Deaerator system and method for comprehensively utilizing energy of molten salt thermoelectric decoupling system

Abstract

The invention belongs to the technical field of fused salt steam heat exchange systems, and particularly relates to a deaerator system and method for comprehensively utilizing energy of a fused salt thermoelectric decoupling system. The system comprises a thermal power generating unit, a fused salt heat storage unit for heating fused salt through steam, a fused salt heat release unit for heating water and steam through fused salt, a steam supply header and a fused salt system deaerator, and a main steam outlet of the thermal power generating unit is connected with the fused salt heat storage unit through a pipeline. A steam outlet of the fused salt heat storage unit and a steam outlet of the fused salt heat release unit are both connected with a steam supply header through pipelines, and the fused salt heat release unit, an outlet of a low-pressure heater of the thermal power generating unit, an outlet of the steam supply header and a condenser front water supplementing device are all connected with an inlet of a fused salt system deaerator through pipelines. And an outlet of the molten salt system deaerator is connected with the molten salt heat release system through a pipeline. The invention provides a deaerator system and method for comprehensively utilizing energy of a molten salt thermoelectric decoupling system.

Description

Technical Field

[0001] The present invention belongs to the technical field of molten salt steam heat exchange systems, and in particular relates to a deaerator system and method for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system. Background Art

[0002] As the proportion of renewable energy power generation increases, my country's energy structure adjustment continues to upgrade. The difficulty of traditional thermal power units to participate in large-scale thermal regulation in the "heat-based electricity" working mode has increased, and they cannot meet the needs of flexible scheduling. As a technology that is not restricted by energy time and space, energy storage can meet the load regulation needs of peak shaving and valley filling by coupling with thermal power generating units. Among them, molten salt energy storage has the advantages of large energy storage capacity, long storage cycle, and low cost. Its coupling with traditional thermal power units can achieve thermal and electric decoupling and provide industrial steam, achieving the effect of "top peaks and suppress valleys".

[0003] As a stable medium- and high-temperature heat storage medium, molten salt has the advantages of high heat capacity and non-flammability, but its freezing point is relatively high. When the molten salt energy storage system is coupled with a thermal power unit, if the temperature of the working fluid that exchanges heat with the molten salt is low, the molten salt will have the risk of solidification. After solidification in the heat exchanger, it is extremely difficult to handle, which may cause the heat exchanger to be directly scrapped. Based on this feature, for a thermoelectric decoupled unit that uses steam to heat molten salt, the latent heat of the steam that exchanges heat with the molten salt is difficult to utilize; for the molten salt exothermic process, the temperature of the water working fluid that exchanges heat with it must be higher than the freezing point of the salt. The steam generation system feed water of the thermal power unit-molten salt system usually comes from the unit deaerator. Providing a higher temperature feed water to the steam generation system will increase its operating load, making the thermal balance of the unit deaerator more complicated, resulting in reduced unit operation stability; if the desalted water of the power plant is directly used as the steam generation system feed water, the molten salt will have the risk of solidification. Summary of the invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a deaerator system and method that comprehensively utilizes the energy of a molten salt thermoelectric decoupling system, utilizing the common advantages of the coupling of thermoelectric decoupling thermal power units and molten salt systems, fully regulating the heat source and water source under different working conditions, and comprehensively utilizing the system energy while ensuring that the water supply to the steam generation system will not cause the molten salt to solidify, thereby ensuring that the system can operate safely and efficiently.

[0005] The technical solution adopted by the present invention is:

[0006] A deaerator system for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system comprises a thermal power unit, a molten salt heat storage unit for heating molten salt with steam, a molten salt heat release unit for heating water and steam with molten salt, a steam supply header and a molten salt system deaerator, wherein a main steam outlet of the thermal power unit is connected to the molten salt heat storage unit through a pipeline, a steam outlet of the molten salt heat storage unit and a steam outlet of the molten salt heat release unit are both connected to the steam supply header through a pipeline, an outlet of the molten salt heat release unit, a low-pressure heater of the thermal power unit, an outlet of the steam supply header and a water supply device before a condenser are all connected to an inlet of a molten salt system deaerator through a pipeline, and an outlet of the molten salt system deaerator is connected to a molten salt heat release system through a pipeline.

