Hydrogen energy ironmaking system with gas turbine

Abstract

The utility model relates to the technical field of hydrogen energy ironmaking, and discloses a hydrogen energy ironmaking system with a gas turbine, which comprises a shaft furnace, a washer, a heat exchanger, a heating furnace, a process gas compressor and a main fan, the cracking conveying pipeline sequentially passes through the heat exchanger and the heating furnace and then is connected with the shaft furnace, and a process gas compressor is arranged on the cracking conveying pipeline. The process gas compressor is driven by the first gas turbine to operate, the main fan is driven by the second gas turbine to operate, and compared with an existing process gas compressor and an existing main fan which need to be driven by external electric energy to work, the system is driven by heat energy generated by combustion of furnace top recycled gas, conveying of the external electric energy to an ironmaking system is reduced, and energy consumption is reduced. Meanwhile, optimization of the resource utilization rate is achieved, and comprehensive utilization of energy is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen energy ironmaking, in particular to a hydrogen energy ironmaking system with a gas turbine. Background Art

[0002] The traditional blast furnace ironmaking system consists of a blast furnace body and several auxiliary systems. During production, various furnace materials are loaded in batches from the furnace top, and hot air is continuously blown in from the lower tuyere of the blast furnace. Liquid slag iron is obtained during the continuous smelting process and is regularly discharged from the furnace slag iron port. The coal gas that has a series of reactions with the furnace materials overflows from the furnace top. The advantages of blast furnace reactors are perfect technology, large-scale equipment and long life, but their defects are also very obvious: first, blast furnace smelting cannot do without coke, and high-quality coking coal is becoming less and less; second, the environmental pollution is serious, especially the water pollutants, dust emissions, and sintering SO2 dust emissions of the coke oven; third, the entire refining process requires repeated heating, cooling, carbon addition, and decarbonization, and the utilization of resources and thermal energy is unreasonable, and the energy recycling rate is low; fourth, carbon is used as a reducing agent, and the process is long, the investment is large, and the cost is high.

[0003] In order to overcome the above shortcomings, relevant researchers have developed gas-based steel reduction, that is, using hydrogen as a reducing agent. The use of hydrogen for smelting avoids carbon contamination of molten iron during the reduction process, changes the problem of molten steel pollution caused by repeated oxidation-reduction reactions in the traditional process, reduces repeated heating, and reduces system energy consumption. At present, there are about a dozen production processes using gas-based reduction to produce iron, but the Midrex method is the most important direct reduction iron production process, and its production of reduced iron accounts for 64.1% of the world's total direct reduction iron production. The reduction process principle of the Midrex method is as follows:

[0004] Cracking of natural gas: CH4+H2O=CO+3H2 CH4+CO2=2CO+2H2

[0005] Reduction reaction of iron ore: Fe2O3+3CO=2Fe+3CO2 Fe2O3+3H2=2Fe+3H2O

[0006] Carburizing reaction: Fe+2CO=Fe3C+CO2

[0007] Midrex process Figure 2 and Figure 3:Natural gas enters the heating furnace for cracking to produce reducing gas (a mixture of carbon monoxide and hydrogen with a content of more than 95%). The reducing gas enters the furnace from the middle part of the vertical furnace and reacts with the hematite loaded in the upper part to form sponge iron. After carburizing reaction, it is cooled and discharged from the lower part of the vertical furnace. The top gas is discharged from the top of the vertical furnace and forms top recovery gas after purification. Part of the top recovery gas is used for combustion and heating, and part returns to the heating furnace to participate in cracking again. At present, the heat energy carried by the top recovery gas is not utilized in the ironmaking process of the Midrex method, resulting in a waste of energy. Secondly, it is necessary to provide electric energy from the outside to drive the process gas compressor and the main fan to work, so that the energy utilization rate of the entire system is not high. Utility Model Content

[0008] The utility model provides a hydrogen energy ironmaking system with a gas turbine, which solves the problem that the current Midrex method requires external electric energy to drive the process gas compressor and the main fan to work.

