Liquid metal waste heat recovery device for high-temperature flue gas of converter

Abstract

The utility model discloses a liquid metal waste heat recovery device for converter high-temperature flue gas, and belongs to the technical field of converter flue gas waste heat recovery. Comprising a high-temperature flue and an evaporator, a first liquid metal heat exchange tube and a second liquid metal heat exchange tube are arranged in the high-temperature flue; the inlet of the evaporator is connected with the feed pump; the outlet of the evaporator is connected with the steam pocket; a liquid metal heater and a liquid metal evaporator are further arranged in the evaporator; an inlet of the first liquid metal heat exchange pipe is connected with an outlet of a first liquid metal storage box. An inlet of the first liquid metal storage box is connected with an outlet of the liquid metal evaporator; an inlet of the liquid metal evaporator is connected with an outlet of the first liquid metal heat exchange tube; an inlet of the second liquid metal heat exchange pipe is connected with an outlet of a second liquid metal storage box. An inlet of the second liquid metal storage box is connected with an outlet of the liquid metal heater; an inlet of the liquid metal heater is connected with an outlet of the second liquid metal heat exchange pipe.

Description

Technical Field

[0001] The utility model belongs to the technical field of converter flue gas waste heat recovery and relates to a device for recovering waste heat from converter high-temperature flue gas and liquid metal. Background Art

[0002] The process flow of the flue gas system during the existing converter smelting is as follows: the converter flue gas at about 1550°C is drawn by the ID fan, passes through the flue gas cooling system (movable smoke hood, heat recovery device and vaporization cooling flue), and the temperature is reduced to 800°C~1200°C before entering the evaporative cooler. There are several dual-medium atomizing cooling nozzles in the evaporative cooler to cool, condition and roughly remove dust from the flue gas. The flue gas temperature is reduced to 150°C~200°C. At the same time, about 40% of the dust is captured by the evaporative cooler, and the coarse dust particles formed are input into the coarse ash silo through the chain conveyor. The flue gas after cooling, coarse dust removal and conditioning enters the cylindrical electrostatic precipitator. After dust removal by the electrostatic precipitator, the dust content of the flue gas is reduced to 10mg / m 3 The fine ash collected by the electrostatic precipitator is discharged into the fine dust bin via a fan-shaped scraper, a bottom chain conveyor, and a fine ash conveying device. Qualified flue gas that has passed the electrostatic precipitator's fine dust removal is cooled to 70°C-80°C in a gas cooler before entering the gas tank. Gas with an oxygen content greater than 2% is released through a flare.

[0003] Currently, the steelmaking industry focuses on two mainstream technologies for cooling converter flue gas: OG (Oxygen Converter Gas Recovery), a technology originating from Japan's Mitsubishi Corporation and renowned for its wet dust removal system; and LT (Lurgi-Thyssen), a dry dust removal technology developed jointly by Germany's Lurgi and Thyssen Steel in the late 1960s. While both methods are widely used in industry, they still suffer from low flue gas heat utilization, significant environmental pollution, and inability to meet energy conservation and environmental protection requirements. Utility Model Content

