A multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency

Abstract

This invention discloses a multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency. It belongs to the field of waste heat power generation technology in steel enterprises. To utilize waste heat steam sources of different qualities in steel enterprises for power generation, the multi-steam source combined power generation system includes an electric furnace waste heat system (1), a converter waste heat system (2), a sintering waste heat system (3), a rolling mill heating furnace waste heat system (4), a steam storage tank (5), a gas-fired steam superheater (6), and a power generation system (7). The waste heat steam in the electric furnace waste heat system (1) and the converter waste heat system (2) can enter the steam storage tank (5). This multi-steam source combined power generation system utilizes multiple or multi-stage steam sources of different qualities in steel enterprises, improving the utilization efficiency of waste heat resources in steel enterprises.

Description

Technical Field

[0001] This invention relates to the field of waste heat power generation technology in steel enterprises, specifically a multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency. Background Technology

[0002] Industrial enterprises, especially steel mills, possess numerous waste heat resources that can be utilized to generate steam for external transmission. Examples include sintering waste heat steam, converter waste heat steam, electric arc furnace waste heat steam, and rolling mill heating furnace waste heat steam. Sintering waste heat steam, due to its higher temperature, is typically used in power generation systems. However, the large quantities of saturated steam generated through vaporization cooling in converter steelmaking, electric arc furnace steelmaking, and rolling mill heating furnace systems cannot be widely used by industrial users due to steam quality issues and the intermittent nature of converter and electric arc furnace processes. Most of the steam is used for low-quality applications such as domestic or heating systems via the plant's low-pressure steam network. Furthermore, because user consumption is small and lacks continuity, a significant amount of waste heat saturated steam is still released into the atmosphere, reducing the overall economic benefits of the enterprise and causing environmental pollution.

[0003] Therefore, combining steam sources of different qualities before supplying them to industrial users or for power generation to increase efficiency has become a popular and widely accepted technical approach in recent years. Conventional combined steam sources simply deliver steam of different qualities to the user side, relying on the user to absorb the differences between the steam sources to achieve the combined effect. However, this method typically places higher demands on users, requiring a wide range of usable steam parameters, and the system is complex, often requiring separate auxiliary equipment for different steam qualities, resulting in high investment and maintenance costs. Summary of the Invention

[0004] In order to utilize waste heat steam sources of different qualities in steel enterprises for power generation, this invention provides a multi-steam source combined power generation system that improves efficiency by using a gas-fired superheater. The multi-steam source combined power generation system that improves efficiency by using a gas-fired superheater combines multiple or multi-stage steam sources of different qualities in steel enterprises for comprehensive utilization, thereby improving the utilization efficiency of waste heat resources in steel enterprises.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A multi-steam source combined power generation system utilizing a gas-fired superheater to improve efficiency includes an electric furnace waste heat system, a converter waste heat system, a sintering waste heat system, a rolling mill heating furnace waste heat system, a steam storage tank, a gas-fired steam superheater, and a power generation system. Waste heat steam from the electric furnace waste heat system can enter the steam storage tank or the gas-fired steam superheater; waste heat steam from the converter waste heat system can enter the steam storage tank or the gas-fired steam superheater; steam from the steam storage tank can enter the gas-fired steam superheater; waste heat steam from the rolling mill heating furnace waste heat system can enter the gas-fired steam superheater; the gas-fired steam superheater heats the steam, and the heated steam enters the turbine of the power generation system; waste heat steam from the sintering waste heat system can also enter the turbine of the power generation system.

[0007] The electric furnace waste heat system includes an electric furnace waste heat steam supply pipeline, the converter waste heat system includes a converter waste heat steam supply pipeline, and the gas-fired steam superheater includes a first steam inlet, a first steam outlet, a second steam inlet, and a second steam outlet. The electric furnace waste heat steam supply pipeline and the converter waste heat steam supply pipeline are connected to the first steam inlet of the gas-fired steam superheater through a steam mixing header.

[0008] The multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency includes a steam storage tank, which is connected to a steam mixing header via a first steam inlet / outlet pipe.