[0009] A hydrogen energy ironmaking system with a gas turbine comprises a vertical furnace, a scrubber, a heat exchanger, a heating furnace, a process gas compressor and a main fan, wherein the vertical furnace is connected to the scrubber through a furnace top recovery pipeline, the scrubber is connected to a cracking delivery pipeline, the cracking delivery pipeline is connected to the vertical furnace after passing through the heat exchanger and the heating furnace in sequence, a process gas compressor is arranged on the cracking delivery pipeline, the process gas compressor is located between the scrubber and the heat exchanger, and the process gas compressor is driven and operated by a first gas turbine;

[0010] The main fan is driven by the second gas turbine.

[0011] Furthermore, a first combustion gas branch is connected to the cracking transmission pipeline, and the first combustion gas branch is communicated with the first combustion chamber. At the same time, air is compressed into the first combustion chamber through a first air compressor; the first gas turbine is driven by combustion of the gas in the first combustion chamber.

[0012] Furthermore, a second combustion gas branch is connected to the cracking transmission pipeline between the heat exchanger and the heating furnace, and the second combustion gas branch is connected to the second combustion chamber. At the same time, air is compressed into the second combustion chamber through a second air compressor; the second gas turbine is driven by the combustion of the gas inside the second combustion chamber.

[0013] Furthermore, the first combustion chamber is connected to a first flue gas branch pipe, the second combustion chamber is connected to a second flue gas branch pipe, the first flue gas branch pipe and the second flue gas branch pipe are respectively connected to the boiler, and the boiler is connected to the chimney through the tail gas pipe.

[0014] Furthermore, the boiler is connected to the steam turbine through a high-temperature steam delivery pipe, the steam turbine is connected to the generator, and a low-temperature steam return pipe is provided between the steam turbine and the boiler, and a condenser is provided on the low-temperature steam return pipe.

[0015] Furthermore, the scrubber is connected to the heating furnace through a combustion heat pipe, and the heating furnace is also connected to a supplementary gas source pipe.

[0016] Furthermore, the main fan is connected to a combustion-supporting air delivery pipe, and the combustion-supporting air delivery pipe is connected to the heating furnace after passing through a heat exchanger.

[0017] The utility model has the following beneficial effects:

[0018] (1) The ironmaking system of the utility model is provided with a combustion chamber and a gas turbine. At the same time, part of the top recovery gas discharged from the vertical furnace and washed by the scrubber is transported to the combustion chamber for combustion, driving the gas turbine to operate, and then driving the process gas compressor and the main fan through the gas turbine. Compared with the existing process gas compressor and the main fan which require external electric energy to drive, the utility model generates heat energy through the combustion of the top recovery gas, thereby reducing the supply of external electric energy to the ironmaking system.

[0019] (2) The ironmaking system of the utility model is provided with a boiler, a steam turbine and a generator. The flue gas generated after combustion in the combustion chamber carries a large amount of heat. This part of the flue gas with heat heats the boiler to form high-temperature steam. The high-temperature steam drives the steam turbine to operate, and then drives the generator to generate electricity, thereby realizing multi-level recycling of energy and reducing energy loss.

[0020] (3) The ironmaking system of the utility model improves the existing hydrogen ironmaking system by adding a combustion chamber, a gas turbine, a boiler, and a generator. These additional equipment are not only fully coordinated and arranged in the existing hydrogen ironmaking system, but also achieve the optimization of resource utilization, greatly improving the comprehensive utilization of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the ironmaking system of the utility model;

[0022] Figure 2 This is a flow chart of the MIDREX ironmaking process;

[0023] Figure 3 This is a schematic diagram of the MIDREX process for ironmaking.

[0024] In the figure: 1-vertical furnace; 2-scrubber; 3-heat exchanger; 4-heating furnace; 5-chimney; 6-process gas compressor; 601-first gas turbine; 602-first combustion chamber; 603-first air compressor; 7-main fan; 701-second gas turbine; 702-second combustion chamber; 703-second air compressor; 8-boiler; 9-steam turbine; 10-generator; 11-condenser. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] refer to Figure 1 The utility model provides a hydrogen energy ironmaking system with a gas turbine, including a vertical furnace 1, a scrubber 2, a heat exchanger 3, a heating furnace 4, a process gas compressor 6, a main fan 7, a boiler 8, a steam turbine 9, a generator 10 and a gas turbine, and the gas turbine includes a first gas turbine 601 and a second gas turbine 701.