[0004] The purpose of the utility model is to provide a device for recovering waste heat of liquid metal from high-temperature flue gas in a converter, so as to solve the technical problems of low heat utilization rate of flue gas and serious environmental pollution in the prior art.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the utility model provides a device for recovering waste heat from high-temperature flue gas and liquid metal in a converter, comprising a high-temperature flue and an evaporator; a first liquid metal heat exchange tube and a second liquid metal heat exchange tube are provided in the high-temperature flue; the first liquid metal heat exchange tube is provided near the inlet of the high-temperature flue, and the second liquid metal heat exchange tube is provided near the outlet of the high-temperature flue; the inlet of the evaporator is connected to a water feed pump, and the outlet of the evaporator is connected to a steam drum; a liquid metal heater and a liquid metal evaporator are further provided inside the evaporator; the liquid metal heater is provided near the water feed pump, and the liquid metal evaporator is provided near the steam drum; a first liquid metal storage tank and a second liquid metal storage tank are provided between the high-temperature flue and the evaporator. Liquid metal storage tank; the inlet of the first liquid metal heat exchange tube is connected to the outlet of the first liquid metal storage tank through a liquid metal delivery pipe; the inlet of the first liquid metal storage tank is connected to the outlet of the liquid metal evaporator through a liquid metal delivery pipe; the inlet of the liquid metal evaporator is connected to the outlet of the first liquid metal heat exchange tube through a liquid metal delivery pipe; the inlet of the second liquid metal heat exchange tube is connected to the outlet of the second liquid metal storage tank through a liquid metal delivery pipe; the inlet of the second liquid metal storage tank is connected to the outlet of the liquid metal heater through a liquid metal delivery pipe; the inlet of the liquid metal heater is connected to the outlet of the second liquid metal heat exchange tube through a liquid metal delivery pipe.

[0007] Furthermore, a first heater is provided in the first liquid metal storage tank, and the first heater is located on one side of the first liquid metal storage tank.

[0008] Furthermore, a second heater is provided in the second liquid metal storage tank, and the second heater is located on one side of the second liquid metal storage tank.

[0009] Furthermore, a first liquid metal driving pump is provided in the first liquid metal storage tank, and the first liquid metal driving pump is connected to the outlet of the first liquid metal storage tank.

[0010] Furthermore, a second liquid metal driving pump is provided in the second liquid metal storage tank, and the second liquid metal driving pump is connected to the outlet of the second liquid metal storage tank.

[0011] Furthermore, a smoke filter is provided in the high-temperature flue; the smoke filter is located at the entrance of the high-temperature flue.

[0012] Furthermore, the liquid metal delivery pipeline is made of stainless steel.

[0013] Furthermore, the stainless steel is 316L stainless steel.

[0014] Furthermore, the water provided by the water supply pump is desalted water.

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

[0016] The present utility model discloses a device for recovering waste heat from liquid metal in high-temperature converter flue gas. By arranging a first liquid metal heat exchange tube and a second liquid metal heat exchange tube at different locations in the high-temperature flue (near the inlet and outlet, respectively), the device can fully absorb the waste heat in the converter's high-temperature flue gas, thereby improving the waste heat recovery efficiency. This segmented heat exchange design enables efficient heat exchange between flue gas and liquid metal at an appropriate temperature within different temperature ranges, maximizing the utilization of the flue gas's thermal energy and achieving efficient heat energy recovery. The water in the feedwater pump is heated once by a liquid metal heater and then a second time by a liquid metal evaporator, ultimately forming steam that enters the steam drum for use in subsequent processes. This cascaded utilization of thermal energy effectively improves the energy efficiency of the entire system. The present utility model uses liquid metal as a heat carrier, which has the characteristics of high thermal conductivity, high boiling point, good thermal stability, and corrosion resistance. It can adapt to the high-temperature and highly corrosive converter flue gas environment and ensure long-term stable operation. Furthermore, the use of two independent liquid metal circulation systems (corresponding to the first and second liquid metal heat exchange tubes, respectively) increases system redundancy and flexibility. Even if one system fails, the other can continue to operate, ensuring continuous waste heat recovery. This device converts waste heat from the high-temperature converter flue gas into usable steam or thermal energy, reducing waste heat emissions and helping to lower carbon emissions and energy consumption for enterprises, meeting the requirements of green and sustainable development. Furthermore, by improving energy recovery rates, it also reduces production costs for enterprises and enhances their market competitiveness.

[0017] Furthermore, in the present invention, a first liquid metal driving pump is provided in the first liquid metal storage tank, and a second liquid metal driving pump is provided in the second liquid metal storage tank, so that the liquid metal overcomes the resistance of gravity and circulates.

