A flexible regulating device for a generator set and a method of operating the same

Abstract

This invention discloses a generator set flexibility adjustment device and its operating method, including a condenser, a regenerative heater, a high-temperature heat storage tank, a partitioned heat exchanger, a low-temperature heat storage tank, an electrothermal conversion device, and a series of control valves. The operating method involves altering the flow paths of exhaust steam and condensate. During peak electricity demand, the low-temperature water in the low-temperature heat storage tank is used to reduce the unit's back pressure and increase power generation, while simultaneously recovering waste heat. High-temperature water in the high-temperature heat storage tank replaces the regenerative extraction steam to heat the condensate, allowing the regenerative extraction steam to enter the low-pressure cylinder and perform work, further increasing power generation. During off-peak electricity demand, the condenser and regenerative extraction steam operate normally, using a portion of the steam entering the low-pressure cylinder and the unit's surplus electricity as driving force to produce high-temperature and low-temperature water, while simultaneously reducing the unit's output. This invention allows the unit to exceed its output limit during peak electricity demand and further reduce load during off-peak electricity demand, enabling wide-range adjustment of the generator set's output while recovering waste heat and improving energy utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy and power technology, and more particularly to a generator set flexibility adjustment device and its operation method that combines high and low temperature energy storage technology with power plant waste heat recovery. Background Technology

[0002] In recent years, the installed capacity and grid-connected electricity of renewable energy have gradually increased. However, due to the randomness and volatility of renewable energy sources such as wind and solar power, the controllability of their power generation is extremely poor, and the pressure on grid regulation is gradually increasing. Thermal power units have stable and easily adjustable loads, so thermal power units are gradually shifting from operating under base load to deep peak shaving, and the requirements for the flexibility of load regulation of thermal power plants are also gradually increasing.

[0003] Currently, peak-shaving methods for thermal power units mainly rely on adjusting turbine output to regulate grid-connected electricity. According to the turbine's operating principle, turbine output is primarily affected by main steam parameters and unit back pressure. However, main steam parameters are limited by boiler load, and unit back pressure is limited by environmental parameters, resulting in a limited range for turbine output adjustment. Furthermore, to improve energy efficiency, modern turbine units are equipped with regenerative steam extraction, but this reduces the unit's power generation, limiting its power generation capacity during peak electricity demand periods. Currently, thermal power plants in northern China primarily use combined heat and power (CHP) units, operating on a "heat-driven power generation" model. Due to heating load limitations, the peak-shaving capacity of CHP units is further restricted.

[0004] Researchers have proposed a "zero-output operation of the low-pressure cylinder" technology, which involves using most of the steam entering the low-pressure cylinder for heating during off-peak electricity periods, retaining only a very small amount of steam for cooling the cylinder. This method can significantly reduce the unit's power generation while ensuring heating capacity during off-peak periods, although some electricity is still fed into the grid. However, it cannot exceed the existing maximum power generation limit during peak electricity periods, indicating a significant untapped potential for peak-shaving capacity. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a generator set flexibility regulation device that combines high and low temperature energy storage technology with power plant waste heat recovery, aiming to maximize the peak-shaving flexibility and economy of power plants.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a generator set flexibility adjustment device, comprising a condenser, a regenerative heater, a partitioned heat exchanger, a high-temperature heat storage module, and an electrothermal conversion device;

[0008] The condenser's steam inlet is connected to the low-pressure cylinder exhaust pipe. The condenser is connected in series with at least one stage of the regenerative heater via a condensate pump. The steam inlets of each stage of the regenerative heater are connected to the corresponding low-pressure cylinder interstage extraction steam pipe. The indirect heat exchanger has four installation positions: the first installation position is that the low-temperature side of the indirect heat exchanger is connected in series on the condensate header between the condenser and the final stage regenerative heater; the second installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel on the condensate header between the condenser and the final stage regenerative heater; the third installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel with a portion of the regenerative heaters; and the fourth installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel with all of the regenerative heaters.

[0009] The high-temperature side outlet of the high-temperature heat storage module is connected to the high-temperature side inlet of the partition wall heat exchanger, and the low-temperature side inlet and outlet of the high-temperature heat storage module are connected to the high-temperature side outlet of the partition wall heat exchanger. A first valve is provided on the connecting pipe between the two. The high-temperature side heat absorption end of the electrothermal conversion device is connected to the high-temperature side inlet and the low-temperature side inlet and outlet of the high-temperature heat storage module. A second valve is provided on the connecting pipe between the two.

[0010] The heat source input terminal of the electrothermal conversion device includes a steam interface, a condensate interface and an electrical interface. The steam interface is connected to the intermediate pressure cylinder exhaust pipe through a third valve. The condensate interface is connected to the condensate header pipe downstream of the primary regenerative heater. The electrical interface is connected to the unit motor through an electrical switch.

[0011] Preferably, when the indirect heat exchanger is in the first installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump, the low-temperature side outlet of the indirect heat exchanger is connected to the inlet pipe of the final stage regenerator, and the indirect heat exchanger is installed on the condensate header.

[0012] When the indirect heat exchanger is in the second installation position, a separate pipe is drawn from the outlet pipe of the condensate pump and connected to the low-temperature side inlet of the indirect heat exchanger, and a separate pipe is drawn from the inlet pipe of the final stage regenerator and connected to the low-temperature side outlet of the indirect heat exchanger.

[0013] When the indirect heat exchanger is in the third installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump or another pipe is led from the outlet pipe of the condensate pump to the low-temperature side inlet of the indirect heat exchanger, and the low-temperature side outlet of the indirect heat exchanger is connected to the condensate mother channel of a certain intermediate stage of the regenerating heater.

[0014] When the indirect heat exchanger is in the fourth installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump or another pipe is led from the outlet pipe of the condensate pump to the low-temperature side inlet of the indirect heat exchanger, and the low-temperature side outlet of the indirect heat exchanger is connected to the condensate main channel downstream of the primary regenerative heater.