[0027] The vertical furnace 1 is connected to the scrubber 2 through the furnace top recovery pipeline. Since the hematite in the vertical furnace 1 undergoes a reduction reaction with the reducing gas to generate the furnace top gas, the furnace top gas contains impurities such as sulfide and particulate matter, and is washed and purified by the scrubber 2 to form the furnace top recovery gas, and the carbon monoxide and hydrogen content in the furnace top recovery gas is about 70%. The scrubber 2 is connected to a cracking and conveying pipeline, which is connected to the vertical furnace 1 after passing through the heat exchanger 3 and the heating furnace 4 in turn, and is used to recycle the furnace top recovery gas containing about 70% carbon monoxide and hydrogen. The carbon dioxide in the furnace top recovery gas is combined with the injected natural gas for secondary cracking in the heating furnace 4 to form a reducing gas with a carbon monoxide and hydrogen content of more than 95%, and the reducing gas is conveyed to the vertical furnace 1 to reduce the trivalent iron ions in the hematite.

[0028] A process gas compressor 6 is provided on the cracking delivery pipeline, and the process gas compressor 6 is located between the scrubber 2 and the heat exchanger 3, and is used to pressurize and deliver the furnace top recycled gas. The process gas compressor 6 is driven and operated by the first gas turbine 601. Specifically, the cracking delivery pipeline is connected with a first combustion gas delivery branch pipe, and the first combustion gas delivery branch pipe is connected to the first combustion chamber 602. At the same time, air is pressed into the first combustion chamber 602 through the first air compressor 603. After part of the furnace top recycled gas is burned in the first combustion chamber 602, heat energy is generated to drive the first gas turbine 601 to operate. The first gas turbine 601 is connected to the process gas compressor 6 through a transmission shaft and a sleeve, thereby driving the process gas compressor 6 to work.

[0029] A second combustion gas branch is connected to the cracking transmission pipeline between the heat exchanger 3 and the heating furnace 4, and the second combustion gas branch is connected to the second combustion chamber 702. At the same time, air is compressed into the second combustion chamber 702 through the second air compressor 703. Part of the furnace top recycled gas generates heat energy after combustion in the second combustion chamber 702 to drive the second gas turbine 701 to operate. The second gas turbine 701 is connected to the main fan 7 through another set of transmission shafts and sleeves, thereby driving the main fan 7 to work.

[0030] Since a large amount of heat is required to generate reducing gas, the heating furnace 4 is connected to the scrubber 2 through a combustion heat pipe, and the furnace top recovery gas containing carbon monoxide and hydrogen is transported to the heating furnace 4 for combustion to generate heat energy. The main blower 7 is used to blow oxygen-containing air into the heating furnace 4 for combustion support. The main blower 7 is connected to a combustion-supporting air delivery pipe, which is connected to the heating furnace 4 after passing through the heat exchanger 3. Since the heat of the furnace top recovery gas in the cracking delivery pipeline is recovered by the heat exchanger 3 when passing through the heat exchanger 3, and the combustion-supporting air in the combustion-supporting air delivery pipe is heated by the heat exchanger 3 when passing through the heat exchanger 3, the heat energy of the furnace top recovery gas is fully utilized. The heating furnace 4 is also connected to a supplementary gas source pipe. When the furnace top recovery gas transported to the heating furnace 4 by the combustion heat pipe is insufficient, natural gas can be transported from the outside to help generate reducing gas.

[0031] The first combustion chamber 602 is connected to a first flue gas branch pipe, and the second combustion chamber 702 is connected to a second flue gas branch pipe. The first flue gas branch pipe and the second flue gas branch pipe are respectively connected to the boiler 8. The flue gas generated after the combustion of the furnace top recovery gas in the first combustion chamber 602 and the second combustion chamber 702 has a large amount of heat. By transporting this part of the flue gas to the boiler 8, it is used to heat the water in the boiler 8 to form high-temperature steam, making full use of the heat in the flue gas. The boiler 8 is connected to the steam turbine 9 through a high-temperature steam delivery pipe. The high-temperature steam formed in the boiler 8 drives the steam turbine 9 to operate. The steam turbine 9 is connected to the generator 10 through a connecting shaft and a shaft connector. The operation of the steam turbine 9 drives the generator 10 to work, which is used to generate electrical energy.