[0009] The gas-fired steam superheater is an integrated structure containing a furnace, which is equipped with a first heat absorption tube and a second heat absorption tube.

[0010] The gas-fired steam superheater has a split structure, containing two furnace chambers. One furnace chamber contains a first heat absorption tube, and the other furnace chamber contains a second heat absorption tube.

[0011] The first steam inlet and the first steam outlet are located at the two ends of the first heat absorption tube, respectively, and the second steam inlet and the second steam outlet are located at the two ends of the second heat absorption tube, respectively.

[0012] The waste heat system of the rolling mill heating furnace is connected to the second steam inlet of the gas-fired steam superheater through the waste heat steam supply pipeline of the rolling mill heating furnace.

[0013] The power generation system includes a condensing steam turbine with supplemental steam. The first steam outlet of the gas-fired steam superheater is connected to the main steam inlet of the condensing steam turbine with supplemental steam via the main steam input pipeline, and the second steam outlet of the gas-fired steam superheater is connected to the supplemental steam inlet of the condensing steam turbine with supplemental steam via the supplemental steam input pipeline.

[0014] The sintering waste heat system includes a sintering high-pressure steam generation pipeline and a sintering low-pressure steam generation pipeline. The sintering high-pressure steam generation pipeline is connected to the main steam input pipeline, and the sintering low-pressure steam generation pipeline is connected to the make-up steam input pipeline.

[0015] The steam outlet of the supplementary steam condensing turbine is connected to a condenser, which converts the steam discharged from the steam outlet of the supplementary steam condensing turbine into water.

[0016] The beneficial effects of this invention are:

[0017] 1. Integrate waste heat steam sources with various parameters and qualities within the steel plant and apply them to the power generation system to improve the utilization rate of waste heat steam.

[0018] 2. Peak shaving and valley filling of intermittent waste heat resources from electric furnaces and converters, ensuring stable external transmission and improving steam parameter quality.

[0019] 3. When improving the quality of saturated steam with different parameters, gas-fired steam superheating devices are used. Depending on the application scenario, integrated or split structures can be adopted to improve the energy efficiency of waste heat resources of different qualities, and all of them are integrated into the power generation system. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 This is a schematic diagram of the integrated structure of the gas-fired steam superheater in the multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency, as described in this invention.

[0022] Figure 2 This is a schematic diagram of a split-type structure for the gas-fired steam superheater device in the multi-steam combined power generation system that utilizes a gas-fired superheater device to improve efficiency, as described in this invention.

[0023] The annotations in the attached figures are explained as follows:

[0024] 1. Electric furnace waste heat system; 2. Converter waste heat system; 3. Sintering waste heat system; 4. Rolling mill heating furnace waste heat system; 5. Steam accumulator; 6. Gas-fired steam superheater; 7. Power generation system; 8. Valves; 9. Condenser;

[0025] 11. Waste heat steam supply pipeline for electric furnace;

[0026] 21. Converter waste heat steam supply pipeline;

[0027] 31. Sintered high-pressure steam generation pipeline; 32. Sintered low-pressure steam generation pipeline;

[0028] 41. Waste heat steam supply pipeline for steel rolling heating furnace;

[0029] 51. First steam inlet and outlet pipes;

[0030] 61. First steam inlet; 62. First steam outlet; 63. Second steam inlet; 64. Second steam outlet; 65. Steam mixing header; 66. Furnace chamber; 67. First heat absorber tube; 68. Second heat absorber tube;

[0031] 71. Steam Turbine with Makeup Steam; 72. Main Steam Input Pipeline; 73. Main Steam Inlet; 74. Makeup Steam Input Pipeline; 75. Makeup Steam Inlet. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] A multi-steam source combined power generation system utilizing a gas-fired superheater for efficiency improvement includes an electric furnace waste heat system 1, a converter waste heat system 2, a sintering waste heat system 3, a rolling mill heating furnace waste heat system 4, a steam storage tank 5, a gas-fired steam superheater 6, and a power generation system 7. The waste heat steam from the electric furnace in the electric furnace waste heat system 1 can be stored in the steam storage tank 5 or heated in the gas-fired steam superheater 6. Similarly, the waste heat steam from the converter in the converter waste heat system 2 can be stored in the steam storage tank 5 or heated in the gas-fired steam superheater 6. The steam in the steam storage tank 5 can be heated in the gas-fired steam superheater 6. The waste heat steam from the rolling mill heating furnace in the waste heat system 4 can also be heated in the gas-fired steam superheater 6. The gas-fired steam superheater 6 heats the steam, and the heated steam can then enter the turbine of the power generation system 7 (driving the turbine to generate electricity). The waste heat steam from the sintering waste heat system 3 can also enter the turbine of the power generation system 7 (driving the turbine to generate electricity). Figure 1 As shown.

