Solid electric heat accumulator and converter waste heat utilization device system and method

Abstract

The invention relates to a solid electric heat accumulator, a converter waste heat utilization device system and a converter waste heat utilization method. A solid electric heat storage unit is arranged, saturated steam is overheated by a waste heat boiler and then enters a steam turbine unit, so that the steam dryness of an outlet of the steam turbine is greatly improved, meanwhile, the pressure of a condenser can be further reduced, and the unit efficiency is improved; due to the arrangement of the solid electric heat accumulator, the unit has an energy storage function; the shaft seal leaked gas of the turbine high-pressure cylinder is heated by the shaft seal heater, mixed with the steam discharged by the steam-water separator and then enters the turbine low-pressure cylinder, so that the steam leakage loss of the turbine is reduced, the steam discharge dryness of an outlet is further improved, and the efficiency of the turbine low-pressure cylinder is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and in particular to a solid electric heat storage body, a device system and a method for utilizing waste heat of a converter. Background Art

[0002] The converter is an important part of the steel production process. The flue gas produced by the converter carries a lot of heat. In order to protect the converter flue, cooling water pipes are generally arranged inside the flue to reduce the flue wall temperature through the vaporization cooling effect of water. At the same time, the cooling water in the cooling water pipe is heated by the high-temperature flue gas to become steam, taking away the heat. Some companies release this part of the steam, resulting in a large amount of energy waste. Some companies use waste heat steam to generate electricity, but the high-temperature flue gas produced by the converter is discontinuous. At present, waste heat boilers, steam accumulators and saturated generator sets are usually used to utilize steam, and the power generation efficiency is less than 20%, and it is impossible to ensure the smooth, safe and reliable operation of the steam turbine and the saturated generator set.

[0003] CN203148247U discloses a converter steam sintering waste heat combined utilization power generation system, comprising a steam collecting cylinder (9), a steam turbine (1), a condenser (3), a condensate pump (4), a vacuum deaerator (7) and a water pump (8) connected in sequence, and also comprising a heat accumulator (11), a steam heating furnace (10) and a sintering waste heat boiler (12), wherein the heat accumulator (11) is used to receive converter steam and is connected to the steam collecting cylinder (9) through the steam heating furnace (10), the sintering waste heat boiler (12) is connected to the steam collecting cylinder (9), the steam turbine (1) is connected to a generator (2), and the condenser (3) is connected to a cooling system consisting of a cooling tower (5) and a circulating water pump (6). However, the waste heat utilization of sintering in this system also only utilizes the waste heat of the ring cooler, and does not improve the waste heat utilization efficiency.

[0004] CN212378526U discloses a converter steam waste heat utilization system with an additional self-superheater, comprising a converter, a self-superheater, a steam accumulator, a steam turbine and a generator, wherein the generator is connected to the steam turbine, a condenser is connected to the steam turbine, and a cooling tower is connected to the condenser; a converter drum is provided on the converter, the converter drum is connected to the heat source inlet end on the self-superheater, the heat source outlet end on the self-superheater is connected to the steam inlet of the steam accumulator, the steam outlet of the steam accumulator is connected to the cold source inlet end of the self-superheater, and the cold source outlet end of the self-superheater is connected to the steam turbine; the steam turbine is connected to the condenser used to cool the exhaust steam of the steam turbine. However, the converter steam waste heat utilization system provided by the utility model cannot realize the function of unit energy storage.

[0005] Therefore, in view of the shortcomings of the existing technology, there is an urgent need to provide a device system that can improve the quality of converter saturated steam, improve the efficiency of the converter waste heat unit and realize the energy storage function of the unit. Summary of the invention

[0006] The purpose of the present invention is to provide a solid electric thermal storage body, a device system and a method for utilizing converter waste heat, which couples converter saturated steam with solid electric thermal storage to improve the quality of converter saturated steam, combines with high-efficiency units to increase converter steam power generation, and realizes the energy storage function of the converter waste heat unit.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a solid electric heat storage body, which is arranged vertically in a hollow cylindrical shape, the bottom end of the hollow cavity of the solid electric heat storage body is closed, and an air flow outlet is provided at the top end; the column of the solid electric heat storage body includes a heat storage body and an annular channel arranged in sequence in a direction away from the hollow cavity, the top end of the annular channel is closed, and an air flow inlet is provided at the bottom end; air flow channels are evenly distributed along the radial direction of the heat storage body, wherein the path length of the air flow from the air flow inlet through the air flow channel to the air flow outlet is the same.

