System for prolonging service life of blast furnace gas excess pressure turbine blade

Abstract

The utility model discloses a system for prolonging the service life of blades of a blast furnace gas excess pressure turbine, which belongs to the technical field of blast furnace equipment and comprises a blast furnace, the blast furnace is connected with a dust removal system through a gas pipeline, the dust removal system is connected with a gas inlet of a gas heating device through the gas pipeline, and a gas outlet of the gas heating device is connected with a TRT or BPRT unit through the gas pipeline. The coal gas heating device is connected into the circulating hydrothermal system through a hydrothermal pipeline, and the circulating hydrothermal system further comprises an intermediate water circulating pump and a flue gas cooler. The smoke heat of the hot blast stove is utilized through the circulating hydrothermal system, so that the consumption of an energy medium is reduced; the temperature of inlet gas of the TRT or BPRT unit is increased through the circulating hydrothermal system, so that the problem of corrosion of turbine blades is solved, and the service life of the blades is greatly prolonged; the salt accumulation problem of the TRT or BPRT turbine blade is solved, the scale inhibitor is reduced or omitted, and the operation cost is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of blast furnace equipment, and in particular relates to a system for increasing the service life of blades of a blast furnace gas waste pressure turbine. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] TRT or BPRT is a blast furnace gas residual pressure turbine power generation device. TRT or BPRT uses the pressure energy and heat energy of the byproduct of blast furnace smelting (blast furnace top gas) to convert it into mechanical energy through the expansion work of the turbine, thereby driving the generator to generate electricity. TRT or BPRT devices can also better control the blast furnace top pressure. Compared with the pressure reducing valve group, the stationary blade adjustment of the TRT or BPRT unit can bring more stable blast furnace top pressure, which is beneficial to the control of the blast furnace and the increase of production. In addition, the TRT device does not consume any fuel and is a pollution-free way of power generation; it replaces the traditional pressure reducing valve group and effectively reduces noise pollution.

[0004] With the acceleration of technological progress in the steel industry, the optimization and application of blast furnace production processes and the use of imported ore in some plants have led to a high chloride content in blast furnace gas. After dust removal, although most of the dust has been removed, there is still a certain amount of dust, water vapor and various acidic gases produced by impure blast furnace raw materials in the gas phase, such as H2S, HCL, CO2, etc. Due to the expansion of the unit, the temperature gradually decreases, and the acidic gas dissolves in the condensed water, causing the surface of blades, shells, guide plates and other components to adhere to acidic water for a long time. In addition, factors such as the precipitation of chloride ions in the gas at high temperature cause blade corrosion; at the same time, because CHL in blast furnace gas undergoes recrystallization reaction with NH3 salts and is deposited on the inner wall of the device and the rear blades of TRT or BPRT in the form of NHCL4, salt accumulation and scaling affect the balance of the blades, thereby affecting the service life and power generation of the blades; in addition, when NHCL4 salts are formed, other chloride salts will also be attached, thereby forming a certain thickness of strong acid scaling, and the presence of chloride ions will accelerate the electrochemical corrosion of TRT blades. Once the blades are damaged, the direct impact on the unit is low efficiency and large vibration. For the corrosion and salt accumulation problems of TRT or BPRT blades, targeted measures are urgently needed to effectively solve such problems, ensure the stable operation of the equipment and extend its service life.

[0005] At present, the treatment measures taken by steel enterprises mainly include: passivation treatment of TRT or BPRT blades, spraying of anti-corrosion coatings and adding alkali spray towers downstream of TRT or BPRT. Although these anti-corrosion measures have achieved certain results in the short term, in the long run, these anti-corrosion strategies still have obvious shortcomings. The passivation scale inhibitors used for passivating TRT blades are expensive and require regular shutdowns to clean the TRT or BPRT blades and flow channels; the anti-corrosion coating only alleviates the time of metal acid corrosion, and does not fundamentally eliminate the problem; the addition of alkali spray towers directly leads to a huge loss of coal gas heat, so the existing measures do not fundamentally solve the problem of acid corrosion, and the investment cost is high while also losing coal gas waste heat. Utility Model Content

[0006] In view of the above problems, the utility model provides a system for increasing the service life of blast furnace gas waste pressure turbine blades. It can use the existing hot blast furnace flue gas heat to heat the gas through a circulating water thermal system, fundamentally solving the problem of acid corrosion, thereby increasing the service life of blast furnace gas waste pressure turbine blades.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A system for increasing the service life of blast furnace gas waste pressure turbine blades comprises a blast furnace, wherein the blast furnace is connected to a dust removal system via a gas pipeline, the dust removal system is connected to an air inlet of a gas heater via a gas pipeline, and an air outlet of the gas heater is connected to a TRT or BPRT unit via a gas pipeline; the gas heater is connected to a circulating water heating system via a water heating pipeline, and the circulating water heating system further comprises an intermediate water circulation pump and a flue gas cooler; the flue gas cooler is connected to a hot blast furnace, and the flue gas cooler continuously obtains heat from the flue gas of the hot blast furnace.

