Adjacent machine steam heating power generation system and power system

Abstract

The invention discloses an adjacent machine steam heating power generation system and an electric power system, and belongs to the technical field of unit energy saving and quick start and stop, new energy consumption and deep peak shaving of thermal power generating units, the adjacent machine steam heating power generation system comprises a first unit, a second unit, a first coupling pipeline and a second coupling pipeline, and the first unit comprises a first steam path and a first water return path; the second unit comprises a second steam path and a second water return path; an inlet and an outlet of the first coupling pipeline are respectively connected with the first branch port and the first preheating position; an inlet and an outlet of the second coupling pipeline are respectively connected with the second branch port and the second preheating position; the first branch opening is located upstream of the second branch opening, and the first preheating position is located upstream of the second preheating position. Before ignition, the first boiler is preheated to the temperature close to the temperature needed by hot-state flushing through steam of the second boiler, the starting time of the first boiler is effectively shortened, the first boiler can be put into operation more quickly, and therefore the starting and stopping efficiency of a power plant is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unit energy saving and rapid start and stop, new energy consumption, and deep peak regulation of thermal power units, and in particular to a steam heating power generation system and a power system for an adjacent machine, or a secondary adjacent machine boiler steam heating system for a deep peak regulation shift start and stop unit combined with new energy consumption. Background Art

[0002] The inherent characteristics of renewable energy generation have brought unprecedented challenges to the stable operation of the power system. Wind power generation, as an important part of renewable energy generation, is easily affected by natural wind conditions. In a complex and changeable wind environment, the power of wind power generation may fluctuate by more than 50% in a short period of time. This high degree of uncertainty makes it extremely difficult to accurately predict and effectively control wind power generation.

[0003] Similarly, solar power generation faces similar challenges. Its power generation efficiency is strictly limited by light conditions. The alternation of day and night and the change of weather will cause solar power generation to show significant intermittent characteristics. In rainy weather, the power of solar power generation may drop to less than 10% of that on sunny days. Such large power fluctuations pose a severe test to the frequency stability, voltage control and supply and demand balance of the power system, which can easily cause power grid fluctuations, affect the reliability and stability of power supply, and thus have an adverse impact on the quality of electricity used in production and life.

[0004] In this context, traditional thermal power generating units, as an important means of regulating the power system, lack an effective coordination mechanism between their inherent operating mode and the real-time output of renewable energy power generation. When renewable energy power generation increases significantly, thermal power generating units fail to adjust their loads in a timely and flexible manner, resulting in serious energy waste. In some areas, excess thermal power generation even accounts for 10% to 15% of total power generation. When renewable energy output drops sharply, thermal power generating units find it difficult to quickly increase power to fill the power gap. Emergency startup to full load takes several hours, which is far from meeting the requirements of rapid changes in power demand.

[0005] The existing adjacent machine heating technology has obvious shortcomings in improving the start-up and shutdown efficiency of thermal power generating units, and cannot effectively cope with the challenges brought by the volatility of renewable energy power generation.

[0006] Therefore, how to improve the start-up and shutdown efficiency of thermal power generating units and increase the consumption ratio of new energy has become a technical problem that needs to be solved urgently. Summary of the invention

[0007] The object of the present invention is to provide a neighboring unit steam heating power generation system and a power system to solve the problems existing in the above-mentioned prior art. The second steam path of the second unit is used to heat the first return water path of the first unit, and two-stage heating is formed. The first boiler has been preheated to a temperature close to that required for hot flushing by the steam of the second boiler before ignition, effectively shortening the start-up time of the first boiler and enabling the first boiler to be put into operation faster, thereby improving the start-stop efficiency of the power plant.

[0008] To achieve the above object, the present invention provides the following solutions: The present invention provides a neighboring unit steam heating power generation system, including a first unit, a second unit, a first coupling pipeline, and a second coupling pipeline. The first unit includes a first steam path and a first return water path. The inlet of the first steam path is connected to the outlet of the first boiler, the outlet of the first steam path is connected to the inlet of the first condenser, the inlet of the first return water path is connected to the outlet of the first condenser, and the outlet of the first return water path is connected to the inlet of the first boiler. The second unit includes a second steam path and a second return water path. The inlet of the second steam path is connected to the outlet of the second boiler, the outlet of the second steam path is connected to the inlet of the second condenser, the inlet of the second return water path is connected to the outlet of the second condenser, and the outlet of the second return water path is connected to the inlet of the second boiler. The inlet of the first coupling pipeline is connected to the first branch port of the second steam path, and the outlet of the first coupling pipeline is connected to the first preheating position of the first return water path. The inlet of the second coupling pipeline is connected to the second branch port of the second steam path, and the outlet of the second coupling pipeline is connected to the second preheating position of the second return water path. The first branch port is located upstream of the second branch port, and the first preheating position is located upstream of the second preheating position.

[0009] In an embodiment, the second steam path includes a second steam turbine high-pressure cylinder, a second steam turbine intermediate-pressure cylinder, and a second steam turbine low-pressure cylinder arranged in sequence. The first branch port is connected to the outlet of the second boiler, and the second branch port is connected to the outlet of the second steam turbine high-pressure cylinder.

