CN118601696A - Flue gas carbon capture steam supply system and method for improving peak load regulation capability - Google Patents

Abstract

The present invention provides a flue gas carbon capture steam supply system and method for improving peak shaving capability, and relates to the technical field of coal-fired power generation. The flue gas carbon capture steam supply system is connected to the flue gas carbon capture system and the thermal power unit; the thermal power unit can deliver reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system; the flue gas carbon capture steam supply system includes: a high-temperature energy storage device, which is respectively connected to the flue gas carbon capture system and the thermal power unit; it is used to obtain and store the heat energy of the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam delivered by the thermal power unit, and use the stored heat energy to heat the condensate from the thermal power unit to generate the first high-temperature steam and deliver it to the flue gas carbon capture system. The flue gas carbon capture steam supply system and method for improving peak shaving capability solve the problem in the prior art that the load of the carbon capture system changes with the load of the thermal power unit, thereby affecting the auxiliary service capacity of the thermal power unit, and broadens the peak shaving range of the carbon capture thermal power unit.

Description

Flue gas carbon capture steam supply system and method for improving peak load regulation capability

Technical Field

The present invention relates to the technical field of coal-fired power generation, and in particular to a flue gas carbon capture steam supply system for improving peak-shaving capability and a flue gas carbon capture steam supply method for improving peak-shaving capability.

Background Art

Chemical absorption is currently the only carbon capture technology that can be applied on a large scale. Existing thermal power chemical absorption carbon capture systems usually need to extract steam from the thermal system of the thermal power unit for rich liquid regeneration, and consume electricity for capture, compression and liquefaction. With the approach of the dual carbon goals, high-proportion or even full flue gas carbon capture in thermal power is imperative. However, the demand for deep peak regulation of thermal power is increasing. Carbon capture thermal power units consume electricity and steam, which affects the peak capacity of thermal power units. Especially for high-proportion or even full flue gas carbon capture units, thermal power and carbon capture systems are deeply coupled, and the load of the carbon capture system needs to change with the load of the thermal power unit. When the thermal power unit is at full load, carbon capture also needs to consume electricity and steam at full load, which seriously affects the auxiliary service capacity of the thermal power unit.

Therefore, there is an urgent need for a device that can solve at least one of the above problems.

Summary of the invention

The purpose of the embodiments of the present invention is to provide a flue gas carbon capture steam supply system and method with improved peak load regulation capability, so as to solve the problem in the prior art that the load of the carbon capture system follows the load changes of the thermal power unit and thus affects the auxiliary service capacity of the thermal power unit.

In order to achieve the above-mentioned object, the present invention provides, on one hand, a flue gas carbon capture steam supply system for improving peak load regulation capability, wherein the flue gas carbon capture steam supply system is connected to a flue gas carbon capture system and a thermal power unit;

The thermal power unit is capable of delivering reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system and delivering medium-pressure exhaust steam to the flue gas carbon capture system;

The flue gas carbon capture steam supply system includes: a high-temperature energy storage device, which is respectively connected to the flue gas carbon capture system and the thermal power unit; the high-temperature energy storage device is used to obtain and store the thermal energy of the reheated hot section steam, the reheated cold section steam and/or the medium-pressure exhaust steam transmitted by the thermal power unit, and use the stored thermal energy to heat the condensate from the thermal power unit to generate the first high-temperature steam and transmit it to the flue gas carbon capture system.

Specifically, the high-temperature energy storage device includes: a high-temperature molten salt heat storage tank, a low-temperature molten salt heat storage tank, a first heat exchange component and a second heat exchange component;

The high-temperature molten salt heat storage tank, the first heat exchange component, the low-temperature molten salt heat storage tank and the second heat exchange component are connected in sequence by pipelines;

The high-temperature molten salt heat storage tank stores liquid salt, and the high-temperature molten salt heat storage tank has a high-temperature inlet and a high-temperature outlet. The high-temperature molten salt heat storage tank obtains and stores the heat energy of the reheated hot section steam, the reheated cold section steam and/or the medium-pressure exhaust steam of the thermal power unit through the liquid salt. The liquid salt after obtaining the heat energy becomes high-temperature liquid salt, and the high-temperature liquid salt is output by the high-temperature molten salt heat storage tank;

The low-temperature molten salt heat storage tank has a low-temperature inlet and a low-temperature outlet, the low-temperature inlet of the low-temperature molten salt heat storage tank is connected to the high-temperature outlet of the high-temperature molten salt heat storage tank through a pipeline, the low-temperature outlet of the low-temperature molten salt heat storage tank is connected to the high-temperature inlet of the high-temperature molten salt heat storage tank through a pipeline, and the low-temperature molten salt heat storage tank is used to store and output high-temperature liquid salt after heat loss, wherein the high-temperature liquid salt after heat loss is low-temperature liquid salt;

The first heat exchange component is arranged on a pipeline between a low-temperature inlet of the low-temperature molten salt heat storage tank and a high-temperature outlet of the high-temperature molten salt heat storage tank, and is connected to the flue gas carbon capture system. The first heat exchange component uses the high-temperature liquid salt output by the high-temperature molten salt heat storage tank to exchange heat with condensed water from the thermal power unit to generate first high-temperature steam, and transports the first high-temperature steam to the flue gas carbon capture system;

The second heat exchange component is arranged on the pipeline between the low-temperature outlet of the low-temperature molten salt heat storage tank and the high-temperature inlet of the high-temperature molten salt heat storage tank, and is connected to the thermal power unit. The second heat exchange component uses the low-temperature liquid salt output by the low-temperature molten salt heat storage tank to exchange heat with the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam from the thermal power unit. The low-temperature liquid salt absorbs the heat energy of the reheat hot section steam, the reheat cold section steam and/or the medium-pressure exhaust steam to become high-temperature liquid salt and store it in the high-temperature molten salt heat storage tank.