[0009] Preferably, the dust removal system is a dry dust removal system, including a gravity dust collector and a bag dust collector.

[0010] Preferably, the TRT or BPRT unit comprises a turbine, and the output end of the turbine is connected to a generator.

[0011] Preferably, the water outlet of the intermediate water circulation pump is connected to the water inlet of the flue gas cooler through a hydrothermal pipe, the water outlet of the flue gas cooler is connected to the water inlet of the gas heater through a hydrothermal pipe, and the water outlet of the gas heater is connected to the water inlet of the intermediate water circulation pump through a hydrothermal pipe.

[0012] Preferably, an expansion water tank is also connected to the circulating hydrothermal system.

[0013] Preferably, the expansion water tank is arranged on the water heating pipeline between the water outlet of the gas heater and the water inlet of the intermediate water circulation pump.

[0014] Preferably, a backup steam heater is also connected to the circulating hydrothermal system.

[0015] Preferably, the standby steam heater is arranged on the water heating pipe between the water outlet of the flue gas cooler and the water inlet of the gas heater.

[0016] Compared with the prior art, the utility model has the following advantages and positive effects:

[0017] 1) The utility model utilizes the flue gas heat of the hot blast furnace through the circulating water heat system, reducing the consumption of energy medium. Only when the heat of the hot blast furnace is insufficient, auxiliary heating is performed through the standby steam heater, which can not only meet the requirements of gas heating, but also save energy;

[0018] 2) The temperature of the inlet gas of the TRT or BPRT unit is heated by the circulating water heat system, which solves the problem of turbine blade corrosion and greatly increases the service life of the blades; solves the problem of salt accumulation on the TRT or BPRT turbine blades, reduces or eliminates the addition of scale inhibitors, and saves operating costs;

[0019] 3) Increasing the temperature of the inlet gas of the TRT or BPRT unit will increase the power generation in a positively correlated manner, that is, the higher the temperature, the greater the corresponding increase in power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0021] Figure 1 It is a system flow chart of an embodiment of the utility model;

[0022] In the figure:

[0023] 1. Blast furnace; 2. Gravity dust collector; 3. Bag dust collector; 4. Gas heater; 5. TRT or BPRT unit; 51. Turbine; 52. Generator; 6. Standby steam heater; 7. Expansion water tank; 8. Intermediate water circulation pump; 9. Flue gas cooler; 10. Hot blast furnace. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0025] The utility model is described in detail below in conjunction with the accompanying drawings. The present embodiment discloses a system for increasing the service life of blast furnace gas residual pressure turbine blades, such as Figure 1 As shown, it includes a blast furnace 1, which is connected to a dust removal system through a gas pipeline, and the dust removal system is connected to an air inlet of a gas heater 4 through a gas pipeline, and an air outlet of the gas heater 4 is connected to a TRT or BPRT unit 5 through a gas pipeline; the gas heater 4 is connected to a circulating water heating system through a water heating pipeline.

[0026] like Figure 1 As shown, in this embodiment, the dust removal system is a dry dust removal system, including a gravity dust collector 2 and a bag dust collector 3. The coal gas in the blast furnace 1 passes through the gravity dust collector 2 and the bag dust collector 3 in turn for dust removal and purification; the TRT or BPRT unit 5 includes a turbine 51, and the output end of the turbine 51 is connected to a generator 52; the electricity generated by the TRT or BPRT unit 5 is transmitted to users for use.

[0027] In this embodiment, the coal gas from the blast furnace 1 is dedusted by a dust removal system and enters the gas heater 4. The gas heater 4 continuously heats the coal gas entering the TRT or BPRT unit 5 through a circulating water thermal system. The heated coal gas enters the TRT or BPRT unit 5 to generate electricity, thereby preventing acidic gases from dissolving in condensed water, thereby preventing blade corrosion of the TRT or BPRT unit.

[0028] like Figure 1 As shown, the circulating water heating system also includes an intermediate water circulating pump 8, the outlet of the intermediate water circulating pump 8 is connected to the water inlet of the flue gas cooler 9 through a water heating pipe, the outlet of the flue gas cooler 9 is connected to the water inlet of the gas heater 4 through a water heating pipe, and the outlet of the gas heater 4 is connected to the water inlet of the intermediate water circulating pump 8 through a water heating pipe. Among them, the flue gas cooler 9 continuously obtains heat from the flue gas of the hot blast furnace 10, and the intermediate circulating water is pumped into the flue gas cooler 9 through the intermediate water circulating pump 8 to absorb heat, and then the intermediate circulating water passes through the gas heater 4 and releases heat to heat the gas transmitted from the dust removal system, and then the intermediate circulating water returns to the flue gas cooler 9 under the action of the intermediate water circulating pump 8 to absorb heat, so as to continuously circulate.

