Thermodynamic system based on energy mass flow space-time matching

Abstract

The invention discloses a thermodynamic system based on energy mass flow space-time matching, which comprises a boiler system, a steam turbine system, a feed water heating system, a flexible peak regulation system, a condensation system and a temperature and pressure reduction system, and the thermodynamic system is constructed by introducing the flexible peak regulation system on a traditional subcritical unit. The boiler system is connected with the steam turbine system, the steam turbine system is connected with the feed water heating system and the condensation system, the feed water heating system is connected with the boiler system, the condensation system is connected with the feed water heating system, the flexible peak regulation system comprises a flexible powder storage system and a steam heat accumulator group, and the flexible powder storage system is connected with the boiler system. The steam heat accumulator group is connected with the water heating system and the temperature and pressure reducing system; the subcritical unit achieves energy mass flow space-time matching through the coupling flexible powder storage and supply system and the steam heat accumulator set. By constructing the thermodynamic system, deep peak regulation of the unit can be achieved, the cost of flexible transformation can be greatly reduced, and the operation benefits of the unit are increased.

Description

Technical Field

[0001] The present invention relates to the field of thermal power engineering, and in particular to a thermal system based on time-space matching of energy and mass flows. Background Art

[0002] In recent years, under the dual carbon background, the installed capacity and power generation of renewable energy represented by wind power and solar energy have grown rapidly. However, the power generation process of a high proportion of renewable energy is intermittent and uncertain, which will bring great challenges to the stable operation of the power grid after being connected to the grid. The rapid consumption of large-scale new energy has put forward higher requirements for the flexible operation of thermal power units. Deep peak regulation of coal-fired power generation is the "ballast stone" of power grid security.

[0003] Subcritical units currently represent the least efficient and most coal-intensive type of coal-fired power generation. However, their sheer volume makes them a crucial barrier to carbon emission reduction in the coal-fired power industry. Currently implemented flexible and efficient retrofit technologies for subcritical units face significant challenges, as they struggle to meet the modern energy system's demand for rapid, wide-load peaking (18% to 100% peaking, with a 5% / min load ramp) due to insufficient spatial and temporal alignment of energy and mass flows.

[0004] Therefore, based on the operating characteristics of coal-fired units, in order to better meet the requirements of energy conservation and efficiency improvement of coal-fired power plants and improve the survivability of subcritical units, a thermal system is needed for existing subcritical units to achieve spatiotemporal matching of energy and mass flows to improve the flexibility of the units.

[0005] Existing flexible operation plans for coal-fired units mainly focus on the transformation of the boiler-side combustion system and the steam turbine-side components. There are problems with the transformation plan being complex and the transformation cost being high, which will make the transformation of coal-fired units difficult and the overall economic efficiency poor. However, the transformation process of adding a flexible peak-shaving system to the coal-fired unit is relatively simple and the transformation cost is relatively low. Therefore, flexibility research on coal-fired units can be carried out based on this technology. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of time-space mismatch of energy and mass flows in the peak regulation process of traditional coal-fired units and to provide a thermal system based on time-space matching of energy and mass flows.

[0007] The object of the present invention is achieved through the following technical solutions: a thermal system based on time-space matching of energy and mass flows, comprising: a boiler system, a steam turbine system, a flexible peak-shaving system, a feedwater heating system, a condensing system, and a temperature and pressure reduction system;

[0008] The flexible peak-shaving system includes a flexible powder supply and storage system and a steam accumulator group;

[0009] The inlet of the boiler system is connected to the flexible pulverized coal supply and storage system and the feedwater heating system, and the outlet is connected to the steam turbine system. The boiler system burns the pulverized coal flowing in from the flexible pulverized coal supply and storage system, and generates superheated steam and reheated steam through the feedwater flowing in from the feedwater heating system, which are then output to the steam turbine system.

[0010] The inlet of the steam turbine system is connected to the boiler system, and the outlet is connected to the condensation system and the temperature and pressure reduction system. The superheated steam and reheated steam input are expanded to generate power. The steam flowing out of the steam turbine system is condensed and utilized by the condensation system, and then enters the feed water heating system for heating.

