CN-120626300-B - High-pressure steam supply system for coupling fused salt heat storage

CN120626300BCN 120626300 BCN120626300 BCN 120626300BCN-120626300-B

Abstract

The invention discloses a high-pressure steam supply system for coupling molten salt heat storage. The high-pressure steam supply system comprises a back press, a main steam outlet of a boiler is communicated with a steam inlet of the back press, a primary reheating intermediate reheater and a primary reheating secondary reheater are arranged in the boiler, the steam outlet of the primary reheating intermediate reheater is respectively communicated with the steam inlet of the primary reheating secondary reheater and the steam inlet of the back press, the main steam diverter valve is used for controlling on-off between the main steam outlet and the steam inlet of the back press, and the reheating steam diverter valve is used for controlling on-off between the steam outlet of the primary reheating intermediate reheater and the steam inlet of the back press. According to the high-pressure steam supply system for coupling molten salt heat storage, the high-pressure steam supply system for coupling molten salt heat storage can realize energy cascade utilization, meanwhile, the station service power rate of a unit is reduced, and the peak regulation capacity of the unit can be effectively improved.

Inventors

DING LIANSHENG
CHEN JIANXIAN
HE XINRONG
ZHANG BIAO
CHEN CHEN
YANG XIAOWEI
HU YONGJIA
ZHANG BIN
ZANG BO
ZHANG YIN

Assignees

国能(浙江北仑)发电有限公司
国能南京电力试验研究有限公司

Dates

Publication Date: 20260512
Application Date: 20250612

Claims (7)