[0029] like Figure 1 As shown, an expansion water tank 7 is also connected to the circulating water heating system. The expansion water tank 7 is arranged on the water heating pipeline between the gas heater 4 and the intermediate water circulation pump 8. When the intermediate water hot water of the circulating water heating system is reduced, water can be replenished into the circulating water heating system through the expansion water tank 7 to ensure the stable heat exchange of the circulating water heating system.

[0030] like Figure 1As shown, a standby steam heater 6 is also connected to the circulating water heating system. The standby steam heater 6 is arranged on the water heating pipeline between the flue gas cooler 9 and the gas heater 4. When the flue gas volume in the hot blast furnace 10 is insufficient and the flue gas cooler 9 cannot obtain sufficient heat, thereby failing to meet the heating requirement of the gas heater 4, the standby steam heater 6 is used to further ensure the temperature of the circulating medium water, thereby meeting the heating requirement of the gas heater 4 and ensuring the gas temperature entering the inlet of the TRT or BPRT unit.

[0031] Working principle:

[0032] The intermediate water circulation pump 8 is turned on, and the intermediate circulating water enters the flue gas cooler 9. The flue gas cooler 9 transfers the heat in the flue gas of the hot blast furnace 10 to the intermediate circulating water, and the intermediate circulating water brings the heat to the gas warmer 4;

[0033] The coal gas in the blast furnace 1 enters the coal gas heater 4 after being dust-removed by the dust removal system. The coal gas absorbs the heat transferred by the intermediate circulating water, and the heated coal gas enters the TRT or BPRT unit to generate electricity.

[0034] The intermediate circulating water enters the flue gas cooler 9 again to absorb heat under the action of the intermediate water circulating pump 8, and thus circulates continuously;

[0035] As the number of cycles increases, the intermediate circulating water in the circulating water heat system decreases, and water is added to the circulating water heat system through the expansion water tank 7 to ensure the heat exchange stability of the circulating water heat system;

[0036] When the flue gas volume in the hot blast stove 10 is insufficient and the flue gas cooler 9 cannot obtain sufficient heat, the intermediate circulating water coming out of the flue gas cooler 9 is further heated by the standby steam heater 6 to ensure the gas heating requirement.

[0037] The advantages of the utility model are:

[0038] 1) The circulating water heat system utilizes the flue gas heat of the hot blast furnace, reducing the consumption of energy media. Only when the heat of the hot blast furnace is insufficient, the standby steam heater is used for auxiliary heating, which can not only meet the requirements of gas heating, but also save energy;

[0039] 2) The temperature of the inlet gas of the TRT or BPRT unit is heated by the circulating water heat system, which solves the problem of turbine blade corrosion and greatly increases the service life of the blades; solves the problem of salt accumulation on the TRT or BPRT turbine blades, reduces or eliminates the addition of scale inhibitors, and saves operating costs;

[0040] 3) Increasing the temperature of the inlet gas of the TRT or BPRT unit will increase the power generation in a positively correlated manner, that is, the higher the temperature, the greater the corresponding increase in power generation.

[0041] Although the above describes the specific implementation methods of the utility model in combination with the accompanying drawings, it is not intended to limit the scope of protection of the utility model. Technical personnel in the relevant field should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the utility model.

Claims

1. A system for increasing the service life of blast furnace gas waste pressure turbine blades, characterized in that: It includes a blast furnace, which is connected to a dust removal system through a gas pipeline, the dust removal system is connected to the air inlet of a gas heater through a gas pipeline, and the air outlet of the gas heater is connected to a TRT or BPRT unit through a gas pipeline; the gas heater is connected to a circulating water heating system through a water heating pipeline, and the circulating water heating system also includes an intermediate water circulation pump and a flue gas cooler; the flue gas cooler is connected to a hot blast furnace, and the flue gas cooler continuously obtains heat from the flue gas of the hot blast furnace.

2. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 1, characterized in that: The dust removal system is a dry dust removal system, including a gravity dust collector and a bag dust collector.

3. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 1, characterized in that: The TRT or BPRT unit comprises a turbine, the output end of which is connected to a generator.

4. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 1, characterized in that: The water outlet of the intermediate water circulation pump is connected to the water inlet of the flue gas cooler through a water-heating pipe, the water outlet of the flue gas cooler is connected to the water inlet of the gas heater through a water-heating pipe, and the water outlet of the gas heater is connected to the water inlet of the intermediate water circulation pump through a water-heating pipe.

5. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 1, characterized in that: An expansion water tank is also connected to the circulating water heating system.

6. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 5, characterized in that: The expansion water tank is arranged on the water heating pipeline between the water outlet of the gas heater and the water inlet of the intermediate water circulation pump.

7. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 1, characterized in that: A standby steam heater is also connected to the circulating water thermal system.

8. A system for increasing the service life of blast furnace gas waste pressure turbine blades as claimed in claim 7, characterized in that: The standby steam heater is arranged on the water heating pipeline between the water outlet of the flue gas cooler and the water inlet of the coal gas heater.

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