[0015] Preferably, the generator set flexibility adjustment device further includes a low-temperature heat storage module and a cooling tower. The low-temperature heat release end of the electrothermal conversion device is connected to the high-temperature inlet and outlet and the low-temperature inlet of the low-temperature heat storage module, and a fourth valve is provided on the connecting pipe between the two. The cooling tower is connected to the condenser through a cooling tower circulating water pump to form a circulation loop, and a fifth valve and a sixth valve are provided on the connecting pipe between the two. At the same time, the outlet of the condenser is also connected to the high-temperature inlet and outlet of the low-temperature heat storage module, and the inlet of the condenser is also connected to the low-temperature outlet of the low-temperature heat storage module, and a seventh valve and an eighth valve are provided on the connecting pipe between the two.

[0016] Preferably, the electric heating device is one or more heating devices, whose heat source comes from electricity during the off-peak period and / or steam extracted from the steam turbine, and the low-temperature heat source comes from waste heat from exhaust steam and / or air.

[0017] In a second aspect, the present invention provides an operating method for a generator set flexibility adjustment device as described in the first aspect, characterized in that it includes:

[0018] (1) During peak electricity load periods:

[0019] The condenser and condensate pump are operating normally. Close the second and third valves, disconnect the power switch, and the electrothermal conversion device stops operating.

[0020] When the indirect heat exchanger is in the first or second installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. The condensate in the indirect heat exchanger is heated and then enters the final stage regenerative heater, and then flows out after passing through each stage of regenerative heater.

[0021] When the indirect heat exchanger is in the third installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. After the condensate in the indirect heat exchanger is heated, it enters the regenerator of a certain stage from the condensate header of the intermediate regenerator, and then flows through the remaining regenerators before flowing out.

[0022] When the indirect heat exchanger is in the fourth installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. After the condensate in the indirect heat exchanger is heated, it flows directly into the condensate header downstream of the primary regenerative heater.

[0023] Open the first valve, and the high-temperature water in the high-temperature heat storage module enters the indirect heat exchanger to heat the condensate. After the condensate is heated, it enters the regenerator and then flows out of the regenerator. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage module.

[0024] (2) Off-peak electricity load period:

[0025] The condenser and circulating water pump are operating normally. The second and third valves are opened, the first valve is closed, and the power switch is closed. No high-temperature water flows through the indirect heat exchanger. The electrothermal conversion device is driven by the exhaust steam from the intermediate-pressure cylinder and / or the surplus power of the unit. The low-temperature water in the high-temperature heat storage module enters the electrothermal conversion device, is heated, and then returns to the high-temperature heat storage module. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the first-stage regenerative heater.

[0026] Preferably, when the method also includes a low-temperature heat storage module and a cooling tower, the operation method further includes the following steps:

[0027] (1) Peak electricity load period:

[0028] Close the cooling tower circulating water pump, the fourth valve, the fifth valve and the sixth valve, and open the seventh valve and the eighth valve. The low-temperature water in the low-temperature heat storage module enters the condenser. After being heated in the condenser, the low-temperature water returns to the low-temperature heat storage module.

[0029] (2) Off-peak electricity load period:

[0030] Turn on the cooling tower circulating water pump, the fourth valve, the fifth valve, and the sixth valve, and close the seventh valve and the eighth valve. The high-temperature water in the low-temperature heat storage module enters the electrothermal conversion device as a low-temperature heat source for heat exchange and cooling, and then returns to the low-temperature heat storage module. At the same time, the circulating cooling water at the bottom of the cooling tower enters the condenser for heat exchange and then returns to the cooling tower via the cooling tower circulating water pump.

[0031] Thirdly, another generator set flexibility adjustment device provided by the present invention includes a steam-water heat exchanger, a regenerative heater, a partitioned heat exchanger, a high-temperature heat storage module, an electrothermal conversion device, and an air-cooled island.

[0032] The steam inlet of the steam-water heat exchanger is connected to the low-pressure cylinder exhaust pipe via a ninth valve. The condensate outlet of the steam-water heat exchanger is connected in series with at least one stage of the regenerative heater via a condensate pump. The steam inlet of each stage of the regenerative heater is connected to the corresponding low-pressure cylinder stage extraction steam pipe. The low-temperature side of the indirect heat exchanger is connected in series on the condensate header between the steam-water heat exchanger and the final stage of the regenerative heater. The high-temperature side outlet of the high-temperature heat storage module is connected to the high-temperature side inlet of the indirect heat exchanger, and the low-temperature side inlet and outlet of the high-temperature heat storage module are connected to the indirect heat exchanger. The heat exchanger is connected to the high-temperature side outlet, and a first valve is installed on the connecting pipe between the two; the high-temperature side heat absorption end of the electrothermal conversion device is connected to the high-temperature side inlet and the low-temperature side inlet and outlet of the high-temperature heat storage module, and a second valve is installed on the connecting pipe between the two; the air-cooled island has two installation positions: the first installation position is that the air-cooled island is connected in series between the low-pressure cylinder exhaust pipe and the condensate header pipe upstream of the partition wall heat exchanger through the tenth valve; the second installation position is that the air-cooled island is connected in series between the steam-water heat exchanger and the partition wall heat exchanger.

[0033] The heat source input terminal of the electrothermal conversion device includes a steam interface, a condensate interface and an electrical interface. The steam interface is connected to the intermediate pressure cylinder exhaust pipe through a third valve. The condensate interface is connected to the condensate header pipe downstream of the primary regenerative heater. The electrical interface is connected to the unit motor through an electrical switch.

[0034] Preferably, the generator set flexibility adjustment device further includes a low-temperature heat storage module. The low-temperature heat release end of the electrothermal conversion device is connected to the high-temperature inlet and outlet and the low-temperature inlet of the low-temperature heat storage module, and a fourth valve is provided on the connecting pipe between the two. At the same time, the cooling water outlet of the steam-water heat exchanger is connected to the high-temperature inlet and outlet of the low-temperature heat storage module through an eleventh valve, and the cooling water inlet of the steam-water heat exchanger is connected to the low-temperature outlet of the low-temperature heat storage module through a twelfth valve.