[0007] For the molten salt energy storage system, steam from the thermal power unit is extracted and enters the molten salt heat storage unit to heat the molten salt. The steam after heating the molten salt and the steam at the outlet of the molten salt heat release unit enter the steam supply manifold for external supply.

[0008] For the steam generation system, the molten salt system deaerator has multiple heat sources and water sources: the heat source is the high-temperature water working medium of the steam heat release unit and the excess steam from the steam supply header, and the water source is the outlet water of the low-pressure heater of the thermal power unit feed water system and the make-up water before the condenser. Under different working conditions, by adjusting the regulating valves of each pipeline, the thermal parameters of the heat source and the water source are matched to ensure that the feed water temperature entering the molten salt heat release unit at the outlet of the molten salt system deaerator is higher than the solidification point of the molten salt. The superheated steam generated after the heat exchange between the feed water and the molten salt enters the steam supply header for external supply.

[0009] The present invention separately arranges a molten salt system deaerator for the molten salt system, which weakens the influence on the original deaerator of the thermal power unit during thermoelectric decoupling and can ensure the stable operation of the system.

[0010] The present invention flexibly regulates the heat source and water source of the deaerator of the molten salt system to ensure that the molten salt of the steam generation system does not solidify and the system operates safely.

[0011] The present invention fully utilizes the common advantages of the thermoelectric decoupled thermal power unit and the molten salt system coupling to achieve comprehensive utilization of energy and improve the energy utilization rate of the entire system.

[0012] As a preferred solution of the present invention, a first regulating valve is connected to the pipeline between the molten salt heat release unit and the inlet of the molten salt system deaerator, a second regulating valve is connected to the pipeline between the outlet of the low-pressure heater of the thermal power unit and the inlet of the molten salt system deaerator, a third regulating valve is connected to the pipeline between the outlet of the steam supply manifold and the inlet of the molten salt system deaerator, and a fourth regulating valve is connected to the pipeline between the pre-condenser water supply equipment and the inlet of the molten salt system deaerator. Under different working conditions, by adjusting the first regulating valve, the second regulating valve, the third regulating valve and the fourth regulating valve, the thermal parameters of the heat source and the water source are matched to ensure that the feed water temperature entering the molten salt heat release unit at the outlet of the molten salt system deaerator is higher than the solidification point of the molten salt.

[0013] As a preferred embodiment of the present invention, the thermal power unit includes a boiler, the molten salt heat storage unit includes a steam molten salt heat exchanger, the main steam outlet of the boiler is connected to the steam inlet of the steam molten salt heat exchanger through a pipeline, the steam outlet of the steam molten salt heat exchanger is respectively connected to the reheat inlet and the steam supply manifold of the boiler through pipelines, the reheat steam outlet of the boiler is connected to the steam turbine through a pipeline, the steam outlet of the steam turbine is sequentially connected to a condensate pump, a low-pressure heater and a deaerator through pipelines, the middle section of the steam turbine is connected to the deaerator through a pipeline, and the outlet of the deaerator is connected to the main inlet of the boiler through a pipeline.

[0014] As a preferred embodiment of the present invention, the reheat steam outlet of the boiler is also connected to the steam molten salt heat exchanger through a pipeline.

[0015] As a preferred embodiment of the present invention, the middle section of the steam turbine is also connected to the steam molten salt heat exchanger through a pipeline.