[0018] Furthermore, a smoke filter is provided in the high-temperature flue of the present invention for separating impurities such as CaO, MgO, FeO, etc. in the flue gas to prevent the impurities from causing impact wear on the first liquid metal heat exchange tube and the second liquid metal heat exchange tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1This is a schematic diagram of the overall structure of the device of the utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the smoke filter of the utility model;

[0022] Figure 3 This is a schematic structural diagram of the liquid metal storage tank of the present utility model;

[0023] Figure 4 This is a schematic structural diagram of the evaporator of the present utility model.

[0024] Among them: 1-soot filter; 2-high-temperature flue; 3-first liquid metal heat exchange tube; 4-second liquid metal heat exchange tube; 5-liquid metal delivery pipeline; 6-second liquid metal drive pump; 7-second liquid metal storage tank; 8-liquid metal block; 9-second heater; 10-evaporator; 11-feedwater pump; 12-liquid metal heater; 13-liquid metal evaporator; 14-steam drum; 15-first heater; 16-first liquid metal storage tank; 17-first liquid metal drive pump. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear to indicate an orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings, or are the orientation or positional relationship in which the product of the present invention is typically placed when in use. These terms are used solely to facilitate the description of the present invention and to simplify the description. They do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] The present invention is described in further detail below with reference to the accompanying drawings:

[0032] See also Figure 1 The present invention discloses a device for recovering waste heat from high-temperature flue gas and liquid metal in a converter, comprising a high-temperature flue 2 and an evaporator 10; a first liquid metal heat exchange tube 3 and a second liquid metal heat exchange tube 4 are provided in the high-temperature flue 2; the first liquid metal heat exchange tube 3 is provided near the inlet of the high-temperature flue 2, and the second liquid metal heat exchange tube 4 is provided near the outlet of the high-temperature flue 2; the inlet of the evaporator 10 is connected to a water feed pump 11, and the outlet of the evaporator 10 is connected to a steam drum 14; see Figure 4 A liquid metal heater 12 and a liquid metal evaporator 13 are also provided inside the evaporator 10; the liquid metal heater 12 is arranged close to the water feed pump 11, and the liquid metal evaporator 13 is arranged close to the steam drum 14; a first liquid metal storage tank 16 and a second liquid metal storage tank 7 are provided between the high-temperature flue 2 and the evaporator 10.

[0033] The inlet of the first liquid metal heat exchange tube 3 is connected to the outlet of the first liquid metal storage tank 16 through the liquid metal delivery pipe 5; the inlet of the first liquid metal storage tank 16 is connected to the outlet of the liquid metal evaporator 13 through the liquid metal delivery pipe 5; the inlet of the liquid metal evaporator 13 is connected to the outlet of the first liquid metal heat exchange tube 3 through the liquid metal delivery pipe 5;

[0034] The inlet of the second liquid metal heat exchange tube 4 is connected to the outlet of the second liquid metal storage tank 7 through the liquid metal delivery pipe 5; the inlet of the second liquid metal storage tank 7 is connected to the outlet of the liquid metal heater 12 through the liquid metal delivery pipe 5; the inlet of the liquid metal heater 12 is connected to the outlet of the second liquid metal heat exchange tube 4 through the liquid metal delivery pipe 5.

[0035] The high-temperature flue gas of the converter of the present invention exchanges heat with the first liquid metal heat exchange tube 3 and the second liquid metal heat exchange tube 4 respectively; the first liquid metal heat exchange tube 3 exchanges heat with the flue gas at a higher temperature, and the liquid metal is heated to 250℃~400℃ before flowing into the liquid metal evaporator 13; the flue gas at a higher temperature is cooled and then exchanges heat with the second liquid metal heat exchange tube 4, and the liquid metal is heated to 100℃~250℃ before flowing into the liquid metal heater 12. This segmented heat exchange design allows the flue gas to efficiently exchange heat with liquid metal at an appropriate temperature in different temperature ranges, maximizing the use of the thermal energy of the flue gas. The water in the water supply pump 11 in the evaporator is first heated to saturated water by the liquid metal heater 12, and then heated to steam by the liquid metal evaporator 13 and enters the steam drum 14. This two-stage heating improves the utilization efficiency of thermal energy.