[0035] Fourthly, the present invention provides an operating method for a generator set flexibility adjustment device as described in the third aspect, wherein when the air-cooled island is in the first installation position, the operating method includes:

[0036] (1) Peak electricity load period:

[0037] The steam-water heat exchanger and condensate pump are operating normally. Close the second, fourth, third, and tenth valves, open the ninth valve, disconnect the power switch, and the electrothermal conversion device and air-cooled island stop operating. The exhaust steam from the low-pressure cylinder enters the steam-water heat exchanger and condenses. The condensate exits from the steam-water heat exchanger and enters the indirect heat exchanger.

[0038] Opening the first, eleventh, and twelfth valves allows high-temperature water from the high-temperature heat storage module to enter the indirect heat exchanger to heat the condensate. After being heated, the condensate enters the regenerator and then flows out of the regenerator. After the high-temperature water cools down through heat exchange, it returns to the high-temperature heat storage module. Similarly, low-temperature water from the low-temperature heat storage module enters the steam-water heat exchanger, where it is heated before returning to the low-temperature heat storage module.

[0039] (2) Off-peak electricity periods:

[0040] When the air-cooled island is operating normally, the steam-water heat exchanger and condensate pump stop operating, the ninth valve is closed, the tenth valve is opened, the exhaust steam from the low-pressure cylinder enters the air-cooled island to condense, and the condensate flows out of the air-cooled island and into the indirect heat exchanger, and then flows out after passing through each stage of regenerating heaters.

[0041] Close the first, eleventh, and twelfth valves, open the second, fourth, and third valves, close the power switch, and use the exhaust steam from the intermediate-pressure cylinder and / or the unit's surplus power to drive the electrothermal conversion device. The low-temperature water in the high-temperature heat storage module enters the electrothermal conversion device, is heated, and then returns to the high-temperature heat storage module. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the regenerator. The high-temperature water in the low-temperature heat storage module, as a low-temperature heat source, enters the electrothermal conversion device for heat exchange and cooling before returning to the low-temperature heat storage module.

[0042] Fourthly, the present invention provides an operating method for a generator set flexibility adjustment device as described in the third aspect, wherein when the air-cooled island is in the second installation position, the operating method includes:

[0043] (1) Peak electricity load period:

[0044] The steam-water heat exchanger, air-cooled island, and condensate pump are operating normally. The second, fourth, and third valves are closed, the power switch is turned off, the electrothermal conversion device stops operating, the exhaust steam from the low-pressure cylinder enters the steam-water heat exchanger and condenses, and the condensate flows out of the steam-water heat exchanger and enters the indirect heat exchanger through the air-cooled island.

[0045] Opening the first, eleventh, and twelfth valves allows high-temperature water from the high-temperature heat storage module to enter the indirect heat exchanger to heat the condensate. After being heated, the condensate enters the regenerator and then flows out of the regenerator. After the high-temperature water cools down through heat exchange, it returns to the high-temperature heat storage module. Similarly, low-temperature water from the low-temperature heat storage module enters the steam-water heat exchanger, where it is heated before returning to the low-temperature heat storage module.

[0046] (2) Off-peak electricity load period:

[0047] The air-cooled island and condensate pump are operating normally, the steam-water heat exchanger is stopped, the exhaust steam from the low-pressure cylinder enters the air-cooled island after passing through the steam-water heat exchanger and condenses, the condensate enters the indirect heat exchanger, and then flows out after passing through each stage of regenerating heaters.

[0048] Close the first, eleventh, and twelfth valves, open the second, fourth, and third valves, close the power switch, and use the exhaust steam from the intermediate-pressure cylinder and / or the unit's surplus power to drive the electrothermal conversion device. The low-temperature water in the high-temperature heat storage module enters the electrothermal conversion device, is heated, and then returns to the high-temperature heat storage module. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the regenerator. The high-temperature water in the low-temperature heat storage module, as a low-temperature heat source, enters the electrothermal conversion device for heat exchange and cooling before returning to the low-temperature heat storage module.

[0049] The present invention has the following advantages due to the adoption of the above technical solutions:

[0050] 1. This invention utilizes low-temperature water (e.g., ice water) in a low-temperature heat storage tank to replace the circulating cooling water in the cooling tower and the cooling air in the air-cooled island, thereby reducing the back pressure of the unit and overcoming the limitation of the unit's back pressure by external environmental parameters, thus improving the unit's power generation capacity when power demand is high. At the same time, the waste heat recovery capacity of the ice water is extremely strong, and the waste heat of the exhaust steam during peak power periods is completely recovered by the ice water, improving the energy utilization efficiency of the power plant.

[0051] 2. This invention utilizes high-temperature water in a high-temperature heat storage tank to replace part of the regenerative extraction steam to heat the condensate, allowing the saved regenerative extraction steam to enter the steam turbine to generate electricity, thereby improving the unit's power generation capacity during peak electricity demand and reducing the unit's steam consumption rate.

[0052] 3. This invention uses steam with the ability to perform work during periods of low electricity demand and surplus off-peak electricity or other surplus electricity as a heating source or driving force for a heat pump. This further reduces the unit output during periods of low electricity load and increases the unit's peak-shaving capacity. At the same time, it converts the waste heat of exhaust steam in the low-temperature heat storage tank into high-temperature heat storage in the high-temperature tank, and produces high-temperature water while simultaneously producing ice water, enabling the solution of this invention to operate in a continuous cycle.

[0053] 4. This invention utilizes high-temperature thermal storage tanks, low-temperature thermal storage tanks, and heat pumps to transfer electricity from off-peak periods to peak periods, thereby improving the economic efficiency of power plant generation.