[0009] The solid electric heat storage body provided by the present invention is arranged vertically in a hollow cylindrical shape, and the radial flow airflow distribution design can reduce the resistance of the circulating air duct, and the chimney smoke extraction effect is used to reduce the blower output, while also reducing the space occupied.

[0010] Preferably, an electric heating wire is embedded in the heat storage body.

[0011] In a second aspect, the present invention provides a device system for utilizing waste heat from a converter, the device system comprising a steam accumulator, a solid electric heat storage unit, a steam turbine high-pressure cylinder, a steam-water separator, a steam turbine low-pressure cylinder and a condenser connected in sequence along the steam flow direction; the steam turbine high-pressure cylinder and the steam turbine low-pressure cylinder both perform work to generate electricity;

[0012] The solid electric heat storage unit includes a solid electric heat storage body and a waste heat boiler, wherein steam flows through the waste heat boiler, and air circulates in an air circulation loop through a circulation fan, and the air circulation loop includes the solid electric heat storage body and the waste heat boiler.

[0013] The device system for utilizing converter waste heat provided by the present invention couples converter saturated steam heat storage with solid electric heat storage. By setting a solid electric heat storage unit, saturated steam is superheated by a waste heat boiler and then enters the steam turbine unit, so that the steam dryness at the turbine outlet is greatly improved. At the same time, the condenser pressure can be further reduced, thereby improving the unit efficiency. The setting of the solid electric heat storage body enables the unit to have an energy storage function.

[0014] As a further preferred technical solution, the solid electric heat storage body in the device system described in the second aspect adopts the solid electric heat storage body described in the first aspect.

[0015] Preferably, the air circulation loop also includes a shaft seal heater, and the shaft seal leakage of the high-pressure cylinder of the turbine enters the shaft seal heater for heating and then discharges superheated steam, and the superheated steam discharged from the shaft seal heater is mixed with the steam discharged from the steam-water separator and then enters the low-pressure cylinder of the turbine.

[0016] In the present invention, the shaft seal leakage of the high-pressure cylinder of the steam turbine is heated by the shaft seal heater and mixed with the steam discharged from the steam-water separator before entering the low-pressure cylinder of the steam turbine, thereby reducing the loss of steam leakage from the steam turbine and further improving the outlet exhaust steam dryness and the efficiency of the low-pressure cylinder of the steam turbine.

[0017] Preferably, the air circulation loop comprises a solid electric heat storage body, a waste heat boiler, a shaft seal heater and a circulation fan which are sequentially connected along the air flow direction, and the circulation fan is connected to the air flow inlet of the solid electric heat storage body.

[0018] Preferably, an air regulating valve is provided between the shaft seal heater and the circulation fan.

[0019] In a third aspect, the present invention provides a method for utilizing waste heat from a converter, the method comprising the following steps:

[0020] The saturated steam from the converter is superheated by the waste heat boiler and then fed into the high-pressure cylinder of the steam turbine to generate power, wherein the waste heat boiler is connected to a solid electric heat storage body through an air circulation loop;

[0021] The exhaust steam from the high-pressure cylinder of the steam turbine is dehydrated and mixed with the superheated steam discharged from the shaft seal heater before entering the low-pressure cylinder of the steam turbine to generate power. The exhaust steam from the low-pressure cylinder of the steam turbine is condensed, wherein the shaft seal heater is arranged in the air circulation loop.

