Power generation system

Abstract

This invention discloses a power generation system comprising a power generation unit, an annular cooling unit, and a thermal storage unit. The outlet of the annular cooling unit is connected to the inlet of the power generation unit via a supply pipeline, and the return cooling port of the annular cooling unit is connected to the exhaust port of the power generation unit via a return cooling pipeline, forming a circulation pipeline. The first inlet and outlet of the thermal storage unit are connected to one end of the supply pipeline, and the second inlet and outlet of the thermal storage unit are connected to the other end of the supply pipeline and also connected to the return cooling pipeline, for absorbing heat from the flue gas and releasing heat to the flue gas. This invention improves the coupling method between the thermal storage unit and the multi-stage inlet waste heat furnace, forming a peak-shaving power generation system with the thermal storage unit coupled to the multi-stage inlet waste heat furnace. By changing the coupling method, the heat energy transfer mode in the system during the charging and releasing processes is altered, thereby solving problems such as poor main steam quality of the waste heat furnace, poor turbine stability, and large weight of the thermal storage unit.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage technology, and more particularly to a power generation system. Background Technology

[0002] The existing power generation system is equipped with a circulating fan, a heat charging switching valve, and a heat dissipation switching valve on the flue gas circulation side. The normal operation, heat charging, and heat dissipation processes are completed through the frequency conversion regulation of the circulating fan and the operation of each valve.

[0003] Normal process: All flue gas from the first stage of the annular cooling system enters the superheater inlet of the annular cooling waste heat furnace, and all flue gas from the second stage enters the superheater outlet of the annular cooling waste heat furnace. After the flue gas from the first stage cools down, it mixes with the flue gas from the second stage at the superheater outlet and flows sequentially through each heating surface of the waste heat furnace. After releasing heat within the annular cooling waste heat furnace, the flue gas returns from the waste heat furnace exhaust port to the annular cooling air box via an induced draft fan. With a certain amount of forced air, it is then sent to the annular cooler to cool the sintered material.

[0004] The heating process involves taking a portion of the flue gas from the first stage of the annular cooling system and charging it into a solid heat storage device. The heated, low-temperature flue gas is then returned to the first stage of the annular cooling system and mixed with the remaining flue gas. The temperature of the mixed flue gas from the first stage of the annular cooling system decreases before it enters the superheater inlet of the annular cooling waste heat furnace.

[0005] Heat release process: A portion of the flue gas from the exhaust gas of the annular cooling waste heat furnace or the flue gas from the third stage of the annular cooling system is taken into the solid heat storage device for heat release. The released flue gas is then returned to the flue gas in the first stage of the annular cooling system for mixing. The temperature of the mixed flue gas in the first stage of the annular cooling system decreases and the flow rate increases before it enters the superheater inlet of the annular cooling waste heat furnace.

[0006] However, during the heat charging process, the temperature of the mixed flue gas in the annular cooling section decreases, leading to a reduction in the superheat of the main steam. Therefore, the quality of the main steam entering the turbine is significantly affected by the heat charging process, impacting the turbine's stable operation. Furthermore, during the heat release process, the temperature of the mixed flue gas in the annular cooling section decreases while the flow rate increases. The decrease in flue gas temperature further reduces the superheat of the main steam, also affecting the turbine's stable operation. Summary of the Invention

[0007] The main objective of this invention is to provide a power generation system that improves the stability of a steam turbine.

[0008] To achieve the above objectives, the present invention proposes a power generation system, the power generation system comprising:

[0009] Power generation equipment;

[0010] A circulating cooling device, wherein the outlet of the circulating cooling device is connected to the inlet of the power generation device via a supply pipeline, and the return cooling port of the circulating cooling device is connected to the exhaust port of the power generation device via a return cooling pipeline, forming a circulation pipeline; and

[0011] A heat storage device, wherein the first inlet and outlet of the heat storage device are connected to one end of the gas supply pipeline, and the second inlet and outlet of the heat storage device are connected to the other end of the gas supply pipeline and to the return cooling pipeline, for absorbing heat from the flue gas and releasing heat to the flue gas.

