Frequency modulation and peak regulation system for thermal power generating unit

Abstract

A frequency modulation and peak regulation system for a thermal power generating unit, comprising: a generator set, comprising a main steam turbine (1), a generator (2), a condenser (3), and a deaerator (4), wherein a steam exhaust port of the main steam turbine (1) is connected to an inlet of the condenser (3), and an outlet of the condenser (3) is connected to an inlet of the deaerator (4); and a frequency modulation and peak regulation unit, comprising a frequency modulation steam turbine (5), a clutch (6), a molten salt heat storage device (7), and an electric heater (8), wherein the frequency modulation steam turbine (5) is coaxial to the generator (2) by means of the clutch (6), a steam exhaust port of the frequency modulation steam turbine (5) is connected to the inlet of the condenser (3), the molten salt heat storage device (7) comprises a salt pool and a heat exchange channel (71), an inlet of the heat exchange channel (71) is connected to an outlet of the deaerator (4), an outlet of the heat exchange channel (71) is connected to a steam inlet of the frequency modulation steam turbine (5), and the electric heater (8) is connected to the generator (2) so as to heat the heat storage medium in the salt pool. According to the frequency modulation and peak regulation system for a thermal power generating unit, deep peak regulation and frequency modulation of the thermal power generating unit can be realized, the electric load ramp rate of the generator set is improved, and the variable load response rate of the generator set is improved.