[0010] In an embodiment, the second boiler is provided with a second reheater. The outlet of the second steam turbine high-pressure cylinder is connected to the inlet of the second reheater, the outlet of the second reheater is connected to the inlet of the second steam turbine intermediate-pressure cylinder, the outlet of the second steam turbine intermediate-pressure cylinder is connected to the inlet of the second steam turbine low-pressure cylinder, and the outlet of the second steam turbine low-pressure cylinder is connected to the inlet of the second condenser.

[0011] In one embodiment, the first water return path includes a first condensate pump, a first low-pressure heater, a first deaerator, a first feed water pump, and a first high-pressure heater arranged in sequence. The first preheating position is the first deaerator, and the second preheating position is the first high-pressure heater.

[0012] In one embodiment, the drain water of the first high-pressure heater flows by gravity to the first deaerator, and the drain water of the first low-pressure heater flows by gravity to the first condenser.

[0013] In one embodiment, the first steam path includes a first high-pressure cylinder of a steam turbine, a first intermediate-pressure cylinder of the steam turbine, and a first low-pressure cylinder of the steam turbine arranged in sequence; the first boiler is provided with a first reheater. The outlet of the first high-pressure cylinder of the steam turbine is connected to the inlet of the first reheater, the outlet of the first reheater is connected to the inlet of the first intermediate-pressure cylinder of the steam turbine, the outlet of the first intermediate-pressure cylinder of the steam turbine is connected to the inlet of the first low-pressure cylinder of the steam turbine, and the outlet of the first low-pressure cylinder of the steam turbine is connected to the inlet of the first condenser.

[0014] In one embodiment, the inlet of the first deaerator is respectively connected to the outlet of the first low-pressure heater, the extraction steam outlet of the first intermediate-pressure cylinder of the steam turbine, and the outlet of the second boiler, and the outlet of the first deaerator is connected to the first high-pressure heater.

[0015] In one embodiment, the inlet of the first high-pressure heater is respectively connected to the outlet of the first deaerator, the extraction steam outlet of the first high-pressure cylinder of the steam turbine, and the outlet of the second high-pressure cylinder of the steam turbine, and the outlet of the first high-pressure heater is connected to the inlet of the first boiler.

[0016] In one embodiment, the second water return path includes a second condensate pump, a second low-pressure heater, a second deaerator, a second feed water pump, and a second high-pressure heater arranged in sequence. The drain water of the second high-pressure heater flows by gravity to the second deaerator, and the drain water of the second low-pressure heater flows by gravity to the second condenser.

[0017] The present invention provides a power system, including a power generation system and a control system. The power generation system includes an adjacent unit steam heating power generation system and a new energy power generation system as described above; the control system includes a central control system, a power plant real-time monitoring system, and a new energy access and monitoring system. The adjacent unit steam heating power generation system delivers electricity to the power grid through the power plant real-time monitoring system, the new energy power generation system delivers electricity to the power grid through the new energy access and monitoring system, the power grid delivers electricity to electricity users through the central control system, and the central control system is connected to the power plant real-time monitoring system and the new energy access and monitoring system through negative feedback regulation.

[0018] The present invention has achieved the following technical effects compared with the prior art: The present invention uses the second steam path of the second unit to heat the first return water path of the first unit and forms two-stage heating. On the one hand, it can use the auxiliary steam of the adjacent unit's boiler (the second boiler) for preheating, reduce the heat input required by the local boiler (the first boiler) during the start-up phase, reduce the consumption of fuel oil and coal, and at the same time reduce the power consumption of the main auxiliary equipment, further reducing the overall cost of starting the first boiler, while improving the energy efficiency level and fast start-stop performance of the first unit; on the other hand, it can make more full use of the heat of the adjacent unit's boiler and improve the overall efficiency of the system. Thus, the first boiler has been preheated to a temperature close to that required for hot flushing by the steam of the second boiler before ignition, effectively shortening the start-up time of the first boiler, enabling the first boiler to be put into operation faster, greatly reducing the fuel oil consumption in the initial stage of ignition, directly reducing the fuel cost, and thus improving the start-stop efficiency of the power plant.

[0019] Other technical solutions included in the present invention can also achieve the following technical effects: On the basis of improving the start-stop efficiency of thermal power generating units, the power system of the present invention accurately matches the peak of new energy power generation with the shutdown time of coal-fired generating units, assists in adjusting the thermal power load during the peak of new energy power generation, taps potential to help new energy grid connection and consumption, optimizes the energy efficiency of the power system, significantly improves the new energy consumption ratio, promotes green and low-carbon power supply, optimizes the energy structure and reduces carbon emissions; at the same time, adopting a shift start-stop strategy optimizes the operation of coal-fired generating units, avoids the energy consumption and wear of long-term continuous operation, extends the service life of the units and reduces the operation cost.

[0020] In the power system, to meet the demand for new energy consumption, the present invention adopts a relatively frequent start-stop mode for thermal power generating units. By adopting the adjacent unit steam heating power generation system of the present invention, through reducing fuel consumption, the emissions of harmful gases and particulate matter generated during the boiler start-up process are reduced, which helps to improve air quality and reduce environmental pollution, meeting the environmental protection concept of sustainable development.

[0021] The present invention flexibly adjusts the start and stop of the first unit, enabling thermal power to quickly respond to new energy fluctuations, while increasing the peak shaving depth to ensure the stability and reliability of power supply, enhancing the peak shaving capacity of the power system, and ensuring the stable operation of power supply.