[0012] Optionally, the power generation device includes a waste heat furnace, a steam turbine connected to the waste heat furnace, and a generator connected to the steam turbine; wherein the waste heat furnace has a first air inlet and a second air inlet;

[0013] The annular cooling device includes an annular cooler with a first air outlet and a second air outlet. The air supply pipeline includes a first annular cooling pipeline and a second annular cooling pipeline. The first air outlet of the annular cooler is connected to the first air inlet of the waste heat furnace through the first annular cooling pipeline. The second air outlet of the annular cooler is connected to the second air inlet of the waste heat furnace through the second annular cooling pipeline. The return cooling port of the annular cooler is connected to the exhaust port of the waste heat furnace through the return cooling pipeline for cooling the sintering material.

[0014] The first inlet and outlet of the heat storage device are connected to the first annular cooling pipeline through an air inlet pipeline, the second inlet and outlet of the heat storage device are connected to the second annular cooling pipeline through an air outlet pipeline, and the second inlet and outlet of the heat storage device are connected to the return cooling pipeline, and the air outlet pipeline is connected to the return cooling pipeline.

[0015] Optionally, a mixer is provided on the second annular cooling pipeline, and the outlet pipeline is connected to the inlet of the mixer.

[0016] Optionally, the intake pipe is provided with a first heating valve, and the outlet pipe is provided with a second heating valve and a mixing valve.

[0017] Optionally, the air inlet pipe and the air outlet pipe are connected through a heat release branch, and the heat release branch is provided with a first heat release valve and a second heat release valve.

[0018] Optionally, a dust collector is also provided on the air inlet pipe, and a heat storage circulating fan is also provided on the air outlet pipe.

[0019] Optionally, a third heat release valve is provided on the pipeline between the second inlet and outlet of the heat storage device and the return cooling pipeline, and an emergency discharge valve is provided on the pipeline between the outlet pipeline and the return cooling pipeline. The inlet of the emergency discharge valve is connected to the outlet of the heat storage circulating fan.

[0020] Optionally, the waste heat furnace also has a third air inlet, which is located on the low-pressure evaporation section of the waste heat furnace. The air outlet of the heat storage circulating fan is connected to the third air inlet through a connecting pipe, and a low-temperature discharge valve is provided on the connecting pipe.

[0021] Optionally, a ring-cooled induced draft fan is provided on the return cooling pipeline.

[0022] Optionally, the exhaust port of the waste heat furnace is connected to the inlet of the steam turbine, and the exhaust port of the steam turbine is connected to the return water port of the waste heat furnace through a return water pipeline. A condenser, a condensate pump, a deaerator, and a feed water pump are sequentially arranged on the return water pipeline from the exhaust port of the steam turbine to the return water port of the waste heat furnace.

[0023] In the technical solution of the present invention, the power generation system includes a power generation device, an annular cooling device, and a heat storage device; the outlet of the annular cooling device is connected to the inlet of the power generation device through a gas supply pipeline, and the return cooling port of the annular cooling device is connected to the exhaust port of the power generation device through a return cooling pipeline to form a circulation pipeline; the first inlet and outlet of the heat storage device are connected to one end of the gas supply pipeline, and the second inlet and outlet of the heat storage device are connected to the other end of the gas supply pipeline and connected to the return cooling pipeline, so as to absorb heat from the flue gas and release heat to the flue gas.

[0024] During the heating process, a portion of the flue gas from the first stage of the annular cooler is drawn and heated through the heat storage device. Specifically, the flue gas enters the heat storage device from the first outlet of the annular cooler via the first annular cooling pipeline. After heating, the temperature of this flue gas is appropriately reduced to ensure that the average heating temperature of the heat storage device remains relatively high. After cooling, the heated flue gas is mixed with the flue gas from the second stage of the annular cooler. This cooled flue gas is then introduced into the second annular cooling pipeline and mixed with the high-temperature flue gas therein. Therefore, the quality of the remaining first-stage flue gas and the superheat of the main steam are not affected. Simultaneously, the temperature of the mixed second-stage flue gas remains above the main steam evaporation temperature, ensuring the main steam evaporation rate. Consequently, the superheat and flow rate of the main steam do not fluctuate drastically due to energy loss during heating, ensuring the quality and flow rate of the main steam, and thus guaranteeing the stable operation of the turbine.