Description

A frequency regulation and peak regulation system for thermal power generation units CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the priority of the Chinese patent application filed with the China Patent Office on October 7, 2023, with application number 202311287684.3 and invention name “A frequency and peak regulation system for thermal power units”, the entire contents of which are incorporated herein by reference. Technical Field The present application relates to the technical field of coal-fired power generation, and in particular to a frequency and peak regulation system for a thermal power unit. Background Art Generally, molten salt thermal storage technology is a new technology that uses high-temperature thermal energy to store energy and potential energy. During the storage stage, the power grid outputs electrical energy to the storage system, converts it into thermal energy, and stores it in molten salt; during the release process, the energy storage system converts heat into electrical energy and provides electricity. There are many ways to release heat in the coupling of molten salt heat storage devices and thermal power units. One is that when the molten salt device releases heat, condensate is introduced into the molten salt device, and the heated condensate returns to the condensate system of the generator set. The second is that when the molten salt device releases heat, condensate is introduced into the molten salt device, and steam is generated after heating and returns to the steam system. At present, the heated steam is mainly sent to the external network for heating or returned to the power plant steam system to be sent to the steam turbine for power generation. The invention of patent number 202310453336.2 discloses a power generation system and operation method of coupling molten salt heat storage with coal-fired units. The patent mentions that molten salt can be used to absorb the heat of flue gas in the vertical flue at the tail of the coal-fired boiler and the heat of low-temperature flue gas after denitrification, reduce the power generation output of the steam turbine generator set, and respond to the deep peak regulation of the power grid. In addition, after absorbing heat and heating, high-temperature and medium-temperature molten salts are stored separately, which can be used for peak power generation, rapid frequency regulation, industrial steam supply and centralized heating, and realize the efficient utilization of energy cascade. This technology has the disadvantages of complex system, large investment and large land area. This technology improves the deep peak regulation capability to a certain extent, but does not significantly help the unit climbing rate. Summary of the invention The present application aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the embodiment of the present application proposes a frequency and peak regulation system for a thermal power unit, which can realize deep peak regulation and frequency regulation of the thermal power unit, improve the load climbing rate of the generator unit, and improve the variable load response rate of the generator unit. The frequency and peak regulation system of a thermal power unit in the embodiment of the present application comprises: A generator set, the generator set comprising a main steam turbine, a generator, a condenser and a deaerator, the main steam turbine and the generator are coaxially arranged, the exhaust port of the main steam turbine is connected to the inlet of the condenser, and the outlet of the condenser is connected to the inlet of the deaerator; and A frequency-modulation and peak-shaving unit, the frequency-modulation and peak-shaving unit comprising a frequency-modulation steam turbine, a clutch, a molten salt heat storage device and an electric heater, the frequency-modulation steam turbine being coaxially arranged with the generator through the clutch, the exhaust port of the frequency-modulation steam turbine being connected to the inlet of the condenser, the molten salt heat storage device comprising a salt pool and a heat exchange channel, the inlet of the heat exchange channel being connected to the outlet of the deaerator, the outlet of the heat exchange channel being connected to the steam inlet of the frequency-modulation steam turbine, and the electric heater being connected to the generator so as to heat the heat storage medium in the salt pool. The frequency regulation and peak regulation system of the thermal power unit of the embodiment of the present application realizes energy storage through a molten salt heat storage device and an electric heater, assists the generator set to realize load increase and load decrease, and improves the peak regulation depth capability of the generator set; the heat release process of the molten salt heat storage device is coupled with the frequency regulation steam turbine, and the heat release of the molten salt heat storage device is used to drive the frequency regulation steam turbine to rotate, which can not only change the output power of the frequency regulation and peak regulation system of the thermal power unit, increase or decrease the electric load, and achieve the frequency regulation purpose of the generator set, but also improve the electric load climbing rate of the generator set and improve the variable load response rate of the generator set. In addition, the frequency regulation steam turbine is coaxially connected in series with the main steam turbine and the generator, that is, the power generation of the generator is equal to the power generation of the main steam turbine and the power generation of the frequency regulation steam turbine. When the purpose of unit frequency regulation is achieved, there is no need to add a new generator, which reduces the equipment investment and cost of the frequency regulation and peak regulation system of the thermal power unit. In some embodiments, the molten salt heat storage device further includes a molten salt pump, the inlet of the molten salt pump is connected to the bottom of the salt pool, the outlet of the molten salt