Peak-shaving heat-storage thermal power unit thermodynamic system and operation method thereof

Abstract

The invention discloses a peak regulation heat storage thermal power unit thermodynamic system and an operation method thereof, and belongs to the technical field of thermal power generation. Comprising a boiler, a turbine high-pressure cylinder, a turbine intermediate-pressure cylinder and a turbine low-pressure cylinder. A first outlet of the boiler is connected with a turbine high-pressure cylinder, and an outlet of the turbine high-pressure cylinder is connected to a second inlet of the boiler; a second outlet of the boiler is connected with a steam turbine intermediate-pressure cylinder, a first outlet of the steam turbine intermediate-pressure cylinder is sequentially connected with a heat storage unit and a feed water heater, and the feed water heater is connected to a first inlet of the boiler; a second outlet of the turbine intermediate-pressure cylinder is sequentially connected with a turbine low-pressure cylinder, a condenser and a condensate pump; an outlet of the condensate pump is divided into two paths, one path is sequentially connected with a condensate heater and a deaerator, and the deaerator is connected to a feed water heater; the other path of the condensate pump outlet is connected to the heat storage unit. And efficient combination of a heat storage technology and a thermal power generating unit thermodynamic system is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation, and relates to a thermal system of a peak-shaving thermal storage thermal power unit and an operation method thereof. Background Art

[0002] In the context of energy structure transformation and upgrading, the proportion of renewable energy power generation has increased year by year, especially the rapid development of clean energy such as wind power and photovoltaic power. However, renewable energy power generation is intermittent and unstable, and its output is greatly affected by natural factors such as weather, which puts higher requirements on the peak load regulation capacity of the power grid. As the main body of traditional power supply, thermal power units need to continue to undertake basic power supply tasks during the transformation of energy structure, and also need to supplement power in time when renewable energy output is insufficient, and reduce output when renewable energy output is at its peak to make room for renewable energy power sources.

[0003] With the rapid development of renewable energy generation, the demand for peak load regulation of power grids is increasing. Especially during the period of wind power and photovoltaic power generation, the power grid needs to quickly adjust the load to balance the fluctuation of renewable energy generation. However, the traditional peak load regulation method of reducing the load of conventional power plants can no longer meet the increasing demand for wind power. Therefore, it is necessary to seek more ideas for wind power acceptance and improve the peak load regulation capacity of the power grid.

[0004] In order to adapt to the development needs of renewable energy power generation, thermal power units need to conduct research on deep peak-shaving technology. Deep peak-shaving technology refers to the technology that enables thermal power units to operate safely and stably under lower loads. Through deep peak-shaving, thermal power units can reduce output when renewable energy output is at its peak to make room for renewable energy power sources; at the same time, they can replenish electricity in time when renewable energy output is insufficient to ensure the safe and stable operation of the power grid. However, thermal power units will face a series of technical challenges during deep peak-shaving, such as boiler combustion stability, turbine operating efficiency, and normal operation of environmental protection systems.

[0005] In order to solve the problems faced by thermal power units during deep peak regulation and improve the peak regulation capacity of the power grid, thermal storage peak regulation technology has been introduced. Thermal storage peak regulation technology uses thermal storage devices to convert electrical energy into thermal energy and store it during the off-peak period of the power grid, and releases the stored thermal energy during the peak period of the power grid to meet the peak regulation needs of the power grid. However, the existing technology is difficult to efficiently combine thermal storage technology with the thermal system of thermal power units, resulting in serious waste of thermal energy and safety hazards. Summary of the invention

