High-temperature heat storage type power generation peak regulation and frequency modulation system

Abstract

The invention provides a high-temperature heat storage type power generation peak regulation and frequency modulation system, which relates to the technical field of thermoelectricity and comprises a power generation system, a first heat storage and heat exchange system and a second heat storage and heat exchange system, the power generation system comprises a generator, a water supply device, a steam generator, a superheater, a turbine and a condenser, the first heat storage and exchange system comprises a first electric heater, a first heat storage device, a first circulating fan and a first gas circulating pipeline; the second heat storage and exchange system comprises a second electric heater, a second heat storage device, a second circulating fan and a second gas circulating pipeline; rich electric energy can be converted into heat energy to be stored, when frequency modulation and peak regulation are needed, the stored heat energy is used for driving the steam turbine set to generate electricity, rotation inertia and primary frequency modulation capacity are provided for a power grid, and peak clipping and valley filling are achieved.

Description

Technical Field

[0001] The present invention relates to the field of thermoelectric technology, and in particular to a high-temperature heat storage type power generation peak regulation and frequency modulation system. Background Art

[0002] Large-scale grid connection of new energy sources such as wind power and photovoltaic power generation is an important path to achieve the "dual carbon" goal. The inherent intermittency and volatility of new energy sources will bring huge challenges to the real-time balance of the power grid, resulting in an increasing demand for peak and frequency regulation of the power grid, and higher requirements for the "quality" and "quantity" of the flexible regulation capacity of the power grid. Therefore, it is necessary to design a peak and frequency regulation system to provide primary frequency regulation capabilities for the power grid, better realize peak shaving and valley filling, and improve energy utilization. Summary of the invention

[0003] The purpose of the present invention is to provide a high-temperature heat storage type power generation peak-shaving and frequency regulation system to solve the problems existing in the prior art. It can convert surplus electrical energy into thermal energy for storage, and when frequency regulation and peak regulation are needed, the stored thermal energy can be used to drive the steam turbine unit to generate electricity, provide rotational inertia and primary frequency regulation capability for the power grid, and achieve peak shaving and valley filling.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A high-temperature heat storage type power generation peak-shaving and frequency modulation system, comprising a power generation system, a first heat storage and heat exchange system and a second heat storage and heat exchange system, the power generation system comprising a generator and a water supply device, a steam generator, a superheater, a steam turbine and a condenser connected in sequence; the power output end of the steam turbine is connected to the power input end of the generator, and the power output end of the generator is connected to a high-voltage power grid; the water supply device is used to supply water to the steam generator, the steam generator is used to generate saturated steam, the superheater is used to heat saturated steam into superheated steam, the steam turbine is used to use superheated steam to drive the generator to generate electricity, and the condenser is used to condense the steam discharged from the steam turbine; the first heat storage and heat exchange system comprises a first electric heater, a first heat storage device, a first circulation fan and a first gas circulation pipeline, the first an electric heater connected to the distribution network, the first electric heater is used to heat the first heat storage device; the first heat storage device, the first circulation fan and the steam generator are all arranged on the first gas circulation pipeline, and the gas in the first gas circulation pipeline is heated by the first heat storage device and then exchanges heat with the water in the steam generator; the second heat storage and heat exchange system comprises a second electric heater, a second heat storage device, a second circulation fan and a second gas circulation pipeline, the second electric heater is connected to the distribution network, and the second electric heater is used to heat the second heat storage device; the second heat storage device, the second circulation fan and the superheater are all arranged on the second gas circulation pipeline, and the gas in the second gas circulation pipeline is heated by the second heat storage device and then exchanges heat with the steam in the superheater.

[0006] As an embodiment, the first heat storage device and the second heat storage device are both made of heat storage materials, and the first heat storage device and the second heat storage device are both provided with heat extraction channels, and the heat extraction channels are connected to the first gas circulation pipeline or the second gas circulation pipeline.

[0007] As an embodiment, the first electric heater and the second electric heater are both electromagnetic induction heaters correspondingly arranged in the first heat storage device and the second heat storage device.

[0008] As an implementation manner, the first heat storage device and the second heat storage device are both made of iron.

[0009] As an embodiment, a desuperheater for controlling the inlet air temperature of the steam turbine is further provided between the superheater and the steam turbine.