pump is connected to the inlet of the electric heater to deliver the heat storage medium in the salt pool to the electric heater, and the outlet of the electric heater is connected to the top of the salt pool. In some embodiments, the frequency regulation and peak regulation system of the thermal power unit further comprises a transformer, the transformer is connected to the generator, the transformer is used to connect to the power grid to integrate electric energy into the power grid, a power branch is provided between the transformer and the generator, and the power branch is connected to the electric heater; The frequency-modulation and peak-shaving unit further includes a first switch, which is arranged on the power branch to control the on-off of the power branch. In some embodiments, the frequency-modulation and peak-shaving unit further includes a water feed pump and a first electric valve, the inlet of the water feed pump is connected to the outlet of the deaerator, the outlet of the water feed pump is connected to the inlet of the first electric valve, and the outlet of the first electric valve is connected to the inlet of the heat exchange channel. In some embodiments, the frequency-modulation and peak-shaving unit further includes a first regulating valve, an inlet of the first regulating valve is connected to an outlet of the first electric valve, and an outlet of the first regulating valve is connected to an inlet of the heat exchange channel. In some embodiments, the peak-shaving and frequency-regulating unit further includes a second electric valve, an inlet of the second electric valve is connected to an outlet of the heat exchange channel, and an outlet of the second electric valve is connected to a steam inlet of the frequency-regulating steam turbine. In some embodiments, the peak-shaving and frequency-regulating unit further includes a second regulating valve, the inlet of the second regulating valve is connected to the outlet of the second electric valve, and the outlet of the second regulating valve is connected to the steam inlet of the frequency-regulating steam turbine. In some embodiments, the generator set further includes a condensate pump and a third electric valve, the inlet of the condensate pump is connected to the outlet of the condenser, the outlet of the condensate pump is connected to the inlet of the third electric valve, and the outlet of the third electric valve is connected to the inlet of the deaerator. In some embodiments, the generator set further includes a third regulating valve, the inlet of the third regulating valve is connected to the third electric The outlet of the valve is connected to the inlet of the deaerator. BRIEF DESCRIPTION OF THE DRAWINGS FIG1 is a schematic diagram of a frequency and peak regulation system for a thermal power unit according to an embodiment of the present application. Reference numerals: Main steam turbine 1, generator 2, condenser 3, deaerator 4, frequency-modulated steam turbine 5, clutch 6, molten salt heat storage device 7, heat exchange Channel 71, molten salt pump 72, electric heater 8, transformer 9, first switch 11, power branch 10, water supply pump 12, first electric valve 13, first regulating valve 14, second electric valve 15, second regulating valve 16, condensate pump 17, third electric valve 18, third regulating valve 19. DETAILED DESCRIPTION The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application. As shown in Fig. 1, the frequency regulation and peak regulation system 100 of the thermal power unit of the embodiment of the present application includes a generator set and a frequency regulation and peak regulation unit. The generator set includes a main steam turbine 1, a generator 2, a condenser 3 and a deaerator 4. The main steam turbine 1 is coaxially arranged with the generator 2. The exhaust port of the main steam turbine 1 is connected to the inlet of the condenser 3, and the outlet of the condenser 3 is connected to the inlet of the deaerator 4. The frequency modulation and peak regulation unit includes a frequency modulation steam turbine 5, a clutch 6, a molten salt heat storage device 7 and an electric heater 8. The frequency modulation steam turbine 5 is coaxially arranged with the generator 2 through the clutch 6. The exhaust port of the frequency modulation steam turbine 5 is connected to the inlet of the condenser 3. The molten salt heat storage device 7 includes a salt pool and a heat exchange channel 71. The inlet of the heat exchange channel 71 is connected to the outlet of the deaerator 4, and the outlet of the heat exchange channel 71 is connected to the steam inlet of the frequency modulation steam turbine 5. The electric heater 8 is connected to the generator 2 to heat the heat storage medium in the salt pool. The operation mode of the frequency regulation and peak regulation system 100 of the thermal power unit in the embodiment of the present application is as follows: The frequency-modulation and peak-shaving unit assists the generator set in deep peak-shaving: the clutch 6 is disconnected, the frequency-modulation steam turbine 5 does not run, the connection between the outlet of the deaerator 4 and the inlet of the heat exchange channel 71 is disconnected, and when the generator set needs to reduce the load, the electric heater 8 is turned on to consume the electric energy output by the generator 2 to heat the heat storage medium of the molten salt heat storage device 7, thereby realizing heat storage and energy storage, reducing the power output by the frequency-modulation and peak-shaving system 100 of the thermal power unit, and achieving the purpose of deep peak-shaving capability. When the load needs to be increased: turn off the electric heater 8, connect the inlet of the heat exchange channel 71 and the outlet of the deaerator 4, use the heat energy stored in the heat storage medium of the molten salt heat storage device 7 to heat the water in the heat exchange channel 71, and the water vapor discharged from the heat exchange channel 71 enters the frequency-modulating steam turbine 5 to warm up the frequency-modulating steam turbine 5. When