[0006] The purpose of the present invention is to provide a peak-shaving heat storage thermal power unit thermal system and an operation method thereof, so as to solve the technical problems in the prior art that it is difficult to efficiently combine heat storage technology with the thermal system of a thermal power unit, heat energy is seriously wasted, and there are safety hazards.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a thermal system of a peak-shaving heat storage thermal power unit, comprising a boiler, a turbine high-pressure cylinder, a turbine intermediate-pressure cylinder and a turbine low-pressure cylinder; the first outlet of the boiler is connected to the turbine high-pressure cylinder, and the outlet of the turbine high-pressure cylinder is connected to the second inlet of the boiler; the second outlet of the boiler is connected to the turbine intermediate-pressure cylinder, and the first outlet of the turbine intermediate-pressure cylinder is connected in sequence to a heat storage unit and a feed water heater, and the feed water heater is connected to the first inlet of the boiler; the second outlet of the turbine intermediate-pressure cylinder is connected in sequence to the turbine low-pressure cylinder, a condenser and a condensate pump; the outlet of the condensate pump is divided into two routes, one route is connected in sequence to the condensate heater and a deaerator, and the deaerator is connected to the feed water heater; the other route of the condensate pump outlet is connected to the heat storage unit.

[0008] Furthermore, the heat storage unit includes a heat storage water tank, a heat exchanger and a heat storage deoxygenated water tank; the heat storage deoxygenated water tank contains water, and the first outlet of the intermediate pressure cylinder of the steam turbine is connected to the water in the heat storage deoxygenated water tank through a pipeline; an outlet and an inlet are provided at the bottom of the heat storage deoxygenated water tank, the inlet is connected to the condensate pump through a pipeline, and the outlet is connected to the feed water heater through a pipeline; one side of the heat storage deoxygenated water tank is also connected in sequence with a heat exchanger and a heat storage water tank, and the heat storage water tank can store surplus heat energy in the heat storage deoxygenated water tank.

[0009] Furthermore, a submerged jet nozzle device is installed at the outlet of the pipeline connecting the first outlet of the intermediate pressure cylinder of the steam turbine and the heat storage deoxygenated water tank.

[0010] Furthermore, a second feed water pump is installed on the pipeline between the bottom outlet of the thermal storage deoxygenated water tank and the feed water heater.

[0011] Furthermore, the heat exchanger is a plate heat exchanger.

[0012] Furthermore, a first feedwater pump is installed on the connecting pipe between the deaerator and the feedwater heater.

[0013] Furthermore, a plurality of condensate water heaters are provided and connected in series in sequence to heat the condensate water step by step.

[0014] Furthermore, a plurality of feed water heaters are provided and connected in series to heat the feed water step by step.

[0015] In a second aspect, the present invention provides a method for operating the thermal system of the peak load storage thermal power unit, comprising the following steps: When there is no peak load demand, the thermal power unit is in a 60% to 70% load power generation state. The steam generated by the boiler passes through the high-pressure cylinder of the steam turbine, the medium-pressure cylinder of the steam turbine and the low-pressure cylinder of the steam turbine in sequence. The exhaust steam of the low-pressure cylinder of the steam turbine enters the condenser and condenses into water in the condenser. The water then passes through the condensate pump, condensate heater, deaerator and feed water heater in sequence and finally returns to the boiler. When the thermal power unit is in peak load operation, it is in a power generation state below 60%, and the surplus heat energy is stored through the thermal storage unit; When the thermal power unit is operating at its peak, it is in a state of power generation with a load of more than 70%. The steam generated by the boiler passes through the high-pressure cylinder of the turbine, the intermediate-pressure cylinder of the turbine and the low-pressure cylinder of the turbine, the condenser, the condensate pump, the condensate heater, the deaerator and the feed water heater in turn, and finally returns to the boiler; the external heat demand is supplied by the heat stored in the heat storage unit.