[0032] A low-temperature steam return pipe is also provided between the steam turbine 9 and the boiler 8 , and a condenser 11 is provided on the low-temperature steam return pipe for condensing the low-temperature steam after the heat has been utilized into water and then transporting it to the boiler 8 for use.

[0033] The boiler 8 is connected to the chimney 5 through the tail gas pipe, and the flue gas after the heat is used is discharged to the chimney 5 and then discharged into the atmosphere. Similarly, the tail gas after combustion in the heating furnace 4 is also discharged to the atmosphere through the chimney 5. Since the main components of the recycled gas on the top of the furnace are carbon monoxide and hydrogen, after sufficient combustion, the flue gas mainly contains carbon dioxide and moisture, does not contain other pollutants, and will not cause pollution to the environment.

[0034] The vertical furnace 1, scrubber 2, heat exchanger 3 and heating furnace 4 in this embodiment are all conventional equipment used in MIDREX ironmaking, and the steam turbine 9 and gas turbine are conventional equipment, and their structures and working principles are not described in detail.

[0035] The above is only a preferred embodiment of the utility model, which does not represent all possible forms of the utility model, and the protection scope of the utility model is not limited to such special statements and embodiments. According to the technical inspirations disclosed by the utility model, various other modifications and improvements that do not deviate from the essence of the utility model are made, and these modifications and improvements are still within the protection scope of the utility model.

Claims

1. A hydrogen-powered ironmaking system with a gas turbine, comprising a vertical furnace (1), a scrubber (2), a heat exchanger (3), a heating furnace (4), a process gas compressor (6) and a main fan (7), wherein the vertical furnace (1) is connected to the scrubber (2) via a furnace top recovery pipeline, the scrubber (2) is connected to a cracking conveying pipeline, and the cracking conveying pipeline is connected to the vertical furnace (1) after passing through the heat exchanger (3) and the heating furnace (4) in sequence, characterized in that: The process gas compressor (6) is arranged on the cracking delivery pipeline, the process gas compressor (6) is located between the scrubber (2) and the heat exchanger (3), and the process gas compressor (6) is driven by the first gas turbine (601); The main fan (7) is driven and operated by the second gas turbine (701).

2. The hydrogen-powered ironmaking system with a gas turbine according to claim 1, characterized in that: The cracking transmission pipeline is connected to a first combustion gas transmission branch pipe, which is communicated with a first combustion chamber (602). At the same time, air is compressed into the first combustion chamber (602) through a first air compressor (603); the first gas turbine (601) is driven by combustion of the gas inside the first combustion chamber (602).

3. The hydrogen-powered ironmaking system with a gas turbine according to claim 2, characterized in that: A second combustion gas supply branch pipe is connected to the cracking and conveying pipeline between the heat exchanger (3) and the heating furnace (4), and the second combustion gas supply branch pipe is connected to the second combustion chamber (702). At the same time, air is compressed into the second combustion chamber (702) through a second air compressor (703); the second gas turbine (701) is driven by the combustion of the gas inside the second combustion chamber (702).

4. The hydrogen-powered ironmaking system with a gas turbine according to claim 3, characterized in that: The first combustion chamber (602) is connected to a first flue gas branch pipe, and the second combustion chamber (702) is connected to a second flue gas branch pipe. The first flue gas branch pipe and the second flue gas branch pipe are respectively connected to a boiler (8), and the boiler (8) is connected to a chimney (5) via a tail gas pipe.

5. The hydrogen-powered ironmaking system with a gas turbine according to claim 4, characterized in that: The boiler (8) is connected to a steam turbine (9) via a high-temperature steam delivery pipe, the steam turbine (9) is connected to a generator (10), a low-temperature steam return pipe is provided between the steam turbine (9) and the boiler (8), and a condenser (11) is provided on the low-temperature steam return pipe.

6. The hydrogen-powered ironmaking system with a gas turbine according to claim 1, characterized in that: The scrubber (2) is connected to the heating furnace (4) via a combustion heat pipe, and the heating furnace (4) is also connected to a supplementary gas source pipe.

7. The hydrogen-powered ironmaking system with a gas turbine according to any one of claims 1 to 6, characterized in that: The main fan (7) is connected to a combustion-supporting air delivery pipe, and the combustion-supporting air delivery pipe is connected to the heating furnace (4) after passing through the heat exchanger (3).

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