[0011] The inlet of the desuperheating and pressure reduction system is connected to the steam turbine system, and the outlet is connected to the steam accumulator group, which is used to reduce the steam pressure and temperature coming out of different sections of the steam turbine system to match the parameters required by the steam accumulator group;

[0012] The steam accumulator group includes a high-pressure steam accumulator and a low-pressure steam accumulator, the inlet of which is connected to the temperature reduction and pressure reduction system, and the outlet is connected to the feed water heating system to regulate the coal powder supply and steam latent heat storage.

[0013] Furthermore, the flexible pulverized coal supply and storage system monitors the load changes of the unit in real time, accurately adjusts the supply of pulverized coal, and realizes dynamic matching of pulverized coal and boiler heat demand; when the load increases, the pulverized coal supply is quickly increased by adjusting the speed of the pulverized coal mill or adjusting the working state of the pulverized coal storage and conveying device; when the load decreases, the pulverized coal supply is reduced to avoid excessive combustion.

[0014] Furthermore, the steam turbine system includes a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder. The superheated steam generated by the boiler system is transported to the high-pressure cylinder to expand and perform work, and then the steam is input into the boiler system for intermediate reheating, input into the intermediate-pressure cylinder and the low-pressure cylinder to continue to perform work, and then the gas is discharged to the condensation system and the temperature and pressure reduction system.

[0015] Furthermore, the temperature reduction and pressure reduction system includes a No. 1 temperature reduction and pressure reduction device and a No. 2 temperature reduction and pressure reduction device, which respectively meet the steam parameter safety range of the high-pressure steam accumulator and the low-pressure steam accumulator.

[0016] Furthermore, the steam accumulator group includes a high-pressure steam accumulator and a low-pressure steam accumulator. The heat storage steam source of the steam accumulator comes from the main steam and reheated steam of the unit. The heat release steam of the high-pressure steam accumulator is used to replace the high-pressure extraction steam of the feed water heating system, and the heat release steam of the low-pressure steam accumulator is used as an additional steam source for the low-pressure cylinder steam inlet.

[0017] Furthermore, the regulation strategy of the steam accumulator group is:

[0018] The high-pressure steam accumulator stores excess high-pressure steam produced by the unit when the load is low, and releases the stored steam when the load demand rises sharply to meet the demand for increased load.

[0019] The low-pressure steam accumulator acts on the low-pressure steam part of the unit and is suitable for slow but stable load regulation. When the unit load demand is low, the low-pressure steam accumulator stores low-pressure steam and gradually releases it when the load recovers, ensuring a stable steam supply.

[0020] Furthermore, the condensation system includes a condenser and a cooling tower. The low-temperature, low-pressure steam output by the steam turbine system enters the condenser for condensation and cooling into condensed water, which then enters the feed water heating system. The cold water used to condense the steam flows into the cooling tower for cooling for subsequent use.

[0021] Furthermore, the feedwater heating system includes a No. 1 high-pressure heater, a No. 2 high-pressure heater, a No. 3 high-pressure heater, a feedwater pump, a deaerator, a No. 5 low-pressure heater, a No. 6 low-pressure heater, a No. 7 low-pressure heater, a No. 8 low-pressure heater and a condensate pump.

[0022] The condensate output from the condensation system is sent by the condensate pump to the No. 8 low-pressure heater, No. 7 low-pressure heater, No. 6 low-pressure heater, and No. 5 low-pressure heater for heating in sequence. The feed water heated by the low-pressure heater enters the deaerator for deoxygenation, and collects the residual steam and drain water of the recovery unit. It is then sent by the deaerator to the feed water pump for pressure boosting, and is heated by the No. 3 high-pressure heater, No. 2 high-pressure heater, and No. 1 high-pressure heater respectively. The heated feed water is passed into the boiler system for further heating.

[0023] Furthermore, the No. 1 high-pressure heater, the No. 2 high-pressure heater and the No. 3 high-pressure heater are also provided with passages connected to the outlet of the high-pressure steam accumulator for heating the high-pressure steam outputted by the high-pressure steam accumulator.