[0022] The present invention can achieve cascaded utilization of heat, recover waste heat to reduce costs, reasonably utilize the steam of the adjacent unit's boiler to reduce the start-up energy consumption of the local boiler, improve the energy efficiency and start-stop performance of the unit, and can also reduce thermal stress and extend the service life of equipment, contributing to the sustainable development of the power industry and having high application and promotion value.

[0023] By precisely controlling the feed water temperature, the present invention avoids the problem of thermal shock on the boiler heating surface caused by sudden changes in water temperature, reduces the risk of equipment damage caused by excessive thermal stress, reduces thermal shock and temperature fluctuations, extends the service life of the boiler and its auxiliary equipment, reduces long-term operation and maintenance costs, shortens the boiler startup time, enables the unit to be put into operation faster, and thus improves the production efficiency of the power plant. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the power system in the embodiment of the present invention; Figure 2 Daily load curve in the embodiment of the present invention; Figure 3 Power generation curve in the embodiment of the present invention; Figure 4 Daily load curve after new energy consumption in the embodiment of the present invention; Wherein, 1. First boiler; 2. High-pressure cylinder of the first steam turbine; 3. Intermediate-pressure cylinder of the first steam turbine; 4. Low-pressure cylinder of the first steam turbine; 5. First generator; 6. First condenser; 7. First condensate pump; 8. First low-pressure heater; 9. First deaerator; 10. First feed water pump; 11. First high-pressure heater; 12. Second boiler; 13. High-pressure cylinder of the second steam turbine; 14. Intermediate-pressure cylinder of the second steam turbine; 15. Low-pressure cylinder of the second steam turbine; 16. Second generator; 17. Second condenser; 18. Second condensate pump; 19. Second low-pressure heater; 20. Second deaerator; 21. Second feed water pump; 22. Second high-pressure heater; 23. Wind power generation system; 24. Photovoltaic power generation system; 25. Power grid; 26. Electricity users; 27. Power plant real-time monitoring system; 28. New energy access and monitoring system; 29. Central control system; 100. First coupling pipeline; 200. Second coupling pipeline. Detailed Embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] The purpose of the present invention is to provide an adjacent unit steam heating power generation system and a power system to solve the problems existing in the prior art. The second steam path of the second unit is used to heat the first return water path of the first unit, and two-stage heating is formed. The first boiler has been preheated to a temperature close to that required for hot state flushing by the steam of the second boiler before ignition, effectively shortening the start-up time of the first boiler and enabling the first boiler to be put into operation faster, thereby improving the start-stop efficiency of the power plant.

[0028] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] As Figure 1 shown, the present invention provides an adjacent unit steam heating power generation system, including a first unit, a second unit, a first coupling pipeline 100, and a second coupling pipeline 200. The first unit and the second unit are respectively thermal power generation units, such as air-cooled coal-fired power generation units, and are both equipped with key equipment such as coal-fired boilers and steam turbines. The first coupling pipeline 100 and the second coupling pipeline 200 adopt high-temperature and high-pressure resistant pipelines, and the first unit and the second unit are connected into an adjacent unit heating network through the first coupling pipeline 100 and the second coupling pipeline 200.

[0030] The first unit includes a first steam path and a first return water path. Among them, the first steam path is mainly the operation and work path of superheated steam, and the first return water path is mainly the reflux and reheating path of condensate. The inlet of the first steam path is connected to the outlet of the first boiler 1, and the outlet of the first steam path is connected to the inlet of the first condenser 6. The superheated steam generated by the first boiler 1 is condensed into condensate in the first condenser 6 after doing work. The inlet of the first return water path is connected to the outlet of the first condenser 6, and the outlet of the first return water path is connected to the inlet of the first boiler 1. The condensate of the first condenser 6 enters the first boiler 1 after being preheated.

[0031] The second unit includes a second steam path and a second water return path. Among them, the second steam path is mainly the operating and working path of superheated steam, and the second water return path is mainly the reflux and reheating path of condensate. The inlet of the second steam path is connected to the outlet of the second boiler 12, and the outlet of the second steam path is connected to the inlet of the second condenser 17. The superheated steam generated by the second boiler 12 is condensed into condensate in the second condenser 17 after doing work. The inlet of the second water return path is connected to the outlet of the second condenser 17, and the outlet of the second water return path is connected to the inlet of the second boiler 12. The condensate of the second condenser 17 enters the second boiler 12 after being preheated.

[0032] The inlet of the first coupling pipeline 100 is connected to the first branch port of the second steam path, and the outlet of the first coupling pipeline 100 is connected to the first preheating position of the first water return path. The inlet of the second coupling pipeline 200 is connected to the second branch port of the second steam path, and the outlet of the second coupling pipeline 200 is connected to the second preheating position of the second water return path. Thus, the first water return path of the first unit can be preheated by the steam of the second steam path of the second unit, and two-stage preheating is formed. The first branch port is located upstream of the second branch port, and the first preheating position is located upstream of the second preheating position. That is to say, during the two-stage preheating process, high-temperature steam is used for the first-stage preheating of low-temperature water, and then the steam after temperature reduction is used for the second-stage preheating of the water after temperature rise. In this way, a gradient preheating method is formed to improve the heating efficiency of adjacent unit steam preheating.

[0033] It should be noted that: for the setting modes of the first unit and the second unit, it can be one-to-one, many-to-one or one-to-many, that is, the first unit can be correspondingly connected to one or more groups of second units, and multiple groups of first units can also be correspondingly connected to one group of second units to form a variety of different start-stop strategies and achieve the reasonable and effective utilization of steam. For different mode settings, the adjustment can be made by adjusting the setting quantity of the first coupling pipeline 100 and the second coupling pipeline 200.