[0025] During heat release, a portion of the waste heat furnace exhaust gas is drawn and flows through the heat storage device for heat release. Specifically, the exhaust gas flows from the waste heat furnace's exhaust port through the return cooling pipe to the second inlet and outlet of the heat storage device for heat release. This exhaust gas experiences a slight temperature increase after heat release, ensuring that the average temperature of the heat storage device remains relatively low during heat release. After the heat-released flue gas heats up, it mixes with the flue gas in the second annular cooling section. This means the heated flue gas is introduced into the second annular cooling pipe and mixes with the flue gas therein. Therefore, it does not affect the temperature and flow rate of the first-stage flue gas, and consequently, it does not affect the superheat of the main steam or the shell-side velocity of the superheater. The mixed second-stage flue gas has a lower temperature and increased flow rate, but the flue gas temperature remains above the evaporation temperature of the main steam, ensuring the main steam evaporation rate. Therefore, the superheat of the main steam will not fluctuate drastically due to the agitation of the low-temperature flue gas during heat release, ensuring that the boiler and turbine operate at maximum output during heat release. Furthermore, because the sintering ring cooling waste heat furnace is designed and operated with a large temperature difference between the flue gas temperature in the second stage of the ring cooling and the evaporation temperature of the main steam, the hot flue gas after absorbing heat from the heat storage device only needs to maintain a low flue gas temperature to ensure that the temperature of the mixed second stage flue gas is maintained within the allowable end difference range of the main steam evaporation temperature. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an embodiment of the power generation system of the present invention;

[0028] Figure 2 This is a schematic diagram of another embodiment of the power generation system of the present invention.

[0029] Explanation of icon numbers:

[0030] 10. Power generation unit; 20. Circulating cooling unit; 30. Thermal storage unit; 11. Waste heat furnace; 12. Steam turbine; 13. Generator; 211. First circulating cooling pipeline; 212. Second circulating cooling pipeline; 213. Return cooling pipeline; 214. Low temperature discharge valve; 311. Inlet pipeline; 312. Outlet pipeline; 22. Mixer; 201. Dust collector; 202. First heat charging valve; 203. First heat release valve; 204. Second heat charging valve; 205. Thermal storage circulating fan; 206. Mixing valve; 207. Second heat release valve; 208. Third heat release valve; 209. Emergency discharge valve; 210. Circulating cooling induced draft fan; 121. Condenser; 122. Condensate pump; 123. Deaerator; 124. Feed water pump.

[0031] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0034] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0035] This invention proposes a power generation system, and more particularly a sintering ring cooling waste heat power generation system with thermal storage and peak shaving functions.

[0036] Reference Figure 1 The power generation system includes a power generation device 10, an annular cooling device 20, and a heat storage device 30. The outlet of the annular cooling device 20 is connected to the inlet of the power generation device 10 through a gas supply pipeline, and the return cooling port of the annular cooling device 20 is connected to the exhaust port of the power generation device 10 through a return cooling pipeline, forming a circulation pipeline. The first inlet and outlet of the heat storage device 30 are connected to one end of the gas supply pipeline, and the second inlet and outlet of the heat storage device 30 are connected to the other end of the gas supply pipeline and connected to the return cooling pipeline 213, so as to absorb heat from the flue gas and release heat to the flue gas.

[0037] In this embodiment, the power generation device 10 includes a waste heat furnace 11, a steam turbine 12 connected to the waste heat furnace 11, and a generator 13 connected to the steam turbine 12; the waste heat furnace 11 may have a first air inlet and a second air inlet. The annular cooling device 20 includes an annular cooler, which may be correspondingly provided with a first air outlet and a second air outlet. The air supply pipeline may include a first annular cooling pipeline 211 and a second annular cooling pipeline 212. The first air outlet of the annular cooler is connected to the first air inlet of the waste heat furnace 11 through the first annular cooling pipeline 211, and the second air outlet of the annular cooler is connected to the second air inlet of the waste heat furnace 11 through the second annular cooling pipeline 212. The return cooling port of the annular cooler is connected to the exhaust port of the waste heat furnace 11 through the return cooling pipeline 213 for cooling the sintering material. The first inlet and outlet of the heat storage device 30 are connected to the first annular cooling pipe 211 through the air inlet pipe 311, the second inlet and outlet of the heat storage device 30 are connected to the second annular cooling pipe 212 through the air outlet pipe 312, and the second inlet and outlet of the heat storage device 30 are connected to the return cooling pipe 213, and the air outlet pipe 312 is connected to the return cooling pipe 213.

[0038] Of course, in some other embodiments, the waste heat furnace 11 may also be provided with more air inlets, and the corresponding annular cooler may be provided with more air outlets, which is not limited here.