[0016] As a preferred embodiment of the present invention, the molten salt heat release unit includes a preheater, a steam drum, an evaporator and a superheater. The water supply inlet of the preheater is connected to the outlet of the molten salt system deaerator through a pipeline, the water supply outlet of the preheater is connected to the inlet of the molten salt system deaerator through a pipeline, the water supply outlet of the preheater is also connected to the steam drum through a pipeline, the inlet and outlet of the evaporator are respectively connected to the steam drum through pipelines, the steam outlet of the steam drum is connected to the superheater through a pipeline, and the steam outlet of the superheater is connected to the steam supply manifold through a pipeline. The water supply at the outlet of the molten salt system deaerator passes through a feed water pump and enters the preheater, evaporator, steam drum and superheater in sequence. The superheated steam generated after the heat exchange between the water supply and the molten salt enters the steam supply manifold for external supply.

[0017] As a preferred solution of the present invention, a molten salt system water feed pump is connected to the pipeline between the outlet of the molten salt system deaerator and the water supply inlet of the preheater.

[0018] As a preferred solution of the present invention, the steam supply manifold is connected to an external steam supply unit via a pipeline.

[0019] A method for comprehensively utilizing energy from a molten salt thermal-electric decoupling system comprises the following steps:

[0020] Regulate the steam and water sources entering the molten salt system deaerator: the high-temperature water working medium at the outlet of the steam generation system preheater, the excess steam from the steam supply manifold, the outlet water of the low-pressure heater of the thermal power unit feed water system, and the make-up water before the condenser; match the thermal parameters of the heat source and the water source to ensure that the feed water temperature entering the preheating molten salt exothermic unit at the outlet of the molten salt system deaerator is higher than the solidification point of the molten salt.

[0021] As a preferred solution of the present invention, the steam of the steam supply manifold comes from the outlet steam of the molten salt heat storage unit and the outlet steam of the molten salt heat release unit.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention separately sets a molten salt system deaerator for the molten salt system, which weakens the influence of the original deaerator of the thermal power unit during the thermal-electric decoupling and can ensure the stable operation of the system.

[0024] 2. The present invention flexibly regulates the heat source and water source of the deaerator of the molten salt system to ensure that the molten salt of the steam generation system does not solidify and the system operates safely.

[0025] 3. The present invention makes full use of the common advantages of the thermoelectric decoupled thermal power unit and the molten salt system coupling to achieve comprehensive utilization of energy and improve the energy utilization rate of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] In the figure: 1- boiler; 2- steam turbine; 3- condensate pump; 4- low-pressure heater; 5- deaerator; 6- steam molten salt heat exchanger; 7- molten salt system deaerator; 8- feed water pump; 9- preheater; 10- evaporator; 11- steam drum; 12- superheater; 13- steam supply manifold; 14- first regulating valve; 15- second regulating valve; 13- third regulating valve; 14- fourth regulating valve. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0030] like Figure 1As shown, the deaerator system of the embodiment that comprehensively utilizes the energy of the molten salt thermoelectric decoupling system includes a thermal power unit, a molten salt heat storage unit that heats molten salt with steam, a molten salt heat release unit that heats water and steam with molten salt, a steam supply header 13 and a molten salt system deaerator 7. The main steam outlet of the thermal power unit is connected to the molten salt heat storage unit through a pipeline, and the steam outlet of the molten salt heat storage unit and the steam outlet of the molten salt heat release unit are both connected to the steam supply header 13 through a pipeline. The molten salt heat release unit, the outlet of the low-pressure heater 4 of the thermal power unit, the outlet of the steam supply header 13 and the pre-condenser water supply equipment are all connected to the inlet of the molten salt system deaerator 7 through a pipeline, and the outlet of the molten salt system deaerator 7 is connected to the molten salt heat release system through a pipeline.

[0031] For the molten salt energy storage system, steam from the thermal power unit is extracted and enters the molten salt heat storage unit to heat the molten salt. The steam after heating the molten salt and the steam at the outlet of the molten salt heat release unit enter the steam supply manifold 13 for external supply.