[0010] As an embodiment, the water supply device includes a water tank for supplying water to the steam generator.

[0011] As an implementation manner, a water pump is provided at the drain outlet of the condenser, and a water outlet of the water pump is communicated with the steam generator and / or the water tank.

[0012] As an implementation mode, the generator is connected to the high voltage grid via a transformer.

[0013] As an implementation manner, the distribution network is connected to the first heat storage device and the second heat storage device through the electric heating temperature controller.

[0014] As an embodiment, the first gas circulation pipeline and the second gas circulation pipeline are both filled with inert gas.

[0015] Compared with the prior art, the present invention has the following technical effects:

[0016] The present invention can convert surplus electric energy into thermal energy and store it in the first heat storage device and the second heat storage device by setting a first heat storage heat exchange system and a second heat storage heat exchange system. When peak shaving and frequency regulation are needed, the thermal energy in the first heat storage device and the thermal energy in the second heat storage device are used to heat the subcooled water passed into the steam heat exchanger and the saturated steam passed into the superheater respectively, and finally the superheated steam is obtained to drive the steam turbine to do work and drive the generator to generate electricity, thereby providing rotational inertia and primary frequency regulation capability for the power grid, realizing peak shaving and valley filling. The present invention can be widely used in the fields of peak shaving and frequency regulation of power systems such as new energy stations and flexibility transformation of thermal power plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of a high-temperature thermal storage type power generation peak load regulation and frequency modulation system in one embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the structure of a first heat storage device and a second heat storage device in one embodiment of the present invention;

[0020] Description of reference numerals:

[0021] 1. Water tank; 2. Steam generator; 3. Superheater; 4. Desuperheater; 5. Steam turbine; 6. Generator; 7. Condenser; 8. First heat storage device; 9. Second heat storage device; 10. First circulation fan; 11. Second circulation fan; 12. Water pump; 13. Heat extraction channel; 14. Heat storage channel; 15. Electric heating temperature controller; 16. Transformer. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0023] The purpose of the present invention is to provide a high-temperature heat storage type power generation peak-shaving and frequency regulation system to solve the problems existing in the prior art. It can convert surplus electrical energy into thermal energy for storage, and when frequency regulation and peak regulation are needed, the stored thermal energy can be used to drive the steam turbine unit to generate electricity, provide rotational inertia and primary frequency regulation capability for the power grid, and achieve peak shaving and valley filling.

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, this embodiment provides a high-temperature heat storage power generation peak-shaving and frequency regulation system, including a power generation system, a first heat storage and heat exchange system, and a second heat storage and heat exchange system.

[0026] The main function of the power generation system is to complete the steam-water cycle and use steam to drive the steam turbine 5 to generate electricity and realize power generation and grid connection. Specifically, the power generation system includes a generator 6 and a water supply device, a steam generator 2, a superheater 3, a steam turbine 5 and a condenser 7 connected in sequence; the power output end of the steam turbine 5 is connected to the power input end of the generator 6, and the power output end of the generator 6 is connected to the high-voltage power grid; the water supply device is used to provide a stable water source to the steam generator 2 during the start-up time of the peak-shaving and frequency-modulating system. In order to ensure the water quality and water temperature, the water supply device includes a water quality treatment unit (such as a filter membrane device) and a temperature control unit (such as a water temperature controller). The filter membrane device and the water temperature controller are both commonly used devices in this field. The specific structures of the two are not repeated in this embodiment. The steam generator 2 is a saturated boiler used to convert superheated water into saturated steam. After the saturated steam flows into the superheater 3, it is further heated and becomes high-temperature and high-pressure superheated steam, which then flows into the steam turbine 5, driving the steam turbine 5 to work. While the steam turbine 5 works, it drives the generator 6 to generate electricity, and the electricity generated by the generator 6 is connected to the high-voltage power grid through the transformer 16. The steam exhausted by the steam turbine 5 enters the condenser 7. After passing through the condenser 7, the steam exhausted by the steam turbine 5 is completely condensed, and the condensed water can continue to be supplied to the steam generator 2 for use or used in other working conditions.