[0036] In one feasible embodiment of the present invention, a first heater 15 and a first liquid metal drive pump 17 are disposed within a first liquid metal storage tank 16. The first heater 15 is located on one side of the first liquid metal storage tank 16, and the first liquid metal drive pump 17 is connected to the outlet of the first liquid metal storage tank 16. A second heater 9 and a second liquid metal drive pump 6 are disposed within a second liquid metal storage tank 7. The second heater 9 is located on one side of the second liquid metal storage tank 7, and the second liquid metal drive pump 6 is connected to the outlet of the second liquid metal storage tank 7.

[0037] The first liquid metal storage tank 16 and the second liquid metal storage tank 7 are both located at the lowest point of the entire device, so that the liquid metal can flow back into the tank when the device is shut down. Figure 3 The present invention incorporates a heater within the liquid metal storage tank. During operation, liquid metal blocks 8 are placed into the tank from the top, where they are initially melted by the heater to increase fluidity. Furthermore, a liquid metal drive pump is installed at the tank outlet to power the liquid metal's circulation.

[0038] In a feasible embodiment of the present invention, a dust filter 1 is provided in the high temperature flue 2; the dust filter 1 is located at the entrance of the high temperature flue 2. The structure of the dust filter 1 is as follows: Figure 2 As shown, the dust filter 1 is used to separate impurities such as CaO, MgO, FeO, etc. in the flue gas to prevent the impurities from impacting and wearing the liquid metal heat exchange tubes.

[0039] In a feasible embodiment of the present invention, the liquid metal delivery pipe 5 is made of stainless steel, preferably 316L stainless steel, to prevent the liquid metal from corroding the delivery pipe. The water provided by the water pump 11 is demineralized water, ensuring the water quality is qualified and protecting the evaporator 10 from corrosion.

[0040] The present invention discloses a method for recovering waste heat from high-temperature flue gas and liquid metal in a converter. The method is based on the above-mentioned device for recovering waste heat from high-temperature flue gas and liquid metal in a converter, and includes the following steps:

[0041] The high-temperature flue gas of the converter enters from the inlet of the high-temperature flue 2 and exchanges heat with the first liquid metal heat exchange tube 3. The liquid metal in the first liquid metal heat exchange tube 3 is heated to 250℃~400℃ after heat exchange and then enters the liquid metal evaporator 13. The high-temperature flue gas of the converter is cooled once.

[0042] The high-temperature converter flue gas, after the primary cooling, exchanges heat with the second liquid metal heat exchange tube 4; the liquid metal in the second liquid metal heat exchange tube 4 is heated to 100°C~250°C after the heat exchange, and then enters the liquid metal heater 12; the high-temperature converter flue gas is cooled for the second time and then discharged from the outlet of the high-temperature flue 2;

[0043] The desalted water in the water feed pump 11 first flows through the liquid metal heater 12 and is heated to saturated water by the liquid metal at 100℃~250℃; then it flows through the liquid metal evaporator 13 and is heated by the liquid metal at 250℃~400℃ to generate saturated steam and enter the steam drum 14.

[0044] Example:

[0045] The embodiment of the present utility model adopts the aforementioned waste heat recovery device for liquid metal from high-temperature flue gas in a converter, wherein the design and manufacture of the evaporator 10 complies with GB150-2011 "Pressure Vessels", GB151-2014 "Heat Exchangers" and TSG21-2016 "Safety Technical Supervision Regulations for Stationary Pressure Vessels". The liquid metal adopts gallium-based liquid metal (Ga80In20). The density of gallium-based liquid metal (Ga80In20) is 6.093 g / cm3, with a low melting point (16°C) and a high boiling point (2500°C). When converted from liquid to solid, the expansion rate is 3.1%. This embodiment uses liquid metal as a cooling medium for heat exchange. Liquid metal has excellent high thermal performance and its heat dissipation capacity is far superior to traditional water cooling. The parameter comparison of gallium-based liquid metal (Ga80In20) and water as heat transfer medium is shown in Table 1:

[0046] Table 1 Heat transfer medium parameters when water and liquid metal are used as cooling media

[0047]

[0048] When the device of this embodiment is in use, high-temperature flue gas at 800°C to 1000°C enters the high-temperature flue 2, exchanges heat with the first and second liquid metal heat exchange tubes 3 and 4, respectively, and cools to 170°C to 200°C before being discharged. Desalted water from the feedwater pump 11 is heated by the liquid metal heater 12 and the liquid metal evaporator 13, respectively, generating saturated steam at 2.0 MPa and 215°C. This steam enters the steam drum 14, which can be used for sale or for power generation, achieving a win-win situation of energy conservation and emission reduction, and realizing both social and economic benefits.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A device for recovering waste heat from high-temperature flue gas and liquid metal in a converter, characterized in that: The invention comprises a high-temperature flue (2) and an evaporator (10); a first liquid metal heat exchange tube (3) and a second liquid metal heat exchange tube (4) are arranged in the high-temperature flue (2); the first liquid metal heat exchange tube (3) is arranged near the inlet of the high-temperature flue (2), and the second liquid metal heat exchange tube (4) is arranged near the outlet of the high-temperature flue (2); the inlet of the evaporator (10) is connected to the water supply pump (11), and the outlet of the evaporator (10) is connected to the steam drum (14); a liquid metal heater (12) and a liquid metal evaporator (13) are further arranged in the evaporator (10); the liquid metal heater (12) is arranged near the water supply pump (11), and the liquid metal evaporator (13) is arranged near the steam drum (14); a first liquid metal storage tank (16) and a second liquid metal storage tank (16) are arranged between the high-temperature flue (2) and the evaporator (10). box (7); the inlet of the first liquid metal heat exchange tube (3) is connected to the outlet of the first liquid metal storage box (16) through the liquid metal delivery pipe (5); the inlet of the first liquid metal storage box (16) is connected to the outlet of the liquid metal evaporator (13) through the liquid metal delivery pipe (5); the inlet of the liquid metal evaporator (13) is connected to the outlet of the first liquid metal heat exchange tube (3) through the liquid metal delivery pipe (5); the inlet of the second liquid metal heat exchange tube (4) is connected to the outlet of the second liquid metal storage box (7) through the liquid metal delivery pipe (5); the inlet of the second liquid metal storage box (7) is connected to the outlet of the liquid metal heater (12) through the liquid metal delivery pipe (5); the inlet of the liquid metal heater (12) is connected to the outlet of the second liquid metal heat exchange tube (4) through the liquid metal delivery pipe (5).

2. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: A first heater (15) is provided in the first liquid metal storage tank (16), and the first heater (15) is located on one side of the first liquid metal storage tank (16).

3. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: A second heater (9) is provided in the second liquid metal storage tank (7), and the second heater (9) is located on one side of the second liquid metal storage tank (7).

4. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: A first liquid metal driving pump (17) is provided in the first liquid metal storage tank (16), and the first liquid metal driving pump (17) is connected to the outlet of the first liquid metal storage tank (16).

5. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: A second liquid metal drive pump (6) is provided in the second liquid metal storage tank (7), and the second liquid metal drive pump (6) is connected to the outlet of the second liquid metal storage tank (7).

6. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: A smoke filter (1) is provided in the high-temperature flue (2); the smoke filter (1) is located at the entrance of the high-temperature flue (2).

7. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: The liquid metal delivery pipeline (5) is made of stainless steel.

8. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 7, characterized in that: The stainless steel is 316L stainless steel.

9. The device for recovering waste heat from high-temperature flue gas and liquid metal in a converter according to claim 1, characterized in that: The water provided by the water supply pump (11) is desalted water.

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