the speed of the frequency-modulating steam turbine 5 is consistent with the speed of the main steam turbine 1, close the clutch 4 to improve the heating efficiency of the water in the heat exchange channel 71 by the heat energy stored in the heat storage medium, thereby increasing the speed of the frequency-modulating steam turbine 5, thereby increasing the output power of the generator 2, and increasing the power output of the frequency-modulating peak-shaving system 100 of the thermal power unit. The frequency-modulating and peak-shaving unit assists the frequency modulation of the generator set: when the clutch 4 is closed, the electric heater 8 is turned on, and the inlet of the heat exchange channel 71 is connected to the outlet of the deaerator 4, when the load of the generator set is increased, the heating power of the electric heater 8 is reduced, and the heating power of the molten salt heat storage device 7 is increased. The heat exchange efficiency between the heat storage medium and the water in the heat exchange channel 71 increases the temperature and flow rate of the water vapor discharged from the heat exchange channel 71, thereby increasing the power of the frequency-modulated steam turbine 5, thereby quickly increasing the output power of the generator 2. When the generator set reduces the load, the heating power of the electric heater 8 is increased, the heat exchange efficiency between the heat storage medium of the molten salt heat storage device 7 and the water in the heat exchange channel 71 is reduced, the temperature and flow rate of the water vapor discharged from the heat exchange channel 71 are reduced, and the power of the frequency-modulated steam turbine 5 is reduced, thereby quickly reducing the output power of the generator 2. The frequency-modulated and peak-shaving unit of the embodiment of the present application assists the frequency modulation of the generator set to achieve the response rate of the frequency-modulated and peak-shaving system 100 of the thermal power unit when increasing and decreasing the load. The frequency regulation and peak regulation system 100 of the thermal power unit of the embodiment of the present application realizes energy storage through the molten salt heat storage device 7 and the electric heater 8, assists the generator set to realize load increase and load decrease, and improves the peak regulation depth capability of the generator set; the heat release process of the molten salt heat storage device 7 is coupled with the frequency regulation steam turbine 5, and the heat release of the molten salt heat storage device 7 is used to drive the frequency regulation steam turbine 5 to rotate, which can not only change the output power of the frequency regulation and peak regulation system 100 of the thermal power unit, increase or decrease the electric load, and achieve the frequency regulation purpose of the generator set, but also improve the electric load climbing rate of the generator set and improve the variable load response rate of the generator set. In addition, the frequency regulation steam turbine 5 is coaxially connected in series with the main steam turbine 1 and the generator 2, that is, the power generation of the generator 2 is equal to the power generation of the main steam turbine 1 and the power generation of the frequency regulation steam turbine 5. When the purpose of unit frequency regulation is achieved, there is no need to add a generator, which reduces the equipment investment and cost of the frequency regulation and peak regulation system 100 of the thermal power unit. In order to make the solution of the present application easier to understand, FIG1 is taken as an example for explanation. The frequency and peak regulation system 100 of the thermal power unit in the embodiment of the present application includes a generator set, a frequency and peak regulation unit and a transformer 9. The generator set includes a main steam turbine 1 , a generator 2 , a condenser 3 , a deaerator 4 , a condensate pump 17 , a third electric valve 18 and a third regulating valve 19 . The main steam turbine 1 is coaxially arranged with the generator 2, and the main steam turbine 1 is driven by the steam generated by the boiler of the generator set. The exhaust port of the main steam turbine 1 is connected to the inlet of the condenser 3, and the outlet of the condenser 3 is connected to the inlet of the deaerator 4. The main steam turbine 1 is coaxially arranged with the generator 2. The transformer 9 is connected to the generator 2, and the transformer 9 is used to connect to the power grid to integrate the electric energy into the power grid. The inlet of the condensate pump 17 is connected to the outlet of the condenser 3, the outlet of the condensate pump 17 is connected to the inlet of the third electric valve 18, and the outlet of the third electric valve 18 is connected to the inlet of the deaerator 4. The condensate pump 17 serves as a driving force to transport the water in the condenser 3 to the deaerator 4, and the third electric valve 18 serves as an isolation valve to control the connection and disconnection between the outlet of the condenser 3 and the inlet of the deaerator 4. The inlet of the third regulating valve 19 is connected to the outlet of the third electric valve 18, and the outlet of the third regulating valve 19 is connected to the inlet of the deaerator 4. When the third electric valve 18 is turned on and the condensate pump 17 is turned on, the third regulating valve 19 can adjust and control the water inlet of the deaerator 4 and control the liquid level of the deaerator 4. The deaerator 4 deoxidizes and heats the condensed water entering the deaerator. The frequency-modulation and peak-shaving unit includes a frequency-modulation steam turbine 5, a clutch 6, a molten salt heat storage device 7, an electric heater 8, a first switch 11, a feed water pump 12, a first electric valve 13, a first regulating valve 14, a second electric valve 15 and a second regulating valve 16. The frequency-modulated steam turbine 5 is coaxially arranged with the generator 2 via a clutch 6 , and