Specifically, the first heat exchange component includes: a first heat exchange pipeline and a first evaporator and a first preheater sequentially arranged on the pipeline between the high-temperature outlet and the low-temperature inlet;

One end of the first heat exchange pipeline is connected to the flue gas carbon capture system, and the other end is connected to the pipeline between the first evaporator and the high-temperature molten salt heat storage tank;

The high-temperature liquid salt output from the high-temperature molten salt heat storage tank flows through the first evaporator and the first preheater in sequence, and the condensed water flows through the first preheater and the first evaporator in sequence. The high-temperature liquid salt and the condensed water are heat exchanged in the first preheater and the first evaporator respectively. The high-temperature liquid salt after losing heat becomes low-temperature liquid salt and enters the low-temperature molten salt heat storage tank. The condensed water becomes the first high-temperature steam after being heated and is transported to the flue gas carbon capture system through the first heat exchange pipeline.

Specifically, the first heat exchange component also includes: a first superheater, which is arranged on the pipeline between the high-temperature outlet and the first evaporator, and the first superheater uses the high-temperature liquid salt output by the high-temperature molten salt heat storage tank to perform heat exchange with the first high-temperature steam to generate and output superheated steam.

Specifically, the second heat exchange assembly includes: a second subcooling heat exchanger, a second condensing heat exchanger and a second superheating heat exchanger which are sequentially arranged on the pipeline between the low-temperature outlet and the high-temperature inlet;

The low-temperature liquid salt output from the low-temperature molten salt heat storage tank flows through the second subcooling heat exchanger, the second condensing heat exchanger and the second superheating heat exchanger in sequence, and the reheated hot section steam and/or the reheated cold section steam from the thermal power unit flows through the second superheating heat exchanger, the second condensing heat exchanger and the second subcooling heat exchanger in sequence. The low-temperature liquid salt and the reheated hot section steam and/or the reheated cold section steam from the thermal power unit are heat exchanged in the second superheating heat exchanger, the second condensing heat exchanger and the second subcooling heat exchanger respectively. The low-temperature liquid salt after gaining heat becomes high-temperature liquid salt and is transported to the high-temperature molten salt heat storage tank, and the reheated hot section steam and/or the reheated cold section steam after losing heat are sent back to the thermal power unit.

Specifically, the flue gas carbon capture steam supply system also includes: a second steam supply bypass pipe, one end of which is connected to the flue gas carbon capture system, and the other end is connected to the pipe between the second condensing heat exchanger and the second superheat heat exchanger, and the second steam supply bypass pipe is used to transport the reheat hot section steam and/or reheat cold section steam that loses heat in the second superheat heat exchanger to the flue gas carbon capture system.

Specifically, the flue gas carbon capture steam supply system also includes: a third superheat heat exchanger, which is connected to the low-temperature molten salt heat storage tank, the second heat exchange component, the thermal power unit and the flue gas carbon capture system through a pipeline. The third superheat heat exchanger uses the medium-pressure exhaust steam provided by the thermal power unit to exchange heat with the low-temperature liquid salt output by the low-temperature molten salt heat storage tank to preheat the low-temperature liquid salt. The medium-pressure exhaust steam after losing heat is transported to the flue gas carbon capture system.

Specifically, the flue gas carbon capture auxiliary system also includes: an external steam supply manifold, which is connected to the thermal power unit, the first superheater and the second steam supply bypass pipeline through a pipeline, and the external steam supply manifold is used to recover the reheat cold section steam delivered by the thermal power unit, the superheated steam, and the reheat hot section steam and/or reheat cold section steam that loses heat in the second superheat heat exchanger and flows through the second steam supply bypass pipeline to become mixed steam, and use the mixed steam as a heat source to supply heat to the outside.

Another aspect of the present invention provides a flue gas carbon capture steam supply method for improving peak load regulation capability, which is implemented based on any of the flue gas carbon capture steam supply systems for improving peak load regulation capability described above, and the flue gas carbon capture steam supply method comprises:

The thermal energy of the reheated hot section steam, reheated cold section steam and/or medium pressure exhaust steam transmitted by the thermal power unit is obtained and stored through a high temperature energy storage device, and the stored thermal energy is used to heat the condensate from the thermal power unit to generate the first high temperature steam and transmit it to the flue gas carbon capture system.

Specifically, the high-temperature energy storage device obtains and stores the thermal energy of the reheated hot section steam, reheated cold section steam and/or medium-pressure exhaust steam of the thermal power unit through the liquid salt stored in the high-temperature molten salt heat storage tank.