[0032] For the steam generation system, the molten salt system deaerator 7 has multiple heat sources and water sources: the heat source is the high-temperature water working medium of the steam heat release unit and the excess steam from the steam supply header 13, and the water source is the outlet water of the low-pressure heater 4 of the thermal power unit feed water system and the make-up water before the condenser. Under different working conditions, by adjusting the regulating valves of each pipeline, the thermal parameters of the heat source and the water source are matched to ensure that the feed water temperature entering the molten salt heat release unit at the outlet of the molten salt system deaerator 7 is higher than the solidification point of the molten salt. The superheated steam generated after the heat exchange between the feed water and the molten salt enters the steam supply header 13 for external supply.

[0033] The present invention separately sets a molten salt system deaerator 7 for the molten salt system, which weakens the influence of the original deaerator 5 of the thermal power unit during the thermoelectric decoupling and can ensure the stable operation of the system.

[0034] The present invention flexibly regulates the heat source and water source of the molten salt system deaerator 7 to ensure that the molten salt of the steam generation system does not solidify and the system operates safely.

[0035] The present invention fully utilizes the common advantages of the thermoelectric decoupled thermal power unit and the molten salt system coupling to achieve comprehensive utilization of energy and improve the energy utilization rate of the entire system.

[0036] Among them, the pipeline between the molten salt heat release unit and the inlet of the molten salt system deaerator 7 is connected with a first regulating valve 14, the pipeline between the outlet of the low-pressure heater 4 of the thermal power unit and the inlet of the molten salt system deaerator 7 is connected with a second regulating valve 15, the pipeline between the outlet of the steam supply manifold 13 and the inlet of the molten salt system deaerator 7 is connected with a third regulating valve 13, and the pipeline between the pre-condenser water supply equipment and the inlet of the molten salt system deaerator 7 is connected with a fourth regulating valve 14. Under different working conditions, by adjusting the first regulating valve 14, the second regulating valve 15, the third regulating valve 13 and the fourth regulating valve 14, the thermal parameters of the heat source and the water source are matched to ensure that the feed water temperature entering the molten salt heat release unit at the outlet of the molten salt system deaerator 7 is higher than the solidification point of the molten salt.

[0037] Specifically, the thermal power unit includes a boiler 1, and the molten salt heat storage unit includes a steam molten salt heat exchanger 6. The main steam outlet of the boiler 1 is connected to the steam inlet of the steam molten salt heat exchanger 6 through a pipeline, and the steam outlet of the steam molten salt heat exchanger 6 is respectively connected to the reheat inlet of the boiler 1 and the steam supply manifold 13 through pipelines. The reheat steam outlet of the boiler 1 is connected to the steam turbine 2 through a pipeline, and the steam outlet of the steam turbine 2 is sequentially connected to the condensate pump 3, the low-pressure heater 4 and the deaerator 5 through pipelines. The middle section of the steam turbine 2 is connected to the deaerator 5 through a pipeline, and the outlet of the deaerator 5 is connected to the main inlet of the boiler 1 through a pipeline.

[0038] Furthermore, the reheat steam outlet of the boiler 1 is also connected to the steam molten salt heat exchanger 6 through a pipeline.

[0039] Furthermore, the middle section of the steam turbine 2 is also connected to the steam molten salt heat exchanger 6 through a pipeline.

[0040] Specifically, the molten salt heat release unit includes a preheater 9, a drum 11, an evaporator 10 and a superheater 12. The water supply inlet of the preheater 9 is connected to the outlet of the molten salt system deaerator 7 through a pipeline, the water supply outlet of the preheater 9 is connected to the inlet of the molten salt system deaerator 7 through a pipeline, the water supply outlet of the preheater 9 is also connected to the drum 11 through a pipeline, the inlet and outlet of the evaporator 10 are respectively connected to the drum 11 through pipelines, the steam outlet of the drum 11 is connected to the superheater 12 through a pipeline, and the steam outlet of the superheater 12 is connected to the steam supply header 13 through a pipeline. The outlet feed water of the molten salt system deaerator 7 enters the preheater 9, the evaporator 10, the drum 11 and the superheater 12 in sequence after passing through the feed water pump 8, and the superheated steam generated after the feed water and the molten salt heat exchange enters the steam supply header 13 for external supply.