the exhaust port of the frequency-modulated steam turbine 5 is connected to the inlet of the condenser 3 . The clutch 6 is a synchronous self-shifting clutch. The molten salt heat storage device 7 includes a salt pool and a heat exchange channel 71. The inlet of the heat exchange channel 71 is connected to the outlet of the deaerator 4, and the outlet of the heat exchange channel 71 is connected to the steam inlet of the frequency-modulated steam turbine 5. The electric heater 8 is connected to the generator 2 to heat the heat storage medium in the salt pool. The heat storage medium absorbs heat and stores energy to realize the energy storage of the molten salt heat storage device 7. When the molten salt heat storage device 7 releases heat, it exchanges heat with the water in the heat exchange channel 71 to heat the water and vaporize it. The vaporized water vapor is discharged into the steam inlet of the frequency-modulated steam turbine 5 to drive the frequency-modulated steam turbine 5 to rotate. The inlet of the water pump 12 is connected to the outlet of the deaerator 4, and the outlet of the water pump 12 is connected to the inlet of the first electric valve 13, and the outlet of the first electric valve 13 is connected to the inlet of the heat exchange channel 71. The water pump 12 serves as a driving force to pump the water in the deaerator 4 into the heat exchange channel 71, and the first electric valve 13 serves as an isolation valve to control the connection and disconnection between the outlet of the deaerator 4 and the inlet of the heat exchange channel 71. The inlet of the first regulating valve 14 is connected to the outlet of the first electric valve 13, and the outlet of the first regulating valve 14 is connected to the inlet of the heat exchange channel 71. When the water pump 12 and the first electric valve 13 are turned on, the first regulating valve 14 can adjust the water inflow of the heat exchange channel 71. The molten salt heat storage device 7 further includes a molten salt pump 72, the inlet of the molten salt pump 72 is connected to the bottom of the salt pool, the outlet of the molten salt pump 72 is connected to the inlet of the electric heater 8 to deliver the heat storage medium in the salt pool to the electric heater 8, and the outlet of the electric heater 8 is connected to the top of the salt pool. After the molten salt pump 72 is turned on, the molten salt at the bottom of the salt pool is pumped into the electric heater 8, and the electric heater 8 is turned on to heat the molten salt inside. With the continuous pumping of the molten salt pump 72, the heated molten salt in the electric heater 8 overflows from the outlet of the electric heater 8 to the top of the salt pool of the molten salt heat storage device 7, and under the action of gravity, the molten salt at the top of the salt pool flows back to the bottom of the salt pool step by step. When the electric heater 8 is turned on, the pumping frequency of the molten salt pump 72 will affect the circulation speed of the molten salt in the molten pool and the electric heater 8, and then affect the temperature of the molten salt in the molten pool, thereby affecting the heat exchange effect with the water in the heat exchange channel 71, and affecting the steam temperature at the outlet of the heat exchange channel 71. A power branch 10 is provided between the transformer 9 and the generator 2, and the power branch 10 is connected to the electric heater 8. A first switch 11 is provided on the power branch 10 to control the on and off of the power branch 10. When the first switch 11 is closed, the power branch 10 is connected, the electric heater 8 is powered on, and the electric heater 8 starts to work. When the first switch 11 is opened, the power branch 10 is disconnected, and the electric heater 8 is powered off. The inlet of the second electric valve 15 is connected to the outlet of the heat exchange channel 71, and the outlet of the second electric valve 15 is connected to the steam inlet of the frequency-modulated steam turbine 5. The second electric valve 15 serves as an isolation valve to control the connection and disconnection between the outlet of the heat exchange channel 71 and the steam inlet of the frequency-modulated steam turbine 5, that is, to control whether the frequency-modulated steam turbine 5 is fed with steam and whether it rotates. Optionally, the inlet of the second regulating valve 16 is connected to the outlet of the second electric valve 15, and the outlet of the second regulating valve 16 is connected to the steam inlet of the frequency-modulated steam turbine 5. When the second electric valve 15 is open, the second regulating valve 16 can adjust and control the steam intake of the frequency-modulated steam turbine 5. When the frequency-modulating and peak-shaving unit of the embodiment of the present application assists the generator set in deep peak-shaving, when the generator set needs to reduce the load, the condensate pump 17 and the feed water pump 12 are shut down, the third electric valve 18 is closed, the first electric valve 13 is closed, the outlet of the deaerator 4 is disconnected from the inlet of the heat exchange channel 71, the molten salt pump 72 is started, the first switch 11 is closed, and the electric heater 8 is turned on to heat the molten salt for heat storage and energy storage. When the generator set needs to increase the load, the condensate pump 17 and the feed water pump 12 are started, the third electric valve 18 is opened, and the first electric valve 13 is opened to send the water in the deaerator 4 to the heat exchange channel 71. During the warm-up stage of the frequency-modulated steam turbine 5, the molten salt pump 72 is in a low-frequency state. When the speed of the frequency-modulated steam turbine 5 is consistent with the speed of the generator, the clutch is closed, and then the frequency of the molten salt pump 72 is gradually increased, and the temperature and flow rate of the steam at the outlet of the heat exchange channel 71 are increased, thereby increasing the speed of the frequency-modulated steam turbine 5.