The flue gas carbon capture steam supply system with improved peak load regulation capability provided by the present invention transmits reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system through the thermal power unit, obtains and stores the heat energy of the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam through the high-temperature energy storage device, and uses the stored heat energy to heat condensate to become the first high-temperature steam to be transmitted to the flue gas carbon capture system, thereby increasing the steam supply route of the flue gas carbon capture system and ensuring the stable operation of the high-proportion flue gas carbon capture system. When the thermal power unit is at its peak, the heat energy stored in the high-temperature energy storage device heats the condensate to become the first high-temperature steam to be transmitted to the flue gas carbon capture system. The system stores the heat energy of the reheat hot section steam, reheat cold section steam and/or medium pressure exhaust steam of the thermal power unit through the high temperature energy storage device when the thermal power unit is in the valley of pressure. In this way, the load of the thermal power unit changes, and the steam supply mode transmitted to the flue gas carbon capture system is adjusted accordingly, thereby improving the flexibility and flue gas carbon capture efficiency of the flue gas carbon capture steam supply system, and also improving the auxiliary service capacity of the thermal power unit. The flue gas carbon capture steam supply system and method with improved peak shaving capacity provided by the present invention solve the problem in the prior art that the load of the carbon capture system changes with the load of the thermal power unit and thus affects the auxiliary service capacity of the thermal power unit, and broadens the peak shaving range of the carbon capture thermal power unit.

Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

FIG1 is a schematic diagram of the layout of a flue gas carbon capture steam supply system for improving peak load regulation capability provided by the present invention.

Description of Reference Numerals

1-Flue gas carbon capture system; 2-thermal power unit; 3-high-temperature energy storage device; 4-second steam supply bypass pipeline; 5-third superheat heat exchanger; 6-external steam supply manifold; 7-condenser; 8-low-pressure heater; 9-first pump; 10-high-pressure heater; 12-second pump 31-high-temperature molten salt heat storage tank; 32-low-temperature molten salt heat storage tank; 33-first heat exchange component; 34-second heat exchange component; 331-first superheater; 332-first evaporator; 333-first preheater; 334-first heat exchange pipeline; 341-second subcooling heat exchanger; 342-second condensing heat exchanger; 343-second superheat heat exchanger.

DETAILED DESCRIPTION

The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

Figure 1 is a schematic diagram of the layout of a flue gas carbon capture steam supply system for improving peak load regulation capability. As shown in Figure 1, the present invention provides a flue gas carbon capture steam supply system for improving peak load regulation capability, wherein the flue gas carbon capture steam supply system is connected to a flue gas carbon capture system 1 and a thermal power unit 2;

The thermal power unit 2 is capable of delivering reheated hot section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system and delivering medium-pressure exhaust steam to the flue gas carbon capture system 1;

The flue gas carbon capture steam supply system includes: a high-temperature energy storage device 3, which is respectively connected to the flue gas carbon capture system 1 and the thermal power unit 2; the high-temperature energy storage device 3 is used to obtain and store the thermal energy of the reheated hot section steam, the reheated cold section steam and/or the medium-pressure exhaust steam delivered by the thermal power unit 2, and use the stored thermal energy to heat the condensate from the thermal power unit 2 to generate the first high-temperature steam and deliver it to the flue gas carbon capture system 1.

The flue gas carbon capture steam supply system with improved peak load regulation capability provided by the present invention is capable of transmitting reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system, and directly transmitting medium-pressure exhaust steam to the flue gas carbon capture system 1. When the thermal power unit is at a low pressure valley, the thermal energy of the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam of the thermal power unit 1 is stored by the high-temperature energy storage device 3. When the thermal power unit 2 is at a peak, the high-temperature energy storage device 3 uses the stored thermal energy to heat the condensate from the thermal power unit 2 to become the first high-temperature steam, which is transmitted to the flue gas carbon capture system. 1 is used to supply the flue gas carbon capture system 1 with rich liquid for regeneration. Thus, when the load of the thermal power unit 2 changes, the steam supply mode for the flue gas carbon capture system 1 changes accordingly, thereby improving the flexibility of the flue gas carbon capture steam supply system for improving the peak-shaving capability and the flue gas carbon capture efficiency, and also improving the auxiliary service capability of the thermal power unit 2. The flue gas carbon capture steam supply system and method for improving the peak-shaving capability provided by the present invention solve the problem in the prior art that the load of the carbon capture system changes with the load of the thermal power unit and thus affects the auxiliary service capability of the thermal power unit, thereby broadening the peak-shaving range of the carbon capture thermal power unit.

In one embodiment, as shown in FIG1 , the high temperature energy storage device 3 includes: a high temperature molten salt heat storage tank 31 , a low temperature molten salt heat storage tank 32 , a first heat exchange component 33 and a second heat exchange component 34 ;

The high-temperature molten salt heat storage tank 31, the first heat exchange component 33, the low-temperature molten salt heat storage tank 32 and the second heat exchange component 34 are connected in sequence by pipelines;

The high-temperature molten salt heat storage tank 31 stores liquid salt. The high-temperature molten salt heat storage tank 31 has a high-temperature inlet and a high-temperature outlet. The high-temperature molten salt heat storage tank 31 obtains and stores the heat energy of the reheated hot section steam, the reheated cold section steam and/or the medium-pressure exhaust steam of the thermal power unit 2 through the liquid salt. The liquid salt after obtaining the heat energy becomes high-temperature liquid salt, and the high-temperature liquid salt is output by the high-temperature molten salt heat storage tank 31;

