High-temperature coal gas waste heat recovery power generation device for smelting reduction ironmaking process

Abstract

The utility model relates to the field of power generation, in particular to a smelting reduction ironmaking process high-temperature coal gas waste heat recovery power generation device which comprises a boiler, a steam turbine and a power generator which are sequentially connected, and further comprises a condenser, a heat exchanger, a deaerator, a circulating water pool and a smelting reduction furnace. The heat exchanger, the deaerator and the circulating water tank are respectively connected with the condenser, the heat exchanger is connected with the circulating water tank, the heat exchanger is externally connected with a cold water pipe and a hot water pipe, the outer end of the cold water pipe is provided with a cold water inlet, the outer end of the hot water pipe is provided with a hot water outlet, the smelting reduction furnace is connected with a hot water outlet branch pipe, and the hot water outlet branch pipe is provided with a filtering structure. The outer end of the hot water outlet branch pipe is communicated with the hot water pipe. According to the high-temperature coal gas waste heat recovery power generation device, water resources in the power generation process through high-temperature coal gas waste heat recovery in the smelting reduction ironmaking process can be recycled, heat of the water resources is also recycled, and energy is efficiently saved from two aspects.

Description

Technical Field

[0001] This utility model relates to the field of power generation, specifically to a high-temperature coal gas waste heat recovery power generation device for molten reduction ironmaking process. Background Technology

[0002] Smelting reduction ironmaking is a process that directly reduces iron ore to molten iron at high temperatures to produce liquid iron. The composition of the product is quite similar to that of blast furnace iron. Currently mature smelting reduction ironmaking processes include the COREX, Hismelt, and FINEX processes. Among these, the COREX and Hismelt processes are capable of large-scale production. The core of the Hismelt process is the smelting reduction furnace, which includes a lower molten iron pool and an upper secondary combustion zone. In the lower molten iron pool, pulverized coal is injected into the pool at high temperatures through a bottom-blown lance. Carbon dissolves in the molten iron and reacts with iron oxides to produce CO and molten iron. In the upper secondary combustion zone, hot air and CO and H2 from the coal gas are combusted to release heat. This heat is transferred to the molten iron pool through the slag-iron mixture to maintain the reaction temperature.

[0003] Currently, the technology of using waste heat recovery for power generation is quite common in various industries. The application of waste heat recovery power generation technology to the smelting reduction ironmaking process has also been disclosed. For example, the existing technology with application number 202020479224.6 and title "A High-Temperature Coal Gas Waste Heat Recovery Power Generation System for Smelting Reduction Ironmaking Process" discloses that the system uses a medium-temperature and medium-pressure waste heat boiler to recover the waste heat and energy of high-temperature coal gas, and is equipped with a high-efficiency medium-temperature and medium-pressure steam turbine generator set. In addition to supplying the electricity for the entire smelting reduction ironmaking production, the generated electricity can also be surplus and sent out, thus maximizing the benefits in terms of energy utilization.

[0004] However, the aforementioned waste heat recovery power generation system still has drawbacks in its use. It only discloses the use of waste heat boilers to recover and generate electricity from the waste heat of high-temperature coal gas, but the treatment of water resources in the whole system is not disclosed, and it is unknown whether water resources can be recycled in the whole system. In addition, whether the heat of water resources can be recovered and reused is also an urgent problem to be solved. Utility Model Content

[0005] To address the aforementioned problems, the main objective of this invention is to provide a high-temperature gas waste heat recovery power generation device for molten reduction ironmaking. This device can recycle water resources during the high-temperature gas waste heat recovery power generation process of molten reduction ironmaking, and also recover and reuse the heat of the water resources, thus saving energy efficiently from both aspects.