[0046] When the frequency-modulating and peak-shaving unit of the embodiment of the present application assists the generator set in frequency modulation, the condensate pump 17 and the feed water pump 12 are in the starting state, the third electric valve 18 is opened, the first electric valve 13 is opened, the molten salt pump 72 is turned on, the first switch 11 is closed, and the electric heater 8 is turned on. When the generator set increases its load, the heating power of the electric heater 8 is reduced, and the frequency of the molten salt pump 72 is increased, thereby improving the heat exchange efficiency between the energy storage medium of the molten salt heat storage device 7 and the water in the heat exchange channel 71, and increasing the second regulating valve 16 and the third regulating valve 19 to increase the temperature and flow rate of the water vapor discharged from the heat exchange channel 71, thereby increasing the power of the frequency-modulating steam turbine 5, thereby quickly increasing the output power of the generator 2, and quickly increasing the output power of the transformer 9 to the power grid. When the generator set reduces the load, the heating power of the electric heater 8 is increased, the frequency of the molten salt pump 72 is reduced, thereby reducing the heat exchange efficiency between the energy storage medium of the molten salt heat storage device 7 and the water in the heat exchange channel 71, and the second regulating valve 16 and the third regulating valve 19 are adjusted down to reduce the temperature and flow of the water vapor discharged from the heat exchange channel 71, so that the power of the frequency-modulated steam turbine 5 is reduced, thereby quickly reducing the output power of the generator 2 and the output power of the transformer 9 to the power grid. The frequency-modulated and peak-shaving unit of the embodiment of the present application assists the generator set in frequency modulation, and realizes the response rate of the frequency-modulated and peak-shaving system 100 of the thermal power unit when increasing and decreasing the load. The frequency regulation and peak regulation system 100 of the thermal power unit in the embodiment of the present application adjusts the steam temperature at the outlet of the heat exchange channel 71 by adjusting the frequency of the molten salt pump 72 (that is, the pumping efficiency of the molten salt pump 72), and adjusts the steam flow at the outlet of the heat exchange channel 7 by adjusting the sizes of the second regulating valve 16 and the third regulating valve 19, thereby adjusting the rotation speed of the frequency-regulating steam turbine 5, adjusting the power of the frequency-regulating steam turbine 5, and adjusting the load of the frequency-regulating steam turbine 5, so that the molten salt pump 72, the second regulating valve 16 and the third regulating valve 19 can be automatically adjusted according to the frequency regulation requirements of the generator set to achieve the purpose of rapid frequency regulation of the auxiliary generator set. In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature. In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A frequency and peak regulation system for thermal power units, characterized in that: include: A generator set, the generator set comprising a main steam turbine (1), a generator (2), a condenser (3) and a deaerator (4), the main steam turbine (1) and the generator (2) being coaxially arranged, the exhaust port of the main steam turbine (1) being connected to the inlet of the condenser (3), and the outlet of the condenser (3) being connected to the inlet of the deaerator (4); and A frequency-modulation and peak-shaving unit, the frequency-modulation and peak-shaving unit comprising a frequency-modulation steam turbine (5), a clutch (6), a molten salt heat storage device (7) and an electric heater (8), the frequency-modulation steam turbine (5) being coaxially arranged with the generator (2) via the clutch (6), the exhaust port of the frequency-modulation steam turbine (5) being connected to the inlet of the condenser (3), the molten salt heat storage device (7) comprising a salt pool and a heat exchange channel (71), the inlet of the heat exchange channel (71) being connected to the outlet of the deaerator (4), the outlet of the heat exchange channel (71) being connected to the steam inlet of the frequency-modulation steam turbine (5), and the electric heater (8) being connected to the generator (2) so as to heat the heat storage medium in the salt pool.