The low-temperature molten salt heat storage tank 32 has a low-temperature inlet and a low-temperature outlet. The low-temperature inlet of the low-temperature molten salt heat storage tank 32 is connected to the high-temperature outlet of the high-temperature molten salt heat storage tank 31 through a pipeline, and the low-temperature outlet of the low-temperature molten salt heat storage tank 32 is connected to the high-temperature inlet of the high-temperature molten salt heat storage tank 31 through a pipeline. The low-temperature molten salt heat storage tank 32 is used to store and output high-temperature liquid salt after heat loss, wherein the high-temperature liquid salt after heat loss is low-temperature liquid salt;

The first heat exchange component 33 is arranged on a pipeline between the low-temperature inlet of the low-temperature molten salt heat storage tank 32 and the high-temperature outlet of the high-temperature molten salt heat storage tank 31, and is connected to the flue gas carbon capture system 1. The first heat exchange component 33 uses the high-temperature liquid salt output by the high-temperature molten salt heat storage tank 31 to perform heat exchange with the condensed water from the thermal power unit 2 to generate first high-temperature steam, and transports the first high-temperature steam to the flue gas carbon capture system 1;

The second heat exchange component 34 is arranged on the pipeline between the low-temperature outlet of the low-temperature molten salt heat storage tank 32 and the high-temperature inlet of the high-temperature molten salt heat storage tank 31, and is connected to the thermal power unit. The second heat exchange component 34 uses the low-temperature liquid salt output by the low-temperature molten salt heat storage tank 32 to exchange heat with the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam from the thermal power unit. The low-temperature liquid salt absorbs the heat energy of the reheat hot section steam, the reheat cold section steam and/or the medium-pressure exhaust steam to become high-temperature liquid salt and is stored in the high-temperature molten salt heat storage tank 31.

The first heat exchange component 33 includes: a first heat exchange pipe 334 and a first evaporator 332 and a first preheater 333 sequentially arranged on the pipe between the high temperature outlet and the low temperature inlet;

One end of the first heat exchange pipe 334 is connected to the flue gas carbon capture system 1, and the other end is connected to the pipe between the first evaporator 332 and the high-temperature molten salt heat storage tank 31;

The high-temperature liquid salt output from the high-temperature molten salt heat storage tank 31 flows through the first evaporator 332 and the first preheater 333 in sequence, and the condensed water flows through the first preheater 333 and the first evaporator 332 in sequence. The high-temperature liquid salt and the condensed water are heat exchanged in the first preheater 333 and the first evaporator 332 respectively. The high-temperature liquid salt after losing heat becomes low-temperature liquid salt and enters the low-temperature molten salt heat storage tank 32. The condensed water becomes the first high-temperature steam after being heated and is transported to the flue gas carbon capture system 1 through the first heat exchange pipeline.

The first heat exchange component 33 also includes: a first superheater 331, which is arranged on the pipeline between the high-temperature outlet and the first evaporator 332. The first superheater 331 uses the high-temperature liquid salt output by the high-temperature molten salt heat storage tank 31 to perform heat exchange with the first high-temperature steam to generate and output superheated steam.

The second heat exchange assembly 34 includes: a second subcooling heat exchanger 341, a second condensing heat exchanger 342 and a second superheating heat exchanger 343 which are sequentially arranged on the pipeline between the low-temperature outlet and the high-temperature inlet;

The low-temperature liquid salt output from the low-temperature molten salt heat storage tank 32 flows through the second subcooling heat exchanger 341, the second condensing heat exchanger 342 and the second superheating heat exchanger 343 in sequence, and the reheated hot section steam and/or reheated cold section steam from the thermal power unit 2 flows through the second superheating heat exchanger 343, the second condensing heat exchanger 342 and the second subcooling heat exchanger 341 in sequence, and the low-temperature liquid salt and the reheated hot section steam and/or reheated cold section steam from the thermal power unit 2 are heat exchanged in the second superheating heat exchanger 343, the second condensing heat exchanger 342 and the second subcooling heat exchanger 341 respectively, to obtain The heated low-temperature liquid salt becomes high-temperature liquid salt and is transported to the high-temperature molten salt heat storage tank 31, and the reheated hot section steam after losing heat is sent back to the thermal power unit 2. In order to adjust the pressure and flow of the reheated hot section steam and/or the reheated cold section steam entering the second superheat heat exchanger 343, a hot section regulating valve is arranged on the reheated hot section steam pipeline from the thermal power unit 2, and the pressure and flow of the reheated hot section steam entering the second superheat heat exchanger 343 are adjusted by the hot section regulating valve, and a cold section regulating valve is arranged on the reheated cold section steam pipeline from the thermal power unit 2, and the pressure and flow of the reheated cold section steam entering the second superheat heat exchanger 343 are adjusted by the cold section regulating valve.