1. The high-pressure steam supply system for coupling molten salt heat storage is characterized by comprising a coal-fired unit and a high-pressure steam supply system, wherein the high-pressure steam supply system comprises a back press, and the coal-fired unit comprises: The boiler is provided with a main steam outlet which is communicated with a steam inlet of the back press, a primary reheating intermediate reheater and a primary reheating secondary reheater are arranged in the boiler, and the steam outlet of the primary reheating intermediate reheater is respectively communicated with the steam inlet of the primary reheating secondary reheater and the steam inlet of the back press; the main steam outlet is communicated with a steam inlet of the turbine ultrahigh pressure cylinder, and the steam outlet of the turbine ultrahigh pressure cylinder is communicated with a steam inlet of the primary reheating intermediate reheater; the steam outlet of the primary reheating secondary reheater is communicated with the steam inlet of the steam turbine high-pressure cylinder; the main steam diverter valve is used for controlling the on-off between the main steam outlet and the steam inlet of the back press; the reheating steam diverter valve is used for controlling the on-off between the steam outlet of the primary reheating intermediate reheater and the steam inlet of the back press; The high-pressure steam supply system also comprises a temperature and pressure reduction device, wherein the temperature and pressure reduction device is provided with a steam inlet and a liquid inlet, the steam outlet of the back pressure machine is communicated with the steam inlet, the liquid inlet is communicated with the water working medium outlet of the deaerator, and the steam outlet of the temperature and pressure reduction device is communicated with a steam supply main pipe for supplying heat; The high-pressure steam supply system for coupling molten salt heat accumulation further comprises a molten salt heat accumulation system, molten salt circularly flows in the molten salt heat accumulation system, and the molten salt heat accumulation system comprises: the molten salt heat storage system comprises a low-temperature molten salt tank, a high-temperature molten salt tank and a molten salt electric heater, wherein a first flow path is arranged in the molten salt electric heater and is used for heating molten salt in the first flow path, and two ends of the first flow path are respectively communicated with an outlet of the low-temperature molten salt tank and an inlet of the high-temperature molten salt tank so as to form a heat storage loop of the molten salt heat storage system; The low-temperature molten salt pump is arranged between the low-temperature molten salt tank and the molten salt electric heater and is used for driving molten salt to circularly flow; The water supply-molten salt heat exchanger is internally provided with a first channel and a second channel which exchange heat with each other, the outlet end of the first channel is communicated with the inlet of the low-temperature molten salt tank, and the inlet end of the second channel is communicated with the hydraulic medium outlet of the deaerator; The superheated steam-molten salt heat exchanger is internally provided with a third channel and a fourth channel which exchange heat with each other, the inlet end of the third channel is communicated with the outlet of the high-temperature molten salt tank, and the outlet end of the fourth channel is communicated with the steam inlet of the primary reheating intermediate reheater through a molten salt steam supply pipeline; The saturated steam-molten salt heat exchanger is internally provided with a fifth channel and a sixth channel which exchange heat with each other, two ends of the fifth channel are respectively communicated with the outlet end of the third channel and the inlet end of the first channel, and two ends of the sixth channel are respectively communicated with the outlet end of the second channel and the inlet end of the fourth channel; the inlet end of the steam drum is communicated with the outlet end of the sixth channel, the steam drum is used for separating saturated steam from water, the steam drum is provided with a steam outlet and a liquid outlet, the steam outlet is communicated with the inlet end of the fourth channel, and the liquid outlet is communicated with the inlet end of the second channel; A high-temperature molten salt pump arranged between the high-temperature molten salt tank and the superheated steam-molten salt heat exchanger and used for driving molten salt to circularly flow, The high-temperature molten salt tank, the third channel, the fifth channel, the first channel and the low-temperature molten salt tank form a heat release loop of the molten salt heat storage system.
2. The coupled molten salt heat storage high pressure steam supply system of claim 1 wherein the coal-fired unit further comprises a generator through which the low temperature molten salt pump is driven.
3. The coupled molten salt heat storage high pressure steam supply system of claim 1 wherein the feedwater-molten salt heat exchanger, the saturated steam-molten salt heat exchanger, and the superheated steam-molten salt heat exchanger are all divided wall water-molten salt heat exchangers.
4. The coupled molten salt heat storage high pressure steam supply system of claim 1 further comprising: The water supply bypass water pump is used for driving water to flow from a water working medium outlet of the deaerator to an inlet end of the second channel and a liquid inlet of the temperature and pressure reducing device; And the water supply diverter valve is used for controlling the on-off between the water working medium outlet of the deaerator and the inlet end of the second channel and controlling the on-off between the water working medium outlet of the deaerator and the liquid inlet.
5. The high-pressure steam supply system for coupling molten salt heat storage according to claim 4, wherein the high-pressure steam supply system for coupling molten salt heat storage has a normal mode, a low load mode and a high load mode, In the normal mode, the main steam diverter valve is closed, the reheat steam diverter valve is in communication with the feedwater diverter valve; In the low-load mode, the main steam diverter valve is communicated with the feedwater diverter valve, the reheat steam diverter valve is closed, and the molten salt electric heater and the low-temperature molten salt pump are opened; in the high load mode, the main steam diverter valve is closed, the reheat steam diverter valve is communicated with the feedwater diverter valve, and the high temperature molten salt pump is opened.
6. The coupled molten salt heat storage high pressure steam supply system of claim 1 wherein the steam flow at the outlet end of the primary steam diverter valve is no more than 21% of the steam flow at the primary steam outlet; and/or the steam flow of the outlet end of the reheat steam diverter valve is not more than 23% of the steam flow at the steam outlet of the primary reheat intermediate reheater; and/or the range of the exhaust back pressure of the back press is 4.3MPa-4.5MPa.
7. The high-pressure steam supply system for coupling molten salt heat storage according to claim 1, wherein the coal-fired unit further comprises a steam turbine medium-pressure cylinder, a steam turbine low-pressure cylinder, a generator, a condenser, a condensate pump, a low-pressure heater, a deaerator, a water supply pump and a high-pressure heater, The steam extraction outlet of the turbine ultrahigh pressure cylinder is connected with the steam inlet of the high pressure heater, the steam outlet of the turbine high pressure cylinder is connected with the steam inlet of the secondary reheater of the boiler, the steam outlet of the secondary reheater is connected with the steam inlet of the turbine medium pressure cylinder, the steam extraction outlet of the turbine medium pressure cylinder is connected with the steam inlet of the deaerator, the steam outlet of the turbine medium pressure cylinder is connected with the steam inlet of the turbine low pressure cylinder, the steam extraction outlet of the turbine low pressure cylinder is connected with the steam inlet of the low pressure heater, the steam outlet of the turbine low pressure cylinder is connected with the steam inlet of the condenser, the water outlet of the condenser is connected with the water inlet of the low pressure heater through a condensate pump, the water outlet of the low pressure heater is connected with the water inlet of the deaerator through the pump, the water outlet of the high pressure heater is connected with the water inlet of the high pressure heater, and the turbine low pressure cylinder is connected with the steam generator through the turbine high pressure cylinder, the turbine high pressure cylinder and the steam generator.