[0039] In this embodiment, the waste heat furnace 11 can be a sintering ring cooling waste heat boiler.

[0040] Reference Figure 1 The exhaust port of the waste heat furnace 11 is connected to the inlet of the steam turbine 12, and the exhaust port of the steam turbine 12 is connected to the return water port of the waste heat furnace 11 through a return water pipeline. A condenser 121, a condensate pump 122, a deaerator 123, and a feedwater pump 124 are sequentially installed on the return water pipeline from the exhaust port of the steam turbine 12 to the return water port of the waste heat furnace 11. The feedwater pump 124 is used to increase the return water rate.

[0041] In this embodiment, the heat storage device 30 can be a solid heat storage device or the like, and is not limited here.

[0042] Solid thermal storage devices can be cast from silicate solid thermal storage materials with high thermal density and high stability, and can be assembled using a modular design. Each module can be arranged in a vertical grid pattern. Flow guides can be installed at the inlet and outlet of the solid thermal storage device to evenly distribute the flue gas during the charging and releasing processes. A screw conveyor can be installed at the bottom of the solid thermal storage device for periodic ash removal.

[0043] It is worth mentioning that the main parameters for designing and selecting solid thermal storage devices include, but are not limited to: the volume of flue gas flowing through for heat charging, the volume of flue gas flowing through for heat dissipation, the flue gas temperatures at the inlet and outlet for heat charging, and the flue gas temperatures at the inlet and outlet for heat dissipation. These parameters can be used to determine the technical and economic indicators of the solid thermal storage device, such as the weight of the storage material and the device resistance.

[0044] During the heating process, a portion of the flue gas from the first stage of the annular cooler is drawn and heated through the heat storage device 30. Specifically, the flue gas enters the heat storage device 30 from the first outlet of the annular cooler via the first annular cooling pipe 211. After heating, the temperature of this flue gas is appropriately reduced to ensure that the average heating temperature of the heat storage device 30 remains relatively high. After cooling, the heated flue gas is mixed with the flue gas from the second stage of the annular cooler. This cooled flue gas is then introduced into the second annular cooling pipe 212, where it mixes with the high-temperature flue gas. Therefore, the quality of the remaining first-stage flue gas and the superheat of the main steam are not affected. Simultaneously, the temperature of the mixed second-stage flue gas remains above the main steam evaporation temperature, ensuring the main steam evaporation rate. Consequently, the superheat and flow rate of the main steam do not fluctuate drastically due to energy loss during heating, ensuring the quality and flow rate of the main steam, and thus guaranteeing the stable operation of the turbine 12.

[0045] During heat release, a portion of the flue gas from the waste heat furnace 11 is drawn and flows through the heat storage device 30 for heat release. Specifically, the flue gas flows from the exhaust port of the waste heat furnace 11 through the return cooling pipe 213 to the second inlet and outlet of the heat storage device 30 for heat release. The temperature of this flue gas increases appropriately after heat release, ensuring that the average temperature of the heat storage device 30 remains relatively low during heat release. After the heated flue gas reaches a higher temperature, it mixes with the flue gas in the second annular cooling section. That is, the heated flue gas is introduced into the second annular cooling pipe 212 and mixes with the flue gas therein. Therefore, it does not affect the temperature and flow rate of the first-stage flue gas, and consequently, it does not affect the superheat of the main steam or the shell-side velocity of the superheater. The temperature of the mixed second-stage flue gas decreases and the flow rate increases, but the flue gas temperature remains above the evaporation temperature of the main steam, ensuring the evaporation rate of the main steam. Therefore, the superheat of the main steam will not fluctuate drastically due to the agitation of the low-temperature flue gas during heat release, ensuring that the boiler and turbine 12 operate at maximum output during heat release. Furthermore, because the sintering ring cooling waste heat furnace 11 has the characteristic of a large difference between the flue gas temperature of the second stage of the ring cooling and the evaporation temperature of the main steam under its design and operation conditions, the hot flue gas after absorbing heat from the heat storage device 30 only needs to maintain a low flue gas temperature to ensure that the temperature of the second stage flue gas after mixing is maintained within the allowable end difference range of the evaporation temperature of the main steam.

[0046] Understandably, because the quality of the main steam in the charging and discharging states of the power generation system is guaranteed, the operating range of the sliding parameters of the steam turbine 12 is reduced, thus minimizing the impact of the solid thermal storage device on the original waste heat power generation system.