[0016] Furthermore, when the thermal power unit is in peak load operation and is in a power generation state with a load below 60%, the step of storing the surplus thermal energy through the heat storage unit specifically includes: When the peak load regulation demand of the thermal power unit is large and the load is below 40%, the steam generated by the boiler enters the high-pressure cylinder and the intermediate-pressure cylinder of the steam turbine, and the exhaust steam of the intermediate-pressure cylinder of the steam turbine is all discharged into the thermal storage and deoxygenation water tank; the water level in the thermal storage and deoxygenation water tank is kept stable, and the flow rate of the submerged jet nozzle device at the inlet of the thermal storage and deoxygenation water tank and the outlet connected to the second feed water pump is balanced; When the peak-shaving demand of the thermal power unit is relatively small, it is in a load power generation state of 40%~60%. The steam generated by the boiler enters the high-pressure cylinder and the intermediate-pressure cylinder of the turbine. Part of the exhaust steam from the intermediate-pressure cylinder of the turbine is passed into the heat storage deaerator water tank to store the heat; the other part of the exhaust steam from the intermediate-pressure cylinder of the turbine passes through the low-pressure cylinder of the turbine, the condenser and the condensate pump in turn; the condensate is divided into two paths through the condensate pump, one path passes through the condensate pump, the condensate heater, the deaerator, the first feed water pump and the water heater in turn, and the other path passes through the condensate pump, the second feed water pump and the water heater in turn, and the two paths finally return to the boiler together.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a thermal system for peak-shaving heat storage thermal power generation units and an operation method thereof. Most of the exhaust steam of the medium-pressure cylinder on the existing thermal power generation system (only the minimum flow required by the low-pressure cylinder is left) is introduced into a heat storage deoxygenated water tank (low-pressure cylinder cutting can be basically realized), and the peak-shaving depth of the unit can be increased when needed. The cold source loss of the existing thermal power generation system, that is, the exhaust steam latent heat of the condenser, is greatly reduced, and this part of heat is transferred to the heat storage unit for storage, and heat is supplied to the outside when needed, so that the cold source loss is converted into the benefit of heating. When the steam turbine generator unit needs to reduce the load peak, the present invention reduces the power generation of the unit by reducing the steam intake of the low-pressure cylinder of the steam turbine without changing the original boiler operating load, so as to achieve the purpose of reducing the power on the grid; at the same time, the cold source loss of the condenser can be reduced, and this part of heat can be stored. It breaks through the limitation that the existing thermal power units in the north can only perform zero output of the low-pressure cylinder in the heating season, and can achieve deep peak regulation throughout the year. It has good operation flexibility and peak regulation effect, and is very suitable for the existing electricity spot market rules.

[0018] Furthermore, the present invention uses a heat exchanger to separate the circulation of the hot water storage tank and the heat storage deoxygenated water tank, which can maintain the water quality of the thermal system of the generator set without being affected by the external heat exchange medium. The present invention uses a hot water storage tank to achieve cross-seasonal heat storage, storing the heat of the summer unit for winter heating, and can also provide heating at any time according to actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of a thermal system of a peak-shaving thermal storage thermal power unit according to the present invention.

[0021] Among them: 1- boiler; 2- turbine high-pressure cylinder; 3- turbine medium-pressure cylinder; 4- turbine low-pressure cylinder; 5- feedwater heater; 6- first feedwater pump; 7- deaerator; 8- condensate heater; 9- condenser; 10- heat storage tank; 11- heat exchanger; 12- submerged jet nozzle device; 13- heat storage deaerator tank; 14- condensate pump; 15- second feedwater pump. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0026] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1In view of the problems currently faced by thermal power plants such as peak-shaving and frequency regulation, flexible operation and the need to play a supporting and regulating role in new power systems, the present invention proposes a thermal system for a peak-shaving and heat-storage thermal power unit, comprising a boiler 1, a turbine high-pressure cylinder 2, a turbine intermediate-pressure cylinder 3 and a turbine low-pressure cylinder 4; the first outlet of the boiler 1 is connected to the turbine high-pressure cylinder 2, and the outlet of the turbine high-pressure cylinder 2 is connected to the second inlet of the boiler 1; the second outlet of the boiler 1 is connected to the turbine intermediate-pressure cylinder 3, and the first outlet of the turbine intermediate-pressure cylinder 3 is connected to a heat storage unit and a feedwater heater 5 in sequence, and the feedwater heater 5 is connected to the first inlet of the boiler 1; the second outlet of the turbine intermediate-pressure cylinder 3 is connected to the turbine low-pressure cylinder 4, a condenser 9 and a condensate pump 14 in sequence; the outlet of the condensate pump 14 is divided into two routes, one of which is connected to a condensate heater 8 and a deaerator 7 in sequence, and the deaerator 7 is connected to the feedwater heater 5; the other outlet of the condensate pump 14 is connected to the heat storage unit.