[0006] To achieve the above objectives, this utility model provides a high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process, comprising a boiler, a steam turbine, and a generator connected in sequence, and further comprising a condenser, a heat exchanger, a deaerator, a circulating water tank, and a molten reduction furnace. The condenser is connected to the steam turbine, and the heat exchanger, deaerator, and circulating water tank are respectively connected to the condenser and the circulating water tank. The deaerator is connected to the boiler, and an inlet pump is provided on the pipe connecting the deaerator and the boiler. The device also includes a chemical water workshop, which is connected to the boiler, deaerator, and molten reduction furnace. A cold water pipe and a hot water pipe are connected to the outside of the heat exchanger. The cold water pipe has a cold water inlet at its outer end, and the hot water pipe has a hot water outlet at its outer end. A hot water outlet branch pipe is connected to the molten reduction furnace, and a filter structure is provided on the hot water outlet branch pipe. The outer end of the hot water outlet branch pipe is connected to the hot water pipe.

[0007] Furthermore, the condenser is equipped with condenser tubes and water inlet pipes. The condenser tubes include a steam inlet and a condensation outlet, and the water inlet pipes include a water inlet and a water outlet. The exhaust steam output end of the steam turbine is connected to the steam inlet, the input end of the deaerator is connected to the condensation outlet, the circulating water pool is connected to the water inlet, and the heat exchanger is connected to the water outlet.

[0008] Furthermore, one end of the low-temperature side water pipe of the heat exchanger is connected to the cold water inlet and the other end is connected to the hot water outlet, while one end of the high-temperature side water pipe is connected to the condenser and the other end is connected to the circulating water pool.

[0009] Furthermore, the chemical water workshop supplies softened water to the deaerator.

[0010] Furthermore, it also includes an integrated greywater treatment system, which is connected to both the circulating water tank and the melting reduction furnace. The integrated greywater treatment system treats the wastewater in the circulating water tank into greywater and then transports it to the melting reduction furnace.

[0011] Furthermore, valves are installed on the cold water pipes, hot water pipes, and hot water outlet branch pipes.

[0012] Furthermore, a dust removal device is installed outside the boiler, and the gas treated by the dust removal device is discharged through a tall chimney.

[0013] Furthermore, it also includes a controller, which is electrically connected to the condenser, heat exchanger, deaerator, circulating water tank and molten reduction furnace respectively.

[0014] The beneficial effects of this utility model through the above technical solution include:

[0015] (1) The waste heat recovery power generation device of this utility model can realize the recycling of water resources in the process of high temperature gas waste heat recovery in the molten reduction ironmaking process, and some of the heat in the water resources is recovered and reused.

[0016] (2) In addition, the waste heat recovery power generation device of this utility model can also recover the heat in the water flushing process in the melting reduction furnace. Combined with the waste heat recovery of water resources in the above power generation device, it can provide a continuous supply of high temperature water to meet the needs of multiple occasions. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 This is a schematic diagram of the structural connections of the high-temperature coal gas waste heat recovery power generation device for the molten reduction ironmaking process of this utility model.

[0019] Explanation of reference numerals in the attached figures

[0020] 1. Boiler; 2. Steam turbine; 3. Generator; 4. Condenser; 5. Heat exchanger; 6. Deaerator; 7. Circulating water tank; 8. Melting reduction furnace; 9. Inlet water pump; 10. Chemical water workshop; 11. Filtration structure; 12. Dust removal device. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Many specific details are set forth in the following description to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] like Figure 1 The diagram shown illustrates the structural connections of the high-temperature gas waste heat recovery power generation device for the smelting reduction ironmaking process of this invention. The device comprises a boiler 1, a steam turbine 2, and a generator 3 connected in sequence. Additionally, it includes a condenser 4, a heat exchanger 5, a deaerator 6, a circulating water tank 7, and a smelting reduction furnace 8. The condenser 4 is connected to the steam turbine 2. The heat exchanger 5, deaerator 6, and circulating water tank 7 are all connected to the condenser 4. The heat exchanger 5 is connected to the circulating water tank 7. The deaerator 6 is connected to the boiler 1. A water inlet pump 9 is installed on the pipeline connecting the deaerator 6 and the boiler 1. The deaerator 6 also includes a chemical water workshop 10, which is connected to the boiler 1, the deaerator 6 and the molten reduction furnace 8. The chemical water workshop 10 supplies softened water to the deaerator 6. A cold water pipe and a hot water pipe are connected to the heat exchanger 5. The cold water pipe has a cold water inlet at its outer end and the hot water pipe has a hot water outlet at its outer end. A hot water outlet branch pipe is connected to the molten reduction furnace 8. A filter structure 11 is installed on the hot water outlet branch pipe. The outer end of the hot water outlet branch pipe is connected to the hot water pipe. Valves are installed on the cold water pipe, the hot water pipe and the hot water outlet branch pipe.