[0041] A molten salt system water supply pump 8 is connected to the pipeline between the outlet of the molten salt system deaerator 7 and the water supply inlet of the preheater 9.

[0042] The steam supply manifold 13 is connected to an external steam supply unit via a pipeline.

[0043] The method for comprehensively utilizing the energy of the molten salt thermoelectric decoupling system of this embodiment includes the following steps:

[0044] Regulate the steam source and water source entering the molten salt system deaerator 7: the high-temperature water working medium at the outlet of the steam generation system preheater 9, the excess steam from the steam supply manifold 13, the outlet water of the low-pressure heater 4 of the thermal power unit feed water system, and the make-up water before the condenser; match the thermal parameters of the heat source and the water source to ensure that the feed water temperature entering the preheating molten salt exothermic unit at the outlet of the molten salt system deaerator 7 is higher than the solidification point of the molten salt.

[0045] The steam of the steam supply manifold 13 comes from the outlet steam of the molten salt heat storage unit and the outlet steam of the molten salt heat release unit.

[0046] For the molten salt system deaerator 7, the present invention proposes for the first time the allocation of multiple heat sources and water sources: the heat source is the high-temperature water working medium at the outlet of the preheater 9 and the excess steam from the steam supply manifold 13, and the water source is the outlet water of the low-pressure heater 4 of the water supply system of the thermal power unit and the make-up water before the condenser. Under different working conditions, by matching the thermal parameters of the heat source and the water source, it is ensured that the feed water temperature entering the preheater 9 at the outlet of the molten salt system deaerator 7 is higher than the solidification point of the molten salt. In addition, part of the heat source of the molten salt system deaerator 7 in the present invention is the excess steam in the steam supply manifold 13, and the steam source in the steam supply manifold 13 is the steam after the thermal power unit heats the molten salt and the steam generated by the steam generation system. Through the reasonable allocation of the above-mentioned heat source, steam source and water source, the system can realize the cascade utilization of energy after the unit is coupled to the molten salt system, which is convenient for the flexible regulation of the load of the thermal power unit and the steam generation system under different working conditions.

[0047] In summary, the present invention sets a molten salt system deaerator 7 for the molten salt system separately, which can avoid the original unit deaerator 5 from becoming more complicated in thermal balance after coupling with the molten salt system, and ensure the stable operation of the system. At the same time, the system of the present invention can flexibly regulate the heat source and water source of the molten salt system deaerator 7, while ensuring that the molten salt of the steam generation system does not solidify and operates safely, it can fully utilize the common advantages of the thermoelectric decoupling thermal power unit and the molten salt system coupling, realize the comprehensive utilization of energy, and improve the energy utilization rate of the entire system.

[0048] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A deaerator system that comprehensively utilizes the energy of a molten salt thermoelectric decoupling system, characterized in that: The invention comprises a thermal power unit, a molten salt heat storage unit for heating molten salt with steam, a molten salt heat release unit for heating water and steam with molten salt, a steam supply header (13) and a molten salt system deaerator (7); the main steam outlet of the thermal power unit is connected to the molten salt heat storage unit through a pipeline; the steam outlet of the molten salt heat storage unit and the steam outlet of the molten salt heat release unit are both connected to the steam supply header (13) through a pipeline; the molten salt heat release unit, the outlet of the low-pressure heater (4) of the thermal power unit, the outlet of the steam supply header (13) and the water supply equipment before the condenser are all connected to the inlet of the molten salt system deaerator (7) through a pipeline; and the outlet of the molten salt system deaerator (7) is connected to the molten salt heat release system through a pipeline.