Description

High-pressure steam supply system for coupling fused salt heat storage Technical Field The invention relates to the technical field of coal-fired power generation, in particular to a high-pressure steam supply system for coupling molten salt heat storage. Background In the related art, the installed capacity of renewable energy sources such as wind power, photovoltaic and the like is improved year by year. The renewable energy power generation output has strong time variability, and large-scale renewable energy power grid connection causes huge peak-valley difference for a power grid supply end, and simultaneously causes adverse effects on the stability of the power grid maintenance frequency. In order to ensure safe and stable operation of the power system under high-proportion renewable energy permeation, the coal-fired power generator set needs to exert good load regulation performance. Meanwhile, the coal-fired generator set is a main central heating and industrial heating source for towns. The power grid peak regulation task is completed while heat supply is guaranteed, and the reduction of wind and light waste is an important challenge for a coal-fired power generation unit. When the coal-fired unit is provided with a heating load, the coal-fired unit is limited by the minimum stable combustion load of the boiler, the minimum cooling flow of the steam turbine and other safe operation boundaries, and the deep peak regulation capacity of the unit is reduced. When the high-pressure industrial steam supply load is carried out, the risk that the steam supply parameters cannot be ensured exists under the low load in the fixed-sliding-fixed operation mode of the coal-fired unit, and the high-quality energy waste can be caused only by extracting the steam with higher parameters to reduce the temperature and the pressure. Disclosure of Invention The present invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the invention provides the high-pressure steam supply system for coupling molten salt heat storage, which can realize energy cascade utilization, reduce the station service power of a unit and effectively improve the peak regulation capacity of the unit. The high-pressure steam supply system for coupling molten salt heat storage comprises a coal-fired unit and a high-pressure steam supply system. The high-pressure steam supply system comprises a back press, and the coal-fired unit comprises a boiler, a turbine ultrahigh pressure cylinder, a turbine high pressure cylinder, a main steam diverter valve and a reheat steam diverter valve. The boiler is provided with a main steam outlet, the main steam outlet is communicated with a steam inlet of the back press, a primary reheating intermediate reheater and a primary reheating secondary reheater are arranged in the boiler, the primary reheating intermediate reheater steam outlet is respectively communicated with the steam inlet of the primary reheating secondary reheater and the steam inlet of the back press, the main steam outlet is communicated with a steam inlet of the turbine ultrahigh pressure cylinder, the steam outlet of the turbine ultrahigh pressure cylinder is communicated with the steam inlet of the primary reheating intermediate reheater, the steam outlet of the primary reheating secondary reheater is communicated with the steam inlet of the turbine high pressure cylinder, the main steam diverter valve is used for controlling the on-off between the main steam outlet and the steam inlet of the back press, and the reheating steam diverter valve is used for controlling the on-off between the primary reheating intermediate reheater steam outlet and the steam inlet of the back press. According to the high-pressure steam supply system for coupling molten salt heat storage, the back press is arranged in the high-pressure steam supply system, the primary reheating intermediate reheater and the primary reheating secondary reheater are arranged in the boiler, the steam outlet of the primary reheating intermediate reheater is respectively communicated with the steam inlet of the primary reheating secondary reheater and the steam inlet of the back press, and the main steam diverter valve for controlling on-off between the main steam outlet and the steam inlet of the back press is arranged and used for controlling the on-off between the steam outlet of the primary reheating intermediate reheater and the steam inlet of the back press, so that energy cascade utilization can be realized, the plant power of a unit is reduced, and the peak regulation capacity of the unit is effectively improved. According to some embodiments of the invention, the coal-fired unit further comprises a steam turbine medium pressure cylinder and a deaerator, a steam extraction outlet of the steam turbine medium pressure cylinder is communicated with a steam inlet of the deaerator, a water working medium outlet of the deaerator is communicate