[0023] In addition, the condenser 4 is equipped with condenser pipes and water inlet pipes. The condenser pipes include a steam inlet and a condenser outlet, and the water inlet pipes include a water inlet and a water outlet. The steam turbine 2 is connected to the steam inlet, the deaerator 6 is connected to the condenser outlet, the circulating water pool 7 is connected to the water inlet, and the heat exchanger 5 is connected to the water outlet. One end of the low-temperature side water pipe of the heat exchanger 5 is connected to the cold water inlet, and the other end is connected to the hot water outlet. One end of the high-temperature side water pipe is connected to the condenser 4, and the other end is connected to the circulating water pool 7.

[0024] The waste heat recovery power generation device of this utility model is also equipped with an integrated greywater treatment device (not shown in the figure). The integrated greywater treatment device is connected to the circulating water tank 7 and the melting reduction furnace 8 respectively. That is, the integrated greywater device is located on the pipeline between the circulating water tank 7 and the melting reduction furnace 8. The integrated greywater treatment device treats the sewage in the circulating water tank 7 into greywater and then transports it into the melting reduction furnace 8.

[0025] In other embodiments, a dust removal device 12 is also connected to the outside of the boiler 1. The gas treated by the dust removal device 12 is discharged through a tall chimney. The dust removal device 12 can be a flue gas desulfurization tower, flue gas denitrification equipment, etc., to achieve desulfurization and denitrification of the flue gas of the boiler 1 in order to meet emission standards.

[0026] This utility model also includes a controller, which is electrically connected to the condenser 4, heat exchanger 5, deaerator 6, circulating water tank 7, molten reduction furnace 8, and various valves. It should be noted that all electrical components appearing in the application documents are connected to the controller and power supply. The control method is implemented through the controller. The control system of the controller is directly obtainable by those skilled in the art and belongs to common knowledge. Therefore, it will not be described in detail, but it can all be implemented.

[0027] The working principle of this utility model's high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process is as follows: High-temperature gas generated in the molten reduction ironmaking process enters the device. Boiler 1 is equipped with a forced draft fan, secondary draft fan, and induced draft fan. The water-cooled walls inside the boiler absorb the heat released by the combustion of the high-temperature gas, generating saturated steam. The saturated steam further absorbs heat through a heat exchanger to become superheated steam, which then enters the turbine 2 through the main steam pipeline. The turbine 2 performs expansion work, driving the generator 3 to convert mechanical energy into electrical energy, which is then transmitted to the power grid for user use. The exhaust steam from turbine 2 enters the inlet of condenser 4 from its exhaust steam output end. Circulating water from the circulating water pool 7 is also transported within condenser 4. Because the exhaust steam temperature of turbine 2 is still relatively high, it can be used in the condenser... Under the action of condenser 4, the heat of the steam is transferred to the circulating water, and the exhaust steam eventually becomes condensate and flows out from the condenser outlet. The circulating water in condenser 4 from the circulating water pool 7 absorbs the heat of the exhaust steam and is transported to heat exchanger 5. It enters the high-temperature side pipe in heat exchanger 5, while the low-temperature side pipe in heat exchanger 5 is connected to external low-temperature or normal-temperature water. The circulating water heated here can heat the external low-temperature or normal-temperature water and flow to the hot water pipe. The circulating water in heat exchanger 5 flows back to the circulating water pool 7, thereby reusing water resources. The condensate in condenser 4 flows to deaerator 6 through the condenser outlet and re-enters boiler 1 as an organic working fluid under the action of water pump 9. In addition, chemical water workshop 10 also supplies chemical water to boiler 1 and softened water to deaerator 6.