[0029] In this embodiment, the main steam of the boiler 1 enters the high-pressure cylinder 2 of the steam turbine to perform work; the exhaust steam of the high-pressure cylinder 2 of the steam turbine returns to the boiler 1 to be heated again and then enters the intermediate-pressure cylinder 3 of the steam turbine to perform work; the exhaust steam of the intermediate-pressure cylinder 3 of the steam turbine is divided into two paths: one path enters the low-pressure cylinder 4 of the steam turbine to perform work, and the other path enters the heat storage unit; the exhaust steam of the low-pressure cylinder 4 of the steam turbine enters the condenser 9 to condense into condensate, and the condensate can be returned to the boiler through the condensate pump 14, the condensate heater 8, the deaerator 7, the first feed water pump 6, and the feed water heater 5 in sequence; it can also be returned to the boiler through the condensate pump 14, the heat storage unit, and the feed water heater 5 in sequence; The system of this embodiment configures new thermal and heat storage equipment around the original thermal system of the thermal power unit, and connects it with the original thermal system to form a thermal system of the thermal power unit that can achieve peak load regulation and heat storage. When the unit needs to reduce the load for peak regulation, the thermal power unit will reduce the grid-connected power by increasing the steam extraction of the original steam turbine intermediate pressure cylinder 3 without changing the original boiler operating load; at the same time, since the steam intake of the steam turbine low-pressure cylinder 4 is reduced, the cold source loss is greatly reduced. This system stores the heat of the reduced cold source loss in the heat storage unit and supplies heat to the outside when needed; in this way, the low-pressure cylinder of the unit can achieve zero output throughout the year, increasing the peak regulation depth and operation flexibility of the unit.

[0030] The advantage of doing this is that the load changes of the thermal power units are not affected by the minimum stable combustion load of the power station boiler, the peak regulation depth of the thermal power units is increased, the stable and safe operation of the unit's boilers and steam turbines is guaranteed, and the service life of the boilers and steam turbines is increased.

[0031] In a feasible embodiment of the present invention, the heat storage unit includes a heat storage water tank 10, a heat exchanger 11 and a heat storage deoxygenated water tank 13; the heat storage deoxygenated water tank 13 contains water, and the first outlet of the turbine intermediate pressure cylinder 3 is connected to the water in the heat storage deoxygenated water tank 13 through a pipeline; an outlet and an inlet are provided at the bottom of the heat storage deoxygenated water tank 13, the inlet is connected to the condensate pump 14 through a pipeline, and the outlet is connected to the feed water heater 5 through a pipeline; one side of the heat storage deoxygenated water tank 13 is also connected in sequence with the heat exchanger 11 and the heat storage water tank 10, and the heat storage water tank 10 can store surplus heat energy in the heat storage deoxygenated water tank 13.

[0032] In this embodiment, the water level in the heat storage deoxygenated water tank 13 is kept constant, and the heat source for heating the water inside the water tank is the exhaust steam of the intermediate pressure cylinder, which undergoes phase change heat exchange with the water in the water tank through the immersed jet device 12. The water temperature of the water tank is distributed in layers, with high temperature at the top and low temperature at the bottom. The water temperature at the bottom of the water tank matches the inlet temperature of the feed water heater 5. Since the water temperature at the top of the water tank is higher, the water circulates internally in the water pipe according to the temperature. Figure 1 The heat storage and deoxygenation water tank 13 has two functions: one is to thermally deoxygenate the water in the water tank, and the other is to achieve a certain heat storage function. The water temperature distribution of the hot water storage tank 10 is also high at the top and low at the bottom. The water circulates inside the tank according to the Figure 1 The heat storage tank 10 is a large container of water, which can realize the cross-season heat storage function through anti-seepage, heat preservation and reasonable water distribution. In a feasible embodiment of the present invention, a second feed water pump 15 is installed on the pipeline between the bottom outlet of the heat storage deoxygenated water tank 13 and the feed water heater 5. A first feed water pump 6 is installed on the connecting pipeline between the deaerator 7 and the feed water heater 5. The heat exchanger 11 is preferably a plate heat exchanger but is not limited to it.