2. A deaerator system for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system according to claim 1, characterized in that: A first regulating valve (14) is connected to the pipeline between the molten salt heat release unit and the inlet of the molten salt system deaerator (7), a second regulating valve (15) is connected to the pipeline between the outlet of the low-pressure heater (4) of the thermal power unit and the inlet of the molten salt system deaerator (7), a third regulating valve (13) is connected to the pipeline between the outlet of the steam supply manifold (13) and the inlet of the molten salt system deaerator (7), and a fourth regulating valve (14) is connected to the pipeline between the pre-condenser water supply equipment and the inlet of the molten salt system deaerator (7).

3. The deaerator system for comprehensively utilizing the energy of the molten salt thermoelectric decoupling system according to claim 1 is characterized in that: The thermal power unit comprises a boiler (1); the molten salt heat storage unit comprises a steam molten salt heat exchanger (6); the main steam outlet of the boiler (1) is connected to the steam inlet of the steam molten salt heat exchanger (6) through a pipeline; the steam outlet of the steam molten salt heat exchanger (6) is respectively connected to the reheat inlet of the boiler (1) and a steam supply manifold (13) through pipelines; the reheat steam outlet of the boiler (1) is connected to a steam turbine (2) through a pipeline; the steam outlet of the steam turbine (2) is sequentially connected to a condensate pump (3), a low-pressure heater (4) and a deaerator (5) through pipelines; the middle section of the steam turbine (2) is connected to the deaerator (5) through a pipeline; and the outlet of the deaerator (5) is connected to the main steam inlet of the boiler (1) through a pipeline.

4. A deaerator system for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system according to claim 3, characterized in that: The reheat steam outlet of the boiler (1) is also connected to the steam molten salt heat exchanger (6) via a pipeline.

5. A deaerator system for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system according to claim 3, characterized in that: The middle section of the steam turbine (2) is also connected to the steam molten salt heat exchanger (6) via a pipeline.

6. A deaerator system for comprehensively utilizing the energy of a molten salt thermal-electric decoupling system according to claim 1, characterized in that: The molten salt heat release unit comprises a preheater (9), a steam drum (11), an evaporator (10) and a superheater (12); the water supply inlet of the preheater (9) is connected to the outlet of a molten salt system deaerator (7) through a pipeline; the water supply outlet of the preheater (9) is connected to the inlet of the molten salt system deaerator (7) through a pipeline; the water supply outlet of the preheater (9) is also connected to the steam drum (11) through a pipeline; the inlet and outlet of the evaporator (10) are respectively connected to the steam drum (11) through pipelines; the steam outlet of the steam drum (11) is connected to the superheater (12) through a pipeline; and the steam outlet of the superheater (12) is connected to a steam supply manifold (13) through a pipeline.

7. A deaerator system for comprehensively utilizing the energy of a molten salt thermal-electric decoupling system according to claim 6, characterized in that: A molten salt system water supply pump (8) is connected to the pipeline between the outlet of the molten salt system deaerator (7) and the water supply inlet of the preheater (9).

8. The deaerator system for comprehensively utilizing the energy of the molten salt thermal-electric decoupling system according to claim 1 is characterized in that: The steam supply header (13) is connected to an external steam supply unit via a pipeline.

9. A method for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system, using the deaerator system for comprehensively utilizing the energy of a molten salt thermoelectric decoupling system according to claim 1, characterized in that: The following steps are involved: The steam source and water source entering the molten salt system deaerator (7) are adjusted: the high-temperature water working medium at the outlet of the steam generation system preheater (9), the surplus steam from the steam supply manifold (13), the outlet water of the low-pressure heater (4) of the thermal power unit feed water system, and the feed water before the condenser; the thermal parameters of the heat source and the water source are matched to ensure that the feed water temperature entering the preheating molten salt heat release unit at the outlet of the molten salt system deaerator (7) is higher than the solidification point of the molten salt.

10. The method for comprehensive utilization of energy of molten salt thermal-electric decoupling system according to claim 9, characterized in that: The steam of the steam supply manifold (13) comes from the outlet steam of the molten salt heat storage unit and the outlet steam of the molten salt heat release unit.

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