[0034] The present invention heats the first return water path of the first unit by using the second steam path of the second unit to form two-stage heating. On the one hand, it can use the auxiliary steam of the adjacent boiler (the second boiler 12) for preheating, reduce the heat input required by the local boiler (the first boiler 1) during the start-up phase, reduce the consumption of fuel oil and coal, and at the same time reduce the power consumption of the main auxiliary equipment, further reducing the overall cost of starting the first boiler 1, while improving the energy efficiency level and fast start-stop performance of the first unit; on the other hand, it can make more full use of the heat of the adjacent boiler and improve the overall efficiency of the system. Thus, the first boiler 1 has been preheated to a temperature close to that required for hot flushing by the steam of the second boiler 12 before ignition, effectively shortening the start-up time of the first boiler 1, enabling the first boiler 1 to be put into operation faster, greatly reducing the fuel oil consumption in the initial stage of ignition, directly reducing the fuel cost, and thus improving the start-stop efficiency of the power plant.

[0035] The adjacent unit steam heating power generation system of the present invention, as a thermal power unit, can be organically coupled with diversified new energy power generation systems such as a wind power generation system 23 and a photovoltaic power generation system 24, and is jointly connected to the power grid 25 for power supply through a dynamic monitoring system (a power plant real-time monitoring system 27 and a new energy access and monitoring system 28). At night, the new energy output is low, and the two units operate simultaneously to ensure the basic power consumption of the electricity users 26; when the new energy resources are rich during the day, one unit is shut down to expand the new energy consumption and enhance the peak shaving depth of the thermal power unit. At this time, the peak value of new energy power generation is about 8 hours. The shut-down shift unit is in a hot start state during this period and can be quickly started relying on the adjacent unit steam heating power generation system.

[0036] In an embodiment, the second steam path includes a second steam turbine high-pressure cylinder 13, a second steam turbine intermediate-pressure cylinder 14, and a second steam turbine low-pressure cylinder 15 arranged in sequence. The three are coaxially connected and drive the second generator 16 to generate electricity. The first branch port is connected to the outlet of the second boiler 12, and the second branch port is connected to the outlet of the second steam turbine high-pressure cylinder 13. That is, the steam at the first branch port is the superheated steam generated by heating in the second boiler 12, and the steam at the second branch port is the steam after doing work in the second steam turbine high-pressure cylinder 13. The steam at the first branch port and the second branch port have different temperatures and respectively heat different positions of the first return water path to achieve a gradient heating method.

[0037] In an embodiment, the second boiler 12 is provided with a second reheater. The outlet of the high-pressure cylinder 13 of the second steam turbine is connected to the inlet of the second reheater, the outlet of the second reheater is connected to the inlet of the intermediate-pressure cylinder 14 of the second steam turbine, the outlet of the intermediate-pressure cylinder 14 of the second steam turbine is connected to the inlet of the low-pressure cylinder 15 of the second steam turbine, and the outlet of the low-pressure cylinder 15 of the second steam turbine is connected to the inlet of the second condenser 17. In the second unit, the superheated steam generated by the second boiler 12 first enters the high-pressure cylinder 13 of the second steam turbine, then enters the second reheater for heating, and then sequentially enters the intermediate-pressure cylinder 14 and the low-pressure cylinder 15 of the second steam turbine, and finally enters the second condenser 17 for condensation, fully utilizing the energy of the steam to ensure the power generation efficiency of the second unit.

[0038] In an embodiment, the first water return path includes a first condensate pump 7, a first low-pressure heater 8, a first deaerator 9, a first feed water pump 10, and a first high-pressure heater 11 arranged in sequence. In the first unit, the condensate water of the first condenser 6 is pumped by the first condensate pump 7, first enters the first low-pressure heater 8 for preheating, then enters the first deaerator 9 for deaeration and other treatments, and then enters the first high-pressure heater 11 for further preheating under the action of the first feed water pump 10, and finally enters the first boiler 1. The first preheating position is the first deaerator 9, that is, the steam in the second steam path performs primary heating on the return water in the first deaerator 9, realizing multiple possible heat transfer paths, enabling the system to flexibly adjust the heat distribution according to actual needs, and improving the adaptability and flexibility of the system; the second preheating position is the first high-pressure heater 11, that is, the steam in the second steam path performs secondary heating on the return water in the first high-pressure heater 11, realizing more efficient utilization of the heat of the adjacent unit boiler, while improving the stability and reliability of the system, constituting an efficient secondary adjacent unit steam heating power generation system.

[0039] The outlet of the second boiler 12 is connected to the inlet of the first deaerator 9, realizing that the local boiler (the first boiler 1 of the first unit) uses the auxiliary steam of the adjacent unit boiler (the second boiler 12 of the second unit) for primary heating, preheating with the auxiliary steam of the adjacent unit boiler, reducing the heat input required by the local boiler during the startup phase, thereby reducing the consumption of fuel oil and coal, and at the same time reducing the power consumption of the main auxiliary equipment. The outlet of the high-pressure cylinder 13 of the second steam turbine is connected to the inlet of the first high-pressure heater 11, realizing that the local boiler uses the auxiliary steam of the adjacent unit boiler for secondary heating, further reducing the overall cost of starting the local boiler, while improving the energy efficiency level and fast start-stop performance of the unit. Through secondary heating, the heat of the adjacent unit boiler can be more fully utilized, improving the overall efficiency of the system.