[0033] In a feasible embodiment of the present invention, the condensate heaters 8 are provided in a plurality, preferably 4, which are connected in series in sequence, and are used to heat the condensate step by step; the heating heat source is the low-pressure cylinder extraction steam (not marked in the figure), and the condensate temperature increases step by step from the condensate pump 14 to the deaerator 7. The feed water heaters 5 are provided in a plurality, preferably 3, which are connected in series in sequence, and are used to heat the feed water step by step; the heating heat source is the high- and medium-pressure cylinder extraction steam (not marked in the figure), and the feed water temperature increases step by step from the deaerator 7 to the boiler 1;.

[0034] The embodiment of the present invention discloses a method for operating the thermal system of the peak-shaving thermal power generation unit, comprising the following steps: 1. The thermal power units are operating normally.

[0035] When there is no peak-shaving demand, the thermal power unit is in a high-load power generation state. The steam generated by the boiler 1 passes through the turbine high-pressure cylinder 2, the turbine intermediate-pressure cylinder 3 and the turbine low-pressure cylinder 4 in sequence. The exhaust steam of the turbine low-pressure cylinder 4 enters the condenser 9 and condenses into water in the condenser 9. Then the water passes through the condensate pump 14, the condensate heater 8, the deaerator 7 and the feed water heater 5 in sequence, and finally returns to the boiler 1; the working medium circulates according to (boiler 1-turbine high-pressure cylinder 2-turbine intermediate-pressure cylinder 3-turbine low-pressure cylinder 4-condenser 9-condensate pump 14-condensate heater 8-deaerator 7-first feed water pump 6-feed water heater 5-boiler 1), and the operating state of the above-mentioned units is basically at a power generation load of more than 60%-70%.

[0036] 2. Peak-shaving operation of thermal power units.

[0037] When the load power generation is below 60%, the surplus thermal energy is stored through the thermal storage unit.

[0038] 3. Thermal power units operate at peak levels.

[0039] The steam generated by boiler 1 passes through turbine high pressure cylinder 2, turbine intermediate pressure cylinder 3 and turbine low pressure cylinder 4, condenser 9, condensate pump 14, condensate heater 8, deaerator 7 and feed water heater 5 in sequence, and finally returns to boiler 1; the external heat demand is supplied by the heat stored in the thermal storage unit, reducing the steam extraction of the unit, and achieving the purpose of increasing and peaking the online power. The operating state of the above units is basically at more than 70% of the power generation load.

[0040] In a feasible implementation manner of the present invention, the step of peak load operation of the thermal power unit specifically includes: When the peak load demand of the thermal power unit is large, it is in the load power generation state below 40%. The steam generated by the boiler 1 enters the high-pressure cylinder 2 and the intermediate-pressure cylinder 3 of the steam turbine. The exhaust steam of the intermediate-pressure cylinder 3 of the steam turbine is all discharged into the heat storage deoxygenation water tank 13 (only the minimum flow of the low-pressure cylinder 4 of the steam turbine is retained), and the low-pressure cylinder is zero output; the water level in the heat storage deoxygenation water tank 13 is kept stable, and the flow at the inlet submerged jet nozzle device 12 of the heat storage deoxygenation water tank 13 and the outlet connected to the second feed water pump 15 are balanced; due to the reduction of cold source loss, if all the heat in the heat storage deoxygenation water tank 13 is sent back to the thermal system of the unit, it will destroy the thermal system balance of the original unit. Therefore, the heat exchanger 11 is used to send the surplus heat to the heat storage tank for storage. The working medium circulates according to (boiler 1-turbine high-pressure cylinder 2-turbine intermediate-pressure cylinder 3-submerged jet nozzle device 12-heat storage deoxygenation water tank 13-second feed water pump 15-feed water heater 5-boiler 1).