The high-temperature molten salt heat storage tank 31 can store liquid salt and high-temperature liquid salt. The liquid salt becomes high-temperature liquid salt after obtaining the heat energy of the reheated hot section steam, the reheated cold section steam and/or the medium-pressure exhaust steam of the thermal power unit 2. When the thermal power unit 2 is at the top peak, the high-temperature liquid salt in the high-temperature molten salt heat storage tank 31 flows out from the high-temperature outlet and flows through the first superheater 331, the first evaporator 332 and the first preheater 333 in sequence. The condensed water from the thermal power unit 2 flows through the first preheater 333, the first evaporator 332 and the first preheater 333 in sequence. 332 and the first superheater 331, the high-temperature liquid salt and the condensed water are heat exchanged in the first preheater 333, the first evaporator 332 and the first superheater 331. The temperature of the high-temperature liquid salt gradually decreases during the process of flowing through the first superheater 331, the first evaporator 332 and the first preheater 333 in sequence, while the temperature of the condensed water gradually increases during the process of flowing through the first preheater 333, the first evaporator 332 and the first superheater 331 in sequence. In order to be able to send the condensed water of the thermal power unit 2 to the first preheater 333, a condensate pump and a condensate regulating valve are arranged on the condensate inlet pipe, the condensate pump of the thermal power unit 2 can be quickly pumped to the first preheater 333, and the condensate regulating valve is used to adjust the water pressure and flow rate of the condensate entering the first preheater 333, after the condensate flows out of the first evaporator 332, it absorbs the heat of the high-temperature liquid salt and becomes the first high-temperature steam, the first high-temperature steam is divided into two paths, one of which is transported to the flue gas carbon capture system 1 through the first heat exchange pipe 334 to be heated to the flue gas carbon capture system 1. For rich liquid regeneration, the other first high-temperature steam enters the first superheater 331 for heat exchange with the high-temperature liquid salt flowing out of the high-temperature molten salt heat storage tank 31. The high-temperature liquid salt flowing out of the high-temperature molten salt heat storage tank 31 has the highest temperature. After the first high-temperature steam absorbs the heat of the high-temperature liquid salt in the first superheater 331, its temperature rises again to become superheated steam. The superheated steam is recovered through the external steam supply manifold 6, making the superheated steam a heat source for external heating. At the same time, the superheated steam can also be transported to the thermal power unit 2 for use. The high-temperature liquid salt undergoes heat exchange with condensed water in the first preheater 333 to become low-temperature liquid salt, and the low-temperature liquid salt enters the low-temperature molten salt heat storage tank 32 through a pipeline. When the thermal power unit 2 is at a low pressure valley, the thermal power unit 2 provides the high-temperature energy storage device 3 with reheated hot section steam and/or reheated cold section steam, and the reheated hot section steam and/or reheated cold section steam flow through the second superheat heat exchanger 343, the second condensing heat exchanger 342 and the second subcooling heat exchanger 341 in sequence, and the low-temperature liquid salt discharged from the low-temperature outlet of the low-temperature molten salt heat storage tank 32 flows through the second subcooling heat exchanger 341, the second condensing heat exchanger 342 and the second superheat heat exchanger 343 in sequence, and the reheated hot section steam and/or reheated cold section steam and the low-temperature liquid The low-temperature liquid salt exchanges heat in the second subcooling heat exchanger 341, the second condensing heat exchanger 342 and the second superheating heat exchanger 343, so that the temperature of the reheated hot section steam and/or the reheated cold section steam gradually decreases during the process of flowing through the second superheating heat exchanger 343, the second condensing heat exchanger 342 and the second subcooling heat exchanger 341 in sequence, while the temperature of the low-temperature liquid salt gradually increases during the process of flowing through the second subcooling heat exchanger 341, the second condensing heat exchanger 342 and the second superheating heat exchanger 343 in sequence. After flowing out of the second superheating heat exchanger 343, the low-temperature liquid salt fully absorbs the heat of the reheated hot section steam and/or the reheated cold section steam, and the low-temperature liquid salt becomes high-temperature liquid salt and is transported to the high-temperature molten salt heat storage tank 31.

As shown in Figure 1, in order to avoid the reheat hot section steam and/or reheat cold section steam having too high a temperature when sent into the flue gas carbon capture system 1 to affect the rich liquid regeneration effect, the flue gas carbon capture steam supply system also includes: a second steam supply bypass pipe 4, one end of which is connected to the flue gas carbon capture system 1, and the other end is connected to the pipe between the second condensing heat exchanger 342 and the second superheat heat exchanger 343, and the second steam supply bypass pipe 4 is used to transport the reheat hot section steam and/or reheat cold section steam that has lost heat in the second superheat heat exchanger 343 to the flue gas carbon capture system 1. The reheated hot section steam and/or reheated cold section steam are heat exchanged with the low temperature liquid salt through the second superheat heat exchanger 343, thereby reducing the temperature of the reheated hot section steam and/or reheated cold section steam entering the flue gas carbon capture system 1. It is defined that the reheated hot section steam and/or reheated cold section steam lose heat and become the second high temperature steam after heat exchange with the low temperature liquid salt in the second superheat heat exchanger 343. The second high temperature steam is transported to the flue gas carbon capture system 1 through the second steam supply bypass pipeline 4 for rich liquid regeneration. In order to improve the energy utilization rate, a pipeline is set to connect the second steam supply bypass pipeline 4 with the external steam supply manifold 6, so that the excess second high temperature steam can be transported to the external steam supply manifold 6, and the second high temperature steam can be used as a heat source for external heating.