[0054] 5. This invention is applicable to the flexible regulation of thermal power plants that use nuclear energy, coal, gas, etc. as energy sources. Attached Figure Description

[0055] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0056] Figure 1 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment 1 of the present invention;

[0057] Figure 2 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment 2 of the present invention;

[0058] Figure 3 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment 3 of the present invention;

[0059] Figure 4 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment 4 of the present invention;

[0060] Figure 5 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment 5 of the present invention;

[0061] Figure 6 This is a schematic diagram of the generator set flexibility adjustment device provided in Embodiment Six of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0063] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., used to define components are merely for the convenience of distinguishing the aforementioned components. Unless otherwise stated, these terms have no special meaning and should not be construed as indicating or implying relative importance.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] This invention provides a generator set flexibility adjustment device and its operating method. The device includes a condenser, a regenerative heater, a high-temperature heat storage tank, a partitioned heat exchanger, a low-temperature heat storage tank, an electrothermal conversion device, and a series of control valves. The operating method involves altering the flow paths of exhaust steam and condensate. During peak electricity demand, the low-temperature water in the low-temperature heat storage tank reduces the unit's back pressure, increasing power generation while simultaneously recovering waste heat. The high-temperature water in the high-temperature heat storage tank replaces the regenerative extraction steam to heat the condensate, allowing the regenerative extraction steam to enter the low-pressure cylinder and perform work, further increasing power generation. During off-peak electricity demand, the condenser and regenerative extraction steam operate normally, using a portion of the steam entering the low-pressure cylinder and the unit's surplus electricity as driving force to produce high-temperature and low-temperature water, while simultaneously reducing the unit's output. This invention allows the unit to exceed its output limit during peak electricity demand and further reduce load during off-peak electricity demand, enabling wide-range adjustment of the generator set's output while recovering waste heat and improving energy utilization efficiency.

[0066] The generator set flexibility adjustment device and its operation method provided in the embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0067] Example 1:

[0068] Please see Figure 1 The generator set flexibility adjustment device provided in this embodiment includes a condenser 1, a condensate pump 2, a regenerative heater 3, a partition heat exchanger 4, a high-temperature heat storage tank 5, an electrothermal conversion device 6, a low-temperature heat storage tank 7, and a cooling tower 8.

[0069] Both the high-temperature heat storage tank 5 and the low-temperature heat storage tank 7 are water storage containers or pools. The steam inlet of the condenser 1 is connected to the exhaust pipe of the low-pressure cylinder (LP), and the condensate outlet of the condenser 1 is connected in series with at least one stage of regenerative heater 3 via a condensate pump 2. The steam inlets of each stage of the regenerative heater 3 are connected to the corresponding low-pressure cylinder stage extraction steam pipe. The low-temperature side of the indirect heat exchanger 4 is connected in series on the condensate header between the condenser 1 and the final stage regenerative heater 3. The high-temperature side outlet of the high-temperature heat storage tank 5 is connected to the high-temperature side inlet of the indirect heat exchanger 4, and the low-temperature side inlet and outlet of the high-temperature heat storage tank 5 are connected to the high-temperature side outlet of the indirect heat exchanger 4. A valve 9 is installed on the connecting pipe between the two. The high-temperature heat absorption end of the electrothermal conversion device 6 is connected to the high-temperature inlet and low-temperature inlet / outlet of the high-temperature heat storage tank 5, and a valve 10 is installed on the connecting pipe between them. The low-temperature heat release end of the electrothermal conversion device 6 is connected to the high-temperature inlet / outlet and low-temperature inlet of the low-temperature heat storage tank 7, and a valve 12 is installed on the connecting pipe between them. The cooling tower 8 is connected to the condenser 1 through the cooling tower circulating water pump 11 to form a circulation loop, and valves 13 and 14 are installed on the connecting pipe between them. At the same time, the outlet of the condenser 1 is also connected to the high-temperature inlet / outlet of the low-temperature heat storage tank 7, and the inlet of the condenser 1 is also connected to the low-temperature outlet of the low-temperature heat storage tank 7, and valves 15 and 16 are installed on the connecting pipe between them. The heat source input end of the electrothermal conversion device 6 includes a steam interface, a condensate interface, and an electrical interface. The steam interface is connected to the intermediate-pressure cylinder exhaust pipe through valve 17, the condensate interface is connected to the condensate header downstream of the first-stage regenerative heater, and the electrical interface is connected to the unit motor through power switch 18.

[0070] In the above embodiments, preferably, the electrothermal conversion device 6 can be one or more heating devices, whose heat source includes, but is not limited to, electricity during off-peak hours and / or turbine extraction steam, and whose low-temperature heat source includes, but is not limited to, waste heat from exhaust steam and / or air. Thus, the electrothermal conversion device 6 absorbs off-peak electricity, increasing the peak-shaving depth of the generator set, and simultaneously recovers waste heat from exhaust steam, improving energy utilization efficiency.

[0071] Based on the above-described generator set flexibility adjustment device, this embodiment also provides an operation method for the generator set flexibility adjustment device, including the following steps:

[0072] (1) Peak electricity load period:

[0073] Condenser 1 and condensate pump 2 are operating normally. Valves 10 and 17 are closed, power switch 18 is disconnected, electrothermal conversion device 6 stops operating, and condensate flows out of condenser 1 and into indirect heat exchanger 4.

[0074] Open valve 9, and the high-temperature water in the high-temperature heat storage tank 5 enters the indirect heat exchanger 4 to heat the condensate. After the condensate is heated and its temperature rises, it enters the regenerator 3 and then flows out of the regenerator 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5.

[0075] Shut down cooling tower circulating water pumps 11, 12, 13 and 14, and open valves 15 and 16. The chilled water in the low-temperature heat storage tank 7 enters the condenser 1. After being heated in the condenser 1, the chilled water returns to the low-temperature heat storage tank 7.