[0022] The method for utilizing converter waste heat provided by the present invention can effectively improve the outlet steam dryness of the turbine and reduce the condenser pressure by superheating the saturated steam flowing through the steam accumulator. The exhaust steam of the high-pressure cylinder of the turbine is dehydrated and mixed with the superheated steam discharged from the shaft seal heater and then enters the low-pressure cylinder of the turbine to generate power, which can reduce the loss of steam leakage from the turbine and further improve the outlet exhaust steam dryness and the efficiency of the low-pressure cylinder. In the method, steam heat storage and electric heat storage are combined to enable the turbine unit to have an energy storage function. In the heat storage and heat release stages, the turbine unit is in a stable power generation state and the air in the air duct circulates continuously.

[0023] As a further preferred technical solution, the method described in the third aspect is carried out in the device system described in the second aspect.

[0024] Preferably, the saturated steam is 0.6-1.2 MPa(A) saturated steam obtained by buffering the 2-3.2 MPa(A) discontinuous steam generated by the converter through a steam accumulator.

[0025] The pressure of the discontinuous steam is 2-3.2 MPa(A), for example, 2 MPa(A), 2.5 MPa(A) or 3.2 MPa(A), but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the pressure of the saturated steam is 0.8-1.2 MPa(A), for example, 0.8 MPa(A), 1 MPa(A) or 1.2 MPa(A), but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the air flow outlet of the solid electric heat storage body is connected to a waste heat boiler, the waste heat boiler is connected to a shaft seal heater, and the shaft seal heater is connected to the air flow inlet of the solid electric heat storage body through a circulating fan.

[0028] Preferably, the process of the method includes a heat storage stage and a heat release stage. The heat storage stage is: heating the solid electric heat storage body, and the discharged hot air heats the saturated steam and the shaft seal leakage in the shaft seal heater in turn, and then returns to the solid electric heat storage body for circulation heating; the heat release stage is: stopping the heating of the solid electric heat storage body, and the hot air formed by the air flowing radially through the solid electric heat storage body heats the saturated steam and the shaft seal leakage in the shaft seal heater in turn, and then returns to the solid electric heat storage body for circulation heating.

[0029] Preferably, the superheat degree of steam obtained by the superheat treatment is above 60°C, for example, it can be 60°C, 100°C or 239.9°C, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the exhaust steam pressure of the low-pressure cylinder of the steam turbine is ≤0.007 MPa(A), and the exhaust steam dryness is ≥85%.

[0031] The exhaust pressure of the low-pressure cylinder of the steam turbine is ≤0.007 MPa(A), for example, it can be 0.007 MPa(A), 0.005 MPa(A) or 0.002 MPa(A), but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] The exhaust steam dryness of the low-pressure cylinder of the steam turbine is ≥85%, for example, it can be 85%, 86.8% or 90%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the internal efficiency of the steam turbine is ≥86% and the power is ≤25MW.

[0034] The internal efficiency of the steam turbine is ≥86%, for example, it can be 86%, 88% or 90%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] The steam turbine power is ≤25MW, for example, it can be 25MW, 10MW or 9830W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the solid electric heat storage body and the shaft seal heater are arranged vertically, and the starting load of the circulating fan in the heat release stage is lower than the starting load of the circulating fan in the heat storage stage.

[0037] During the heat release stage, the temperature of the solid electric heat storage body is high, the temperature of the discharged hot air is high, the operating density is low, the hot air floats, and after passing through the waste heat boiler, the temperature decreases and the density increases. It sinks in the air circulation loop and can generate circulating power. Therefore, there is no need to provide very high circulating air pressure. The circulating fan can be started at low load and work in conjunction with the regulating air valve to adjust the required circulating air volume.