[0047] To further improve the uniformity of the second-stage flue gas temperature and reduce its impact on the stability of turbine 12, refer to Figure 1 In one embodiment, a mixer 22 is provided on the second annular cooling pipe 212, and the air outlet pipe 312 is connected to the air inlet of the mixer 22.

[0048] In this embodiment, a dust collector 201 and a first heating valve 202 may be provided on the air intake pipe 311.

[0049] Among them, dust collector 201 can be a cyclone dust collector, which can remove dust from flue gas.

[0050] Furthermore, the inlet pipe 311 and the outlet pipe 312 are connected via a heat release branch. The heat release branch is equipped with a first heat release valve 203 and a second heat release valve 207, which are respectively located near both ends of the heat storage device 30. The outlet pipe 312 is equipped with a second heat charging valve 204, a heat storage circulating fan 205, and a mixing valve 206. A third heat release valve 208 is installed on the pipe between the second inlet / outlet of the heat storage device 30 and the return cooling pipe 213. An emergency discharge valve 209 is installed on the pipe between the outlet pipe 312 and the return cooling pipe 213, with the inlet end of the emergency discharge valve 209 connected to the outlet of the heat storage circulating fan 205. A cooling induced draft fan 210 is installed on the return cooling pipe 213.

[0051] In this embodiment, the second heat charging valve 204 is located between the connection point of the outlet pipe 312 to the heat release branch and the connection point of the outlet pipe 312 to the return cooling pipe 213.

[0052] Among them, the thermal storage circulating fan 205 and the annular cooling induced draft fan 210 can accelerate the flow of flue gas, thereby improving power generation efficiency.

[0053] The power generation system in this embodiment has the following states:

[0054] 1) When the power generation system is in normal state, the first heat charging valve 202, the first heat dissipation valve 203, the third heat dissipation valve 208, the second heat charging valve 204, the second heat dissipation valve 207, the mixing valve 206, and the emergency discharge valve 209 are closed.

[0055] 2) When the power generation system is in a charging state, the first charging valve 202, the second charging valve 204, and the mixing valve 206 are opened, and the first heat release valve 203, the third heat release valve 208, the second heat release valve 207, and the emergency discharge valve 209 are closed.

[0056] 3) When the power generation system is in the heat release state, the first heat release valve 203, the third heat release valve 208, the second heat release valve 207, and the mixing valve 206 are opened, and the first heat charging valve 202 and the second heat charging valve 204 are closed.

[0057] 4) When the power generation system is in the emergency discharge phase, that is, when an abnormal flue gas temperature is detected at the outlet of the thermal storage circulating fan 205, the mixing valve 206 is closed and the emergency discharge valve 209 is opened to carry out emergency discharge.

[0058] The power generation system of this invention, by setting an emergency discharge valve, ensures that flue gas that has not reached the required temperature during the charging and discharging states is discharged to the tail end of the boiler, without affecting the boiler interior or the quality of the steam.

[0059] It should be noted that, in order to achieve better stability of the steam turbine 12, the design principles for the configuration parameters of the solid thermal energy storage device in the power generation system of this invention and the control method of the flue gas circulation side during the operation of the control system are as follows:

[0060] Because the temperature of the flue gas flowing through the solid thermal storage device decreases during charging, the configuration parameters of the solid thermal storage device should take into account the flow rate and temperature drop of the charging flue gas. This ensures that the mixed flue gas temperature after the cooled flue gas is mixed with the second-stage flue gas is higher than the main steam evaporation temperature and the design temperature difference of the heat exchanger. During operation control, the temperature and flow rate measuring points at the solid thermal storage device and the flue can be used to provide feedback and adjust the variable frequency thermal storage circulating fan 205. The valve openings in each charging process can also be used for correction adjustments.

[0061] Because the flue gas temperature rises during heat release as it flows through the solid thermal storage device, the configuration parameters of the solid thermal storage device should take into account the volume and temperature rise of the flue gas flowing through it. It is necessary to ensure that the mixed flue gas temperature after the heated flue gas is mixed with the secondary flue gas is higher than the main steam evaporation temperature and the design temperature difference of the heat exchanger. During operation control, the temperature and flow rate measuring points at the solid thermal storage device and flue can be used to provide feedback and adjust the variable frequency thermal storage circulating fan 205, and the valve openings in each heat release process can be used for correction adjustments.