[0076] Through the above technical solution, the generator set flexibility adjustment device provided in this embodiment has the following advantages during peak power load periods:

[0077] Firstly, the purpose of setting up interstage regenerative extraction steam to heat condensate in steam turbines is to improve the unit's thermal efficiency, but it will reduce the unit's output. During peak power load periods, the steam turbine output should be increased as much as possible. Therefore, high-temperature water in the high-temperature heat storage tank is used to replace the interstage regenerative extraction steam in the steam turbine to heat the condensate, so that the originally designed regenerative extraction steam does work in the steam turbine to increase output instead of being extracted to heat condensate.

[0078] Secondly, by using low-temperature water from the low-temperature heat storage tank to replace the cooling circulating water in the cooling tower, the back pressure of the unit can be reduced, the enthalpy drop of steam can be increased, and thus the output of the steam turbine can be increased during peak power load periods.

[0079] (2) Off-peak electricity load period:

[0080] Condenser 1 and condensate pump 2 operate normally. Valves 10 and 17 are opened, valve 9 is closed, and power switch 18 is closed. No high-temperature water flows through the indirect heat exchanger 4. The electrothermal conversion device 6 is driven by the exhaust steam from the intermediate pressure cylinder and / or the surplus power of the unit. The low-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heating and then returns to the high-temperature heat storage tank 5. The condensate from the exhaust steam from the intermediate pressure cylinder after heat exchange enters the condensate header after the regenerator 3.

[0081] Turn on the cooling tower circulating water pump 11, valve 12, valve 13 and valve 14, and close valve 15 and valve 16. The water (high temperature water) that has absorbed the waste heat of the exhaust steam in the low temperature heat storage tank 7 enters the electrothermal conversion device 6 for heat exchange and cooling, and then returns to the low temperature heat storage tank 7. At the same time, the circulating cooling water at the bottom of the cooling tower 8 enters the condenser 1 for heat exchange and then returns to the cooling tower 8 via the cooling tower circulating water pump 11.

[0082] Through the above technical solution, the generator set flexibility adjustment device provided in this embodiment has the following advantages during periods of low power load:

[0083] Firstly, during periods of low electricity load, the turbine load should be as low as possible. Therefore, the steam and electricity generated by the turbine are used as driving energy to recover the waste heat from the exhaust steam during peak electricity load periods, so that the unit output and grid-connected electricity are minimized, thus achieving the goal of deep peak regulation.

[0084] Secondly, the high-temperature water in the high-temperature heat storage tank replaces the regenerative extraction steam to heat the condensate and release heat during peak power load periods, while the low-temperature water in the low-temperature heat storage tank replaces the cooling circulating water to absorb the heat from the exhaust steam during peak power load periods. By utilizing the turbine steam and power generation during off-peak power load periods as heat sources and driving forces, the waste heat from the exhaust steam in the low-temperature heat storage tank is recovered and stored in the high-temperature heat storage tank, which reduces the unit output and enables the system to operate in a cyclical manner.

[0085] Example 2:

[0086] Please see Figure 2 The difference between the generator set flexibility adjustment device provided in this embodiment and that in embodiment one is that the low-temperature side of the indirect heat exchanger 4 is connected in parallel to the condensate header between the condenser 1 and the final stage regenerative heater 3.

[0087] Based on the above-described generator set flexibility adjustment device, this embodiment also provides an operation method for the generator set flexibility adjustment device, including the following steps:

[0088] (1) Peak electricity load period:

[0089] Condenser 1 and condensate pump 2 are running normally. Valves 10 and 17 are closed, power switch 18 is turned off, electrothermal conversion device 6 stops operating, and condensate flows out of condenser 1 and enters the indirect heat exchanger 4 connected in parallel to the condensate header.

[0090] Open valve 9, and the high-temperature water in the high-temperature heat storage tank 5 enters the indirect heat exchanger 4 to heat the condensate. After the condensate is heated and its temperature rises, it enters the regenerator 3 and then flows out of the regenerator 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5.

[0091] Shut down cooling tower circulating water pumps 11, 12, 13 and 14, and open valves 15 and 16. The chilled water in the low-temperature heat storage tank 7 enters the condenser 1. After being heated in the condenser 1, the chilled water returns to the low-temperature heat storage tank 7.

[0092] (2) Off-peak electricity load period:

[0093] Condenser 1 and condensate pump 2 are operating normally. Valve 9 is closed. No high-temperature water flows through the indirect heat exchanger 4. After the condensate comes out of condenser 1, it flows directly through the regenerators 3 of each stage via the condensate header, without passing through the indirect heat exchanger 4.

[0094] Open valves 10 and 17, close power switch 18, and use the medium-pressure cylinder exhaust steam during the low power load period and the unit's surplus power (including but not limited to electricity and turbine extraction steam) to drive the electrothermal conversion device 6 to operate. The low-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heat exchange and temperature increase, and then returns to the high-temperature heat storage tank 5.

[0095] Turn on the cooling tower circulating water pump 11, valve 12, valve 13 and valve 14, and close valve 15 and valve 16. The high temperature water in the low temperature heat storage tank 7 enters the electrothermal conversion device 6, and returns to the low temperature heat storage tank 7 after heat exchange and cooling. At the same time, the circulating cooling water at the bottom of the cooling tower 8 enters the condenser 1 for heat exchange and then returns to the cooling tower 8 via the cooling tower circulating water pump 11.

[0096] Example 3:

[0097] Please see Figure 3 The difference between the generator set flexibility adjustment device provided in this embodiment and that in embodiment two is that the low-temperature side of the indirect heat exchanger 4 is connected in parallel with part of the regenerative heater 3.

[0098] Based on the above-described generator set flexibility adjustment device, this embodiment also provides an operation method for the generator set flexibility adjustment device, including the following steps:

[0099] (1) Peak electricity load period:

[0100] Condenser 1 and condensate pump 2 are running normally. Valves 10 and 17 are closed, power switch 18 is turned off, electrothermal conversion device 6 stops operating, and condensate flows out of condenser 1 and enters the indirect heat exchanger 4 connected in parallel to the condensate header.