[0024] Beneficial Effects of the Invention: The thermal system based on optimized energy-quality matching described in this invention improves the flexibility of traditional subcritical units by introducing a flexible peak-shaving system (a set of steam accumulators and a flexible pulverized coal supply and storage system). The thermal system of a traditional coal-fired unit generates superheated and reheated steam through a boiler system, which is output to the high-pressure, intermediate-pressure, and low-pressure cylinders of the turbine system for expansion and power generation. The steam, which has completed its work, is collected by a condenser and cooling tower and further heated by a feedwater heating system. The heated high-temperature water enters the boiler system for continued circulation. The flexible pulverized coal supply and storage system controls the pulverized coal input based on the required system load, solving the problem of slow pulverized coal supply from traditional boiler pulverized coal silos. High- and low-pressure steam accumulators are used as heat storage devices in typical subcritical units to increase their flexibility under variable load requirements. The steam accumulator group is a dual-accumulator configuration. The steam storage steam source for the steam accumulators comes from high-parameter steam, such as the unit's main steam and reheat steam. The released steam from the steam accumulators replaces the high-pressure steam extraction steam from the regenerative system and serves as an additional steam source for the low-pressure cylinder inlet. When the unit is de-loaded, high-pressure steam enters the steam accumulator, condenses, and releases latent heat of vaporization, which is stored in the water. When the unit is loaded, the pressure in the steam accumulator drops, and the high-temperature water inside flashes to form steam with different parameters, replacing the high-pressure steam extraction or replenishing air to the low-pressure cylinder. This thermal system modification is simple and less expensive than other modification technologies. It has a wide load adjustment range and high economic benefits. It not only achieves spatial and temporal matching of energy and mass flows, but also enables deep peak regulation of coal-fired units, laying the foundation for further flexibility improvements for subsequent coal-fired units. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a structural diagram of a thermal system based on time-space matching of energy and mass flows provided in an embodiment of the present application.

[0026] Figure 2 This is an output power diagram of a steam accumulator group at different times in a thermal system based on time-space matching of energy and mass flow provided in an embodiment of the present application.

[0027] Figure 3 This is a schematic diagram of the distribution of steam generation and power generation by a steam accumulator under different operating conditions of a thermal system based on spatiotemporal matching of energy and mass flows provided in an embodiment of the present application.

[0028] Among them, 1 is the boiler system, 2 is the steam turbine system, 3 is the flexible peak-shaving system, 4 is the feed water heating system, 5 is the condensation system, 6 is the temperature reduction and pressure reduction system, 7 is the flexible powder supply and storage system, 8 is the steam accumulator group, 9 is the high-pressure cylinder, 10 is the medium-pressure cylinder, 11 is the low-pressure cylinder, 12 is the No. 1 high-pressure heater, 13 is the No. 2 high-pressure heater, 14 is the No. 3 high-pressure heater, 15 is the feed water pump, 16 is the deaerator, 17 is the No. 5 low-pressure heater, 18 is the No. 6 low-pressure heater, 19 is the No. 7 low-pressure heater, 20 is the No. 8 low-pressure heater, 21 is the condensate pump, 22 is the condenser, 23 is the cooling tower, 24 is the high-pressure steam accumulator, 25 is the low-pressure steam accumulator, 26 and 27 are the temperature reduction and pressure reduction devices. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0030] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] Reference Attachment Figure 1 The thermal system based on the spatiotemporal matching of energy and mass flows described in the present invention mainly includes a boiler system 1, a steam turbine system 2, a flexible peak-shaving system 3, a feed water heating system 4, a condensing system 5, and a temperature and pressure reduction system 6. By introducing a flexible peak-shaving device, the traditional subcritical unit is flexibly transformed to achieve spatiotemporal matching of the energy and mass flows of the unit and improve the power generation flexibility of the unit.

[0032] The inlet of boiler system 1 is connected to flexible pulverized coal supply and storage system 7 and feedwater heating system 4. It receives pulverized coal from flexible pulverized coal supply and storage system 7. Flexible pulverized coal supply and storage system 7 controls the pulverized coal input based on the required system load, ensuring energy and mass flow matching between the boiler pulverized coal supply and steam work on the turbine side. The incoming pulverized coal then undergoes a vigorous combustion reaction under the influence of the primary and secondary air within the boiler, heating the boiler feedwater in the water-cooled wall and undergoing a phase change, generating superheated steam at a temperature of 538°C and a pressure of 16.67 MPa. The outlet of boiler system 1 is connected to turbine system 2.