As shown in FIG1 , the thermal power unit 1 includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder and a pair of low-pressure cylinders. The intermediate-pressure exhaust steam is the exhaust steam from the intermediate-pressure cylinder, the reheated hot section steam comes from the boiler, and the reheated cold section steam comes from the high-pressure cylinder exhaust steam. In order to improve the energy utilization rate, the high-pressure exhaust steam discharged from the high-pressure cylinder is transported in two ways, one way enters the boiler for reheating to become the reheated hot section steam and is discharged from the boiler, and the other way is the reheated cold section steam sent to the second superheat heat exchanger 343 for heat exchange with the low-temperature liquid salt flowing through the second superheat heat exchanger 343, thereby obtaining the thermal energy of the reheated cold section steam, and the superheated steam discharged from the first superheater 331 can also be sent to the boiler of the thermal power unit 2 for reheating. The reheated hot section steam discharged from the boiler is transported in two ways, one way is sent to the second superheat heat exchanger 343 for heat exchange with the low-temperature liquid salt flowing through the second superheat heat exchanger 343, and the other way is the reheated hot section steam sent to the intermediate-pressure cylinder for the intermediate-pressure cylinder to do work. The medium-pressure exhaust steam is transported in three ways, one way enters the low-pressure cylinder, another way is sent to the third superheat heat exchanger 5, and the other way is directly sent to the flue gas carbon capture system 1. A butterfly valve is set on the pipeline of the medium-pressure exhaust steam entering the low-pressure cylinder to control the flow state of the medium-pressure exhaust steam in the corresponding pipeline through the butterfly valve. A control valve is set on the pipeline of the medium-pressure exhaust steam entering the flue gas carbon capture system 1 to control the flow state of the medium-pressure exhaust steam in the pipeline. The low-pressure cylinder exhaust steam flows through the condenser 7 and the low-pressure heater 8, and the low-pressure cylinder exhaust steam is condensed into water by the condenser 7. The low-pressure heater 8 heats the water to become condensed water. The condensed water discharged from the low-pressure heater 8 is divided into two ways, one way is transported to the first preheater 333, and the other way is first transported to the deaerator for purification. The purified condensed water is pumped to the high-pressure heater 10 by the first pump 9, and is sent to the boiler after being heated and pressurized by the high-pressure heater 10. The first high-temperature steam sent to the carbon capture system 1, the reheated hot section steam and/or recooling section steam that loses heat in the second superheat heat exchanger 343, the medium-pressure exhaust steam, and the medium-pressure exhaust steam after losing heat lose heat and become capture wastewater after completing rich liquid regeneration in the flue gas carbon capture system 1 and are discharged from the carbon capture system 1. The discharged capture wastewater is pumped by the second pump 12 to the low-pressure heater 8 as a source of condensate.

In order to improve the utilization rate of the medium-pressure exhaust steam provided by the thermal power unit 2, the flue gas carbon capture steam supply system also includes: a third superheat heat exchanger 5, which is connected to the low-temperature molten salt heat storage tank 32, the second heat exchange component 34, the thermal power unit 2 and the flue gas carbon capture system 1 through a pipeline. The third superheat heat exchanger 5 uses the medium-pressure exhaust steam provided by the thermal power unit 2 to exchange heat with the low-temperature liquid salt output by the low-temperature molten salt heat storage tank 32 to preheat the low-temperature liquid salt. The medium-pressure exhaust steam after losing heat is transported to the flue gas carbon capture system 1. The medium-pressure exhaust steam provided by the medium-pressure cylinder of the steam turbine of the thermal power unit 2 enters the third superheat heat exchanger 5, and the low-temperature liquid salt discharged from the low-temperature molten salt heat storage tank 32 flows through the third superheat heat exchanger 5. The low-temperature liquid salt exchanges heat with the medium-pressure exhaust steam in the third superheat heat exchanger 5, and the low-temperature liquid salt is preheated by the medium-pressure exhaust steam. The preheated low-temperature liquid salt flows through the second condensing heat exchanger 342 and the second superheat heat exchanger 343 in sequence. The medium-pressure exhaust steam after heat loss is sent to the flue gas carbon capture system 1 for rich liquid regeneration. The medium-pressure exhaust steam of the medium-pressure cylinder can also be directly sent to the flue gas carbon capture system 1 for rich liquid regeneration through a pipeline.

In order to improve the energy utilization rate, the flue gas carbon capture auxiliary system also includes: an external steam supply manifold 6, which is connected to the thermal power unit 2, the first superheater 331 and the second steam supply bypass pipeline 4 through a pipeline, and the external steam supply manifold 6 is used to recover the reheat cold section steam of the thermal power unit 2, the superheated steam, and the reheat hot section steam and/or reheat cold section steam that loses heat in the second superheat heat exchanger 343 flowing through the second steam supply bypass pipeline 4 to form mixed steam, and the mixed steam is used as a heat source for external heat supply. As shown in Figure 1, in actual application, the reheat cold section steam, the second high temperature steam and the superheated steam discharged from the high pressure cylinder are recovered by the external steam supply manifold 6, and the reheat cold section steam, the second high temperature steam and the superheated steam of the high pressure cylinder collected in the external steam supply manifold 6 are mixed in the external steam supply manifold 6 to form mixed steam, and the mixed steam can be used as a heat source for external heat supply.

Another aspect of the present invention provides a flue gas carbon capture steam supply method for improving peak load regulation capability, which is implemented based on any of the flue gas carbon capture steam supply systems for improving peak load regulation capability described above, and the flue gas carbon capture steam supply method comprises:

The thermal energy of the reheated hot section steam, reheated cold section steam and/or medium-pressure exhaust steam delivered by the thermal power unit 2 is obtained and stored through the high-temperature energy storage device 3, and the stored thermal energy is used to heat the condensate from the thermal power unit 2 to generate the first high-temperature steam and deliver it to the flue gas carbon capture system 1.

Specifically, the high-temperature energy storage device 3 obtains and stores the thermal energy of the reheated hot section steam, reheated cold section steam and/or medium-pressure exhaust steam of the thermal power unit 2 through the liquid salt stored in the high-temperature molten salt heat storage tank 31.