[0101] When valve 9 is opened, the high-temperature water in the high-temperature heat storage tank 5 enters the partition heat exchanger 4 to heat the condensate. After the condensate is heated, it enters the downstream part of the regenerator 3 at the parallel connection of the partition heat exchanger 4, and then flows out of the regenerator 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5.

[0102] Shut down cooling tower circulating water pumps 11, 12, 13 and 14, and open valves 15 and 16. The chilled water in the low-temperature heat storage tank 7 enters the condenser 1. After being heated in the condenser 1, the chilled water returns to the low-temperature heat storage tank 7.

[0103] (2) Off-peak electricity load period:

[0104] Condenser 1 and condensate pump 2 are operating normally, valve 9 is closed, no high-temperature water flows through the indirect heat exchanger 4, and after the condensate comes out of condenser 1, it flows directly through the regenerators 3 of each stage via the condensate header without passing through the indirect heat exchanger 4.

[0105] Open valves 10 and 17, close power switch 18, and use the exhaust steam from the intermediate pressure cylinder and the surplus power of the unit to drive the electrothermal conversion device 6 to run. The high-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heating and then returns to the high-temperature heat storage tank 5. The condensate from the exhaust steam from the intermediate pressure cylinder after heat exchange enters the condensate header pipe after the regenerator 3.

[0106] Turn on the cooling tower circulating water pump 11, valve 12, valve 13 and valve 14, and close valve 15 and valve 16. The high temperature water in the low temperature heat storage tank 7 enters the electrothermal conversion device 6, and returns to the low temperature heat storage tank 7 after heat exchange and cooling. At the same time, the circulating cooling water at the bottom of the cooling tower 8 enters the condenser 1 for heat exchange and then returns to the cooling tower 8 via the cooling tower circulating water pump 11.

[0107] Example 4:

[0108] Please see Figure 4 The difference between the generator set flexibility adjustment device provided in this embodiment and that in embodiment three is that the low-temperature side of the indirect heat exchanger 4 is connected in parallel with all the regenerative heaters 3.

[0109] Based on the above-mentioned generator set flexibility adjustment device, the present invention also provides an operating method of the generator set flexibility adjustment device, comprising the following steps:

[0110] (1) Peak electricity load period:

[0111] Condenser 1 and condensate pump 2 are running normally. Valves 10 and 17 are closed, power switch 18 is turned off, electrothermal conversion device 6 stops operating, and condensate flows out of condenser 1 and enters the indirect heat exchanger 4 connected in parallel to the condensate header.

[0112] Open valve 9, and the high-temperature water in the high-temperature heat storage tank 5 enters the partition heat exchanger 4 to heat the condensate. After the condensate is heated and its temperature rises, it flows directly into the condensate header downstream of the primary regenerative heater 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5.

[0113] Shut down cooling tower circulating water pumps 11, 12, 13 and 14, and open valves 15 and 16. The chilled water in the low-temperature heat storage tank 7 enters the condenser 1. After being heated in the condenser 1, the chilled water returns to the low-temperature heat storage tank 7.

[0114] (2) Off-peak electricity load period:

[0115] Condenser 1 and condensate pump 2 are operating normally, valve 9 is closed, no high-temperature water flows through the indirect heat exchanger 4, and after the condensate comes out of condenser 1, it flows directly through the regenerators 3 of each stage via the condensate header without passing through the indirect heat exchanger 4.

[0116] Open valves 10 and 17, close power switch 18, and use the exhaust steam from the intermediate pressure cylinder and the surplus power of the unit to drive the electrothermal conversion device 6 to run. The high-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heating and then returns to the high-temperature heat storage tank 5. The condensate from the exhaust steam from the intermediate pressure cylinder after heat exchange enters the condensate header pipe after the regenerator 3.

[0117] Turn on the cooling tower circulating water pump 11, valve 12, valve 13 and valve 14, and close valve 15 and valve 16. The high temperature water in the low temperature heat storage tank 7 enters the electrothermal conversion device 6, and returns to the low temperature heat storage tank 7 after heat exchange and cooling. At the same time, the circulating cooling water at the bottom of the cooling tower 8 enters the condenser 1 for heat exchange and then returns to the cooling tower 8 via the cooling tower circulating water pump 11.

[0118] Example 5:

[0119] Please see Figure 5 The generator set flexibility adjustment device provided in this embodiment includes a steam-water heat exchanger 21, a regenerative heater 3, a partitioned heat exchanger 4, a high-temperature heat storage tank 5, an electrothermal conversion device 6, a low-temperature heat storage tank 7, and an air-cooled island 19.

[0120] Both the high-temperature heat storage tank 5 and the low-temperature heat storage tank 7 are water storage containers or pools. The steam inlet of the steam-water heat exchanger 21 is connected to the low-pressure cylinder exhaust pipe via valve 22, and the condensate outlet of the steam-water heat exchanger 21 is connected in series with at least one stage of regenerative heater 3 via condensate pump 2. The steam inlets of each stage of regenerative heater 3 are connected to the corresponding low-pressure cylinder stage extraction steam pipe. The low-temperature side of the indirect heat exchanger 4 is connected in series on the condensate header between the steam-water heat exchanger 21 and the final stage regenerative heater 3. The high-temperature side outlet of the high-temperature heat storage tank 5 is connected to the high-temperature side inlet of the indirect heat exchanger 4, and the low-temperature side inlet and outlet of the high-temperature heat storage tank 5 are connected to the high-temperature side outlet of the indirect heat exchanger 4. A first valve 9 is installed on the connecting pipe between the two. The high-temperature heat absorption end of the electrothermal conversion device 6 is connected to the high-temperature inlet and low-temperature inlet / outlet of the high-temperature heat storage tank 5, and a valve 10 is installed on the connecting pipe between them; the low-temperature heat release end of the electrothermal conversion device 6 is connected to the high-temperature inlet / outlet and low-temperature inlet of the low-temperature heat storage tank 7, and a valve 12 is installed on the connecting pipe between them. Simultaneously, the cooling water outlet of the steam-water heat exchanger 21 is connected to the high-temperature inlet / outlet of the low-temperature heat storage tank 7 via valve 23, and the cooling water inlet of the steam-water heat exchanger 21 is connected to the low-temperature outlet of the low-temperature heat storage tank 7 via valve 24. The air-cooled island 19 is connected in series between the low-pressure cylinder exhaust pipe and the condensate header upstream of the partition wall heat exchanger 4 via valve 20. The heat source input end of the electrothermal conversion device 6 includes a steam interface, a condensate interface, and an electrical interface. The steam interface is connected to the intermediate-pressure cylinder exhaust pipe via valve 17, the condensate interface is connected to the condensate header downstream of the primary regenerative heater, and the electrical interface is connected to the unit motor via power switch 18.