[0038] Exemplarily, when the device system for utilizing converter waste heat provided by the present invention is applied:

[0039] The discontinuous steam generated by the converter enters the steam accumulator to obtain continuous saturated steam, which is then overheated by the waste heat boiler connected to the solid electric heat storage body and sent to the high-pressure cylinder of the steam turbine to do work. The exhaust steam of the high-pressure cylinder of the steam turbine enters the steam-water separator for dehydration, and is then mixed with the superheated steam obtained by heating the shaft seal heater with the shaft seal leakage gas of the high-pressure cylinder of the steam turbine, and then enters the low-pressure cylinder of the steam turbine to do work, and the exhaust steam enters the condenser;

[0040] In the solid electric thermal storage unit, during the heat storage stage, the electric heating wire works to heat the thermal storage body to store heat, and at the same time, the thermal storage body heats the air in the air duct, and the hot air discharged from the thermal storage body outlet enters the waste heat boiler to heat the saturated steam and enters the shaft seal heater to heat the shaft seal leakage steam, and then the temperature decreases and the density increases, and then returns to the annular channel of the solid electric thermal storage body through the regulating air valve and the circulating fan for circulation and heating; after the heat storage is completed, it enters the heat release stage, the electric heating wire stops working, and the circulating fan starts at low load, and blows air into the annular channel of the solid electric thermal storage body, flows evenly through the thermal storage body in the radial direction, and is heated by the thermal storage body and flows into the hollow cavity of the solid electric thermal storage body, flows upward, enters the waste heat boiler to heat the saturated steam, and the shaft seal heater heats the shaft seal leakage steam, and then returns to the annular channel of the solid electric thermal storage body for circulation and heating.

[0041] During the heat storage stage and the heat release stage, the steam turbine unit is in a stable power generation state, and the air in the air duct circulates continuously; in the heat release stage, the temperature of the heat storage body is relatively high, and the temperature of the discharged hot air is relatively high, so there is no need to provide a very high circulating air volume, and the circulating fan can be started at a low load; in addition, since the density difference between the upper and lower winds can generate circulating power, the circulating fan can be in an inoperative state and work in conjunction with the regulating air valve to adjust the required circulating air volume.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The solid electric heat storage body provided by the present invention is arranged vertically in a hollow cylindrical shape. The radial flow distribution design can reduce the resistance of the circulating air duct, reduce the blower output by using the chimney smoke extraction effect, and also reduce the floor space;

[0044] (2) The device system for utilizing the waste heat of the converter provided by the present invention couples the heat storage of the saturated steam of the converter with the solid electric heat storage. By setting up the solid electric heat storage unit, the saturated steam is superheated by the waste heat boiler and then enters the steam turbine unit, so that the steam dryness at the outlet of the steam turbine is greatly improved, and the condenser pressure can be further reduced, thereby improving the efficiency of the unit; the setting of the solid electric heat storage body enables the unit to have an energy storage function; the shaft seal leakage of the high-pressure cylinder of the steam turbine is heated by the shaft seal heater and mixed with the steam discharged from the steam-water separator before entering the low-pressure cylinder of the steam turbine, thereby reducing the loss of steam leakage from the steam turbine, and at the same time further improving the outlet exhaust steam dryness and improving the efficiency of the low-pressure cylinder of the steam turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 1 is a schematic diagram of the structure of a device system for utilizing converter waste heat provided in Example 1 of the present invention;

[0046] Figure 2 It is a top view of the solid electric thermal storage body provided in Example 1 of the present invention.

[0047] Among them: 1, steam accumulator; 2, turbine high-pressure cylinder; 3, steam-water separator; 4, turbine low-pressure cylinder; 5, condenser; 6, solid electric heat storage body; 7, heat storage body; 8, annular channel; 9, waste heat boiler; 10, shaft seal heater; 11, regulating air valve; 12, circulating fan; 13, electric heating wire. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0049] Example 1

[0050] This embodiment provides a device system for utilizing the waste heat of a converter, such as Figure 1 As shown, the device system includes a steam accumulator 1, a solid electric heat storage unit, a steam turbine high-pressure cylinder 2, a steam-water separator 3, a steam turbine low-pressure cylinder 4 and a condenser 5 connected in sequence along the steam flow direction; the steam turbine high-pressure cylinder 2 and the steam turbine low-pressure cylinder 4 both generate power; the local peak period (8:00-11:00, 17:00-22:00) electricity price is 1.0416 yuan / kWh, the normal period (11:00-17:00, 22:00-24:00) electricity price is 0.6057 yuan / kWh, and the off-peak period (0:00-8:00) electricity price is 0.2535 yuan / kWh;