2. The frequency and peak regulation system of a thermal power unit according to claim 1, characterized in that: The molten salt heat storage device (7) further comprises a molten salt pump (72), the inlet of the molten salt pump (72) is connected to the bottom of the salt pool, the outlet of the molten salt pump (72) is connected to the inlet of the electric heater (8) to deliver the heat storage medium in the salt pool to the electric heater (8), and the outlet of the electric heater (8) is connected to the top of the salt pool.

3. The frequency and peak regulation system of a thermal power unit according to claim 1, characterized in that: The invention further comprises a transformer (9), wherein the transformer (9) is connected to the generator (2), and the transformer (9) is used to connect to the power grid to integrate the electric energy into the power grid. A power branch (10) is provided between the transformer (9) and the generator (2), and the power branch (10) is connected to the electric heater (8); The frequency-modulation and peak-modulation unit further comprises a first switch (11), wherein the first switch (11) is arranged on the power branch (10) to control the on and off of the power branch (10).

4. The frequency and peak regulation system of a thermal power unit according to claim 1, characterized in that: The frequency-modulation and peak-shaving unit further comprises a water feed pump (12) and a first electric valve (13), wherein the inlet of the water feed pump (12) is connected to the outlet of the deaerator (4), the outlet of the water feed pump (12) is connected to the inlet of the first electric valve (13), and the outlet of the first electric valve (13) is connected to the inlet of the heat exchange channel (71).

5. The frequency and peak regulation system of a thermal power unit according to claim 4, characterized in that: The frequency-modulation and peak-shaving unit further comprises a first regulating valve (14), the inlet of the first regulating valve (14) is connected to the outlet of the first electric valve (13), and the outlet of the first regulating valve (14) is connected to the inlet of the heat exchange channel (71).

6. The frequency and peak regulation system of a thermal power unit according to claim 1, characterized in that: The peak-shaving and frequency-regulating unit further comprises a second electric valve (15), the inlet of the second electric valve (15) is connected to the outlet of the heat exchange channel (71), and the outlet of the second electric valve (15) is connected to the steam inlet of the frequency-regulating steam turbine (5).

7. The frequency and peak regulation system of a thermal power unit according to claim 6, characterized in that: The peak-shaving and frequency-regulating unit further comprises a second regulating valve (16), the inlet of the second regulating valve (16) is connected to the outlet of the second electric valve (15), and the outlet of the second regulating valve (16) is connected to the steam inlet of the frequency-regulating steam turbine (5).

8. The frequency and peak regulation system of a thermal power unit according to claim 1, characterized in that: The generator set further includes a condensate pump (17) and a third electric valve (18), the inlet of the condensate pump (17) is connected to the outlet of the condenser (3), the outlet of the condensate pump (17) is connected to the inlet of the third electric valve (18), and the outlet of the third electric valve (18) is connected to the inlet of the deaerator (4).

9. The frequency and peak regulation system of a thermal power unit according to claim 8, characterized in that: The generator set further comprises a third regulating valve (19), the inlet of the third regulating valve (19) is connected to the outlet of the third electric valve (18), and the outlet of the third regulating valve (19) is connected to the inlet of the deaerator (4).

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