[0027] The first heat storage and heat exchange system and the second heat storage and heat exchange system are both used to convert surplus electric energy into heat energy for storage, and release the heat energy when the peak-shaving and frequency modulation system is running, driving the steam turbine 5 to generate electricity. Specifically, the first heat storage and heat exchange system includes a first electric heater, a first heat storage device 8, a first circulation fan 10 and a first gas circulation pipeline; wherein the first electric heater is connected to the power distribution network, and the first electric heater is used to heat the first heat storage device 8, and the first heat storage device 8 is used to store heat; the first heat storage device 8, the first circulation fan 10 and the steam generator 2 are all arranged on the first gas circulation pipeline, and when the gas in the first gas circulation pipeline flows through the first heat storage device 8, the heat in the first heat storage device 8 is obtained, and the gas after obtaining the heat exchanges heat with the supercooled water in the steam generator 2, and the supercooled water in the steam generator 2 is heated to saturated steam.

[0028] The second heat storage and heat exchange system includes a second electric heater, a second heat storage device 9, a second circulation fan 11 and a second gas circulation pipeline; wherein the second electric heater is connected to the power distribution network, and the second electric heater is used to heat the second heat storage device 9, and the second heat storage device 9 is used to store heat; the second heat storage device 9, the second circulation fan 11 and the steam generator 2 are all arranged on the second gas circulation pipeline, and when the gas in the second gas circulation pipeline flows through the second heat storage device 9, the heat in the second heat storage device 9 is obtained, and the gas after obtaining the heat exchanges heat with the saturated steam in the superheater 3, and the saturated steam is heated to superheated steam.

[0029] Therefore, this embodiment can convert surplus electric energy (such as excess electric energy generated at night) into heat energy and store it in the first heat storage device 8 and the second heat storage device 9 by setting the first heat storage heat exchange system and the second heat storage system. When peak load and frequency regulation are required (for example, when the electricity consumption is large during the day), the heat energy in the first heat storage device 8 and the heat energy in the second heat storage device 9 are used to heat the subcooled water passed into the steam heat exchanger and the saturated steam passed into the superheater 3 respectively, and finally the superheated steam is obtained to drive the steam turbine 5 to do work, and drive the generator 6 to generate electricity, so as to provide the power grid with rotational inertia and primary frequency regulation capability, realize peak load shaving and valley filling, and can be widely used in the fields of peak load and frequency regulation of power systems such as new energy stations and flexibility transformation of thermal power plants.

[0030] It should be noted that the heat required to heat supercooled water into saturated steam is greater than the heat required to heat saturated steam into superheated steam. Therefore, during the design phase, the heat storage capacity design of the first heat storage device 8, the selection of the first circulation fan 10, and the size of the first gas circulation pipeline all need to be reasonably selected according to the actual application environment.

[0031] As an implementation mode, the first heat storage heat exchange system and the second heat storage heat exchange system in this embodiment are basically the same except that the heat-taking gas heating objects are different. Among them, the first heat storage device 8 and the second heat storage device 9 are both made of heat storage materials. In this embodiment, the thermal conductivity of the heat storage materials of the first heat storage device 8 and the second heat storage device 9 is greater than 50W / (m·K). High thermal conductivity can enhance the heat transfer effect, accelerate the heat storage and heat release rate, shorten the start-up time of the steam turbine 5, and improve energy utilization. The high temperature resistance of the first heat storage device 8 and the second heat storage device 9 is not less than 800°C, and can provide industrial high-temperature steam of not less than 400°C to 500°C. Specifically, in this embodiment, the first heat storage device 8 and the second heat storage device 9 are both made of iron. In terms of structural setting, the first heat storage device 8 and the second heat storage device 9 are both provided with a heat extraction channel 13, such as Figure 2 As shown, the heat extraction channel 13 is connected to the first gas circulation pipeline or the second gas circulation pipeline. The heat extraction channel 13 is used to circulate the heat exchange gas so that the gas can obtain the heat stored in the first heat storage device 8 and the second heat storage device 9.

[0032] In this embodiment, the gases in the first gas circulation pipeline and the second gas circulation pipeline are both inert gases.