[0121] Based on the above-described generator set flexibility adjustment device, this embodiment also provides an operation method for the generator set flexibility adjustment device, including the following steps:

[0122] (1) Peak electricity load period:

[0123] When the steam-water heat exchanger 21 and the condensate pump 2 are operating normally, close valves 10, 12, 17 and 20, open valve 22, disconnect the power switch 18, the electrothermal conversion device 6 and the air-cooled island 19 stop operating, the exhaust steam from the low-pressure cylinder enters the steam-water heat exchanger 21 and condenses, and the condensate comes out of the steam-water heat exchanger 21 and enters the indirect heat exchanger 4.

[0124] When valves 9, 23, and 24 are opened, the high-temperature water in the high-temperature heat storage tank 5 enters the partition heat exchanger 4 to heat the condensate. After the condensate is heated, it enters the regenerator 3 and then flows out of the regenerator 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5. The ice water in the low-temperature heat storage tank 7 enters the steam-water heat exchanger 21. After the ice water is heated in the steam-water heat exchanger 21, it returns to the low-temperature heat storage tank 7.

[0125] (2) Off-peak electricity periods:

[0126] When the air-cooled island 19 is operating normally, the steam-water heat exchanger 21 and the condensate pump 2 stop operating, valve 22 is closed, valve 20 is opened, the exhaust steam from the low-pressure cylinder enters the air-cooled island 19 and condenses, and the condensate flows out of the air-cooled island 19 and enters the indirect heat exchanger 4, and then flows through the regenerators 3 at each stage before flowing out.

[0127] Close valves 9, 23, and 24, open valves 10, 12, and 17, and close power switch 18. Use the exhaust steam from the intermediate-pressure cylinder and / or the surplus power of the unit to drive the electrothermal conversion device 6. The low-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heating and then returns to the high-temperature heat storage tank 5. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the regenerator 3. The high-temperature water in the low-temperature heat storage tank 7, as a low-temperature heat source, enters the electrothermal conversion device 6 for heat exchange and cooling, and then returns to the low-temperature heat storage tank 7.

[0128] Example 6:

[0129] Please see Figure 6 The difference between the generator set flexibility adjustment device provided in this embodiment and that in embodiment five is that the air-cooled island 19 is connected in series between the steam-water heat exchanger 21 and the partition wall heat exchanger 4.

[0130] Based on the above-described generator set flexibility adjustment device, this embodiment also provides an operation method for the generator set flexibility adjustment device, including the following steps:

[0131] (1) Peak electricity load period:

[0132] When the steam-water heat exchanger 21, the air-cooled island 19 and the condensate pump 2 are operating normally, valves 10, 12 and 17 are closed, the power switch 18 is turned off, the electrothermal conversion device 6 stops operating, the exhaust steam from the low-pressure cylinder enters the steam-water heat exchanger 21 and condenses, and the condensate comes out of the steam-water heat exchanger 21 and enters the indirect heat exchanger 4 through the air-cooled island 19;

[0133] When valves 9, 23, and 24 are opened, the high-temperature water in the high-temperature heat storage tank 5 enters the partition heat exchanger 4 to heat the condensate. After the condensate is heated, it enters the regenerator 3 and then flows out of the regenerator 3. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage tank 5. The ice water in the low-temperature heat storage tank 7 enters the steam-water heat exchanger 21. After the ice water is heated in the steam-water heat exchanger 21, it returns to the low-temperature heat storage tank 7.

[0134] (2) Off-peak electricity load period:

[0135] Air-cooled island 19 and condensate pump 2 are operating normally, steam-water heat exchanger 21 is stopped, low-pressure cylinder exhaust steam enters air-cooled island 19 after passing through steam-water heat exchanger 21 and condenses, condensate enters indirect heat exchanger 4, and then flows through each stage of regenerator 3 before flowing out.

