molten salt, wherein the cold molten salt is heated and stored in the steam molten salt heat exchanger (3) to become hot molten salt and enter the hot molten salt tank (5) for storage; The molten salt stored in the molten salt tank (5) is used as a heat source to enter the steam generator and the steam turbine generator set (6) to provide heat for the steam generator and the steam turbine generator set, so that the steam is generated and the steam turbine generator is driven to generate electricity. After providing heat, the molten salt becomes cold molten salt and enters the cold molten salt tank (4).

4. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 3, characterized in that: The molten salt energy storage system further comprises a cold molten salt pump (7) and a hot molten salt pump (8); The cold molten salt pump (7) is used to pump the cold molten salt into the steam molten salt heat exchanger (3) for heating and energy storage and then into the hot molten salt tank (5) for storage; the hot molten salt pump (8) is used to pump the hot molten salt into the steam generator and steam turbine generator set (6) for heat supply and energy release and then into the cold molten salt tank (4).

5. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 3, characterized in that: The thermal power generation system further comprises a bypass valve (9); The bypass valve (9) is arranged in parallel with the steam molten salt heat exchanger (3) and is used to divert the primary reheat steam entering the steam molten salt heat exchanger (3).

6. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 1, characterized in that: The steam turbine low-pressure cylinder (11) is arranged in two groups and is arranged in parallel.

7. A thermal power generation system coupled with molten salt energy storage peak operation according to claim 1, characterized in that: The thermal power generation system further comprises a condensate pump (15) and a feed water heat recovery system (16); The condensate formed in the condenser (13) is pumped into the feed water heat recovery system (16) through the condensate pump (15), and then enters the combustion boiler (1) through the high-pressure feed water of the feed water heat recovery system (16).

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