[0033] The steam turbine system 2 is a single-shaft extraction condensing steam turbine, comprising a high-pressure cylinder 9, a medium-pressure cylinder 10 and a low-pressure cylinder 11. The superheated steam generated by the boiler system 1 is delivered to the high-pressure cylinder 9 of the steam turbine system 2 to expand and do work. The high-speed flowing steam drives the steam turbine blades to rotate, thereby driving the generator to rotate and generate electric energy. The boiler system 1 adopts a once-through intermediate reheat mode. The steam after work is returned to the boiler system 1 for reheating. The reheated steam with a temperature of 540°C and a pressure of 5.3 MPa is generated and delivered to the medium-pressure cylinder 10 of the steam turbine system 2 to expand and do work. After work, the steam enters the low-pressure cylinder 11 to continue to expand and do work. The exhaust steam has a temperature of 79°C and a pressure of 11 kPa. The steam flowing out of the steam turbine system 2 is condensed by the condensing system 5. After that, the condensed water enters the feedwater heating system 4 for heating.

[0034] The flexible peak regulation system 3 comprises a flexible coal powder supply and storage system 7 and a steam accumulator group 8.

[0035] In operation, the inlet of the flexible coal powder supply and storage system 7 is used for coal powder input. The outlet of the flexible coal powder supply and storage system 7 is connected with the boiler system 1, which is used for flexibly adjusting the amount of coal powder entering the boiler according to the required load, so as to accelerate the time of coal powder entering the boiler.

[0036] The flexible coal powder supply and storage system can accurately adjust the supply amount of coal powder by real-time monitoring of the load change of the unit, so as to realize dynamic matching of the coal powder and the thermal demand of the boiler. When the load increases, the system can quickly increase the supply amount of coal powder by adjusting the rotating speed of the coal powder mill or adjusting the working state of the coal powder storage and conveying device. When the load decreases, the supply of coal powder is reduced, so as to avoid excessive combustion. In order to accelerate the time of coal powder entering the boiler, the system can increase the conveying flow rate of the coal powder, so as to ensure that the coal powder is fully combusted in the shortest time, respond to the load change of the unit, improve the combustion efficiency and the stability of the system.

[0037] The steam accumulator group 8 comprises a high-pressure steam accumulator 24 and a low-pressure steam accumulator 25. The steam accumulator group 8 is connected with the steam turbine system 2 and the feedwater heating system 4. The steam accumulator group is designed as a double-accumulator configuration combining high-pressure and low-pressure accumulators. The heat storage steam source of the steam accumulator comes from the high-parameter steam such as the main steam and the reheat steam of the unit. The heat release steam of the steam accumulator is used to replace the high-pressure heater extraction steam of the regenerative system and as a new steam source for the low-pressure cylinder. The steam accumulator is used to adjust the supply and storage of coal powder and release the latent heat of steam according to the required load of the unit, so as to realize flexible power generation of the coal-fired unit.

[0038] The high-pressure steam accumulator is connected to the unit's high-pressure steam system. Its primary function is to quickly respond to load changes. Because high-pressure steam directly affects the unit's power output, the high-pressure steam accumulator stores excess high-pressure steam produced during periods of low load. When the load demand increases sharply, this stored steam is quickly released to meet the increased load demand. The high-pressure steam accumulator provides rapid and large-scale heat regulation, enabling the unit to achieve load adjustments in a relatively short period of time.

[0039] Low-pressure steam accumulators primarily serve the low-pressure steam portion of the unit and are suitable for slow but steady load regulation. When the unit's load demand is low, the LP steam accumulator stores low-pressure steam and gradually releases it when the load increases, ensuring a stable steam supply and avoiding the losses caused by frequent unit starts and stops. Low-pressure steam heat storage typically has a long response time, helping to smooth unit load changes, reduce fuel consumption, and improve the efficiency of coal-fired units.