[0034] In this embodiment, the electric furnace waste heat system 1 includes an electric furnace waste heat steam supply pipeline 11, and the electric furnace waste heat steam generated by the electric furnace waste heat system 1 enters the electric furnace waste heat steam supply pipeline 11. The converter waste heat system 2 includes a converter waste heat steam supply pipeline 21, and the converter waste heat steam generated by the converter waste heat system 2 enters the converter waste heat steam supply pipeline 21.

[0035] In this embodiment, the gas-fired steam superheater 6 includes a first steam inlet 61, a first steam outlet 62, a second steam inlet 63, and a second steam outlet 64. The electric furnace waste heat steam supply line 11 and the converter waste heat steam supply line 21 are connected to the first steam inlet 61 of the gas-fired steam superheater 6 through a steam mixing header 65. The electric furnace waste heat steam and the converter waste heat steam enter the gas-fired steam superheater 6 through the steam mixing header 65.

[0036] In this embodiment, a valve 8 is provided on the steam mixing header 65, which can regulate the gas flow rate of the steam mixing header 65. The multi-steam source combined power generation system utilizing a gas-fired superheater for efficiency improvement may include a steam storage tank 5, which is connected to the steam mixing header 65 via a first steam inlet / outlet pipe 51. The structure of the steam storage tank 5 is roughly the same as that of a conventional sealed gas storage tank or liquid storage tank. The outer side of the steam storage tank 5 is provided with a good insulation layer to store the heat energy in the steam, such as... Figure 1 As shown.

[0037] When the steam flow rate in the electric furnace waste heat steam supply pipeline 11 is high, the electric furnace waste heat steam in the electric furnace waste heat system 1 can enter the steam storage tank 5 and the gas-fired steam superheater 6. When the steam flow rate in the electric furnace waste heat steam supply pipeline 11 is low, the steam stored in the steam storage tank 5 can enter the gas-fired steam superheater 6. When the steam flow rate in the converter waste heat steam supply pipeline 21 is high, the converter waste heat steam in the converter waste heat system 2 can enter the steam storage tank 5 and the gas-fired steam superheater 6. When the steam flow rate in the converter waste heat steam supply pipeline 21 is low, the steam stored in the steam storage tank 5 can enter the gas-fired steam superheater 6. The steam storage tank 5 and valve 8 work together to achieve peak shaving and valley filling of intermittent waste heat resources from the electric furnace and converter, ensuring stable external delivery and improving steam parameter quality. In addition, valve 8 can be installed on each of the other pipelines.

[0038] In this embodiment, the gas-fired steam superheater 6 has a structure basically the same as that of an existing gas-fired heating furnace. The gas-fired steam superheater 6 includes a furnace chamber 66, which is heated by burning combustible gas within it. The combustible gas burned in the gas-fired steam superheater 6 can be coal gas recovered from electric furnaces, converters, and sintering machines in steel enterprises, thereby achieving full utilization of energy. The gas nozzles of the gas-fired steam superheater 6 can be connected to the electric furnace, converter, and sintering machine via gas delivery pipelines.

[0039] In this embodiment, the gas-fired steam superheater 6 can be an integrated structure, that is, the gas-fired steam superheater 6 contains a furnace 66, and the furnace 66 is provided with a first heat absorption pipe 67 and a second heat absorption pipe 68, such as... Figure 1As shown. Alternatively, the gas-fired steam superheater 6 can also be a split structure, that is, the gas-fired steam superheater 6 contains two furnaces 66, one furnace 66 is equipped with a first heat absorption tube 67, and the other furnace 66 is equipped with a second heat absorption tube 68, as shown. Figure 2 As shown.