[0041] When the peak load demand of the thermal power unit is relatively small, it is in a 40% to 60% load power generation state, and the steam generated by the boiler 1 enters the high-pressure cylinder 2 and the intermediate-pressure cylinder 3 of the steam turbine. A part of the exhaust steam of the intermediate-pressure cylinder 3 of the steam turbine is passed into the heat storage deaerator water tank 13 to store the heat; the other part of the exhaust steam of the intermediate-pressure cylinder 3 of the steam turbine passes through the low-pressure cylinder 4 of the steam turbine, the condenser 9 and the condensate pump 14 in sequence; the condensate is divided into two paths through the condensate pump 14, one path passes through the condensate pump 14, the condensate heater 8, the deaerator 7, the first feed water pump 6 and the water heater 5 in sequence, and the other path passes through the condensate pump 14, the second feed water pump 15 and the water heater 5 in sequence, and the two paths finally return to the boiler 1 together.

[0042] The working process / working principle of the present invention is as follows: When the steam turbine generator set needs to reduce the load for peak load regulation, the unit can reduce the power generation of the unit by reducing the steam intake of the low-pressure cylinder 4 of the steam turbine without changing the original boiler operating load, thereby achieving the purpose of reducing the amount of electricity connected to the grid; at the same time, the cold source loss of the condenser 9 can be reduced, and this part of the heat can be stored in the hot water storage tank 10. Due to the setting of the hot water storage tank 10, this system breaks through the existing northern thermal power units can only be low-pressure cylinder zero output in the heating season, can achieve deep peak regulation throughout the year, has good operation flexibility and peak regulation effect, and is very suitable for the existing electricity spot market rules.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A thermal system for peak load storage thermal power generation units, characterized in that: The invention comprises a boiler (1), a steam turbine high-pressure cylinder (2), a steam turbine intermediate-pressure cylinder (3) and a steam turbine low-pressure cylinder (4); the first outlet of the boiler (1) is connected to the steam turbine high-pressure cylinder (2), and the outlet of the steam turbine high-pressure cylinder (2) is connected to the second inlet of the boiler (1); the second outlet of the boiler (1) is connected to the steam turbine intermediate-pressure cylinder (3), and the first outlet of the steam turbine intermediate-pressure cylinder (3) is connected in sequence to a heat storage unit and a feedwater heater (5), and the feedwater heater (5) is connected to the first inlet of the boiler (1); the second outlet of the steam turbine intermediate-pressure cylinder (3) is connected in sequence to the steam turbine low-pressure cylinder (4), a condenser (9) and a condensate pump (14); the outlet of the condensate pump (14) is divided into two paths, one of which is connected in sequence to a condensate heater (8) and a deaerator (7), and the deaerator (7) is connected to the feedwater heater (5); the other outlet of the condensate pump (14) is connected to the heat storage unit.

2. A peak load thermal storage thermal power generation unit thermal system according to claim 1, characterized in that: The heat storage unit comprises a heat storage tank (10), a heat exchanger (11) and a heat storage deoxygenated water tank (13); the heat storage deoxygenated water tank (13) contains water, and a first outlet of the steam turbine intermediate pressure cylinder (3) is connected to the water in the heat storage deoxygenated water tank (13) through a pipeline; an outlet and an inlet are provided at the bottom of the heat storage deoxygenated water tank (13); the inlet is connected to a condensate pump (14) through a pipeline, and the outlet is connected to a feed water heater (5) through a pipeline; one side of the heat storage deoxygenated water tank (13) is also connected in sequence to the heat exchanger (11) and the heat storage tank (10), and the heat storage tank (10) is capable of storing surplus heat energy in the heat storage deoxygenated water tank (13).

3. A peak load thermal storage thermal power generation unit thermal system according to claim 2, characterized in that: An immersed jet nozzle device (12) is installed at the outlet of a pipeline connecting the first outlet of the steam turbine intermediate pressure cylinder (3) and the heat storage deoxygenation water tank (13).