[0040] In an embodiment, the drain water of the first high-pressure heater 11 flows by gravity to the first deaerator 9, and the drain water of the first low-pressure heater 8 flows by gravity to the first condenser 6.

[0041] In one embodiment, the first steam path includes a first high-pressure cylinder 2 of a steam turbine, a first intermediate-pressure cylinder 3 of the steam turbine, and a first low-pressure cylinder 4 of the steam turbine, which are sequentially arranged, coaxially connected, and drive a first generator 5 to generate electricity. The first boiler 1 is provided with a first reheater. The outlet of the first high-pressure cylinder 2 of the steam turbine is connected to the inlet of the first reheater, the outlet of the first reheater is connected to the inlet of the first intermediate-pressure cylinder 3 of the steam turbine, the outlet of the first intermediate-pressure cylinder 3 of the steam turbine is connected to the inlet of the first low-pressure cylinder 4 of the steam turbine, and the outlet of the first low-pressure cylinder 4 of the steam turbine is connected to the inlet of the first condenser 6. In the first unit, the superheated steam generated by the first boiler 1 first enters the first high-pressure cylinder 2 of the steam turbine, then enters the first reheater for heating, and then sequentially enters the first intermediate-pressure cylinder 3 of the steam turbine and the first low-pressure cylinder 4 of the steam turbine, and finally enters the first condenser 6 for condensation, making full use of the energy of the steam and ensuring the power generation efficiency of the first unit.

[0042] In the first unit, the outlet of the first condenser 6 is connected to the inlet of the first condensate pump 7, the outlet of the first condensate pump 7 is connected to the inlet of the first low-pressure heater 8, the outlet of the first low-pressure heater 8, the extraction outlet of the first intermediate-pressure cylinder 3 of the steam turbine, the drain outlet of the first high-pressure heater 11, and the outlet of the second boiler 12 are all connected to the inlet of the first deaerator 9, the outlet of the first deaerator 9 is connected to the inlet of the first feed water pump 10, the outlet of the first feed water pump 10, the extraction outlet of the first high-pressure cylinder 2 of the steam turbine, and the outlet of the second high-pressure cylinder 13 of the steam turbine are all connected to the inlet of the first high-pressure heater 11, and the outlet of the first high-pressure heater 11 is connected to the inlet of the first boiler 1, realizing multiple heat transfer paths and efficient heat utilization methods within the system, optimizing heat distribution and circulation, improving heat utilization efficiency and the overall energy efficiency of the system, enhancing the adaptability, flexibility, stability, and reliability of the system to different operating conditions and load demands, and at the same time reducing the operating cost.

[0043] In one embodiment, the inlet of the first deaerator 9 is respectively connected to the outlet of the first low-pressure heater 8, the extraction outlet of the first intermediate-pressure cylinder 3 of the steam turbine, and the outlet of the second boiler 12, and the outlet of the first deaerator 9 is connected to the first high-pressure heater 11. In the first deaerator 9, it can be heated by the extraction steam of the first intermediate-pressure cylinder 3 of the steam turbine and also by the steam of the second boiler 12, improving the primary preheating capacity, realizing the diversity of heat transfer, and enabling the system to better adapt to different operating conditions and load demands.

[0044] In one embodiment, the inlet of the first high-pressure heater 11 is respectively connected to the outlet of the first deaerator 9, the extraction outlet of the high-pressure cylinder 2 of the first steam turbine, and the outlet of the high-pressure cylinder 13 of the second steam turbine. The outlet of the first high-pressure heater 11 is connected to the inlet of the first boiler 1. Inside the first high-pressure heater 11, it can be heated by the extraction steam of the high-pressure cylinder 2 of the first steam turbine and also by the steam of the high-pressure cylinder 13 of the second steam turbine, improving the secondary preheating capacity, realizing the optimization of the heat transfer path of the system, improving the utilization rate of heat, and at the same time reducing the operating cost of the system.

[0045] The outlet of the second boiler 12 is connected to the inlet of the first deaerator 9. The outlet of the first deaerator 9 is connected to the inlet of the first feed water pump 10. The outlet of the first feed water pump 10 is connected to the inlet of the first high-pressure heater 11. The outlet of the first high-pressure heater 11 is connected to the inlet of the first boiler 1. The above heat transfer method realizes a heat circulation system with the coupling of the first unit and the second unit, which can utilize heat more efficiently and improve the overall energy efficiency of the system at the same time. The outlet of the second boiler 12 is connected to the inlet of the high-pressure cylinder 13 of the second steam turbine. The outlet of the high-pressure cylinder 13 of the second steam turbine is connected to the inlet of the first high-pressure heater 11. The outlet of the first high-pressure heater 11 is connected to the inlet of the first boiler 1. The above heat transfer method realizes another efficient heat utilization method with the coupling of the first unit and the second unit, which can not only utilize heat more efficiently, improve the overall energy efficiency, but also flexibly adopt a variety of different operating strategies according to the actual situation, improving the flexibility and adaptability of the system.