[0040] In this embodiment, the first steam inlet 61 and the first steam outlet 62 are located at the two ends of the first heat absorption tube 67, and the second steam inlet 63 and the second steam outlet 64 are located at the two ends of the second heat absorption tube 68, respectively. Steam can enter the first heat absorption tube 67 and the second heat absorption tube 68 to be heated. The waste heat system 4 of the rolling mill heating furnace is connected to the second steam inlet 63 of the gas-fired steam superheating device 6 through the waste heat steam supply pipeline 41 of the rolling mill heating furnace. The waste heat steam generated by the waste heat system 4 of the rolling mill heating furnace enters the waste heat steam supply pipeline 41 of the rolling mill heating furnace, such as... Figure 1 As shown.

[0041] In this embodiment, the power generation system 7 includes a condensing steam turbine 71 with supplemental steam. The first steam outlet 62 of the gas-fired steam superheater 6 is connected to the main steam inlet 73 of the condensing steam turbine 71 via the main steam input pipeline 72. The second steam outlet 64 of the gas-fired steam superheater 6 is connected to the supplemental steam inlet 75 of the condensing steam turbine 71 via the supplemental steam input pipeline 74.

[0042] In this embodiment, the sintering waste heat system 3 includes a high-pressure sintering steam generation pipeline 31 and a low-pressure sintering steam generation pipeline 32. High-pressure superheated steam (approximately 1.6 MPa-2.6 MPa) generated by the sintering waste heat system 3 enters the high-pressure sintering steam generation pipeline 31, while low-pressure superheated steam (approximately 0.3 MPa-0.8 MPa) enters the low-pressure sintering steam generation pipeline 32. The high-pressure sintering steam generation pipeline 31 is connected to the main steam input pipeline 72, and the low-pressure sintering steam generation pipeline 32 is connected to the makeup steam input pipeline 74. A condenser 9 is connected to the steam outlet of the makeup steam condensing turbine 71. The condenser 9 converts the steam discharged from the steam outlet of the makeup steam condensing turbine 71 into water for use as makeup water in the waste heat boiler.

[0043] The following describes the working process of the multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency.

[0044] When the steam flow rate in the electric furnace waste heat steam supply pipeline 11 is high, the electric furnace waste heat steam in the electric furnace waste heat system 1 enters the steam accumulator 5 for storage and the gas-fired steam superheater 6 for heat absorption. When the steam flow rate in the electric furnace waste heat steam supply pipeline 11 is low, the steam stored in the steam accumulator 5 enters the gas-fired steam superheater 6 for heat absorption. When the steam flow rate in the converter waste heat steam supply pipeline 21 is high, the converter waste heat steam in the converter waste heat system 2 enters the steam accumulator 5 for storage and the gas-fired steam superheater 6 for heat absorption. When the steam flow rate in the converter waste heat steam supply pipeline 21 is low, the steam stored in the steam accumulator 5 enters the gas-fired steam superheater 6 for heat absorption. The gas-fired steam superheater 6 releases heat through combustion of the gas, thereby heating the electric furnace waste heat steam and the converter waste heat steam. After being heated, the electric furnace waste heat steam and the converter waste heat steam enter the main steam inlet 73 of the supplementary steam condensing turbine 71, driving the supplementary steam condensing turbine 71 to generate electricity.

[0045] Waste heat steam from the steel rolling furnace in the waste heat system 4 enters the gas-fired steam superheater 6. The gas in the superheater 6 burns and releases heat, thus heating the waste heat steam. This heated steam then enters the make-up steam inlet 75 of the condensing steam turbine 71, driving the turbine to generate electricity. Coal gas recovered by the steel enterprise also enters the gas-fired steam superheater 6 for combustion and heat release.