4. A peak load thermal storage thermal power generation unit thermal system according to claim 2, characterized in that: A second feed water pump (15) is installed on the pipeline between the bottom outlet of the heat storage deoxygenated water tank (13) and the feed water heater (5).

5. The peak load storage thermal power system of the thermal power generation unit according to claim 2, characterized in that: The heat exchanger (11) is a plate heat exchanger.

6. A peak load thermal storage thermal power generation unit thermal system according to claim 1, characterized in that: A first feedwater pump (6) is installed on the connecting pipe between the deaerator (7) and the feedwater heater (5).

7. The peak load storage thermal power system of the thermal power generation unit according to claim 1, characterized in that: The condensate water heaters (8) are provided in a plurality and are connected in series in sequence, so as to heat the condensate water step by step.

8. The peak load storage thermal power system of the thermal power generation unit according to claim 1, characterized in that: The feed water heaters (5) are provided in a plurality and are connected in series in sequence, so as to heat the feed water step by step.

9. An operating method for a thermal system of a peak load storage thermal power unit according to any one of claims 1 to 8, characterized in that: The following steps are involved: When there is no peak load regulation demand, the thermal power unit is in a 60% to 70% load power generation state. The steam generated by the boiler (1) passes through the high-pressure cylinder (2) of the steam turbine, the intermediate-pressure cylinder (3) of the steam turbine and the low-pressure cylinder (4) of the steam turbine in sequence. The exhaust steam of the low-pressure cylinder (4) of the steam turbine enters the condenser (9) and condenses into water in the condenser (9). The water then passes through the condensate pump (14), the condensate heater (8), the deaerator (7) and the feed water heater (5) in sequence and finally returns to the boiler (1). When the thermal power unit is in peak load operation, it is in a power generation state below 60%, and the surplus heat energy is stored through the thermal storage unit; When the thermal power unit is in peak operation, it is in a load power generation state of more than 70%. The steam generated by the boiler (1) passes through the high-pressure cylinder (2) of the turbine, the intermediate-pressure cylinder (3) of the turbine and the low-pressure cylinder (4) of the turbine, the condenser (9), the condensate pump (14), the condensate heater (8), the deaerator (7) and the feed water heater (5) in sequence, and finally returns to the boiler (1); the external heat demand is supplied by the heat stored in the thermal storage unit.

10. The method for operating a thermal system of a peak load-shaving thermal storage power unit according to claim 9, characterized in that: When the thermal power unit is in peak load operation and is in a power generation state with a load below 60%, the step of storing the surplus heat energy through the heat storage unit specifically includes: When the peak load demand of the thermal power unit is large and the load is below 40%, the steam generated by the boiler (1) enters the high-pressure cylinder (2) and the intermediate-pressure cylinder (3) of the steam turbine, and the exhaust steam of the intermediate-pressure cylinder (3) of the steam turbine is completely discharged into the heat storage and deoxygenation water tank (13); the water level in the heat storage and deoxygenation water tank (13) is kept stable, and the flow rate at the inlet submerged jet nozzle device (12) of the heat storage and deoxygenation water tank (13) and the outlet connected to the second feed water pump (15) is balanced; When the peak load demand of the thermal power unit is relatively small, it is in a 40% to 60% load power generation state. The steam generated by the boiler (1) enters the high-pressure cylinder (2) and the intermediate-pressure cylinder (3) of the steam turbine. A part of the exhaust steam from the intermediate-pressure cylinder (3) of the steam turbine is passed into the heat storage deaerator water tank (13) to store heat. The other part of the exhaust steam from the intermediate-pressure cylinder (3) of the steam turbine passes through the low-pressure cylinder (4) of the steam turbine, the condenser (9) and the condensate pump (14) in sequence. The condensate is divided into two paths through the condensate pump (14). One path passes through the condensate pump (14), the condensate heater (8), the deaerator (7), the first feed water pump (6) and the water heater (5) in sequence. The other path passes through the condensate pump (14), the second feed water pump (15) and the water heater (5) in sequence. The two paths eventually return to the boiler (1) together.

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