[0040] The condensing system 5 includes a condenser 22 and a cooling tower 23. The inlet of the condensing system 5 is connected to the steam outlet of the low-pressure cylinder 11, and the outlet is connected to the feed water heating system 4. The temperature and pressure of the steam after the low-pressure cylinder 11 completes the work are greatly reduced, and it becomes low-temperature and low-pressure steam. It enters the condenser 22 for condensation and cooling into condensate, and then enters the feed water heating system 4. The cold water used to condense the steam flows into the cooling tower 23 for cooling for subsequent use.

[0041] The feedwater heating system 4 includes a No. 1 high-pressure heater 12, a No. 2 high-pressure heater 13, a No. 3 high-pressure heater 14, a feedwater pump 15, a deaerator 16, a No. 5 low-pressure heater 17, a No. 6 low-pressure heater 18, a No. 7 low-pressure heater 19, a No. 8 low-pressure heater 20, and a condensate pump 21. Condensate from the condenser 22 is sequentially delivered by the condensate pump 21 to the No. 8 low-pressure heater 20, No. 7 low-pressure heater 19, No. 6 low-pressure heater 18, and No. 5 low-pressure heater 17 of the feedwater heating system 4 for heating. To remove oxygen from the feedwater, the feedwater heated by the aforementioned low-pressure heaters enters the deaerator 16 for deoxygenation. This prevents corrosion of the equipment and its steam-water system piping, and collects the residual steam and drain water from the recovery unit. The deaerator 16 then delivers the condensate to the feedwater pump 15 for pressure boosting, where it is heated by the No. 3 high-pressure heater 14, the No. 2 high-pressure heater 13, and the No. 1 high-pressure heater 12, respectively. In order to increase the feed water temperature, the intermediate pressure cylinder 10 will discharge part of the high-temperature steam to the No. 3 high-pressure heater 14, and the high-pressure cylinder 9 will discharge part of the high-temperature steam to the No. 2 high-pressure heater 13 and the No. 1 high-pressure heater 12 respectively. Finally, the feed water temperature reaches 277°C, and the heated feed water is passed into the boiler system 1 for further heating.

[0042] The cooling and pressure reduction system 6 includes a No. 1 cooling and pressure reduction device 26 and a No. 2 cooling and pressure reduction device 27. The cooling and pressure reduction system 6 is used to reduce the pressure and temperature of the high-pressure cylinder 9. At this time, it is connected through a valve to meet the steam parameter safety range of the high-pressure steam accumulator 24 and the low-pressure steam accumulator 25 to ensure the safe operation of the steam accumulator group.

[0043] The specific implementation effect of the above method is demonstrated below with reference to examples.

[0044] Example

[0045] In this example, a 300MW subcritical unit produced by China Huadian Group was used as a research object to explore the effect of the steam accumulator group on improving the peak-shaving performance of the original unit.

[0046] The main parameters of the original 300MW unit are shown in Table 1:

[0047] Table 1 Main parameter values ​​of 300MW subcritical unit

[0048] Main steam flow 1130t / h Main steam pressure 16.67Mpa Main steam temperature 538℃ Resteam flow 940t / h Reheat steam temperature 540℃ Low pressure cylinder exhaust pressure 11 / 28kPa Feed water temperature 277℃ Superheater outlet steam flow (BMCR) 1164t / h Heat rate of the unit under THA condition 8317kJ / kW·h Plant power consumption rate 5.3％ Pipeline efficiency 99％ Design standard coal consumption of power generation unit 307g / kW·h Design standard coal consumption of unit power supply 324.2g / kW·h

[0049] The main parameters of the steam accumulator group in the unit are shown in Table 2:

[0050] Table 2 Main parameter values ​​of steam accumulator group

[0051]

[0052]

[0053] The steam accumulator group is designed as a dual accumulator configuration with high and low pressure. The steam source for the steam accumulator is the main steam, reheat steam and other high-parameter steam of the unit. The heat released by the steam accumulator is used to replace the high-pressure steam extraction of the heat recovery system and as an additional steam source for the low-pressure cylinder steam inlet. The system connection is as shown in the attached Figure 1 When the unit is de-loaded, the high-parameter steam of the unit enters the heat accumulator, condenses and releases the latent heat of vaporization which is stored in the water. When the unit is loaded, the pressure in the heat accumulator drops, and the high-temperature water inside forms steam of different parameters through flash evaporation, which replaces the extraction steam of the high-pressure heater or provides steam to the low-pressure cylinder to perform work.