[0062] During emergency smoke discharge, the status of emergency discharge valve 209 can be adjusted by using the temperature measuring points at the solid heat storage device and the flue.

[0063] It should also be noted that in existing technologies, the superheater has a small heating area and limited installation space. Increased flue gas flow causes a sharp increase in the flow velocity on the superheater shell side, affecting the superheater's lifespan. However, in the power generation system of this invention, when in the exothermic state, the flue gas flow velocity through the superheater is guaranteed, preventing severe scouring that could affect the superheater's service life.

[0064] Furthermore, in the heat release process of existing power generation equipment, in order to maintain the temperature of the mixed flue gas in the first stage of the annular cooling system within the allowable operating range of the waste heat furnace 11, the outlet temperature of the hot flue gas from the solid thermal storage device must be relatively high. The allowable reduction in the outlet flue gas temperature of the solid thermal storage device is limited, making it impossible to maximize the average temperature difference of the solid thermal storage device. Therefore, the charging and discharging end-point difference of the solid thermal storage device in such power generation systems is small, resulting in a large weight of the required solid thermal storage device, which is not technically economical. However, in the power generation system of this invention, during heat release, a portion of the exhaust gas from the waste heat furnace 11 flows through the solid thermal storage device. Maintaining the outlet flue gas temperature of the solid thermal storage device at a relatively low temperature ensures that the mixed second-stage flue gas temperature is within the allowable end-point difference range of the main steam evaporation temperature. Therefore, the average temperature of the solid thermal storage device is minimized during heat release, and the average temperature difference of the solid thermal storage device is maximized during charging and discharging. Therefore, compared with existing power generation systems, the power generation system of this invention has the least weight of thermal storage material for the same thermal storage capacity, representing the optimal weight configuration of the solid thermal storage device.

[0065] In another embodiment, reference Figure 2 The waste heat furnace 11 may also have a third air inlet, which is located on the low-pressure evaporation section of the waste heat furnace 11. The air outlet of the heat storage circulating fan 205 is connected to the third air inlet through a connecting pipe, and a low-temperature discharge valve 214 is provided on the connecting pipe. That is, the air inlet end of the connecting pipe is connected to the air outlet of the heat storage circulating fan 205, and the air outlet end of the connecting pipe is connected to the low-pressure evaporation section of the waste heat furnace 11.

[0066] In this embodiment, the connecting pipeline and the low-temperature discharge valve 214 on it are optional design modules. These optional design modules require the low-pressure evaporation section of the waste heat furnace 11 to have corresponding physical space.

[0067] It is worth noting that the waste heat furnace 11 configured in the annular cooler of the annular cooling device 20 is a dual-pressure waste heat furnace, that is, it has a medium-pressure section (or high-pressure section) and a low-pressure section. The flue gas from the first and second annular cooling sections first flows through the medium-pressure section (or high-pressure section) of the waste heat furnace 11, then flows through the low-pressure section, and finally is discharged from the exhaust port at the tail end of the waste heat furnace 11.

[0068] It should be noted that the low-temperature discharge valve 214, the mixing valve 206, and the emergency discharge valve 209 can switch states based on the feedback value from the flue gas temperature measuring point at the outlet of the thermal storage device 30.

[0069] 1) When the power generation system is in normal state, the first heat charging valve 202, the first heat dissipation valve 203, the third heat dissipation valve 208, the second heat charging valve 204, the second heat dissipation valve 207, the mixing valve 206, the emergency discharge valve 209, and the low temperature discharge valve 214 are closed.

[0070] 2) When the power generation system is in a charging state, the first charging valve 202 and the second charging valve 204 are open, and the first heat release valve 203, the third heat release valve 208, and the second heat release valve 207 are closed. The three valves, namely the mixing valve 206, the low-temperature discharge valve 214, and the emergency discharge valve 209, can be judged and switched according to the feedback value of the flue gas temperature measuring point at the outlet of the thermal storage device 30.

[0071] During the heating state, the judgment conditions and switching methods for the three valves, namely mixing valve 206, cryogenic discharge valve 214, and emergency discharge valve 209, are as follows:

[0072] In the initial stage of the heating process, a portion of the flue gas from the annular cooling section flows through the heat storage device 30. The heat storage device 30 needs to absorb the heat carried by this portion of the flue gas, so the outlet flue gas temperature of the heat storage device 30 is relatively low. As the heat storage device 30 is heated by the high-temperature flue gas at the inlet, the outlet flue gas temperature of the heat storage device 30 gradually increases to the design value of the heating outlet flue gas temperature.