[0046] In one embodiment, the second return water path includes a second condensate pump 18, a second low-pressure heater 19, a second deaerator 20, a second feed water pump 21, and a second high-pressure heater 22 arranged in sequence. In the second unit, the condensate water of the second condenser 17 is pumped by the second condensate pump 18, first enters the second low-pressure heater 19 for preheating, then enters the second deaerator 20 for deaeration and other treatments, and then enters the second high-pressure heater 22 for further preheating under the action of the second feed water pump 21, and finally enters the second boiler 12. The drain water of the second high-pressure heater 22 flows by gravity to the second deaerator 20, and the drain water of the second low-pressure heater 19 flows by gravity to the second condenser 17.

[0047] As Figure 1As shown in the figure, the present invention provides a power system, including a power generation system and a control system. The power generation system includes the adjacent unit steam heating power generation system and the new energy power generation system as described above. The new energy power generation system may include a photovoltaic power generation system 24 and a wind power generation system 23. The control system includes a central control system 29, a power plant real-time monitoring system 27, and a new energy access and monitoring system 28. The adjacent unit steam heating power generation system transmits electricity to the power grid 25 through the power plant real-time monitoring system 27. The new energy power generation system transmits electricity to the power grid 25 through the new energy access and monitoring system 28. The power grid 25 transmits electricity to the electricity consumers 26 through the central control system 29. The central control system 29 is connected to the power plant real-time monitoring system 27 and the new energy access and monitoring system 28 respectively through negative feedback regulation.

[0048] In one embodiment, in the adjacent unit steam heating power generation system, both the first unit and the second unit adopt air-cooled coal-fired generating units. The high-pressure cylinder 2 of the first steam turbine, the intermediate-pressure cylinder 3 of the first steam turbine, and the low-pressure cylinder 4 of the first steam turbine are coaxially connected to drive the first generator 5 to generate electricity. The superheated steam outlet of the first boiler 1 is connected to the inlet of the high-pressure cylinder 2 of the first steam turbine, the outlet of the high-pressure cylinder 2 of the first steam turbine is connected to the reheater of the first boiler 1, the outlet of the reheater of the first boiler 1 is connected to the intermediate-pressure cylinder 3 of the first steam turbine, and the intermediate-pressure cylinder 3 of the first steam turbine, the low-pressure cylinder 4 of the first steam turbine, and the first condenser 6 are connected in sequence. The outlet pipeline of the water tank of the first condenser 6 is connected to the first condensate pump 7, the first low-pressure heater 8, the first deaerator 9, the first feed water pump 10, and the first high-pressure heater 11 in sequence. The first low-pressure heater 8 uses the extraction steam of the low-pressure cylinder 4 of the first steam turbine as the heat source, the first deaerator 9 uses the extraction steam of the intermediate-pressure cylinder 3 of the first steam turbine and the steam of the second boiler 12 as the heat source, and the first high-pressure heater 11 uses the extraction steam of the high-pressure cylinder 2 of the first steam turbine and the reheated cold-end steam of the second boiler 12 as the heat source. The drain water of the first high-pressure heater 11 and the first low-pressure heater 8 flows by gravity step by step and is respectively collected in the first deaerator 9 and the water tank of the first condenser 6. The high-pressure cylinder 13 of the second steam turbine, the intermediate-pressure cylinder 14 of the second steam turbine, and the low-pressure cylinder 15 of the second steam turbine are coaxially connected to drive the second generator 16 to generate electricity. The superheated steam outlet of the second boiler 12 is connected to the inlets of the high-pressure cylinder 13 of the second steam turbine and the first deaerator 9, the outlet of the high-pressure cylinder 13 of the second steam turbine is connected to the reheater of the second boiler 12 and the first high-pressure heater 11, the outlet of the reheater of the second boiler 12 is connected to the intermediate-pressure cylinder 14 of the second steam turbine, and the intermediate-pressure cylinder 14 of the second steam turbine, the low-pressure cylinder 15 of the second steam turbine, and the second condenser 17 are connected in sequence. The outlet pipeline of the water tank of the second condenser 17 is connected to the second condensate pump 18, the second low-pressure heater 19, the second deaerator 20, the second feed water pump 21, and the second high-pressure heater 22 in sequence. The second high-pressure heater 22, the second deaerator 20, and the second low-pressure heater 19 respectively use the extraction steam matching the steam turbine pressure as the heat source. The drain water of the second high-pressure heater 22 and the second low-pressure heater 19 flows by gravity step by step and is respectively collected in the second deaerator 20 and the second condenser 17.

[0049] The precise regulation of the thermal power units in the power system of the present invention to adapt to the characteristics of new energy can greatly improve the consumption of new energy, optimize the energy structure, and reduce carbon emissions; the thermal power responds quickly to the fluctuations of new energy, and at the same time increases the peak shaving depth to ensure the stability and reliability of power supply; the adjacent unit heating power generation system realizes cascade utilization of heat, recovers waste heat and reduces costs; reasonably uses the steam of the adjacent unit boiler for heating, reduces the start-up energy consumption of the local boiler, improves the energy efficiency and start-stop performance of the unit, and can also reduce thermal stress and extend the equipment life, contributing to the sustainable development of the power industry, and has high application and promotion value.