[0054] The overall design concept of the steam accumulator group is to meet the main AGC instruction application scenarios and the variable load requirements of the steam turbine side, determine the continuous operation time of the unit with rapid load changes, and then determine the amount of steam required by the steam accumulator based on the incremental work of the steam turbine, and finally determine the basic design parameters of the steam accumulator.

[0055] After analyzing the AGC instruction scenarios, the steam capacity corresponding to 15% Pe in the steam accumulator design can meet the needs of most application scenarios. Figure 2The transient characteristics of steam accumulator steam supply and power generation in the thermal system of a typical 300MW subcritical unit coupled with a steam accumulator are demonstrated when the Pe is increased from 30% to 45% Pe: the unit completes the load increase operation in 3 minutes, and the steam supply of the steam accumulator gradually increases in the first 3 minutes. The steam production reaches a peak in the 3rd minute, corresponding to an electric power of 27MW; after that, the steam accumulator continues to supply steam to the outside, and the steam supply gradually decreases until the boiler steam production reaches a stable load level.

[0056] Table 3 Power changes of coal-fired units with steam accumulator groups

[0057]

[0058] There are two main ways to use the steam produced by the steam accumulator: one is to pass it into the high-pressure heater to heat the feed water, reducing / replacing the high-pressure cylinder extraction steam; the other is to pass it directly into the low-pressure cylinder to generate power. Under different operating loads of the unit, the steam distribution ratio of the steam accumulator varies, such as Figure 3 The figure shows these differences quantitatively. The steam accumulator's instantaneous maximum steam production capacity can reach 27MW, corresponding to a steam flow rate. At low unit load, the HPH extracts relatively little steam, and the resulting power generation cannot meet the unit's increased load requirements. Therefore, most of the steam produced by the steam accumulator must be allocated to the LPH for direct power generation. As the unit load increases, the demand for HPH steam increases, and more steam produced by the steam accumulator can be allocated to the HPH, gradually reducing the amount of steam allocated to the LPH.

[0059] The dynamic optimization distribution of steam produced by the steam accumulator can achieve dynamic matching of energy and mass flow in the transient process of the unit while meeting the variable load operation, thus reducing Loss, expand the energy-saving theory from steady-state conditions to transient processes, reduce transient energy consumption during rapid load changes, and achieve energy-saving operation of the thermal system of subcritical units.

[0060] According to the results obtained, it can be found that the flexibility of the coal-fired unit can be improved by introducing a steam heat accumulator group, which shows that the thermal system has a certain peak-shaving capability and can ensure the real-time peak-shaving demand of the power plant.

[0061] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0062] It should be understood that the above general description and the detailed description that follows are exemplary and explanatory only and do not limit the present application. The present application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope of the present application. The scope of the present application is limited only by the appended claims.

Claims

1. A thermal system based on time-space matching of energy and mass flow, characterized in that: include: Boiler system, steam turbine system, flexible peak-shaving system, feedwater heating system, condensing system and temperature and pressure reduction system; The flexible peak-shaving system includes a flexible powder supply and storage system and a steam accumulator group; The inlet of the boiler system is connected to the flexible pulverized coal supply and storage system and the feedwater heating system, and the outlet is connected to the steam turbine system. The boiler system burns the pulverized coal flowing in from the flexible pulverized coal supply and storage system, and generates superheated steam and reheated steam through the feedwater flowing in from the feedwater heating system, which are then output to the steam turbine system. The inlet of the steam turbine system is connected to the boiler system, and the outlet is connected to the condensation system and the temperature and pressure reduction system. The superheated steam and reheated steam input are expanded to generate power. The steam flowing out of the steam turbine system is condensed and utilized by the condensation system, and then enters the feed water heating system for heating. The inlet of the desuperheating and pressure reduction system is connected to the steam turbine system, and the outlet is connected to the steam accumulator group, which is used to reduce the steam pressure and temperature coming out of different sections of the steam turbine system to match the parameters required by the steam accumulator group; The steam accumulator group includes a high-pressure steam accumulator and a low-pressure steam accumulator, the inlet of which is connected to the temperature reduction and pressure reduction system, and the outlet is connected to the feed water heating system to regulate the coal powder supply and steam latent heat storage.