[0136] Close valves 9, 23, and 24, open valves 10, 12, and 17, and close power switch 18. Use the exhaust steam from the intermediate-pressure cylinder and / or the surplus power of the unit to drive the electrothermal conversion device 6. The low-temperature water in the high-temperature heat storage tank 5 enters the electrothermal conversion device 6 for heating and then returns to the high-temperature heat storage tank 5. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the regenerator 3. The high-temperature water in the low-temperature heat storage tank 7, as a low-temperature heat source, enters the electrothermal conversion device 6 for heat exchange and cooling, and then returns to the low-temperature heat storage tank 7.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A genset flexibility regulating device, characterized by, This includes condensers, regenerative heaters, indirect heat exchangers, high-temperature heat storage modules, and electrothermal conversion devices; The condenser's steam inlet is connected to the low-pressure cylinder exhaust pipe. The condenser is connected in series with at least one stage of the regenerative heater via a condensate pump. The steam inlets of each stage of the regenerative heater are connected to the corresponding low-pressure cylinder interstage extraction steam pipe. The indirect heat exchanger has four installation positions: the first installation position is that the low-temperature side of the indirect heat exchanger is connected in series on the condensate header between the condenser and the final stage regenerative heater; the second installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel on the condensate header between the condenser and the final stage regenerative heater; the third installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel with a portion of the regenerative heaters; and the fourth installation position is that the low-temperature side of the indirect heat exchanger is connected in parallel with all of the regenerative heaters. The high-temperature side outlet of the high-temperature heat storage module is connected to the high-temperature side inlet of the partition wall heat exchanger, and the low-temperature side inlet and outlet of the high-temperature heat storage module are connected to the high-temperature side outlet of the partition wall heat exchanger. A first valve is provided on the connecting pipe between the two. The high-temperature side heat absorption end of the electrothermal conversion device is connected to the high-temperature side inlet and the low-temperature side inlet and outlet of the high-temperature heat storage module. A second valve is provided on the connecting pipe between the two. The heat source input end of the electrothermal conversion device includes a steam interface, a condensate interface and an electrical interface. The steam interface is connected to the intermediate pressure cylinder exhaust pipe through a third valve. The condensate interface is connected to the condensate header pipe downstream of the primary regenerative heater. The electrical interface is connected to the unit motor through an electrical switch. It also includes a low-temperature heat storage module, wherein the low-temperature heat release end of the electrothermal conversion device is connected to the high-temperature inlet and outlet and the low-temperature inlet of the low-temperature heat storage module, and a fourth valve is provided on the connecting pipe between the two; the outlet of the condenser is also connected to the high-temperature inlet and outlet of the low-temperature heat storage module, and the inlet of the condenser is also connected to the low-temperature outlet of the low-temperature heat storage module, and a seventh valve and an eighth valve are provided on the connecting pipe between the two.

2. The generator set flexibility adjustment device according to claim 1, characterized in that, When the indirect heat exchanger is in the first installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump, the low-temperature side outlet of the indirect heat exchanger is connected to the inlet pipe of the final stage regenerator, and the indirect heat exchanger is installed on the condensate header. When the indirect heat exchanger is in the second installation position, a separate pipe is drawn from the outlet pipe of the condensate pump and connected to the low-temperature side inlet of the indirect heat exchanger, and a separate pipe is drawn from the inlet pipe of the final stage regenerator and connected to the low-temperature side outlet of the indirect heat exchanger. When the indirect heat exchanger is in the third installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump or another pipe is led from the outlet pipe of the condensate pump to the low-temperature side inlet of the indirect heat exchanger, and the low-temperature side outlet of the indirect heat exchanger is connected to the condensate mother channel of a certain intermediate stage of the regenerating heater. When the indirect heat exchanger is in the fourth installation position, the low-temperature side inlet of the indirect heat exchanger is connected to the outlet pipe of the condensate pump or another pipe is led from the outlet pipe of the condensate pump to the low-temperature side inlet of the indirect heat exchanger, and the low-temperature side outlet of the indirect heat exchanger is connected to the condensate main channel downstream of the primary regenerative heater.

3. The generator set flexibility adjustment device according to claim 2, characterized in that, It also includes a cooling tower, which is connected to the condenser via a cooling tower circulating water pump to form a circulation loop, and a fifth valve and a sixth valve are installed on the connecting pipe between the two.

4. The generator set flexibility adjustment device according to claim 1, characterized in that, The electric heating device is one or more heating devices, whose heat source comes from electricity during the off-peak period and / or steam extracted from the steam turbine, and whose low-temperature heat source comes from waste heat from exhaust steam and / or air.

5. A method for operating the generator set flexibility adjustment device as described in claim 3, characterized in that, include: (1) During peak electricity load periods: The condenser and condensate pump are operating normally. Close the second and third valves, disconnect the power switch, and the electrothermal conversion device stops operating. When the indirect heat exchanger is in the first or second installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. The condensate in the indirect heat exchanger is heated and then enters the final stage regenerative heater, and then flows out after passing through each stage of regenerative heater. When the indirect heat exchanger is in the third installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. After the condensate in the indirect heat exchanger is heated, it enters the regenerator of a certain stage from the condensate header of the intermediate regenerator, and then flows through the remaining regenerators before flowing out. When the indirect heat exchanger is in the fourth installation position, the condensate flows out of the condenser and enters the indirect heat exchanger through the condensate pump. After the condensate in the indirect heat exchanger is heated, it flows directly into the condensate header downstream of the primary regenerative heater. Open the first valve, and the high-temperature water in the high-temperature heat storage module enters the indirect heat exchanger to heat the condensate. After the condensate is heated, it enters the regenerator and then flows out of the regenerator. After the high-temperature water is cooled down by heat exchange, it returns to the high-temperature heat storage module. (2) Off-peak electricity load period: The condenser and circulating water pump are operating normally. The second and third valves are opened, the first valve is closed, and the power switch is closed. No high-temperature water flows through the indirect heat exchanger. The electrothermal conversion device is driven by the exhaust steam from the intermediate-pressure cylinder and / or the surplus power of the unit. The low-temperature water in the high-temperature heat storage module enters the electrothermal conversion device, is heated, and then returns to the high-temperature heat storage module. The condensate from the exhaust steam from the intermediate-pressure cylinder after heat exchange enters the condensate header after the first-stage regenerative heater.

6. The operating method according to claim 5, characterized in that, When the system also includes a low-temperature thermal storage module and a cooling tower, the operating method further includes the following steps: (1) Peak electricity load period: Close the cooling tower circulating water pump, the fourth valve, the fifth valve and the sixth valve, and open the seventh valve and the eighth valve. The low-temperature water in the low-temperature heat storage module enters the condenser. After being heated in the condenser, the low-temperature water returns to the low-temperature heat storage module. (2) Off-peak electricity load period: Turn on the cooling tower circulating water pump, the fourth valve, the fifth valve, and the sixth valve, and close the seventh valve and the eighth valve. The high-temperature water in the low-temperature heat storage module enters the electrothermal conversion device as a low-temperature heat source for heat exchange and cooling, and then returns to the low-temperature heat storage module. At the same time, the circulating cooling water at the bottom of the cooling tower enters the condenser for heat exchange and then returns to the cooling tower via the cooling tower circulating water pump.

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