[0050] With the rapid development of new energy power generation, especially in some areas rich in new energy resources, new energy power generation (such as photovoltaic power generation and wind power generation) can supply a large amount of electricity during a certain period of the day, while its power generation capacity is weak during other periods. Due to the instability of the electricity provided by new energy, it is difficult to supply new energy electricity to the power grid 25, resulting in insufficient consumption of new energy electricity and waste of new energy electricity. By adopting the power system of the present invention, at least two groups of units can be used in the adjacent unit steam heating power generation system to adopt a shift start-stop operation strategy, which can make full use of new energy electricity while ensuring the stability and economy of power supply. This strategy aims to form a good complementarity with new energy power generation by reasonably arranging the start-stop of coal-fired generating units, thereby improving the operation efficiency of the entire power system.

[0051] In one embodiment, as Figures 1 to 4 shown, the application example of the power system provided by the present invention is as follows: A certain place is selected as a typical application scenario, and its daily load curve is as Figure 2 shown, with obvious characteristics. Specifically, during a period of about 8 hours during the day, due to sufficient sunlight and strong wind, photovoltaic power generation and wind power generation perform excellently, and their new energy power generation is as Figure 3 shown, and the new energy power generation increases significantly. To make full use of this advantageous resource, using the power system of the present invention, during this period, the output of the coal-fired generating unit is reduced, and one of the two air-cooled coal-fired generating units is shut down, thereby increasing the consumption ratio of new energy and realizing green and low-carbon power supply. In the afternoon, the output of new energy remains basically unchanged, but the electricity consumption required by the electricity users 26 decreases. Enabling a single unit can further increase the peak shaving depth. During the night period, since the new energy power generation is small, in order to ensure the stable supply of electricity, the coal-fired generating unit needs to undertake the main power generation task. Due to the existence of the adjacent unit steam heating power generation system, the units with shift start-stop can be preheated to a temperature close to that required for hot state flushing through the steam of the adjacent unit boiler before the boiler is ignited, greatly reducing the fuel consumption at the initial stage of ignition and directly reducing the fuel cost. At the same time, during the process, by precisely controlling the feed water temperature, the problem of thermal shock of the boiler heating surface caused by sudden change of water temperature is avoided, the risk of equipment damage caused by excessive thermal stress is reduced, the thermal shock and temperature fluctuation are reduced, the service life of the boiler and its auxiliary equipment is extended, the long-term operation and maintenance cost is reduced, the boiler startup time is shortened, and the unit can be put into operation faster, thereby improving the production efficiency of the power plant.

[0052] During the normal operation of the power system, the new energy access and monitoring system 28 continuously collects the output data of new energy and meteorological information. The central control system 29 updates and analyzes the data at regular time intervals, and judges whether to issue an instruction to the power plant real-time monitoring system 27 to perform the shift start-stop operation of the unit according to the preset algorithm and strategy.

[0053] When the central control system 29 determines that the operating state of the unit needs to be adjusted, the central control system 29 first sends an instruction to the power plant real-time monitoring system 27 to gradually adjust the load and operating parameters of the unit to prepare for shutdown or startup. At the same time, the adjacent unit steam heating power generation system starts the corresponding heating program to adjust the flow rate and temperature of the heating medium, ensuring that the temperature of the shutdown unit (such as Figure 1 the first unit is shut down and the second unit remains in operation in

[0054] is stable within a suitable range and can quickly reach the predetermined temperature conditions during startup.

[0055] During the entire operation process, the power plant real-time monitoring system 27 monitors the operating state of each unit and the working conditions of the adjacent unit steam heating power generation system in real time, and the new energy access and monitoring system 28 monitors the output changes of new energy. Operators can manually intervene and adjust the two through the central control system 29 according to the actual situation, such as pausing or starting a certain device and modifying control parameters in case of emergency. However, such manual operations require strict permission authentication and operation records to ensure the safety and stability of the system.

[0056] Taking a 660MW supercritical unit as an example, the shift start-stop strategy of the present invention is further elaborated. Under the hot start condition of this unit, the corresponding shutdown time is 1 to 10 hours, which highly coincides with the time length of the new energy power generation peak. Therefore, the present invention proposes an efficient peak shaving scheme for shift start-stop of multiple units: during the day of the new energy power generation peak period, by appropriately shutting down some of such units, the power output can be flexibly adjusted to maximize the utilization of new energy power and further increase the consumption of new energy. Taking the daily load after new energy consumption in a certain place as an example, its curve is as Figure 4As shown. At the same time, improve the operating economy of coal-fired power units and reduce the energy consumption and wear caused by long-term continuous operation. When the output of new energy weakens, gradually start other units to ensure the stability and reliability of power supply. This strategy is not only applicable to the single-unit operation scenario. In a power plant with a capacity of 4×660 MW, by shutting down one or two units, the peak shaving depth can be reduced to 15% and 10% of the full-plant rated load respectively, significantly improving the peak shaving capacity, enabling it to cope with the volatility and uncertainty of new energy power generation, and ensuring the stable operation and efficient power supply of the power system. For a power plant with a capacity of 4×660 MW, after adopting the shift-based peak shaving strategy while keeping the total output of the power plant unchanged, compared with all 4 units operating at the lowest load, the critical times for shutting down one and two units are 4.81 hours and 6.57 hours respectively, and the total coal savings are 184.84 t and 270.49 t respectively, saving about 70,600 yuan and 46,300 yuan. Thus, it can be seen that the present invention has significant advantages in increasing the proportion of new energy consumption, enhancing the peak shaving depth of thermal power units, and realizing the feasibility and practicality of unit shift start-stop.