2. A thermal system based on time-space matching of energy and mass flow according to claim 1, characterized in that: The flexible pulverized coal supply and storage system monitors unit load changes in real time and accurately adjusts the pulverized coal supply to achieve dynamic matching of pulverized coal and boiler heat demand. When the load increases, the pulverized coal supply is quickly increased by adjusting the speed of the pulverized coal mill or the working state of the pulverized coal storage and conveying device. When the load decreases, the pulverized coal supply is reduced to avoid over-combustion.

3. A thermal system based on time-space matching of energy and mass flow according to claim 1, characterized in that: The steam turbine system includes a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder. The superheated steam generated by the boiler system is transported to the high-pressure cylinder to expand and perform work. The steam is then input into the boiler system for intermediate reheating and input into the intermediate-pressure cylinder and the low-pressure cylinder to continue performing work. The gas is then discharged into the condensation system and the temperature and pressure reduction system.

4. A thermal system based on time-space matching of energy and mass flow according to claim 1, characterized in that: The temperature reduction and pressure reduction system includes a No. 1 temperature reduction and pressure reduction device and a No. 2 temperature reduction and pressure reduction device, which respectively meet the steam parameter safety range of the high-pressure steam accumulator and the low-pressure steam accumulator.

5. The thermal system based on time-space matching of energy and mass flow according to claim 3, characterized in that: The steam accumulator group includes a high-pressure steam accumulator and a low-pressure steam accumulator. The heat storage steam source of the steam accumulator comes from the main steam and reheated steam of the unit. The heat release steam of the high-pressure steam accumulator is used to replace the high-pressure extraction steam of the feed water heating system, and the heat release steam of the low-pressure steam accumulator is used as an additional steam source for the low-pressure cylinder steam inlet.

6. A thermal system based on time-space matching of energy and mass flow according to claim 5, characterized in that: The regulation strategy of the steam accumulator group is: The high-pressure steam accumulator stores excess high-pressure steam produced by the unit when the load is low, and releases the stored steam when the load demand rises sharply to meet the demand for increased load. The low-pressure steam accumulator acts on the low-pressure steam part of the unit and is suitable for slow but stable load regulation. When the unit load demand is low, the low-pressure steam accumulator stores low-pressure steam and gradually releases it when the load recovers, ensuring a stable steam supply.

7. The thermal system based on time-space matching of energy and mass flow according to claim 1, characterized in that: The condensing system includes a condenser and a cooling tower. The low-temperature, low-pressure steam output by the steam turbine system enters the condenser for condensation and cooling into condensed water, which then enters the feed water heating system. The cold water used to condense the steam flows into the cooling tower for cooling and subsequent use.

8. The thermal system based on time-space matching of energy and mass flow according to claim 1, characterized in that: The feedwater heating system includes a No. 1 high-pressure heater, a No. 2 high-pressure heater, a No. 3 high-pressure heater, a feedwater pump, a deaerator, a No. 5 low-pressure heater, a No. 6 low-pressure heater, a No. 7 low-pressure heater, a No. 8 low-pressure heater and a condensate pump. The condensate output from the condensation system is sent by the condensate pump to the No. 8 low-pressure heater, No. 7 low-pressure heater, No. 6 low-pressure heater, and No. 5 low-pressure heater for heating in sequence. The feed water heated by the low-pressure heater enters the deaerator for deoxygenation, and collects the residual steam and drain water of the recovery unit. It is then sent by the deaerator to the feed water pump for pressure boosting, and is heated by the No. 3 high-pressure heater, No. 2 high-pressure heater, and No. 1 high-pressure heater respectively. The heated feed water is passed into the boiler system for further heating.

9. A thermal system based on time-space matching of energy and mass flow according to claim 8, characterized in that: The No. 1 high-pressure heater, the No. 2 high-pressure heater and the No. 3 high-pressure heater also have passages connected to the outlet of the high-pressure steam accumulator for heating the high-pressure steam output by the high-pressure steam accumulator.

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