[0051] The solid electric heat storage unit includes a solid electric heat storage body 6 and a waste heat boiler 9, wherein steam flows through the waste heat boiler 9, and air circulates in an air circulation loop through a circulating fan 12, wherein the air circulation loop includes a solid electric heat storage body 6, a waste heat boiler 9, a shaft seal heater 10, a regulating air valve 11 and a circulating fan 12 which are sequentially connected along the air flow direction, and the circulating fan 12 is connected to the air flow inlet of the solid electric heat storage body 6; the shaft seal leakage of the high-pressure cylinder 2 of the steam turbine enters the shaft seal heater 10 for heating and then discharges superheated steam, and the superheated steam discharged from the shaft seal heater 10 is mixed with the steam discharged from the steam-water separator 3 and then enters the low-pressure cylinder 4 of the steam turbine;

[0052] The solid electric heat storage body 6 is arranged vertically in a hollow cylindrical shape. The top view of the solid electric heat storage body 6 is as follows: Figure 2 As shown, the bottom end of the hollow cavity of the solid electric heat storage body 6 is closed, and an air flow outlet is arranged at the top end; the column of the solid electric heat storage body 6 includes a heat storage body 7 and an annular channel 8 arranged in sequence along the direction away from the hollow cavity, the top end of the annular channel 8 is closed, and an air flow inlet is arranged at the bottom end; air flow channels are evenly distributed along the radial direction of the heat storage body 7, wherein the path length of the air flow from the air flow inlet through the air flow channel to the air flow outlet is the same; an electric heating wire 13 is buried in the heat storage body 7.

[0053] The method for utilizing converter waste heat using the device system comprises the following steps:

[0054] The 2.5MPa discontinuous steam generated by the converter is buffered by the steam accumulator 1 to obtain 1MPa saturated steam, which is superheated by the waste heat boiler 9 with a thermal power of 2433kW. Then, the steam with a temperature of 239.9°C and a flow rate of 57t / h is sent to the high-pressure cylinder 2 of the steam turbine to generate power. The exhaust steam of the high-pressure cylinder 2 of the steam turbine is dehydrated and mixed with the superheated steam discharged by the shaft seal heater 10 and then enters the low-pressure cylinder 4 of the steam turbine to generate power. The exhaust steam of the low-pressure cylinder 4 of the steam turbine is condensed; the exhaust steam pressure of the low-pressure cylinder 4 of the steam turbine is 0.007MPa(A) and the dryness is 86.8%; the internal efficiency of the steam turbine is 86%, the power is 9830W, and it operates 24h;

[0055] The air flow outlet of the solid electric heat storage body 6 is connected to the waste heat boiler 9, the waste heat boiler 9 is connected to the shaft seal heater 10, and the shaft seal heater 10 is connected to the air flow inlet of the solid electric heat storage body 6 through the circulating fan 12;

[0056] The method comprises a heat storage stage and a heat release stage. The heat storage stage comprises: heating the solid electric heat storage body 6, and the discharged hot air sequentially heats the saturated steam and the shaft seal leakage in the shaft seal heater 10, and then returns to the annular channel 8 of the solid electric heat storage body 6 for circulation heating; the heat release stage comprises: stopping heating the solid electric heat storage body 6, and the starting load of the circulating fan 12 is lower than the starting load of the circulating fan 12 in the heat storage stage. The hot air formed by the air flowing radially through the heat storage body 7 sequentially heats the saturated steam and the shaft seal leakage in the shaft seal heater 10, and then returns to the annular channel 8 of the solid electric heat storage body 6 for circulation heating.

[0057] Compared with comparative example 1, the device system in this embodiment consumes 62905 kWh of electricity during the energy storage period (8 hours at low point), which is 43920 kWh more than the conventional steam turbine unit with the same steam volume, the same inlet pressure but the saturation temperature. The electricity conversion efficiency calculated by the energy storage device is 69.8%; the solid electric heat storage body in this embodiment occupies 4.4×6m, and the floor space is greatly reduced; compared with comparative example 1, the daily electricity bill can be saved: (9830-8002)×(1.0416×8+0.6057×8+0.2535×8)-62905×0.2535=11850 yuan.