The flue gas carbon capture steam supply system with improved peak load regulation capability provided by the present invention transmits reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system through the thermal power unit, obtains and stores the heat energy of the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam through the high-temperature energy storage device, and uses the stored heat energy to heat condensate to become the first high-temperature steam to be transmitted to the flue gas carbon capture system, thereby increasing the steam supply route of the flue gas carbon capture system and ensuring the stable operation of the high-proportion flue gas carbon capture system. When the thermal power unit is at its peak, the heat energy stored in the high-temperature energy storage device heats the condensate to become the first high-temperature steam to be transmitted to the flue gas carbon capture system. The system stores the heat energy of the reheat hot section steam, reheat cold section steam and/or medium pressure exhaust steam of the thermal power unit through the high temperature energy storage device when the thermal power unit is in the valley of pressure. In this way, the load of the thermal power unit changes, and the steam supply mode transmitted to the flue gas carbon capture system is adjusted accordingly, thereby improving the flexibility and flue gas carbon capture efficiency of the flue gas carbon capture steam supply system, and also improving the auxiliary service capacity of the thermal power unit. The flue gas carbon capture steam supply system and method with improved peak shaving capacity provided by the present invention solve the problem in the prior art that the load of the carbon capture system changes with the load of the thermal power unit and thus affects the auxiliary service capacity of the thermal power unit, and broadens the peak shaving range of the carbon capture thermal power unit.

The optional implementation modes of the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation modes. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical scheme of the embodiments of the present invention, and these simple modifications all belong to the protection scope of the embodiments of the present invention.

It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

In addition, various implementations of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims (10)

1. The flue gas carbon trapping and steam supplying system for improving peak regulation capability is characterized in that the flue gas carbon trapping and steam supplying system is connected with a flue gas carbon trapping system (1) and a thermal power generating unit (2);

The thermal power generating unit (2) can convey reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to the flue gas carbon capture steam supply system and convey medium-pressure exhaust steam to the flue gas carbon capture system (1);

The flue gas carbon capture steam supply system comprises: the high-temperature energy storage device (3) is respectively connected with the flue gas carbon capture system (1) and the thermal power generating unit (2); the high-temperature energy storage device (3) is used for acquiring and storing heat energy of reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam provided by the thermal power generating unit (2), heating condensation water from the thermal power generating unit (2) by utilizing the stored heat energy so as to generate first high-temperature steam and conveying the first high-temperature steam to the flue gas carbon capture system (1).

2. The flue gas carbon capture and steam supply system with improved peak shaving capability according to claim 1, wherein the high temperature energy storage device (3) comprises: the high-temperature molten salt heat storage tank (31), the low-temperature molten salt heat storage tank (32), the first heat exchange component (33) and the second heat exchange component (34);

the high-temperature molten salt heat storage tank (31), the first heat exchange assembly (33), the low-temperature molten salt heat storage tank (32) and the second heat exchange assembly (34) are connected through pipelines in sequence;

The high-temperature molten salt heat storage tank (31) stores liquid salt, the high-temperature molten salt heat storage tank (31) is provided with a high-temperature inlet and a high-temperature outlet, the high-temperature molten salt heat storage tank (31) acquires and stores heat energy of reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam of the thermal power generating unit (2) through the liquid salt, the liquid salt after acquiring the heat energy becomes high-temperature liquid salt, and the high-temperature liquid salt is output by the high-temperature molten salt heat storage tank (31);

The low-temperature molten salt heat storage tank (32) is provided with a low-temperature inlet and a low-temperature outlet, the low-temperature inlet of the low-temperature molten salt heat storage tank (32) is connected with the high-temperature outlet of the high-temperature molten salt heat storage tank (31) through a pipeline, the low-temperature outlet of the low-temperature molten salt heat storage tank (32) is connected with the high-temperature inlet of the high-temperature molten salt heat storage tank (31) through a pipeline, and the low-temperature molten salt heat storage tank (32) is used for storing and outputting high-temperature liquid salt after heat loss, wherein the high-temperature liquid salt after heat loss is low-temperature liquid salt;

The first heat exchange component (33) is arranged on a pipeline between a low-temperature inlet of the low-temperature molten salt heat storage tank (32) and a high-temperature outlet of the high-temperature molten salt heat storage tank (31) and is connected with the flue gas carbon capture system (1), and the first heat exchange component (33) performs heat exchange with condensation water from the thermal power generating unit (2) by utilizing high-temperature liquid salt output by the high-temperature molten salt heat storage tank (31) to generate first high-temperature steam and conveys the first high-temperature steam to the flue gas carbon capture system (1);

The second heat exchange assembly (34) is arranged on a pipeline between a low-temperature outlet of the low-temperature molten salt heat storage tank (32) and a high-temperature inlet of the high-temperature molten salt heat storage tank (31) and is connected with the thermal power generating unit, the second heat exchange assembly (34) utilizes low-temperature liquid salt output by the low-temperature molten salt heat storage tank (32) to exchange heat with reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam from the thermal power generating unit, and the low-temperature liquid salt absorbs heat energy of the reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam to become high-temperature liquid salt and stores the high-temperature liquid salt into the high-temperature molten salt heat storage tank (31).