[0046] The high-pressure superheated steam generated by the sintering waste heat system 3 enters directly into the main steam inlet 73 of the supplementary steam condensing turbine 71 via the sintering high-pressure steam production pipeline 31, driving the supplementary steam condensing turbine 71 to generate electricity. The low-pressure superheated steam generated by the sintering waste heat system 3 enters directly into the supplementary steam inlet 75 of the supplementary steam condensing turbine 71 via the sintering low-pressure steam production pipeline 32, driving the supplementary steam condensing turbine 71 to generate electricity.

[0047] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical solutions, and embodiments of the present invention can be freely combined and used together.

Claims

1. A multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency, characterized in that, The multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency includes an electric furnace waste heat system (1), a converter waste heat system (2), a sintering waste heat system (3), a steel rolling heating furnace waste heat system (4), a steam storage tank (5), a gas-fired steam superheater (6), and a power generation system (7). The waste heat steam from the electric furnace in the waste heat system (1) can enter the steam storage tank (5) or the gas-fired steam superheater (6). The waste heat steam from the converter in the waste heat system (2) can enter the steam storage tank (5) or the gas-fired steam superheater (6). The steam in the steam storage tank (5) can enter the gas-fired steam superheater (6). The waste heat steam from the rolling mill in the waste heat system (4) can enter the gas-fired steam superheater (6). The gas-fired steam superheater (6) can heat the steam, and the heated steam can enter the turbine of the power generation system (7). The waste heat steam from the sintering in the waste heat system (3) can also enter the turbine of the power generation system (7). The electric furnace waste heat system (1) includes an electric furnace waste heat steam supply pipeline (11), the converter waste heat system (2) includes a converter waste heat steam supply pipeline (21), and the gas-fired steam superheater (6) includes a first steam inlet (61), a first steam outlet (62), a second steam inlet (63), and a second steam outlet (64). The electric furnace waste heat steam supply pipeline (11) and the converter waste heat steam supply pipeline (21) are connected to the first steam inlet (61) of the gas-fired steam superheater (6) through a steam mixing header (65). The gas-fired steam superheater (6) has a split structure. The gas-fired steam superheater (6) contains two furnace chambers (66). One furnace chamber (66) is equipped with a first heat absorption tube (67), and the other furnace chamber (66) is equipped with a second heat absorption tube (68). The power generation system (7) includes a condensing steam turbine (71) with a supplementary steam. The first steam outlet (62) of the gas-fired steam superheater (6) is connected to the main steam inlet (73) of the condensing steam turbine (71) through the main steam input pipeline (72). The second steam outlet (64) of the gas-fired steam superheater (6) is connected to the supplementary steam inlet (75) of the condensing steam turbine (71) through the supplementary steam input pipeline (74). The sintering waste heat system (3) includes a sintering high-pressure steam generation pipeline (31) and a sintering low-pressure steam generation pipeline (32). The sintering high-pressure steam generation pipeline (31) is connected to the main steam input pipeline (72), and the sintering low-pressure steam generation pipeline (32) is connected to the supplementary steam input pipeline (74).

2. The multi-steam source combined power generation system for improving efficiency using a gas-fired superheater as described in claim 1, characterized in that, The multi-steam source combined power generation system that utilizes a gas-fired superheater to improve efficiency includes a steam storage tank (5), which is connected to a steam mixing header (65) via a first steam inlet / outlet pipe (51).

3. The multi-steam source combined power generation system for improving efficiency using a gas-fired superheater as described in claim 1, characterized in that, The first steam inlet (61) and the first steam outlet (62) are located at the two ends of the first heat absorption tube (67), and the second steam inlet (63) and the second steam outlet (64) are located at the two ends of the second heat absorption tube (68).

4. The multi-steam source combined power generation system for improving efficiency using a gas-fired superheater as described in claim 1, characterized in that, The waste heat system (4) of the steel rolling furnace is connected to the second steam inlet (63) of the gas-fired steam superheater (6) via the waste heat steam supply pipeline (41) of the steel rolling furnace.

5. The multi-steam source combined power generation system for improving efficiency using a gas-fired superheater as described in claim 1, characterized in that, The steam outlet of the supplementary steam condensing turbine (71) is connected to a condenser (9), which converts the steam discharged from the steam outlet of the supplementary steam condensing turbine (71) into water.

Images