[0058] Example 2

[0059] This embodiment provides a device system for utilizing waste heat from a converter. The difference from Embodiment 1 is that the solid electric thermal storage body 6 is replaced by a square solid electric thermal storage body arranged in parallel. An air flow channel is arranged in the square solid thermal storage body, but the path of the gas from the inlet to the outlet through different channels is significantly different. The solid thermal storage boiler is relatively short, and the external circulating air duct is arranged in a plane with no significant difference in height. The rest is the same as Embodiment 1.

[0060] Compared with Example 1, the square solid electric heat storage body in this embodiment occupies an area of ​​8×10 m, which is relatively large; at the same time, the resistance of the circulating air duct cannot be reduced, and the blower output increases.

[0061] Comparative Example 1

[0062] This comparative example provides a device system for utilizing waste heat from a converter. The difference from Example 1 is that the device system does not have a shaft seal heater 9 or a steam-water separator 3, and the high-pressure cylinder 2 and the low-pressure cylinder 4 of the steam turbine are integral steam turbines, and the rest are the same as Example 1.

[0063] In this comparative example, since the shaft seal leakage is not recycled, the leakage loss of the steam turbine will increase. At the same time, there is no intermediate dehydration and overheating, which reduces the outlet exhaust steam dryness and the efficiency of the low-pressure cylinder. Compared with Example 1, the exhaust pressure of the steam turbine in this comparative example is 8kPa, the power consumption during the energy storage period is the same as that of Example 1, the power generation of the steam turbine is reduced to 9630kW, and the electric conversion efficiency calculated by the energy storage device is 62.1%.

[0064] Comparative Example 2

[0065] This comparative example provides a device system for utilizing waste heat from a converter, the device system comprising a steam accumulator, a steam-water separator, a steam turbine and a condenser connected in sequence along the steam flow direction, the steam turbine being connected to a generator;

[0066] The method of utilizing converter waste heat by using the device system includes: unstable saturated steam at a pressure of 2MPa flows through a steam accumulator and is reduced in pressure to stable saturated steam at a pressure of 1MPa and 57t / h, which is then removed from the steam by a steam-water separator and sent to a steam turbine for power generation, and the exhaust steam enters a condenser.

[0067] In this comparative example, since the imported steam is saturated steam with a high moisture content, and the exhaust steam dryness at the turbine exhaust outlet must be controlled above 0.85 to prevent blade breakage caused by water erosion, the efficiency of the turbine system can only reach 75%; the turbine power generation capacity of the device is 8002kW.

[0068] In summary, the solid electric heat storage body provided by the present invention is arranged vertically in a hollow cylindrical shape, and the design of the radial flow airflow distribution can reduce the resistance of the circulating air duct, reduce the blower output by utilizing the chimney smoke extraction effect, and also reduce the space occupied; the device system for utilizing the waste heat of the converter provided by the present invention couples the converter saturated steam heat storage with the solid electric heat storage, and by setting a solid electric heat storage unit, the saturated steam is superheated by the waste heat boiler and then enters the steam turbine unit, so that the steam dryness at the outlet of the turbine is greatly improved, and the condenser pressure can be further reduced, thereby improving the efficiency of the unit; the setting of the heat storage body enables the unit to have an energy storage function; the shaft seal leakage of the high-pressure cylinder of the turbine is heated by the shaft seal heater and then mixed with the steam discharged from the steam-water separator and then enters the low-pressure cylinder of the turbine, thereby reducing the loss of steam leakage from the turbine and further improving the outlet exhaust steam dryness and improving the efficiency of the low-pressure cylinder of the turbine.