3. The enhanced peaking capability flue gas carbon capture and steam supply system of claim 2, wherein the first heat exchange assembly (33) comprises: a first heat exchange conduit (334) and a first evaporator (332) and a first preheater (333) arranged in sequence on the conduit between the high temperature outlet and the low temperature inlet;

One end of the first heat exchange pipeline (334) is communicated with the flue gas carbon capture system (1), and the other end of the first heat exchange pipeline is communicated with a pipeline between the first evaporator (332) and the high-temperature molten salt heat storage tank (31);

The high-temperature liquid salt output by the high-temperature molten salt heat storage tank (31) sequentially flows through the first evaporator (332) and the first preheater (333), the condensed water sequentially flows through the first preheater (333) and the first evaporator (332), the high-temperature liquid salt and the condensed water are subjected to heat exchange respectively in the first preheater (333) and the first evaporator (332), the high-temperature liquid salt after heat loss becomes low-temperature liquid salt and enters the low-temperature molten salt heat storage tank (32), and the condensed water becomes first high-temperature steam after heat loss is conveyed to the flue gas carbon capture system (1) through the first heat exchange pipeline (334).

4. A flue gas carbon capture steam supply system with improved peak shaving capability according to claim 3, wherein the first heat exchange assembly (33) further comprises: the first superheater (331) is arranged on a pipeline between the high-temperature outlet and the first evaporator (332), and the first superheater (331) performs heat exchange with the first high-temperature steam by utilizing the high-temperature liquid salt output by the high-temperature molten salt heat storage tank (31) so as to generate and output superheated steam.

5. The enhanced peaking capability flue gas carbon capture and steam supply system of claim 4, wherein the second heat exchange assembly (34) comprises: a second supercooling heat exchanger (341), a second condensing heat exchanger (342), and a second superheating heat exchanger (343) which are sequentially disposed on a pipe between the low temperature outlet and the high temperature inlet;

The low-temperature liquid salt output by the low-temperature molten salt heat storage tank (32) sequentially flows through the second supercooling heat exchanger (341), the second condensation heat exchanger (342) and the second superheating heat exchanger (343), the reheat hot-section steam and/or reheat cold-section steam from the thermal power unit (2) sequentially flows through the second superheating heat exchanger (343), the second condensation heat exchanger (342) and the second supercooling heat exchanger (341), the low-temperature liquid salt and the reheat hot-section steam and/or reheat cold-section steam from the thermal power unit (2) are subjected to heat exchange in the second superheating heat exchanger (343), the second condensation heat exchanger (342) and the second supercooling heat exchanger (341), the low-temperature liquid salt after heat is obtained is conveyed to the high-temperature molten salt heat storage tank (31), and the reheat hot-section steam and/or reheat cold-section steam after heat loss is conveyed back to the thermal power unit (2).

6. The enhanced peak shaving capability flue gas carbon capture and steam supply system of claim 5, further comprising: and one end of the second steam supply bypass pipeline (4) is communicated with the flue gas carbon capture system (1), the other end of the second steam supply bypass pipeline (4) is communicated with a pipeline between the second condensation heat exchanger (342) and the second superheating heat exchanger (343), and the second steam supply bypass pipeline (4) is used for conveying reheat hot section steam and/or reheat cold section steam losing heat in the second superheating heat exchanger (343) to the flue gas carbon capture system (1).

7. The enhanced peak shaving capability flue gas carbon capture and steam supply system of claim 2, further comprising: the third overheat heat exchanger (5) is communicated with the low-temperature molten salt heat storage tank (32) and the second heat exchange assembly (34) through a pipeline, the thermal power unit (2) and the flue gas carbon capture system (1), the third overheat heat exchanger (5) utilizes medium-pressure exhaust steam provided by the thermal power unit (2) to perform heat exchange with low-temperature liquid salt output by the low-temperature molten salt heat storage tank (32) so as to preheat the low-temperature liquid salt, and the medium-pressure exhaust steam after heat loss is conveyed to the flue gas carbon capture system (1).

8. The enhanced peaking capability flue gas carbon capture and steam supply system of claim 6, wherein the flue gas carbon capture auxiliary system further comprises: the external steam supply header (6) is communicated with the thermal power unit (2), the first superheater (331) and the second steam supply bypass pipeline (4) through pipelines, the external steam supply header (6) is used for recycling reheat cold section steam conveyed by the thermal power unit (2), superheated steam and reheat hot section steam and/or reheat cold section steam which flow through the second steam supply bypass pipeline (4) and lose heat in the second superheating heat exchanger (343) to become mixed steam, and the mixed steam is used as a heat source to supply heat to the outside.

9. A flue gas carbon trapping and steam supplying method for improving peak regulation capability is realized based on the flue gas carbon trapping and steam supplying system for improving peak regulation capability according to any one of claims 1-8,

The flue gas carbon capturing and steam supplying method comprises the following steps:

the method comprises the steps of obtaining and storing heat energy of reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam conveyed by a thermal power generating unit (2) through a high-temperature energy storage device (3), and heating condensation water from the thermal power generating unit (2) by utilizing the stored heat energy to generate first high-temperature steam and conveying the first high-temperature steam to a flue gas carbon capture system (1).

10. The method for capturing and supplying the flue gas carbon with the peak shaving capacity improved according to claim 9, wherein the high-temperature energy storage device (3) acquires and stores heat energy of reheat hot section steam, reheat cold section steam and/or medium-pressure exhaust steam of the thermal power generating unit (2) through liquid salt stored in a high-temperature molten salt heat storage tank (31).