[0057] In the present invention, specific examples are used to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A steam heating power generation system for an adjacent machine, characterized in that: include: A first unit, the first unit comprising a first steam path and a first water return path, the inlet of the first steam path being connected to the outlet of the first boiler (1), the outlet of the first steam path being connected to the inlet of the first condenser (6), the inlet of the first water return path being connected to the outlet of the first condenser (6), and the outlet of the first water return path being connected to the inlet of the first boiler (1); A second unit, the second unit comprising a second steam path and a second water return path, the inlet of the second steam path being connected to the outlet of the second boiler (12), the outlet of the second steam path being connected to the inlet of the second condenser (17), the inlet of the second water return path being connected to the outlet of the second condenser (17), and the outlet of the second water return path being connected to the inlet of the second boiler (12); a first coupling pipeline, wherein an inlet of the first coupling pipeline is connected to a first branch port of the second steam path, and an outlet of the first coupling pipeline is connected to a first preheating position of the first water return path; And a second coupling pipeline, the inlet of the second coupling pipeline is connected to the second branch port of the second steam path, and the outlet of the second coupling pipeline is connected to the second preheating position of the second return water path; the first branch port is located upstream of the second branch port, and the first preheating position is located upstream of the second preheating position.

2. The adjacent machine steam heating power generation system according to claim 1, characterized in that: The second steam path includes a second steam turbine high-pressure cylinder (13), a second steam turbine intermediate-pressure cylinder (14) and a second steam turbine low-pressure cylinder (15) arranged in sequence, the first branch port is connected to the outlet of the second boiler (12), and the second branch port is connected to the outlet of the second steam turbine high-pressure cylinder (13).

3. The adjacent machine steam heating power generation system according to claim 2 is characterized in that: The second boiler (12) is provided with a second reheater, the outlet of the second steam turbine high-pressure cylinder (13) is connected to the inlet of the second reheater, the outlet of the second reheater is connected to the inlet of the second steam turbine intermediate-pressure cylinder (14), the outlet of the second steam turbine intermediate-pressure cylinder (14) is connected to the inlet of the second steam turbine low-pressure cylinder (15), and the outlet of the second steam turbine low-pressure cylinder (15) is connected to the inlet of the second condenser (17).

4. The adjacent machine steam heating power generation system according to claim 2 is characterized in that: The first water return path comprises a first condensate pump (7), a first low-pressure heater (8), a first deaerator (9), a first feed water pump (10) and a first high-pressure heater (11) which are arranged in sequence, the first preheating position is the first deaerator (9), and the second preheating position is the first high-pressure heater (11).

5. The adjacent machine steam heating power generation system according to claim 4 is characterized in that: The drain of the first high-pressure heater (11) flows by gravity to the first deaerator (9), and the drain of the first low-pressure heater (8) flows by gravity to the first condenser (6).

6. The adjacent machine steam heating power generation system according to claim 4, characterized in that: The first steam path comprises a first steam turbine high-pressure cylinder (2), a first steam turbine intermediate-pressure cylinder (3) and a first steam turbine low-pressure cylinder (4) arranged in sequence; the first boiler (1) is provided with a first reheater, the outlet of the first steam turbine high-pressure cylinder (2) is connected to the inlet of the first reheater, the outlet of the first reheater is connected to the inlet of the first steam turbine intermediate-pressure cylinder (3), the outlet of the first steam turbine intermediate-pressure cylinder (3) is connected to the inlet of the first steam turbine low-pressure cylinder (4), and the outlet of the first steam turbine low-pressure cylinder (4) is connected to the inlet of the first condenser (6).

7. The adjacent machine steam heating power generation system according to claim 6, characterized in that: The inlet of the first deaerator (9) is respectively connected to the outlet of the first low-pressure heater (8), the steam extraction outlet of the first steam turbine intermediate-pressure cylinder (3) and the outlet of the second boiler (12), and the outlet of the first deaerator (9) is connected to the first high-pressure heater (11).

8. The adjacent machine steam heating power generation system according to claim 6, characterized in that: The inlet of the first high-pressure heater (11) is respectively connected to the outlet of the first deaerator (9), the exhaust outlet of the first steam turbine high-pressure cylinder (2) and the outlet of the second steam turbine high-pressure cylinder (13), and the outlet of the first high-pressure heater (11) is connected to the inlet of the first boiler (1).

9. The adjacent machine steam heating power generation system according to claim 6, characterized in that: The second return water path includes a second condensate pump (18), a second low-pressure heater (19), a second deaerator (20), a second feed water pump (21) and a second high-pressure heater (22) which are arranged in sequence, the drain of the second high-pressure heater (22) flows by gravity to the second deaerator (20), and the drain of the second low-pressure heater (19) flows by gravity to the second condenser (17).

10. A power system, characterized in that: include: A power generation system, the power generation system comprising the adjacent machine steam heating power generation system and the new energy power generation system according to any one of claims 1 to 9; and a control system, the control system comprising a central control system (29), a power plant real-time monitoring system (27) and a new energy access and monitoring system (28), the adjacent steam heating power generation system transmits electricity to a power grid (25) through the power plant real-time monitoring system (27), the new energy power generation system transmits electricity to a power grid (25) through the new energy access and monitoring system (28), the power grid (25) transmits electricity to an electricity user (26) through the central control system (29), and the central control system (29) is connected to the power plant real-time monitoring system (27) and the new energy access and monitoring system (28) respectively through negative feedback regulation.

Images