[0028] Furthermore, the high-temperature coal gas waste heat recovery power generation device of this utility model is applicable to the smelting reduction ironmaking step of the Hismelt process. Since the smelting reduction furnace 8 in this process step needs to undergo water flushing slag treatment, specifically, the high-temperature slag is rapidly cooled and crushed to form granular slag for subsequent utilization and processing. However, a large amount of heat is generated during the water flushing slag process. Since the heat generated by the water flushing slag process in the prior art is not high, it is difficult to recover and reuse it. Therefore, this utility model improves this process step and provides a waste heat recovery power generation device that combines the waste heat from the water flushing slag in the smelting reduction furnace 8 with the heat recovered by the heat exchanger 5. The slag flushing water in the smelting reduction furnace 8 enters the hot water outlet branch pipe and is filtered through the filter structure 11, neutralizing it with the hot water on the hot water pipe. This can provide a sustainable and uninterrupted heat supply to the outside. Although the heat from the water flushing slag in the smelting reduction furnace 8 is not high, the heat obtained by the condenser 4 in the heat exchanger 5 is relatively high. After the two are neutralized, they can fully meet the hot water supply needs in various situations.

[0029] Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process, comprising a boiler (1), a steam turbine (2), and a generator (3) connected in sequence, characterized in that, It also includes a condenser (4), a heat exchanger (5), a deaerator (6), a circulating water tank (7), and a molten reduction furnace (8). The condenser (4) is connected to the steam turbine (2). The heat exchanger (5), the deaerator (6), and the circulating water tank (7) are respectively connected to the condenser (4). The heat exchanger (5) is connected to the circulating water tank (7). The deaerator (6) is connected to the boiler (1). A water inlet pump (9) is installed on the pipeline connecting the deaerator (6) and the boiler (1). The system also includes a chemical water workshop (10), which is connected to the boiler (1), deaerator (6) and molten reduction furnace (8) respectively. A cold water pipe and a hot water pipe are connected to the heat exchanger (5). The cold water pipe has a cold water inlet at its outer end and a hot water outlet at its outer end. A hot water outlet branch pipe is connected to the molten reduction furnace (8). A filter structure (11) is provided on the hot water outlet branch pipe. The outer end of the hot water outlet branch pipe is connected to the hot water pipe.

2. The high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process according to claim 1, characterized in that, The condenser (4) is provided with a condenser pipe and a water inlet pipe. The condenser pipe includes a steam inlet and a condenser outlet. The water inlet pipe includes a water inlet and a water outlet. The exhaust steam output end of the steam turbine (2) is connected to the steam inlet. The input end of the deaerator (6) is connected to the condenser outlet. The circulating water pool (7) is connected to the water inlet. The heat exchanger (5) is connected to the water outlet.

3. The high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process according to claim 1, characterized in that, One end of the low-temperature side water pipe of the heat exchanger (5) is connected to the cold water inlet and the other end is connected to the hot water outlet. One end of the high-temperature side water pipe is connected to the condenser (4) and the other end is connected to the circulating water pool (7).

4. The high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process according to claim 1, characterized in that, The chemical water workshop (10) supplies softened water to the deaerator (6).

5. The high-temperature gas waste heat recovery power generation device for molten reduction ironmaking process according to claim 1, characterized in that, It also includes an integrated greywater treatment device, which is connected to the circulating water tank (7) and the melting reduction furnace (8) respectively. The integrated greywater treatment device treats the sewage in the circulating water tank (7) into greywater and then transports it to the melting reduction furnace (8).

6. The high-temperature gas waste heat recovery power generation device for smelting reduction ironmaking process according to any one of claims 1 to 5, characterized in that, Valves are installed on the cold water pipe, hot water pipe, and hot water outlet branch pipe.

7. The high-temperature gas waste heat recovery power generation device for smelting reduction ironmaking process according to any one of claims 1 to 5, characterized in that, The boiler (1) is also equipped with a dust removal device (12), and the gas treated by the dust removal device (12) is discharged through a tall chimney.

8. The high-temperature gas waste heat recovery power generation device for smelting reduction ironmaking process according to any one of claims 1 to 5, characterized in that, It also includes a controller, which is electrically connected to the condenser (4), heat exchanger (5), deaerator (6), circulating water tank (7) and molten reduction furnace (8), respectively.

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