[0033] As an embodiment, the first electric heater and the second electric heater are electromagnetic induction heaters correspondingly arranged in the first heat storage device 8 and the second heat storage device 9. Specifically, the first heat storage device 8 and the second heat storage device 9 are both provided with a heat storage channel 14, such as Figure 2 As shown; the electromagnetic induction heater is embedded in the heat storage channel 14, and heats the first heat storage device 8 and the second heat storage device 9 by the principle of electromagnetic induction to store thermal energy.

[0034] As an embodiment, a desuperheater 4 for controlling the inlet temperature of the steam turbine 5 is further provided between the superheater 3 and the steam turbine 5 to ensure that the temperature of the superheated steam flowing into the steam turbine 5 meets the requirements.

[0035] As an embodiment, the water supply device includes a water tank 1 for supplying water to the steam generator 2. The water tank 1 is at a high position relative to the steam generator 2 and is used to replenish water to the steam generator 2. A water pump 12 is provided at the drain port of the condenser 7, and the water outlet of the water pump 12 is connected to the steam generator 2 and / or the water tank 1, and can discharge condensed water into the water tank 1 for storage, or directly pass the condensed water into the steam generator 2 for replenishing water.

[0036] As one embodiment, the distribution network is connected to the first heat storage device 8 and the second heat storage device 9 through an electric heating temperature controller 15, and the electric heating temperature controller 15 can control the output energy storage heating current according to the temperature feedback of the first heat storage device 8 and the second heat storage device 9.

[0037] Adaptive changes made according to actual needs are all within the protection scope of the present invention.

[0038] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high-temperature thermal storage power generation peak-shaving and frequency-modulating system, characterized in that: include: A power generation system, the power generation system comprising a generator and a water supply device, a steam generator, a superheater, a steam turbine and a condenser connected in sequence; the power output end of the steam turbine is connected to the power input end of the generator, and the power output end of the generator is connected to a high-voltage power grid; the water supply device is used to supply water to the steam generator, the steam generator is used to generate saturated steam, the superheater is used to heat the saturated steam into superheated steam, the steam turbine is used to use the superheated steam to drive the generator to generate electricity, and the condenser is used to condense the steam discharged from the steam turbine; a first heat storage and heat exchange system, the first heat storage and heat exchange system comprising a first electric heater, a first heat storage device, a first circulation fan and a first gas circulation pipeline, the first electric heater being connected to a power distribution network, the first electric heater being used to heat the first heat storage device; the first heat storage device, the first circulation fan and the steam generator being all arranged on the first gas circulation pipeline, the gas in the first gas circulation pipeline being heated by the first heat storage device and then exchanging heat with water in the steam generator; and a second heat storage and heat exchange system, wherein the second heat storage and heat exchange system comprises a second electric heater, a second heat storage device, a second circulation fan and a second gas circulation pipeline, wherein the second electric heater is connected to the distribution network and is used to heat the second heat storage device; the second heat storage device, the second circulation fan and the superheater are all arranged on the second gas circulation pipeline, and the gas in the second gas circulation pipeline is heated by the second heat storage device and then exchanges heat with the steam in the superheater.

2. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1 is characterized in that: The first heat storage device and the second heat storage device are both made of heat storage materials. The first heat storage device and the second heat storage device are both provided with heat extraction channels, and the heat extraction channels are connected to the first gas circulation pipeline or the second gas circulation pipeline.

3. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 2 is characterized in that: The first electric heater and the second electric heater are both electromagnetic induction heaters correspondingly arranged in the first heat storage device and the second heat storage device.

4. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 3 is characterized in that: The first heat storage device and the second heat storage device are both made of iron.

5. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1, characterized in that: A desuperheater for controlling the inlet air temperature of the steam turbine is also provided between the superheater and the steam turbine.

6. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1, characterized in that: The water supply device includes a water tank for supplying water to the steam generator.

7. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 6, characterized in that: A water pump is provided at the drain outlet of the condenser, and a water outlet of the water pump is communicated with the steam generator and / or the water tank.

8. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1, characterized in that: The generator is connected to the high voltage power grid via a transformer.

9. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1, characterized in that: The distribution network is connected to the first heat storage device and the second heat storage device through the electric heating temperature controller.

10. The high temperature thermal storage type power generation peak load regulation and frequency modulation system according to claim 1, characterized in that: The first gas circulation pipeline and the second gas circulation pipeline are both filled with inert gas.

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