[0069] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A solid electric heat storage body, characterized in that: The solid electric heat storage body is arranged vertically in a hollow cylindrical shape, the bottom end of the hollow cavity of the solid electric heat storage body is closed, and an air flow outlet is provided at the top end; the column of the solid electric heat storage body includes a heat storage body and an annular channel arranged in sequence in a direction away from the hollow cavity, the top end of the annular channel is closed, and an air flow inlet is provided at the bottom end; air flow channels are evenly distributed along the radial direction of the heat storage body, wherein the path length of the air flow from the air flow inlet through the air flow channel to the air flow outlet is the same.

2. The solid electric thermal storage body according to claim 1, characterized in that: An electric heating wire is embedded in the heat storage body.

3. A device system for utilizing converter waste heat, characterized in that: The device system comprises a steam heat accumulator, a solid electric heat storage unit, a steam turbine high-pressure cylinder, a steam-water separator, a steam turbine low-pressure cylinder and a condenser which are sequentially connected along the steam flow direction; the steam turbine high-pressure cylinder and the steam turbine low-pressure cylinder both perform work to generate electricity; The solid electric heat storage unit includes a solid electric heat storage body and a waste heat boiler, wherein steam flows through the waste heat boiler, and air circulates in an air circulation loop through a circulation fan, and the air circulation loop includes the solid electric heat storage body and the waste heat boiler.

4. The device system according to claim 3, characterized in that: The air circulation loop also includes a shaft seal heater. The shaft seal leakage of the high-pressure cylinder of the steam turbine enters the shaft seal heater for heating and then discharges superheated steam. The superheated steam discharged from the shaft seal heater is mixed with the steam discharged from the steam-water separator and then enters the low-pressure cylinder of the steam turbine.

5. The device system according to claim 4, characterized in that: The air circulation loop includes a solid electric heat storage body, a waste heat boiler, a shaft seal heater and a circulation fan which are sequentially connected along the air flow direction, and the circulation fan is connected to the air flow inlet of the solid electric heat storage body.

6. The device system according to claim 5, characterized in that: An air regulating valve is arranged between the shaft seal heater and the circulating fan.

7. A method for utilizing converter waste heat, characterized in that: The method comprises the following steps: The saturated steam from the converter is superheated by the waste heat boiler and then fed into the high-pressure cylinder of the steam turbine to generate power, wherein the waste heat boiler is connected to a solid electric heat storage body through an air circulation loop; The exhaust steam from the high-pressure cylinder of the steam turbine is dehydrated and mixed with the superheated steam discharged from the shaft seal heater before entering the low-pressure cylinder of the steam turbine to generate power. The exhaust steam from the low-pressure cylinder of the steam turbine is condensed, wherein the shaft seal heater is arranged in the air circulation loop.

8. The method according to claim 7, characterized in that The saturated steam is 0.6-1.2MPa(A) saturated steam obtained by buffering the 2-3.2MPa(A) discontinuous steam generated by the converter through the steam accumulator; Preferably, the air flow outlet of the solid electric heat storage body is connected to a waste heat boiler, the waste heat boiler is connected to a shaft seal heater, and the shaft seal heater is connected to the air flow inlet of the solid electric heat storage body through a circulating fan.

9. The method according to claim 8, characterized in that The method comprises a heat storage stage and a heat release stage. The heat storage stage comprises: heating the solid electric heat storage body, and the discharged hot air sequentially heats the saturated steam and the shaft seal leakage in the shaft seal heater, and then returns to the solid electric heat storage body for circulation heating. The heat release stage comprises: stopping heating the solid electric heat storage body, and the hot air formed by air flowing radially through the solid electric heat storage body sequentially heats the saturated steam and the shaft seal leakage in the shaft seal heater, and then returns to the solid electric heat storage body for circulation heating.

10. The method according to any one of claims 7 to 9, characterized in that: The steam superheat degree obtained by the superheat treatment is above 60°C; Preferably, the exhaust steam pressure of the low-pressure cylinder of the steam turbine is ≤0.007MPa(A), and the exhaust steam dryness is ≥85%; Preferably, the internal efficiency of the steam turbine is ≥86% and the power is ≤25MW.

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