[0073] Judgment condition (A) during the heat charging process: When the flue gas temperature measured at the outlet of the heat storage device 30 is lower than the saturation temperature corresponding to the low-pressure steam drum of the waste heat furnace 11, the emergency discharge valve 209 opens, and the mixing valve 206 and the low-temperature discharge valve 214 close. The flue gas from the outlet of the heat storage device 30 is discharged to the corresponding position at the tail of the waste heat furnace 11, which can prevent excessively low-temperature flue gas from entering the waste heat furnace 11 and reduce the disturbance of low-temperature flue gas to the steam quality of the waste heat furnace 11. This judgment condition also applies to power generation systems that have not selected this design module.

[0074] Judgment condition (B) during the heat charging process: When the flue gas temperature measured at the outlet of the heat storage device 30 is higher than the saturation temperature corresponding to the low-pressure steam drum of the waste heat furnace 11, but lower than the saturation temperature corresponding to the medium (high) pressure steam drum, the low-temperature discharge valve 214 opens, and the emergency discharge valve 209 and the mixing valve 206 close. The flue gas at the outlet of the heat storage device 30 enters the low-pressure evaporation section of the waste heat furnace 11, recovering the waste heat from the annular cooling into the low-pressure steam.

[0075] Under the given conditions, the power generation system without this design module causes the low-temperature flue gas to mix with the flue gas from the second stage of the annular cooling system before entering the medium (high) pressure evaporation section. For the medium (high) pressure evaporation heating surface, the flue gas temperature in the second stage of the annular cooling system decreases slightly after mixing, but the flue gas volume in the second stage of the annular cooling system increases. Conversely, the power generation system with this design module, under the same conditions, causes the low-temperature flue gas to enter the low-pressure evaporation section. For the medium (high) pressure evaporation heating surface, there is no disturbance to the flue gas temperature in the second stage of the annular cooling system, but the flue gas volume in the second stage of the annular cooling system does not increase. Under these conditions, both power generation systems with and without this design module have a certain degree of positive impact.

[0076] The results of the design analysis are as follows: In terms of the impact of the thermal storage device 30 on the stability of the power generation system, the effect of this part of the low-temperature flue gas entering the low-pressure evaporation section is better than that of entering the medium (high) pressure evaporation section, with an effect improvement of about 3%.

[0077] Judgment condition (C) during the heat charging process: When the flue gas temperature measured at the outlet of the heat storage device 30 is higher than the saturation temperature corresponding to the medium (high) pressure steam drum of the waste heat furnace 11, the mixing valve 206 opens, and the low-temperature discharge valve 214 and the emergency discharge valve 209 close. The outlet flue gas of the heat storage device 30 enters the mixer 22 and mixes with the flue gas from the second stage of the annular cooling system before entering the medium (high) pressure evaporation section. This judgment condition also applies to power generation systems that have not selected this design module.

[0078] 3) When the power generation system is in a heat release state, the first heat release valve 203, the third heat release valve 208, and the second heat release valve 207 are open, while the first heat charging valve 202 and the second heat charging valve 204 are closed. The three valves, namely the mixing valve 206, the low-temperature discharge valve 214, and the emergency discharge valve 209, can be judged and switched according to the feedback value of the flue gas temperature measuring point at the outlet of the thermal storage device 30.

[0079] In the exothermic state, the judgment conditions and switching methods for the three valves, namely mixing valve 206, cryogenic discharge valve 214, and emergency discharge valve 209, are as follows:

[0080] In the initial stage of the exothermic state, part of the exhaust gas from the waste heat furnace 11 flows through the heat storage device 30. At this time, the heat storage device 30 carries a large amount of heat and is in a high-energy state, so the outlet flue gas temperature of the heat storage device 30 is relatively high. As the heat storage device 30 absorbs heat from the low-temperature exhaust gas at the inlet, the flue gas temperature at the outlet of the heat storage device 30 gradually decreases to the design value of the exothermic outlet flue gas temperature.

[0081] In the heat release state, the state of the mixing valve 206 and the low temperature discharge valve 214 can still be controlled based on the feedback value of the outlet flue gas temperature measuring point of the heat storage device 30 and the saturation temperature corresponding to the medium (high) pressure steam drum of the waste heat furnace 11, so as to select whether to merge the outlet flue gas of the heat storage device into the low-pressure evaporation section or the medium (high) pressure evaporation section during heat release.

[0082] When designing a thermal energy storage device, the design value of the heat release outlet flue gas temperature should be greater than or equal to the saturation temperature value corresponding to the medium (high) pressure steam drum, so as to maximize the benefits of the stored thermal energy during the release process.

[0083] In summary, this invention improves the coupling method between the solid thermal energy storage device and the multi-stage inlet ring-cooled waste heat furnace 11, forming a new peak-shaving power generation system with a solid thermal energy storage device coupled to the multi-stage inlet ring-cooled waste heat furnace 11. By changing the coupling method, the heat energy transfer mode in the system during the charging and releasing processes is altered, thereby effectively solving problems such as poor main steam quality of the waste heat furnace 11, poor stability of the turbine 12, and large weight of the solid thermal energy storage device in existing power generation systems.

[0084] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A power generation system, characterized in that, The power generation system includes: A power generation device, comprising a waste heat furnace, a steam turbine connected to the waste heat furnace, and a generator connected to the steam turbine; wherein the waste heat furnace has a first air inlet and a second air inlet; A ring cooling device is provided, wherein the outlet of the ring cooling device is connected to the inlet of the power generation device via a gas supply pipeline, and the return cooling port of the ring cooling device is connected to the exhaust port of the power generation device via a return cooling pipeline, forming a circulation pipeline; the ring cooling device includes a ring cooler having a first outlet and a second outlet, the gas supply pipeline includes a first ring cooling pipeline and a second ring cooling pipeline, the first outlet of the ring cooler is connected to the first inlet of the waste heat furnace via the first ring cooling pipeline, the second outlet of the ring cooler is connected to the second inlet of the waste heat furnace via the second ring cooling pipeline, and the return cooling port of the ring cooler is connected to the exhaust port of the waste heat furnace via the return cooling pipeline for cooling the sintering material; and A heat storage device is provided, wherein the first inlet and outlet of the heat storage device are connected to the first annular cooling pipe through an air inlet pipe, the second inlet and outlet of the heat storage device are connected to the second annular cooling pipe through an air outlet pipe, and the second inlet and outlet of the heat storage device are connected to the return cooling pipe, and the air outlet pipe is connected to the return cooling pipe. The heat storage device is used to absorb heat from the flue gas and release heat to the flue gas.

2. The power generation system as described in claim 1, characterized in that, A mixer is provided on the second annular cooling pipeline, and the outlet pipeline is connected to the inlet of the mixer.

3. The power generation system as described in claim 1, characterized in that, The intake pipe is equipped with a first heating valve, and the outlet pipe is equipped with a second heating valve and a mixing valve.

4. The power generation system as described in claim 3, characterized in that, The air inlet pipe and the air outlet pipe are connected by a heat release branch, which is equipped with a first heat release valve and a second heat release valve.

5. The power generation system as described in claim 4, characterized in that, The air intake pipe is also equipped with a dust collector, and the air outlet pipe is also equipped with a heat storage circulating fan.

6. The power generation system as described in claim 5, characterized in that, A third heat release valve is provided on the pipeline between the second inlet and outlet of the thermal storage device and the return cooling pipeline. An emergency discharge valve is provided on the pipeline between the outlet pipeline and the return cooling pipeline. The inlet of the emergency discharge valve is connected to the outlet of the thermal storage circulating fan.

7. The power generation system as described in claim 6, characterized in that, The waste heat furnace also has a third air inlet, which is located on the low-pressure evaporation section of the waste heat furnace. The air outlet of the heat storage circulating fan is connected to the third air inlet through a connecting pipe, and a low-temperature discharge valve is provided on the connecting pipe.

8. The power generation system as described in claim 1, characterized in that, The return cooling pipeline is equipped with a ring cooling induced draft fan.

9. The power generation system as described in claim 8, characterized in that, The exhaust port of the waste heat furnace is connected to the inlet of the steam turbine, and the exhaust port of the steam turbine is connected to the return water port of the waste heat furnace through a return water pipeline. A condenser, a condensate pump, a deaerator, and a feed water pump are sequentially arranged on the return water pipeline from the exhaust port of the steam turbine to the return water port of the waste heat furnace.

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